basisu_transcoder.cpp

// basisu_transcoder.cpp
// Copyright (C) 2019-2024 Binomial LLC. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "basisu_transcoder.h"
#include "basisu_containers_impl.h"

#include "basisu_astc_hdr_core.h"

#define BASISU_ASTC_HELPERS_IMPLEMENTATION
#include "basisu_astc_helpers.h"

#include <limits.h>

#if defined(_MSC_VER)
	#include <intrin.h> // For __popcnt intrinsic
#endif

#ifndef BASISD_IS_BIG_ENDIAN
// TODO: This doesn't work on OSX. How can this be so difficult?
//#if defined(__BIG_ENDIAN__) || defined(_BIG_ENDIAN) || defined(BIG_ENDIAN)
//	#define BASISD_IS_BIG_ENDIAN (1)
//#else
	#define BASISD_IS_BIG_ENDIAN (0)
//#endif
#endif

#ifndef BASISD_USE_UNALIGNED_WORD_READS
	#ifdef __EMSCRIPTEN__
		// Can't use unaligned loads/stores with WebAssembly.
		#define BASISD_USE_UNALIGNED_WORD_READS (0)
	#elif defined(_M_AMD64) || defined(_M_IX86) || defined(__i386__) || defined(__x86_64__)
		#define BASISD_USE_UNALIGNED_WORD_READS (1)
	#else
		#define BASISD_USE_UNALIGNED_WORD_READS (0)
	#endif
#endif

// Using unaligned loads and stores causes errors when using UBSan. Jam it off.
#if defined(__has_feature)
#if __has_feature(undefined_behavior_sanitizer)
#undef BASISD_USE_UNALIGNED_WORD_READS
#define BASISD_USE_UNALIGNED_WORD_READS 0
#endif
#endif

#define BASISD_SUPPORTED_BASIS_VERSION (0x13)

#ifndef BASISD_SUPPORT_KTX2
	#error Must have defined BASISD_SUPPORT_KTX2
#endif

#ifndef BASISD_SUPPORT_KTX2_ZSTD
#error Must have defined BASISD_SUPPORT_KTX2_ZSTD
#endif

// Set to 1 for fuzz testing. This will disable all CRC16 checks on headers and compressed data.
#ifndef BASISU_NO_HEADER_OR_DATA_CRC16_CHECKS
	#define BASISU_NO_HEADER_OR_DATA_CRC16_CHECKS 0
#endif

#ifndef BASISD_SUPPORT_DXT1
	#define BASISD_SUPPORT_DXT1 1
#endif

#ifndef BASISD_SUPPORT_DXT5A
	#define BASISD_SUPPORT_DXT5A 1
#endif

// Disable all BC7 transcoders if necessary (useful when cross compiling to Javascript)
#if defined(BASISD_SUPPORT_BC7) && !BASISD_SUPPORT_BC7
	#ifndef BASISD_SUPPORT_BC7_MODE5
		#define BASISD_SUPPORT_BC7_MODE5 0
	#endif
#endif // !BASISD_SUPPORT_BC7

// BC7 mode 5 supports both opaque and opaque+alpha textures, and uses less memory BC1.
#ifndef BASISD_SUPPORT_BC7_MODE5
	#define BASISD_SUPPORT_BC7_MODE5 1
#endif

#ifndef BASISD_SUPPORT_PVRTC1
	#define BASISD_SUPPORT_PVRTC1 1
#endif

#ifndef BASISD_SUPPORT_ETC2_EAC_A8
	#define BASISD_SUPPORT_ETC2_EAC_A8 1
#endif

// Set BASISD_SUPPORT_UASTC to 0 to completely disable support for transcoding UASTC files.
#ifndef BASISD_SUPPORT_UASTC
	#define BASISD_SUPPORT_UASTC 1
#endif

#ifndef BASISD_SUPPORT_ASTC
	#define BASISD_SUPPORT_ASTC 1
#endif

// Note that if BASISD_SUPPORT_ATC is enabled, BASISD_SUPPORT_DXT5A should also be enabled for alpha support.
#ifndef BASISD_SUPPORT_ATC
	#define BASISD_SUPPORT_ATC 1
#endif

// Support for ETC2 EAC R11 and ETC2 EAC RG11
#ifndef BASISD_SUPPORT_ETC2_EAC_RG11
	#define BASISD_SUPPORT_ETC2_EAC_RG11 1
#endif

// If BASISD_SUPPORT_ASTC_HIGHER_OPAQUE_QUALITY is 1, opaque blocks will be transcoded to ASTC at slightly higher quality (higher than BC1), but the transcoder tables will be 2x as large.
// This impacts grayscale and grayscale+alpha textures the most.
#ifndef BASISD_SUPPORT_ASTC_HIGHER_OPAQUE_QUALITY
	#ifdef __EMSCRIPTEN__
		// Let's assume size matters more than quality when compiling with emscripten.
		#define BASISD_SUPPORT_ASTC_HIGHER_OPAQUE_QUALITY 0
	#else
		// Compiling native, so an extra 64K lookup table is probably acceptable.
		#define BASISD_SUPPORT_ASTC_HIGHER_OPAQUE_QUALITY 1
	#endif
#endif

#ifndef BASISD_SUPPORT_FXT1
	#define BASISD_SUPPORT_FXT1 1
#endif

#ifndef BASISD_SUPPORT_PVRTC2
	#define BASISD_SUPPORT_PVRTC2 1
#endif

#if BASISD_SUPPORT_PVRTC2
	#if !BASISD_SUPPORT_ATC
		#error BASISD_SUPPORT_ATC must be 1 if BASISD_SUPPORT_PVRTC2 is 1
	#endif
#endif

#if BASISD_SUPPORT_ATC
	#if !BASISD_SUPPORT_DXT5A
		#error BASISD_SUPPORT_DXT5A must be 1 if BASISD_SUPPORT_ATC is 1
	#endif
#endif

#ifndef BASISD_SUPPORT_UASTC_HDR
	#define BASISD_SUPPORT_UASTC_HDR 1
#endif

#define BASISD_WRITE_NEW_BC7_MODE5_TABLES			0
#define BASISD_WRITE_NEW_DXT1_TABLES				0
#define BASISD_WRITE_NEW_ETC2_EAC_A8_TABLES			0
#define BASISD_WRITE_NEW_ASTC_TABLES				0
#define BASISD_WRITE_NEW_ATC_TABLES					0
#define BASISD_WRITE_NEW_ETC2_EAC_R11_TABLES		0

#ifndef BASISD_ENABLE_DEBUG_FLAGS
	#define BASISD_ENABLE_DEBUG_FLAGS	0
#endif

// If KTX2 support is enabled, we may need Zstd for decompression of supercompressed UASTC files. Include this header.
#if BASISD_SUPPORT_KTX2
   // If BASISD_SUPPORT_KTX2_ZSTD is 0, UASTC files compressed with Zstd cannot be loaded.
	#if BASISD_SUPPORT_KTX2_ZSTD
		// We only use two Zstd API's: ZSTD_decompress() and ZSTD_isError()
		#include <zstd.h>
	#endif
#endif

#if BASISD_SUPPORT_UASTC_HDR
using namespace basist::astc_6x6_hdr;
#endif

namespace basisu
{
	bool g_debug_printf;

	void enable_debug_printf(bool enabled)
	{
		g_debug_printf = enabled;
	}

	void debug_printf(const char* pFmt, ...)
	{
#if BASISU_FORCE_DEVEL_MESSAGES	
		g_debug_printf = true;
#endif
		if (g_debug_printf)
		{
			va_list args;
			va_start(args, pFmt);
			vprintf(pFmt, args);
			va_end(args);
		}
	}

	void debug_puts(const char* p)
	{
#if BASISU_FORCE_DEVEL_MESSAGES	
		g_debug_printf = true;
#endif
		if (g_debug_printf)
		{
			//puts(p);
			printf("%s", p);
		}
	}
} // namespace basisu

namespace basist
{
#if BASISD_ENABLE_DEBUG_FLAGS
	static uint32_t g_debug_flags = 0;
#endif

	uint32_t get_debug_flags()
	{
#if BASISD_ENABLE_DEBUG_FLAGS
		return g_debug_flags;
#else
		return 0;
#endif
	}

	void set_debug_flags(uint32_t f)
	{
		BASISU_NOTE_UNUSED(f);
#if BASISD_ENABLE_DEBUG_FLAGS
		g_debug_flags = f;
#endif
	}

	inline uint16_t byteswap_uint16(uint16_t v)
	{
		return static_cast<uint16_t>((v >> 8) | (v << 8));
	}

	static inline int32_t clampi(int32_t value, int32_t low, int32_t high) { if (value < low) value = low; else if (value > high) value = high;	return value; }
	static inline float clampf(float value, float low, float high) { if (value < low) value = low; else if (value > high) value = high;	return value; }
	static inline float saturate(float value) { return clampf(value, 0, 1.0f); }

	static inline uint8_t mul_8(uint32_t v, uint32_t q) { v = v * q + 128; return (uint8_t)((v + (v >> 8)) >> 8); }
	static inline int mul_8bit(int a, int b) { int t = a * b + 128; return (t + (t >> 8)) >> 8; }
	static inline int lerp_8bit(int a, int b, int s) { assert(a >= 0 && a <= 255); assert(b >= 0 && b <= 255); assert(s >= 0 && s <= 255); return a + mul_8bit(b - a, s); }

	struct vec2F
	{
		float c[2];

		inline vec2F() {}

		inline vec2F(float s) { c[0] = s; c[1] = s; }
		inline vec2F(float x, float y) { c[0] = x; c[1] = y; }

		inline void set(float x, float y) { c[0] = x; c[1] = y; }

		inline float dot(const vec2F& o) const { return (c[0] * o.c[0]) + (c[1] * o.c[1]); }

		inline float operator[] (uint32_t index) const { assert(index < 2); return c[index]; }
		inline float& operator[] (uint32_t index) { assert(index < 2); return c[index]; }

		inline vec2F& clamp(float l, float h)
		{
			c[0] = basisu::clamp(c[0], l, h);
			c[1] = basisu::clamp(c[1], l, h);
			return *this;
		}

		static vec2F lerp(const vec2F& a, const vec2F& b, float s)
		{
			vec2F res;
			for (uint32_t i = 0; i < 2; i++)
				res[i] = basisu::lerp(a[i], b[i], s);
			return res;
		}
	};

	struct vec3F
	{
		float c[3];

		inline vec3F() {}

		inline vec3F(float s) { c[0] = s; c[1] = s; c[2] = s; }
		inline vec3F(float x, float y, float z) { c[0] = x; c[1] = y; c[2] = z; }

		inline void set(float x, float y, float z) { c[0] = x; c[1] = y; c[2] = z; }

		inline float dot(const vec3F& o) const { return (c[0] * o.c[0]) + (c[1] * o.c[1]) + (c[2] * o.c[2]); }

		inline float operator[] (uint32_t index) const { assert(index < 3); return c[index]; }
		inline float &operator[] (uint32_t index) { assert(index < 3); return c[index]; }

		inline vec3F& clamp(float l, float h)
		{
			c[0] = basisu::clamp(c[0], l, h);
			c[1] = basisu::clamp(c[1], l, h);
			c[2] = basisu::clamp(c[2], l, h);
			return *this;
		}

		static vec3F lerp(const vec3F& a, const vec3F& b, float s)
		{
			vec3F res;
			for (uint32_t i = 0; i < 3; i++)
				res[i] = basisu::lerp(a[i], b[i], s);
			return res;
		}
	};

	uint16_t crc16(const void* r, size_t size, uint16_t crc)
	{
		crc = ~crc;

		const uint8_t* p = static_cast<const uint8_t*>(r);
		for (; size; --size)
		{
			const uint16_t q = *p++ ^ (crc >> 8);
			uint16_t k = (q >> 4) ^ q;
			crc = (((crc << 8) ^ k) ^ (k << 5)) ^ (k << 12);
		}

		return static_cast<uint16_t>(~crc);
	}

	struct vec4F
	{
		float c[4];

		inline void set(float x, float y, float z, float w) { c[0] = x; c[1] = y; c[2] = z; c[3] = w; }

		float operator[] (uint32_t index) const { assert(index < 4); return c[index]; }
		float& operator[] (uint32_t index) { assert(index < 4); return c[index]; }
	};
		
	enum etc_constants
	{
		cETC1BytesPerBlock = 8U,

		cETC1SelectorBits = 2U,
		cETC1SelectorValues = 1U << cETC1SelectorBits,
		cETC1SelectorMask = cETC1SelectorValues - 1U,

		cETC1BlockShift = 2U,
		cETC1BlockSize = 1U << cETC1BlockShift,

		cETC1LSBSelectorIndicesBitOffset = 0,
		cETC1MSBSelectorIndicesBitOffset = 16,

		cETC1FlipBitOffset = 32,
		cETC1DiffBitOffset = 33,

		cETC1IntenModifierNumBits = 3,
		cETC1IntenModifierValues = 1 << cETC1IntenModifierNumBits,
		cETC1RightIntenModifierTableBitOffset = 34,
		cETC1LeftIntenModifierTableBitOffset = 37,

		// Base+Delta encoding (5 bit bases, 3 bit delta)
		cETC1BaseColorCompNumBits = 5,
		cETC1BaseColorCompMax = 1 << cETC1BaseColorCompNumBits,

		cETC1DeltaColorCompNumBits = 3,
		cETC1DeltaColorComp = 1 << cETC1DeltaColorCompNumBits,
		cETC1DeltaColorCompMax = 1 << cETC1DeltaColorCompNumBits,

		cETC1BaseColor5RBitOffset = 59,
		cETC1BaseColor5GBitOffset = 51,
		cETC1BaseColor5BBitOffset = 43,

		cETC1DeltaColor3RBitOffset = 56,
		cETC1DeltaColor3GBitOffset = 48,
		cETC1DeltaColor3BBitOffset = 40,

		// Absolute (non-delta) encoding (two 4-bit per component bases)
		cETC1AbsColorCompNumBits = 4,
		cETC1AbsColorCompMax = 1 << cETC1AbsColorCompNumBits,

		cETC1AbsColor4R1BitOffset = 60,
		cETC1AbsColor4G1BitOffset = 52,
		cETC1AbsColor4B1BitOffset = 44,

		cETC1AbsColor4R2BitOffset = 56,
		cETC1AbsColor4G2BitOffset = 48,
		cETC1AbsColor4B2BitOffset = 40,

		cETC1ColorDeltaMin = -4,
		cETC1ColorDeltaMax = 3,

		// Delta3:
		// 0   1   2   3   4   5   6   7
		// 000 001 010 011 100 101 110 111
		// 0   1   2   3   -4  -3  -2  -1
	};

#define DECLARE_ETC1_INTEN_TABLE(name, N) \
	static const int name[cETC1IntenModifierValues][cETC1SelectorValues] = \
	{ \
		{ N * -8,  N * -2,   N * 2,   N * 8 },{ N * -17,  N * -5,  N * 5,  N * 17 },{ N * -29,  N * -9,   N * 9,  N * 29 },{ N * -42, N * -13, N * 13,  N * 42 }, \
		{ N * -60, N * -18, N * 18,  N * 60 },{ N * -80, N * -24, N * 24,  N * 80 },{ N * -106, N * -33, N * 33, N * 106 },{ N * -183, N * -47, N * 47, N * 183 } \
	};

	DECLARE_ETC1_INTEN_TABLE(g_etc1_inten_tables, 1);
	DECLARE_ETC1_INTEN_TABLE(g_etc1_inten_tables16, 16);
	DECLARE_ETC1_INTEN_TABLE(g_etc1_inten_tables48, 3 * 16);

	//const uint8_t g_etc1_to_selector_index[cETC1SelectorValues] = { 2, 3, 1, 0 };
	const uint8_t g_selector_index_to_etc1[cETC1SelectorValues] = { 3, 2, 0, 1 };
	
	static const uint8_t g_etc_5_to_8[32] = { 0, 8, 16, 24, 33, 41, 49, 57, 66, 74, 82, 90, 99, 107, 115, 123, 132, 140, 148, 156, 165, 173, 181, 189, 198, 206, 214, 222, 231, 239, 247, 255 };

	struct decoder_etc_block
	{
		// big endian uint64:
		// bit ofs:  56  48  40  32  24  16   8   0
		// byte ofs: b0, b1, b2, b3, b4, b5, b6, b7 
		union
		{
			uint64_t m_uint64;

			uint32_t m_uint32[2];

			uint8_t m_bytes[8];

			struct
			{
				signed m_dred2 : 3;
				uint32_t m_red1 : 5;

				signed m_dgreen2 : 3;
				uint32_t m_green1 : 5;

				signed m_dblue2 : 3;
				uint32_t m_blue1 : 5;

				uint32_t m_flip : 1;
				uint32_t m_diff : 1;
				uint32_t m_cw2 : 3;
				uint32_t m_cw1 : 3;

				uint32_t m_selectors;
			} m_differential;
		};

		inline void clear()
		{
			assert(sizeof(*this) == 8);
			basisu::clear_obj(*this);
		}

		inline void set_byte_bits(uint32_t ofs, uint32_t num, uint32_t bits)
		{
			assert((ofs + num) <= 64U);
			assert(num && (num < 32U));
			assert((ofs >> 3) == ((ofs + num - 1) >> 3));
			assert(bits < (1U << num));
			const uint32_t byte_ofs = 7 - (ofs >> 3);
			const uint32_t byte_bit_ofs = ofs & 7;
			const uint32_t mask = (1 << num) - 1;
			m_bytes[byte_ofs] &= ~(mask << byte_bit_ofs);
			m_bytes[byte_ofs] |= (bits << byte_bit_ofs);
		}

		inline void set_flip_bit(bool flip)
		{
			m_bytes[3] &= ~1;
			m_bytes[3] |= static_cast<uint8_t>(flip);
		}

		inline void set_diff_bit(bool diff)
		{
			m_bytes[3] &= ~2;
			m_bytes[3] |= (static_cast<uint32_t>(diff) << 1);
		}

		// Sets intensity modifier table (0-7) used by subblock subblock_id (0 or 1)
		inline void set_inten_table(uint32_t subblock_id, uint32_t t)
		{
			assert(subblock_id < 2);
			assert(t < 8);
			const uint32_t ofs = subblock_id ? 2 : 5;
			m_bytes[3] &= ~(7 << ofs);
			m_bytes[3] |= (t << ofs);
		}

		// Selector "val" ranges from 0-3 and is a direct index into g_etc1_inten_tables.
		inline void set_selector(uint32_t x, uint32_t y, uint32_t val)
		{
			assert((x | y | val) < 4);
			const uint32_t bit_index = x * 4 + y;

			uint8_t* p = &m_bytes[7 - (bit_index >> 3)];

			const uint32_t byte_bit_ofs = bit_index & 7;
			const uint32_t mask = 1 << byte_bit_ofs;

			static const uint8_t s_selector_index_to_etc1[4] = { 3, 2, 0, 1 };
			const uint32_t etc1_val = s_selector_index_to_etc1[val];

			const uint32_t lsb = etc1_val & 1;
			const uint32_t msb = etc1_val >> 1;

			p[0] &= ~mask;
			p[0] |= (lsb << byte_bit_ofs);

			p[-2] &= ~mask;
			p[-2] |= (msb << byte_bit_ofs);
		}

		// Returned encoded selector value ranges from 0-3 (this is NOT a direct index into g_etc1_inten_tables, see get_selector())
		inline uint32_t get_raw_selector(uint32_t x, uint32_t y) const
		{
			assert((x | y) < 4);

			const uint32_t bit_index = x * 4 + y;
			const uint32_t byte_bit_ofs = bit_index & 7;
			const uint8_t* p = &m_bytes[7 - (bit_index >> 3)];
			const uint32_t lsb = (p[0] >> byte_bit_ofs) & 1;
			const uint32_t msb = (p[-2] >> byte_bit_ofs) & 1;
			const uint32_t val = lsb | (msb << 1);

			return val;
		}

		// Returned selector value ranges from 0-3 and is a direct index into g_etc1_inten_tables.
		inline uint32_t get_selector(uint32_t x, uint32_t y) const
		{
			static const uint8_t s_etc1_to_selector_index[cETC1SelectorValues] = { 2, 3, 1, 0 };
			return s_etc1_to_selector_index[get_raw_selector(x, y)];
		}

		inline void set_raw_selector_bits(uint32_t bits)
		{
			m_bytes[4] = static_cast<uint8_t>(bits);
			m_bytes[5] = static_cast<uint8_t>(bits >> 8);
			m_bytes[6] = static_cast<uint8_t>(bits >> 16);
			m_bytes[7] = static_cast<uint8_t>(bits >> 24);
		}

		inline bool are_all_selectors_the_same() const
		{
			uint32_t v = *reinterpret_cast<const uint32_t*>(&m_bytes[4]);

			if ((v == 0xFFFFFFFF) || (v == 0xFFFF) || (!v) || (v == 0xFFFF0000))
				return true;

			return false;
		}

		inline void set_raw_selector_bits(uint8_t byte0, uint8_t byte1, uint8_t byte2, uint8_t byte3)
		{
			m_bytes[4] = byte0;
			m_bytes[5] = byte1;
			m_bytes[6] = byte2;
			m_bytes[7] = byte3;
		}

		inline uint32_t get_raw_selector_bits() const
		{
			return m_bytes[4] | (m_bytes[5] << 8) | (m_bytes[6] << 16) | (m_bytes[7] << 24);
		}

		inline void set_base4_color(uint32_t idx, uint16_t c)
		{
			if (idx)
			{
				set_byte_bits(cETC1AbsColor4R2BitOffset, 4, (c >> 8) & 15);
				set_byte_bits(cETC1AbsColor4G2BitOffset, 4, (c >> 4) & 15);
				set_byte_bits(cETC1AbsColor4B2BitOffset, 4, c & 15);
			}
			else
			{
				set_byte_bits(cETC1AbsColor4R1BitOffset, 4, (c >> 8) & 15);
				set_byte_bits(cETC1AbsColor4G1BitOffset, 4, (c >> 4) & 15);
				set_byte_bits(cETC1AbsColor4B1BitOffset, 4, c & 15);
			}
		}

		inline void set_base5_color(uint16_t c)
		{
			set_byte_bits(cETC1BaseColor5RBitOffset, 5, (c >> 10) & 31);
			set_byte_bits(cETC1BaseColor5GBitOffset, 5, (c >> 5) & 31);
			set_byte_bits(cETC1BaseColor5BBitOffset, 5, c & 31);
		}

		void set_delta3_color(uint16_t c)
		{
			set_byte_bits(cETC1DeltaColor3RBitOffset, 3, (c >> 6) & 7);
			set_byte_bits(cETC1DeltaColor3GBitOffset, 3, (c >> 3) & 7);
			set_byte_bits(cETC1DeltaColor3BBitOffset, 3, c & 7);
		}

		void set_block_color4(const color32& c0_unscaled, const color32& c1_unscaled)
		{
			set_diff_bit(false);

			set_base4_color(0, pack_color4(c0_unscaled, false));
			set_base4_color(1, pack_color4(c1_unscaled, false));
		}

		void set_block_color5(const color32& c0_unscaled, const color32& c1_unscaled)
		{
			set_diff_bit(true);

			set_base5_color(pack_color5(c0_unscaled, false));

			int dr = c1_unscaled.r - c0_unscaled.r;
			int dg = c1_unscaled.g - c0_unscaled.g;
			int db = c1_unscaled.b - c0_unscaled.b;

			set_delta3_color(pack_delta3(dr, dg, db));
		}

		bool set_block_color5_check(const color32& c0_unscaled, const color32& c1_unscaled)
		{
			set_diff_bit(true);

			set_base5_color(pack_color5(c0_unscaled, false));

			int dr = c1_unscaled.r - c0_unscaled.r;
			int dg = c1_unscaled.g - c0_unscaled.g;
			int db = c1_unscaled.b - c0_unscaled.b;

			if (((dr < cETC1ColorDeltaMin) || (dr > cETC1ColorDeltaMax)) ||
				((dg < cETC1ColorDeltaMin) || (dg > cETC1ColorDeltaMax)) ||
				((db < cETC1ColorDeltaMin) || (db > cETC1ColorDeltaMax)))
				return false;

			set_delta3_color(pack_delta3(dr, dg, db));

			return true;
		}

		inline uint32_t get_byte_bits(uint32_t ofs, uint32_t num) const
		{
			assert((ofs + num) <= 64U);
			assert(num && (num <= 8U));
			assert((ofs >> 3) == ((ofs + num - 1) >> 3));
			const uint32_t byte_ofs = 7 - (ofs >> 3);
			const uint32_t byte_bit_ofs = ofs & 7;
			return (m_bytes[byte_ofs] >> byte_bit_ofs) & ((1 << num) - 1);
		}

		inline uint16_t get_base5_color() const
		{
			const uint32_t r = get_byte_bits(cETC1BaseColor5RBitOffset, 5);
			const uint32_t g = get_byte_bits(cETC1BaseColor5GBitOffset, 5);
			const uint32_t b = get_byte_bits(cETC1BaseColor5BBitOffset, 5);
			return static_cast<uint16_t>(b | (g << 5U) | (r << 10U));
		}

		inline uint16_t get_base4_color(uint32_t idx) const
		{
			uint32_t r, g, b;
			if (idx)
			{
				r = get_byte_bits(cETC1AbsColor4R2BitOffset, 4);
				g = get_byte_bits(cETC1AbsColor4G2BitOffset, 4);
				b = get_byte_bits(cETC1AbsColor4B2BitOffset, 4);
			}
			else
			{
				r = get_byte_bits(cETC1AbsColor4R1BitOffset, 4);
				g = get_byte_bits(cETC1AbsColor4G1BitOffset, 4);
				b = get_byte_bits(cETC1AbsColor4B1BitOffset, 4);
			}
			return static_cast<uint16_t>(b | (g << 4U) | (r << 8U));
		}

		inline color32 get_base5_color_unscaled() const
		{
			return color32(m_differential.m_red1, m_differential.m_green1, m_differential.m_blue1, 255);
		}

		inline bool get_flip_bit() const
		{
			return (m_bytes[3] & 1) != 0;
		}

		inline bool get_diff_bit() const
		{
			return (m_bytes[3] & 2) != 0;
		}
				
		inline uint32_t get_inten_table(uint32_t subblock_id) const
		{
			assert(subblock_id < 2);
			const uint32_t ofs = subblock_id ? 2 : 5;
			return (m_bytes[3] >> ofs) & 7;
		}

		inline uint16_t get_delta3_color() const
		{
			const uint32_t r = get_byte_bits(cETC1DeltaColor3RBitOffset, 3);
			const uint32_t g = get_byte_bits(cETC1DeltaColor3GBitOffset, 3);
			const uint32_t b = get_byte_bits(cETC1DeltaColor3BBitOffset, 3);
			return static_cast<uint16_t>(b | (g << 3U) | (r << 6U));
		}
		
		void get_block_colors(color32* pBlock_colors, uint32_t subblock_index) const
		{
			color32 b;

			if (get_diff_bit())
			{
				if (subblock_index)
					unpack_color5(b, get_base5_color(), get_delta3_color(), true, 255);
				else
					unpack_color5(b, get_base5_color(), true);
			}
			else
			{
				b = unpack_color4(get_base4_color(subblock_index), true, 255);
			}

			const int* pInten_table = g_etc1_inten_tables[get_inten_table(subblock_index)];

			pBlock_colors[0].set_noclamp_rgba(clamp255(b.r + pInten_table[0]), clamp255(b.g + pInten_table[0]), clamp255(b.b + pInten_table[0]), 255);
			pBlock_colors[1].set_noclamp_rgba(clamp255(b.r + pInten_table[1]), clamp255(b.g + pInten_table[1]), clamp255(b.b + pInten_table[1]), 255);
			pBlock_colors[2].set_noclamp_rgba(clamp255(b.r + pInten_table[2]), clamp255(b.g + pInten_table[2]), clamp255(b.b + pInten_table[2]), 255);
			pBlock_colors[3].set_noclamp_rgba(clamp255(b.r + pInten_table[3]), clamp255(b.g + pInten_table[3]), clamp255(b.b + pInten_table[3]), 255);
		}

		static uint16_t pack_color4(const color32& color, bool scaled, uint32_t bias = 127U)
		{
			return pack_color4(color.r, color.g, color.b, scaled, bias);
		}

		static uint16_t pack_color4(uint32_t r, uint32_t g, uint32_t b, bool scaled, uint32_t bias = 127U)
		{
			if (scaled)
			{
				r = (r * 15U + bias) / 255U;
				g = (g * 15U + bias) / 255U;
				b = (b * 15U + bias) / 255U;
			}

			r = basisu::minimum(r, 15U);
			g = basisu::minimum(g, 15U);
			b = basisu::minimum(b, 15U);

			return static_cast<uint16_t>(b | (g << 4U) | (r << 8U));
		}

		static uint16_t pack_color5(const color32& color, bool scaled, uint32_t bias = 127U)
		{
			return pack_color5(color.r, color.g, color.b, scaled, bias);
		}

		static uint16_t pack_color5(uint32_t r, uint32_t g, uint32_t b, bool scaled, uint32_t bias = 127U)
		{
			if (scaled)
			{
				r = (r * 31U + bias) / 255U;
				g = (g * 31U + bias) / 255U;
				b = (b * 31U + bias) / 255U;
			}

			r = basisu::minimum(r, 31U);
			g = basisu::minimum(g, 31U);
			b = basisu::minimum(b, 31U);

			return static_cast<uint16_t>(b | (g << 5U) | (r << 10U));
		}

		uint16_t pack_delta3(const color32& color)
		{
			return pack_delta3(color.r, color.g, color.b);
		}

		uint16_t pack_delta3(int r, int g, int b)
		{
			assert((r >= cETC1ColorDeltaMin) && (r <= cETC1ColorDeltaMax));
			assert((g >= cETC1ColorDeltaMin) && (g <= cETC1ColorDeltaMax));
			assert((b >= cETC1ColorDeltaMin) && (b <= cETC1ColorDeltaMax));
			if (r < 0) r += 8;
			if (g < 0) g += 8;
			if (b < 0) b += 8;
			return static_cast<uint16_t>(b | (g << 3) | (r << 6));
		}

		static void unpack_delta3(int& r, int& g, int& b, uint16_t packed_delta3)
		{
			r = (packed_delta3 >> 6) & 7;
			g = (packed_delta3 >> 3) & 7;
			b = packed_delta3 & 7;
			if (r >= 4) r -= 8;
			if (g >= 4) g -= 8;
			if (b >= 4) b -= 8;
		}

		static color32 unpack_color5(uint16_t packed_color5, bool scaled, uint32_t alpha)
		{
			uint32_t b = packed_color5 & 31U;
			uint32_t g = (packed_color5 >> 5U) & 31U;
			uint32_t r = (packed_color5 >> 10U) & 31U;

			if (scaled)
			{
				b = (b << 3U) | (b >> 2U);
				g = (g << 3U) | (g >> 2U);
				r = (r << 3U) | (r >> 2U);
			}

			assert(alpha <= 255);

			return color32(cNoClamp, r, g, b, alpha);
		}

		static void unpack_color5(uint32_t& r, uint32_t& g, uint32_t& b, uint16_t packed_color5, bool scaled)
		{
			color32 c(unpack_color5(packed_color5, scaled, 0));
			r = c.r;
			g = c.g;
			b = c.b;
		}
				
		static void unpack_color5(color32& result, uint16_t packed_color5, bool scaled)
		{
			result = unpack_color5(packed_color5, scaled, 255);
		}

		static bool unpack_color5(color32& result, uint16_t packed_color5, uint16_t packed_delta3, bool scaled, uint32_t alpha)
		{
			int dr, dg, db;
			unpack_delta3(dr, dg, db, packed_delta3);

			int r = ((packed_color5 >> 10U) & 31U) + dr;
			int g = ((packed_color5 >> 5U) & 31U) + dg;
			int b = (packed_color5 & 31U) + db;

			bool success = true;
			if (static_cast<uint32_t>(r | g | b) > 31U)
			{
				success = false;
				r = basisu::clamp<int>(r, 0, 31);
				g = basisu::clamp<int>(g, 0, 31);
				b = basisu::clamp<int>(b, 0, 31);
			}

			if (scaled)
			{
				b = (b << 3U) | (b >> 2U);
				g = (g << 3U) | (g >> 2U);
				r = (r << 3U) | (r >> 2U);
			}

			result.set_noclamp_rgba(r, g, b, basisu::minimum(alpha, 255U));
			return success;
		}

		static color32 unpack_color4(uint16_t packed_color4, bool scaled, uint32_t alpha)
		{
			uint32_t b = packed_color4 & 15U;
			uint32_t g = (packed_color4 >> 4U) & 15U;
			uint32_t r = (packed_color4 >> 8U) & 15U;

			if (scaled)
			{
				b = (b << 4U) | b;
				g = (g << 4U) | g;
				r = (r << 4U) | r;
			}

			return color32(cNoClamp, r, g, b, basisu::minimum(alpha, 255U));
		}

		static void unpack_color4(uint32_t& r, uint32_t& g, uint32_t& b, uint16_t packed_color4, bool scaled)
		{
			color32 c(unpack_color4(packed_color4, scaled, 0));
			r = c.r;
			g = c.g;
			b = c.b;
		}

		static void get_diff_subblock_colors(color32* pDst, uint16_t packed_color5, uint32_t table_idx)
		{
			assert(table_idx < cETC1IntenModifierValues);
			const int* pInten_modifer_table = &g_etc1_inten_tables[table_idx][0];

			uint32_t r, g, b;
			unpack_color5(r, g, b, packed_color5, true);

			const int ir = static_cast<int>(r), ig = static_cast<int>(g), ib = static_cast<int>(b);

			const int y0 = pInten_modifer_table[0];
			pDst[0].set(clamp255(ir + y0), clamp255(ig + y0), clamp255(ib + y0), 255);

			const int y1 = pInten_modifer_table[1];
			pDst[1].set(clamp255(ir + y1), clamp255(ig + y1), clamp255(ib + y1), 255);

			const int y2 = pInten_modifer_table[2];
			pDst[2].set(clamp255(ir + y2), clamp255(ig + y2), clamp255(ib + y2), 255);

			const int y3 = pInten_modifer_table[3];
			pDst[3].set(clamp255(ir + y3), clamp255(ig + y3), clamp255(ib + y3), 255);
		}

		static int clamp255(int x)
		{
			if (x & 0xFFFFFF00)
			{
				if (x < 0)
					x = 0;
				else if (x > 255)
					x = 255;
			}

			return x;
		}

		static void get_block_colors5(color32* pBlock_colors, const color32& base_color5, uint32_t inten_table)
		{
			color32 b(base_color5);

			b.r = (b.r << 3) | (b.r >> 2);
			b.g = (b.g << 3) | (b.g >> 2);
			b.b = (b.b << 3) | (b.b >> 2);

			const int* pInten_table = g_etc1_inten_tables[inten_table];

			pBlock_colors[0].set(clamp255(b.r + pInten_table[0]), clamp255(b.g + pInten_table[0]), clamp255(b.b + pInten_table[0]), 255);
			pBlock_colors[1].set(clamp255(b.r + pInten_table[1]), clamp255(b.g + pInten_table[1]), clamp255(b.b + pInten_table[1]), 255);
			pBlock_colors[2].set(clamp255(b.r + pInten_table[2]), clamp255(b.g + pInten_table[2]), clamp255(b.b + pInten_table[2]), 255);
			pBlock_colors[3].set(clamp255(b.r + pInten_table[3]), clamp255(b.g + pInten_table[3]), clamp255(b.b + pInten_table[3]), 255);
		}

		static void get_block_color5(const color32& base_color5, uint32_t inten_table, uint32_t index, uint32_t& r, uint32_t &g, uint32_t &b)
		{
			assert(index < 4);

			uint32_t br = (base_color5.r << 3) | (base_color5.r >> 2);
			uint32_t bg = (base_color5.g << 3) | (base_color5.g >> 2);
			uint32_t bb = (base_color5.b << 3) | (base_color5.b >> 2);

			const int* pInten_table = g_etc1_inten_tables[inten_table];

			r = clamp255(br + pInten_table[index]);
			g = clamp255(bg + pInten_table[index]);
			b = clamp255(bb + pInten_table[index]);
		}

		static void get_block_color5_r(const color32& base_color5, uint32_t inten_table, uint32_t index, uint32_t &r)
		{
			assert(index < 4);
						
			uint32_t br = (base_color5.r << 3) | (base_color5.r >> 2);

			const int* pInten_table = g_etc1_inten_tables[inten_table];

			r = clamp255(br + pInten_table[index]);
		}

		static void get_block_colors5_g(int* pBlock_colors, const color32& base_color5, uint32_t inten_table)
		{
			const int g = (base_color5.g << 3) | (base_color5.g >> 2);

			const int* pInten_table = g_etc1_inten_tables[inten_table];

			pBlock_colors[0] = clamp255(g + pInten_table[0]);
			pBlock_colors[1] = clamp255(g + pInten_table[1]);
			pBlock_colors[2] = clamp255(g + pInten_table[2]);
			pBlock_colors[3] = clamp255(g + pInten_table[3]);
		}

		static void get_block_colors5_bounds(color32* pBlock_colors, const color32& base_color5, uint32_t inten_table, uint32_t l = 0, uint32_t h = 3)
		{
			color32 b(base_color5);

			b.r = (b.r << 3) | (b.r >> 2);
			b.g = (b.g << 3) | (b.g >> 2);
			b.b = (b.b << 3) | (b.b >> 2);

			const int* pInten_table = g_etc1_inten_tables[inten_table];

			pBlock_colors[0].set(clamp255(b.r + pInten_table[l]), clamp255(b.g + pInten_table[l]), clamp255(b.b + pInten_table[l]), 255);
			pBlock_colors[1].set(clamp255(b.r + pInten_table[h]), clamp255(b.g + pInten_table[h]), clamp255(b.b + pInten_table[h]), 255);
		}

		static void get_block_colors5_bounds_g(uint32_t* pBlock_colors, const color32& base_color5, uint32_t inten_table, uint32_t l = 0, uint32_t h = 3)
		{
			color32 b(base_color5);

			b.g = (b.g << 3) | (b.g >> 2);

			const int* pInten_table = g_etc1_inten_tables[inten_table];

			pBlock_colors[0] = clamp255(b.g + pInten_table[l]);
			pBlock_colors[1] = clamp255(b.g + pInten_table[h]);
		}
	};

	enum dxt_constants
	{
		cDXT1SelectorBits = 2U, cDXT1SelectorValues = 1U << cDXT1SelectorBits, cDXT1SelectorMask = cDXT1SelectorValues - 1U,
		cDXT5SelectorBits = 3U, cDXT5SelectorValues = 1U << cDXT5SelectorBits, cDXT5SelectorMask = cDXT5SelectorValues - 1U,
	};

	static const uint8_t g_etc1_x_selector_unpack[4][256] =
	{
		{
			0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
			0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
			0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
			0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
			0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
			0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
			0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
			0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
		},
		{
			0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1,
			2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3,
			0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1,
			2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3,
			0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1,
			2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3,
			0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1,
			2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3,
		},

		{
			0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1,
			0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1,
			2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3,
			2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3,
			0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1,
			0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1,
			2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3,
			2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3,
		},

		{
			0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1,
			0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1,
			0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1,
			0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1,
			2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3,
			2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3,
			2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3,
			2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3,
		}
	};

	struct dxt1_block
	{
		enum { cTotalEndpointBytes = 2, cTotalSelectorBytes = 4 };

		uint8_t m_low_color[cTotalEndpointBytes];
		uint8_t m_high_color[cTotalEndpointBytes];
		uint8_t m_selectors[cTotalSelectorBytes];

		inline void clear() { basisu::clear_obj(*this); }

		inline uint32_t get_high_color() const { return m_high_color[0] | (m_high_color[1] << 8U); }
		inline uint32_t get_low_color() const { return m_low_color[0] | (m_low_color[1] << 8U); }
		inline void set_low_color(uint16_t c) { m_low_color[0] = static_cast<uint8_t>(c & 0xFF); m_low_color[1] = static_cast<uint8_t>((c >> 8) & 0xFF); }
		inline void set_high_color(uint16_t c) { m_high_color[0] = static_cast<uint8_t>(c & 0xFF); m_high_color[1] = static_cast<uint8_t>((c >> 8) & 0xFF); }
		inline uint32_t get_selector(uint32_t x, uint32_t y) const { assert((x < 4U) && (y < 4U)); return (m_selectors[y] >> (x * cDXT1SelectorBits)) & cDXT1SelectorMask; }
		inline void set_selector(uint32_t x, uint32_t y, uint32_t val) { assert((x < 4U) && (y < 4U) && (val < 4U)); m_selectors[y] &= (~(cDXT1SelectorMask << (x * cDXT1SelectorBits))); m_selectors[y] |= (val << (x * cDXT1SelectorBits)); }

		static uint16_t pack_color(const color32& color, bool scaled, uint32_t bias = 127U)
		{
			uint32_t r = color.r, g = color.g, b = color.b;
			if (scaled)
			{
				r = (r * 31U + bias) / 255U;
				g = (g * 63U + bias) / 255U;
				b = (b * 31U + bias) / 255U;
			}
			return static_cast<uint16_t>(basisu::minimum(b, 31U) | (basisu::minimum(g, 63U) << 5U) | (basisu::minimum(r, 31U) << 11U));
		}

		static uint16_t pack_unscaled_color(uint32_t r, uint32_t g, uint32_t b) { return static_cast<uint16_t>(b | (g << 5U) | (r << 11U)); }
	};

	struct dxt_selector_range
	{
		uint32_t m_low;
		uint32_t m_high;
	};

	struct etc1_to_dxt1_56_solution
	{
		uint8_t m_lo;
		uint8_t m_hi;
		uint16_t m_err;
	};

#if BASISD_SUPPORT_DXT1
	static dxt_selector_range g_etc1_to_dxt1_selector_ranges[] =
	{
		{ 0, 3 },

		{ 1, 3 },
		{ 0, 2 },

		{ 1, 2 },

		{ 2, 3 },
		{ 0, 1 },
	};

	const uint32_t NUM_ETC1_TO_DXT1_SELECTOR_RANGES = sizeof(g_etc1_to_dxt1_selector_ranges) / sizeof(g_etc1_to_dxt1_selector_ranges[0]);

	static uint32_t g_etc1_to_dxt1_selector_range_index[4][4];

	const uint32_t NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS = 10;
	static const uint8_t g_etc1_to_dxt1_selector_mappings[NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS][4] =
	{
		{ 0, 0, 1, 1 },
		{ 0, 0, 1, 2 },
		{ 0, 0, 1, 3 },
		{ 0, 0, 2, 3 },
		{ 0, 1, 1, 1 },
		{ 0, 1, 2, 2 },
		{ 0, 1, 2, 3 },
		{ 0, 2, 3, 3 },
		{ 1, 2, 2, 2 },
		{ 1, 2, 3, 3 },
	};
	
	static uint8_t g_etc1_to_dxt1_selector_mappings_raw_dxt1_256[NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS][256];
	static uint8_t g_etc1_to_dxt1_selector_mappings_raw_dxt1_inv_256[NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS][256];

	static const etc1_to_dxt1_56_solution g_etc1_to_dxt_6[32 * 8 * NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS * NUM_ETC1_TO_DXT1_SELECTOR_RANGES] = {
#include "basisu_transcoder_tables_dxt1_6.inc"
	};

	static const etc1_to_dxt1_56_solution g_etc1_to_dxt_5[32 * 8 * NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS * NUM_ETC1_TO_DXT1_SELECTOR_RANGES] = {
#include "basisu_transcoder_tables_dxt1_5.inc"
	};
#endif // BASISD_SUPPORT_DXT1

#if BASISD_SUPPORT_DXT1 || BASISD_SUPPORT_UASTC
	// First saw the idea for optimal BC1 single-color block encoding using lookup tables in ryg_dxt.
	struct bc1_match_entry
	{
		uint8_t m_hi;
		uint8_t m_lo;
	};
	static bc1_match_entry g_bc1_match5_equals_1[256], g_bc1_match6_equals_1[256]; // selector 1, allow equals hi/lo
	static bc1_match_entry g_bc1_match5_equals_0[256], g_bc1_match6_equals_0[256]; // selector 0, allow equals hi/lo

	static void prepare_bc1_single_color_table(bc1_match_entry* pTable, const uint8_t* pExpand, int size0, int size1, int sel)
	{
		for (int i = 0; i < 256; i++)
		{
			int lowest_e = 256;
			for (int lo = 0; lo < size0; lo++)
			{
				for (int hi = 0; hi < size1; hi++)
				{
					const int lo_e = pExpand[lo], hi_e = pExpand[hi];
					int e;

					if (sel == 1)
					{
						// Selector 1
						e = basisu::iabs(((hi_e * 2 + lo_e) / 3) - i);
						e += (basisu::iabs(hi_e - lo_e) * 3) / 100;
					}
					else
					{
						assert(sel == 0);

						// Selector 0
						e = basisu::iabs(hi_e - i);
					}

					if (e < lowest_e)
					{
						pTable[i].m_hi = static_cast<uint8_t>(hi);
						pTable[i].m_lo = static_cast<uint8_t>(lo);

						lowest_e = e;
					}

				} // hi
			} // lo
		}
	}
#endif

#if BASISD_WRITE_NEW_DXT1_TABLES
	static void create_etc1_to_dxt1_5_conversion_table()
	{
		FILE* pFile = nullptr;
		fopen_s(&pFile, "basisu_transcoder_tables_dxt1_5.inc", "w");

		uint32_t n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1_TO_DXT1_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1_to_dxt1_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1_to_dxt1_selector_ranges[sr].m_high;

					for (uint32_t m = 0; m < NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS; m++)
					{
						uint32_t best_lo = 0;
						uint32_t best_hi = 0;
						uint64_t best_err = UINT64_MAX;

						for (uint32_t hi = 0; hi <= 31; hi++)
						{
							for (uint32_t lo = 0; lo <= 31; lo++)
							{
								//if (lo == hi) continue;

								uint32_t colors[4];

								colors[0] = (lo << 3) | (lo >> 2);
								colors[3] = (hi << 3) | (hi >> 2);

								colors[1] = (colors[0] * 2 + colors[3]) / 3;
								colors[2] = (colors[3] * 2 + colors[0]) / 3;

								uint64_t total_err = 0;

								for (uint32_t s = low_selector; s <= high_selector; s++)
								{
									int err = block_colors[s].g - colors[g_etc1_to_dxt1_selector_mappings[m][s]];

									total_err += err * err;
								}

								if (total_err < best_err)
								{
									best_err = total_err;
									best_lo = lo;
									best_hi = hi;
								}
							}
						}

						assert(best_err <= 0xFFFF);

						//table[g + inten * 32].m_solutions[sr][m].m_lo = static_cast<uint8_t>(best_lo);
						//table[g + inten * 32].m_solutions[sr][m].m_hi = static_cast<uint8_t>(best_hi);
						//table[g + inten * 32].m_solutions[sr][m].m_err = static_cast<uint16_t>(best_err);

						//assert(best_lo != best_hi);
						fprintf(pFile, "{%u,%u,%u},", best_lo, best_hi, (uint32_t)best_err);
						n++;
						if ((n & 31) == 31)
							fprintf(pFile, "\n");
					} // m
				} // sr
			} // g
		} // inten

		fclose(pFile);
	}

	static void create_etc1_to_dxt1_6_conversion_table()
	{
		FILE* pFile = nullptr;
		fopen_s(&pFile, "basisu_transcoder_tables_dxt1_6.inc", "w");

		uint32_t n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1_TO_DXT1_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1_to_dxt1_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1_to_dxt1_selector_ranges[sr].m_high;

					for (uint32_t m = 0; m < NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS; m++)
					{
						uint32_t best_lo = 0;
						uint32_t best_hi = 0;
						uint64_t best_err = UINT64_MAX;

						for (uint32_t hi = 0; hi <= 63; hi++)
						{
							for (uint32_t lo = 0; lo <= 63; lo++)
							{
								//if (lo == hi) continue;

								uint32_t colors[4];

								colors[0] = (lo << 2) | (lo >> 4);
								colors[3] = (hi << 2) | (hi >> 4);

								colors[1] = (colors[0] * 2 + colors[3]) / 3;
								colors[2] = (colors[3] * 2 + colors[0]) / 3;

								uint64_t total_err = 0;

								for (uint32_t s = low_selector; s <= high_selector; s++)
								{
									int err = block_colors[s].g - colors[g_etc1_to_dxt1_selector_mappings[m][s]];

									total_err += err * err;
								}

								if (total_err < best_err)
								{
									best_err = total_err;
									best_lo = lo;
									best_hi = hi;
								}
							}
						}

						assert(best_err <= 0xFFFF);

						//table[g + inten * 32].m_solutions[sr][m].m_lo = static_cast<uint8_t>(best_lo);
						//table[g + inten * 32].m_solutions[sr][m].m_hi = static_cast<uint8_t>(best_hi);
						//table[g + inten * 32].m_solutions[sr][m].m_err = static_cast<uint16_t>(best_err);

						//assert(best_lo != best_hi);
						fprintf(pFile, "{%u,%u,%u},", best_lo, best_hi, (uint32_t)best_err);
						n++;
						if ((n & 31) == 31)
							fprintf(pFile, "\n");

					} // m
				} // sr
			} // g
		} // inten

		fclose(pFile);
	}
#endif

#if BASISD_SUPPORT_UASTC || BASISD_SUPPORT_ETC2_EAC_A8 || BASISD_SUPPORT_ETC2_EAC_RG11
	static const int8_t g_eac_modifier_table[16][8] =
	{
		{ -3, -6, -9, -15, 2, 5, 8, 14 },
		{ -3, -7, -10, -13, 2, 6, 9, 12 },
		{ -2, -5, -8, -13, 1, 4, 7, 12 },
		{ -2, -4, -6, -13, 1, 3, 5, 12 },
		{ -3, -6, -8, -12, 2, 5, 7, 11 },
		{ -3, -7, -9, -11, 2, 6, 8, 10 },
		{ -4, -7, -8, -11, 3, 6, 7, 10 },
		{ -3, -5, -8, -11, 2, 4, 7, 10 },

		{ -2, -6, -8, -10, 1, 5, 7, 9 },
		{ -2, -5, -8, -10, 1, 4, 7, 9 },
		{ -2, -4, -8, -10, 1, 3, 7, 9 },
		{ -2, -5, -7, -10, 1, 4, 6, 9 },
		{ -3, -4, -7, -10, 2, 3, 6, 9 },
		{ -1, -2, -3, -10, 0, 1, 2, 9 }, // entry 13
		{ -4, -6, -8, -9, 3, 5, 7, 8 },
		{ -3, -5, -7, -9, 2, 4, 6, 8 }
	};

	// Used by ETC2 EAC A8 and ETC2 EAC R11/RG11.
	struct eac_block
	{
		uint16_t m_base : 8;

		uint16_t m_table : 4;
		uint16_t m_multiplier : 4;

		uint8_t m_selectors[6];

		uint32_t get_selector(uint32_t x, uint32_t y) const
		{
			assert((x < 4) && (y < 4));

			const uint32_t ofs = 45 - (y + x * 4) * 3;

			const uint64_t pixels = get_selector_bits();

			return (pixels >> ofs) & 7;
		}

		void set_selector(uint32_t x, uint32_t y, uint32_t s)
		{
			assert((x < 4) && (y < 4) && (s < 8));

			const uint32_t ofs = 45 - (y + x * 4) * 3;

			uint64_t pixels = get_selector_bits();

			pixels &= ~(7ULL << ofs);
			pixels |= (static_cast<uint64_t>(s) << ofs);

			set_selector_bits(pixels);
		}

		uint64_t get_selector_bits() const
		{
			uint64_t pixels = ((uint64_t)m_selectors[0] << 40) | ((uint64_t)m_selectors[1] << 32) |
				((uint64_t)m_selectors[2] << 24) |
				((uint64_t)m_selectors[3] << 16) | ((uint64_t)m_selectors[4] << 8) | m_selectors[5];
			return pixels;
		}

		void set_selector_bits(uint64_t pixels)
		{
			m_selectors[0] = (uint8_t)(pixels >> 40);
			m_selectors[1] = (uint8_t)(pixels >> 32);
			m_selectors[2] = (uint8_t)(pixels >> 24);
			m_selectors[3] = (uint8_t)(pixels >> 16);
			m_selectors[4] = (uint8_t)(pixels >> 8);
			m_selectors[5] = (uint8_t)(pixels);
		}
	};

#endif // #if BASISD_SUPPORT_UASTC BASISD_SUPPORT_ETC2_EAC_A8 || BASISD_SUPPORT_ETC2_EAC_RG11

#if BASISD_SUPPORT_ETC2_EAC_A8 || BASISD_SUPPORT_ETC2_EAC_RG11
	static const dxt_selector_range s_etc2_eac_selector_ranges[] =
	{
		{ 0, 3 },

		{ 1, 3 },
		{ 0, 2 },

		{ 1, 2 },
	};

	const uint32_t NUM_ETC2_EAC_SELECTOR_RANGES = sizeof(s_etc2_eac_selector_ranges) / sizeof(s_etc2_eac_selector_ranges[0]);

	struct etc1_g_to_eac_conversion
	{
		uint8_t m_base;
		uint8_t m_table_mul; // mul*16+table
		uint16_t m_trans; // translates ETC1 selectors to ETC2_EAC_A8
	};
#endif // BASISD_SUPPORT_ETC2_EAC_A8 || BASISD_SUPPORT_ETC2_EAC_RG11

#if BASISD_SUPPORT_ETC2_EAC_A8

#if BASISD_WRITE_NEW_ETC2_EAC_A8_TABLES
	struct pack_eac_a8_results
	{
		uint32_t m_base;
		uint32_t m_table;
		uint32_t m_multiplier;
		basisu::vector<uint8_t> m_selectors;
		basisu::vector<uint8_t> m_selectors_temp;
	};

	static uint64_t pack_eac_a8_exhaustive(pack_eac_a8_results& results, const uint8_t* pPixels, uint32_t num_pixels)
	{
		results.m_selectors.resize(num_pixels);
		results.m_selectors_temp.resize(num_pixels);

		uint64_t best_err = UINT64_MAX;

		for (uint32_t base_color = 0; base_color < 256; base_color++)
		{
			for (uint32_t multiplier = 1; multiplier < 16; multiplier++)
			{
				for (uint32_t table = 0; table < 16; table++)
				{
					uint64_t total_err = 0;

					for (uint32_t i = 0; i < num_pixels; i++)
					{
						const int a = pPixels[i];

						uint32_t best_s_err = UINT32_MAX;
						uint32_t best_s = 0;
						for (uint32_t s = 0; s < 8; s++)
						{
							int v = (int)multiplier * g_eac_modifier_table[table][s] + (int)base_color;
							if (v < 0)
								v = 0;
							else if (v > 255)
								v = 255;

							uint32_t err = abs(a - v);
							if (err < best_s_err)
							{
								best_s_err = err;
								best_s = s;
							}
						}

						results.m_selectors_temp[i] = static_cast<uint8_t>(best_s);

						total_err += best_s_err * best_s_err;
						if (total_err >= best_err)
							break;
					}

					if (total_err < best_err)
					{
						best_err = total_err;
						results.m_base = base_color;
						results.m_multiplier = multiplier;
						results.m_table = table;
						results.m_selectors.swap(results.m_selectors_temp);
					}

				} // table

			} // multiplier

		} // base_color

		return best_err;
	}
#endif // BASISD_WRITE_NEW_ETC2_EAC_A8_TABLES
		
	static
#if !BASISD_WRITE_NEW_ETC2_EAC_A8_TABLES		
		const
#endif
		etc1_g_to_eac_conversion s_etc1_g_to_etc2_a8[32 * 8][NUM_ETC2_EAC_SELECTOR_RANGES] =
	{
		{ { 0,1,3328 },{ 0,1,3328 },{ 0,1,256 },{ 0,1,256 } },
		{ { 0,226,3936 },{ 0,226,3936 },{ 0,81,488 },{ 0,81,488 } },
		{ { 6,178,4012 },{ 6,178,4008 },{ 0,146,501 },{ 0,130,496 } },
		{ { 14,178,4012 },{ 14,178,4008 },{ 8,146,501 },{ 6,82,496 } },
		{ { 23,178,4012 },{ 23,178,4008 },{ 17,146,501 },{ 3,228,496 } },
		{ { 31,178,4012 },{ 31,178,4008 },{ 25,146,501 },{ 11,228,496 } },
		{ { 39,178,4012 },{ 39,178,4008 },{ 33,146,501 },{ 19,228,496 } },
		{ { 47,178,4012 },{ 47,178,4008 },{ 41,146,501 },{ 27,228,496 } },
		{ { 56,178,4012 },{ 56,178,4008 },{ 50,146,501 },{ 36,228,496 } },
		{ { 64,178,4012 },{ 64,178,4008 },{ 58,146,501 },{ 44,228,496 } },
		{ { 72,178,4012 },{ 72,178,4008 },{ 66,146,501 },{ 52,228,496 } },
		{ { 80,178,4012 },{ 80,178,4008 },{ 74,146,501 },{ 60,228,496 } },
		{ { 89,178,4012 },{ 89,178,4008 },{ 83,146,501 },{ 69,228,496 } },
		{ { 97,178,4012 },{ 97,178,4008 },{ 91,146,501 },{ 77,228,496 } },
		{ { 105,178,4012 },{ 105,178,4008 },{ 99,146,501 },{ 85,228,496 } },
		{ { 113,178,4012 },{ 113,178,4008 },{ 107,146,501 },{ 93,228,496 } },
		{ { 122,178,4012 },{ 122,178,4008 },{ 116,146,501 },{ 102,228,496 } },
		{ { 130,178,4012 },{ 130,178,4008 },{ 124,146,501 },{ 110,228,496 } },
		{ { 138,178,4012 },{ 138,178,4008 },{ 132,146,501 },{ 118,228,496 } },
		{ { 146,178,4012 },{ 146,178,4008 },{ 140,146,501 },{ 126,228,496 } },
		{ { 155,178,4012 },{ 155,178,4008 },{ 149,146,501 },{ 135,228,496 } },
		{ { 163,178,4012 },{ 163,178,4008 },{ 157,146,501 },{ 143,228,496 } },
		{ { 171,178,4012 },{ 171,178,4008 },{ 165,146,501 },{ 151,228,496 } },
		{ { 179,178,4012 },{ 179,178,4008 },{ 173,146,501 },{ 159,228,496 } },
		{ { 188,178,4012 },{ 188,178,4008 },{ 182,146,501 },{ 168,228,496 } },
		{ { 196,178,4012 },{ 196,178,4008 },{ 190,146,501 },{ 176,228,496 } },
		{ { 204,178,4012 },{ 204,178,4008 },{ 198,146,501 },{ 184,228,496 } },
		{ { 212,178,4012 },{ 212,178,4008 },{ 206,146,501 },{ 192,228,496 } },
		{ { 221,178,4012 },{ 221,178,4008 },{ 215,146,501 },{ 201,228,496 } },
		{ { 229,178,4012 },{ 229,178,4008 },{ 223,146,501 },{ 209,228,496 } },
		{ { 235,66,4012 },{ 221,100,4008 },{ 231,146,501 },{ 217,228,496 } },
		{ { 211,102,4085 },{ 118,31,4080 },{ 211,102,501 },{ 118,31,496 } },
		{ { 1,2,3328 },{ 1,2,3328 },{ 0,1,320 },{ 0,1,320 } },
		{ { 7,162,3905 },{ 7,162,3904 },{ 1,17,480 },{ 1,17,480 } },
		{ { 15,162,3906 },{ 15,162,3904 },{ 1,117,352 },{ 1,117,352 } },
		{ { 23,162,3906 },{ 23,162,3904 },{ 5,34,500 },{ 4,53,424 } },
		{ { 32,162,3906 },{ 32,162,3904 },{ 14,34,500 },{ 3,69,424 } },
		{ { 40,162,3906 },{ 40,162,3904 },{ 22,34,500 },{ 1,133,496 } },
		{ { 48,162,3906 },{ 48,162,3904 },{ 30,34,500 },{ 4,85,496 } },
		{ { 56,162,3906 },{ 56,162,3904 },{ 38,34,500 },{ 12,85,496 } },
		{ { 65,162,3906 },{ 65,162,3904 },{ 47,34,500 },{ 1,106,424 } },
		{ { 73,162,3906 },{ 73,162,3904 },{ 55,34,500 },{ 9,106,424 } },
		{ { 81,162,3906 },{ 81,162,3904 },{ 63,34,500 },{ 7,234,496 } },
		{ { 89,162,3906 },{ 89,162,3904 },{ 71,34,500 },{ 15,234,496 } },
		{ { 98,162,3906 },{ 98,162,3904 },{ 80,34,500 },{ 24,234,496 } },
		{ { 106,162,3906 },{ 106,162,3904 },{ 88,34,500 },{ 32,234,496 } },
		{ { 114,162,3906 },{ 114,162,3904 },{ 96,34,500 },{ 40,234,496 } },
		{ { 122,162,3906 },{ 122,162,3904 },{ 104,34,500 },{ 48,234,496 } },
		{ { 131,162,3906 },{ 131,162,3904 },{ 113,34,500 },{ 57,234,496 } },
		{ { 139,162,3906 },{ 139,162,3904 },{ 121,34,500 },{ 65,234,496 } },
		{ { 147,162,3906 },{ 147,162,3904 },{ 129,34,500 },{ 73,234,496 } },
		{ { 155,162,3906 },{ 155,162,3904 },{ 137,34,500 },{ 81,234,496 } },
		{ { 164,162,3906 },{ 164,162,3904 },{ 146,34,500 },{ 90,234,496 } },
		{ { 172,162,3906 },{ 172,162,3904 },{ 154,34,500 },{ 98,234,496 } },
		{ { 180,162,3906 },{ 180,162,3904 },{ 162,34,500 },{ 106,234,496 } },
		{ { 188,162,3906 },{ 188,162,3904 },{ 170,34,500 },{ 114,234,496 } },
		{ { 197,162,3906 },{ 197,162,3904 },{ 179,34,500 },{ 123,234,496 } },
		{ { 205,162,3906 },{ 205,162,3904 },{ 187,34,500 },{ 131,234,496 } },
		{ { 213,162,3906 },{ 213,162,3904 },{ 195,34,500 },{ 139,234,496 } },
		{ { 221,162,3906 },{ 221,162,3904 },{ 203,34,500 },{ 147,234,496 } },
		{ { 230,162,3906 },{ 230,162,3904 },{ 212,34,500 },{ 156,234,496 } },
		{ { 238,162,3906 },{ 174,106,4008 },{ 220,34,500 },{ 164,234,496 } },
		{ { 240,178,4001 },{ 182,106,4008 },{ 228,34,500 },{ 172,234,496 } },
		{ { 166,108,4085 },{ 115,31,4080 },{ 166,108,501 },{ 115,31,496 } },
		{ { 1,68,3328 },{ 1,68,3328 },{ 0,17,384 },{ 0,17,384 } },
		{ { 1,148,3904 },{ 1,148,3904 },{ 1,2,384 },{ 1,2,384 } },
		{ { 21,18,3851 },{ 21,18,3848 },{ 1,50,488 },{ 1,50,488 } },
		{ { 27,195,3851 },{ 29,18,3848 },{ 0,67,488 },{ 0,67,488 } },
		{ { 34,195,3907 },{ 38,18,3848 },{ 20,66,482 },{ 0,3,496 } },
		{ { 42,195,3907 },{ 46,18,3848 },{ 28,66,482 },{ 2,6,424 } },
		{ { 50,195,3907 },{ 54,18,3848 },{ 36,66,482 },{ 4,22,424 } },
		{ { 58,195,3907 },{ 62,18,3848 },{ 44,66,482 },{ 3,73,424 } },
		{ { 67,195,3907 },{ 71,18,3848 },{ 53,66,482 },{ 3,22,496 } },
		{ { 75,195,3907 },{ 79,18,3848 },{ 61,66,482 },{ 2,137,496 } },
		{ { 83,195,3907 },{ 87,18,3848 },{ 69,66,482 },{ 1,89,496 } },
		{ { 91,195,3907 },{ 95,18,3848 },{ 77,66,482 },{ 9,89,496 } },
		{ { 100,195,3907 },{ 104,18,3848 },{ 86,66,482 },{ 18,89,496 } },
		{ { 108,195,3907 },{ 112,18,3848 },{ 94,66,482 },{ 26,89,496 } },
		{ { 116,195,3907 },{ 120,18,3848 },{ 102,66,482 },{ 34,89,496 } },
		{ { 124,195,3907 },{ 128,18,3848 },{ 110,66,482 },{ 42,89,496 } },
		{ { 133,195,3907 },{ 137,18,3848 },{ 119,66,482 },{ 51,89,496 } },
		{ { 141,195,3907 },{ 145,18,3848 },{ 127,66,482 },{ 59,89,496 } },
		{ { 149,195,3907 },{ 153,18,3848 },{ 135,66,482 },{ 67,89,496 } },
		{ { 157,195,3907 },{ 161,18,3848 },{ 143,66,482 },{ 75,89,496 } },
		{ { 166,195,3907 },{ 170,18,3848 },{ 152,66,482 },{ 84,89,496 } },
		{ { 174,195,3907 },{ 178,18,3848 },{ 160,66,482 },{ 92,89,496 } },
		{ { 182,195,3907 },{ 186,18,3848 },{ 168,66,482 },{ 100,89,496 } },
		{ { 190,195,3907 },{ 194,18,3848 },{ 176,66,482 },{ 108,89,496 } },
		{ { 199,195,3907 },{ 203,18,3848 },{ 185,66,482 },{ 117,89,496 } },
		{ { 207,195,3907 },{ 211,18,3848 },{ 193,66,482 },{ 125,89,496 } },
		{ { 215,195,3907 },{ 219,18,3848 },{ 201,66,482 },{ 133,89,496 } },
		{ { 223,195,3907 },{ 227,18,3848 },{ 209,66,482 },{ 141,89,496 } },
		{ { 231,195,3907 },{ 168,89,4008 },{ 218,66,482 },{ 150,89,496 } },
		{ { 236,18,3907 },{ 176,89,4008 },{ 226,66,482 },{ 158,89,496 } },
		{ { 158,90,4085 },{ 103,31,4080 },{ 158,90,501 },{ 103,31,496 } },
		{ { 166,90,4085 },{ 111,31,4080 },{ 166,90,501 },{ 111,31,496 } },
		{ { 0,70,3328 },{ 0,70,3328 },{ 0,45,256 },{ 0,45,256 } },
		{ { 0,117,3904 },{ 0,117,3904 },{ 0,35,384 },{ 0,35,384 } },
		{ { 13,165,3905 },{ 13,165,3904 },{ 3,221,416 },{ 3,221,416 } },
		{ { 21,165,3906 },{ 21,165,3904 },{ 11,221,416 },{ 11,221,416 } },
		{ { 30,165,3906 },{ 30,165,3904 },{ 7,61,352 },{ 7,61,352 } },
		{ { 38,165,3906 },{ 38,165,3904 },{ 2,125,352 },{ 2,125,352 } },
		{ { 46,165,3906 },{ 46,165,3904 },{ 2,37,500 },{ 10,125,352 } },
		{ { 54,165,3906 },{ 54,165,3904 },{ 10,37,500 },{ 5,61,424 } },
		{ { 63,165,3906 },{ 63,165,3904 },{ 19,37,500 },{ 1,189,424 } },
		{ { 4,254,4012 },{ 71,165,3904 },{ 27,37,500 },{ 9,189,424 } },
		{ { 12,254,4012 },{ 79,165,3904 },{ 35,37,500 },{ 4,77,424 } },
		{ { 20,254,4012 },{ 87,165,3904 },{ 43,37,500 },{ 12,77,424 } },
		{ { 29,254,4012 },{ 96,165,3904 },{ 52,37,500 },{ 8,93,424 } },
		{ { 37,254,4012 },{ 104,165,3904 },{ 60,37,500 },{ 3,141,496 } },
		{ { 45,254,4012 },{ 112,165,3904 },{ 68,37,500 },{ 11,141,496 } },
		{ { 53,254,4012 },{ 120,165,3904 },{ 76,37,500 },{ 6,93,496 } },
		{ { 62,254,4012 },{ 129,165,3904 },{ 85,37,500 },{ 15,93,496 } },
		{ { 70,254,4012 },{ 137,165,3904 },{ 93,37,500 },{ 23,93,496 } },
		{ { 78,254,4012 },{ 145,165,3904 },{ 101,37,500 },{ 31,93,496 } },
		{ { 86,254,4012 },{ 153,165,3904 },{ 109,37,500 },{ 39,93,496 } },
		{ { 95,254,4012 },{ 162,165,3904 },{ 118,37,500 },{ 48,93,496 } },
		{ { 103,254,4012 },{ 170,165,3904 },{ 126,37,500 },{ 56,93,496 } },
		{ { 111,254,4012 },{ 178,165,3904 },{ 134,37,500 },{ 64,93,496 } },
		{ { 119,254,4012 },{ 186,165,3904 },{ 142,37,500 },{ 72,93,496 } },
		{ { 128,254,4012 },{ 195,165,3904 },{ 151,37,500 },{ 81,93,496 } },
		{ { 136,254,4012 },{ 203,165,3904 },{ 159,37,500 },{ 89,93,496 } },
		{ { 212,165,3906 },{ 136,77,4008 },{ 167,37,500 },{ 97,93,496 } },
		{ { 220,165,3394 },{ 131,93,4008 },{ 175,37,500 },{ 105,93,496 } },
		{ { 214,181,4001 },{ 140,93,4008 },{ 184,37,500 },{ 114,93,496 } },
		{ { 222,181,4001 },{ 148,93,4008 },{ 192,37,500 },{ 122,93,496 } },
		{ { 114,95,4085 },{ 99,31,4080 },{ 114,95,501 },{ 99,31,496 } },
		{ { 122,95,4085 },{ 107,31,4080 },{ 122,95,501 },{ 107,31,496 } },
		{ { 0,102,3840 },{ 0,102,3840 },{ 0,18,384 },{ 0,18,384 } },
		{ { 5,167,3904 },{ 5,167,3904 },{ 0,13,256 },{ 0,13,256 } },
		{ { 4,54,3968 },{ 4,54,3968 },{ 1,67,448 },{ 1,67,448 } },
		{ { 30,198,3850 },{ 30,198,3848 },{ 0,3,480 },{ 0,3,480 } },
		{ { 39,198,3850 },{ 39,198,3848 },{ 3,52,488 },{ 3,52,488 } },
		{ { 47,198,3851 },{ 47,198,3848 },{ 3,4,488 },{ 3,4,488 } },
		{ { 55,198,3851 },{ 55,198,3848 },{ 1,70,488 },{ 1,70,488 } },
		{ { 54,167,3906 },{ 63,198,3848 },{ 3,22,488 },{ 3,22,488 } },
		{ { 62,167,3906 },{ 72,198,3848 },{ 24,118,488 },{ 0,6,496 } },
		{ { 70,167,3906 },{ 80,198,3848 },{ 32,118,488 },{ 2,89,488 } },
		{ { 78,167,3906 },{ 88,198,3848 },{ 40,118,488 },{ 1,73,496 } },
		{ { 86,167,3906 },{ 96,198,3848 },{ 48,118,488 },{ 0,28,424 } },
		{ { 95,167,3906 },{ 105,198,3848 },{ 57,118,488 },{ 9,28,424 } },
		{ { 103,167,3906 },{ 113,198,3848 },{ 65,118,488 },{ 5,108,496 } },
		{ { 111,167,3906 },{ 121,198,3848 },{ 73,118,488 },{ 13,108,496 } },
		{ { 119,167,3906 },{ 129,198,3848 },{ 81,118,488 },{ 21,108,496 } },
		{ { 128,167,3906 },{ 138,198,3848 },{ 90,118,488 },{ 6,28,496 } },
		{ { 136,167,3906 },{ 146,198,3848 },{ 98,118,488 },{ 14,28,496 } },
		{ { 144,167,3906 },{ 154,198,3848 },{ 106,118,488 },{ 22,28,496 } },
		{ { 152,167,3906 },{ 162,198,3848 },{ 114,118,488 },{ 30,28,496 } },
		{ { 161,167,3906 },{ 171,198,3848 },{ 123,118,488 },{ 39,28,496 } },
		{ { 169,167,3906 },{ 179,198,3848 },{ 131,118,488 },{ 47,28,496 } },
		{ { 177,167,3906 },{ 187,198,3848 },{ 139,118,488 },{ 55,28,496 } },
		{ { 185,167,3906 },{ 195,198,3848 },{ 147,118,488 },{ 63,28,496 } },
		{ { 194,167,3906 },{ 120,12,4008 },{ 156,118,488 },{ 72,28,496 } },
		{ { 206,198,3907 },{ 116,28,4008 },{ 164,118,488 },{ 80,28,496 } },
		{ { 214,198,3907 },{ 124,28,4008 },{ 172,118,488 },{ 88,28,496 } },
		{ { 222,198,3395 },{ 132,28,4008 },{ 180,118,488 },{ 96,28,496 } },
		{ { 207,134,4001 },{ 141,28,4008 },{ 189,118,488 },{ 105,28,496 } },
		{ { 95,30,4085 },{ 86,31,4080 },{ 95,30,501 },{ 86,31,496 } },
		{ { 103,30,4085 },{ 94,31,4080 },{ 103,30,501 },{ 94,31,496 } },
		{ { 111,30,4085 },{ 102,31,4080 },{ 111,30,501 },{ 102,31,496 } },
		{ { 0,104,3840 },{ 0,104,3840 },{ 0,18,448 },{ 0,18,448 } },
		{ { 4,39,3904 },{ 4,39,3904 },{ 0,4,384 },{ 0,4,384 } },
		{ { 0,56,3968 },{ 0,56,3968 },{ 0,84,448 },{ 0,84,448 } },
		{ { 6,110,3328 },{ 6,110,3328 },{ 0,20,448 },{ 0,20,448 } },
		{ { 41,200,3850 },{ 41,200,3848 },{ 1,4,480 },{ 1,4,480 } },
		{ { 49,200,3850 },{ 49,200,3848 },{ 1,8,416 },{ 1,8,416 } },
		{ { 57,200,3851 },{ 57,200,3848 },{ 1,38,488 },{ 1,38,488 } },
		{ { 65,200,3851 },{ 65,200,3848 },{ 1,120,488 },{ 1,120,488 } },
		{ { 74,200,3851 },{ 74,200,3848 },{ 2,72,488 },{ 2,72,488 } },
		{ { 69,6,3907 },{ 82,200,3848 },{ 2,24,488 },{ 2,24,488 } },
		{ { 77,6,3907 },{ 90,200,3848 },{ 26,120,488 },{ 10,24,488 } },
		{ { 97,63,3330 },{ 98,200,3848 },{ 34,120,488 },{ 2,8,496 } },
		{ { 106,63,3330 },{ 107,200,3848 },{ 43,120,488 },{ 3,92,488 } },
		{ { 114,63,3330 },{ 115,200,3848 },{ 51,120,488 },{ 11,92,488 } },
		{ { 122,63,3330 },{ 123,200,3848 },{ 59,120,488 },{ 7,76,496 } },
		{ { 130,63,3330 },{ 131,200,3848 },{ 67,120,488 },{ 15,76,496 } },
		{ { 139,63,3330 },{ 140,200,3848 },{ 76,120,488 },{ 24,76,496 } },
		{ { 147,63,3330 },{ 148,200,3848 },{ 84,120,488 },{ 32,76,496 } },
		{ { 155,63,3330 },{ 156,200,3848 },{ 92,120,488 },{ 40,76,496 } },
		{ { 163,63,3330 },{ 164,200,3848 },{ 100,120,488 },{ 48,76,496 } },
		{ { 172,63,3330 },{ 173,200,3848 },{ 109,120,488 },{ 57,76,496 } },
		{ { 184,6,3851 },{ 181,200,3848 },{ 117,120,488 },{ 65,76,496 } },
		{ { 192,6,3851 },{ 133,28,3936 },{ 125,120,488 },{ 73,76,496 } },
		{ { 189,200,3907 },{ 141,28,3936 },{ 133,120,488 },{ 81,76,496 } },
		{ { 198,200,3907 },{ 138,108,4000 },{ 142,120,488 },{ 90,76,496 } },
		{ { 206,200,3907 },{ 146,108,4000 },{ 150,120,488 },{ 98,76,496 } },
		{ { 214,200,3395 },{ 154,108,4000 },{ 158,120,488 },{ 106,76,496 } },
		{ { 190,136,4001 },{ 162,108,4000 },{ 166,120,488 },{ 114,76,496 } },
		{ { 123,30,4076 },{ 87,15,4080 },{ 123,30,492 },{ 87,15,496 } },
		{ { 117,110,4084 },{ 80,31,4080 },{ 117,110,500 },{ 80,31,496 } },
		{ { 125,110,4084 },{ 88,31,4080 },{ 125,110,500 },{ 88,31,496 } },
		{ { 133,110,4084 },{ 96,31,4080 },{ 133,110,500 },{ 96,31,496 } },
		{ { 9,56,3904 },{ 9,56,3904 },{ 0,67,448 },{ 0,67,448 } },
		{ { 1,8,3904 },{ 1,8,3904 },{ 1,84,448 },{ 1,84,448 } },
		{ { 1,124,3904 },{ 1,124,3904 },{ 0,39,384 },{ 0,39,384 } },
		{ { 9,124,3904 },{ 9,124,3904 },{ 1,4,448 },{ 1,4,448 } },
		{ { 6,76,3904 },{ 6,76,3904 },{ 0,70,448 },{ 0,70,448 } },
		{ { 62,6,3859 },{ 62,6,3856 },{ 2,38,480 },{ 2,38,480 } },
		{ { 70,6,3859 },{ 70,6,3856 },{ 5,43,416 },{ 5,43,416 } },
		{ { 78,6,3859 },{ 78,6,3856 },{ 2,11,416 },{ 2,11,416 } },
		{ { 87,6,3859 },{ 87,6,3856 },{ 0,171,488 },{ 0,171,488 } },
		{ { 67,8,3906 },{ 95,6,3856 },{ 8,171,488 },{ 8,171,488 } },
		{ { 75,8,3907 },{ 103,6,3856 },{ 5,123,488 },{ 5,123,488 } },
		{ { 83,8,3907 },{ 111,6,3856 },{ 2,75,488 },{ 2,75,488 } },
		{ { 92,8,3907 },{ 120,6,3856 },{ 0,27,488 },{ 0,27,488 } },
		{ { 100,8,3907 },{ 128,6,3856 },{ 8,27,488 },{ 8,27,488 } },
		{ { 120,106,3843 },{ 136,6,3856 },{ 100,6,387 },{ 16,27,488 } },
		{ { 128,106,3843 },{ 144,6,3856 },{ 108,6,387 },{ 2,11,496 } },
		{ { 137,106,3843 },{ 153,6,3856 },{ 117,6,387 },{ 11,11,496 } },
		{ { 145,106,3843 },{ 161,6,3856 },{ 125,6,387 },{ 19,11,496 } },
		{ { 163,8,3851 },{ 137,43,3904 },{ 133,6,387 },{ 27,11,496 } },
		{ { 171,8,3851 },{ 101,11,4000 },{ 141,6,387 },{ 35,11,496 } },
		{ { 180,8,3851 },{ 110,11,4000 },{ 150,6,387 },{ 44,11,496 } },
		{ { 188,8,3851 },{ 118,11,4000 },{ 158,6,387 },{ 52,11,496 } },
		{ { 172,72,3907 },{ 126,11,4000 },{ 166,6,387 },{ 60,11,496 } },
		{ { 174,6,3971 },{ 134,11,4000 },{ 174,6,387 },{ 68,11,496 } },
		{ { 183,6,3971 },{ 143,11,4000 },{ 183,6,387 },{ 77,11,496 } },
		{ { 191,6,3971 },{ 151,11,4000 },{ 191,6,387 },{ 85,11,496 } },
		{ { 199,6,3971 },{ 159,11,4000 },{ 199,6,387 },{ 93,11,496 } },
		{ { 92,12,4084 },{ 69,15,4080 },{ 92,12,500 },{ 69,15,496 } },
		{ { 101,12,4084 },{ 78,15,4080 },{ 101,12,500 },{ 78,15,496 } },
		{ { 109,12,4084 },{ 86,15,4080 },{ 109,12,500 },{ 86,15,496 } },
		{ { 117,12,4084 },{ 79,31,4080 },{ 117,12,500 },{ 79,31,496 } },
		{ { 125,12,4084 },{ 87,31,4080 },{ 125,12,500 },{ 87,31,496 } },
		{ { 71,8,3602 },{ 71,8,3600 },{ 2,21,384 },{ 2,21,384 } },
		{ { 79,8,3611 },{ 79,8,3608 },{ 0,69,448 },{ 0,69,448 } },
		{ { 87,8,3611 },{ 87,8,3608 },{ 0,23,384 },{ 0,23,384 } },
		{ { 95,8,3611 },{ 95,8,3608 },{ 1,5,448 },{ 1,5,448 } },
		{ { 104,8,3611 },{ 104,8,3608 },{ 0,88,448 },{ 0,88,448 } },
		{ { 112,8,3611 },{ 112,8,3608 },{ 0,72,448 },{ 0,72,448 } },
		{ { 120,8,3611 },{ 121,8,3608 },{ 36,21,458 },{ 36,21,456 } },
		{ { 133,47,3091 },{ 129,8,3608 },{ 44,21,458 },{ 44,21,456 } },
		{ { 142,47,3091 },{ 138,8,3608 },{ 53,21,459 },{ 53,21,456 } },
		{ { 98,12,3850 },{ 98,12,3848 },{ 61,21,459 },{ 61,21,456 } },
		{ { 106,12,3850 },{ 106,12,3848 },{ 10,92,480 },{ 69,21,456 } },
		{ { 114,12,3851 },{ 114,12,3848 },{ 18,92,480 },{ 77,21,456 } },
		{ { 87,12,3906 },{ 87,12,3904 },{ 3,44,488 },{ 86,21,456 } },
		{ { 95,12,3906 },{ 95,12,3904 },{ 11,44,488 },{ 94,21,456 } },
		{ { 103,12,3906 },{ 103,12,3904 },{ 19,44,488 },{ 102,21,456 } },
		{ { 111,12,3907 },{ 111,12,3904 },{ 27,44,489 },{ 110,21,456 } },
		{ { 120,12,3907 },{ 120,12,3904 },{ 36,44,489 },{ 119,21,456 } },
		{ { 128,12,3907 },{ 128,12,3904 },{ 44,44,489 },{ 127,21,456 } },
		{ { 136,12,3907 },{ 136,12,3904 },{ 52,44,489 },{ 135,21,456 } },
		{ { 144,12,3907 },{ 144,12,3904 },{ 60,44,489 },{ 143,21,456 } },
		{ { 153,12,3907 },{ 153,12,3904 },{ 69,44,490 },{ 152,21,456 } },
		{ { 161,12,3395 },{ 149,188,3968 },{ 77,44,490 },{ 160,21,456 } },
		{ { 169,12,3395 },{ 198,21,3928 },{ 85,44,490 },{ 168,21,456 } },
		{ { 113,95,4001 },{ 201,69,3992 },{ 125,8,483 },{ 176,21,456 } },
		{ { 122,95,4001 },{ 200,21,3984 },{ 134,8,483 },{ 185,21,456 } },
		{ { 142,8,4067 },{ 208,21,3984 },{ 142,8,483 },{ 193,21,456 } },
		{ { 151,8,4067 },{ 47,15,4080 },{ 151,8,483 },{ 47,15,496 } },
		{ { 159,8,4067 },{ 55,15,4080 },{ 159,8,483 },{ 55,15,496 } },
		{ { 168,8,4067 },{ 64,15,4080 },{ 168,8,483 },{ 64,15,496 } },
		{ { 160,40,4075 },{ 72,15,4080 },{ 160,40,491 },{ 72,15,496 } },
		{ { 168,40,4075 },{ 80,15,4080 },{ 168,40,491 },{ 80,15,496 } },
		{ { 144,8,4082 },{ 88,15,4080 },{ 144,8,498 },{ 88,15,496 } }
	};
#endif // BASISD_SUPPORT_ETC2_EAC_A8

#if BASISD_WRITE_NEW_ETC2_EAC_A8_TABLES
	static void create_etc2_eac_a8_conversion_table()
	{
		FILE* pFile = fopen("basisu_decoder_tables_etc2_eac_a8.inc", "w");

		for (uint32_t inten = 0; inten < 8; inten++)
		{
			for (uint32_t base = 0; base < 32; base++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(base, base, base, 255), false), inten);

				fprintf(pFile, "{");

				for (uint32_t sel_range = 0; sel_range < NUM_ETC2_EAC_SELECTOR_RANGES; sel_range++)
				{
					const uint32_t low_selector = s_etc2_eac_selector_ranges[sel_range].m_low;
					const uint32_t high_selector = s_etc2_eac_selector_ranges[sel_range].m_high;

					// We have a ETC1 base color and intensity, and a used selector range from low_selector-high_selector.
					// Now find the best ETC2 EAC A8 base/table/multiplier that fits these colors.

					uint8_t pixels[4];
					uint32_t num_pixels = 0;
					for (uint32_t s = low_selector; s <= high_selector; s++)
						pixels[num_pixels++] = block_colors[s].g;

					pack_eac_a8_results pack_results;
					pack_eac_a8_exhaustive(pack_results, pixels, num_pixels);

					etc1_g_to_eac_conversion& c = s_etc1_g_to_etc2_a8[base + inten * 32][sel_range];

					c.m_base = pack_results.m_base;
					c.m_table_mul = pack_results.m_table * 16 + pack_results.m_multiplier;
					c.m_trans = 0;

					for (uint32_t s = 0; s < 4; s++)
					{
						if ((s < low_selector) || (s > high_selector))
							continue;

						uint32_t etc2_selector = pack_results.m_selectors[s - low_selector];

						c.m_trans |= (etc2_selector << (s * 3));
					}

					fprintf(pFile, "{%u,%u,%u}", c.m_base, c.m_table_mul, c.m_trans);
					if (sel_range < (NUM_ETC2_EAC_SELECTOR_RANGES - 1))
						fprintf(pFile, ",");
				}

				fprintf(pFile, "},\n");
			}
		}

		fclose(pFile);
	}
#endif

#if BASISD_WRITE_NEW_ETC2_EAC_R11_TABLES
	struct pack_eac_r11_results
	{
		uint32_t m_base;
		uint32_t m_table;
		uint32_t m_multiplier;
		basisu::vector<uint8_t> m_selectors;
		basisu::vector<uint8_t> m_selectors_temp;
	};

	static uint64_t pack_eac_r11_exhaustive(pack_eac_r11_results& results, const uint8_t* pPixels, uint32_t num_pixels)
	{
		results.m_selectors.resize(num_pixels);
		results.m_selectors_temp.resize(num_pixels);

		uint64_t best_err = UINT64_MAX;

		for (uint32_t base_color = 0; base_color < 256; base_color++)
		{
			for (uint32_t multiplier = 0; multiplier < 16; multiplier++)
			{
				for (uint32_t table = 0; table < 16; table++)
				{
					uint64_t total_err = 0;

					for (uint32_t i = 0; i < num_pixels; i++)
					{
						// Convert 8-bit input to 11-bits
						const int a = (pPixels[i] * 2047 + 128) / 255;

						uint32_t best_s_err = UINT32_MAX;
						uint32_t best_s = 0;
						for (uint32_t s = 0; s < 8; s++)
						{
							int v = (int)(multiplier ? (multiplier * 8) : 1) * g_eac_modifier_table[table][s] + (int)base_color * 8 + 4;
							if (v < 0)
								v = 0;
							else if (v > 2047)
								v = 2047;

							uint32_t err = abs(a - v);
							if (err < best_s_err)
							{
								best_s_err = err;
								best_s = s;
							}
						}

						results.m_selectors_temp[i] = static_cast<uint8_t>(best_s);

						total_err += best_s_err * best_s_err;
						if (total_err >= best_err)
							break;
					}

					if (total_err < best_err)
					{
						best_err = total_err;
						results.m_base = base_color;
						results.m_multiplier = multiplier;
						results.m_table = table;
						results.m_selectors.swap(results.m_selectors_temp);
					}

				} // table

			} // multiplier

		} // base_color

		return best_err;
	}

	static void create_etc2_eac_r11_conversion_table()
	{
		FILE* pFile = nullptr;
		fopen_s(&pFile, "basisu_decoder_tables_etc2_eac_r11.inc", "w");

		for (uint32_t inten = 0; inten < 8; inten++)
		{
			for (uint32_t base = 0; base < 32; base++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(base, base, base, 255), false), inten);

				fprintf(pFile, "{");

				for (uint32_t sel_range = 0; sel_range < NUM_ETC2_EAC_SELECTOR_RANGES; sel_range++)
				{
					const uint32_t low_selector = s_etc2_eac_selector_ranges[sel_range].m_low;
					const uint32_t high_selector = s_etc2_eac_selector_ranges[sel_range].m_high;

					// We have a ETC1 base color and intensity, and a used selector range from low_selector-high_selector.
					// Now find the best ETC2 EAC R11 base/table/multiplier that fits these colors.

					uint8_t pixels[4];
					uint32_t num_pixels = 0;
					for (uint32_t s = low_selector; s <= high_selector; s++)
						pixels[num_pixels++] = block_colors[s].g;

					pack_eac_r11_results pack_results;
					pack_eac_r11_exhaustive(pack_results, pixels, num_pixels);

					etc1_g_to_eac_conversion c;

					c.m_base = (uint8_t)pack_results.m_base;
					c.m_table_mul = (uint8_t)(pack_results.m_table * 16 + pack_results.m_multiplier);
					c.m_trans = 0;

					for (uint32_t s = 0; s < 4; s++)
					{
						if ((s < low_selector) || (s > high_selector))
							continue;

						uint32_t etc2_selector = pack_results.m_selectors[s - low_selector];

						c.m_trans |= (etc2_selector << (s * 3));
					}

					fprintf(pFile, "{%u,%u,%u}", c.m_base, c.m_table_mul, c.m_trans);
					if (sel_range < (NUM_ETC2_EAC_SELECTOR_RANGES - 1))
						fprintf(pFile, ",");
				}

				fprintf(pFile, "},\n");
			}
		}

		fclose(pFile);
	}
#endif // BASISD_WRITE_NEW_ETC2_EAC_R11_TABLES

#if BASISD_WRITE_NEW_ASTC_TABLES
	static void create_etc1_to_astc_conversion_table_0_47();
	static void create_etc1_to_astc_conversion_table_0_255();
#endif

#if BASISD_SUPPORT_ASTC
	static void transcoder_init_astc();
#endif

#if BASISD_WRITE_NEW_BC7_MODE5_TABLES
	static void create_etc1_to_bc7_m5_color_conversion_table();
	static void create_etc1_to_bc7_m5_alpha_conversion_table();
#endif

#if BASISD_SUPPORT_BC7_MODE5
	static void transcoder_init_bc7_mode5();
#endif

#if BASISD_WRITE_NEW_ATC_TABLES
	static void create_etc1s_to_atc_conversion_tables();
#endif

#if BASISD_SUPPORT_ATC
	static void transcoder_init_atc();
#endif

#if BASISD_SUPPORT_PVRTC2
	static void transcoder_init_pvrtc2();
#endif

#if BASISD_SUPPORT_UASTC
	void uastc_init();
#endif

#if BASISD_SUPPORT_UASTC_HDR	
	namespace astc_6x6_hdr
	{
		static void init_quantize_tables();
		static void fast_encode_bc6h_init();
	}
#endif

#if BASISD_SUPPORT_BC7_MODE5
	namespace bc7_mode_5_encoder
	{
		void encode_bc7_mode5_init();
	}
#endif

	static bool g_transcoder_initialized;
		
	// Library global initialization. Requires ~9 milliseconds when compiled and executed natively on a Core i7 2.2 GHz.
	// If this is too slow, these computed tables can easilky be moved to be compiled in.
	void basisu_transcoder_init()
	{
		if (g_transcoder_initialized)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::basisu_transcoder_init: Called more than once\n");      
			return;
		}
         
		BASISU_DEVEL_ERROR("basisu_transcoder::basisu_transcoder_init: Initializing (this is not an error)\n");      

#if BASISD_SUPPORT_UASTC
		uastc_init();
#endif

#if BASISD_SUPPORT_UASTC_HDR
		// TODO: Examine this, optimize for startup time/mem utilization.
		astc_helpers::init_tables(false);

		astc_hdr_core_init();
#endif

#if BASISD_SUPPORT_ASTC
		transcoder_init_astc();
#endif
				
#if BASISD_WRITE_NEW_ASTC_TABLES
		create_etc1_to_astc_conversion_table_0_47();
		create_etc1_to_astc_conversion_table_0_255();
		exit(0);
#endif

#if BASISD_WRITE_NEW_BC7_MODE5_TABLES
		create_etc1_to_bc7_m5_color_conversion_table();
		create_etc1_to_bc7_m5_alpha_conversion_table();
		exit(0);
#endif

#if BASISD_WRITE_NEW_DXT1_TABLES
		create_etc1_to_dxt1_5_conversion_table();
		create_etc1_to_dxt1_6_conversion_table();
		exit(0);
#endif

#if BASISD_WRITE_NEW_ETC2_EAC_A8_TABLES
		create_etc2_eac_a8_conversion_table();
		exit(0);
#endif

#if BASISD_WRITE_NEW_ATC_TABLES
		create_etc1s_to_atc_conversion_tables();
		exit(0);
#endif

#if BASISD_WRITE_NEW_ETC2_EAC_R11_TABLES
		create_etc2_eac_r11_conversion_table();
		exit(0);
#endif

#if BASISD_SUPPORT_DXT1 || BASISD_SUPPORT_UASTC
		uint8_t bc1_expand5[32];
		for (int i = 0; i < 32; i++)
			bc1_expand5[i] = static_cast<uint8_t>((i << 3) | (i >> 2));
		prepare_bc1_single_color_table(g_bc1_match5_equals_1, bc1_expand5, 32, 32, 1);
		prepare_bc1_single_color_table(g_bc1_match5_equals_0, bc1_expand5, 1, 32, 0);

		uint8_t bc1_expand6[64];
		for (int i = 0; i < 64; i++)
			bc1_expand6[i] = static_cast<uint8_t>((i << 2) | (i >> 4));
		prepare_bc1_single_color_table(g_bc1_match6_equals_1, bc1_expand6, 64, 64, 1);
		prepare_bc1_single_color_table(g_bc1_match6_equals_0, bc1_expand6, 1, 64, 0);

#if 0
		for (uint32_t i = 0; i < 256; i++)
		{
			printf("%u %u %u\n", i, (i * 63 + 127) / 255, g_bc1_match6_equals_0[i].m_hi);
		}
		exit(0);
#endif

#endif

#if BASISD_SUPPORT_DXT1
		for (uint32_t i = 0; i < NUM_ETC1_TO_DXT1_SELECTOR_RANGES; i++)
		{
			uint32_t l = g_etc1_to_dxt1_selector_ranges[i].m_low;
			uint32_t h = g_etc1_to_dxt1_selector_ranges[i].m_high;
			g_etc1_to_dxt1_selector_range_index[l][h] = i;
		}

		for (uint32_t sm = 0; sm < NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS; sm++)
		{
			uint8_t etc1_to_dxt1_selector_mappings_raw_dxt1[4];
			uint8_t etc1_to_dxt1_selector_mappings_raw_dxt1_inv[4];

			for (uint32_t j = 0; j < 4; j++)
			{
				static const uint8_t s_linear_dxt1_to_dxt1[4] = { 0, 2, 3, 1 };
				static const uint8_t s_dxt1_inverted_xlat[4] = { 1, 0, 3, 2 };

				etc1_to_dxt1_selector_mappings_raw_dxt1[j] = (uint8_t)s_linear_dxt1_to_dxt1[g_etc1_to_dxt1_selector_mappings[sm][j]];
				etc1_to_dxt1_selector_mappings_raw_dxt1_inv[j] = (uint8_t)s_dxt1_inverted_xlat[etc1_to_dxt1_selector_mappings_raw_dxt1[j]];
			}

			for (uint32_t i = 0; i < 256; i++)
			{
				uint32_t k = 0, k_inv = 0;
				for (uint32_t s = 0; s < 4; s++)
				{
					k |= (etc1_to_dxt1_selector_mappings_raw_dxt1[(i >> (s * 2)) & 3] << (s * 2));
					k_inv |= (etc1_to_dxt1_selector_mappings_raw_dxt1_inv[(i >> (s * 2)) & 3] << (s * 2));
				}
				g_etc1_to_dxt1_selector_mappings_raw_dxt1_256[sm][i] = (uint8_t)k;
				g_etc1_to_dxt1_selector_mappings_raw_dxt1_inv_256[sm][i] = (uint8_t)k_inv;
			}
		}
#endif

#if BASISD_SUPPORT_BC7_MODE5
		transcoder_init_bc7_mode5();
#endif

#if BASISD_SUPPORT_ATC
		transcoder_init_atc();
#endif

#if BASISD_SUPPORT_PVRTC2
		transcoder_init_pvrtc2();
#endif

#if BASISD_SUPPORT_UASTC_HDR
		bc6h_enc_init();
		astc_6x6_hdr::init_quantize_tables();
		fast_encode_bc6h_init();
#endif
		
#if BASISD_SUPPORT_BC7_MODE5
		bc7_mode_5_encoder::encode_bc7_mode5_init();
#endif
				
		g_transcoder_initialized = true;
	}

#if BASISD_SUPPORT_DXT1
	static void convert_etc1s_to_dxt1(dxt1_block* pDst_block, const endpoint *pEndpoints, const selector* pSelector, bool use_threecolor_blocks)
	{
#if !BASISD_WRITE_NEW_DXT1_TABLES
		const uint32_t low_selector = pSelector->m_lo_selector;
		const uint32_t high_selector = pSelector->m_hi_selector;

		const color32& base_color = pEndpoints->m_color5;
		const uint32_t inten_table = pEndpoints->m_inten5;

		if (low_selector == high_selector)
		{
			uint32_t r, g, b;
			decoder_etc_block::get_block_color5(base_color, inten_table, low_selector, r, g, b);

			uint32_t mask = 0xAA;
			uint32_t max16 = (g_bc1_match5_equals_1[r].m_hi << 11) | (g_bc1_match6_equals_1[g].m_hi << 5) | g_bc1_match5_equals_1[b].m_hi;
			uint32_t min16 = (g_bc1_match5_equals_1[r].m_lo << 11) | (g_bc1_match6_equals_1[g].m_lo << 5) | g_bc1_match5_equals_1[b].m_lo;

			if ((!use_threecolor_blocks) && (min16 == max16))
			{
				// This is an annoying edge case that impacts BC3.
				// This is to guarantee that BC3 blocks never use punchthrough alpha (3 color) mode, which isn't supported on some (all?) GPU's.
				mask = 0;

				// Make l > h
				if (min16 > 0)
					min16--;
				else
				{
					// l = h = 0
					assert(min16 == max16 && max16 == 0);

					max16 = 1;
					min16 = 0;
					mask = 0x55;
				}

				assert(max16 > min16);
			}

			if (max16 < min16)
			{
				std::swap(max16, min16);
				mask ^= 0x55;
			}

			pDst_block->set_low_color(static_cast<uint16_t>(max16));
			pDst_block->set_high_color(static_cast<uint16_t>(min16));
			pDst_block->m_selectors[0] = static_cast<uint8_t>(mask);
			pDst_block->m_selectors[1] = static_cast<uint8_t>(mask);
			pDst_block->m_selectors[2] = static_cast<uint8_t>(mask);
			pDst_block->m_selectors[3] = static_cast<uint8_t>(mask);

			return;
		}
		else if ((inten_table >= 7) && (pSelector->m_num_unique_selectors == 2) && (pSelector->m_lo_selector == 0) && (pSelector->m_hi_selector == 3))
		{
			color32 block_colors[4];

			decoder_etc_block::get_block_colors5(block_colors, base_color, inten_table);

			const uint32_t r0 = block_colors[0].r;
			const uint32_t g0 = block_colors[0].g;
			const uint32_t b0 = block_colors[0].b;

			const uint32_t r1 = block_colors[3].r;
			const uint32_t g1 = block_colors[3].g;
			const uint32_t b1 = block_colors[3].b;

			uint32_t max16 = (g_bc1_match5_equals_0[r0].m_hi << 11) | (g_bc1_match6_equals_0[g0].m_hi << 5) | g_bc1_match5_equals_0[b0].m_hi;
			uint32_t min16 = (g_bc1_match5_equals_0[r1].m_hi << 11) | (g_bc1_match6_equals_0[g1].m_hi << 5) | g_bc1_match5_equals_0[b1].m_hi;

			uint32_t l = 0, h = 1;

			if (min16 == max16)
			{
				// Make l > h
				if (min16 > 0)
				{
					min16--;

					l = 0;
					h = 0;
				}
				else
				{
					// l = h = 0
					assert(min16 == max16 && max16 == 0);

					max16 = 1;
					min16 = 0;

					l = 1;
					h = 1;
				}

				assert(max16 > min16);
			}

			if (max16 < min16)
			{
				std::swap(max16, min16);
				l = 1;
				h = 0;
			}

			pDst_block->set_low_color((uint16_t)max16);
			pDst_block->set_high_color((uint16_t)min16);

			for (uint32_t y = 0; y < 4; y++)
			{
				for (uint32_t x = 0; x < 4; x++)
				{
					uint32_t s = pSelector->get_selector(x, y);
					pDst_block->set_selector(x, y, (s == 3) ? h : l);
				}
			}

			return;
		}

		const uint32_t selector_range_table = g_etc1_to_dxt1_selector_range_index[low_selector][high_selector];

		//[32][8][RANGES][MAPPING]
		const etc1_to_dxt1_56_solution* pTable_r = &g_etc1_to_dxt_5[(inten_table * 32 + base_color.r) * (NUM_ETC1_TO_DXT1_SELECTOR_RANGES * NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS];
		const etc1_to_dxt1_56_solution* pTable_g = &g_etc1_to_dxt_6[(inten_table * 32 + base_color.g) * (NUM_ETC1_TO_DXT1_SELECTOR_RANGES * NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS];
		const etc1_to_dxt1_56_solution* pTable_b = &g_etc1_to_dxt_5[(inten_table * 32 + base_color.b) * (NUM_ETC1_TO_DXT1_SELECTOR_RANGES * NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS];

		uint32_t best_err = UINT_MAX;
		uint32_t best_mapping = 0;

		assert(NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS == 10);
#define DO_ITER(m) { uint32_t total_err = pTable_r[m].m_err + pTable_g[m].m_err + pTable_b[m].m_err; if (total_err < best_err) { best_err = total_err; best_mapping = m; } }
		DO_ITER(0); DO_ITER(1); DO_ITER(2); DO_ITER(3); DO_ITER(4);
		DO_ITER(5); DO_ITER(6); DO_ITER(7); DO_ITER(8); DO_ITER(9);
#undef DO_ITER

		uint32_t l = dxt1_block::pack_unscaled_color(pTable_r[best_mapping].m_lo, pTable_g[best_mapping].m_lo, pTable_b[best_mapping].m_lo);
		uint32_t h = dxt1_block::pack_unscaled_color(pTable_r[best_mapping].m_hi, pTable_g[best_mapping].m_hi, pTable_b[best_mapping].m_hi);

		const uint8_t* pSelectors_xlat_256 = &g_etc1_to_dxt1_selector_mappings_raw_dxt1_256[best_mapping][0];

		if (l < h)
		{
			std::swap(l, h);
			pSelectors_xlat_256 = &g_etc1_to_dxt1_selector_mappings_raw_dxt1_inv_256[best_mapping][0];
		}
				
		pDst_block->set_low_color(static_cast<uint16_t>(l));
		pDst_block->set_high_color(static_cast<uint16_t>(h));

		if (l == h)
		{
			uint8_t mask = 0;

			if (!use_threecolor_blocks)
			{
				// This is an annoying edge case that impacts BC3.

				// Make l > h
				if (h > 0)
					h--;
				else
				{
					// l = h = 0
					assert(l == h && h == 0);

					h = 0;
					l = 1;
					mask = 0x55;
				}

				assert(l > h);
				pDst_block->set_low_color(static_cast<uint16_t>(l));
				pDst_block->set_high_color(static_cast<uint16_t>(h));
			}

			pDst_block->m_selectors[0] = mask;
			pDst_block->m_selectors[1] = mask;
			pDst_block->m_selectors[2] = mask;
			pDst_block->m_selectors[3] = mask;

			return;
		}

		pDst_block->m_selectors[0] = pSelectors_xlat_256[pSelector->m_selectors[0]];
		pDst_block->m_selectors[1] = pSelectors_xlat_256[pSelector->m_selectors[1]];
		pDst_block->m_selectors[2] = pSelectors_xlat_256[pSelector->m_selectors[2]];
		pDst_block->m_selectors[3] = pSelectors_xlat_256[pSelector->m_selectors[3]];
#endif
	}

#if BASISD_ENABLE_DEBUG_FLAGS
	static void convert_etc1s_to_dxt1_vis(dxt1_block* pDst_block, const endpoint* pEndpoints, const selector* pSelector, bool use_threecolor_blocks)
	{
		convert_etc1s_to_dxt1(pDst_block, pEndpoints, pSelector, use_threecolor_blocks);

		if (g_debug_flags & cDebugFlagVisBC1Sels)
		{
			uint32_t l = dxt1_block::pack_unscaled_color(31, 63, 31);
			uint32_t h = dxt1_block::pack_unscaled_color(0, 0, 0);
			pDst_block->set_low_color(static_cast<uint16_t>(l));
			pDst_block->set_high_color(static_cast<uint16_t>(h));
		}
		else if (g_debug_flags & cDebugFlagVisBC1Endpoints)
		{
			for (uint32_t y = 0; y < 4; y++)
				for (uint32_t x = 0; x < 4; x++)
					pDst_block->set_selector(x, y, (y < 2) ? 0 : 1);
		}
	}
#endif
#endif

#if BASISD_SUPPORT_FXT1
	struct fxt1_block
	{
		union
		{
			struct
			{
				uint64_t m_t00 : 2;
				uint64_t m_t01 : 2;
				uint64_t m_t02 : 2;
				uint64_t m_t03 : 2;
				uint64_t m_t04 : 2;
				uint64_t m_t05 : 2;
				uint64_t m_t06 : 2;
				uint64_t m_t07 : 2;
				uint64_t m_t08 : 2;
				uint64_t m_t09 : 2;
				uint64_t m_t10 : 2;
				uint64_t m_t11 : 2;
				uint64_t m_t12 : 2;
				uint64_t m_t13 : 2;
				uint64_t m_t14 : 2;
				uint64_t m_t15 : 2;
				uint64_t m_t16 : 2;
				uint64_t m_t17 : 2;
				uint64_t m_t18 : 2;
				uint64_t m_t19 : 2;
				uint64_t m_t20 : 2;
				uint64_t m_t21 : 2;
				uint64_t m_t22 : 2;
				uint64_t m_t23 : 2;
				uint64_t m_t24 : 2;
				uint64_t m_t25 : 2;
				uint64_t m_t26 : 2;
				uint64_t m_t27 : 2;
				uint64_t m_t28 : 2;
				uint64_t m_t29 : 2;
				uint64_t m_t30 : 2;
				uint64_t m_t31 : 2;
			} m_lo;
			uint64_t m_lo_bits;
			uint8_t m_sels[8];
		};
		union
		{
			struct
			{
#ifdef BASISU_USE_ORIGINAL_3DFX_FXT1_ENCODING
				uint64_t m_b1 : 5;
				uint64_t m_g1 : 5;
				uint64_t m_r1 : 5;
				uint64_t m_b0 : 5;
				uint64_t m_g0 : 5;
				uint64_t m_r0 : 5;
				uint64_t m_b3 : 5;
				uint64_t m_g3 : 5;
				uint64_t m_r3 : 5;
				uint64_t m_b2 : 5;
				uint64_t m_g2 : 5;
				uint64_t m_r2 : 5;
#else
				uint64_t m_b0 : 5;
				uint64_t m_g0 : 5;
				uint64_t m_r0 : 5;
				uint64_t m_b1 : 5;
				uint64_t m_g1 : 5;
				uint64_t m_r1 : 5;
				uint64_t m_b2 : 5;
				uint64_t m_g2 : 5;
				uint64_t m_r2 : 5;
				uint64_t m_b3 : 5;
				uint64_t m_g3 : 5;
				uint64_t m_r3 : 5;
#endif
				uint64_t m_alpha : 1;
				uint64_t m_glsb : 2;
				uint64_t m_mode : 1;
			} m_hi;
			uint64_t m_hi_bits;
		};
	};

	static uint8_t conv_dxt1_to_fxt1_sels(uint32_t sels)
	{
		static uint8_t s_conv_table[16] = { 0, 3, 1, 2, 12, 15, 13, 14, 4, 7, 5, 6, 8, 11, 9, 10 };
		return s_conv_table[sels & 15] | (s_conv_table[sels >> 4] << 4);
	}

	static void convert_etc1s_to_fxt1(void *pDst, const endpoint *pEndpoints, const selector *pSelectors, uint32_t fxt1_subblock)
	{
		fxt1_block* pBlock = static_cast<fxt1_block*>(pDst);

		// CC_MIXED is basically DXT1 with different encoding tricks.
		// So transcode ETC1S to DXT1, then transcode that to FXT1 which is easy and nearly lossless. 
		// (It's not completely lossless because FXT1 rounds in its color lerps while DXT1 doesn't, but it should be good enough.)
		dxt1_block blk;
		convert_etc1s_to_dxt1(&blk, pEndpoints, pSelectors, false);

		const uint32_t l = blk.get_low_color();
		const uint32_t h = blk.get_high_color();

		color32 color0((l >> 11) & 31, (l >> 5) & 63, l & 31, 255);
		color32 color1((h >> 11) & 31, (h >> 5) & 63, h & 31, 255);

		uint32_t g0 = color0.g & 1;
		uint32_t g1 = color1.g & 1;
		
		color0.g >>= 1;
		color1.g >>= 1;

		blk.m_selectors[0] = conv_dxt1_to_fxt1_sels(blk.m_selectors[0]);
		blk.m_selectors[1] = conv_dxt1_to_fxt1_sels(blk.m_selectors[1]);
		blk.m_selectors[2] = conv_dxt1_to_fxt1_sels(blk.m_selectors[2]);
		blk.m_selectors[3] = conv_dxt1_to_fxt1_sels(blk.m_selectors[3]);
		
		if ((blk.get_selector(0, 0) >> 1) != (g0 ^ g1))
		{
			std::swap(color0, color1);
			std::swap(g0, g1);

			blk.m_selectors[0] ^= 0xFF;
			blk.m_selectors[1] ^= 0xFF;
			blk.m_selectors[2] ^= 0xFF;
			blk.m_selectors[3] ^= 0xFF;
		}

		if (fxt1_subblock == 0)
		{
			pBlock->m_hi.m_mode = 1; 
			pBlock->m_hi.m_alpha = 0;
			pBlock->m_hi.m_glsb = g1 | (g1 << 1);
			pBlock->m_hi.m_r0 = color0.r;
			pBlock->m_hi.m_g0 = color0.g;
			pBlock->m_hi.m_b0 = color0.b;
			pBlock->m_hi.m_r1 = color1.r;
			pBlock->m_hi.m_g1 = color1.g;
			pBlock->m_hi.m_b1 = color1.b;
			pBlock->m_hi.m_r2 = color0.r;
			pBlock->m_hi.m_g2 = color0.g;
			pBlock->m_hi.m_b2 = color0.b;
			pBlock->m_hi.m_r3 = color1.r;
			pBlock->m_hi.m_g3 = color1.g;
			pBlock->m_hi.m_b3 = color1.b;
			pBlock->m_sels[0] = blk.m_selectors[0];
			pBlock->m_sels[1] = blk.m_selectors[1];
			pBlock->m_sels[2] = blk.m_selectors[2];
			pBlock->m_sels[3] = blk.m_selectors[3];

			static const uint8_t s_border_dup[4] = { 0, 85, 170, 255 };
			pBlock->m_sels[4] = s_border_dup[blk.m_selectors[0] >> 6];
			pBlock->m_sels[5] = s_border_dup[blk.m_selectors[1] >> 6];
			pBlock->m_sels[6] = s_border_dup[blk.m_selectors[2] >> 6];
			pBlock->m_sels[7] = s_border_dup[blk.m_selectors[3] >> 6];
		}
		else
		{
			pBlock->m_hi.m_glsb = (pBlock->m_hi.m_glsb & 1) | (g1 << 1);
			pBlock->m_hi.m_r2 = color0.r;
			pBlock->m_hi.m_g2 = color0.g;
			pBlock->m_hi.m_b2 = color0.b;
			pBlock->m_hi.m_r3 = color1.r;
			pBlock->m_hi.m_g3 = color1.g;
			pBlock->m_hi.m_b3 = color1.b;
			pBlock->m_sels[4] = blk.m_selectors[0];
			pBlock->m_sels[5] = blk.m_selectors[1];
			pBlock->m_sels[6] = blk.m_selectors[2];
			pBlock->m_sels[7] = blk.m_selectors[3];
		}
	}
#endif // BASISD_SUPPORT_FXT1
#if BASISD_SUPPORT_DXT5A
	static dxt_selector_range s_dxt5a_selector_ranges[] =
	{
		{ 0, 3 },

		{ 1, 3 },
		{ 0, 2 },

		{ 1, 2 },
	};

	const uint32_t NUM_DXT5A_SELECTOR_RANGES = sizeof(s_dxt5a_selector_ranges) / sizeof(s_dxt5a_selector_ranges[0]);

	struct etc1_g_to_dxt5a_conversion
	{
		uint8_t m_lo, m_hi;
		uint16_t m_trans;
	};

	static etc1_g_to_dxt5a_conversion g_etc1_g_to_dxt5a[32 * 8][NUM_DXT5A_SELECTOR_RANGES] =
	{
		{ { 8, 0, 393 },{ 8, 0, 392 },{ 2, 0, 9 },{ 2, 0, 8 }, }, { { 6, 16, 710 },{ 16, 6, 328 },{ 0, 10, 96 },{ 10, 6, 8 }, },
		{ { 28, 5, 1327 },{ 24, 14, 328 },{ 8, 18, 96 },{ 18, 14, 8 }, }, { { 36, 13, 1327 },{ 32, 22, 328 },{ 16, 26, 96 },{ 26, 22, 8 }, },
		{ { 45, 22, 1327 },{ 41, 31, 328 },{ 25, 35, 96 },{ 35, 31, 8 }, }, { { 53, 30, 1327 },{ 49, 39, 328 },{ 33, 43, 96 },{ 43, 39, 8 }, },
		{ { 61, 38, 1327 },{ 57, 47, 328 },{ 41, 51, 96 },{ 51, 47, 8 }, }, { { 69, 46, 1327 },{ 65, 55, 328 },{ 49, 59, 96 },{ 59, 55, 8 }, },
		{ { 78, 55, 1327 },{ 74, 64, 328 },{ 58, 68, 96 },{ 68, 64, 8 }, }, { { 86, 63, 1327 },{ 82, 72, 328 },{ 66, 76, 96 },{ 76, 72, 8 }, },
		{ { 94, 71, 1327 },{ 90, 80, 328 },{ 74, 84, 96 },{ 84, 80, 8 }, }, { { 102, 79, 1327 },{ 98, 88, 328 },{ 82, 92, 96 },{ 92, 88, 8 }, },
		{ { 111, 88, 1327 },{ 107, 97, 328 },{ 91, 101, 96 },{ 101, 97, 8 }, }, { { 119, 96, 1327 },{ 115, 105, 328 },{ 99, 109, 96 },{ 109, 105, 8 }, },
		{ { 127, 104, 1327 },{ 123, 113, 328 },{ 107, 117, 96 },{ 117, 113, 8 }, }, { { 135, 112, 1327 },{ 131, 121, 328 },{ 115, 125, 96 },{ 125, 121, 8 }, },
		{ { 144, 121, 1327 },{ 140, 130, 328 },{ 124, 134, 96 },{ 134, 130, 8 }, }, { { 152, 129, 1327 },{ 148, 138, 328 },{ 132, 142, 96 },{ 142, 138, 8 }, },
		{ { 160, 137, 1327 },{ 156, 146, 328 },{ 140, 150, 96 },{ 150, 146, 8 }, }, { { 168, 145, 1327 },{ 164, 154, 328 },{ 148, 158, 96 },{ 158, 154, 8 }, },
		{ { 177, 154, 1327 },{ 173, 163, 328 },{ 157, 167, 96 },{ 167, 163, 8 }, }, { { 185, 162, 1327 },{ 181, 171, 328 },{ 165, 175, 96 },{ 175, 171, 8 }, },
		{ { 193, 170, 1327 },{ 189, 179, 328 },{ 173, 183, 96 },{ 183, 179, 8 }, }, { { 201, 178, 1327 },{ 197, 187, 328 },{ 181, 191, 96 },{ 191, 187, 8 }, },
		{ { 210, 187, 1327 },{ 206, 196, 328 },{ 190, 200, 96 },{ 200, 196, 8 }, }, { { 218, 195, 1327 },{ 214, 204, 328 },{ 198, 208, 96 },{ 208, 204, 8 }, },
		{ { 226, 203, 1327 },{ 222, 212, 328 },{ 206, 216, 96 },{ 216, 212, 8 }, }, { { 234, 211, 1327 },{ 230, 220, 328 },{ 214, 224, 96 },{ 224, 220, 8 }, },
		{ { 243, 220, 1327 },{ 239, 229, 328 },{ 223, 233, 96 },{ 233, 229, 8 }, }, { { 251, 228, 1327 },{ 247, 237, 328 },{ 231, 241, 96 },{ 241, 237, 8 }, },
		{ { 239, 249, 3680 },{ 245, 249, 3648 },{ 239, 249, 96 },{ 249, 245, 8 }, }, { { 247, 253, 4040 },{ 255, 253, 8 },{ 247, 253, 456 },{ 255, 253, 8 }, },
		{ { 5, 17, 566 },{ 5, 17, 560 },{ 5, 0, 9 },{ 5, 0, 8 }, }, { { 25, 0, 313 },{ 25, 3, 328 },{ 13, 0, 49 },{ 13, 3, 8 }, },
		{ { 39, 0, 1329 },{ 33, 11, 328 },{ 11, 21, 70 },{ 21, 11, 8 }, }, { { 47, 7, 1329 },{ 41, 19, 328 },{ 29, 7, 33 },{ 29, 19, 8 }, },
		{ { 50, 11, 239 },{ 50, 28, 328 },{ 38, 16, 33 },{ 38, 28, 8 }, }, { { 92, 13, 2423 },{ 58, 36, 328 },{ 46, 24, 33 },{ 46, 36, 8 }, },
		{ { 100, 21, 2423 },{ 66, 44, 328 },{ 54, 32, 33 },{ 54, 44, 8 }, }, { { 86, 7, 1253 },{ 74, 52, 328 },{ 62, 40, 33 },{ 62, 52, 8 }, },
		{ { 95, 16, 1253 },{ 83, 61, 328 },{ 71, 49, 33 },{ 71, 61, 8 }, }, { { 103, 24, 1253 },{ 91, 69, 328 },{ 79, 57, 33 },{ 79, 69, 8 }, },
		{ { 111, 32, 1253 },{ 99, 77, 328 },{ 87, 65, 33 },{ 87, 77, 8 }, }, { { 119, 40, 1253 },{ 107, 85, 328 },{ 95, 73, 33 },{ 95, 85, 8 }, },
		{ { 128, 49, 1253 },{ 116, 94, 328 },{ 104, 82, 33 },{ 104, 94, 8 }, }, { { 136, 57, 1253 },{ 124, 102, 328 },{ 112, 90, 33 },{ 112, 102, 8 }, },
		{ { 144, 65, 1253 },{ 132, 110, 328 },{ 120, 98, 33 },{ 120, 110, 8 }, }, { { 152, 73, 1253 },{ 140, 118, 328 },{ 128, 106, 33 },{ 128, 118, 8 }, },
		{ { 161, 82, 1253 },{ 149, 127, 328 },{ 137, 115, 33 },{ 137, 127, 8 }, }, { { 169, 90, 1253 },{ 157, 135, 328 },{ 145, 123, 33 },{ 145, 135, 8 }, },
		{ { 177, 98, 1253 },{ 165, 143, 328 },{ 153, 131, 33 },{ 153, 143, 8 }, }, { { 185, 106, 1253 },{ 173, 151, 328 },{ 161, 139, 33 },{ 161, 151, 8 }, },
		{ { 194, 115, 1253 },{ 182, 160, 328 },{ 170, 148, 33 },{ 170, 160, 8 }, }, { { 202, 123, 1253 },{ 190, 168, 328 },{ 178, 156, 33 },{ 178, 168, 8 }, },
		{ { 210, 131, 1253 },{ 198, 176, 328 },{ 186, 164, 33 },{ 186, 176, 8 }, }, { { 218, 139, 1253 },{ 206, 184, 328 },{ 194, 172, 33 },{ 194, 184, 8 }, },
		{ { 227, 148, 1253 },{ 215, 193, 328 },{ 203, 181, 33 },{ 203, 193, 8 }, }, { { 235, 156, 1253 },{ 223, 201, 328 },{ 211, 189, 33 },{ 211, 201, 8 }, },
		{ { 243, 164, 1253 },{ 231, 209, 328 },{ 219, 197, 33 },{ 219, 209, 8 }, }, { { 183, 239, 867 },{ 239, 217, 328 },{ 227, 205, 33 },{ 227, 217, 8 }, },
		{ { 254, 214, 1329 },{ 248, 226, 328 },{ 236, 214, 33 },{ 236, 226, 8 }, }, { { 222, 244, 3680 },{ 234, 244, 3648 },{ 244, 222, 33 },{ 244, 234, 8 }, },
		{ { 230, 252, 3680 },{ 242, 252, 3648 },{ 252, 230, 33 },{ 252, 242, 8 }, }, { { 238, 250, 4040 },{ 255, 250, 8 },{ 238, 250, 456 },{ 255, 250, 8 }, },
		{ { 9, 29, 566 },{ 9, 29, 560 },{ 9, 0, 9 },{ 9, 0, 8 }, }, { { 17, 37, 566 },{ 17, 37, 560 },{ 17, 0, 9 },{ 17, 0, 8 }, },
		{ { 45, 0, 313 },{ 45, 0, 312 },{ 25, 0, 49 },{ 25, 7, 8 }, }, { { 14, 63, 2758 },{ 5, 53, 784 },{ 15, 33, 70 },{ 33, 15, 8 }, },
		{ { 71, 6, 1329 },{ 72, 4, 1328 },{ 42, 4, 33 },{ 42, 24, 8 }, }, { { 70, 3, 239 },{ 70, 2, 232 },{ 50, 12, 33 },{ 50, 32, 8 }, },
		{ { 0, 98, 2842 },{ 78, 10, 232 },{ 58, 20, 33 },{ 58, 40, 8 }, }, { { 97, 27, 1329 },{ 86, 18, 232 },{ 66, 28, 33 },{ 66, 48, 8 }, },
		{ { 0, 94, 867 },{ 95, 27, 232 },{ 75, 37, 33 },{ 75, 57, 8 }, }, { { 8, 102, 867 },{ 103, 35, 232 },{ 83, 45, 33 },{ 83, 65, 8 }, },
		{ { 12, 112, 867 },{ 111, 43, 232 },{ 91, 53, 33 },{ 91, 73, 8 }, }, { { 139, 2, 1253 },{ 119, 51, 232 },{ 99, 61, 33 },{ 99, 81, 8 }, },
		{ { 148, 13, 1253 },{ 128, 60, 232 },{ 108, 70, 33 },{ 108, 90, 8 }, }, { { 156, 21, 1253 },{ 136, 68, 232 },{ 116, 78, 33 },{ 116, 98, 8 }, },
		{ { 164, 29, 1253 },{ 144, 76, 232 },{ 124, 86, 33 },{ 124, 106, 8 }, }, { { 172, 37, 1253 },{ 152, 84, 232 },{ 132, 94, 33 },{ 132, 114, 8 }, },
		{ { 181, 46, 1253 },{ 161, 93, 232 },{ 141, 103, 33 },{ 141, 123, 8 }, }, { { 189, 54, 1253 },{ 169, 101, 232 },{ 149, 111, 33 },{ 149, 131, 8 }, },
		{ { 197, 62, 1253 },{ 177, 109, 232 },{ 157, 119, 33 },{ 157, 139, 8 }, }, { { 205, 70, 1253 },{ 185, 117, 232 },{ 165, 127, 33 },{ 165, 147, 8 }, },
		{ { 214, 79, 1253 },{ 194, 126, 232 },{ 174, 136, 33 },{ 174, 156, 8 }, }, { { 222, 87, 1253 },{ 202, 134, 232 },{ 182, 144, 33 },{ 182, 164, 8 }, },
		{ { 230, 95, 1253 },{ 210, 142, 232 },{ 190, 152, 33 },{ 190, 172, 8 }, }, { { 238, 103, 1253 },{ 218, 150, 232 },{ 198, 160, 33 },{ 198, 180, 8 }, },
		{ { 247, 112, 1253 },{ 227, 159, 232 },{ 207, 169, 33 },{ 207, 189, 8 }, }, { { 255, 120, 1253 },{ 235, 167, 232 },{ 215, 177, 33 },{ 215, 197, 8 }, },
		{ { 146, 243, 867 },{ 243, 175, 232 },{ 223, 185, 33 },{ 223, 205, 8 }, }, { { 184, 231, 3682 },{ 203, 251, 784 },{ 231, 193, 33 },{ 231, 213, 8 }, },
		{ { 193, 240, 3682 },{ 222, 240, 3648 },{ 240, 202, 33 },{ 240, 222, 8 }, }, { { 255, 210, 169 },{ 230, 248, 3648 },{ 248, 210, 33 },{ 248, 230, 8 }, },
		{ { 218, 238, 4040 },{ 255, 238, 8 },{ 218, 238, 456 },{ 255, 238, 8 }, }, { { 226, 246, 4040 },{ 255, 246, 8 },{ 226, 246, 456 },{ 255, 246, 8 }, },
		{ { 13, 42, 566 },{ 13, 42, 560 },{ 13, 0, 9 },{ 13, 0, 8 }, }, { { 50, 0, 329 },{ 50, 0, 328 },{ 21, 0, 9 },{ 21, 0, 8 }, },
		{ { 29, 58, 566 },{ 67, 2, 1352 },{ 3, 29, 70 },{ 29, 3, 8 }, }, { { 10, 79, 2758 },{ 76, 11, 1352 },{ 11, 37, 70 },{ 37, 11, 8 }, },
		{ { 7, 75, 790 },{ 7, 75, 784 },{ 20, 46, 70 },{ 46, 20, 8 }, }, { { 15, 83, 790 },{ 97, 1, 1328 },{ 28, 54, 70 },{ 54, 28, 8 }, },
		{ { 101, 7, 1329 },{ 105, 9, 1328 },{ 62, 0, 39 },{ 62, 36, 8 }, }, { { 99, 1, 239 },{ 99, 3, 232 },{ 1, 71, 98 },{ 70, 44, 8 }, },
		{ { 107, 11, 239 },{ 108, 12, 232 },{ 10, 80, 98 },{ 79, 53, 8 }, }, { { 115, 19, 239 },{ 116, 20, 232 },{ 18, 88, 98 },{ 87, 61, 8 }, },
		{ { 123, 27, 239 },{ 124, 28, 232 },{ 26, 96, 98 },{ 95, 69, 8 }, }, { { 131, 35, 239 },{ 132, 36, 232 },{ 34, 104, 98 },{ 103, 77, 8 }, },
		{ { 140, 44, 239 },{ 141, 45, 232 },{ 43, 113, 98 },{ 112, 86, 8 }, }, { { 148, 52, 239 },{ 149, 53, 232 },{ 51, 121, 98 },{ 120, 94, 8 }, },
		{ { 156, 60, 239 },{ 157, 61, 232 },{ 59, 129, 98 },{ 128, 102, 8 }, }, { { 164, 68, 239 },{ 165, 69, 232 },{ 67, 137, 98 },{ 136, 110, 8 }, },
		{ { 173, 77, 239 },{ 174, 78, 232 },{ 76, 146, 98 },{ 145, 119, 8 }, }, { { 181, 85, 239 },{ 182, 86, 232 },{ 84, 154, 98 },{ 153, 127, 8 }, },
		{ { 189, 93, 239 },{ 190, 94, 232 },{ 92, 162, 98 },{ 161, 135, 8 }, }, { { 197, 101, 239 },{ 198, 102, 232 },{ 100, 170, 98 },{ 169, 143, 8 }, },
		{ { 206, 110, 239 },{ 207, 111, 232 },{ 109, 179, 98 },{ 178, 152, 8 }, }, { { 214, 118, 239 },{ 215, 119, 232 },{ 117, 187, 98 },{ 186, 160, 8 }, },
		{ { 222, 126, 239 },{ 223, 127, 232 },{ 125, 195, 98 },{ 194, 168, 8 }, }, { { 230, 134, 239 },{ 231, 135, 232 },{ 133, 203, 98 },{ 202, 176, 8 }, },
		{ { 239, 143, 239 },{ 240, 144, 232 },{ 142, 212, 98 },{ 211, 185, 8 }, }, { { 247, 151, 239 },{ 180, 248, 784 },{ 150, 220, 98 },{ 219, 193, 8 }, },
		{ { 159, 228, 3682 },{ 201, 227, 3648 },{ 158, 228, 98 },{ 227, 201, 8 }, }, { { 181, 249, 3928 },{ 209, 235, 3648 },{ 166, 236, 98 },{ 235, 209, 8 }, },
		{ { 255, 189, 169 },{ 218, 244, 3648 },{ 175, 245, 98 },{ 244, 218, 8 }, }, { { 197, 226, 4040 },{ 226, 252, 3648 },{ 183, 253, 98 },{ 252, 226, 8 }, },
		{ { 205, 234, 4040 },{ 255, 234, 8 },{ 205, 234, 456 },{ 255, 234, 8 }, }, { { 213, 242, 4040 },{ 255, 242, 8 },{ 213, 242, 456 },{ 255, 242, 8 }, },
		{ { 18, 60, 566 },{ 18, 60, 560 },{ 18, 0, 9 },{ 18, 0, 8 }, }, { { 26, 68, 566 },{ 26, 68, 560 },{ 26, 0, 9 },{ 26, 0, 8 }, },
		{ { 34, 76, 566 },{ 34, 76, 560 },{ 34, 0, 9 },{ 34, 0, 8 }, }, { { 5, 104, 2758 },{ 98, 5, 1352 },{ 42, 0, 57 },{ 42, 6, 8 }, },
		{ { 92, 0, 313 },{ 93, 1, 312 },{ 15, 51, 70 },{ 51, 15, 8 }, }, { { 3, 101, 790 },{ 3, 101, 784 },{ 0, 59, 88 },{ 59, 23, 8 }, },
		{ { 14, 107, 790 },{ 11, 109, 784 },{ 31, 67, 70 },{ 67, 31, 8 }, }, { { 19, 117, 790 },{ 19, 117, 784 },{ 39, 75, 70 },{ 75, 39, 8 }, },
		{ { 28, 126, 790 },{ 28, 126, 784 },{ 83, 5, 33 },{ 84, 48, 8 }, }, { { 132, 0, 239 },{ 36, 134, 784 },{ 91, 13, 33 },{ 92, 56, 8 }, },
		{ { 142, 4, 239 },{ 44, 142, 784 },{ 99, 21, 33 },{ 100, 64, 8 }, }, { { 150, 12, 239 },{ 52, 150, 784 },{ 107, 29, 33 },{ 108, 72, 8 }, },
		{ { 159, 21, 239 },{ 61, 159, 784 },{ 116, 38, 33 },{ 117, 81, 8 }, }, { { 167, 29, 239 },{ 69, 167, 784 },{ 124, 46, 33 },{ 125, 89, 8 }, },
		{ { 175, 37, 239 },{ 77, 175, 784 },{ 132, 54, 33 },{ 133, 97, 8 }, }, { { 183, 45, 239 },{ 85, 183, 784 },{ 140, 62, 33 },{ 141, 105, 8 }, },
		{ { 192, 54, 239 },{ 94, 192, 784 },{ 149, 71, 33 },{ 150, 114, 8 }, }, { { 200, 62, 239 },{ 102, 200, 784 },{ 157, 79, 33 },{ 158, 122, 8 }, },
		{ { 208, 70, 239 },{ 110, 208, 784 },{ 165, 87, 33 },{ 166, 130, 8 }, }, { { 216, 78, 239 },{ 118, 216, 784 },{ 173, 95, 33 },{ 174, 138, 8 }, },
		{ { 225, 87, 239 },{ 127, 225, 784 },{ 182, 104, 33 },{ 183, 147, 8 }, }, { { 233, 95, 239 },{ 135, 233, 784 },{ 190, 112, 33 },{ 191, 155, 8 }, },
		{ { 241, 103, 239 },{ 143, 241, 784 },{ 198, 120, 33 },{ 199, 163, 8 }, }, { { 111, 208, 3682 },{ 151, 249, 784 },{ 206, 128, 33 },{ 207, 171, 8 }, },
		{ { 120, 217, 3682 },{ 180, 216, 3648 },{ 215, 137, 33 },{ 216, 180, 8 }, }, { { 128, 225, 3682 },{ 188, 224, 3648 },{ 223, 145, 33 },{ 224, 188, 8 }, },
		{ { 155, 253, 3928 },{ 196, 232, 3648 },{ 231, 153, 33 },{ 232, 196, 8 }, }, { { 144, 241, 3682 },{ 204, 240, 3648 },{ 239, 161, 33 },{ 240, 204, 8 }, },
		{ { 153, 250, 3682 },{ 213, 249, 3648 },{ 248, 170, 33 },{ 249, 213, 8 }, }, { { 179, 221, 4040 },{ 255, 221, 8 },{ 179, 221, 456 },{ 255, 221, 8 }, },
		{ { 187, 229, 4040 },{ 255, 229, 8 },{ 187, 229, 456 },{ 255, 229, 8 }, }, { { 195, 237, 4040 },{ 255, 237, 8 },{ 195, 237, 456 },{ 255, 237, 8 }, },
		{ { 24, 80, 566 },{ 24, 80, 560 },{ 24, 0, 9 },{ 24, 0, 8 }, }, { { 32, 88, 566 },{ 32, 88, 560 },{ 32, 0, 9 },{ 32, 0, 8 }, },
		{ { 40, 96, 566 },{ 40, 96, 560 },{ 40, 0, 9 },{ 40, 0, 8 }, }, { { 48, 104, 566 },{ 48, 104, 560 },{ 48, 0, 9 },{ 48, 0, 8 }, },
		{ { 9, 138, 2758 },{ 130, 7, 1352 },{ 9, 57, 70 },{ 57, 9, 8 }, }, { { 119, 0, 313 },{ 120, 0, 312 },{ 17, 65, 70 },{ 65, 17, 8 }, },
		{ { 0, 128, 784 },{ 128, 6, 312 },{ 25, 73, 70 },{ 73, 25, 8 }, }, { { 6, 137, 790 },{ 5, 136, 784 },{ 33, 81, 70 },{ 81, 33, 8 }, },
		{ { 42, 171, 2758 },{ 14, 145, 784 },{ 42, 90, 70 },{ 90, 42, 8 }, }, { { 50, 179, 2758 },{ 22, 153, 784 },{ 50, 98, 70 },{ 98, 50, 8 }, },
		{ { 58, 187, 2758 },{ 30, 161, 784 },{ 58, 106, 70 },{ 106, 58, 8 }, }, { { 191, 18, 1329 },{ 38, 169, 784 },{ 112, 9, 33 },{ 114, 66, 8 }, },
		{ { 176, 0, 239 },{ 47, 178, 784 },{ 121, 18, 33 },{ 123, 75, 8 }, }, { { 187, 1, 239 },{ 55, 186, 784 },{ 129, 26, 33 },{ 131, 83, 8 }, },
		{ { 195, 10, 239 },{ 63, 194, 784 },{ 137, 34, 33 },{ 139, 91, 8 }, }, { { 203, 18, 239 },{ 71, 202, 784 },{ 145, 42, 33 },{ 147, 99, 8 }, },
		{ { 212, 27, 239 },{ 80, 211, 784 },{ 154, 51, 33 },{ 156, 108, 8 }, }, { { 220, 35, 239 },{ 88, 219, 784 },{ 162, 59, 33 },{ 164, 116, 8 }, },
		{ { 228, 43, 239 },{ 96, 227, 784 },{ 170, 67, 33 },{ 172, 124, 8 }, }, { { 236, 51, 239 },{ 104, 235, 784 },{ 178, 75, 33 },{ 180, 132, 8 }, },
		{ { 245, 60, 239 },{ 113, 244, 784 },{ 187, 84, 33 },{ 189, 141, 8 }, }, { { 91, 194, 3680 },{ 149, 197, 3648 },{ 195, 92, 33 },{ 197, 149, 8 }, },
		{ { 99, 202, 3680 },{ 157, 205, 3648 },{ 203, 100, 33 },{ 205, 157, 8 }, }, { { 107, 210, 3680 },{ 165, 213, 3648 },{ 211, 108, 33 },{ 213, 165, 8 }, },
		{ { 119, 249, 3928 },{ 174, 222, 3648 },{ 220, 117, 33 },{ 222, 174, 8 }, }, { { 127, 255, 856 },{ 182, 230, 3648 },{ 228, 125, 33 },{ 230, 182, 8 }, },
		{ { 255, 135, 169 },{ 190, 238, 3648 },{ 236, 133, 33 },{ 238, 190, 8 }, }, { { 140, 243, 3680 },{ 198, 246, 3648 },{ 244, 141, 33 },{ 246, 198, 8 }, },
		{ { 151, 207, 4040 },{ 255, 207, 8 },{ 151, 207, 456 },{ 255, 207, 8 }, }, { { 159, 215, 4040 },{ 255, 215, 8 },{ 159, 215, 456 },{ 255, 215, 8 }, },
		{ { 167, 223, 4040 },{ 255, 223, 8 },{ 167, 223, 456 },{ 255, 223, 8 }, }, { { 175, 231, 4040 },{ 255, 231, 8 },{ 175, 231, 456 },{ 255, 231, 8 }, },
		{ { 33, 106, 566 },{ 33, 106, 560 },{ 33, 0, 9 },{ 33, 0, 8 }, }, { { 41, 114, 566 },{ 41, 114, 560 },{ 41, 0, 9 },{ 41, 0, 8 }, },
		{ { 49, 122, 566 },{ 49, 122, 560 },{ 49, 0, 9 },{ 49, 0, 8 }, }, { { 57, 130, 566 },{ 57, 130, 560 },{ 57, 0, 9 },{ 57, 0, 8 }, },
		{ { 66, 139, 566 },{ 66, 139, 560 },{ 66, 0, 9 },{ 66, 0, 8 }, }, { { 74, 147, 566 },{ 170, 7, 1352 },{ 8, 74, 70 },{ 74, 8, 8 }, },
		{ { 152, 0, 313 },{ 178, 15, 1352 },{ 0, 82, 80 },{ 82, 16, 8 }, }, { { 162, 0, 313 },{ 186, 23, 1352 },{ 24, 90, 70 },{ 90, 24, 8 }, },
		{ { 0, 171, 784 },{ 195, 32, 1352 },{ 33, 99, 70 },{ 99, 33, 8 }, }, { { 6, 179, 790 },{ 203, 40, 1352 },{ 41, 107, 70 },{ 107, 41, 8 }, },
		{ { 15, 187, 790 },{ 211, 48, 1352 },{ 115, 0, 41 },{ 115, 49, 8 }, }, { { 61, 199, 710 },{ 219, 56, 1352 },{ 57, 123, 70 },{ 123, 57, 8 }, },
		{ { 70, 208, 710 },{ 228, 65, 1352 },{ 66, 132, 70 },{ 132, 66, 8 }, }, { { 78, 216, 710 },{ 236, 73, 1352 },{ 74, 140, 70 },{ 140, 74, 8 }, },
		{ { 86, 224, 710 },{ 244, 81, 1352 },{ 145, 7, 33 },{ 148, 82, 8 }, }, { { 222, 8, 233 },{ 252, 89, 1352 },{ 153, 15, 33 },{ 156, 90, 8 }, },
		{ { 235, 0, 239 },{ 241, 101, 328 },{ 166, 6, 39 },{ 165, 99, 8 }, }, { { 32, 170, 3680 },{ 249, 109, 328 },{ 0, 175, 98 },{ 173, 107, 8 }, },
		{ { 40, 178, 3680 },{ 115, 181, 3648 },{ 8, 183, 98 },{ 181, 115, 8 }, }, { { 48, 186, 3680 },{ 123, 189, 3648 },{ 16, 191, 98 },{ 189, 123, 8 }, },
		{ { 57, 195, 3680 },{ 132, 198, 3648 },{ 25, 200, 98 },{ 198, 132, 8 }, }, { { 67, 243, 3928 },{ 140, 206, 3648 },{ 33, 208, 98 },{ 206, 140, 8 }, },
		{ { 76, 251, 3928 },{ 148, 214, 3648 },{ 41, 216, 98 },{ 214, 148, 8 }, }, { { 86, 255, 856 },{ 156, 222, 3648 },{ 49, 224, 98 },{ 222, 156, 8 }, },
		{ { 255, 93, 169 },{ 165, 231, 3648 },{ 58, 233, 98 },{ 231, 165, 8 }, }, { { 98, 236, 3680 },{ 173, 239, 3648 },{ 66, 241, 98 },{ 239, 173, 8 }, },
		{ { 108, 181, 4040 },{ 181, 247, 3648 },{ 74, 249, 98 },{ 247, 181, 8 }, }, { { 116, 189, 4040 },{ 255, 189, 8 },{ 116, 189, 456 },{ 255, 189, 8 }, },
		{ { 125, 198, 4040 },{ 255, 198, 8 },{ 125, 198, 456 },{ 255, 198, 8 }, }, { { 133, 206, 4040 },{ 255, 206, 8 },{ 133, 206, 456 },{ 255, 206, 8 }, },
		{ { 141, 214, 4040 },{ 255, 214, 8 },{ 141, 214, 456 },{ 255, 214, 8 }, }, { { 149, 222, 4040 },{ 255, 222, 8 },{ 149, 222, 456 },{ 255, 222, 8 }, },
		{ { 47, 183, 566 },{ 47, 183, 560 },{ 47, 0, 9 },{ 47, 0, 8 }, }, { { 55, 191, 566 },{ 55, 191, 560 },{ 55, 0, 9 },{ 55, 0, 8 }, },
		{ { 63, 199, 566 },{ 63, 199, 560 },{ 63, 0, 9 },{ 63, 0, 8 }, }, { { 71, 207, 566 },{ 71, 207, 560 },{ 71, 0, 9 },{ 71, 0, 8 }, },
		{ { 80, 216, 566 },{ 80, 216, 560 },{ 80, 0, 9 },{ 80, 0, 8 }, }, { { 88, 224, 566 },{ 88, 224, 560 },{ 88, 0, 9 },{ 88, 0, 8 }, },
		{ { 3, 233, 710 },{ 3, 233, 704 },{ 2, 96, 70 },{ 96, 2, 8 }, }, { { 11, 241, 710 },{ 11, 241, 704 },{ 10, 104, 70 },{ 104, 10, 8 }, },
		{ { 20, 250, 710 },{ 20, 250, 704 },{ 19, 113, 70 },{ 113, 19, 8 }, }, { { 27, 121, 3654 },{ 27, 121, 3648 },{ 27, 121, 70 },{ 121, 27, 8 }, },
		{ { 35, 129, 3654 },{ 35, 129, 3648 },{ 35, 129, 70 },{ 129, 35, 8 }, }, { { 43, 137, 3654 },{ 43, 137, 3648 },{ 43, 137, 70 },{ 137, 43, 8 }, },
		{ { 52, 146, 3654 },{ 52, 146, 3648 },{ 52, 146, 70 },{ 146, 52, 8 }, }, { { 60, 154, 3654 },{ 60, 154, 3648 },{ 60, 154, 70 },{ 154, 60, 8 }, },
		{ { 68, 162, 3654 },{ 68, 162, 3648 },{ 68, 162, 70 },{ 162, 68, 8 }, }, { { 76, 170, 3654 },{ 76, 170, 3648 },{ 76, 170, 70 },{ 170, 76, 8 }, },
		{ { 85, 179, 3654 },{ 85, 179, 3648 },{ 85, 179, 70 },{ 179, 85, 8 }, }, { { 93, 187, 3654 },{ 93, 187, 3648 },{ 93, 187, 70 },{ 187, 93, 8 }, },
		{ { 101, 195, 3654 },{ 101, 195, 3648 },{ 101, 195, 70 },{ 195, 101, 8 }, }, { { 109, 203, 3654 },{ 109, 203, 3648 },{ 109, 203, 70 },{ 203, 109, 8 }, },
		{ { 118, 212, 3654 },{ 118, 212, 3648 },{ 118, 212, 70 },{ 212, 118, 8 }, }, { { 126, 220, 3654 },{ 126, 220, 3648 },{ 126, 220, 70 },{ 220, 126, 8 }, },
		{ { 134, 228, 3654 },{ 134, 228, 3648 },{ 134, 228, 70 },{ 228, 134, 8 }, }, { { 5, 236, 3680 },{ 142, 236, 3648 },{ 5, 236, 96 },{ 236, 142, 8 }, },
		{ { 14, 245, 3680 },{ 151, 245, 3648 },{ 14, 245, 96 },{ 245, 151, 8 }, }, { { 23, 159, 4040 },{ 159, 253, 3648 },{ 23, 159, 456 },{ 253, 159, 8 }, },
		{ { 31, 167, 4040 },{ 255, 167, 8 },{ 31, 167, 456 },{ 255, 167, 8 }, }, { { 39, 175, 4040 },{ 255, 175, 8 },{ 39, 175, 456 },{ 255, 175, 8 }, },
		{ { 48, 184, 4040 },{ 255, 184, 8 },{ 48, 184, 456 },{ 255, 184, 8 }, }, { { 56, 192, 4040 },{ 255, 192, 8 },{ 56, 192, 456 },{ 255, 192, 8 }, },
		{ { 64, 200, 4040 },{ 255, 200, 8 },{ 64, 200, 456 },{ 255, 200, 8 }, },{ { 72, 208, 4040 },{ 255, 208, 8 },{ 72, 208, 456 },{ 255, 208, 8 }, },

	};

	struct dxt5a_block
	{
		uint8_t m_endpoints[2];

		enum { cTotalSelectorBytes = 6 };
		uint8_t m_selectors[cTotalSelectorBytes];

		inline void clear()
		{
			basisu::clear_obj(*this);
		}

		inline uint32_t get_low_alpha() const
		{
			return m_endpoints[0];
		}

		inline uint32_t get_high_alpha() const
		{
			return m_endpoints[1];
		}

		inline void set_low_alpha(uint32_t i)
		{
			assert(i <= UINT8_MAX);
			m_endpoints[0] = static_cast<uint8_t>(i);
		}

		inline void set_high_alpha(uint32_t i)
		{
			assert(i <= UINT8_MAX);
			m_endpoints[1] = static_cast<uint8_t>(i);
		}

		inline bool is_alpha6_block() const { return get_low_alpha() <= get_high_alpha(); }

		uint32_t get_endpoints_as_word() const { return m_endpoints[0] | (m_endpoints[1] << 8); }
		uint32_t get_selectors_as_word(uint32_t index) { assert(index < 3); return m_selectors[index * 2] | (m_selectors[index * 2 + 1] << 8); }

		inline uint32_t get_selector(uint32_t x, uint32_t y) const
		{
			assert((x < 4U) && (y < 4U));

			uint32_t selector_index = (y * 4) + x;
			uint32_t bit_index = selector_index * cDXT5SelectorBits;

			uint32_t byte_index = bit_index >> 3;
			uint32_t bit_ofs = bit_index & 7;

			uint32_t v = m_selectors[byte_index];
			if (byte_index < (cTotalSelectorBytes - 1))
				v |= (m_selectors[byte_index + 1] << 8);

			return (v >> bit_ofs) & 7;
		}

		inline void set_selector(uint32_t x, uint32_t y, uint32_t val)
		{
			assert((x < 4U) && (y < 4U) && (val < 8U));

			uint32_t selector_index = (y * 4) + x;
			uint32_t bit_index = selector_index * cDXT5SelectorBits;

			uint32_t byte_index = bit_index >> 3;
			uint32_t bit_ofs = bit_index & 7;

			uint32_t v = m_selectors[byte_index];
			if (byte_index < (cTotalSelectorBytes - 1))
				v |= (m_selectors[byte_index + 1] << 8);

			v &= (~(7 << bit_ofs));
			v |= (val << bit_ofs);

			m_selectors[byte_index] = static_cast<uint8_t>(v);
			if (byte_index < (cTotalSelectorBytes - 1))
				m_selectors[byte_index + 1] = static_cast<uint8_t>(v >> 8);
		}

		enum { cMaxSelectorValues = 8 };

		static uint32_t get_block_values6(color32* pDst, uint32_t l, uint32_t h)
		{
			pDst[0].a = static_cast<uint8_t>(l);
			pDst[1].a = static_cast<uint8_t>(h);
			pDst[2].a = static_cast<uint8_t>((l * 4 + h) / 5);
			pDst[3].a = static_cast<uint8_t>((l * 3 + h * 2) / 5);
			pDst[4].a = static_cast<uint8_t>((l * 2 + h * 3) / 5);
			pDst[5].a = static_cast<uint8_t>((l + h * 4) / 5);
			pDst[6].a = 0;
			pDst[7].a = 255;
			return 6;
		}

		static uint32_t get_block_values8(color32* pDst, uint32_t l, uint32_t h)
		{
			pDst[0].a = static_cast<uint8_t>(l);
			pDst[1].a = static_cast<uint8_t>(h);
			pDst[2].a = static_cast<uint8_t>((l * 6 + h) / 7);
			pDst[3].a = static_cast<uint8_t>((l * 5 + h * 2) / 7);
			pDst[4].a = static_cast<uint8_t>((l * 4 + h * 3) / 7);
			pDst[5].a = static_cast<uint8_t>((l * 3 + h * 4) / 7);
			pDst[6].a = static_cast<uint8_t>((l * 2 + h * 5) / 7);
			pDst[7].a = static_cast<uint8_t>((l + h * 6) / 7);
			return 8;
		}

		static uint32_t get_block_values(color32* pDst, uint32_t l, uint32_t h)
		{
			if (l > h)
				return get_block_values8(pDst, l, h);
			else
				return get_block_values6(pDst, l, h);
		}
	};

	static void convert_etc1s_to_dxt5a(dxt5a_block* pDst_block, const endpoint* pEndpoints, const selector* pSelector)
	{
		const uint32_t low_selector = pSelector->m_lo_selector;
		const uint32_t high_selector = pSelector->m_hi_selector;

		const color32& base_color = pEndpoints->m_color5;
		const uint32_t inten_table = pEndpoints->m_inten5;

		if (low_selector == high_selector)
		{
			uint32_t r;
			decoder_etc_block::get_block_color5_r(base_color, inten_table, low_selector, r);
						
			pDst_block->set_low_alpha(r);
			pDst_block->set_high_alpha(r);
			pDst_block->m_selectors[0] = 0;
			pDst_block->m_selectors[1] = 0;
			pDst_block->m_selectors[2] = 0;
			pDst_block->m_selectors[3] = 0;
			pDst_block->m_selectors[4] = 0;
			pDst_block->m_selectors[5] = 0;
			return;
		}
		else if (pSelector->m_num_unique_selectors == 2)
		{
			color32 block_colors[4];

			decoder_etc_block::get_block_colors5(block_colors, base_color, inten_table);

			const uint32_t r0 = block_colors[low_selector].r;
			const uint32_t r1 = block_colors[high_selector].r;

			pDst_block->set_low_alpha(r0);
			pDst_block->set_high_alpha(r1);

			// TODO: Optimize this
			for (uint32_t y = 0; y < 4; y++)
			{
				for (uint32_t x = 0; x < 4; x++)
				{
					uint32_t s = pSelector->get_selector(x, y);
					pDst_block->set_selector(x, y, (s == high_selector) ? 1 : 0);
				}
			}

			return;
		}

		uint32_t selector_range_table = 0;
		for (selector_range_table = 0; selector_range_table < NUM_DXT5A_SELECTOR_RANGES; selector_range_table++)
			if ((low_selector == s_dxt5a_selector_ranges[selector_range_table].m_low) && (high_selector == s_dxt5a_selector_ranges[selector_range_table].m_high))
				break;
		if (selector_range_table >= NUM_DXT5A_SELECTOR_RANGES)
			selector_range_table = 0;

		const etc1_g_to_dxt5a_conversion* pTable_entry = &g_etc1_g_to_dxt5a[base_color.r + inten_table * 32][selector_range_table];

		pDst_block->set_low_alpha(pTable_entry->m_lo);
		pDst_block->set_high_alpha(pTable_entry->m_hi);

		// TODO: Optimize this (like ETC1->BC1)
		for (uint32_t y = 0; y < 4; y++)
		{
			for (uint32_t x = 0; x < 4; x++)
			{
				uint32_t s = pSelector->get_selector(x, y);

				uint32_t ds = (pTable_entry->m_trans >> (s * 3)) & 7;

				pDst_block->set_selector(x, y, ds);
			}
		}
	}
#endif //BASISD_SUPPORT_DXT5A

	// PVRTC

#if BASISD_SUPPORT_PVRTC1 || BASISD_SUPPORT_UASTC
	static const  uint16_t g_pvrtc_swizzle_table[256] =
	{
		0x0000, 0x0001, 0x0004, 0x0005, 0x0010, 0x0011, 0x0014, 0x0015, 0x0040, 0x0041, 0x0044, 0x0045, 0x0050, 0x0051, 0x0054, 0x0055, 0x0100, 0x0101, 0x0104, 0x0105, 0x0110, 0x0111, 0x0114, 0x0115, 0x0140, 0x0141, 0x0144, 0x0145, 0x0150, 0x0151, 0x0154, 0x0155,
		0x0400, 0x0401, 0x0404, 0x0405, 0x0410, 0x0411, 0x0414, 0x0415, 0x0440, 0x0441, 0x0444, 0x0445, 0x0450, 0x0451, 0x0454, 0x0455, 0x0500, 0x0501, 0x0504, 0x0505, 0x0510, 0x0511, 0x0514, 0x0515, 0x0540, 0x0541, 0x0544, 0x0545, 0x0550, 0x0551, 0x0554, 0x0555,
		0x1000, 0x1001, 0x1004, 0x1005, 0x1010, 0x1011, 0x1014, 0x1015, 0x1040, 0x1041, 0x1044, 0x1045, 0x1050, 0x1051, 0x1054, 0x1055, 0x1100, 0x1101, 0x1104, 0x1105, 0x1110, 0x1111, 0x1114, 0x1115, 0x1140, 0x1141, 0x1144, 0x1145, 0x1150, 0x1151, 0x1154, 0x1155,
		0x1400, 0x1401, 0x1404, 0x1405, 0x1410, 0x1411, 0x1414, 0x1415, 0x1440, 0x1441, 0x1444, 0x1445, 0x1450, 0x1451, 0x1454, 0x1455, 0x1500, 0x1501, 0x1504, 0x1505, 0x1510, 0x1511, 0x1514, 0x1515, 0x1540, 0x1541, 0x1544, 0x1545, 0x1550, 0x1551, 0x1554, 0x1555,
		0x4000, 0x4001, 0x4004, 0x4005, 0x4010, 0x4011, 0x4014, 0x4015, 0x4040, 0x4041, 0x4044, 0x4045, 0x4050, 0x4051, 0x4054, 0x4055, 0x4100, 0x4101, 0x4104, 0x4105, 0x4110, 0x4111, 0x4114, 0x4115, 0x4140, 0x4141, 0x4144, 0x4145, 0x4150, 0x4151, 0x4154, 0x4155,
		0x4400, 0x4401, 0x4404, 0x4405, 0x4410, 0x4411, 0x4414, 0x4415, 0x4440, 0x4441, 0x4444, 0x4445, 0x4450, 0x4451, 0x4454, 0x4455, 0x4500, 0x4501, 0x4504, 0x4505, 0x4510, 0x4511, 0x4514, 0x4515, 0x4540, 0x4541, 0x4544, 0x4545, 0x4550, 0x4551, 0x4554, 0x4555,
		0x5000, 0x5001, 0x5004, 0x5005, 0x5010, 0x5011, 0x5014, 0x5015, 0x5040, 0x5041, 0x5044, 0x5045, 0x5050, 0x5051, 0x5054, 0x5055, 0x5100, 0x5101, 0x5104, 0x5105, 0x5110, 0x5111, 0x5114, 0x5115, 0x5140, 0x5141, 0x5144, 0x5145, 0x5150, 0x5151, 0x5154, 0x5155,
		0x5400, 0x5401, 0x5404, 0x5405, 0x5410, 0x5411, 0x5414, 0x5415, 0x5440, 0x5441, 0x5444, 0x5445, 0x5450, 0x5451, 0x5454, 0x5455, 0x5500, 0x5501, 0x5504, 0x5505, 0x5510, 0x5511, 0x5514, 0x5515, 0x5540, 0x5541, 0x5544, 0x5545, 0x5550, 0x5551, 0x5554, 0x5555
	};

	// Note we can't use simple calculations to convert PVRTC1 encoded endpoint components to/from 8-bits, due to hardware approximations.
	static const uint8_t g_pvrtc_5[32] = { 0,8,16,24,33,41,49,57,66,74,82,90,99,107,115,123,132,140,148,156,165,173,181,189,198,206,214,222,231,239,247,255 };
	static const uint8_t g_pvrtc_4[16] = { 0,16,33,49,66,82,99,115,140,156,173,189,206,222,239,255 };
	static const uint8_t g_pvrtc_3[8] = { 0,33,74,107,148,181,222,255 };
	static const uint8_t g_pvrtc_alpha[9] = { 0,34,68,102,136,170,204,238,255 };
		
	static const uint8_t g_pvrtc_5_floor[256] =
	{
		0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,
		3,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,6,7,7,7,7,7,7,7,
		7,7,8,8,8,8,8,8,8,8,9,9,9,9,9,9,9,9,10,10,10,10,10,10,10,10,11,11,11,11,11,11,
		11,11,11,12,12,12,12,12,12,12,12,13,13,13,13,13,13,13,13,14,14,14,14,14,14,14,14,15,15,15,15,15,
		15,15,15,15,16,16,16,16,16,16,16,16,17,17,17,17,17,17,17,17,18,18,18,18,18,18,18,18,19,19,19,19,
		19,19,19,19,19,20,20,20,20,20,20,20,20,21,21,21,21,21,21,21,21,22,22,22,22,22,22,22,22,23,23,23,
		23,23,23,23,23,23,24,24,24,24,24,24,24,24,25,25,25,25,25,25,25,25,26,26,26,26,26,26,26,26,27,27,
		27,27,27,27,27,27,27,28,28,28,28,28,28,28,28,29,29,29,29,29,29,29,29,30,30,30,30,30,30,30,30,31
	};

	static const uint8_t g_pvrtc_5_ceil[256] =
	{
		0,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,
		4,4,5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,6,7,7,7,7,7,7,7,7,8,8,8,8,8,8,
		8,8,8,9,9,9,9,9,9,9,9,10,10,10,10,10,10,10,10,11,11,11,11,11,11,11,11,12,12,12,12,12,
		12,12,12,12,13,13,13,13,13,13,13,13,14,14,14,14,14,14,14,14,15,15,15,15,15,15,15,15,16,16,16,16,
		16,16,16,16,16,17,17,17,17,17,17,17,17,18,18,18,18,18,18,18,18,19,19,19,19,19,19,19,19,20,20,20,
		20,20,20,20,20,20,21,21,21,21,21,21,21,21,22,22,22,22,22,22,22,22,23,23,23,23,23,23,23,23,24,24,
		24,24,24,24,24,24,24,25,25,25,25,25,25,25,25,26,26,26,26,26,26,26,26,27,27,27,27,27,27,27,27,28,
		28,28,28,28,28,28,28,28,29,29,29,29,29,29,29,29,30,30,30,30,30,30,30,30,31,31,31,31,31,31,31,31
	};
		
	static const uint8_t g_pvrtc_4_floor[256] =
	{
		0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
		1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
		3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
		5,5,5,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,7,7,7,7,7,7,7,7,7,7,7,7,7,
		7,7,7,7,7,7,7,7,7,7,7,7,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,9,9,9,9,
		9,9,9,9,9,9,9,9,9,9,9,9,9,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,11,11,11,
		11,11,11,11,11,11,11,11,11,11,11,11,11,11,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,13,13,
		13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,15
	};

	static const uint8_t g_pvrtc_4_ceil[256] =
	{
		0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
		2,2,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
		4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,6,6,6,6,6,6,
		6,6,6,6,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,8,8,8,8,8,8,8,8,8,8,8,8,
		8,8,8,8,8,8,8,8,8,8,8,8,8,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,10,10,10,
		10,10,10,10,10,10,10,10,10,10,10,10,10,10,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,12,12,
		12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,14,
		14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15
	};
		
	static const uint8_t g_pvrtc_3_floor[256] =
	{
		0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
		0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
		1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
		2,2,2,2,2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
		3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,
		4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,
		5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,6,6,
		6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,7
	};

	static const uint8_t g_pvrtc_3_ceil[256] =
	{
		0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
		1,1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
		2,2,2,2,2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
		3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
		4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,
		5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,6,6,6,
		6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,7,
		7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
	};
		
	static const uint8_t g_pvrtc_alpha_floor[256] =
	{
		0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
		0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
		1,1,1,1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
		2,2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
		3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
		4,4,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
		5,5,5,5,5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
		6,6,6,6,6,6,6,6,6,6,6,6,6,6,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,8
	};

	static const uint8_t g_pvrtc_alpha_ceil[256] =
	{
		0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
		1,1,1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
		2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
		3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
		4,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
		5,5,5,5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
		6,6,6,6,6,6,6,6,6,6,6,6,6,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
		7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8
	};

	struct pvrtc4_block
	{
		uint32_t m_modulation;
		uint32_t m_endpoints;

		pvrtc4_block() : m_modulation(0), m_endpoints(0) { }

		inline bool operator== (const pvrtc4_block& rhs) const
		{
			return (m_modulation == rhs.m_modulation) && (m_endpoints == rhs.m_endpoints);
		}

		inline void clear()
		{
			m_modulation = 0;
			m_endpoints = 0;
		}

		inline bool get_block_uses_transparent_modulation() const
		{
			return (m_endpoints & 1) != 0;
		}

		inline void set_block_uses_transparent_modulation(bool m)
		{
			m_endpoints = (m_endpoints & ~1U) | static_cast<uint32_t>(m);
		}

		inline bool is_endpoint_opaque(uint32_t endpoint_index) const
		{
			static const uint32_t s_bitmasks[2] = { 0x8000U, 0x80000000U };
			return (m_endpoints & s_bitmasks[basisu::open_range_check(endpoint_index, 2U)]) != 0;
		}

		inline void set_endpoint_opaque(uint32_t endpoint_index, bool opaque)
		{
			assert(endpoint_index < 2);
			static const uint32_t s_bitmasks[2] = { 0x8000U, 0x80000000U };
			if (opaque)
				m_endpoints |= s_bitmasks[endpoint_index];
			else
				m_endpoints &= ~s_bitmasks[endpoint_index];
		}

		inline color32 get_endpoint_5554(uint32_t endpoint_index) const
		{
			assert(endpoint_index < 2);
			static const uint32_t s_endpoint_mask[2] = { 0xFFFE, 0xFFFF };
			uint32_t packed = (m_endpoints >> (basisu::open_range_check(endpoint_index, 2U) ? 16 : 0)) & s_endpoint_mask[endpoint_index];

			uint32_t r, g, b, a;
			if (packed & 0x8000)
			{
				// opaque 554 or 555
				r = (packed >> 10) & 31;
				g = (packed >> 5) & 31;
				b = packed & 31;

				if (!endpoint_index)
					b |= (b >> 4);

				a = 0xF;
			}
			else
			{
				// translucent 4433 or 4443
				r = (packed >> 7) & 0x1E;
				g = (packed >> 3) & 0x1E;
				b = (packed & 0xF) << 1;

				r |= (r >> 4);
				g |= (g >> 4);

				if (!endpoint_index)
					b |= (b >> 3);
				else
					b |= (b >> 4);

				a = (packed >> 11) & 0xE;
			}

			assert((r < 32) && (g < 32) && (b < 32) && (a < 16));
					
			return color32(r, g, b, a);
		}
				
		inline color32 get_endpoint_8888(uint32_t endpoint_index) const
		{
			assert(endpoint_index < 2);
			static const uint32_t s_endpoint_mask[2] = { 0xFFFE, 0xFFFF };
			uint32_t packed = (m_endpoints >> (basisu::open_range_check(endpoint_index, 2U) ? 16 : 0)) & s_endpoint_mask[endpoint_index];

			uint32_t r, g, b, a;
			if (packed & 0x8000)
			{
				// opaque 554 or 555
				// 1RRRRRGGGGGBBBBM
				// 1RRRRRGGGGGBBBBB
				r = (packed >> 10) & 31;
				g = (packed >> 5) & 31;
				b = packed & 31;

				r = g_pvrtc_5[r];
				g = g_pvrtc_5[g];

				if (!endpoint_index)
					b = g_pvrtc_4[b >> 1];
				else
					b = g_pvrtc_5[b];

				a = 255;
			}
			else
			{
				// translucent 4433 or 4443
				// 0AAA RRRR GGGG BBBM
				// 0AAA RRRR GGGG BBBB
				r = (packed >> 8) & 0xF;
				g = (packed >> 4) & 0xF;
				b = packed & 0xF;
				a = (packed >> 12) & 7;

				r = g_pvrtc_4[r];
				g = g_pvrtc_4[g];

				if (!endpoint_index)
					b = g_pvrtc_3[b >> 1];
				else
					b = g_pvrtc_4[b];

				a = g_pvrtc_alpha[a];
			}
			
			return color32(r, g, b, a);
		}

		inline uint32_t get_endpoint_l8(uint32_t endpoint_index) const
		{
			color32 c(get_endpoint_8888(endpoint_index));
			return c.r + c.g + c.b + c.a;
		}
				
		inline uint32_t get_opaque_endpoint_l0() const
		{
			uint32_t packed = m_endpoints & 0xFFFE;

			uint32_t r, g, b;
			assert(packed & 0x8000);

			// opaque 554 or 555
			r = (packed >> 10) & 31;
			g = (packed >> 5) & 31;
			b = packed & 31;
			b |= (b >> 4);

			return r + g + b;
		}

		inline uint32_t get_opaque_endpoint_l1() const
		{
			uint32_t packed = m_endpoints >> 16;

			uint32_t r, g, b;
			assert(packed & 0x8000);

			// opaque 554 or 555
			r = (packed >> 10) & 31;
			g = (packed >> 5) & 31;
			b = packed & 31;

			return r + g + b;
		}

		static uint32_t get_component_precision_in_bits(uint32_t c, uint32_t endpoint_index, bool opaque_endpoint)
		{
			static const uint32_t s_comp_prec[4][4] =
			{
				// R0 G0 B0 A0      R1 G1 B1 A1
				{ 4, 4, 3, 3 },{ 4, 4, 4, 3 }, // transparent endpoint

				{ 5, 5, 4, 0 },{ 5, 5, 5, 0 }  // opaque endpoint
			};
			return s_comp_prec[basisu::open_range_check(endpoint_index, 2U) + (opaque_endpoint * 2)][basisu::open_range_check(c, 4U)];
		}

		static color32 get_color_precision_in_bits(uint32_t endpoint_index, bool opaque_endpoint)
		{
			static const color32 s_color_prec[4] =
			{
				color32(4, 4, 3, 3), color32(4, 4, 4, 3), // transparent endpoint
				color32(5, 5, 4, 0), color32(5, 5, 5, 0)  // opaque endpoint
			};
			return s_color_prec[basisu::open_range_check(endpoint_index, 2U) + (opaque_endpoint * 2)];
		}

		inline void set_opaque_endpoint_floor(uint32_t endpoint_index, const color32& c)
		{
			assert(endpoint_index < 2);
			const uint32_t m = m_endpoints & 1;

			uint32_t r = g_pvrtc_5_floor[c[0]], g = g_pvrtc_5_floor[c[1]], b = c[2];

			if (!endpoint_index)
				b = g_pvrtc_4_floor[b] << 1;
			else
				b = g_pvrtc_5_floor[b];

			// rgba=555 here
			assert((r < 32) && (g < 32) && (b < 32));

			// 1RRRRRGGGGGBBBBM
			// 1RRRRRGGGGGBBBBB

			// opaque 554 or 555
			uint32_t packed = 0x8000 | (r << 10) | (g << 5) | b;
			if (!endpoint_index)
				packed = (packed & ~1) | m;

			assert(packed <= 0xFFFF);

			if (endpoint_index)
				m_endpoints = (m_endpoints & 0xFFFFU) | (packed << 16);
			else
				m_endpoints = (m_endpoints & 0xFFFF0000U) | packed;
		}

		inline void set_opaque_endpoint_ceil(uint32_t endpoint_index, const color32& c)
		{
			assert(endpoint_index < 2);
			const uint32_t m = m_endpoints & 1;

			uint32_t r = g_pvrtc_5_ceil[c[0]], g = g_pvrtc_5_ceil[c[1]], b = c[2];

			if (!endpoint_index)
				b = g_pvrtc_4_ceil[b] << 1;
			else
				b = g_pvrtc_5_ceil[b];

			// rgba=555 here
			assert((r < 32) && (g < 32) && (b < 32));

			// 1RRRRRGGGGGBBBBM
			// 1RRRRRGGGGGBBBBB

			// opaque 554 or 555
			uint32_t packed = 0x8000 | (r << 10) | (g << 5) | b;
			if (!endpoint_index)
				packed |= m;

			assert(packed <= 0xFFFF);

			if (endpoint_index)
				m_endpoints = (m_endpoints & 0xFFFFU) | (packed << 16);
			else
				m_endpoints = (m_endpoints & 0xFFFF0000U) | packed;
		}
				
		// opaque endpoints:	554 or 555
		// transparent endpoints: 3443 or 3444
		inline void set_endpoint_raw(uint32_t endpoint_index, const color32& c, bool opaque_endpoint)
		{
			assert(endpoint_index < 2);
			const uint32_t m = m_endpoints & 1;
			uint32_t r = c[0], g = c[1], b = c[2], a = c[3];

			uint32_t packed;

			if (opaque_endpoint)
			{
				if (!endpoint_index)
				{
					// 554
					// 1RRRRRGGGGGBBBBM
					assert((r < 32) && (g < 32) && (b < 16));
					packed = 0x8000 | (r << 10) | (g << 5) | (b << 1) | m;
				}
				else
				{
					// 555
					// 1RRRRRGGGGGBBBBB
					assert((r < 32) && (g < 32) && (b < 32));
					packed = 0x8000 | (r << 10) | (g << 5) | b;
				}
			}
			else
			{
				if (!endpoint_index)
				{
					// 3443
					// 0AAA RRRR GGGG BBBM
					assert((r < 16) && (g < 16) && (b < 8) && (a < 8));
					packed = (a << 12) | (r << 8) | (g << 4) | (b << 1) | m;
				}
				else
				{
					// 3444
					// 0AAA RRRR GGGG BBBB
					assert((r < 16) && (g < 16) && (b < 16) && (a < 8));
					packed = (a << 12) | (r << 8) | (g << 4) | b;
				}
			}

			assert(packed <= 0xFFFF);

			if (endpoint_index)
				m_endpoints = (m_endpoints & 0xFFFFU) | (packed << 16);
			else
				m_endpoints = (m_endpoints & 0xFFFF0000U) | packed;
		}
				
		inline void set_endpoint_floor(uint32_t endpoint_index, const color32& c)
		{
			assert(endpoint_index < 2);

			int a = g_pvrtc_alpha_floor[c.a];
			if (a == 8)
			{
				// 554 or 555
				uint32_t r = g_pvrtc_5_floor[c[0]], g = g_pvrtc_5_floor[c[1]], b = c[2];

				if (!endpoint_index)
					b = g_pvrtc_4_floor[b];
				else
					b = g_pvrtc_5_floor[b];

				set_endpoint_raw(endpoint_index, color32(r, g, b, a), true);
			}
			else
			{
				// 4433 or 4443
				uint32_t r = g_pvrtc_4_floor[c[0]], g = g_pvrtc_4_floor[c[1]], b = c[2];

				if (!endpoint_index)
					b = g_pvrtc_3_floor[b];
				else
					b = g_pvrtc_4_floor[b];

				set_endpoint_raw(endpoint_index, color32(r, g, b, a), false);
			}
		}

		inline void set_endpoint_ceil(uint32_t endpoint_index, const color32& c)
		{
			assert(endpoint_index < 2);

			int a = g_pvrtc_alpha_ceil[c.a];
			if (a == 8)
			{
				// 554 or 555
				uint32_t r = g_pvrtc_5_ceil[c[0]], g = g_pvrtc_5_ceil[c[1]], b = c[2];

				if (!endpoint_index)
					b = g_pvrtc_4_ceil[b];
				else
					b = g_pvrtc_5_ceil[b];

				set_endpoint_raw(endpoint_index, color32(r, g, b, a), true);
			}
			else
			{
				// 4433 or 4443
				uint32_t r = g_pvrtc_4_ceil[c[0]], g = g_pvrtc_4_ceil[c[1]], b = c[2];

				if (!endpoint_index)
					b = g_pvrtc_3_ceil[b];
				else
					b = g_pvrtc_4_ceil[b];

				set_endpoint_raw(endpoint_index, color32(r, g, b, a), false);
			}
		}

		inline uint32_t get_modulation(uint32_t x, uint32_t y) const
		{
			assert((x < 4) && (y < 4));
			return (m_modulation >> ((y * 4 + x) * 2)) & 3;
		}

		// Scaled by 8
		inline const uint32_t* get_scaled_modulation_values(bool block_uses_transparent_modulation) const
		{
			static const uint32_t s_block_scales[2][4] = { { 0, 3, 5, 8 },{ 0, 4, 4, 8 } };
			return s_block_scales[block_uses_transparent_modulation];
		}

		// Scaled by 8
		inline uint32_t get_scaled_modulation(uint32_t x, uint32_t y) const
		{
			return get_scaled_modulation_values(get_block_uses_transparent_modulation())[get_modulation(x, y)];
		}

		inline void set_modulation(uint32_t x, uint32_t y, uint32_t s)
		{
			assert((x < 4) && (y < 4) && (s < 4));
			uint32_t n = (y * 4 + x) * 2;
			m_modulation = (m_modulation & (~(3 << n))) | (s << n);
			assert(get_modulation(x, y) == s);
		}

		// Assumes modulation was initialized to 0
		inline void set_modulation_fast(uint32_t x, uint32_t y, uint32_t s)
		{
			assert((x < 4) && (y < 4) && (s < 4));
			uint32_t n = (y * 4 + x) * 2;
			m_modulation |= (s << n);
			assert(get_modulation(x, y) == s);
		}
	};

#if 0
	static const uint8_t g_pvrtc_bilinear_weights[16][4] =
	{
		{ 4, 4, 4, 4 }, { 2, 6, 2, 6 }, { 8, 0, 8, 0 }, { 6, 2, 6, 2 },
		{ 2, 2, 6, 6 }, { 1, 3, 3, 9 }, { 4, 0, 12, 0 }, { 3, 1, 9, 3 },
		{ 8, 8, 0, 0 }, { 4, 12, 0, 0 }, { 16, 0, 0, 0 }, { 12, 4, 0, 0 },
		{ 6, 6, 2, 2 }, { 3, 9, 1, 3 }, { 12, 0, 4, 0 }, { 9, 3, 3, 1 },
	};
#endif

	struct pvrtc1_temp_block
	{
		decoder_etc_block m_etc1_block;
		uint32_t m_pvrtc_endpoints;
	};

	static inline uint32_t get_opaque_endpoint_l0(uint32_t endpoints)
	{
		uint32_t packed = endpoints;

		uint32_t r, g, b;
		assert(packed & 0x8000);

		r = (packed >> 10) & 31;
		g = (packed >> 5) & 31;
		b = packed & 30;
		b |= (b >> 4);

		return r + g + b;
	}

	static inline uint32_t get_opaque_endpoint_l1(uint32_t endpoints)
	{
		uint32_t packed = endpoints >> 16;

		uint32_t r, g, b;
		assert(packed & 0x8000);

		r = (packed >> 10) & 31;
		g = (packed >> 5) & 31;
		b = packed & 31;

		return r + g + b;
	}

	static color32 get_endpoint_8888(uint32_t endpoints, uint32_t endpoint_index)
	{
		assert(endpoint_index < 2);
		static const uint32_t s_endpoint_mask[2] = { 0xFFFE, 0xFFFF };
		uint32_t packed = (endpoints >> (basisu::open_range_check(endpoint_index, 2U) ? 16 : 0)) & s_endpoint_mask[endpoint_index];

		uint32_t r, g, b, a;
		if (packed & 0x8000)
		{
			// opaque 554 or 555
			// 1RRRRRGGGGGBBBBM
			// 1RRRRRGGGGGBBBBB
			r = (packed >> 10) & 31;
			g = (packed >> 5) & 31;
			b = packed & 31;

			r = g_pvrtc_5[r];
			g = g_pvrtc_5[g];

			if (!endpoint_index)
				b = g_pvrtc_4[b >> 1];
			else
				b = g_pvrtc_5[b];

			a = 255;
		}
		else
		{
			// translucent 4433 or 4443
			// 0AAA RRRR GGGG BBBM
			// 0AAA RRRR GGGG BBBB
			r = (packed >> 8) & 0xF;
			g = (packed >> 4) & 0xF;
			b = packed & 0xF;
			a = (packed >> 12) & 7;

			r = g_pvrtc_4[r];
			g = g_pvrtc_4[g];

			if (!endpoint_index)
				b = g_pvrtc_3[b >> 1];
			else
				b = g_pvrtc_4[b];

			a = g_pvrtc_alpha[a];
		}

		return color32(r, g, b, a);
	}

	static uint32_t get_endpoint_l8(uint32_t endpoints, uint32_t endpoint_index)
	{
		color32 c(get_endpoint_8888(endpoints, endpoint_index));
		return c.r + c.g + c.b + c.a;
	}
#endif

#if BASISD_SUPPORT_PVRTC1
	// TODO: Support decoding a non-pow2 ETC1S texture into the next larger pow2 PVRTC texture.
	static void fixup_pvrtc1_4_modulation_rgb(const decoder_etc_block* pETC_Blocks, const uint32_t* pPVRTC_endpoints, void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y)
	{
		const uint32_t x_mask = num_blocks_x - 1;
		const uint32_t y_mask = num_blocks_y - 1;
		const uint32_t x_bits = basisu::total_bits(x_mask);
		const uint32_t y_bits = basisu::total_bits(y_mask);
		const uint32_t min_bits = basisu::minimum(x_bits, y_bits);
		//const uint32_t max_bits = basisu::maximum(x_bits, y_bits);
		const uint32_t swizzle_mask = (1 << (min_bits * 2)) - 1;

		uint32_t block_index = 0;

		// really 3x3
		int e0[4][4], e1[4][4];

		for (int y = 0; y < static_cast<int>(num_blocks_y); y++)
		{
			const uint32_t* pE_rows[3];

			for (int ey = 0; ey < 3; ey++)
			{
				int by = y + ey - 1; 

				const uint32_t* pE = &pPVRTC_endpoints[(by & y_mask) * num_blocks_x];

				pE_rows[ey] = pE;

				for (int ex = 0; ex < 3; ex++)
				{
					int bx = 0 + ex - 1; 

					const uint32_t e = pE[bx & x_mask];

					e0[ex][ey] = (get_opaque_endpoint_l0(e) * 255) / 31;
					e1[ex][ey] = (get_opaque_endpoint_l1(e) * 255) / 31;
				}
			}

			const uint32_t y_swizzle = (g_pvrtc_swizzle_table[y >> 8] << 16) | g_pvrtc_swizzle_table[y & 0xFF];

			for (int x = 0; x < static_cast<int>(num_blocks_x); x++, block_index++)
			{
				const decoder_etc_block& src_block = pETC_Blocks[block_index];

				const uint32_t x_swizzle = (g_pvrtc_swizzle_table[x >> 8] << 17) | (g_pvrtc_swizzle_table[x & 0xFF] << 1);

				uint32_t swizzled = x_swizzle | y_swizzle;
				if (num_blocks_x != num_blocks_y)
				{
					swizzled &= swizzle_mask;

					if (num_blocks_x > num_blocks_y)
						swizzled |= ((x >> min_bits) << (min_bits * 2));
					else
						swizzled |= ((y >> min_bits) << (min_bits * 2));
				}

				pvrtc4_block* pDst_block = static_cast<pvrtc4_block*>(pDst_blocks) + swizzled;
				pDst_block->m_endpoints = pPVRTC_endpoints[block_index];

				uint32_t base_r = g_etc_5_to_8[src_block.m_differential.m_red1];
				uint32_t base_g = g_etc_5_to_8[src_block.m_differential.m_green1];
				uint32_t base_b = g_etc_5_to_8[src_block.m_differential.m_blue1];

				const int* pInten_table48 = g_etc1_inten_tables48[src_block.m_differential.m_cw1];
				int by = (base_r + base_g + base_b) * 16;
				int block_colors_y_x16[4];
				block_colors_y_x16[0] = by + pInten_table48[2];
				block_colors_y_x16[1] = by + pInten_table48[3];
				block_colors_y_x16[2] = by + pInten_table48[1];
				block_colors_y_x16[3] = by + pInten_table48[0];

				{
					const uint32_t ex = 2;
					int bx = x + ex - 1;
					bx &= x_mask;

#define DO_ROW(ey) \
					{ \
						const uint32_t e = pE_rows[ey][bx]; \
						e0[ex][ey] = (get_opaque_endpoint_l0(e) * 255) / 31; \
						e1[ex][ey] = (get_opaque_endpoint_l1(e) * 255) / 31; \
					}

					DO_ROW(0);
					DO_ROW(1);
					DO_ROW(2);
#undef DO_ROW
				}

				uint32_t mod = 0;

				uint32_t lookup_x[4];

#define DO_LOOKUP(lx) { \
					const uint32_t byte_ofs = 7 - (((lx) * 4) >> 3); \
					const uint32_t lsb_bits = src_block.m_bytes[byte_ofs] >> (((lx) & 1) * 4); \
					const uint32_t msb_bits = src_block.m_bytes[byte_ofs - 2] >> (((lx) & 1) * 4); \
					lookup_x[lx] = (lsb_bits & 0xF) | ((msb_bits & 0xF) << 4); }

				DO_LOOKUP(0);
				DO_LOOKUP(1);
				DO_LOOKUP(2);
				DO_LOOKUP(3);
#undef DO_LOOKUP

#define DO_PIX(lx, ly, w0, w1, w2, w3) \
				{ \
					int ca_l = a0 * w0 + a1 * w1 + a2 * w2 + a3 * w3; \
					int cb_l = b0 * w0 + b1 * w1 + b2 * w2 + b3 * w3; \
					int cl = block_colors_y_x16[g_etc1_x_selector_unpack[ly][lookup_x[lx]]]; \
					int dl = cb_l - ca_l; \
					int vl = cl - ca_l; \
					int p = vl * 16; \
					if (ca_l > cb_l) { p = -p; dl = -dl; } \
					uint32_t m = 0; \
					if (p > 3 * dl) m = (uint32_t)(1 << ((ly) * 8 + (lx) * 2)); \
					if (p > 8 * dl) m = (uint32_t)(2 << ((ly) * 8 + (lx) * 2)); \
					if (p > 13 * dl) m = (uint32_t)(3 << ((ly) * 8 + (lx) * 2)); \
					mod |= m; \
				}

				{
					const uint32_t ex = 0, ey = 0;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(0, 0, 4, 4, 4, 4);
					DO_PIX(1, 0, 2, 6, 2, 6);
					DO_PIX(0, 1, 2, 2, 6, 6);
					DO_PIX(1, 1, 1, 3, 3, 9);
				}

				{
					const uint32_t ex = 1, ey = 0;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(2, 0, 8, 0, 8, 0);
					DO_PIX(3, 0, 6, 2, 6, 2);
					DO_PIX(2, 1, 4, 0, 12, 0);
					DO_PIX(3, 1, 3, 1, 9, 3);
				}

				{
					const uint32_t ex = 0, ey = 1;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(0, 2, 8, 8, 0, 0);
					DO_PIX(1, 2, 4, 12, 0, 0);
					DO_PIX(0, 3, 6, 6, 2, 2);
					DO_PIX(1, 3, 3, 9, 1, 3);
				}

				{
					const uint32_t ex = 1, ey = 1;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(2, 2, 16, 0, 0, 0);
					DO_PIX(3, 2, 12, 4, 0, 0);
					DO_PIX(2, 3, 12, 0, 4, 0);
					DO_PIX(3, 3, 9, 3, 3, 1);
				}
#undef DO_PIX

				pDst_block->m_modulation = mod;

				e0[0][0] = e0[1][0]; e0[1][0] = e0[2][0];
				e0[0][1] = e0[1][1]; e0[1][1] = e0[2][1];
				e0[0][2] = e0[1][2]; e0[1][2] = e0[2][2];

				e1[0][0] = e1[1][0]; e1[1][0] = e1[2][0];
				e1[0][1] = e1[1][1]; e1[1][1] = e1[2][1];
				e1[0][2] = e1[1][2]; e1[1][2] = e1[2][2];

			} // x
		} // y
	}

	static void fixup_pvrtc1_4_modulation_rgba(
		const decoder_etc_block* pETC_Blocks, 
		const uint32_t* pPVRTC_endpoints, 
		void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y, void *pAlpha_blocks,
		const endpoint* pEndpoints, const selector* pSelectors)
	{
		const uint32_t x_mask = num_blocks_x - 1;
		const uint32_t y_mask = num_blocks_y - 1;
		const uint32_t x_bits = basisu::total_bits(x_mask);
		const uint32_t y_bits = basisu::total_bits(y_mask);
		const uint32_t min_bits = basisu::minimum(x_bits, y_bits);
		//const uint32_t max_bits = basisu::maximum(x_bits, y_bits);
		const uint32_t swizzle_mask = (1 << (min_bits * 2)) - 1;

		uint32_t block_index = 0;

		// really 3x3
		int e0[4][4], e1[4][4];

		for (int y = 0; y < static_cast<int>(num_blocks_y); y++)
		{
			const uint32_t* pE_rows[3];

			for (int ey = 0; ey < 3; ey++)
			{
				int by = y + ey - 1; 

				const uint32_t* pE = &pPVRTC_endpoints[(by & y_mask) * num_blocks_x];

				pE_rows[ey] = pE;

				for (int ex = 0; ex < 3; ex++)
				{
					int bx = 0 + ex - 1; 

					const uint32_t e = pE[bx & x_mask];

					e0[ex][ey] = get_endpoint_l8(e, 0);
					e1[ex][ey] = get_endpoint_l8(e, 1);
				}
			}

			const uint32_t y_swizzle = (g_pvrtc_swizzle_table[y >> 8] << 16) | g_pvrtc_swizzle_table[y & 0xFF];

			for (int x = 0; x < static_cast<int>(num_blocks_x); x++, block_index++)
			{
				const decoder_etc_block& src_block = pETC_Blocks[block_index];
				
				const uint16_t* pSrc_alpha_block = reinterpret_cast<const uint16_t*>(static_cast<const uint32_t*>(pAlpha_blocks) + x + (y * num_blocks_x));
				const endpoint* pAlpha_endpoints = &pEndpoints[pSrc_alpha_block[0]];
				const selector* pAlpha_selectors = &pSelectors[pSrc_alpha_block[1]];
				
				const uint32_t x_swizzle = (g_pvrtc_swizzle_table[x >> 8] << 17) | (g_pvrtc_swizzle_table[x & 0xFF] << 1);
				
				uint32_t swizzled = x_swizzle | y_swizzle;
				if (num_blocks_x != num_blocks_y)
				{
					swizzled &= swizzle_mask;

					if (num_blocks_x > num_blocks_y)
						swizzled |= ((x >> min_bits) << (min_bits * 2));
					else
						swizzled |= ((y >> min_bits) << (min_bits * 2));
				}

				pvrtc4_block* pDst_block = static_cast<pvrtc4_block*>(pDst_blocks) + swizzled;
				pDst_block->m_endpoints = pPVRTC_endpoints[block_index];

				uint32_t base_r = g_etc_5_to_8[src_block.m_differential.m_red1];
				uint32_t base_g = g_etc_5_to_8[src_block.m_differential.m_green1];
				uint32_t base_b = g_etc_5_to_8[src_block.m_differential.m_blue1];

				const int* pInten_table48 = g_etc1_inten_tables48[src_block.m_differential.m_cw1];
				int by = (base_r + base_g + base_b) * 16;
				int block_colors_y_x16[4];
				block_colors_y_x16[0] = basisu::clamp<int>(by + pInten_table48[0], 0, 48 * 255);
				block_colors_y_x16[1] = basisu::clamp<int>(by + pInten_table48[1], 0, 48 * 255);
				block_colors_y_x16[2] = basisu::clamp<int>(by + pInten_table48[2], 0, 48 * 255);
				block_colors_y_x16[3] = basisu::clamp<int>(by + pInten_table48[3], 0, 48 * 255);

				uint32_t alpha_base_g = g_etc_5_to_8[pAlpha_endpoints->m_color5.g] * 16;
				const int* pInten_table16 = g_etc1_inten_tables16[pAlpha_endpoints->m_inten5];
				int alpha_block_colors_x16[4];
				alpha_block_colors_x16[0] = basisu::clamp<int>(alpha_base_g + pInten_table16[0], 0, 16 * 255);
				alpha_block_colors_x16[1] = basisu::clamp<int>(alpha_base_g + pInten_table16[1], 0, 16 * 255);
				alpha_block_colors_x16[2] = basisu::clamp<int>(alpha_base_g + pInten_table16[2], 0, 16 * 255);
				alpha_block_colors_x16[3] = basisu::clamp<int>(alpha_base_g + pInten_table16[3], 0, 16 * 255);

				// clamp((base_r + base_g + base_b) * 16 + color_inten[s] * 48) + clamp(alpha_base_g * 16 + alpha_inten[as] * 16)

				{
					const uint32_t ex = 2;
					int bx = x + ex - 1;
					bx &= x_mask;

#define DO_ROW(ey) \
					{ \
						const uint32_t e = pE_rows[ey][bx]; \
						e0[ex][ey] = get_endpoint_l8(e, 0); \
						e1[ex][ey] = get_endpoint_l8(e, 1); \
					}

					DO_ROW(0);
					DO_ROW(1);
					DO_ROW(2);
#undef DO_ROW
				}

				uint32_t mod = 0;

#define DO_PIX(lx, ly, w0, w1, w2, w3) \
				{ \
					int ca_l = a0 * w0 + a1 * w1 + a2 * w2 + a3 * w3; \
					int cb_l = b0 * w0 + b1 * w1 + b2 * w2 + b3 * w3; \
					int cl = block_colors_y_x16[(src_block.m_bytes[4 + ly] >> (lx * 2)) & 3] + alpha_block_colors_x16[(pAlpha_selectors->m_selectors[ly] >> (lx * 2)) & 3]; \
					int dl = cb_l - ca_l; \
					int vl = cl - ca_l; \
					int p = vl * 16; \
					if (ca_l > cb_l) { p = -p; dl = -dl; } \
					uint32_t m = 0; \
					if (p > 3 * dl) m = (uint32_t)(1 << ((ly) * 8 + (lx) * 2)); \
					if (p > 8 * dl) m = (uint32_t)(2 << ((ly) * 8 + (lx) * 2)); \
					if (p > 13 * dl) m = (uint32_t)(3 << ((ly) * 8 + (lx) * 2)); \
					mod |= m; \
				}

				{
					const uint32_t ex = 0, ey = 0;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(0, 0, 4, 4, 4, 4);
					DO_PIX(1, 0, 2, 6, 2, 6);
					DO_PIX(0, 1, 2, 2, 6, 6);
					DO_PIX(1, 1, 1, 3, 3, 9);
				}

				{
					const uint32_t ex = 1, ey = 0;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(2, 0, 8, 0, 8, 0);
					DO_PIX(3, 0, 6, 2, 6, 2);
					DO_PIX(2, 1, 4, 0, 12, 0);
					DO_PIX(3, 1, 3, 1, 9, 3);
				}

				{
					const uint32_t ex = 0, ey = 1;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(0, 2, 8, 8, 0, 0);
					DO_PIX(1, 2, 4, 12, 0, 0);
					DO_PIX(0, 3, 6, 6, 2, 2);
					DO_PIX(1, 3, 3, 9, 1, 3);
				}

				{
					const uint32_t ex = 1, ey = 1;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(2, 2, 16, 0, 0, 0);
					DO_PIX(3, 2, 12, 4, 0, 0);
					DO_PIX(2, 3, 12, 0, 4, 0);
					DO_PIX(3, 3, 9, 3, 3, 1);
				}
#undef DO_PIX

				pDst_block->m_modulation = mod;

				e0[0][0] = e0[1][0]; e0[1][0] = e0[2][0];
				e0[0][1] = e0[1][1]; e0[1][1] = e0[2][1];
				e0[0][2] = e0[1][2]; e0[1][2] = e0[2][2];

				e1[0][0] = e1[1][0]; e1[1][0] = e1[2][0];
				e1[0][1] = e1[1][1]; e1[1][1] = e1[2][1];
				e1[0][2] = e1[1][2]; e1[1][2] = e1[2][2];

			} // x
		} // y
	}
#endif // BASISD_SUPPORT_PVRTC1

#if BASISD_SUPPORT_BC7_MODE5
	static dxt_selector_range g_etc1_to_bc7_m5_selector_ranges[] =
	{
		{ 0, 3 },
		{ 1, 3 },
		{ 0, 2 },
		{ 1, 2 },
		{ 2, 3 },
		{ 0, 1 },
	};

	const uint32_t NUM_ETC1_TO_BC7_M5_SELECTOR_RANGES = sizeof(g_etc1_to_bc7_m5_selector_ranges) / sizeof(g_etc1_to_bc7_m5_selector_ranges[0]);

	static uint32_t g_etc1_to_bc7_m5_selector_range_index[4][4];
	
	const uint32_t NUM_ETC1_TO_BC7_M5_SELECTOR_MAPPINGS = 10;
	static const uint8_t g_etc1_to_bc7_m5_selector_mappings[NUM_ETC1_TO_BC7_M5_SELECTOR_MAPPINGS][4] =
	{
		{ 0, 0, 1, 1 },
		{ 0, 0, 1, 2 },
		{ 0, 0, 1, 3 },
		{ 0, 0, 2, 3 },
		{ 0, 1, 1, 1 },
		{ 0, 1, 2, 2 },
		{ 0, 1, 2, 3 },
		{ 0, 2, 3, 3 },
		{ 1, 2, 2, 2 },
		{ 1, 2, 3, 3 },
	};

	struct etc1_to_bc7_m5_solution
	{
		uint8_t m_lo;
		uint8_t m_hi;
		uint16_t m_err;
	};
		
	static const etc1_to_bc7_m5_solution g_etc1_to_bc7_m5_color[32 * 8 * NUM_ETC1_TO_BC7_M5_SELECTOR_MAPPINGS * NUM_ETC1_TO_BC7_M5_SELECTOR_RANGES] = {
#include "basisu_transcoder_tables_bc7_m5_color.inc"
	};
	
	static dxt_selector_range g_etc1_to_bc7_m5a_selector_ranges[] =
	{
		{ 0, 3 },
		{ 1, 3 },
		{ 0, 2 },
		{ 1, 2 },
		{ 2, 3 },
		{ 0, 1 }
	};

	const uint32_t NUM_ETC1_TO_BC7_M5A_SELECTOR_RANGES = sizeof(g_etc1_to_bc7_m5a_selector_ranges) / sizeof(g_etc1_to_bc7_m5a_selector_ranges[0]);

	static uint32_t g_etc1_to_bc7_m5a_selector_range_index[4][4];

	struct etc1_g_to_bc7_m5a_conversion
	{
		uint8_t m_lo, m_hi;
		uint8_t m_trans;
	};

	static etc1_g_to_bc7_m5a_conversion g_etc1_g_to_bc7_m5a[8 * 32 * NUM_ETC1_TO_BC7_M5A_SELECTOR_RANGES] =
	{
		#include "basisu_transcoder_tables_bc7_m5_alpha.inc"
	};
	
	static inline uint32_t set_block_bits(uint8_t* pBytes, uint32_t val, uint32_t num_bits, uint32_t cur_ofs)
	{
		assert(num_bits < 32);
		assert(val < (1ULL << num_bits));

		uint32_t mask = static_cast<uint32_t>((1ULL << num_bits) - 1);

		while (num_bits)
		{
			const uint32_t n = basisu::minimum<uint32_t>(8 - (cur_ofs & 7), num_bits);

			pBytes[cur_ofs >> 3] &= ~static_cast<uint8_t>(mask << (cur_ofs & 7));
			pBytes[cur_ofs >> 3] |= static_cast<uint8_t>(val << (cur_ofs & 7));

			val >>= n;
			mask >>= n;

			num_bits -= n;
			cur_ofs += n;
		}

		return cur_ofs;
	}

	struct bc7_mode_5
	{
		union
		{
			struct
			{
				uint64_t m_mode : 6;
				uint64_t m_rot : 2;

				uint64_t m_r0 : 7;
				uint64_t m_r1 : 7;
				uint64_t m_g0 : 7;
				uint64_t m_g1 : 7;
				uint64_t m_b0 : 7;
				uint64_t m_b1 : 7;
				uint64_t m_a0 : 8;
				uint64_t m_a1_0 : 6;

			} m_lo;

			uint64_t m_lo_bits;
		};

		union
		{
			struct
			{
				uint64_t m_a1_1 : 2;

				// bit 2
				uint64_t m_c00 : 1;
				uint64_t m_c10 : 2;
				uint64_t m_c20 : 2;
				uint64_t m_c30 : 2;

				uint64_t m_c01 : 2;
				uint64_t m_c11 : 2;
				uint64_t m_c21 : 2;
				uint64_t m_c31 : 2;

				uint64_t m_c02 : 2;
				uint64_t m_c12 : 2;
				uint64_t m_c22 : 2;
				uint64_t m_c32 : 2;

				uint64_t m_c03 : 2;
				uint64_t m_c13 : 2;
				uint64_t m_c23 : 2;
				uint64_t m_c33 : 2;

				// bit 33
				uint64_t m_a00 : 1;
				uint64_t m_a10 : 2;
				uint64_t m_a20 : 2;
				uint64_t m_a30 : 2;

				uint64_t m_a01 : 2;
				uint64_t m_a11 : 2;
				uint64_t m_a21 : 2;
				uint64_t m_a31 : 2;

				uint64_t m_a02 : 2;
				uint64_t m_a12 : 2;
				uint64_t m_a22 : 2;
				uint64_t m_a32 : 2;

				uint64_t m_a03 : 2;
				uint64_t m_a13 : 2;
				uint64_t m_a23 : 2;
				uint64_t m_a33 : 2;

			} m_hi;

			uint64_t m_hi_bits;
		};
	};

#if BASISD_WRITE_NEW_BC7_MODE5_TABLES
	static void create_etc1_to_bc7_m5_color_conversion_table()
	{
		FILE* pFile = nullptr;
		fopen_s(&pFile, "basisu_transcoder_tables_bc7_m5_color.inc", "w");

		uint32_t n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1_TO_BC7_M5_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1_to_bc7_m5_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1_to_bc7_m5_selector_ranges[sr].m_high;

					for (uint32_t m = 0; m < NUM_ETC1_TO_BC7_M5_SELECTOR_MAPPINGS; m++)
					{
						uint32_t best_lo = 0;
						uint32_t best_hi = 0;
						uint64_t best_err = UINT64_MAX;

						for (uint32_t hi = 0; hi <= 127; hi++)
						{
							for (uint32_t lo = 0; lo <= 127; lo++)
							{
								uint32_t colors[4];

								colors[0] = (lo << 1) | (lo >> 6);
								colors[3] = (hi << 1) | (hi >> 6);

								colors[1] = (colors[0] * (64 - 21) + colors[3] * 21 + 32) / 64;
								colors[2] = (colors[0] * (64 - 43) + colors[3] * 43 + 32) / 64;

								uint64_t total_err = 0;

								for (uint32_t s = low_selector; s <= high_selector; s++)
								{
									int err = block_colors[s].g - colors[g_etc1_to_bc7_m5_selector_mappings[m][s]];

									int err_scale = 1;
									// Special case when the intensity table is 7, low_selector is 0, and high_selector is 3. In this extreme case, it's likely the encoder is trying to strongly favor 
									// the low/high selectors which are clamping to either 0 or 255.
									if (((inten == 7) && (low_selector == 0) && (high_selector == 3)) && ((s == 0) || (s == 3)))
										err_scale = 5;

									total_err += (err * err) * err_scale;
								}

								if (total_err < best_err)
								{
									best_err = total_err;
									best_lo = lo;
									best_hi = hi;
								}
							}
						}

						best_err = basisu::minimum<uint32_t>(best_err, 0xFFFF);

						fprintf(pFile, "{%u,%u,%u},", best_lo, best_hi, (uint32_t)best_err);
						n++;
						if ((n & 31) == 31)
							fprintf(pFile, "\n");
					} // m
				} // sr
			} // g
		} // inten

		fclose(pFile);
	}

	static void create_etc1_to_bc7_m5_alpha_conversion_table()
	{
		FILE* pFile = nullptr;
		fopen_s(&pFile, "basisu_transcoder_tables_bc7_m5_alpha.inc", "w");

		uint32_t n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1_TO_BC7_M5A_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1_to_bc7_m5a_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1_to_bc7_m5a_selector_ranges[sr].m_high;

					uint32_t best_lo = 0;
					uint32_t best_hi = 0;
					uint64_t best_err = UINT64_MAX;
					uint32_t best_output_selectors = 0;

					for (uint32_t hi = 0; hi <= 255; hi++)
					{
						for (uint32_t lo = 0; lo <= 255; lo++)
						{
							uint32_t colors[4];

							colors[0] = lo;
							colors[3] = hi;

							colors[1] = (colors[0] * (64 - 21) + colors[3] * 21 + 32) / 64;
							colors[2] = (colors[0] * (64 - 43) + colors[3] * 43 + 32) / 64;

							uint64_t total_err = 0;
							uint32_t output_selectors = 0;

							for (uint32_t s = low_selector; s <= high_selector; s++)
							{
								int best_mapping_err = INT_MAX;
								int best_k = 0;
								for (int k = 0; k < 4; k++)
								{
									int mapping_err = block_colors[s].g - colors[k];
									mapping_err *= mapping_err;

									// Special case when the intensity table is 7, low_selector is 0, and high_selector is 3. In this extreme case, it's likely the encoder is trying to strongly favor 
									// the low/high selectors which are clamping to either 0 or 255.
									if (((inten == 7) && (low_selector == 0) && (high_selector == 3)) && ((s == 0) || (s == 3)))
										mapping_err *= 5;

									if (mapping_err < best_mapping_err)
									{
										best_mapping_err = mapping_err;
										best_k = k;
									}
								} // k
								
								total_err += best_mapping_err;
								output_selectors |= (best_k << (s * 2));
							} // s

							if (total_err < best_err)
							{
								best_err = total_err;
								best_lo = lo;
								best_hi = hi;
								best_output_selectors = output_selectors;
							}

						} // lo
					} // hi
										
					fprintf(pFile, "{%u,%u,%u},", best_lo, best_hi, best_output_selectors);
					n++;
					if ((n & 31) == 31)
						fprintf(pFile, "\n");

				} // sr
			} // g
		} // inten

		fclose(pFile);
	}
#endif // BASISD_WRITE_NEW_BC7_MODE5_TABLES

	struct bc7_m5_match_entry
	{
		uint8_t m_hi;
		uint8_t m_lo;
	};

	static bc7_m5_match_entry g_bc7_m5_equals_1[256] =
	{
		{0,0},{1,0},{3,0},{4,0},{6,0},{7,0},{9,0},{10,0},{12,0},{13,0},{15,0},{16,0},{18,0},{20,0},{21,0},{23,0},
		{24,0},{26,0},{27,0},{29,0},{30,0},{32,0},{33,0},{35,0},{36,0},{38,0},{39,0},{41,0},{42,0},{44,0},{45,0},{47,0},
		{48,0},{50,0},{52,0},{53,0},{55,0},{56,0},{58,0},{59,0},{61,0},{62,0},{64,0},{65,0},{66,0},{68,0},{69,0},{71,0},
		{72,0},{74,0},{75,0},{77,0},{78,0},{80,0},{82,0},{83,0},{85,0},{86,0},{88,0},{89,0},{91,0},{92,0},{94,0},{95,0},
		{97,0},{98,0},{100,0},{101,0},{103,0},{104,0},{106,0},{107,0},{109,0},{110,0},{112,0},{114,0},{115,0},{117,0},{118,0},{120,0},
		{121,0},{123,0},{124,0},{126,0},{127,0},{127,1},{126,2},{126,3},{127,3},{127,4},{126,5},{126,6},{127,6},{127,7},{126,8},{126,9},
		{127,9},{127,10},{126,11},{126,12},{127,12},{127,13},{126,14},{125,15},{127,15},{126,16},{126,17},{127,17},{127,18},{126,19},{126,20},{127,20},
		{127,21},{126,22},{126,23},{127,23},{127,24},{126,25},{126,26},{127,26},{127,27},{126,28},{126,29},{127,29},{127,30},{126,31},{126,32},{127,32},
		{127,33},{126,34},{126,35},{127,35},{127,36},{126,37},{126,38},{127,38},{127,39},{126,40},{126,41},{127,41},{127,42},{126,43},{126,44},{127,44},
		{127,45},{126,46},{125,47},{127,47},{126,48},{126,49},{127,49},{127,50},{126,51},{126,52},{127,52},{127,53},{126,54},{126,55},{127,55},{127,56},
		{126,57},{126,58},{127,58},{127,59},{126,60},{126,61},{127,61},{127,62},{126,63},{125,64},{126,64},{126,65},{127,65},{127,66},{126,67},{126,68},
		{127,68},{127,69},{126,70},{126,71},{127,71},{127,72},{126,73},{126,74},{127,74},{127,75},{126,76},{125,77},{127,77},{126,78},{126,79},{127,79},
		{127,80},{126,81},{126,82},{127,82},{127,83},{126,84},{126,85},{127,85},{127,86},{126,87},{126,88},{127,88},{127,89},{126,90},{126,91},{127,91},
		{127,92},{126,93},{126,94},{127,94},{127,95},{126,96},{126,97},{127,97},{127,98},{126,99},{126,100},{127,100},{127,101},{126,102},{126,103},{127,103},
		{127,104},{126,105},{126,106},{127,106},{127,107},{126,108},{125,109},{127,109},{126,110},{126,111},{127,111},{127,112},{126,113},{126,114},{127,114},{127,115},
		{126,116},{126,117},{127,117},{127,118},{126,119},{126,120},{127,120},{127,121},{126,122},{126,123},{127,123},{127,124},{126,125},{126,126},{127,126},{127,127}
	};
	
	static void transcoder_init_bc7_mode5()
	{
#if 0
		// This is a little too much work to do at init time, so precompute it.
		for (int i = 0; i < 256; i++)
		{
			int lowest_e = 256;
			for (int lo = 0; lo < 128; lo++)
			{
				for (int hi = 0; hi < 128; hi++)
				{
					const int lo_e = (lo << 1) | (lo >> 6);
					const int hi_e = (hi << 1) | (hi >> 6);

					// Selector 1
					int v = (lo_e * (64 - 21) + hi_e * 21 + 32) >> 6;
					int e = abs(v - i);

					if (e < lowest_e)
					{
						g_bc7_m5_equals_1[i].m_hi = static_cast<uint8_t>(hi);
						g_bc7_m5_equals_1[i].m_lo = static_cast<uint8_t>(lo);

						lowest_e = e;
					}

				} // hi
								
			} // lo
			
			printf("{%u,%u},", g_bc7_m5_equals_1[i].m_hi, g_bc7_m5_equals_1[i].m_lo);
			if ((i & 15) == 15) printf("\n");
		}
#endif

		for (uint32_t i = 0; i < NUM_ETC1_TO_BC7_M5_SELECTOR_RANGES; i++)
		{
			uint32_t l = g_etc1_to_bc7_m5_selector_ranges[i].m_low;
			uint32_t h = g_etc1_to_bc7_m5_selector_ranges[i].m_high;
			g_etc1_to_bc7_m5_selector_range_index[l][h] = i;
		}

		for (uint32_t i = 0; i < NUM_ETC1_TO_BC7_M5A_SELECTOR_RANGES; i++)
		{
			uint32_t l = g_etc1_to_bc7_m5a_selector_ranges[i].m_low;
			uint32_t h = g_etc1_to_bc7_m5a_selector_ranges[i].m_high;
			g_etc1_to_bc7_m5a_selector_range_index[l][h] = i;
		}
	}

	static void convert_etc1s_to_bc7_m5_color(void* pDst, const endpoint* pEndpoints, const selector* pSelector)
	{
		bc7_mode_5* pDst_block = static_cast<bc7_mode_5*>(pDst);
				
		// First ensure the block is cleared to all 0's
		static_cast<uint64_t*>(pDst)[0] = 0;
		static_cast<uint64_t*>(pDst)[1] = 0;

		// Set alpha to 255
		pDst_block->m_lo.m_mode = 1 << 5;
		pDst_block->m_lo.m_a0 = 255;
		pDst_block->m_lo.m_a1_0 = 63;
		pDst_block->m_hi.m_a1_1 = 3;

		const uint32_t low_selector = pSelector->m_lo_selector;
		const uint32_t high_selector = pSelector->m_hi_selector;

		const uint32_t base_color_r = pEndpoints->m_color5.r;
		const uint32_t base_color_g = pEndpoints->m_color5.g;
		const uint32_t base_color_b = pEndpoints->m_color5.b;
		const uint32_t inten_table = pEndpoints->m_inten5;

		if (pSelector->m_num_unique_selectors == 1)
		{
			// Solid color block - use precomputed tables and set selectors to 1.
			uint32_t r, g, b;
			decoder_etc_block::get_block_color5(pEndpoints->m_color5, inten_table, low_selector, r, g, b);

			pDst_block->m_lo.m_r0 = g_bc7_m5_equals_1[r].m_lo;
			pDst_block->m_lo.m_g0 = g_bc7_m5_equals_1[g].m_lo;
			pDst_block->m_lo.m_b0 = g_bc7_m5_equals_1[b].m_lo;

			pDst_block->m_lo.m_r1 = g_bc7_m5_equals_1[r].m_hi;
			pDst_block->m_lo.m_g1 = g_bc7_m5_equals_1[g].m_hi;
			pDst_block->m_lo.m_b1 = g_bc7_m5_equals_1[b].m_hi;

			set_block_bits((uint8_t*)pDst, 0x2aaaaaab, 31, 66);
			return;
		}
		else if (pSelector->m_num_unique_selectors == 2)
		{
			// Only one or two unique selectors, so just switch to block truncation coding (BTC) to avoid quality issues on extreme blocks.
			color32 block_colors[4];

			decoder_etc_block::get_block_colors5(block_colors, color32(base_color_r, base_color_g, base_color_b, 255), inten_table);

			const uint32_t r0 = block_colors[low_selector].r;
			const uint32_t g0 = block_colors[low_selector].g;
			const uint32_t b0 = block_colors[low_selector].b;

			const uint32_t r1 = block_colors[high_selector].r;
			const uint32_t g1 = block_colors[high_selector].g;
			const uint32_t b1 = block_colors[high_selector].b;

			pDst_block->m_lo.m_r0 = r0 >> 1;
			pDst_block->m_lo.m_g0 = g0 >> 1;
			pDst_block->m_lo.m_b0 = b0 >> 1;

			pDst_block->m_lo.m_r1 = r1 >> 1;
			pDst_block->m_lo.m_g1 = g1 >> 1;
			pDst_block->m_lo.m_b1 = b1 >> 1;

			uint32_t output_low_selector = 0, output_bit_offset = 0, output_bits = 0;

			for (uint32_t y = 0; y < 4; y++)
			{
				for (uint32_t x = 0; x < 4; x++)
				{
					uint32_t s = pSelector->get_selector(x, y);
					uint32_t os = (s == low_selector) ? output_low_selector : (3 ^ output_low_selector);

					uint32_t num_bits = 2;

					if ((x | y) == 0)
					{
						if (os & 2)
						{
							pDst_block->m_lo.m_r0 = r1 >> 1;
							pDst_block->m_lo.m_g0 = g1 >> 1;
							pDst_block->m_lo.m_b0 = b1 >> 1;

							pDst_block->m_lo.m_r1 = r0 >> 1;
							pDst_block->m_lo.m_g1 = g0 >> 1;
							pDst_block->m_lo.m_b1 = b0 >> 1;

							output_low_selector = 3;
							os = 0;
						}

						num_bits = 1;
					}

					output_bits |= (os << output_bit_offset);
					output_bit_offset += num_bits;
				}
			}

			set_block_bits((uint8_t*)pDst, output_bits, 31, 66);
			return;
		}

		const uint32_t selector_range_table = g_etc1_to_bc7_m5_selector_range_index[low_selector][high_selector];

		//[32][8][RANGES][MAPPING]
		const etc1_to_bc7_m5_solution* pTable_r = &g_etc1_to_bc7_m5_color[(inten_table * 32 + base_color_r) * (NUM_ETC1_TO_BC7_M5_SELECTOR_RANGES * NUM_ETC1_TO_BC7_M5_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_BC7_M5_SELECTOR_MAPPINGS];
		const etc1_to_bc7_m5_solution* pTable_g = &g_etc1_to_bc7_m5_color[(inten_table * 32 + base_color_g) * (NUM_ETC1_TO_BC7_M5_SELECTOR_RANGES * NUM_ETC1_TO_BC7_M5_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_BC7_M5_SELECTOR_MAPPINGS];
		const etc1_to_bc7_m5_solution* pTable_b = &g_etc1_to_bc7_m5_color[(inten_table * 32 + base_color_b) * (NUM_ETC1_TO_BC7_M5_SELECTOR_RANGES * NUM_ETC1_TO_BC7_M5_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_BC7_M5_SELECTOR_MAPPINGS];

		uint32_t best_err = UINT_MAX;
		uint32_t best_mapping = 0;

		assert(NUM_ETC1_TO_BC7_M5_SELECTOR_MAPPINGS == 10);
#define DO_ITER(m) { uint32_t total_err = pTable_r[m].m_err + pTable_g[m].m_err + pTable_b[m].m_err; if (total_err < best_err) { best_err = total_err; best_mapping = m; } }
		DO_ITER(0); DO_ITER(1); DO_ITER(2); DO_ITER(3); DO_ITER(4);
		DO_ITER(5); DO_ITER(6); DO_ITER(7); DO_ITER(8); DO_ITER(9);
#undef DO_ITER

		const uint8_t* pSelectors_xlat = &g_etc1_to_bc7_m5_selector_mappings[best_mapping][0];

		uint32_t s_inv = 0;
		if (pSelectors_xlat[pSelector->get_selector(0, 0)] & 2)
		{
			pDst_block->m_lo.m_r0 = pTable_r[best_mapping].m_hi;
			pDst_block->m_lo.m_g0 = pTable_g[best_mapping].m_hi;
			pDst_block->m_lo.m_b0 = pTable_b[best_mapping].m_hi;

			pDst_block->m_lo.m_r1 = pTable_r[best_mapping].m_lo;
			pDst_block->m_lo.m_g1 = pTable_g[best_mapping].m_lo;
			pDst_block->m_lo.m_b1 = pTable_b[best_mapping].m_lo;
			
			s_inv = 3;
		}
		else
		{
			pDst_block->m_lo.m_r0 = pTable_r[best_mapping].m_lo;
			pDst_block->m_lo.m_g0 = pTable_g[best_mapping].m_lo;
			pDst_block->m_lo.m_b0 = pTable_b[best_mapping].m_lo;

			pDst_block->m_lo.m_r1 = pTable_r[best_mapping].m_hi;
			pDst_block->m_lo.m_g1 = pTable_g[best_mapping].m_hi;
			pDst_block->m_lo.m_b1 = pTable_b[best_mapping].m_hi;
		}

		uint32_t output_bits = 0, output_bit_ofs = 0;

		for (uint32_t y = 0; y < 4; y++)
		{
			for (uint32_t x = 0; x < 4; x++)
			{
				const uint32_t s = pSelector->get_selector(x, y);
				
				const uint32_t os = pSelectors_xlat[s] ^ s_inv;

				output_bits |= (os << output_bit_ofs);

				output_bit_ofs += (((x | y) == 0) ? 1 : 2);
			}
		}

		set_block_bits((uint8_t*)pDst, output_bits, 31, 66);
	}

	static void convert_etc1s_to_bc7_m5_alpha(void* pDst, const endpoint* pEndpoints, const selector* pSelector)
	{
		bc7_mode_5* pDst_block = static_cast<bc7_mode_5*>(pDst);

		const uint32_t low_selector = pSelector->m_lo_selector;
		const uint32_t high_selector = pSelector->m_hi_selector;

		const uint32_t base_color_r = pEndpoints->m_color5.r;
		const uint32_t inten_table = pEndpoints->m_inten5;

		if (pSelector->m_num_unique_selectors == 1)
		{
			uint32_t r;
			decoder_etc_block::get_block_color5_r(pEndpoints->m_color5, inten_table, low_selector, r);

			pDst_block->m_lo.m_a0 = r;
			pDst_block->m_lo.m_a1_0 = r & 63;
			pDst_block->m_hi.m_a1_1 = r >> 6;
					  
			return;
		}
		else if (pSelector->m_num_unique_selectors == 2)
		{
			// Only one or two unique selectors, so just switch to block truncation coding (BTC) to avoid quality issues on extreme blocks.
			int block_colors[4];

			decoder_etc_block::get_block_colors5_g(block_colors, pEndpoints->m_color5, inten_table);

			pDst_block->m_lo.m_a0 = block_colors[low_selector];
			pDst_block->m_lo.m_a1_0 = block_colors[high_selector] & 63;
			pDst_block->m_hi.m_a1_1 = block_colors[high_selector] >> 6;

			uint32_t output_low_selector = 0, output_bit_offset = 0, output_bits = 0;

			for (uint32_t y = 0; y < 4; y++)
			{
				for (uint32_t x = 0; x < 4; x++)
				{
					const uint32_t s = pSelector->get_selector(x, y);
					uint32_t os = (s == low_selector) ? output_low_selector : (3 ^ output_low_selector);

					uint32_t num_bits = 2;

					if ((x | y) == 0)
					{
						if (os & 2)
						{
							pDst_block->m_lo.m_a0 = block_colors[high_selector];
							pDst_block->m_lo.m_a1_0 = block_colors[low_selector] & 63;
							pDst_block->m_hi.m_a1_1 = block_colors[low_selector] >> 6;

							output_low_selector = 3;
							os = 0;
						}

						num_bits = 1;
					}

					output_bits |= (os << output_bit_offset);
					output_bit_offset += num_bits;
				}
			}

			set_block_bits((uint8_t*)pDst, output_bits, 31, 97);
			return;
		}

		const uint32_t selector_range_table = g_etc1_to_bc7_m5a_selector_range_index[low_selector][high_selector];
						
		const etc1_g_to_bc7_m5a_conversion* pTable = &g_etc1_g_to_bc7_m5a[inten_table * (32 * NUM_ETC1_TO_BC7_M5A_SELECTOR_RANGES) + base_color_r * NUM_ETC1_TO_BC7_M5A_SELECTOR_RANGES + selector_range_table];

		pDst_block->m_lo.m_a0 = pTable->m_lo;
		pDst_block->m_lo.m_a1_0 = pTable->m_hi & 63;
		pDst_block->m_hi.m_a1_1 = pTable->m_hi >> 6;

		uint32_t output_bit_offset = 0, output_bits = 0, selector_trans = pTable->m_trans;

		for (uint32_t y = 0; y < 4; y++)
		{
			for (uint32_t x = 0; x < 4; x++)
			{
				const uint32_t s = pSelector->get_selector(x, y);
				uint32_t os = (selector_trans >> (s * 2)) & 3;

				uint32_t num_bits = 2;

				if ((x | y) == 0)
				{
					if (os & 2)
					{
						pDst_block->m_lo.m_a0 = pTable->m_hi;
						pDst_block->m_lo.m_a1_0 = pTable->m_lo & 63;
						pDst_block->m_hi.m_a1_1 = pTable->m_lo >> 6;

						selector_trans ^= 0xFF;
						os ^= 3;
					}

					num_bits = 1;
				}

				output_bits |= (os << output_bit_offset);
				output_bit_offset += num_bits;
			}
		}

		set_block_bits((uint8_t*)pDst, output_bits, 31, 97);
	}

	static inline vec3F rgb_to_ycocg(const vec3F& rgb)
	{
		return vec3F(rgb.dot(vec3F(0.25f, 0.5f, 0.25f)), rgb.dot(vec3F(0.5f, 0.0f, -0.5f)), rgb.dot(vec3F(-0.25f, 0.5f, -0.25f)));
	}

	static inline vec2F rgb_to_cocg(const vec3F& rgb)
	{
		return vec2F(rgb.dot(vec3F(0.5f, 0.0f, -0.5f)), rgb.dot(vec3F(-0.25f, 0.5f, -0.25f)));
	}

	static inline vec3F ycocg_to_rgb(const vec3F& ycocg)
	{
		return vec3F(ycocg.dot(vec3F(1.0f, 1.0f, -1.0f)), ycocg.dot(vec3F(1.0f, 0.0f, 1.0f)), ycocg.dot(vec3F(1.0f, -1.0f, -1.0f)));
	}

	static inline vec3F color32_to_vec3F(const color32& c)
	{
		return vec3F(c.r, c.g, c.b);
	}

	static inline vec3F color5_to_ycocg(const endpoint& e)
	{
		const int r = (e.m_color5[0] << 3) | (e.m_color5[0] >> 2);
		const int g = (e.m_color5[1] << 3) | (e.m_color5[1] >> 2);
		const int b = (e.m_color5[2] << 3) | (e.m_color5[2] >> 2);
		return rgb_to_ycocg(vec3F((float)r, (float)g, (float)b));
	}

	static inline vec2F color5_to_cocg(const endpoint& e)
	{
		const int r = (e.m_color5[0] << 3) | (e.m_color5[0] >> 2);
		const int g = (e.m_color5[1] << 3) | (e.m_color5[1] >> 2);
		const int b = (e.m_color5[2] << 3) | (e.m_color5[2] >> 2);
		return rgb_to_cocg(vec3F((float)r, (float)g, (float)b));
	}

	static inline uint32_t bc7_7_to_8(uint32_t v)
	{
		assert(v < 128);
		return (v << 1) | (v >> 6);
	}

	static inline uint32_t bc7_interp2(uint32_t l, uint32_t h, uint32_t w)
	{
		assert(w < 4);
		return (l * (64 - basist::g_bc7_weights2[w]) + h * basist::g_bc7_weights2[w] + 32) >> 6;
	}

	static inline vec2F get_endpoint_cocg_clamped(int bx, int by, const basisu::vector2D<uint16_t>& decoded_endpoints, const endpoint* pEndpoints)
	{
		const uint32_t endpoint_index = decoded_endpoints.at_clamped(bx, by);
		return color5_to_cocg(pEndpoints[endpoint_index]);
	}

	static void chroma_filter_bc7_mode5(const basisu::vector2D<uint16_t>& decoded_endpoints, void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y, uint32_t output_row_pitch_in_blocks_or_pixels, const endpoint *pEndpoints)
	{
		const bool hq_bc7_mode_5_encoder_mode = false;

		const int CHROMA_THRESH = 10;
		
		uint32_t total_filtered_blocks = 0;
		BASISU_NOTE_UNUSED(total_filtered_blocks);

		for (int by = 0; by < (int)num_blocks_y; by++)
		{
			for (int bx = 0; bx < (int)num_blocks_x; bx++)
			{
				vec2F center_cocg(color5_to_cocg(pEndpoints[decoded_endpoints(bx, by)]));
		
				//bool filter_flag = false;
				for (int dy = -1; dy <= 1; dy++)
				{
					const int oy = by + dy;
					if ((oy < 0) || (oy >= (int)num_blocks_y))
						continue;

					for (int dx = -1; dx <= 1; dx++)
					{
						if ((dx | dy) == 0)
							continue;

						const int ox = bx + dx;
						if ((ox < 0) || (ox >= (int)num_blocks_x))
							continue;

						vec2F nearby_cocg(color5_to_cocg(pEndpoints[decoded_endpoints(ox, oy)]));

						float delta_co = fabsf(nearby_cocg[0] - center_cocg[0]);
						float delta_cg = fabsf(nearby_cocg[1] - center_cocg[1]);

						if ((delta_co > CHROMA_THRESH) || (delta_cg > CHROMA_THRESH))
						{
							//filter_flag = true;
							goto do_filter;
						}

					} // dx
				} // dy

				continue;

			do_filter:;

				total_filtered_blocks++;

				bc7_mode_5* pDst_block = (bc7_mode_5*)(static_cast<uint8_t*>(pDst_blocks) + (bx + by * output_row_pitch_in_blocks_or_pixels) * sizeof(bc7_mode_5));
				
				//memset(pDst_block, 0x80, 16);

				int lr = bc7_7_to_8(pDst_block->m_lo.m_r0);
				int lg = bc7_7_to_8(pDst_block->m_lo.m_g0);
				int lb = bc7_7_to_8(pDst_block->m_lo.m_b0);

				int hr = bc7_7_to_8(pDst_block->m_lo.m_r1);
				int hg = bc7_7_to_8(pDst_block->m_lo.m_g1);
				int hb = bc7_7_to_8(pDst_block->m_lo.m_b1);

				float y_vals[4];
				for (uint32_t i = 0; i < 4; i++)
				{
					int cr = bc7_interp2(lr, hr, i);
					int cg = bc7_interp2(lg, hg, i);
					int cb = bc7_interp2(lb, hb, i);
					y_vals[i] = (float)cr * .25f + (float)cg * .5f + (float)cb * .25f;
				} // i

				uint64_t sel_bits = pDst_block->m_hi_bits >> 2;

				float block_y_vals[16]; // [y][x]
				float y_sum = 0.0f, y_sum_sq = 0.0f;
				
				for (uint32_t i = 0; i < 16; i++)
				{
					uint32_t sel = sel_bits & (i ? 3 : 1);
					sel_bits >>= (i ? 2 : 1);
					float y = y_vals[sel];
					block_y_vals[i] = y;
					y_sum += y;
					y_sum_sq += y * y;
					
				} // i

				const float S = 1.0f / 16.0f;
				float y_var = (y_sum_sq * S) - basisu::squaref(y_sum * S);

				// Don't bother if the block is too smooth.
				const float Y_VAR_SKIP_THRESH = 3.0f;
				if (y_var < Y_VAR_SKIP_THRESH)
					continue;

				color32 block_to_pack[16];

				for (int bpy = 0; bpy < 4; bpy++)
				{
					const int uby = by + ((bpy - 2) >> 2);

					for (int bpx = 0; bpx < 4; bpx++)
					{
						const float fx = ((float)((bpx + 2) & 3) + .5f) * (1.0f / 4.0f);
						const float fy = ((float)((bpy + 2) & 3) + .5f) * (1.0f / 4.0f);

						const int ubx = bx + ((bpx - 2) >> 2);
												
						vec2F a(get_endpoint_cocg_clamped(ubx, uby, decoded_endpoints, pEndpoints));
						vec2F b(get_endpoint_cocg_clamped(ubx + 1, uby, decoded_endpoints, pEndpoints));
						vec2F c(get_endpoint_cocg_clamped(ubx, uby + 1, decoded_endpoints, pEndpoints));
						vec2F d(get_endpoint_cocg_clamped(ubx + 1, uby + 1, decoded_endpoints, pEndpoints));

						assert((fx >= 0) && (fx <= 1.0f) && (fy >= 0) && (fy <= 1.0f));
												
						// TODO: Could merge this into 4 muls on each corner by weights
						vec2F ab = vec2F::lerp(a, b, fx);
						vec2F cd = vec2F::lerp(c, d, fx);
						vec2F f = vec2F::lerp(ab, cd, fy);

						vec3F final_ycocg(block_y_vals[bpx + bpy * 4], f[0], f[1]);

						vec3F final_conv(ycocg_to_rgb(final_ycocg));
						final_conv.clamp(0.0f, 255.0f);

						block_to_pack[bpx + bpy * 4].set_noclamp_rgba((int)(.5f + final_conv[0]), (int)(.5f + final_conv[1]), (int)(.5f + final_conv[2]), 255);

					} // x
				} // y

				bc7_mode_5_encoder::encode_bc7_mode_5_block(pDst_block, block_to_pack, hq_bc7_mode_5_encoder_mode);
				
			} // bx
		} // by

		//basisu::fmt_printf("Chroma thresh: {}, Total blocks to filter: {} out of {} {}\n", CHROMA_THRESH, total_filtered_blocks, num_blocks_x * num_blocks_y, (float)total_filtered_blocks * 100.0f / (num_blocks_x * num_blocks_y));
	}
#endif // BASISD_SUPPORT_BC7_MODE5

#if BASISD_SUPPORT_ETC2_EAC_A8 || BASISD_SUPPORT_UASTC
	static const uint8_t g_etc2_eac_a8_sel4[6] = { 0x92, 0x49, 0x24, 0x92, 0x49, 0x24 };
#endif

#if BASISD_SUPPORT_ETC2_EAC_A8
	static void convert_etc1s_to_etc2_eac_a8(eac_block* pDst_block, const endpoint* pEndpoints, const selector* pSelector)
	{
		const uint32_t low_selector = pSelector->m_lo_selector;
		const uint32_t high_selector = pSelector->m_hi_selector;

		const color32& base_color = pEndpoints->m_color5;
		const uint32_t inten_table = pEndpoints->m_inten5;

		if (low_selector == high_selector)
		{
			uint32_t r;
			decoder_etc_block::get_block_color5_r(base_color, inten_table, low_selector, r);

			// Constant alpha block
			// Select table 13, use selector 4 (0), set multiplier to 1 and base color g
			pDst_block->m_base = r;
			pDst_block->m_table = 13;
			pDst_block->m_multiplier = 1;

			// selectors are all 4's
			memcpy(pDst_block->m_selectors, g_etc2_eac_a8_sel4, sizeof(g_etc2_eac_a8_sel4));

			return;
		}

		uint32_t selector_range_table = 0;
		for (selector_range_table = 0; selector_range_table < NUM_ETC2_EAC_SELECTOR_RANGES; selector_range_table++)
			if ((low_selector == s_etc2_eac_selector_ranges[selector_range_table].m_low) && (high_selector == s_etc2_eac_selector_ranges[selector_range_table].m_high))
				break;
		if (selector_range_table >= NUM_ETC2_EAC_SELECTOR_RANGES)
			selector_range_table = 0;

		const etc1_g_to_eac_conversion* pTable_entry = &s_etc1_g_to_etc2_a8[base_color.r + inten_table * 32][selector_range_table];

		pDst_block->m_base = pTable_entry->m_base;
		pDst_block->m_table = pTable_entry->m_table_mul >> 4;
		pDst_block->m_multiplier = pTable_entry->m_table_mul & 15;

		uint64_t selector_bits = 0;

		for (uint32_t y = 0; y < 4; y++)
		{
			for (uint32_t x = 0; x < 4; x++)
			{
				uint32_t s = pSelector->get_selector(x, y);

				uint32_t ds = (pTable_entry->m_trans >> (s * 3)) & 7;

				const uint32_t dst_ofs = 45 - (y + x * 4) * 3;
				selector_bits |= (static_cast<uint64_t>(ds) << dst_ofs);
			}
		}

		pDst_block->set_selector_bits(selector_bits);
	}
#endif // BASISD_SUPPORT_ETC2_EAC_A8

#if BASISD_SUPPORT_ETC2_EAC_RG11
	static const etc1_g_to_eac_conversion s_etc1_g_to_etc2_r11[32 * 8][NUM_ETC2_EAC_SELECTOR_RANGES] =
	{
		{{0,1,3328},{0,1,3328},{0,16,457},{0,16,456}},
		{{0,226,3936},{0,226,3936},{0,17,424},{8,0,472}},
		{{6,178,4012},{6,178,4008},{0,146,501},{16,0,472}},
		{{14,178,4012},{14,178,4008},{8,146,501},{24,0,472}},
		{{23,178,4012},{23,178,4008},{17,146,501},{33,0,472}},
		{{31,178,4012},{31,178,4008},{25,146,501},{41,0,472}},
		{{39,178,4012},{39,178,4008},{33,146,501},{49,0,472}},
		{{47,178,4012},{47,178,4008},{41,146,501},{27,228,496}},
		{{56,178,4012},{56,178,4008},{50,146,501},{36,228,496}},
		{{64,178,4012},{64,178,4008},{58,146,501},{44,228,496}},
		{{72,178,4012},{72,178,4008},{66,146,501},{52,228,496}},
		{{80,178,4012},{80,178,4008},{74,146,501},{60,228,496}},
		{{89,178,4012},{89,178,4008},{83,146,501},{69,228,496}},
		{{97,178,4012},{97,178,4008},{91,146,501},{77,228,496}},
		{{105,178,4012},{105,178,4008},{99,146,501},{85,228,496}},
		{{113,178,4012},{113,178,4008},{107,146,501},{93,228,496}},
		{{122,178,4012},{122,178,4008},{116,146,501},{102,228,496}},
		{{130,178,4012},{130,178,4008},{124,146,501},{110,228,496}},
		{{138,178,4012},{138,178,4008},{132,146,501},{118,228,496}},
		{{146,178,4012},{146,178,4008},{140,146,501},{126,228,496}},
		{{155,178,4012},{155,178,4008},{149,146,501},{135,228,496}},
		{{163,178,4012},{163,178,4008},{157,146,501},{143,228,496}},
		{{171,178,4012},{171,178,4008},{165,146,501},{151,228,496}},
		{{179,178,4012},{179,178,4008},{173,146,501},{159,228,496}},
		{{188,178,4012},{188,178,4008},{182,146,501},{168,228,496}},
		{{196,178,4012},{196,178,4008},{190,146,501},{176,228,496}},
		{{204,178,4012},{204,178,4008},{198,146,501},{184,228,496}},
		{{212,178,4012},{212,178,4008},{206,146,501},{192,228,496}},
		{{221,178,4012},{221,178,4008},{215,146,501},{201,228,496}},
		{{229,178,4012},{229,178,4008},{223,146,501},{209,228,496}},
		{{235,66,4012},{221,100,4008},{231,146,501},{217,228,496}},
		{{211,102,4085},{254,32,4040},{211,102,501},{254,32,456}},
		{{0,2,3328},{0,2,3328},{0,1,320},{0,1,320}},
		{{7,162,3905},{7,162,3904},{0,17,480},{0,17,480}},
		{{15,162,3906},{15,162,3904},{1,117,352},{1,117,352}},
		{{23,162,3906},{23,162,3904},{5,34,500},{4,53,424}},
		{{32,162,3906},{32,162,3904},{14,34,500},{3,69,424}},
		{{40,162,3906},{40,162,3904},{22,34,500},{1,133,496}},
		{{48,162,3906},{48,162,3904},{30,34,500},{4,85,496}},
		{{56,162,3906},{56,162,3904},{38,34,500},{12,85,496}},
		{{65,162,3906},{65,162,3904},{47,34,500},{1,106,424}},
		{{73,162,3906},{73,162,3904},{55,34,500},{9,106,424}},
		{{81,162,3906},{81,162,3904},{63,34,500},{7,234,496}},
		{{89,162,3906},{89,162,3904},{71,34,500},{15,234,496}},
		{{98,162,3906},{98,162,3904},{80,34,500},{24,234,496}},
		{{106,162,3906},{106,162,3904},{88,34,500},{32,234,496}},
		{{114,162,3906},{114,162,3904},{96,34,500},{40,234,496}},
		{{122,162,3906},{122,162,3904},{104,34,500},{48,234,496}},
		{{131,162,3906},{131,162,3904},{113,34,500},{57,234,496}},
		{{139,162,3906},{139,162,3904},{121,34,500},{65,234,496}},
		{{147,162,3906},{147,162,3904},{129,34,500},{73,234,496}},
		{{155,162,3906},{155,162,3904},{137,34,500},{81,234,496}},
		{{164,162,3906},{164,162,3904},{146,34,500},{90,234,496}},
		{{172,162,3906},{172,162,3904},{154,34,500},{98,234,496}},
		{{180,162,3906},{180,162,3904},{162,34,500},{106,234,496}},
		{{188,162,3906},{188,162,3904},{170,34,500},{114,234,496}},
		{{197,162,3906},{197,162,3904},{179,34,500},{123,234,496}},
		{{205,162,3906},{205,162,3904},{187,34,500},{131,234,496}},
		{{213,162,3906},{213,162,3904},{195,34,500},{139,234,496}},
		{{221,162,3906},{221,162,3904},{203,34,500},{147,234,496}},
		{{230,162,3906},{230,162,3904},{212,34,500},{156,234,496}},
		{{238,162,3906},{174,106,4008},{220,34,500},{164,234,496}},
		{{240,178,4001},{182,106,4008},{228,34,500},{172,234,496}},
		{{166,108,4085},{115,31,4080},{166,108,501},{115,31,496}},
		{{1,68,3328},{1,68,3328},{0,1,384},{0,1,384}},
		{{1,51,3968},{1,51,3968},{0,2,384},{0,2,384}},
		{{21,18,3851},{21,18,3848},{1,50,488},{1,50,488}},
		{{26,195,3851},{29,18,3848},{0,67,488},{0,67,488}},
		{{35,195,3851},{38,18,3848},{12,115,488},{0,3,496}},
		{{43,195,3851},{46,18,3848},{20,115,488},{2,6,424}},
		{{51,195,3851},{54,18,3848},{36,66,482},{4,22,424}},
		{{59,195,3851},{62,18,3848},{44,66,482},{3,73,424}},
		{{68,195,3851},{71,18,3848},{53,66,482},{3,22,496}},
		{{76,195,3851},{79,18,3848},{61,66,482},{2,137,496}},
		{{84,195,3851},{87,18,3848},{69,66,482},{1,89,496}},
		{{92,195,3851},{95,18,3848},{77,66,482},{9,89,496}},
		{{101,195,3851},{104,18,3848},{86,66,482},{18,89,496}},
		{{109,195,3851},{112,18,3848},{94,66,482},{26,89,496}},
		{{117,195,3851},{120,18,3848},{102,66,482},{34,89,496}},
		{{125,195,3851},{128,18,3848},{110,66,482},{42,89,496}},
		{{134,195,3851},{137,18,3848},{119,66,482},{51,89,496}},
		{{141,195,3907},{145,18,3848},{127,66,482},{59,89,496}},
		{{149,195,3907},{153,18,3848},{135,66,482},{67,89,496}},
		{{157,195,3907},{161,18,3848},{143,66,482},{75,89,496}},
		{{166,195,3907},{170,18,3848},{152,66,482},{84,89,496}},
		{{174,195,3907},{178,18,3848},{160,66,482},{92,89,496}},
		{{182,195,3907},{186,18,3848},{168,66,482},{100,89,496}},
		{{190,195,3907},{194,18,3848},{176,66,482},{108,89,496}},
		{{199,195,3907},{203,18,3848},{185,66,482},{117,89,496}},
		{{207,195,3907},{211,18,3848},{193,66,482},{125,89,496}},
		{{215,195,3907},{219,18,3848},{201,66,482},{133,89,496}},
		{{223,195,3907},{227,18,3848},{209,66,482},{141,89,496}},
		{{232,195,3907},{168,89,4008},{218,66,482},{150,89,496}},
		{{236,18,3907},{176,89,4008},{226,66,482},{158,89,496}},
		{{158,90,4085},{103,31,4080},{158,90,501},{103,31,496}},
		{{166,90,4085},{111,31,4080},{166,90,501},{111,31,496}},
		{{0,70,3328},{0,70,3328},{0,17,448},{0,17,448}},
		{{0,117,3904},{0,117,3904},{0,35,384},{0,35,384}},
		{{13,165,3905},{13,165,3904},{2,211,480},{2,211,480}},
		{{21,165,3906},{21,165,3904},{1,51,488},{1,51,488}},
		{{30,165,3906},{30,165,3904},{7,61,352},{7,61,352}},
		{{38,165,3906},{38,165,3904},{2,125,352},{2,125,352}},
		{{46,165,3906},{46,165,3904},{1,37,500},{10,125,352}},
		{{54,165,3906},{54,165,3904},{9,37,500},{5,61,424}},
		{{63,165,3906},{63,165,3904},{18,37,500},{1,189,424}},
		{{71,165,3906},{71,165,3904},{26,37,500},{9,189,424}},
		{{79,165,3906},{79,165,3904},{34,37,500},{4,77,424}},
		{{87,165,3906},{87,165,3904},{42,37,500},{12,77,424}},
		{{96,165,3906},{96,165,3904},{51,37,500},{8,93,424}},
		{{104,165,3906},{104,165,3904},{59,37,500},{3,141,496}},
		{{112,165,3906},{112,165,3904},{68,37,500},{11,141,496}},
		{{120,165,3906},{120,165,3904},{76,37,500},{6,93,496}},
		{{129,165,3906},{129,165,3904},{85,37,500},{15,93,496}},
		{{70,254,4012},{137,165,3904},{93,37,500},{23,93,496}},
		{{145,165,3906},{145,165,3904},{101,37,500},{31,93,496}},
		{{86,254,4012},{153,165,3904},{109,37,500},{39,93,496}},
		{{163,165,3906},{162,165,3904},{118,37,500},{48,93,496}},
		{{171,165,3906},{170,165,3904},{126,37,500},{56,93,496}},
		{{179,165,3906},{178,165,3904},{134,37,500},{64,93,496}},
		{{187,165,3906},{187,165,3904},{142,37,500},{72,93,496}},
		{{196,165,3906},{196,165,3904},{151,37,500},{81,93,496}},
		{{204,165,3906},{204,165,3904},{159,37,500},{89,93,496}},
		{{212,165,3906},{136,77,4008},{167,37,500},{97,93,496}},
		{{220,165,3906},{131,93,4008},{175,37,500},{105,93,496}},
		{{214,181,4001},{140,93,4008},{184,37,500},{114,93,496}},
		{{222,181,4001},{148,93,4008},{192,37,500},{122,93,496}},
		{{115,95,4085},{99,31,4080},{115,95,501},{99,31,496}},
		{{123,95,4085},{107,31,4080},{123,95,501},{107,31,496}},
		{{0,102,3840},{0,102,3840},{0,18,384},{0,18,384}},
		{{5,167,3904},{5,167,3904},{0,13,256},{0,13,256}},
		{{4,54,3968},{4,54,3968},{1,67,448},{1,67,448}},
		{{30,198,3850},{30,198,3848},{0,3,480},{0,3,480}},
		{{39,198,3850},{39,198,3848},{3,52,488},{3,52,488}},
		{{47,198,3851},{47,198,3848},{3,4,488},{3,4,488}},
		{{55,198,3851},{55,198,3848},{1,70,488},{1,70,488}},
		{{53,167,3906},{63,198,3848},{3,22,488},{3,22,488}},
		{{62,167,3906},{72,198,3848},{24,118,488},{0,6,496}},
		{{70,167,3906},{80,198,3848},{32,118,488},{2,89,488}},
		{{78,167,3906},{88,198,3848},{40,118,488},{1,73,496}},
		{{86,167,3906},{96,198,3848},{48,118,488},{0,28,424}},
		{{95,167,3906},{105,198,3848},{57,118,488},{9,28,424}},
		{{103,167,3906},{113,198,3848},{65,118,488},{5,108,496}},
		{{111,167,3906},{121,198,3848},{73,118,488},{13,108,496}},
		{{119,167,3906},{129,198,3848},{81,118,488},{21,108,496}},
		{{128,167,3906},{138,198,3848},{90,118,488},{6,28,496}},
		{{136,167,3906},{146,198,3848},{98,118,488},{14,28,496}},
		{{145,167,3906},{154,198,3848},{106,118,488},{22,28,496}},
		{{153,167,3906},{162,198,3848},{114,118,488},{30,28,496}},
		{{162,167,3906},{171,198,3848},{123,118,488},{39,28,496}},
		{{170,167,3906},{179,198,3848},{131,118,488},{47,28,496}},
		{{178,167,3906},{187,198,3848},{139,118,488},{55,28,496}},
		{{186,167,3906},{195,198,3848},{147,118,488},{63,28,496}},
		{{194,167,3906},{120,12,4008},{156,118,488},{72,28,496}},
		{{206,198,3907},{116,28,4008},{164,118,488},{80,28,496}},
		{{214,198,3907},{124,28,4008},{172,118,488},{88,28,496}},
		{{222,198,3395},{132,28,4008},{180,118,488},{96,28,496}},
		{{207,134,4001},{141,28,4008},{189,118,488},{105,28,496}},
		{{95,30,4085},{86,31,4080},{95,30,501},{86,31,496}},
		{{103,30,4085},{94,31,4080},{103,30,501},{94,31,496}},
		{{111,30,4085},{102,31,4080},{111,30,501},{102,31,496}},
		{{0,104,3840},{0,104,3840},{0,18,448},{0,18,448}},
		{{4,39,3904},{4,39,3904},{0,4,384},{0,4,384}},
		{{0,56,3968},{0,56,3968},{0,84,448},{0,84,448}},
		{{6,110,3328},{6,110,3328},{0,20,448},{0,20,448}},
		{{41,200,3850},{41,200,3848},{1,4,480},{1,4,480}},
		{{49,200,3850},{49,200,3848},{1,8,416},{1,8,416}},
		{{57,200,3851},{57,200,3848},{1,38,488},{1,38,488}},
		{{65,200,3851},{65,200,3848},{1,120,488},{1,120,488}},
		{{74,200,3851},{74,200,3848},{2,72,488},{2,72,488}},
		{{68,6,3907},{82,200,3848},{2,24,488},{2,24,488}},
		{{77,6,3907},{90,200,3848},{26,120,488},{10,24,488}},
		{{97,63,3330},{98,200,3848},{34,120,488},{2,8,496}},
		{{106,63,3330},{107,200,3848},{43,120,488},{3,92,488}},
		{{114,63,3330},{115,200,3848},{51,120,488},{11,92,488}},
		{{122,63,3330},{123,200,3848},{59,120,488},{7,76,496}},
		{{130,63,3330},{131,200,3848},{67,120,488},{15,76,496}},
		{{139,63,3330},{140,200,3848},{76,120,488},{24,76,496}},
		{{147,63,3330},{148,200,3848},{84,120,488},{32,76,496}},
		{{155,63,3330},{156,200,3848},{92,120,488},{40,76,496}},
		{{164,63,3330},{164,200,3848},{100,120,488},{48,76,496}},
		{{173,63,3330},{173,200,3848},{109,120,488},{57,76,496}},
		{{184,6,3851},{181,200,3848},{117,120,488},{65,76,496}},
		{{192,6,3851},{133,28,3936},{125,120,488},{73,76,496}},
		{{189,200,3907},{141,28,3936},{133,120,488},{81,76,496}},
		{{198,200,3907},{138,108,4000},{142,120,488},{90,76,496}},
		{{206,200,3907},{146,108,4000},{150,120,488},{98,76,496}},
		{{214,200,3395},{154,108,4000},{158,120,488},{106,76,496}},
		{{190,136,4001},{162,108,4000},{166,120,488},{114,76,496}},
		{{123,30,4076},{87,15,4080},{123,30,492},{87,15,496}},
		{{117,110,4084},{80,31,4080},{117,110,500},{80,31,496}},
		{{125,110,4084},{88,31,4080},{125,110,500},{88,31,496}},
		{{133,110,4084},{96,31,4080},{133,110,500},{96,31,496}},
		{{9,56,3904},{9,56,3904},{0,67,448},{0,67,448}},
		{{1,8,3904},{1,8,3904},{1,84,448},{1,84,448}},
		{{1,124,3904},{1,124,3904},{0,39,384},{0,39,384}},
		{{9,124,3904},{9,124,3904},{1,4,448},{1,4,448}},
		{{6,76,3904},{6,76,3904},{0,70,448},{0,70,448}},
		{{62,6,3859},{62,6,3856},{2,38,480},{2,38,480}},
		{{70,6,3859},{70,6,3856},{5,43,416},{5,43,416}},
		{{78,6,3859},{78,6,3856},{2,11,416},{2,11,416}},
		{{87,6,3859},{87,6,3856},{0,171,488},{0,171,488}},
		{{67,8,3906},{95,6,3856},{8,171,488},{8,171,488}},
		{{75,8,3907},{103,6,3856},{5,123,488},{5,123,488}},
		{{83,8,3907},{111,6,3856},{2,75,488},{2,75,488}},
		{{92,8,3907},{120,6,3856},{0,27,488},{0,27,488}},
		{{100,8,3907},{128,6,3856},{8,27,488},{8,27,488}},
		{{120,106,3843},{136,6,3856},{99,6,387},{16,27,488}},
		{{128,106,3843},{144,6,3856},{107,6,387},{2,11,496}},
		{{137,106,3843},{153,6,3856},{117,6,387},{11,11,496}},
		{{145,106,3843},{161,6,3856},{125,6,387},{19,11,496}},
		{{163,8,3851},{137,43,3904},{133,6,387},{27,11,496}},
		{{171,8,3851},{145,43,3904},{141,6,387},{35,11,496}},
		{{180,8,3851},{110,11,4000},{150,6,387},{44,11,496}},
		{{188,8,3851},{118,11,4000},{158,6,387},{52,11,496}},
		{{172,72,3907},{126,11,4000},{166,6,387},{60,11,496}},
		{{174,6,3971},{134,11,4000},{174,6,387},{68,11,496}},
		{{183,6,3971},{143,11,4000},{183,6,387},{77,11,496}},
		{{191,6,3971},{151,11,4000},{191,6,387},{85,11,496}},
		{{199,6,3971},{159,11,4000},{199,6,387},{93,11,496}},
		{{92,12,4084},{69,15,4080},{92,12,500},{69,15,496}},
		{{101,12,4084},{78,15,4080},{101,12,500},{78,15,496}},
		{{110,12,4084},{86,15,4080},{110,12,500},{86,15,496}},
		{{118,12,4084},{79,31,4080},{118,12,500},{79,31,496}},
		{{126,12,4084},{87,31,4080},{126,12,500},{87,31,496}},
		{{71,8,3602},{71,8,3600},{2,21,384},{2,21,384}},
		{{79,8,3611},{79,8,3608},{0,69,448},{0,69,448}},
		{{87,8,3611},{87,8,3608},{0,23,384},{0,23,384}},
		{{95,8,3611},{95,8,3608},{1,5,448},{1,5,448}},
		{{104,8,3611},{104,8,3608},{0,88,448},{0,88,448}},
		{{112,8,3611},{112,8,3608},{0,72,448},{0,72,448}},
		{{120,8,3611},{121,8,3608},{36,21,458},{36,21,456}},
		{{133,47,3091},{129,8,3608},{44,21,458},{44,21,456}},
		{{142,47,3091},{138,8,3608},{53,21,459},{53,21,456}},
		{{98,12,3850},{98,12,3848},{61,21,459},{61,21,456}},
		{{106,12,3850},{106,12,3848},{10,92,480},{69,21,456}},
		{{114,12,3851},{114,12,3848},{18,92,480},{77,21,456}},
		{{123,12,3851},{123,12,3848},{3,44,488},{86,21,456}},
		{{95,12,3906},{95,12,3904},{11,44,488},{94,21,456}},
		{{103,12,3906},{103,12,3904},{19,44,488},{102,21,456}},
		{{111,12,3907},{111,12,3904},{27,44,489},{110,21,456}},
		{{120,12,3907},{120,12,3904},{36,44,489},{119,21,456}},
		{{128,12,3907},{128,12,3904},{44,44,489},{127,21,456}},
		{{136,12,3907},{136,12,3904},{52,44,489},{135,21,456}},
		{{144,12,3907},{144,12,3904},{60,44,490},{144,21,456}},
		{{153,12,3907},{153,12,3904},{69,44,490},{153,21,456}},
		{{161,12,3395},{149,188,3968},{77,44,490},{161,21,456}},
		{{169,12,3395},{199,21,3928},{85,44,490},{169,21,456}},
		{{113,95,4001},{202,69,3992},{125,8,483},{177,21,456}},
		{{122,95,4001},{201,21,3984},{134,8,483},{186,21,456}},
		{{143,8,4067},{209,21,3984},{142,8,483},{194,21,456}},
		{{151,8,4067},{47,15,4080},{151,8,483},{47,15,496}},
		{{159,8,4067},{55,15,4080},{159,8,483},{55,15,496}},
		{{168,8,4067},{64,15,4080},{168,8,483},{64,15,496}},
		{{160,40,4075},{72,15,4080},{160,40,491},{72,15,496}},
		{{168,40,4075},{80,15,4080},{168,40,491},{80,15,496}},
		{{144,8,4082},{88,15,4080},{144,8,498},{88,15,496}},
	};

	static void convert_etc1s_to_etc2_eac_r11(eac_block* pDst_block, const endpoint* pEndpoints, const selector* pSelector)
	{
		const uint32_t low_selector = pSelector->m_lo_selector;
		const uint32_t high_selector = pSelector->m_hi_selector;

		const color32& base_color = pEndpoints->m_color5;
		const uint32_t inten_table = pEndpoints->m_inten5;

		if (low_selector == high_selector)
		{
			uint32_t r;
			decoder_etc_block::get_block_color5_r(base_color, inten_table, low_selector, r);

			// Constant alpha block
			// Select table 13, use selector 4 (0), set multiplier to 1 and base color r
			pDst_block->m_base = r;
			pDst_block->m_table = 13;
			pDst_block->m_multiplier = 1;

			// selectors are all 4's
			static const uint8_t s_etc2_eac_r11_sel4[6] = { 0x92, 0x49, 0x24, 0x92, 0x49, 0x24 };
			memcpy(pDst_block->m_selectors, s_etc2_eac_r11_sel4, sizeof(s_etc2_eac_r11_sel4));

			return;
		}

		uint32_t selector_range_table = 0;
		for (selector_range_table = 0; selector_range_table < NUM_ETC2_EAC_SELECTOR_RANGES; selector_range_table++)
			if ((low_selector == s_etc2_eac_selector_ranges[selector_range_table].m_low) && (high_selector == s_etc2_eac_selector_ranges[selector_range_table].m_high))
				break;
		if (selector_range_table >= NUM_ETC2_EAC_SELECTOR_RANGES)
			selector_range_table = 0;

		const etc1_g_to_eac_conversion* pTable_entry = &s_etc1_g_to_etc2_r11[base_color.r + inten_table * 32][selector_range_table];

		pDst_block->m_base = pTable_entry->m_base;
		pDst_block->m_table = pTable_entry->m_table_mul >> 4;
		pDst_block->m_multiplier = pTable_entry->m_table_mul & 15;

		uint64_t selector_bits = 0;

		for (uint32_t y = 0; y < 4; y++)
		{
			for (uint32_t x = 0; x < 4; x++)
			{
				uint32_t s = pSelector->get_selector(x, y);

				uint32_t ds = (pTable_entry->m_trans >> (s * 3)) & 7;

				const uint32_t dst_ofs = 45 - (y + x * 4) * 3;
				selector_bits |= (static_cast<uint64_t>(ds) << dst_ofs);
			}
		}

		pDst_block->set_selector_bits(selector_bits);
	}
#endif // BASISD_SUPPORT_ETC2_EAC_RG11

// ASTC
	struct etc1_to_astc_solution
	{
		uint8_t m_lo;
		uint8_t m_hi;
		uint16_t m_err;
	};

#if BASISD_SUPPORT_ASTC
	static dxt_selector_range g_etc1_to_astc_selector_ranges[] =
	{
		{ 0, 3 },

		{ 1, 3 },
		{ 0, 2 },

		{ 1, 2 },

		{ 2, 3 },
		{ 0, 1 },
	};

	const uint32_t NUM_ETC1_TO_ASTC_SELECTOR_RANGES = sizeof(g_etc1_to_astc_selector_ranges) / sizeof(g_etc1_to_astc_selector_ranges[0]);

	static uint32_t g_etc1_to_astc_selector_range_index[4][4];

	const uint32_t NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS = 10;
	static const uint8_t g_etc1_to_astc_selector_mappings[NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS][4] =
	{
		{ 0, 0, 1, 1 },
		{ 0, 0, 1, 2 },
		{ 0, 0, 1, 3 },
		{ 0, 0, 2, 3 },
		{ 0, 1, 1, 1 },
		{ 0, 1, 2, 2 },
		{ 0, 1, 2, 3 },
		{ 0, 2, 3, 3 },
		{ 1, 2, 2, 2 },
		{ 1, 2, 3, 3 },
	};

	static const etc1_to_astc_solution g_etc1_to_astc[32 * 8 * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS * NUM_ETC1_TO_ASTC_SELECTOR_RANGES] = {
#include "basisu_transcoder_tables_astc.inc"
	};

	// The best selector mapping to use given a base base+inten table and used selector range for converting grayscale data.
	static uint8_t g_etc1_to_astc_best_grayscale_mapping[32][8][NUM_ETC1_TO_ASTC_SELECTOR_RANGES];
	
#if BASISD_SUPPORT_ASTC_HIGHER_OPAQUE_QUALITY
	static const etc1_to_astc_solution g_etc1_to_astc_0_255[32 * 8 * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS * NUM_ETC1_TO_ASTC_SELECTOR_RANGES] = {
#include "basisu_transcoder_tables_astc_0_255.inc"
	};
	static uint8_t g_etc1_to_astc_best_grayscale_mapping_0_255[32][8][NUM_ETC1_TO_ASTC_SELECTOR_RANGES];
#endif

	static uint32_t g_ise_to_unquant[48];

#if BASISD_WRITE_NEW_ASTC_TABLES
	static void create_etc1_to_astc_conversion_table_0_47()
	{
		FILE* pFile = nullptr;
		fopen_s(&pFile, "basisu_transcoder_tables_astc.inc", "w");

		uint32_t n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1_TO_ASTC_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1_to_astc_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1_to_astc_selector_ranges[sr].m_high;

					uint32_t mapping_best_low[NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];
					uint32_t mapping_best_high[NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];
					uint64_t mapping_best_err[NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];
					uint64_t highest_best_err = 0;

					for (uint32_t m = 0; m < NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS; m++)
					{
						uint32_t best_lo = 0;
						uint32_t best_hi = 0;
						uint64_t best_err = UINT64_MAX;

						for (uint32_t hi = 0; hi <= 47; hi++)
						{
							for (uint32_t lo = 0; lo <= 47; lo++)
							{
								uint32_t colors[4];

								for (uint32_t s = 0; s < 4; s++)
								{
									uint32_t s_scaled = s | (s << 2) | (s << 4);
									if (s_scaled > 32)
										s_scaled++;

									uint32_t c0 = g_ise_to_unquant[lo] | (g_ise_to_unquant[lo] << 8);
									uint32_t c1 = g_ise_to_unquant[hi] | (g_ise_to_unquant[hi] << 8);
									colors[s] = ((c0 * (64 - s_scaled) + c1 * s_scaled + 32) / 64) >> 8;
								}

								uint64_t total_err = 0;

								for (uint32_t s = low_selector; s <= high_selector; s++)
								{
									int err = block_colors[s].g - colors[g_etc1_to_astc_selector_mappings[m][s]];

									int err_scale = 1;
									// Special case when the intensity table is 7, low_selector is 0, and high_selector is 3. In this extreme case, it's likely the encoder is trying to strongly favor 
									// the low/high selectors which are clamping to either 0 or 255.
									if (((inten == 7) && (low_selector == 0) && (high_selector == 3)) && ((s == 0) || (s == 3)))
										err_scale = 8;

									total_err += (err * err) * err_scale;
								}

								if (total_err < best_err)
								{
									best_err = total_err;
									best_lo = lo;
									best_hi = hi;
								}
							}
						}

						mapping_best_low[m] = best_lo;
						mapping_best_high[m] = best_hi;
						mapping_best_err[m] = best_err;
						highest_best_err = basisu::maximum(highest_best_err, best_err);
												
					} // m

					for (uint32_t m = 0; m < NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS; m++)
					{
						uint64_t err = mapping_best_err[m];

						err = basisu::minimum<uint64_t>(err, 0xFFFF);

						fprintf(pFile, "{%u,%u,%u},", mapping_best_low[m], mapping_best_high[m], (uint32_t)err);

						n++;
						if ((n & 31) == 31)
							fprintf(pFile, "\n");
					} // m

				} // sr
			} // g
		} // inten

		fclose(pFile);
	}

	static void create_etc1_to_astc_conversion_table_0_255()
	{
		FILE* pFile = nullptr;
		fopen_s(&pFile, "basisu_transcoder_tables_astc_0_255.inc", "w");

		uint32_t n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1_TO_ASTC_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1_to_astc_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1_to_astc_selector_ranges[sr].m_high;

					uint32_t mapping_best_low[NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];
					uint32_t mapping_best_high[NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];
					uint64_t mapping_best_err[NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];
					uint64_t highest_best_err = 0;

					for (uint32_t m = 0; m < NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS; m++)
					{
						uint32_t best_lo = 0;
						uint32_t best_hi = 0;
						uint64_t best_err = UINT64_MAX;

						for (uint32_t hi = 0; hi <= 255; hi++)
						{
							for (uint32_t lo = 0; lo <= 255; lo++)
							{
								uint32_t colors[4];

								for (uint32_t s = 0; s < 4; s++)
								{
									uint32_t s_scaled = s | (s << 2) | (s << 4);
									if (s_scaled > 32)
										s_scaled++;

									uint32_t c0 = lo | (lo << 8);
									uint32_t c1 = hi | (hi << 8);
									colors[s] = ((c0 * (64 - s_scaled) + c1 * s_scaled + 32) / 64) >> 8;
								}

								uint64_t total_err = 0;

								for (uint32_t s = low_selector; s <= high_selector; s++)
								{
									int err = block_colors[s].g - colors[g_etc1_to_astc_selector_mappings[m][s]];

									// Special case when the intensity table is 7, low_selector is 0, and high_selector is 3. In this extreme case, it's likely the encoder is trying to strongly favor 
									// the low/high selectors which are clamping to either 0 or 255.
									int err_scale = 1;
									if (((inten == 7) && (low_selector == 0) && (high_selector == 3)) && ((s == 0) || (s == 3)))
										err_scale = 8;

									total_err += (err * err) * err_scale;
								}

								if (total_err < best_err)
								{
									best_err = total_err;
									best_lo = lo;
									best_hi = hi;
								}
							}
						}

						mapping_best_low[m] = best_lo;
						mapping_best_high[m] = best_hi;
						mapping_best_err[m] = best_err;
						highest_best_err = basisu::maximum(highest_best_err, best_err);
					} // m

					for (uint32_t m = 0; m < NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS; m++)
					{
						uint64_t err = mapping_best_err[m];

						err = basisu::minimum<uint64_t>(err, 0xFFFF);
						
						fprintf(pFile, "{%u,%u,%u},", mapping_best_low[m], mapping_best_high[m], (uint32_t)err);
						
						n++;
						if ((n & 31) == 31)
							fprintf(pFile, "\n");
					} // m

				} // sr
			} // g
		} // inten

		fclose(pFile);
	}
#endif

#endif

#if BASISD_SUPPORT_UASTC || BASISD_SUPPORT_ASTC
	// Table encodes 5 trits to 8 output bits. 3^5 entries.
	// Inverse of the trit bit manipulation process in https://www.khronos.org/registry/DataFormat/specs/1.2/dataformat.1.2.html#astc-integer-sequence-encoding
	static const uint8_t g_astc_trit_encode[243] = { 0, 1, 2, 4, 5, 6, 8, 9, 10, 16, 17, 18, 20, 21, 22, 24, 25, 26, 3, 7, 11, 19, 23, 27, 12, 13, 14, 32, 33, 34, 36, 37, 38, 40, 41, 42, 48, 49, 50, 52, 53, 54, 56, 57, 58, 35, 39,
		43, 51, 55, 59, 44, 45, 46, 64, 65, 66, 68, 69, 70, 72, 73, 74, 80, 81, 82, 84, 85, 86, 88, 89, 90, 67, 71, 75, 83, 87, 91, 76, 77, 78, 128, 129, 130, 132, 133, 134, 136, 137, 138, 144, 145, 146, 148, 149, 150, 152, 153, 154,
		131, 135, 139, 147, 151, 155, 140, 141, 142, 160, 161, 162, 164, 165, 166, 168, 169, 170, 176, 177, 178, 180, 181, 182, 184, 185, 186, 163, 167, 171, 179, 183, 187, 172, 173, 174, 192, 193, 194, 196, 197, 198, 200, 201, 202,
		208, 209, 210, 212, 213, 214, 216, 217, 218, 195, 199, 203, 211, 215, 219, 204, 205, 206, 96, 97, 98, 100, 101, 102, 104, 105, 106, 112, 113, 114, 116, 117, 118, 120, 121, 122, 99, 103, 107, 115, 119, 123, 108, 109, 110, 224,
		225, 226, 228, 229, 230, 232, 233, 234, 240, 241, 242, 244, 245, 246, 248, 249, 250, 227, 231, 235, 243, 247, 251, 236, 237, 238, 28, 29, 30, 60, 61, 62, 92, 93, 94, 156, 157, 158, 188, 189, 190, 220, 221, 222, 31, 63, 95, 159,
		191, 223, 124, 125, 126 };

	// Extracts bits [low,high]
	static inline uint32_t astc_extract_bits(uint32_t bits, int low, int high)
	{
		return (bits >> low) & ((1 << (high - low + 1)) - 1);
	}

	// Writes bits to output in an endian safe way
	static inline void astc_set_bits(uint32_t* pOutput, int& bit_pos, uint32_t value, uint32_t total_bits)
	{
		uint8_t* pBytes = reinterpret_cast<uint8_t*>(pOutput);

		while (total_bits)
		{
			const uint32_t bits_to_write = basisu::minimum<int>(total_bits, 8 - (bit_pos & 7));

			pBytes[bit_pos >> 3] |= static_cast<uint8_t>(value << (bit_pos & 7));

			bit_pos += bits_to_write;
			total_bits -= bits_to_write;
			value >>= bits_to_write;
		}
	}

	// Encodes 5 values to output, usable for any range that uses trits and bits
	static void astc_encode_trits(uint32_t* pOutput, const uint8_t* pValues, int& bit_pos, int n)
	{
		// First extract the trits and the bits from the 5 input values
		int trits = 0, bits[5];
		const uint32_t bit_mask = (1 << n) - 1;
		for (int i = 0; i < 5; i++)
		{
			static const int s_muls[5] = { 1, 3, 9, 27, 81 };

			const int t = pValues[i] >> n;

			trits += t * s_muls[i];
			bits[i] = pValues[i] & bit_mask;
		}

		// Encode the trits, by inverting the bit manipulations done by the decoder, converting 5 trits into 8-bits.
		// See https://www.khronos.org/registry/DataFormat/specs/1.2/dataformat.1.2.html#astc-integer-sequence-encoding

		assert(trits < 243);
		const int T = g_astc_trit_encode[trits];

		// Now interleave the 8 encoded trit bits with the bits to form the encoded output. See table 94.
		astc_set_bits(pOutput, bit_pos, bits[0] | (astc_extract_bits(T, 0, 1) << n) | (bits[1] << (2 + n)), n * 2 + 2);

		astc_set_bits(pOutput, bit_pos, astc_extract_bits(T, 2, 3) | (bits[2] << 2) | (astc_extract_bits(T, 4, 4) << (2 + n)) | (bits[3] << (3 + n)) | (astc_extract_bits(T, 5, 6) << (3 + n * 2)) |
			(bits[4] << (5 + n * 2)) | (astc_extract_bits(T, 7, 7) << (5 + n * 3)), n * 3 + 6);
	}
#endif // #if BASISD_SUPPORT_UASTC || BASISD_SUPPORT_ASTC

#if BASISD_SUPPORT_ASTC
	struct astc_block_params
	{
		// 2 groups of 5, but only a max of 8 are used (RRGGBBAA00)
		uint8_t m_endpoints[10]; 
		uint8_t m_weights[32];
	};
	
	// Packs a single format ASTC block using Color Endpoint Mode 12 (LDR RGBA direct), endpoint BISE range 13, 2-bit weights (range 2). 
	// We're always going to output blocks containing alpha, even if the input doesn't have alpha, for simplicity.
	// Each block always has 4x4 weights, uses range 13 BISE encoding on the endpoints (0-47), and each weight ranges from 0-3. This encoding should be roughly equal in quality vs. BC1 for color.
	// 8 total endpoints, stored as RGBA LH LH LH LH order, each ranging from 0-47. 
	// Note the input [0,47] endpoint values are not linear - they are encoded as outlined in the ASTC spec:
	// https://www.khronos.org/registry/DataFormat/specs/1.2/dataformat.1.2.html#astc-endpoint-unquantization
	// 32 total weights, stored as 16 CA CA, each ranging from 0-3.
	static void astc_pack_block_cem_12_weight_range2(uint32_t *pOutput, const astc_block_params* pBlock)
	{
		uint8_t* pBytes = reinterpret_cast<uint8_t*>(pOutput);

		// Write constant block mode, color component selector, number of partitions, color endpoint mode
		// https://www.khronos.org/registry/DataFormat/specs/1.2/dataformat.1.2.html#_block_mode
		pBytes[0] = 0x42; pBytes[1] = 0x84; pBytes[2] = 0x01; pBytes[3] = 0x00;
		pBytes[4] = 0x00; pBytes[5] = 0x00; pBytes[6] = 0x00; pBytes[7] = 0xc0;

		pOutput[2] = 0;
		pOutput[3] = 0;

		// Pack 8 endpoints (each ranging between [0,47]) using BISE starting at bit 17
		int bit_pos = 17;
		astc_encode_trits(pOutput, pBlock->m_endpoints, bit_pos, 4);
		astc_encode_trits(pOutput, pBlock->m_endpoints + 5, bit_pos, 4);

		// Pack 32 2-bit weights, which are stored from the top down into the block in opposite bit order.
				
		for (uint32_t i = 0; i < 32; i++)
		{
			static const uint8_t s_reverse_bits[4] = { 0, 2, 1, 3 };
			const uint32_t ofs = 126 - (i * 2);
			pBytes[ofs >> 3] |= (s_reverse_bits[pBlock->m_weights[i]] << (ofs & 7));
		}
	}

	// CEM mode 12 (LDR RGBA Direct), 8-bit endpoints, 1-bit weights 
	// This ASTC mode is basically block truncation coding (BTC) using 1-bit weights and 8-bit/component endpoints - very convenient.
	static void astc_pack_block_cem_12_weight_range0(uint32_t* pOutput, const astc_block_params* pBlock)
	{
		uint8_t* pBytes = reinterpret_cast<uint8_t*>(pOutput);

		// Write constant block mode, color component selector, number of partitions, color endpoint mode
		// https://www.khronos.org/registry/DataFormat/specs/1.2/dataformat.1.2.html#_block_mode
		pBytes[0] = 0x41; pBytes[1] = 0x84; pBytes[2] = 0x01; pBytes[3] = 0x00;
		pOutput[1] = 0;
		pBytes[8] = 0x00; pBytes[9] = 0x00; pBytes[10] = 0x00; pBytes[11] = 0xc0;
		pOutput[3] = 0;

		// Pack 8 endpoints (each ranging between [0,255]) as 8-bits starting at bit 17
		int bit_pos = 17;
		for (uint32_t i = 0; i < 8; i++)
			astc_set_bits(pOutput, bit_pos, pBlock->m_endpoints[i], 8);

		// Pack 32 1-bit weights, which are stored from the top down into the block in opposite bit order.
		for (uint32_t i = 0; i < 32; i++)
		{
			const uint32_t ofs = 127 - i;
			pBytes[ofs >> 3] |= (pBlock->m_weights[i] << (ofs & 7));
		}
	}

#if BASISD_SUPPORT_ASTC_HIGHER_OPAQUE_QUALITY
	// Optional 8-bit endpoint packing functions.

	// CEM mode 4 (LDR Luminance+Alpha Direct), 8-bit endpoints, 2 bit weights
	static void astc_pack_block_cem_4_weight_range2(uint32_t* pOutput, const astc_block_params* pBlock)
	{
		uint8_t* pBytes = reinterpret_cast<uint8_t*>(pOutput);

		// Write constant block mode, color component selector, number of partitions, color endpoint mode
		// https://www.khronos.org/registry/DataFormat/specs/1.2/dataformat.1.2.html#_block_mode
		pBytes[0] = 0x42; pBytes[1] = 0x84; pBytes[2] = 0x00; pBytes[3] = 0x00;
		pBytes[4] = 0x00; pBytes[5] = 0x00; pBytes[6] = 0x00; pBytes[7] = 0xc0;
		
		pOutput[2] = 0;
		pOutput[3] = 0;

		// Pack 4 endpoints (each ranging between [0,255]) as 8-bits starting at bit 17
		int bit_pos = 17;
		for (uint32_t i = 0; i < 4; i++)
			astc_set_bits(pOutput, bit_pos, pBlock->m_endpoints[i], 8);

		// Pack 32 2-bit weights, which are stored from the top down into the block in opposite bit order.
		for (uint32_t i = 0; i < 32; i++)
		{
			static const uint8_t s_reverse_bits[4] = { 0, 2, 1, 3 };
			const uint32_t ofs = 126 - (i * 2);
			pBytes[ofs >> 3] |= (s_reverse_bits[pBlock->m_weights[i]] << (ofs & 7));
		}
	}

	// CEM mode 8 (LDR RGB Direct), 8-bit endpoints, 2 bit weights
	static void astc_pack_block_cem_8_weight_range2(uint32_t* pOutput, const astc_block_params* pBlock)
	{
		uint8_t* pBytes = reinterpret_cast<uint8_t*>(pOutput);

		// Write constant block mode, color component selector, number of partitions, color endpoint mode
		// https://www.khronos.org/registry/DataFormat/specs/1.2/dataformat.1.2.html#_block_mode
		pBytes[0] = 0x42; pBytes[1] = 0x00; pBytes[2] = 0x01; pBytes[3] = 0x00;
		
		pOutput[1] = 0;
		pOutput[2] = 0;
		pOutput[3] = 0;

		// Pack 6 endpoints (each ranging between [0,255]) as 8-bits starting at bit 17
		int bit_pos = 17;
		for (uint32_t i = 0; i < 6; i++)
			astc_set_bits(pOutput, bit_pos, pBlock->m_endpoints[i], 8);

		// Pack 16 2-bit weights, which are stored from the top down into the block in opposite bit order.
		for (uint32_t i = 0; i < 16; i++)
		{
			static const uint8_t s_reverse_bits[4] = { 0, 2, 1, 3 };
			const uint32_t ofs = 126 - (i * 2);
			pBytes[ofs >> 3] |= (s_reverse_bits[pBlock->m_weights[i]] << (ofs & 7));
		}
	}
#endif

	// Optimal quantized [0,47] entry to use given [0,255] input
	static uint8_t g_astc_single_color_encoding_0[256];

	// Optimal quantized [0,47] low/high values given [0,255] input assuming a selector of 1
	static struct
	{
		uint8_t m_lo, m_hi;
	} g_astc_single_color_encoding_1[256];
		
	static void transcoder_init_astc()
	{
		for (uint32_t base_color = 0; base_color < 32; base_color++)
		{
			for (uint32_t inten_table = 0; inten_table < 8; inten_table++)
			{
				for (uint32_t range_index = 0; range_index < NUM_ETC1_TO_ASTC_SELECTOR_RANGES; range_index++)
				{
					const etc1_to_astc_solution* pTable_g = &g_etc1_to_astc[(inten_table * 32 + base_color) * (NUM_ETC1_TO_ASTC_SELECTOR_RANGES * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS) + range_index * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];

					uint32_t best_mapping = 0;
					uint32_t best_err = UINT32_MAX;
					for (uint32_t mapping_index = 0; mapping_index < NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS; mapping_index++)
					{
						if (pTable_g[mapping_index].m_err < best_err)
						{
							best_err = pTable_g[mapping_index].m_err;
							best_mapping = mapping_index;
						}
					}

					g_etc1_to_astc_best_grayscale_mapping[base_color][inten_table][range_index] = static_cast<uint8_t>(best_mapping);
				}
			}
		}

#if BASISD_SUPPORT_ASTC_HIGHER_OPAQUE_QUALITY
		for (uint32_t base_color = 0; base_color < 32; base_color++)
		{
			for (uint32_t inten_table = 0; inten_table < 8; inten_table++)
			{
				for (uint32_t range_index = 0; range_index < NUM_ETC1_TO_ASTC_SELECTOR_RANGES; range_index++)
				{
					const etc1_to_astc_solution* pTable_g = &g_etc1_to_astc_0_255[(inten_table * 32 + base_color) * (NUM_ETC1_TO_ASTC_SELECTOR_RANGES * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS) + range_index * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];

					uint32_t best_mapping = 0;
					uint32_t best_err = UINT32_MAX;
					for (uint32_t mapping_index = 0; mapping_index < NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS; mapping_index++)
					{
						if (pTable_g[mapping_index].m_err < best_err)
						{
							best_err = pTable_g[mapping_index].m_err;
							best_mapping = mapping_index;
						}
					}

					g_etc1_to_astc_best_grayscale_mapping_0_255[base_color][inten_table][range_index] = static_cast<uint8_t>(best_mapping);
				}
			}
		}
#endif

		for (uint32_t i = 0; i < NUM_ETC1_TO_ASTC_SELECTOR_RANGES; i++)
		{
			uint32_t l = g_etc1_to_astc_selector_ranges[i].m_low;
			uint32_t h = g_etc1_to_astc_selector_ranges[i].m_high;
			g_etc1_to_astc_selector_range_index[l][h] = i;
		}

		// Endpoint dequantization, see:
		// https://www.khronos.org/registry/DataFormat/specs/1.2/dataformat.1.2.html#astc-endpoint-unquantization
		for (uint32_t trit = 0; trit < 3; trit++)
		{
			for (uint32_t bit = 0; bit < 16; bit++)
			{
				const uint32_t A = (bit & 1) ? 511 : 0;
				const uint32_t B = (bit >> 1) | ((bit >> 1) << 6);
				const uint32_t C = 22;
				const uint32_t D = trit;

				uint32_t unq = D * C + B;
				unq = unq ^ A;
				unq = (A & 0x80) | (unq >> 2);

				g_ise_to_unquant[bit | (trit << 4)] = unq;
			}
		}
				
		// Compute table used for optimal single color encoding.
		for (int i = 0; i < 256; i++)
		{
			int lowest_e = INT_MAX;

			for (int lo = 0; lo < 48; lo++)
			{
				for (int hi = 0; hi < 48; hi++)
				{
					const int lo_v = g_ise_to_unquant[lo];
					const int hi_v = g_ise_to_unquant[hi];

					int l = lo_v | (lo_v << 8);
					int h = hi_v | (hi_v << 8);
										
					int v = ((l * (64 - 21) + (h * 21) + 32) / 64) >> 8;
					
					int e = abs(v - i);

					if (e < lowest_e)
					{
						g_astc_single_color_encoding_1[i].m_hi = static_cast<uint8_t>(hi);
						g_astc_single_color_encoding_1[i].m_lo = static_cast<uint8_t>(lo);

						lowest_e = e;
					}

				} // hi
			} // lo
		}

		for (int i = 0; i < 256; i++)
		{
			int lowest_e = INT_MAX;

			for (int lo = 0; lo < 48; lo++)
			{
				const int lo_v = g_ise_to_unquant[lo];
				
				int e = abs(lo_v - i);

				if (e < lowest_e)
				{
					g_astc_single_color_encoding_0[i] = static_cast<uint8_t>(lo);

					lowest_e = e;
				}
			} // lo
		}
	}

	// Converts opaque or color+alpha ETC1S block to ASTC 4x4.
	// This function tries to use the best ASTC mode given the block's actual contents.
	static void convert_etc1s_to_astc_4x4(void* pDst_block, const endpoint* pEndpoints, const selector* pSelector, 
		bool transcode_alpha, const endpoint *pEndpoint_codebook, const selector *pSelector_codebook)
	{
		astc_block_params blk;

		blk.m_endpoints[8] = 0;
		blk.m_endpoints[9] = 0;

		int constant_alpha_val = 255;
		int num_unique_alpha_selectors = 1;

		if (transcode_alpha)
		{
			const selector& alpha_selectors = pSelector_codebook[((uint16_t*)pDst_block)[1]];

			num_unique_alpha_selectors = alpha_selectors.m_num_unique_selectors;

			if (num_unique_alpha_selectors == 1)
			{
				const endpoint& alpha_endpoint = pEndpoint_codebook[((uint16_t*)pDst_block)[0]];

				const color32& alpha_base_color = alpha_endpoint.m_color5;
				const uint32_t alpha_inten_table = alpha_endpoint.m_inten5;

				int alpha_block_colors[4];
				decoder_etc_block::get_block_colors5_g(alpha_block_colors, alpha_base_color, alpha_inten_table);

				constant_alpha_val = alpha_block_colors[alpha_selectors.m_lo_selector];
			}
		}

		const color32& base_color = pEndpoints->m_color5;
		const uint32_t inten_table = pEndpoints->m_inten5;

		const uint32_t low_selector = pSelector->m_lo_selector;
		const uint32_t high_selector = pSelector->m_hi_selector;

		// Handle solid color or BTC blocks, which can always be encoded from ETC1S to ASTC losslessly.
		if ((pSelector->m_num_unique_selectors == 1) && (num_unique_alpha_selectors == 1))
		{
			// Both color and alpha are constant, write a solid color block and exit.
			// See https://www.khronos.org/registry/DataFormat/specs/1.2/dataformat.1.2.html#astc-void-extent-blocks
			uint32_t r, g, b;
			decoder_etc_block::get_block_color5(base_color, inten_table, low_selector, r, g, b);
						
			uint32_t* pOutput = static_cast<uint32_t*>(pDst_block);
			uint8_t* pBytes = reinterpret_cast<uint8_t*>(pDst_block);

			pBytes[0] = 0xfc; pBytes[1] = 0xfd; pBytes[2] = 0xff; pBytes[3] = 0xff;

			pOutput[1] = 0xffffffff;
			pOutput[2] = 0;
			pOutput[3] = 0;

			int bit_pos = 64;
			astc_set_bits(pOutput, bit_pos, r | (r << 8), 16);
			astc_set_bits(pOutput, bit_pos, g | (g << 8), 16);
			astc_set_bits(pOutput, bit_pos, b | (b << 8), 16);
			astc_set_bits(pOutput, bit_pos, constant_alpha_val | (constant_alpha_val << 8), 16);

			return;
		}
		else if ((pSelector->m_num_unique_selectors <= 2) && (num_unique_alpha_selectors <= 2))
		{
			// Both color and alpha use <= 2 unique selectors each. 
			// Use block truncation coding, which is lossless with ASTC (8-bit endpoints, 1-bit weights).
			color32 block_colors[4];
			decoder_etc_block::get_block_colors5(block_colors, base_color, inten_table);

			blk.m_endpoints[0] = block_colors[low_selector].r;
			blk.m_endpoints[2] = block_colors[low_selector].g;
			blk.m_endpoints[4] = block_colors[low_selector].b;

			blk.m_endpoints[1] = block_colors[high_selector].r;
			blk.m_endpoints[3] = block_colors[high_selector].g;
			blk.m_endpoints[5] = block_colors[high_selector].b;

			int s0 = blk.m_endpoints[0] + blk.m_endpoints[2] + blk.m_endpoints[4];
			int s1 = blk.m_endpoints[1] + blk.m_endpoints[3] + blk.m_endpoints[5];
			bool invert = false;
			if (s1 < s0)
			{
				std::swap(blk.m_endpoints[0], blk.m_endpoints[1]);
				std::swap(blk.m_endpoints[2], blk.m_endpoints[3]);
				std::swap(blk.m_endpoints[4], blk.m_endpoints[5]);
				invert = true;
			}

			if (transcode_alpha)
			{
				const endpoint& alpha_endpoint = pEndpoint_codebook[((uint16_t*)pDst_block)[0]];
				const selector& alpha_selectors = pSelector_codebook[((uint16_t*)pDst_block)[1]];

				const color32& alpha_base_color = alpha_endpoint.m_color5;
				const uint32_t alpha_inten_table = alpha_endpoint.m_inten5;

				const uint32_t alpha_low_selector = alpha_selectors.m_lo_selector;
				const uint32_t alpha_high_selector = alpha_selectors.m_hi_selector;

				int alpha_block_colors[4];
				decoder_etc_block::get_block_colors5_g(alpha_block_colors, alpha_base_color, alpha_inten_table);

				blk.m_endpoints[6] = static_cast<uint8_t>(alpha_block_colors[alpha_low_selector]);
				blk.m_endpoints[7] = static_cast<uint8_t>(alpha_block_colors[alpha_high_selector]);

				for (uint32_t y = 0; y < 4; y++)
				{
					for (uint32_t x = 0; x < 4; x++)
					{
						uint32_t s = alpha_selectors.get_selector(x, y);
						s = (s == alpha_high_selector) ? 1 : 0;
												
						blk.m_weights[(x + y * 4) * 2 + 1] = static_cast<uint8_t>(s);
					} // x
				} // y
			}
			else
			{
				blk.m_endpoints[6] = 255;
				blk.m_endpoints[7] = 255;

				for (uint32_t i = 0; i < 16; i++)
					blk.m_weights[i * 2 + 1] = 0;
			}

			for (uint32_t y = 0; y < 4; y++)
			{
				for (uint32_t x = 0; x < 4; x++)
				{
					uint32_t s = pSelector->get_selector(x, y);

					s = (s == high_selector) ? 1 : 0;

					if (invert)
						s = 1 - s;

					blk.m_weights[(x + y * 4) * 2] = static_cast<uint8_t>(s);
				} // x
			} // y

			astc_pack_block_cem_12_weight_range0(reinterpret_cast<uint32_t*>(pDst_block), &blk);

			return;
		}
				
		// Either alpha and/or color use > 2 unique selectors each, so we must do something more complex.
				
#if BASISD_SUPPORT_ASTC_HIGHER_OPAQUE_QUALITY
		// The optional higher quality modes use 8-bits endpoints vs. [0,47] endpoints.
		
		// If the block's base color is grayscale, all pixels are grayscale, so encode the block as Luminance+Alpha.
		if ((base_color.r == base_color.g) && (base_color.r == base_color.b))
		{
			if (transcode_alpha)
			{
				const endpoint& alpha_endpoint = pEndpoint_codebook[((uint16_t*)pDst_block)[0]];
				const selector& alpha_selectors = pSelector_codebook[((uint16_t*)pDst_block)[1]];

				const color32& alpha_base_color = alpha_endpoint.m_color5;
				const uint32_t alpha_inten_table = alpha_endpoint.m_inten5;

				const uint32_t alpha_low_selector = alpha_selectors.m_lo_selector;
				const uint32_t alpha_high_selector = alpha_selectors.m_hi_selector;

				if (num_unique_alpha_selectors <= 2)
				{
					// Simple alpha block with only 1 or 2 unique values, so use BTC. This is lossless.
					int alpha_block_colors[4];
					decoder_etc_block::get_block_colors5_g(alpha_block_colors, alpha_base_color, alpha_inten_table);

					blk.m_endpoints[2] = static_cast<uint8_t>(alpha_block_colors[alpha_low_selector]);
					blk.m_endpoints[3] = static_cast<uint8_t>(alpha_block_colors[alpha_high_selector]);

					for (uint32_t i = 0; i < 16; i++)
					{
						uint32_t s = alpha_selectors.get_selector(i & 3, i >> 2);
						blk.m_weights[i * 2 + 1] = (s == alpha_high_selector) ? 3 : 0;
					}
				}
				else
				{
					// Convert ETC1S alpha
					const uint32_t alpha_selector_range_table = g_etc1_to_astc_selector_range_index[alpha_low_selector][alpha_high_selector];
										
					//[32][8][RANGES][MAPPING]
					const etc1_to_astc_solution* pTable_g = &g_etc1_to_astc_0_255[(alpha_inten_table * 32 + alpha_base_color.g) * (NUM_ETC1_TO_ASTC_SELECTOR_RANGES * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS) + alpha_selector_range_table * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];

					const uint32_t best_mapping = g_etc1_to_astc_best_grayscale_mapping_0_255[alpha_base_color.g][alpha_inten_table][alpha_selector_range_table];

					blk.m_endpoints[2] = pTable_g[best_mapping].m_lo;
					blk.m_endpoints[3] = pTable_g[best_mapping].m_hi;
										
					const uint8_t* pSelectors_xlat = &g_etc1_to_astc_selector_mappings[best_mapping][0];

					for (uint32_t y = 0; y < 4; y++)
					{
						for (uint32_t x = 0; x < 4; x++)
						{
							uint32_t s = alpha_selectors.get_selector(x, y);
							uint32_t as = pSelectors_xlat[s];

							blk.m_weights[(x + y * 4) * 2 + 1] = static_cast<uint8_t>(as);
						} // x
					} // y
				}
			}
			else
			{
				// No alpha slice - set output alpha to all 255's
				blk.m_endpoints[2] = 255;
				blk.m_endpoints[3] = 255;

				for (uint32_t i = 0; i < 16; i++)
					blk.m_weights[i * 2 + 1] = 0;
			}

			if (pSelector->m_num_unique_selectors <= 2)
			{
				// Simple color block with only 1 or 2 unique values, so use BTC. This is lossless.
				int block_colors[4];
				decoder_etc_block::get_block_colors5_g(block_colors, base_color, inten_table);

				blk.m_endpoints[0] = static_cast<uint8_t>(block_colors[low_selector]);
				blk.m_endpoints[1] = static_cast<uint8_t>(block_colors[high_selector]);

				for (uint32_t i = 0; i < 16; i++)
				{
					uint32_t s = pSelector->get_selector(i & 3, i >> 2);
					blk.m_weights[i * 2] = (s == high_selector) ? 3 : 0;
				}
			}
			else
			{
				// Convert ETC1S alpha
				const uint32_t selector_range_table = g_etc1_to_astc_selector_range_index[low_selector][high_selector];
								
				//[32][8][RANGES][MAPPING]
				const etc1_to_astc_solution* pTable_g = &g_etc1_to_astc_0_255[(inten_table * 32 + base_color.g) * (NUM_ETC1_TO_ASTC_SELECTOR_RANGES * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];
								
				const uint32_t best_mapping = g_etc1_to_astc_best_grayscale_mapping_0_255[base_color.g][inten_table][selector_range_table];

				blk.m_endpoints[0] = pTable_g[best_mapping].m_lo;
				blk.m_endpoints[1] = pTable_g[best_mapping].m_hi;

				const uint8_t* pSelectors_xlat = &g_etc1_to_astc_selector_mappings[best_mapping][0];

				for (uint32_t y = 0; y < 4; y++)
				{
					for (uint32_t x = 0; x < 4; x++)
					{
						uint32_t s = pSelector->get_selector(x, y);
						uint32_t as = pSelectors_xlat[s];

						blk.m_weights[(x + y * 4) * 2] = static_cast<uint8_t>(as);
					} // x
				} // y
			}

			astc_pack_block_cem_4_weight_range2(reinterpret_cast<uint32_t*>(pDst_block), &blk);
			return;
		}

		// The block isn't grayscale and it uses > 2 unique selectors for opaque and/or alpha.
		// Check for fully opaque blocks, if so use 8-bit endpoints for slightly higher opaque quality (higher than BC1, but lower than BC7 mode 6 opaque).
		if ((num_unique_alpha_selectors == 1) && (constant_alpha_val == 255))
		{
			// Convert ETC1S color
			const uint32_t selector_range_table = g_etc1_to_astc_selector_range_index[low_selector][high_selector];

			//[32][8][RANGES][MAPPING]
			const etc1_to_astc_solution* pTable_r = &g_etc1_to_astc_0_255[(inten_table * 32 + base_color.r) * (NUM_ETC1_TO_ASTC_SELECTOR_RANGES * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];
			const etc1_to_astc_solution* pTable_g = &g_etc1_to_astc_0_255[(inten_table * 32 + base_color.g) * (NUM_ETC1_TO_ASTC_SELECTOR_RANGES * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];
			const etc1_to_astc_solution* pTable_b = &g_etc1_to_astc_0_255[(inten_table * 32 + base_color.b) * (NUM_ETC1_TO_ASTC_SELECTOR_RANGES * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];

			uint32_t best_err = UINT_MAX;
			uint32_t best_mapping = 0;

			assert(NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS == 10);
#define DO_ITER(m) { uint32_t total_err = pTable_r[m].m_err + pTable_g[m].m_err + pTable_b[m].m_err; if (total_err < best_err) { best_err = total_err; best_mapping = m; } }
			DO_ITER(0); DO_ITER(1); DO_ITER(2); DO_ITER(3); DO_ITER(4);
			DO_ITER(5); DO_ITER(6); DO_ITER(7); DO_ITER(8); DO_ITER(9);
#undef DO_ITER

			blk.m_endpoints[0] = pTable_r[best_mapping].m_lo;
			blk.m_endpoints[1] = pTable_r[best_mapping].m_hi;

			blk.m_endpoints[2] = pTable_g[best_mapping].m_lo;
			blk.m_endpoints[3] = pTable_g[best_mapping].m_hi;

			blk.m_endpoints[4] = pTable_b[best_mapping].m_lo;
			blk.m_endpoints[5] = pTable_b[best_mapping].m_hi;

			int s0 = blk.m_endpoints[0] + blk.m_endpoints[2] + blk.m_endpoints[4];
			int s1 = blk.m_endpoints[1] + blk.m_endpoints[3] + blk.m_endpoints[5];
			bool invert = false;

			if (s1 < s0)
			{
				std::swap(blk.m_endpoints[0], blk.m_endpoints[1]);
				std::swap(blk.m_endpoints[2], blk.m_endpoints[3]);
				std::swap(blk.m_endpoints[4], blk.m_endpoints[5]);
				invert = true;
			}

			const uint8_t* pSelectors_xlat = &g_etc1_to_astc_selector_mappings[best_mapping][0];

			for (uint32_t y = 0; y < 4; y++)
			{
				for (uint32_t x = 0; x < 4; x++)
				{
					uint32_t s = pSelector->get_selector(x, y);
					uint32_t as = pSelectors_xlat[s];
					if (invert)
						as = 3 - as;

					blk.m_weights[x + y * 4] = static_cast<uint8_t>(as);
				} // x
			} // y

			// Now pack to ASTC
			astc_pack_block_cem_8_weight_range2(reinterpret_cast<uint32_t*>(pDst_block), &blk);
			return;
		}
#endif //#if BASISD_SUPPORT_ASTC_HIGHER_OPAQUE_QUALITY

		// Nothing else worked, so fall back to CEM Mode 12 (LDR RGBA Direct), [0,47] endpoints, weight range 2 (2-bit weights), dual planes.
		// This mode can handle everything, but at slightly less quality than BC1.
		if (transcode_alpha)
		{
			const endpoint& alpha_endpoint = pEndpoint_codebook[((uint16_t*)pDst_block)[0]];
			const selector& alpha_selectors = pSelector_codebook[((uint16_t*)pDst_block)[1]];

			const color32& alpha_base_color = alpha_endpoint.m_color5;
			const uint32_t alpha_inten_table = alpha_endpoint.m_inten5;

			const uint32_t alpha_low_selector = alpha_selectors.m_lo_selector;
			const uint32_t alpha_high_selector = alpha_selectors.m_hi_selector;

			if (alpha_low_selector == alpha_high_selector)
			{
				// Solid alpha block - use precomputed tables.
				int alpha_block_colors[4];
				decoder_etc_block::get_block_colors5_g(alpha_block_colors, alpha_base_color, alpha_inten_table);

				const uint32_t g = alpha_block_colors[alpha_low_selector];

				blk.m_endpoints[6] = g_astc_single_color_encoding_1[g].m_lo;
				blk.m_endpoints[7] = g_astc_single_color_encoding_1[g].m_hi;

				for (uint32_t i = 0; i < 16; i++)
					blk.m_weights[i * 2 + 1] = 1;
			}
			else if ((alpha_inten_table >= 7) && (alpha_selectors.m_num_unique_selectors == 2) && (alpha_low_selector == 0) && (alpha_high_selector == 3))
			{
				// Handle outlier case where only the two outer colors are used with inten table 7.
				color32 alpha_block_colors[4];

				decoder_etc_block::get_block_colors5(alpha_block_colors, alpha_base_color, alpha_inten_table);

				const uint32_t g0 = alpha_block_colors[0].g;
				const uint32_t g1 = alpha_block_colors[3].g;

				blk.m_endpoints[6] = g_astc_single_color_encoding_0[g0];
				blk.m_endpoints[7] = g_astc_single_color_encoding_0[g1];

				for (uint32_t y = 0; y < 4; y++)
				{
					for (uint32_t x = 0; x < 4; x++)
					{
						uint32_t s = alpha_selectors.get_selector(x, y);
						uint32_t as = (s == alpha_high_selector) ? 3 : 0;

						blk.m_weights[(x + y * 4) * 2 + 1] = static_cast<uint8_t>(as);
					} // x
				} // y
			}
			else
			{
				// Convert ETC1S alpha
				const uint32_t alpha_selector_range_table = g_etc1_to_astc_selector_range_index[alpha_low_selector][alpha_high_selector];
								
				//[32][8][RANGES][MAPPING]
				const etc1_to_astc_solution* pTable_g = &g_etc1_to_astc[(alpha_inten_table * 32 + alpha_base_color.g) * (NUM_ETC1_TO_ASTC_SELECTOR_RANGES * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS) + alpha_selector_range_table * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];

				const uint32_t best_mapping = g_etc1_to_astc_best_grayscale_mapping[alpha_base_color.g][alpha_inten_table][alpha_selector_range_table];

				blk.m_endpoints[6] = pTable_g[best_mapping].m_lo;
				blk.m_endpoints[7] = pTable_g[best_mapping].m_hi;

				const uint8_t* pSelectors_xlat = &g_etc1_to_astc_selector_mappings[best_mapping][0];

				for (uint32_t y = 0; y < 4; y++)
				{
					for (uint32_t x = 0; x < 4; x++)
					{
						uint32_t s = alpha_selectors.get_selector(x, y);
						uint32_t as = pSelectors_xlat[s];

						blk.m_weights[(x + y * 4) * 2 + 1] = static_cast<uint8_t>(as);
					} // x
				} // y
			}
		}
		else
		{
			// No alpha slice - set output alpha to all 255's
			// 1 is 255 when dequantized
			blk.m_endpoints[6] = 1;
			blk.m_endpoints[7] = 1;

			for (uint32_t i = 0; i < 16; i++)
				blk.m_weights[i * 2 + 1] = 0;
		}

		if (low_selector == high_selector)
		{
			// Solid color block - use precomputed tables of optimal endpoints assuming selector weights are all 1.
			color32 block_colors[4];

			decoder_etc_block::get_block_colors5(block_colors, base_color, inten_table);

			const uint32_t r = block_colors[low_selector].r;
			const uint32_t g = block_colors[low_selector].g;
			const uint32_t b = block_colors[low_selector].b;
						
			blk.m_endpoints[0] = g_astc_single_color_encoding_1[r].m_lo;
			blk.m_endpoints[1] = g_astc_single_color_encoding_1[r].m_hi;

			blk.m_endpoints[2] = g_astc_single_color_encoding_1[g].m_lo;
			blk.m_endpoints[3] = g_astc_single_color_encoding_1[g].m_hi;

			blk.m_endpoints[4] = g_astc_single_color_encoding_1[b].m_lo;
			blk.m_endpoints[5] = g_astc_single_color_encoding_1[b].m_hi;

			int s0 = g_ise_to_unquant[blk.m_endpoints[0]] + g_ise_to_unquant[blk.m_endpoints[2]] + g_ise_to_unquant[blk.m_endpoints[4]];
			int s1 = g_ise_to_unquant[blk.m_endpoints[1]] + g_ise_to_unquant[blk.m_endpoints[3]] + g_ise_to_unquant[blk.m_endpoints[5]];
			bool invert = false;

			if (s1 < s0)
			{
				std::swap(blk.m_endpoints[0], blk.m_endpoints[1]);
				std::swap(blk.m_endpoints[2], blk.m_endpoints[3]);
				std::swap(blk.m_endpoints[4], blk.m_endpoints[5]);
				invert = true;
			}

			for (uint32_t i = 0; i < 16; i++)
				blk.m_weights[i * 2] = invert ? 2 : 1;
		}
		else if ((inten_table >= 7) && (pSelector->m_num_unique_selectors == 2) && (pSelector->m_lo_selector == 0) && (pSelector->m_hi_selector == 3))
		{
			// Handle outlier case where only the two outer colors are used with inten table 7.
			color32 block_colors[4];

			decoder_etc_block::get_block_colors5(block_colors, base_color, inten_table);

			const uint32_t r0 = block_colors[0].r;
			const uint32_t g0 = block_colors[0].g;
			const uint32_t b0 = block_colors[0].b;

			const uint32_t r1 = block_colors[3].r;
			const uint32_t g1 = block_colors[3].g;
			const uint32_t b1 = block_colors[3].b;

			blk.m_endpoints[0] = g_astc_single_color_encoding_0[r0];
			blk.m_endpoints[1] = g_astc_single_color_encoding_0[r1];

			blk.m_endpoints[2] = g_astc_single_color_encoding_0[g0];
			blk.m_endpoints[3] = g_astc_single_color_encoding_0[g1];

			blk.m_endpoints[4] = g_astc_single_color_encoding_0[b0];
			blk.m_endpoints[5] = g_astc_single_color_encoding_0[b1];

			int s0 = g_ise_to_unquant[blk.m_endpoints[0]] + g_ise_to_unquant[blk.m_endpoints[2]] + g_ise_to_unquant[blk.m_endpoints[4]];
			int s1 = g_ise_to_unquant[blk.m_endpoints[1]] + g_ise_to_unquant[blk.m_endpoints[3]] + g_ise_to_unquant[blk.m_endpoints[5]];
			bool invert = false;

			if (s1 < s0)
			{
				std::swap(blk.m_endpoints[0], blk.m_endpoints[1]);
				std::swap(blk.m_endpoints[2], blk.m_endpoints[3]);
				std::swap(blk.m_endpoints[4], blk.m_endpoints[5]);
				invert = true;
			}

			for (uint32_t y = 0; y < 4; y++)
			{
				for (uint32_t x = 0; x < 4; x++)
				{
					uint32_t s = pSelector->get_selector(x, y);
					uint32_t as = (s == low_selector) ? 0 : 3;

					if (invert)
						as = 3 - as;

					blk.m_weights[(x + y * 4) * 2] = static_cast<uint8_t>(as);
				} // x
			} // y
		}
		else
		{
			// Convert ETC1S color
			const uint32_t selector_range_table = g_etc1_to_astc_selector_range_index[low_selector][high_selector];

			//[32][8][RANGES][MAPPING]
			const etc1_to_astc_solution* pTable_r = &g_etc1_to_astc[(inten_table * 32 + base_color.r) * (NUM_ETC1_TO_ASTC_SELECTOR_RANGES * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];
			const etc1_to_astc_solution* pTable_g = &g_etc1_to_astc[(inten_table * 32 + base_color.g) * (NUM_ETC1_TO_ASTC_SELECTOR_RANGES * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];
			const etc1_to_astc_solution* pTable_b = &g_etc1_to_astc[(inten_table * 32 + base_color.b) * (NUM_ETC1_TO_ASTC_SELECTOR_RANGES * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];

			uint32_t best_err = UINT_MAX;
			uint32_t best_mapping = 0;

			assert(NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS == 10);
#define DO_ITER(m) { uint32_t total_err = pTable_r[m].m_err + pTable_g[m].m_err + pTable_b[m].m_err; if (total_err < best_err) { best_err = total_err; best_mapping = m; } }
			DO_ITER(0); DO_ITER(1); DO_ITER(2); DO_ITER(3); DO_ITER(4);
			DO_ITER(5); DO_ITER(6); DO_ITER(7); DO_ITER(8); DO_ITER(9);
#undef DO_ITER

			blk.m_endpoints[0] = pTable_r[best_mapping].m_lo;
			blk.m_endpoints[1] = pTable_r[best_mapping].m_hi;

			blk.m_endpoints[2] = pTable_g[best_mapping].m_lo;
			blk.m_endpoints[3] = pTable_g[best_mapping].m_hi;

			blk.m_endpoints[4] = pTable_b[best_mapping].m_lo;
			blk.m_endpoints[5] = pTable_b[best_mapping].m_hi;
						
			int s0 = g_ise_to_unquant[blk.m_endpoints[0]] + g_ise_to_unquant[blk.m_endpoints[2]] + g_ise_to_unquant[blk.m_endpoints[4]];
			int s1 = g_ise_to_unquant[blk.m_endpoints[1]] + g_ise_to_unquant[blk.m_endpoints[3]] + g_ise_to_unquant[blk.m_endpoints[5]];
			bool invert = false;

			if (s1 < s0)
			{
				std::swap(blk.m_endpoints[0], blk.m_endpoints[1]);
				std::swap(blk.m_endpoints[2], blk.m_endpoints[3]);
				std::swap(blk.m_endpoints[4], blk.m_endpoints[5]);
				invert = true;
			}

			const uint8_t* pSelectors_xlat = &g_etc1_to_astc_selector_mappings[best_mapping][0];

			for (uint32_t y = 0; y < 4; y++)
			{
				for (uint32_t x = 0; x < 4; x++)
				{
					uint32_t s = pSelector->get_selector(x, y);
					uint32_t as = pSelectors_xlat[s];
					if (invert)
						as = 3 - as;

					blk.m_weights[(x + y * 4) * 2] = static_cast<uint8_t>(as);
				} // x
			} // y
		}

		// Now pack to ASTC
		astc_pack_block_cem_12_weight_range2(reinterpret_cast<uint32_t *>(pDst_block), &blk);
	}
#endif

#if BASISD_SUPPORT_ATC
	// ATC and PVRTC2 both use these tables.
	struct etc1s_to_atc_solution
	{
		uint8_t m_lo;
		uint8_t m_hi;
		uint16_t m_err;
	};

	static dxt_selector_range g_etc1s_to_atc_selector_ranges[] =
	{
		{ 0, 3 },
		{ 1, 3 },
		{ 0, 2 },
		{ 1, 2 },
		{ 2, 3 },
		{ 0, 1 },
	};

	const uint32_t NUM_ETC1S_TO_ATC_SELECTOR_RANGES = sizeof(g_etc1s_to_atc_selector_ranges) / sizeof(g_etc1s_to_atc_selector_ranges[0]);

	static uint32_t g_etc1s_to_atc_selector_range_index[4][4];

	const uint32_t NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS = 10;
	static const uint8_t g_etc1s_to_atc_selector_mappings[NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS][4] =
	{
		{ 0, 0, 1, 1 },
		{ 0, 0, 1, 2 },
		{ 0, 0, 1, 3 },
		{ 0, 0, 2, 3 },
		{ 0, 1, 1, 1 },
		{ 0, 1, 2, 2 },
		{ 0, 1, 2, 3 }, //6 - identity
		{ 0, 2, 3, 3 },
		{ 1, 2, 2, 2 },
		{ 1, 2, 3, 3 },
	};
	const uint32_t ATC_IDENTITY_SELECTOR_MAPPING_INDEX = 6;

#if BASISD_SUPPORT_PVRTC2
	static const etc1s_to_atc_solution g_etc1s_to_pvrtc2_45[32 * 8 * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS * NUM_ETC1S_TO_ATC_SELECTOR_RANGES] = {
#include "basisu_transcoder_tables_pvrtc2_45.inc"
	};

#if 0
	static const etc1s_to_atc_solution g_etc1s_to_pvrtc2_alpha_33[32 * 8 * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS * NUM_ETC1S_TO_ATC_SELECTOR_RANGES] = {
#include "basisu_transcoder_tables_pvrtc2_alpha_33.inc"
	};
#endif

#endif

	static const etc1s_to_atc_solution g_etc1s_to_atc_55[32 * 8 * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS * NUM_ETC1S_TO_ATC_SELECTOR_RANGES] = {
#include "basisu_transcoder_tables_atc_55.inc"
	};

	static const etc1s_to_atc_solution g_etc1s_to_atc_56[32 * 8 * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS * NUM_ETC1S_TO_ATC_SELECTOR_RANGES] = {
#include "basisu_transcoder_tables_atc_56.inc"
	};

	struct atc_match_entry
	{
		uint8_t m_lo;
		uint8_t m_hi;
	};
	static atc_match_entry g_pvrtc2_match45_equals_1[256], g_atc_match55_equals_1[256], g_atc_match56_equals_1[256]; // selector 1
	static atc_match_entry g_pvrtc2_match4[256], g_atc_match5[256], g_atc_match6[256];

	static void prepare_atc_single_color_table(atc_match_entry* pTable, int size0, int size1, int sel)
	{
		for (int i = 0; i < 256; i++)
		{
			int lowest_e = 256;
			for (int lo = 0; lo < size0; lo++)
			{
				int lo_e = lo;
				if (size0 == 16)
				{
					lo_e = (lo_e << 1) | (lo_e >> 3);
					lo_e = (lo_e << 3) | (lo_e >> 2);
				}
				else if (size0 == 32)
					lo_e = (lo_e << 3) | (lo_e >> 2);
				else
					lo_e = (lo_e << 2) | (lo_e >> 4);

				for (int hi = 0; hi < size1; hi++)
				{
					int hi_e = hi;
					if (size1 == 16)
					{
						// This is only for PVRTC2 - expand to 5 then 8
						hi_e = (hi_e << 1) | (hi_e >> 3);
						hi_e = (hi_e << 3) | (hi_e >> 2);
					}
					else if (size1 == 32)
						hi_e = (hi_e << 3) | (hi_e >> 2);
					else
						hi_e = (hi_e << 2) | (hi_e >> 4);

					int e;

					if (sel == 1)
					{
						// Selector 1
						e = abs(((lo_e * 5 + hi_e * 3) / 8) - i);
					}
					else
					{
						assert(sel == 3);

						// Selector 3
						e = abs(hi_e - i);
					}

					if (e < lowest_e)
					{
						pTable[i].m_lo = static_cast<uint8_t>(lo);
						pTable[i].m_hi = static_cast<uint8_t>(hi);

						lowest_e = e;
					}

				} // hi
			} // lo
		} // i
	}

	static void transcoder_init_atc()
	{
		prepare_atc_single_color_table(g_pvrtc2_match45_equals_1, 16, 32, 1);
		prepare_atc_single_color_table(g_atc_match55_equals_1, 32, 32, 1); 
		prepare_atc_single_color_table(g_atc_match56_equals_1, 32, 64, 1); 

		prepare_atc_single_color_table(g_pvrtc2_match4, 1, 16, 3);
		prepare_atc_single_color_table(g_atc_match5, 1, 32, 3);
		prepare_atc_single_color_table(g_atc_match6, 1, 64, 3);

		for (uint32_t i = 0; i < NUM_ETC1S_TO_ATC_SELECTOR_RANGES; i++)
		{
			uint32_t l = g_etc1s_to_atc_selector_ranges[i].m_low;
			uint32_t h = g_etc1s_to_atc_selector_ranges[i].m_high;
			g_etc1s_to_atc_selector_range_index[l][h] = i;
		}
	}

	struct atc_block
	{
		uint8_t m_lo[2];
		uint8_t m_hi[2];
		uint8_t m_sels[4];

		void set_low_color(uint32_t r, uint32_t g, uint32_t b)
		{
			assert((r < 32) && (g < 32) && (b < 32));
			uint32_t x = (r << 10) | (g << 5) | b;
			m_lo[0] = x & 0xFF;
			m_lo[1] = (x >> 8) & 0xFF;
		}

		void set_high_color(uint32_t r, uint32_t g, uint32_t b)
		{
			assert((r < 32) && (g < 64) && (b < 32));
			uint32_t x = (r << 11) | (g << 5) | b;
			m_hi[0] = x & 0xFF;
			m_hi[1] = (x >> 8) & 0xFF;
		}
	};

	static void convert_etc1s_to_atc(void* pDst, const endpoint* pEndpoints, const selector* pSelector)
	{
		atc_block* pBlock = static_cast<atc_block*>(pDst);

		const uint32_t low_selector = pSelector->m_lo_selector;
		const uint32_t high_selector = pSelector->m_hi_selector;

		const color32& base_color = pEndpoints->m_color5;
		const uint32_t inten_table = pEndpoints->m_inten5;

		if (low_selector == high_selector)
		{
			uint32_t r, g, b;
			decoder_etc_block::get_block_color5(base_color, inten_table, low_selector, r, g, b);

			pBlock->set_low_color(g_atc_match55_equals_1[r].m_lo, g_atc_match56_equals_1[g].m_lo, g_atc_match55_equals_1[b].m_lo);
			pBlock->set_high_color(g_atc_match55_equals_1[r].m_hi, g_atc_match56_equals_1[g].m_hi, g_atc_match55_equals_1[b].m_hi);
						
			pBlock->m_sels[0] = 0x55;
			pBlock->m_sels[1] = 0x55;
			pBlock->m_sels[2] = 0x55;
			pBlock->m_sels[3] = 0x55;

			return;
		}
		else if ((inten_table >= 7) && (pSelector->m_num_unique_selectors == 2) && (pSelector->m_lo_selector == 0) && (pSelector->m_hi_selector == 3))
		{
			color32 block_colors[4];
			decoder_etc_block::get_block_colors5(block_colors, base_color, inten_table);

			const uint32_t r0 = block_colors[0].r;
			const uint32_t g0 = block_colors[0].g;
			const uint32_t b0 = block_colors[0].b;

			const uint32_t r1 = block_colors[3].r;
			const uint32_t g1 = block_colors[3].g;
			const uint32_t b1 = block_colors[3].b;

			pBlock->set_low_color(g_atc_match5[r0].m_hi, g_atc_match5[g0].m_hi, g_atc_match5[b0].m_hi);
			pBlock->set_high_color(g_atc_match5[r1].m_hi, g_atc_match6[g1].m_hi, g_atc_match5[b1].m_hi);

			pBlock->m_sels[0] = pSelector->m_selectors[0];
			pBlock->m_sels[1] = pSelector->m_selectors[1];
			pBlock->m_sels[2] = pSelector->m_selectors[2];
			pBlock->m_sels[3] = pSelector->m_selectors[3];

			return;
		}

		const uint32_t selector_range_table = g_etc1s_to_atc_selector_range_index[low_selector][high_selector];

		//[32][8][RANGES][MAPPING]
		const etc1s_to_atc_solution* pTable_r = &g_etc1s_to_atc_55[(inten_table * 32 + base_color.r) * (NUM_ETC1S_TO_ATC_SELECTOR_RANGES * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS];
		const etc1s_to_atc_solution* pTable_g = &g_etc1s_to_atc_56[(inten_table * 32 + base_color.g) * (NUM_ETC1S_TO_ATC_SELECTOR_RANGES * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS];
		const etc1s_to_atc_solution* pTable_b = &g_etc1s_to_atc_55[(inten_table * 32 + base_color.b) * (NUM_ETC1S_TO_ATC_SELECTOR_RANGES * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS];

		uint32_t best_err = UINT_MAX;
		uint32_t best_mapping = 0;

		assert(NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS == 10);
#define DO_ITER(m) { uint32_t total_err = pTable_r[m].m_err + pTable_g[m].m_err + pTable_b[m].m_err; if (total_err < best_err) { best_err = total_err; best_mapping = m; } }
		DO_ITER(0); DO_ITER(1); DO_ITER(2); DO_ITER(3); DO_ITER(4);
		DO_ITER(5); DO_ITER(6); DO_ITER(7); DO_ITER(8); DO_ITER(9);
#undef DO_ITER

		pBlock->set_low_color(pTable_r[best_mapping].m_lo, pTable_g[best_mapping].m_lo, pTable_b[best_mapping].m_lo);
		pBlock->set_high_color(pTable_r[best_mapping].m_hi, pTable_g[best_mapping].m_hi, pTable_b[best_mapping].m_hi);

		if (ATC_IDENTITY_SELECTOR_MAPPING_INDEX == best_mapping)
		{
			pBlock->m_sels[0] = pSelector->m_selectors[0];
			pBlock->m_sels[1] = pSelector->m_selectors[1];
			pBlock->m_sels[2] = pSelector->m_selectors[2];
			pBlock->m_sels[3] = pSelector->m_selectors[3];
		}
		else
		{
			const uint8_t* pSelectors_xlat = &g_etc1s_to_atc_selector_mappings[best_mapping][0];

			const uint32_t sel_bits0 = pSelector->m_selectors[0];
			const uint32_t sel_bits1 = pSelector->m_selectors[1];
			const uint32_t sel_bits2 = pSelector->m_selectors[2];
			const uint32_t sel_bits3 = pSelector->m_selectors[3];

			uint32_t atc_sels0 = 0, atc_sels1 = 0, atc_sels2 = 0, atc_sels3 = 0;

#define DO_X(x) { \
			const uint32_t x_shift = (x) * 2; \
			atc_sels0 |= (pSelectors_xlat[(sel_bits0 >> x_shift) & 3] << x_shift); \
			atc_sels1 |= (pSelectors_xlat[(sel_bits1 >> x_shift) & 3] << x_shift); \
			atc_sels2 |= (pSelectors_xlat[(sel_bits2 >> x_shift) & 3] << x_shift); \
			atc_sels3 |= (pSelectors_xlat[(sel_bits3 >> x_shift) & 3] << x_shift); }

			DO_X(0);
			DO_X(1);
			DO_X(2);
			DO_X(3);
#undef DO_X

			pBlock->m_sels[0] = (uint8_t)atc_sels0;
			pBlock->m_sels[1] = (uint8_t)atc_sels1;
			pBlock->m_sels[2] = (uint8_t)atc_sels2;
			pBlock->m_sels[3] = (uint8_t)atc_sels3;
		}
	}

#if BASISD_WRITE_NEW_ATC_TABLES
	static void create_etc1s_to_atc_conversion_tables()
	{
		// ATC 55
		FILE* pFile = nullptr;
		fopen_s(&pFile, "basisu_transcoder_tables_atc_55.inc", "w");

		uint32_t n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1S_TO_ATC_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1s_to_atc_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1s_to_atc_selector_ranges[sr].m_high;

					for (uint32_t m = 0; m < NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS; m++)
					{
						uint32_t best_lo = 0;
						uint32_t best_hi = 0;
						uint64_t best_err = UINT64_MAX;

						for (uint32_t hi = 0; hi <= 31; hi++)
						{
							for (uint32_t lo = 0; lo <= 31; lo++)
							{
								uint32_t colors[4];

								colors[0] = (lo << 3) | (lo >> 2);
								colors[3] = (hi << 3) | (hi >> 2);

								colors[1] = (colors[0] * 5 + colors[3] * 3) / 8;
								colors[2] = (colors[3] * 5 + colors[0] * 3) / 8;

								uint64_t total_err = 0;

								for (uint32_t s = low_selector; s <= high_selector; s++)
								{
									int err = block_colors[s].g - colors[g_etc1s_to_atc_selector_mappings[m][s]];

									int err_scale = 1;
									// Special case when the intensity table is 7, low_selector is 0, and high_selector is 3. In this extreme case, it's likely the encoder is trying to strongly favor 
									// the low/high selectors which are clamping to either 0 or 255.
									if (((inten == 7) && (low_selector == 0) && (high_selector == 3)) && ((s == 0) || (s == 3)))
										err_scale = 5;

									total_err += (err * err) * err_scale;
								}

								if (total_err < best_err)
								{
									best_err = total_err;
									best_lo = lo;
									best_hi = hi;
								}
							}
						}

						//assert(best_err <= 0xFFFF);
						best_err = basisu::minimum<uint32_t>(best_err, 0xFFFF);

						fprintf(pFile, "{%u,%u,%u},", best_lo, best_hi, (uint32_t)best_err);
						n++;
						if ((n & 31) == 31)
							fprintf(pFile, "\n");
					} // m
				} // sr
			} // g
		} // inten

		fclose(pFile);
		pFile = nullptr;

		// ATC 56
		fopen_s(&pFile, "basisu_transcoder_tables_atc_56.inc", "w");

		n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1S_TO_ATC_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1s_to_atc_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1s_to_atc_selector_ranges[sr].m_high;

					for (uint32_t m = 0; m < NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS; m++)
					{
						uint32_t best_lo = 0;
						uint32_t best_hi = 0;
						uint64_t best_err = UINT64_MAX;

						for (uint32_t hi = 0; hi <= 63; hi++)
						{
							for (uint32_t lo = 0; lo <= 31; lo++)
							{
								uint32_t colors[4];

								colors[0] = (lo << 3) | (lo >> 2);
								colors[3] = (hi << 2) | (hi >> 4);

								colors[1] = (colors[0] * 5 + colors[3] * 3) / 8;
								colors[2] = (colors[3] * 5 + colors[0] * 3) / 8;

								uint64_t total_err = 0;

								for (uint32_t s = low_selector; s <= high_selector; s++)
								{
									int err = block_colors[s].g - colors[g_etc1s_to_atc_selector_mappings[m][s]];

									int err_scale = 1;
									// Special case when the intensity table is 7, low_selector is 0, and high_selector is 3. In this extreme case, it's likely the encoder is trying to strongly favor 
									// the low/high selectors which are clamping to either 0 or 255.
									if (((inten == 7) && (low_selector == 0) && (high_selector == 3)) && ((s == 0) || (s == 3)))
										err_scale = 5;

									total_err += (err * err) * err_scale;
								}

								if (total_err < best_err)
								{
									best_err = total_err;
									best_lo = lo;
									best_hi = hi;
								}
							}
						}

						//assert(best_err <= 0xFFFF);
						best_err = basisu::minimum<uint32_t>(best_err, 0xFFFF);

						fprintf(pFile, "{%u,%u,%u},", best_lo, best_hi, (uint32_t)best_err);
						n++;
						if ((n & 31) == 31)
							fprintf(pFile, "\n");
					} // m
				} // sr
			} // g
		} // inten

		fclose(pFile);
		
		// PVRTC2 45
		fopen_s(&pFile, "basisu_transcoder_tables_pvrtc2_45.inc", "w");

		n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1S_TO_ATC_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1s_to_atc_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1s_to_atc_selector_ranges[sr].m_high;

					for (uint32_t m = 0; m < NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS; m++)
					{
						uint32_t best_lo = 0;
						uint32_t best_hi = 0;
						uint64_t best_err = UINT64_MAX;

						for (uint32_t hi = 0; hi <= 31; hi++)
						{
							for (uint32_t lo = 0; lo <= 15; lo++)
							{
								uint32_t colors[4];

								colors[0] = (lo << 1) | (lo >> 3);
								colors[0] = (colors[0] << 3) | (colors[0] >> 2);

								colors[3] = (hi << 3) | (hi >> 2);

								colors[1] = (colors[0] * 5 + colors[3] * 3) / 8;
								colors[2] = (colors[3] * 5 + colors[0] * 3) / 8;

								uint64_t total_err = 0;

								for (uint32_t s = low_selector; s <= high_selector; s++)
								{
									int err = block_colors[s].g - colors[g_etc1s_to_atc_selector_mappings[m][s]];

									int err_scale = 1;
									// Special case when the intensity table is 7, low_selector is 0, and high_selector is 3. In this extreme case, it's likely the encoder is trying to strongly favor 
									// the low/high selectors which are clamping to either 0 or 255.
									if (((inten == 7) && (low_selector == 0) && (high_selector == 3)) && ((s == 0) || (s == 3)))
										err_scale = 5;

									total_err += (err * err) * err_scale;
								}

								if (total_err < best_err)
								{
									best_err = total_err;
									best_lo = lo;
									best_hi = hi;
								}
							}
						}

						//assert(best_err <= 0xFFFF);
						best_err = basisu::minimum<uint32_t>(best_err, 0xFFFF);

						fprintf(pFile, "{%u,%u,%u},", best_lo, best_hi, (uint32_t)best_err);
						n++;
						if ((n & 31) == 31)
							fprintf(pFile, "\n");
					} // m
				} // sr
			} // g
		} // inten

		fclose(pFile);

#if 0
		// PVRTC2 34
		fopen_s(&pFile, "basisu_transcoder_tables_pvrtc2_34.inc", "w");

		n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1S_TO_ATC_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1s_to_atc_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1s_to_atc_selector_ranges[sr].m_high;

					for (uint32_t m = 0; m < NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS; m++)
					{
						uint32_t best_lo = 0;
						uint32_t best_hi = 0;
						uint64_t best_err = UINT64_MAX;

						for (uint32_t hi = 0; hi <= 15; hi++)
						{
							for (uint32_t lo = 0; lo <= 7; lo++)
							{
								uint32_t colors[4];

								colors[0] = (lo << 2) | (lo >> 1);
								colors[0] = (colors[0] << 3) | (colors[0] >> 2);

								colors[3] = (hi << 1) | (hi >> 3);
								colors[3] = (colors[3] << 3) | (colors[3] >> 2);

								colors[1] = (colors[0] * 5 + colors[3] * 3) / 8;
								colors[2] = (colors[3] * 5 + colors[0] * 3) / 8;

								uint64_t total_err = 0;

								for (uint32_t s = low_selector; s <= high_selector; s++)
								{
									int err = block_colors[s].g - colors[g_etc1s_to_atc_selector_mappings[m][s]];

									int err_scale = 1;
									// Special case when the intensity table is 7, low_selector is 0, and high_selector is 3. In this extreme case, it's likely the encoder is trying to strongly favor 
									// the low/high selectors which are clamping to either 0 or 255.
									if (((inten == 7) && (low_selector == 0) && (high_selector == 3)) && ((s == 0) || (s == 3)))
										err_scale = 5;

									total_err += (err * err) * err_scale;
								}

								if (total_err < best_err)
								{
									best_err = total_err;
									best_lo = lo;
									best_hi = hi;
								}
							}
						}

						//assert(best_err <= 0xFFFF);
						best_err = basisu::minimum<uint32_t>(best_err, 0xFFFF);

						fprintf(pFile, "{%u,%u,%u},", best_lo, best_hi, (uint32_t)best_err);
						n++;
						if ((n & 31) == 31)
							fprintf(pFile, "\n");
					} // m
				} // sr
			} // g
		} // inten

		fclose(pFile);
#endif
#if 0
		// PVRTC2 44
		fopen_s(&pFile, "basisu_transcoder_tables_pvrtc2_44.inc", "w");

		n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1S_TO_ATC_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1s_to_atc_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1s_to_atc_selector_ranges[sr].m_high;

					for (uint32_t m = 0; m < NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS; m++)
					{
						uint32_t best_lo = 0;
						uint32_t best_hi = 0;
						uint64_t best_err = UINT64_MAX;

						for (uint32_t hi = 0; hi <= 15; hi++)
						{
							for (uint32_t lo = 0; lo <= 15; lo++)
							{
								uint32_t colors[4];

								colors[0] = (lo << 1) | (lo >> 3);
								colors[0] = (colors[0] << 3) | (colors[0] >> 2);

								colors[3] = (hi << 1) | (hi >> 3);
								colors[3] = (colors[3] << 3) | (colors[3] >> 2);

								colors[1] = (colors[0] * 5 + colors[3] * 3) / 8;
								colors[2] = (colors[3] * 5 + colors[0] * 3) / 8;

								uint64_t total_err = 0;

								for (uint32_t s = low_selector; s <= high_selector; s++)
								{
									int err = block_colors[s].g - colors[g_etc1s_to_atc_selector_mappings[m][s]];

									int err_scale = 1;
									// Special case when the intensity table is 7, low_selector is 0, and high_selector is 3. In this extreme case, it's likely the encoder is trying to strongly favor 
									// the low/high selectors which are clamping to either 0 or 255.
									if (((inten == 7) && (low_selector == 0) && (high_selector == 3)) && ((s == 0) || (s == 3)))
										err_scale = 5;

									total_err += (err * err) * err_scale;
								}

								if (total_err < best_err)
								{
									best_err = total_err;
									best_lo = lo;
									best_hi = hi;
								}
							}
						}

						//assert(best_err <= 0xFFFF);
						best_err = basisu::minimum<uint32_t>(best_err, 0xFFFF);

						fprintf(pFile, "{%u,%u,%u},", best_lo, best_hi, (uint32_t)best_err);
						n++;
						if ((n & 31) == 31)
							fprintf(pFile, "\n");
					} // m
				} // sr
			} // g
		} // inten

		fclose(pFile);
#endif

		// PVRTC2 alpha 33
		fopen_s(&pFile, "basisu_transcoder_tables_pvrtc2_alpha_33.inc", "w");

		n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1S_TO_ATC_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1s_to_atc_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1s_to_atc_selector_ranges[sr].m_high;

					for (uint32_t m = 0; m < NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS; m++)
					{
						uint32_t best_lo = 0;
						uint32_t best_hi = 0;
						uint64_t best_err = UINT64_MAX;

						for (uint32_t hi = 0; hi <= 7; hi++)
						{
							for (uint32_t lo = 0; lo <= 7; lo++)
							{
								uint32_t colors[4];

								colors[0] = (lo << 1);
								colors[0] = (colors[0] << 4) | colors[0];

								colors[3] = (hi << 1) | 1;
								colors[3] = (colors[3] << 4) | colors[3];

								colors[1] = (colors[0] * 5 + colors[3] * 3) / 8;
								colors[2] = (colors[3] * 5 + colors[0] * 3) / 8;

								uint64_t total_err = 0;

								for (uint32_t s = low_selector; s <= high_selector; s++)
								{
									int err = block_colors[s].g - colors[g_etc1s_to_atc_selector_mappings[m][s]];

									int err_scale = 1;
									// Special case when the intensity table is 7, low_selector is 0, and high_selector is 3. In this extreme case, it's likely the encoder is trying to strongly favor 
									// the low/high selectors which are clamping to either 0 or 255.
									if (((inten == 7) && (low_selector == 0) && (high_selector == 3)) && ((s == 0) || (s == 3)))
										err_scale = 5;

									total_err += (err * err) * err_scale;
								}

								if (total_err < best_err)
								{
									best_err = total_err;
									best_lo = lo;
									best_hi = hi;
								}
							}
						}

						//assert(best_err <= 0xFFFF);
						best_err = basisu::minimum<uint32_t>(best_err, 0xFFFF);

						fprintf(pFile, "{%u,%u,%u},", best_lo, best_hi, (uint32_t)best_err);
						n++;
						if ((n & 31) == 31)
							fprintf(pFile, "\n");
					} // m
				} // sr
			} // g
		} // inten

		fclose(pFile);
	}
#endif // BASISD_WRITE_NEW_ATC_TABLES

#endif // BASISD_SUPPORT_ATC

#if BASISD_SUPPORT_PVRTC2
	struct pvrtc2_block
	{
		uint8_t m_modulation[4];

		union
		{
			union
			{
				// Opaque mode: RGB colora=554 and colorb=555
				struct
				{
					uint32_t m_mod_flag : 1;
					uint32_t m_blue_a : 4;
					uint32_t m_green_a : 5;
					uint32_t m_red_a : 5;
					uint32_t m_hard_flag : 1;
					uint32_t m_blue_b : 5;
					uint32_t m_green_b : 5;
					uint32_t m_red_b : 5;
					uint32_t m_opaque_flag : 1;

				} m_opaque_color_data;

				// Transparent mode: RGBA colora=4433 and colorb=4443
				struct
				{
					uint32_t m_mod_flag : 1;
					uint32_t m_blue_a : 3;
					uint32_t m_green_a : 4;
					uint32_t m_red_a : 4;
					uint32_t m_alpha_a : 3;
					uint32_t m_hard_flag : 1;
					uint32_t m_blue_b : 4;
					uint32_t m_green_b : 4;
					uint32_t m_red_b : 4;
					uint32_t m_alpha_b : 3;
					uint32_t m_opaque_flag : 1;

				} m_trans_color_data;
			};

			uint32_t m_color_data_bits;
		};

		// 554
		void set_low_color(uint32_t r, uint32_t g, uint32_t b)
		{
			assert((r < 32) && (g < 32) && (b < 16));
			m_opaque_color_data.m_red_a = r;
			m_opaque_color_data.m_green_a = g;
			m_opaque_color_data.m_blue_a = b;
		}

		// 555
		void set_high_color(uint32_t r, uint32_t g, uint32_t b)
		{
			assert((r < 32) && (g < 32) && (b < 32));
			m_opaque_color_data.m_red_b = r;
			m_opaque_color_data.m_green_b = g;
			m_opaque_color_data.m_blue_b = b;
		}

		// 4433
		void set_trans_low_color(uint32_t r, uint32_t g, uint32_t b, uint32_t a)
		{
			assert((r < 16) && (g < 16) && (b < 8) && (a < 8));
			m_trans_color_data.m_red_a = r;
			m_trans_color_data.m_green_a = g;
			m_trans_color_data.m_blue_a = b;
			m_trans_color_data.m_alpha_a = a;
		}

		// 4443
		void set_trans_high_color(uint32_t r, uint32_t g, uint32_t b, uint32_t a)
		{
			assert((r < 16) && (g < 16) && (b < 16) && (a < 8));
			m_trans_color_data.m_red_b = r;
			m_trans_color_data.m_green_b = g;
			m_trans_color_data.m_blue_b = b;
			m_trans_color_data.m_alpha_b = a;
		}
	};

	static struct
	{
		uint8_t m_l, m_h;
	} g_pvrtc2_trans_match34[256];

	static struct
	{
		uint8_t m_l, m_h;
	} g_pvrtc2_trans_match44[256];
		
	static struct
	{
		uint8_t m_l, m_h;
	} g_pvrtc2_alpha_match33[256];
	
	static struct
	{
		uint8_t m_l, m_h;
	} g_pvrtc2_alpha_match33_0[256];

	static struct
	{
		uint8_t m_l, m_h;
	} g_pvrtc2_alpha_match33_3[256];
		
	// PVRTC2 can be forced to look like a slightly weaker variant of ATC/BC1, so that's what we do here for simplicity.
	static void convert_etc1s_to_pvrtc2_rgb(void* pDst, const endpoint* pEndpoints, const selector* pSelector)
	{
		pvrtc2_block* pBlock = static_cast<pvrtc2_block*>(pDst);

		pBlock->m_opaque_color_data.m_hard_flag = 1;
		pBlock->m_opaque_color_data.m_mod_flag = 0;
		pBlock->m_opaque_color_data.m_opaque_flag = 1;

		const uint32_t low_selector = pSelector->m_lo_selector;
		const uint32_t high_selector = pSelector->m_hi_selector;

		const color32& base_color = pEndpoints->m_color5;
		const uint32_t inten_table = pEndpoints->m_inten5;

		if (low_selector == high_selector)
		{
			uint32_t r, g, b;
			decoder_etc_block::get_block_color5(base_color, inten_table, low_selector, r, g, b);

			pBlock->set_low_color(g_atc_match55_equals_1[r].m_lo, g_atc_match55_equals_1[g].m_lo, g_pvrtc2_match45_equals_1[b].m_lo);
			pBlock->set_high_color(g_atc_match55_equals_1[r].m_hi, g_atc_match55_equals_1[g].m_hi, g_pvrtc2_match45_equals_1[b].m_hi);

			pBlock->m_modulation[0] = 0x55;
			pBlock->m_modulation[1] = 0x55;
			pBlock->m_modulation[2] = 0x55;
			pBlock->m_modulation[3] = 0x55;

			return;
		}
		else if ((inten_table >= 7) && (pSelector->m_num_unique_selectors == 2) && (pSelector->m_lo_selector == 0) && (pSelector->m_hi_selector == 3))
		{
			color32 block_colors[4];
			decoder_etc_block::get_block_colors5(block_colors, base_color, inten_table);

			const uint32_t r0 = block_colors[0].r;
			const uint32_t g0 = block_colors[0].g;
			const uint32_t b0 = block_colors[0].b;

			const uint32_t r1 = block_colors[3].r;
			const uint32_t g1 = block_colors[3].g;
			const uint32_t b1 = block_colors[3].b;

			pBlock->set_low_color(g_atc_match5[r0].m_hi, g_atc_match5[g0].m_hi, g_pvrtc2_match4[b0].m_hi);
			pBlock->set_high_color(g_atc_match5[r1].m_hi, g_atc_match5[g1].m_hi, g_atc_match5[b1].m_hi);

			pBlock->m_modulation[0] = pSelector->m_selectors[0];
			pBlock->m_modulation[1] = pSelector->m_selectors[1];
			pBlock->m_modulation[2] = pSelector->m_selectors[2];
			pBlock->m_modulation[3] = pSelector->m_selectors[3];

			return;
		}

		const uint32_t selector_range_table = g_etc1s_to_atc_selector_range_index[low_selector][high_selector];

		//[32][8][RANGES][MAPPING]
		const etc1s_to_atc_solution* pTable_r = &g_etc1s_to_atc_55[(inten_table * 32 + base_color.r) * (NUM_ETC1S_TO_ATC_SELECTOR_RANGES * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS];
		const etc1s_to_atc_solution* pTable_g = &g_etc1s_to_atc_55[(inten_table * 32 + base_color.g) * (NUM_ETC1S_TO_ATC_SELECTOR_RANGES * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS];
		const etc1s_to_atc_solution* pTable_b = &g_etc1s_to_pvrtc2_45[(inten_table * 32 + base_color.b) * (NUM_ETC1S_TO_ATC_SELECTOR_RANGES * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS];

		uint32_t best_err = UINT_MAX;
		uint32_t best_mapping = 0;

		assert(NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS == 10);
#define DO_ITER(m) { uint32_t total_err = pTable_r[m].m_err + pTable_g[m].m_err + pTable_b[m].m_err; if (total_err < best_err) { best_err = total_err; best_mapping = m; } }
		DO_ITER(0); DO_ITER(1); DO_ITER(2); DO_ITER(3); DO_ITER(4);
		DO_ITER(5); DO_ITER(6); DO_ITER(7); DO_ITER(8); DO_ITER(9);
#undef DO_ITER

		pBlock->set_low_color(pTable_r[best_mapping].m_lo, pTable_g[best_mapping].m_lo, pTable_b[best_mapping].m_lo);
		pBlock->set_high_color(pTable_r[best_mapping].m_hi, pTable_g[best_mapping].m_hi, pTable_b[best_mapping].m_hi);

		if (ATC_IDENTITY_SELECTOR_MAPPING_INDEX == best_mapping)
		{
			pBlock->m_modulation[0] = pSelector->m_selectors[0];
			pBlock->m_modulation[1] = pSelector->m_selectors[1];
			pBlock->m_modulation[2] = pSelector->m_selectors[2];
			pBlock->m_modulation[3] = pSelector->m_selectors[3];
		}
		else
		{
			// TODO: We could make this faster using several precomputed 256 entry tables, like ETC1S->BC1 does.
			const uint8_t* pSelectors_xlat = &g_etc1s_to_atc_selector_mappings[best_mapping][0];

			const uint32_t sel_bits0 = pSelector->m_selectors[0];
			const uint32_t sel_bits1 = pSelector->m_selectors[1];
			const uint32_t sel_bits2 = pSelector->m_selectors[2];
			const uint32_t sel_bits3 = pSelector->m_selectors[3];

			uint32_t sels0 = 0, sels1 = 0, sels2 = 0, sels3 = 0;

#define DO_X(x) { \
			const uint32_t x_shift = (x) * 2; \
			sels0 |= (pSelectors_xlat[(sel_bits0 >> x_shift) & 3] << x_shift); \
			sels1 |= (pSelectors_xlat[(sel_bits1 >> x_shift) & 3] << x_shift); \
			sels2 |= (pSelectors_xlat[(sel_bits2 >> x_shift) & 3] << x_shift); \
			sels3 |= (pSelectors_xlat[(sel_bits3 >> x_shift) & 3] << x_shift); }

			DO_X(0);
			DO_X(1);
			DO_X(2);
			DO_X(3);
#undef DO_X

			pBlock->m_modulation[0] = (uint8_t)sels0;
			pBlock->m_modulation[1] = (uint8_t)sels1;
			pBlock->m_modulation[2] = (uint8_t)sels2;
			pBlock->m_modulation[3] = (uint8_t)sels3;
		}
	}
				
	static inline vec4F* vec4F_set_scalar(vec4F* pV, float x) { pV->c[0] = x; pV->c[1] = x; pV->c[2] = x;	pV->c[3] = x;	return pV; }
	static inline vec4F* vec4F_set(vec4F* pV, float x, float y, float z, float w) { pV->c[0] = x;	pV->c[1] = y;	pV->c[2] = z;	pV->c[3] = w;	return pV; }
	static inline vec4F* vec4F_saturate_in_place(vec4F* pV) { pV->c[0] = saturate(pV->c[0]); pV->c[1] = saturate(pV->c[1]); pV->c[2] = saturate(pV->c[2]); pV->c[3] = saturate(pV->c[3]); return pV; }
	static inline vec4F vec4F_saturate(const vec4F* pV) { vec4F res; res.c[0] = saturate(pV->c[0]); res.c[1] = saturate(pV->c[1]); res.c[2] = saturate(pV->c[2]); res.c[3] = saturate(pV->c[3]); return res; }
	static inline vec4F vec4F_from_color(const color32* pC) { vec4F res; vec4F_set(&res, pC->c[0], pC->c[1], pC->c[2], pC->c[3]); return res; }
	static inline vec4F vec4F_add(const vec4F* pLHS, const vec4F* pRHS) { vec4F res; vec4F_set(&res, pLHS->c[0] + pRHS->c[0], pLHS->c[1] + pRHS->c[1], pLHS->c[2] + pRHS->c[2], pLHS->c[3] + pRHS->c[3]); return res; }
	static inline vec4F vec4F_sub(const vec4F* pLHS, const vec4F* pRHS) { vec4F res; vec4F_set(&res, pLHS->c[0] - pRHS->c[0], pLHS->c[1] - pRHS->c[1], pLHS->c[2] - pRHS->c[2], pLHS->c[3] - pRHS->c[3]); return res; }
	static inline float vec4F_dot(const vec4F* pLHS, const vec4F* pRHS) { return pLHS->c[0] * pRHS->c[0] + pLHS->c[1] * pRHS->c[1] + pLHS->c[2] * pRHS->c[2] + pLHS->c[3] * pRHS->c[3]; }
	static inline vec4F vec4F_mul(const vec4F* pLHS, float s) { vec4F res; vec4F_set(&res, pLHS->c[0] * s, pLHS->c[1] * s, pLHS->c[2] * s, pLHS->c[3] * s); return res; }
	static inline vec4F* vec4F_normalize_in_place(vec4F* pV) { float s = pV->c[0] * pV->c[0] + pV->c[1] * pV->c[1] + pV->c[2] * pV->c[2] + pV->c[3] * pV->c[3]; if (s != 0.0f) { s = 1.0f / sqrtf(s); pV->c[0] *= s; pV->c[1] *= s; pV->c[2] *= s; pV->c[3] *= s; } return pV; }

	static color32 convert_rgba_5554_to_8888(const color32& col)
	{
		return color32((col[0] << 3) | (col[0] >> 2), (col[1] << 3) | (col[1] >> 2), (col[2] << 3) | (col[2] >> 2), (col[3] << 4) | col[3]);
	}

	static inline int sq(int x) { return x * x; }
						
	// PVRTC2 is a slightly borked format for alpha: In Non-Interpolated mode, the way AlphaB8 is expanded from 4 to 8 bits means it can never be 0. 
	// This is actually very bad, because on 100% transparent blocks which have non-trivial color pixels, part of the color channel will leak into alpha! 
	// And there's nothing straightforward we can do because using the other modes is too expensive/complex. I can see why Apple didn't adopt it.
	static void convert_etc1s_to_pvrtc2_rgba(void* pDst, const endpoint* pEndpoints, const selector* pSelector, const endpoint* pEndpoint_codebook, const selector* pSelector_codebook)
	{
		pvrtc2_block* pBlock = static_cast<pvrtc2_block*>(pDst);

		const endpoint& alpha_endpoint = pEndpoint_codebook[((uint16_t*)pBlock)[0]];
		const selector& alpha_selectors = pSelector_codebook[((uint16_t*)pBlock)[1]];

		pBlock->m_opaque_color_data.m_hard_flag = 1;
		pBlock->m_opaque_color_data.m_mod_flag = 0;
		pBlock->m_opaque_color_data.m_opaque_flag = 0;

		const int num_unique_alpha_selectors = alpha_selectors.m_num_unique_selectors;

		const color32& alpha_base_color = alpha_endpoint.m_color5;
		const uint32_t alpha_inten_table = alpha_endpoint.m_inten5;

		int constant_alpha_val = -1;

		int alpha_block_colors[4];
		decoder_etc_block::get_block_colors5_g(alpha_block_colors, alpha_base_color, alpha_inten_table);

		if (num_unique_alpha_selectors == 1)
		{
			constant_alpha_val = alpha_block_colors[alpha_selectors.m_lo_selector];
		}
		else
		{
			constant_alpha_val = alpha_block_colors[alpha_selectors.m_lo_selector];

			for (uint32_t i = alpha_selectors.m_lo_selector + 1; i <= alpha_selectors.m_hi_selector; i++)
			{
				if (constant_alpha_val != alpha_block_colors[i])
				{
					constant_alpha_val = -1;
					break;
				}
			}
		}

		if (constant_alpha_val >= 250)
		{
			// It's opaque enough, so don't bother trying to encode it as an alpha block.
			convert_etc1s_to_pvrtc2_rgb(pDst, pEndpoints, pSelector);
			return;
		}

		const color32& base_color = pEndpoints->m_color5;
		const uint32_t inten_table = pEndpoints->m_inten5;

		const uint32_t low_selector = pSelector->m_lo_selector;
		const uint32_t high_selector = pSelector->m_hi_selector;

		const int num_unique_color_selectors = pSelector->m_num_unique_selectors;
				
		// We need to reencode the block at the pixel level, unfortunately, from two ETC1S planes.
		// Do 4D incremental PCA, project all pixels to this hyperline, then quantize to packed endpoints and compute the modulation values.
		const int br = (base_color.r << 3) | (base_color.r >> 2);
		const int bg = (base_color.g << 3) | (base_color.g >> 2);
		const int bb = (base_color.b << 3) | (base_color.b >> 2);
		
		color32 block_cols[4];
		for (uint32_t i = 0; i < 4; i++)
		{
			const int ci = g_etc1_inten_tables[inten_table][i];
			block_cols[i].set_clamped(br + ci, bg + ci, bb + ci, alpha_block_colors[i]);
		}

		bool solid_color_block = true;
		if (num_unique_color_selectors > 1)
		{
			for (uint32_t i = low_selector + 1; i <= high_selector; i++)
			{
				if ((block_cols[low_selector].r != block_cols[i].r) || (block_cols[low_selector].g != block_cols[i].g) || (block_cols[low_selector].b != block_cols[i].b))
				{
					solid_color_block = false;
					break;
				}
			}
		}

		if ((solid_color_block) && (constant_alpha_val >= 0))
		{
			// Constant color/alpha block.
			// This is more complex than it may seem because of the way color and alpha are packed in PVRTC2. We need to evaluate mod0, mod1 and mod3 encodings to find the best one.
			uint32_t r, g, b;
			decoder_etc_block::get_block_color5(base_color, inten_table, low_selector, r, g, b);

			// Mod 0
			uint32_t lr0 = (r * 15 + 128) / 255, lg0 = (g * 15 + 128) / 255, lb0 = (b * 7 + 128) / 255; 
			uint32_t la0 = g_pvrtc2_alpha_match33_0[constant_alpha_val].m_l;

			uint32_t cr0 = (lr0 << 1) | (lr0 >> 3);
			uint32_t cg0 = (lg0 << 1) | (lg0 >> 3);
			uint32_t cb0 = (lb0 << 2) | (lb0 >> 1);
			uint32_t ca0 = (la0 << 1);
			
			cr0 = (cr0 << 3) | (cr0 >> 2);
			cg0 = (cg0 << 3) | (cg0 >> 2);
			cb0 = (cb0 << 3) | (cb0 >> 2);
			ca0 = (ca0 << 4) | ca0;

			uint32_t err0 = sq(cr0 - r) + sq(cg0 - g) + sq(cb0 - b) + sq(ca0 - constant_alpha_val) * 2;

			// If the alpha is < 3 or so we're kinda screwed. It's better to have some RGB error than it is to turn a 100% transparent area slightly opaque.
			if ((err0 == 0) || (constant_alpha_val < 3))
			{
				pBlock->set_trans_low_color(lr0, lg0, lb0, la0);
				pBlock->set_trans_high_color(0, 0, 0, 0);

				pBlock->m_modulation[0] = 0;
				pBlock->m_modulation[1] = 0;
				pBlock->m_modulation[2] = 0;
				pBlock->m_modulation[3] = 0;
				return;
			}

			// Mod 3
			uint32_t lr3 = (r * 15 + 128) / 255, lg3 = (g * 15 + 128) / 255, lb3 = (b * 15 + 128) / 255;
			uint32_t la3 = g_pvrtc2_alpha_match33_3[constant_alpha_val].m_l;

			uint32_t cr3 = (lr3 << 1) | (lr3 >> 3);
			uint32_t cg3 = (lg3 << 1) | (lg3 >> 3);
			uint32_t cb3 = (lb3 << 1) | (lb3 >> 3);
			uint32_t ca3 = (la3 << 1) | 1;
			
			cr3 = (cr3 << 3) | (cr3 >> 2);
			cg3 = (cg3 << 3) | (cg3 >> 2);
			cb3 = (cb3 << 3) | (cb3 >> 2);
			ca3 = (ca3 << 4) | ca3;

			uint32_t err3 = sq(cr3 - r) + sq(cg3 - g) + sq(cb3 - b) + sq(ca3 - constant_alpha_val) * 2;
			
			// Mod 1
			uint32_t lr1 = g_pvrtc2_trans_match44[r].m_l, lg1 = g_pvrtc2_trans_match44[g].m_l, lb1 = g_pvrtc2_trans_match34[b].m_l;
			uint32_t hr1 = g_pvrtc2_trans_match44[r].m_h, hg1 = g_pvrtc2_trans_match44[g].m_h, hb1 = g_pvrtc2_trans_match34[b].m_h;
			uint32_t la1 = g_pvrtc2_alpha_match33[constant_alpha_val].m_l, ha1 = g_pvrtc2_alpha_match33[constant_alpha_val].m_h;

			uint32_t clr1 = (lr1 << 1) | (lr1 >> 3);
			uint32_t clg1 = (lg1 << 1) | (lg1 >> 3);
			uint32_t clb1 = (lb1 << 2) | (lb1 >> 1);
			uint32_t cla1 = (la1 << 1);

			clr1 = (clr1 << 3) | (clr1 >> 2);
			clg1 = (clg1 << 3) | (clg1 >> 2);
			clb1 = (clb1 << 3) | (clb1 >> 2);
			cla1 = (cla1 << 4) | cla1;

			uint32_t chr1 = (hr1 << 1) | (hr1 >> 3);
			uint32_t chg1 = (hg1 << 1) | (hg1 >> 3);
			uint32_t chb1 = (hb1 << 1) | (hb1 >> 3);
			uint32_t cha1 = (ha1 << 1) | 1;

			chr1 = (chr1 << 3) | (chr1 >> 2);
			chg1 = (chg1 << 3) | (chg1 >> 2);
			chb1 = (chb1 << 3) | (chb1 >> 2);
			cha1 = (cha1 << 4) | cha1;

			uint32_t r1 = (clr1 * 5 + chr1 * 3) / 8;
			uint32_t g1 = (clg1 * 5 + chg1 * 3) / 8;
			uint32_t b1 = (clb1 * 5 + chb1 * 3) / 8;
			uint32_t a1 = (cla1 * 5 + cha1 * 3) / 8;

			uint32_t err1 = sq(r1 - r) + sq(g1 - g) + sq(b1 - b) + sq(a1 - constant_alpha_val) * 2;

			if ((err1 < err0) && (err1 < err3))
			{
				pBlock->set_trans_low_color(lr1, lg1, lb1, la1);
				pBlock->set_trans_high_color(hr1, hg1, hb1, ha1);

				pBlock->m_modulation[0] = 0x55;
				pBlock->m_modulation[1] = 0x55;
				pBlock->m_modulation[2] = 0x55;
				pBlock->m_modulation[3] = 0x55;
			}
			else if (err0 < err3)
			{
				pBlock->set_trans_low_color(lr0, lg0, lb0, la0);
				pBlock->set_trans_high_color(0, 0, 0, 0);

				pBlock->m_modulation[0] = 0;
				pBlock->m_modulation[1] = 0;
				pBlock->m_modulation[2] = 0;
				pBlock->m_modulation[3] = 0;
			}
			else
			{
				pBlock->set_trans_low_color(0, 0, 0, 0);
				pBlock->set_trans_high_color(lr3, lg3, lb3, la3);

				pBlock->m_modulation[0] = 0xFF;
				pBlock->m_modulation[1] = 0xFF;
				pBlock->m_modulation[2] = 0xFF;
				pBlock->m_modulation[3] = 0xFF;
			}

			return;
		}

		// It's a complex block with non-solid color and/or alpha pixels.
		vec4F minColor, maxColor;

		if (solid_color_block)
		{
			// It's a solid color block.
			uint32_t low_a = block_cols[alpha_selectors.m_lo_selector].a;
			uint32_t high_a = block_cols[alpha_selectors.m_hi_selector].a;
			
			const float S = 1.0f / 255.0f;
			vec4F_set(&minColor, block_cols[low_selector].r * S, block_cols[low_selector].g * S, block_cols[low_selector].b * S, low_a * S);
			vec4F_set(&maxColor, block_cols[low_selector].r * S, block_cols[low_selector].g * S, block_cols[low_selector].b * S, high_a * S);
		}
		else if (constant_alpha_val >= 0)
		{
			// It's a solid alpha block.
			const float S = 1.0f / 255.0f;
			vec4F_set(&minColor, block_cols[low_selector].r * S, block_cols[low_selector].g * S, block_cols[low_selector].b * S, constant_alpha_val * S);
			vec4F_set(&maxColor, block_cols[high_selector].r * S, block_cols[high_selector].g * S, block_cols[high_selector].b * S, constant_alpha_val * S);
	   }
		// See if any of the block colors got clamped - if so the principle axis got distorted (it's no longer just the ETC1S luma axis). 
		// To keep quality up we need to use full 4D PCA in this case.
		else if ((block_cols[low_selector].c[0] == 0) || (block_cols[high_selector].c[0] == 255) ||
				(block_cols[low_selector].c[1] == 0) || (block_cols[high_selector].c[1] == 255) ||
				(block_cols[low_selector].c[2] == 0) || (block_cols[high_selector].c[2] == 255) ||
				(block_cols[alpha_selectors.m_lo_selector].c[3] == 0) || (block_cols[alpha_selectors.m_hi_selector].c[3] == 255))
		{
			// Find principle component of RGBA colors treated as 4D vectors.
			color32 pixels[16];

			uint32_t sum_r = 0, sum_g = 0, sum_b = 0, sum_a = 0;
			for (uint32_t i = 0; i < 16; i++)
			{
				color32 rgb(block_cols[pSelector->get_selector(i & 3, i >> 2)]);
				uint32_t a = block_cols[alpha_selectors.get_selector(i & 3, i >> 2)].a;

				pixels[i].set(rgb.r, rgb.g, rgb.b, a);

				sum_r += rgb.r;
				sum_g += rgb.g;
				sum_b += rgb.b;
				sum_a += a;
			}

			vec4F meanColor;
			vec4F_set(&meanColor, (float)sum_r, (float)sum_g, (float)sum_b, (float)sum_a);
			vec4F meanColorScaled = vec4F_mul(&meanColor, 1.0f / 16.0f);

			meanColor = vec4F_mul(&meanColor, 1.0f / (float)(16.0f * 255.0f));
			vec4F_saturate_in_place(&meanColor);

			vec4F axis;
			vec4F_set_scalar(&axis, 0.0f);
			// Why this incremental method? Because it's stable and predictable. Covar+power method can require a lot of iterations to converge in 4D.
			for (uint32_t i = 0; i < 16; i++)
			{
				vec4F color = vec4F_from_color(&pixels[i]);
				color = vec4F_sub(&color, &meanColorScaled);
				vec4F a = vec4F_mul(&color, color.c[0]);
				vec4F b = vec4F_mul(&color, color.c[1]);
				vec4F c = vec4F_mul(&color, color.c[2]);
				vec4F d = vec4F_mul(&color, color.c[3]);
				vec4F n = i ? axis : color;
				vec4F_normalize_in_place(&n);
				axis.c[0] += vec4F_dot(&a, &n);
				axis.c[1] += vec4F_dot(&b, &n);
				axis.c[2] += vec4F_dot(&c, &n);
				axis.c[3] += vec4F_dot(&d, &n);
			}

			vec4F_normalize_in_place(&axis);
						
			if (vec4F_dot(&axis, &axis) < .5f)
				vec4F_set_scalar(&axis, .5f);

			float l = 1e+9f, h = -1e+9f;

			for (uint32_t i = 0; i < 16; i++)
			{
				vec4F color = vec4F_from_color(&pixels[i]);

				vec4F q = vec4F_sub(&color, &meanColorScaled);
				float d = vec4F_dot(&q, &axis);

				l = basisu::minimum(l, d);
				h = basisu::maximum(h, d);
			}

			l *= (1.0f / 255.0f);
			h *= (1.0f / 255.0f);

			vec4F b0 = vec4F_mul(&axis, l);
			vec4F b1 = vec4F_mul(&axis, h);
			vec4F c0 = vec4F_add(&meanColor, &b0);
			vec4F c1 = vec4F_add(&meanColor, &b1);
			minColor = vec4F_saturate(&c0);
			maxColor = vec4F_saturate(&c1);
			if (minColor.c[3] > maxColor.c[3])
			{
				// VS 2019 release Code Generator issue
				//std::swap(minColor, maxColor);

				float a = minColor.c[0], b = minColor.c[1], c = minColor.c[2], d = minColor.c[3];
				minColor.c[0] = maxColor.c[0]; minColor.c[1] = maxColor.c[1]; minColor.c[2] = maxColor.c[2]; minColor.c[3] = maxColor.c[3];
				minColor.c[0] = maxColor.c[0]; minColor.c[1] = maxColor.c[1]; minColor.c[2] = maxColor.c[2]; minColor.c[3] = maxColor.c[3];
				maxColor.c[0] = a; maxColor.c[1] = b; maxColor.c[2] = c; maxColor.c[3] = d;
			}
		}
		else
		{
			// We know the RGB axis is luma, because it's an ETC1S block and none of the block colors got clamped. So we only need to use 2D PCA.
			// We project each LA vector onto two 2D lines with axes (1,1) and (1,-1) and find the largest projection to determine if axis A is flipped relative to L.
			uint32_t block_cols_l[4], block_cols_a[4];
			for (uint32_t i = 0; i < 4; i++)
			{
				block_cols_l[i] = block_cols[i].r + block_cols[i].g + block_cols[i].b;
				block_cols_a[i] = block_cols[i].a * 3;
			}

			int p0_min = INT_MAX, p0_max = INT_MIN;
			int p1_min = INT_MAX, p1_max = INT_MIN;
			for (uint32_t y = 0; y < 4; y++)
			{
				const uint32_t cs = pSelector->m_selectors[y];
				const uint32_t as = alpha_selectors.m_selectors[y];

				{
					const int l = block_cols_l[cs & 3];
					const int a = block_cols_a[as & 3];
					const int p0 = l + a; p0_min = basisu::minimum(p0_min, p0); p0_max = basisu::maximum(p0_max, p0);
					const int p1 = l - a; p1_min = basisu::minimum(p1_min, p1); p1_max = basisu::maximum(p1_max, p1);
				}
				{
					const int l = block_cols_l[(cs >> 2) & 3];
					const int a = block_cols_a[(as >> 2) & 3];
					const int p0 = l + a; p0_min = basisu::minimum(p0_min, p0); p0_max = basisu::maximum(p0_max, p0);
					const int p1 = l - a; p1_min = basisu::minimum(p1_min, p1); p1_max = basisu::maximum(p1_max, p1);
				}
				{
					const int l = block_cols_l[(cs >> 4) & 3];
					const int a = block_cols_a[(as >> 4) & 3];
					const int p0 = l + a; p0_min = basisu::minimum(p0_min, p0); p0_max = basisu::maximum(p0_max, p0);
					const int p1 = l - a; p1_min = basisu::minimum(p1_min, p1); p1_max = basisu::maximum(p1_max, p1);
				}
				{
					const int l = block_cols_l[cs >> 6];
					const int a = block_cols_a[as >> 6];
					const int p0 = l + a; p0_min = basisu::minimum(p0_min, p0); p0_max = basisu::maximum(p0_max, p0);
					const int p1 = l - a; p1_min = basisu::minimum(p1_min, p1); p1_max = basisu::maximum(p1_max, p1);
				}
			}

			int dist0 = p0_max - p0_min;
			int dist1 = p1_max - p1_min;

			const float S = 1.0f / 255.0f;

			vec4F_set(&minColor, block_cols[low_selector].r * S, block_cols[low_selector].g * S, block_cols[low_selector].b * S, block_cols[alpha_selectors.m_lo_selector].a * S);
			vec4F_set(&maxColor, block_cols[high_selector].r * S, block_cols[high_selector].g * S, block_cols[high_selector].b * S, block_cols[alpha_selectors.m_hi_selector].a * S);

			// See if the A component of the principle axis is flipped relative to L. If so, we need to flip either RGB or A bounds.
			if (dist1 > dist0)
			{
				std::swap(minColor.c[0], maxColor.c[0]);
				std::swap(minColor.c[1], maxColor.c[1]);
				std::swap(minColor.c[2], maxColor.c[2]);
			}
		}

		// 4433 4443
		color32 trialMinColor, trialMaxColor;
				
		trialMinColor.set_clamped((int)(minColor.c[0] * 15.0f + .5f), (int)(minColor.c[1] * 15.0f + .5f), (int)(minColor.c[2] * 7.0f + .5f), (int)(minColor.c[3] * 7.0f + .5f));
		trialMaxColor.set_clamped((int)(maxColor.c[0] * 15.0f + .5f), (int)(maxColor.c[1] * 15.0f + .5f), (int)(maxColor.c[2] * 15.0f + .5f), (int)(maxColor.c[3] * 7.0f + .5f));
				
		pBlock->set_trans_low_color(trialMinColor.r, trialMinColor.g, trialMinColor.b, trialMinColor.a);
		pBlock->set_trans_high_color(trialMaxColor.r, trialMaxColor.g, trialMaxColor.b, trialMaxColor.a);

		color32 color_a((trialMinColor.r << 1) | (trialMinColor.r >> 3), (trialMinColor.g << 1) | (trialMinColor.g >> 3), (trialMinColor.b << 2) | (trialMinColor.b >> 1), trialMinColor.a << 1);
		color32 color_b((trialMaxColor.r << 1) | (trialMaxColor.r >> 3), (trialMaxColor.g << 1) | (trialMaxColor.g >> 3), (trialMaxColor.b << 1) | (trialMaxColor.b >> 3), (trialMaxColor.a << 1) | 1);

		color32 color0(convert_rgba_5554_to_8888(color_a));
		color32 color3(convert_rgba_5554_to_8888(color_b));

		const int lr = color0.r;
		const int lg = color0.g;
		const int lb = color0.b;
		const int la = color0.a;

		const int axis_r = color3.r - lr;
		const int axis_g = color3.g - lg;
		const int axis_b = color3.b - lb;
		const int axis_a = color3.a - la;
		const int len_a = (axis_r * axis_r) + (axis_g * axis_g) + (axis_b * axis_b) + (axis_a * axis_a);

		const int thresh01 = (len_a * 3) / 16;
		const int thresh12 = len_a >> 1;
		const int thresh23 = (len_a * 13) / 16;

		if ((axis_r | axis_g | axis_b) == 0)
		{
			int ca_sel[4];

			for (uint32_t i = 0; i < 4; i++)
			{
				int ca = (block_cols[i].a - la) * axis_a;
				ca_sel[i] = (ca >= thresh23) + (ca >= thresh12) + (ca >= thresh01);
			}

			for (uint32_t y = 0; y < 4; y++)
			{
				const uint32_t a_sels = alpha_selectors.m_selectors[y];

				uint32_t sel = ca_sel[a_sels & 3] | (ca_sel[(a_sels >> 2) & 3] << 2) | (ca_sel[(a_sels >> 4) & 3] << 4) | (ca_sel[a_sels >> 6] << 6);

				pBlock->m_modulation[y] = (uint8_t)sel;
			}
		}
		else
		{
			int cy[4], ca[4];

			for (uint32_t i = 0; i < 4; i++)
			{
				cy[i] = (block_cols[i].r - lr) * axis_r + (block_cols[i].g - lg) * axis_g + (block_cols[i].b - lb) * axis_b;
				ca[i] = (block_cols[i].a - la) * axis_a;
			}

			for (uint32_t y = 0; y < 4; y++)
			{
				const uint32_t c_sels = pSelector->m_selectors[y];
				const uint32_t a_sels = alpha_selectors.m_selectors[y];

				const int d0 = cy[c_sels & 3] + ca[a_sels & 3];
				const int d1 = cy[(c_sels >> 2) & 3] + ca[(a_sels >> 2) & 3];
				const int d2 = cy[(c_sels >> 4) & 3] + ca[(a_sels >> 4) & 3];
				const int d3 = cy[c_sels >> 6] + ca[a_sels >> 6];

				uint32_t sel = ((d0 >= thresh23) + (d0 >= thresh12) + (d0 >= thresh01)) |
					(((d1 >= thresh23) + (d1 >= thresh12) + (d1 >= thresh01)) << 2) |
					(((d2 >= thresh23) + (d2 >= thresh12) + (d2 >= thresh01)) << 4) |
					(((d3 >= thresh23) + (d3 >= thresh12) + (d3 >= thresh01)) << 6);

				pBlock->m_modulation[y] = (uint8_t)sel;
			}
		}
	}
		
	static void transcoder_init_pvrtc2()
	{
		for (uint32_t v = 0; v < 256; v++)
		{
			int best_l = 0, best_h = 0, lowest_err = INT_MAX;

			for (uint32_t l = 0; l < 8; l++)
			{
				uint32_t le = (l << 1);
				le = (le << 4) | le;

				for (uint32_t h = 0; h < 8; h++)
				{
					uint32_t he = (h << 1) | 1;
					he = (he << 4) | he;

					uint32_t m = (le * 5 + he * 3) / 8;

					int err = (int)labs((int)v - (int)m);
					if (err < lowest_err)
					{
						lowest_err = err;
						best_l = l;
						best_h = h;
					}
				}
			}

			g_pvrtc2_alpha_match33[v].m_l = (uint8_t)best_l;
			g_pvrtc2_alpha_match33[v].m_h = (uint8_t)best_h;
		}

		for (uint32_t v = 0; v < 256; v++)
		{
			int best_l = 0, best_h = 0, lowest_err = INT_MAX;

			for (uint32_t l = 0; l < 8; l++)
			{
				uint32_t le = (l << 1);
				le = (le << 4) | le;

				int err = (int)labs((int)v - (int)le);
				if (err < lowest_err)
				{
					lowest_err = err;
					best_l = l;
					best_h = l;
				}
			}

			g_pvrtc2_alpha_match33_0[v].m_l = (uint8_t)best_l;
			g_pvrtc2_alpha_match33_0[v].m_h = (uint8_t)best_h;
		}

		for (uint32_t v = 0; v < 256; v++)
		{
			int best_l = 0, best_h = 0, lowest_err = INT_MAX;

			for (uint32_t h = 0; h < 8; h++)
			{
				uint32_t he = (h << 1) | 1;
				he = (he << 4) | he;

				int err = (int)labs((int)v - (int)he);
				if (err < lowest_err)
				{
					lowest_err = err;
					best_l = h;
					best_h = h;
				}
			}

			g_pvrtc2_alpha_match33_3[v].m_l = (uint8_t)best_l;
			g_pvrtc2_alpha_match33_3[v].m_h = (uint8_t)best_h;
		}

		for (uint32_t v = 0; v < 256; v++)
		{
			int best_l = 0, best_h = 0, lowest_err = INT_MAX;

			for (uint32_t l = 0; l < 8; l++)
			{
				uint32_t le = (l << 2) | (l >> 1);
				le = (le << 3) | (le >> 2);

				for (uint32_t h = 0; h < 16; h++)
				{
					uint32_t he = (h << 1) | (h >> 3);
					he = (he << 3) | (he >> 2);

					uint32_t m = (le * 5 + he * 3) / 8;

					int err = (int)labs((int)v - (int)m);
					if (err < lowest_err)
					{
						lowest_err = err;
						best_l = l;
						best_h = h;
					}
				}
			}

			g_pvrtc2_trans_match34[v].m_l = (uint8_t)best_l;
			g_pvrtc2_trans_match34[v].m_h = (uint8_t)best_h;
		}
				
		for (uint32_t v = 0; v < 256; v++)
		{
			int best_l = 0, best_h = 0, lowest_err = INT_MAX;

			for (uint32_t l = 0; l < 16; l++)
			{
				uint32_t le = (l << 1) | (l >> 3);
				le = (le << 3) | (le >> 2);

				for (uint32_t h = 0; h < 16; h++)
				{
					uint32_t he = (h << 1) | (h >> 3);
					he = (he << 3) | (he >> 2);

					uint32_t m = (le * 5 + he * 3) / 8;

					int err = (int)labs((int)v - (int)m);
					if (err < lowest_err)
					{
						lowest_err = err;
						best_l = l;
						best_h = h;
					}
				}
			}

			g_pvrtc2_trans_match44[v].m_l = (uint8_t)best_l;
			g_pvrtc2_trans_match44[v].m_h = (uint8_t)best_h;
		}
	}
#endif // BASISD_SUPPORT_PVRTC2

	//------------------------------------------------------------------------------------------------
	
	// BC7 mode 5 RGB encoder

#if BASISD_SUPPORT_BC7_MODE5
	namespace bc7_mode_5_encoder
	{		
		static float g_mode5_rgba_midpoints[128];

		void encode_bc7_mode5_init()
		{
			// Mode 5 endpoint midpoints
			for (uint32_t i = 0; i < 128; i++)
			{
				uint32_t vl = (i << 1);
				vl |= (vl >> 7);
				float lo = vl / 255.0f;

				uint32_t vh = basisu::minimumi(127, i + 1) << 1;
				vh |= (vh >> 7);
				float hi = vh / 255.0f;

				if (i == 127)
					g_mode5_rgba_midpoints[i] = 1e+15f;
				else
					g_mode5_rgba_midpoints[i] = (lo + hi) / 2.0f;
			}
		}

		static inline uint32_t from_7(uint32_t v)
		{
			assert(v < 128);
			return (v << 1) | (v >> 6);
		}

		static inline int to_7(float c)
		{
			assert((c >= 0) && (c <= 1.0f));

			int vl = (int)(c * 127.0f);
			vl += (c > g_mode5_rgba_midpoints[vl]);
			return clampi(vl, 0, 127);
		}

		static inline int to_7(int c8)
		{
			assert((c8 >= 0) && (c8 <= 255));

			float c = (float)c8 * (1.0f / 255.0f);

			int vl = (int)(c * 127.0f);
			vl += (c > g_mode5_rgba_midpoints[vl]);
			return clampi(vl, 0, 127);
		}

		// This is usable with ASTC as well, which uses the same 2-bit interpolation weights.
		static inline uint32_t bc7_interp2(uint32_t l, uint32_t h, uint32_t w)
		{
			assert(w < 4);
			return (l * (64 - basist::g_bc7_weights2[w]) + h * basist::g_bc7_weights2[w] + 32) >> 6;
		}

		static void eval_weights(
			const color32 *pPixels, uint8_t* pWeights,
			int lr, int lg, int lb,
			int hr, int hg, int hb)
		{
			lr = from_7(lr); lg = from_7(lg); lb = from_7(lb);
			hr = from_7(hr); hg = from_7(hg); hb = from_7(hb);

			int cr[4], cg[4], cb[4];
			for (uint32_t i = 0; i < 4; i++)
			{
				cr[i] = (uint8_t)bc7_interp2(lr, hr, i);
				cg[i] = (uint8_t)bc7_interp2(lg, hg, i);
				cb[i] = (uint8_t)bc7_interp2(lb, hb, i);
			}

#if 0
			for (uint32_t i = 0; i < 16; i++)
			{
				const int pr = pPixels[i].r, pg = pPixels[i].g, pb = pPixels[i].b;

				uint32_t best_err = UINT32_MAX;
				uint32_t best_idx = 0;
				for (uint32_t j = 0; j < 4; j++)
				{
					uint32_t e = square(pr - cr[j]) + square(pg - cg[j]) + square(pb - cb[j]);
					if (e < best_err)
					{
						best_err = e;
						best_idx = j;
					}

					pWeights[i] = (uint8_t)best_idx;
				}
			} // i
#else
			int ar = cr[3] - cr[0], ag = cg[3] - cg[0], ab = cb[3] - cb[0];

			int dots[4];
			for (uint32_t i = 0; i < 4; i++)
				dots[i] = (int)cr[i] * ar + (int)cg[i] * ag + (int)cb[i] * ab;

			// seems very rare in LDR, so rare that it doesn't matter
			//assert(dots[0] <= dots[1]);
			//assert(dots[1] <= dots[2]);
			//assert(dots[2] <= dots[3]);

			int t0 = dots[0] + dots[1], t1 = dots[1] + dots[2], t2 = dots[2] + dots[3];

			ar *= 2; ag *= 2; ab *= 2;

			for (uint32_t i = 0; i < 16; i += 4)
			{
				const int d0 = pPixels[i + 0].r * ar + pPixels[i + 0].g * ag + pPixels[i + 0].b * ab;
				const int d1 = pPixels[i + 1].r * ar + pPixels[i + 1].g * ag + pPixels[i + 1].b * ab;
				const int d2 = pPixels[i + 2].r * ar + pPixels[i + 2].g * ag + pPixels[i + 2].b * ab;
				const int d3 = pPixels[i + 3].r * ar + pPixels[i + 3].g * ag + pPixels[i + 3].b * ab;

				pWeights[i + 0] = (d0 > t0) + (d0 >= t1) + (d0 >= t2);
				pWeights[i + 1] = (d1 > t0) + (d1 >= t1) + (d1 >= t2);
				pWeights[i + 2] = (d2 > t0) + (d2 >= t1) + (d2 >= t2);
				pWeights[i + 3] = (d3 > t0) + (d3 >= t1) + (d3 >= t2);
			}
#endif
		}

		static void pack_bc7_mode5_rgb_block(
			bc7_mode_5* pDst_block,
			int lr, int lg, int lb, int hr, int hg, int hb,
			const uint8_t* pWeights)
		{
			assert((lr >= 0) && (lr <= 127));
			assert((lg >= 0) && (lg <= 127));
			assert((lb >= 0) && (lb <= 127));
			assert((hr >= 0) && (hr <= 127));
			assert((hg >= 0) && (hg <= 127));
			assert((hb >= 0) && (hb <= 127));

			pDst_block->m_lo_bits = 0;

			uint8_t weight_inv = 0;
			if (pWeights[0] & 2)
			{
				std::swap(lr, hr);
				std::swap(lg, hg);
				std::swap(lb, hb);
				weight_inv = 3;
			}
			assert((pWeights[0] ^ weight_inv) <= 1);

			pDst_block->m_lo.m_mode = 32;
			pDst_block->m_lo.m_r0 = lr;
			pDst_block->m_lo.m_r1 = hr;
			pDst_block->m_lo.m_g0 = lg;
			pDst_block->m_lo.m_g1 = hg;
			pDst_block->m_lo.m_b0 = lb;
			pDst_block->m_lo.m_b1 = hb;

			pDst_block->m_lo.m_a0 = 255;
			pDst_block->m_lo.m_a1_0 = 63;

			uint64_t sel_bits = 3;
			uint32_t cur_ofs = 2;
			for (uint32_t i = 0; i < 16; i++)
			{
				assert(pWeights[i] <= 3);
				sel_bits |= ((uint64_t)(weight_inv ^ pWeights[i])) << cur_ofs;
				cur_ofs += (i ? 2 : 1);
			}

			pDst_block->m_hi_bits = sel_bits;
		}

		// This table is: 9 * (w * w), 9 * ((1.0f - w) * w), 9 * ((1.0f - w) * (1.0f - w))
		// where w is [0,1/3,2/3,1]. 9 is the perfect multiplier.
		static const uint32_t g_weight_vals4[4] = { 0x000009, 0x010204, 0x040201, 0x090000 };

		static inline bool compute_least_squares_endpoints4_rgb(
			const color32 *pColors, const uint8_t* pSelectors,
			int& lr, int& lg, int& lb, int& hr, int& hg, int& hb,
			int total_r, int total_g, int total_b)
		{
			uint32_t uq00_r = 0, uq00_g = 0, uq00_b = 0;
			uint32_t weight_accum = 0;
			for (uint32_t i = 0; i < 16; i++)
			{
				const uint8_t r = pColors[i].r, g = pColors[i].g, b = pColors[i].b;
				const uint8_t sel = pSelectors[i];

				weight_accum += g_weight_vals4[sel];
				uq00_r += sel * r;
				uq00_g += sel * g;
				uq00_b += sel * b;
			}

			int q10_r = total_r * 3 - uq00_r;
			int q10_g = total_g * 3 - uq00_g;
			int q10_b = total_b * 3 - uq00_b;

			float z00 = (float)((weight_accum >> 16) & 0xFF);
			float z10 = (float)((weight_accum >> 8) & 0xFF);
			float z11 = (float)(weight_accum & 0xFF);
			float z01 = z10;

			float det = z00 * z11 - z01 * z10;
			if (fabs(det) < 1e-8f)
				return false;

			det = (3.0f / 255.0f) / det;

			float iz00, iz01, iz10, iz11;
			iz00 = z11 * det;
			iz01 = -z01 * det;
			iz10 = -z10 * det;
			iz11 = z00 * det;

			float fhr = basisu::clamp(iz00 * (float)uq00_r + iz01 * q10_r, 0.0f, 1.0f);
			float flr = basisu::clamp(iz10 * (float)uq00_r + iz11 * q10_r, 0.0f, 1.0f);

			float fhg = basisu::clamp(iz00 * (float)uq00_g + iz01 * q10_g, 0.0f, 1.0f);
			float flg = basisu::clamp(iz10 * (float)uq00_g + iz11 * q10_g, 0.0f, 1.0f);

			float fhb = basisu::clamp(iz00 * (float)uq00_b + iz01 * q10_b, 0.0f, 1.0f);
			float flb = basisu::clamp(iz10 * (float)uq00_b + iz11 * q10_b, 0.0f, 1.0f);

			lr = to_7(flr); lg = to_7(flg); lb = to_7(flb);
			hr = to_7(fhr); hg = to_7(fhg); hb = to_7(fhb);

			return true;
		}

		void encode_bc7_mode_5_block(void* pDst_block, color32* pPixels, bool hq_mode)
		{
			assert(g_mode5_rgba_midpoints[1]);

			int total_r = 0, total_g = 0, total_b = 0;

			int min_r = 255, min_g = 255, min_b = 255;
			int max_r = 0, max_g = 0, max_b = 0;

			for (uint32_t i = 0; i < 16; i++)
			{
				int r = pPixels[i].r, g = pPixels[i].g, b = pPixels[i].b;

				total_r += r; total_g += g; total_b += b;

				min_r = basisu::minimum(min_r, r); min_g = basisu::minimum(min_g, g); min_b = basisu::minimum(min_b, b);
				max_r = basisu::maximum(max_r, r); max_g = basisu::maximum(max_g, g); max_b = basisu::maximum(max_b, b);
			}

			if ((min_r == max_r) && (min_g == max_g) && (min_b == max_b))
			{
				const int lr = g_bc7_m5_equals_1[min_r].m_lo, lg = g_bc7_m5_equals_1[min_g].m_lo, lb = g_bc7_m5_equals_1[min_b].m_lo;
				const int hr = g_bc7_m5_equals_1[min_r].m_hi, hg = g_bc7_m5_equals_1[min_g].m_hi, hb = g_bc7_m5_equals_1[min_b].m_hi;
				uint8_t solid_weights[16];
				memset(solid_weights, 1, 16);
				pack_bc7_mode5_rgb_block((bc7_mode_5*)pDst_block, lr, lg, lb, hr, hg, hb, solid_weights);
				return;
			}

			int mean_r = (total_r + 8) >> 4, mean_g = (total_g + 8) >> 4, mean_b = (total_b + 8) >> 4;

			// covar rows are:
			// 0, 1, 2
			// 1, 3, 4
			// 2, 4, 5
			int icov[6] = { 0, 0, 0, 0, 0, 0 };

			for (uint32_t i = 0; i < 16; i++)
			{
				int r = (int)pPixels[i].r - mean_r;
				int g = (int)pPixels[i].g - mean_g;
				int b = (int)pPixels[i].b - mean_b;
				icov[0] += r * r; icov[1] += r * g; icov[2] += r * b;
				icov[3] += g * g; icov[4] += g * b;
				icov[5] += b * b;
			}

			int block_max_var = basisu::maximum(icov[0], icov[3], icov[5]); // not divided by 16, i.e. scaled by 16
			
			// TODO: Tune this
			const int32_t SIMPLE_BLOCK_THRESH = 10 * 16;
						
			if ((!hq_mode) && (block_max_var < SIMPLE_BLOCK_THRESH))
			{
				const int L = 16, H = 239;

				int lr = to_7(lerp_8bit(min_r, max_r, L));
				int lg = to_7(lerp_8bit(min_g, max_g, L));
				int lb = to_7(lerp_8bit(min_b, max_b, L));

				int hr = to_7(lerp_8bit(min_r, max_r, H));
				int hg = to_7(lerp_8bit(min_g, max_g, H));
				int hb = to_7(lerp_8bit(min_b, max_b, H));

				uint8_t cur_weights[16];
				eval_weights(pPixels, cur_weights, lr, lg, lb, hr, hg, hb);

				pack_bc7_mode5_rgb_block((bc7_mode_5*)pDst_block, lr, lg, lb, hr, hg, hb, cur_weights);
				return;
			}

			float cov[6];
			for (uint32_t i = 0; i < 6; i++)
				cov[i] = (float)icov[i];

			const float sc = 1.0f / (float)block_max_var;
			const float wx = sc * cov[0], wy = sc * cov[3], wz = sc * cov[5];

			const float alt_xr = cov[0] * wx + cov[1] * wy + cov[2] * wz;
			const float alt_xg = cov[1] * wx + cov[3] * wy + cov[4] * wz;
			const float alt_xb = cov[2] * wx + cov[4] * wy + cov[5] * wz;

			int saxis_r = 306, saxis_g = 601, saxis_b = 117;

			float k = basisu::maximum(fabsf(alt_xr), fabsf(alt_xg), fabsf(alt_xb));
			if (fabs(k) >= basisu::SMALL_FLOAT_VAL)
			{
				float m = 2048.0f / k;
				saxis_r = (int)(alt_xr * m);
				saxis_g = (int)(alt_xg * m);
				saxis_b = (int)(alt_xb * m);
			}
						
			saxis_r = (int)((uint32_t)saxis_r << 4U);
			saxis_g = (int)((uint32_t)saxis_g << 4U);
			saxis_b = (int)((uint32_t)saxis_b << 4U);

			int low_dot = INT_MAX, high_dot = INT_MIN;

			for (uint32_t i = 0; i < 16; i += 4)
			{
				int dot0 = ((pPixels[i].r * saxis_r + pPixels[i].g * saxis_g + pPixels[i].b * saxis_b) & ~0xF) + i;
				int dot1 = ((pPixels[i + 1].r * saxis_r + pPixels[i + 1].g * saxis_g + pPixels[i + 1].b * saxis_b) & ~0xF) + i + 1;
				int dot2 = ((pPixels[i + 2].r * saxis_r + pPixels[i + 2].g * saxis_g + pPixels[i + 2].b * saxis_b) & ~0xF) + i + 2;
				int dot3 = ((pPixels[i + 3].r * saxis_r + pPixels[i + 3].g * saxis_g + pPixels[i + 3].b * saxis_b) & ~0xF) + i + 3;

				int min_d01 = basisu::minimum(dot0, dot1);
				int max_d01 = basisu::maximum(dot0, dot1);

				int min_d23 = basisu::minimum(dot2, dot3);
				int max_d23 = basisu::maximum(dot2, dot3);

				int min_d = basisu::minimum(min_d01, min_d23);
				int max_d = basisu::maximum(max_d01, max_d23);

				low_dot = basisu::minimum(low_dot, min_d);
				high_dot = basisu::maximum(high_dot, max_d);
			}
			int low_c = low_dot & 15;
			int high_c = high_dot & 15;

			int lr = to_7(pPixels[low_c].r), lg = to_7(pPixels[low_c].g), lb = to_7(pPixels[low_c].b);
			int hr = to_7(pPixels[high_c].r), hg = to_7(pPixels[high_c].g), hb = to_7(pPixels[high_c].b);

			uint8_t cur_weights[16];
			eval_weights(pPixels, cur_weights, lr, lg, lb, hr, hg, hb);

			if (compute_least_squares_endpoints4_rgb(
				pPixels, cur_weights,
				lr, lg, lb, hr, hg, hb,
				total_r, total_g, total_b))
			{
				eval_weights(pPixels, cur_weights, lr, lg, lb, hr, hg, hb);
			}

#if 0
			lr = 0; lg = 0; lb = 0;
			hr = 0; hg = 0; hb = 0;
#endif

			pack_bc7_mode5_rgb_block((bc7_mode_5*)pDst_block, lr, lg, lb, hr, hg, hb, cur_weights);
		}

	} // namespace bc7_mode_5_encoder

#endif // BASISD_SUPPORT_BC7_MODE5

	//------------------------------------------------------------------------------------------------

	basisu_lowlevel_etc1s_transcoder::basisu_lowlevel_etc1s_transcoder() :
		m_pGlobal_codebook(nullptr),
		m_selector_history_buf_size(0)
	{
	}

	bool basisu_lowlevel_etc1s_transcoder::decode_palettes(
		uint32_t num_endpoints, const uint8_t* pEndpoints_data, uint32_t endpoints_data_size,
		uint32_t num_selectors, const uint8_t* pSelectors_data, uint32_t selectors_data_size)
	{
		if (m_pGlobal_codebook)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: fail 11\n");
			return false;
		}
		bitwise_decoder sym_codec;

		huffman_decoding_table color5_delta_model0, color5_delta_model1, color5_delta_model2, inten_delta_model;

		if (!sym_codec.init(pEndpoints_data, endpoints_data_size))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: fail 0\n");
			return false;
		}

		if (!sym_codec.read_huffman_table(color5_delta_model0))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: fail 1\n");
			return false;
		}

		if (!sym_codec.read_huffman_table(color5_delta_model1))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: fail 1a\n");
			return false;
		}

		if (!sym_codec.read_huffman_table(color5_delta_model2))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: fail 2a\n");
			return false;
		}

		if (!sym_codec.read_huffman_table(inten_delta_model))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: fail 2b\n");
			return false;
		}

		if (!color5_delta_model0.is_valid() || !color5_delta_model1.is_valid() || !color5_delta_model2.is_valid() || !inten_delta_model.is_valid())
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: fail 2b\n");
			return false;
		}

		const bool endpoints_are_grayscale = sym_codec.get_bits(1) != 0;

		m_local_endpoints.resize(num_endpoints);

		color32 prev_color5(16, 16, 16, 0);
		uint32_t prev_inten = 0;

		for (uint32_t i = 0; i < num_endpoints; i++)
		{
			uint32_t inten_delta = sym_codec.decode_huffman(inten_delta_model);
			m_local_endpoints[i].m_inten5 = static_cast<uint8_t>((inten_delta + prev_inten) & 7);
			prev_inten = m_local_endpoints[i].m_inten5;

			for (uint32_t c = 0; c < (endpoints_are_grayscale ? 1U : 3U); c++)
			{
				int delta;
				if (prev_color5[c] <= basist::COLOR5_PAL0_PREV_HI)
					delta = sym_codec.decode_huffman(color5_delta_model0);
				else if (prev_color5[c] <= basist::COLOR5_PAL1_PREV_HI)
					delta = sym_codec.decode_huffman(color5_delta_model1);
				else
					delta = sym_codec.decode_huffman(color5_delta_model2);

				int v = (prev_color5[c] + delta) & 31;

				m_local_endpoints[i].m_color5[c] = static_cast<uint8_t>(v);

				prev_color5[c] = static_cast<uint8_t>(v);
			}

			if (endpoints_are_grayscale)
			{
				m_local_endpoints[i].m_color5[1] = m_local_endpoints[i].m_color5[0];
				m_local_endpoints[i].m_color5[2] = m_local_endpoints[i].m_color5[0];
			}
		}

		sym_codec.stop();

		m_local_selectors.resize(num_selectors);
		
		if (!sym_codec.init(pSelectors_data, selectors_data_size))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: fail 5\n");
			return false;
		}

		basist::huffman_decoding_table delta_selector_pal_model;

		const bool used_global_selector_cb = (sym_codec.get_bits(1) == 1);

		if (used_global_selector_cb)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: global selector codebooks are unsupported\n");
			return false;
		}
		else
		{
			const bool used_hybrid_selector_cb = (sym_codec.get_bits(1) == 1);

			if (used_hybrid_selector_cb)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: hybrid global selector codebooks are unsupported\n");
				return false;
			}
				
			const bool used_raw_encoding = (sym_codec.get_bits(1) == 1);

			if (used_raw_encoding)
			{
				for (uint32_t i = 0; i < num_selectors; i++)
				{
					for (uint32_t j = 0; j < 4; j++)
					{
						uint32_t cur_byte = sym_codec.get_bits(8);

						for (uint32_t k = 0; k < 4; k++)
							m_local_selectors[i].set_selector(k, j, (cur_byte >> (k * 2)) & 3);
					}

					m_local_selectors[i].init_flags();
				}
			}
			else
			{
				if (!sym_codec.read_huffman_table(delta_selector_pal_model))
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: fail 10\n");
					return false;
				}

				if ((num_selectors > 1) && (!delta_selector_pal_model.is_valid()))
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: fail 10a\n");
					return false;
				}

				uint8_t prev_bytes[4] = { 0, 0, 0, 0 };

				for (uint32_t i = 0; i < num_selectors; i++)
				{
					if (!i)
					{
						for (uint32_t j = 0; j < 4; j++)
						{
							uint32_t cur_byte = sym_codec.get_bits(8);
							prev_bytes[j] = static_cast<uint8_t>(cur_byte);

							for (uint32_t k = 0; k < 4; k++)
								m_local_selectors[i].set_selector(k, j, (cur_byte >> (k * 2)) & 3);
						}
						m_local_selectors[i].init_flags();
						continue;
					}

					for (uint32_t j = 0; j < 4; j++)
					{
						int delta_byte = sym_codec.decode_huffman(delta_selector_pal_model);

						uint32_t cur_byte = delta_byte ^ prev_bytes[j];
						prev_bytes[j] = static_cast<uint8_t>(cur_byte);

						for (uint32_t k = 0; k < 4; k++)
							m_local_selectors[i].set_selector(k, j, (cur_byte >> (k * 2)) & 3);
					}
					m_local_selectors[i].init_flags();
				}
			}
		}

		sym_codec.stop();

		return true;
	}

	bool basisu_lowlevel_etc1s_transcoder::decode_tables(const uint8_t* pTable_data, uint32_t table_data_size)
	{
		basist::bitwise_decoder sym_codec;
		if (!sym_codec.init(pTable_data, table_data_size))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_tables: fail 0\n");
			return false;
		}

		if (!sym_codec.read_huffman_table(m_endpoint_pred_model))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_tables: fail 1\n");
			return false;
		}

		if (m_endpoint_pred_model.get_code_sizes().size() == 0)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_tables: fail 1a\n");
			return false;
		}

		if (!sym_codec.read_huffman_table(m_delta_endpoint_model))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_tables: fail 2\n");
			return false;
		}

		if (m_delta_endpoint_model.get_code_sizes().size() == 0)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_tables: fail 2a\n");
			return false;
		}

		if (!sym_codec.read_huffman_table(m_selector_model))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_tables: fail 3\n");
			return false;
		}

		if (m_selector_model.get_code_sizes().size() == 0)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_tables: fail 3a\n");
			return false;
		}

		if (!sym_codec.read_huffman_table(m_selector_history_buf_rle_model))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_tables: fail 4\n");
			return false;
		}

		if (m_selector_history_buf_rle_model.get_code_sizes().size() == 0)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_tables: fail 4a\n");
			return false;
		}

		m_selector_history_buf_size = sym_codec.get_bits(13);
		// Check for bogus values.
		if (!m_selector_history_buf_size)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_tables: fail 5\n");
			return false;
		}

		sym_codec.stop();

		return true;
	}

	bool basisu_lowlevel_etc1s_transcoder::transcode_slice(void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y, const uint8_t* pImage_data, uint32_t image_data_size, block_format fmt,
		uint32_t output_block_or_pixel_stride_in_bytes, bool bc1_allow_threecolor_blocks, const bool is_video, const bool is_alpha_slice, const uint32_t level_index, const uint32_t orig_width, const uint32_t orig_height, uint32_t output_row_pitch_in_blocks_or_pixels,
		basisu_transcoder_state* pState, bool transcode_alpha, void *pAlpha_blocks, uint32_t output_rows_in_pixels, uint32_t decode_flags)
	{
		// 'pDst_blocks' unused when disabling *all* hardware transcode options
		// (and 'bc1_allow_threecolor_blocks' when disabling DXT)
		BASISU_NOTE_UNUSED(pDst_blocks);
		BASISU_NOTE_UNUSED(bc1_allow_threecolor_blocks);
		BASISU_NOTE_UNUSED(transcode_alpha);
		BASISU_NOTE_UNUSED(pAlpha_blocks);

		assert(g_transcoder_initialized);
		if (!g_transcoder_initialized)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: Transcoder not globally initialized.\n");
			return false;
		}

		if (!pState)
			pState = &m_def_state;

		const uint32_t total_blocks = num_blocks_x * num_blocks_y;

		if (!output_row_pitch_in_blocks_or_pixels)
		{
			if (basis_block_format_is_uncompressed(fmt))
				output_row_pitch_in_blocks_or_pixels = orig_width;
			else
			{
				if (fmt == block_format::cFXT1_RGB)
					output_row_pitch_in_blocks_or_pixels = (orig_width + 7) / 8;
				else
					output_row_pitch_in_blocks_or_pixels = num_blocks_x;
			}
		}

		if (basis_block_format_is_uncompressed(fmt))
		{
			if (!output_rows_in_pixels)
				output_rows_in_pixels = orig_height;
		}
		
		basisu::vector<uint32_t>* pPrev_frame_indices = nullptr;
		if (is_video)
		{
			// TODO: Add check to make sure the caller hasn't tried skipping past p-frames
			//const bool alpha_flag = (slice_desc.m_flags & cSliceDescFlagsHasAlpha) != 0;
			//const uint32_t level_index = slice_desc.m_level_index;

			if (level_index >= basisu_transcoder_state::cMaxPrevFrameLevels)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: unsupported level_index\n");
				return false;
			}

			pPrev_frame_indices = &pState->m_prev_frame_indices[is_alpha_slice][level_index];
			if (pPrev_frame_indices->size() < total_blocks)
				pPrev_frame_indices->resize(total_blocks);
		}

		basist::bitwise_decoder sym_codec;

		if (!sym_codec.init(pImage_data, image_data_size))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: sym_codec.init failed\n");
			return false;
		}

		approx_move_to_front selector_history_buf(m_selector_history_buf_size);
				
		uint32_t cur_selector_rle_count = 0;

		decoder_etc_block block;
		memset(&block, 0, sizeof(block));
				
		//block.set_flip_bit(true);
		// Setting the flip bit to false to be compatible with the Khronos KDFS.
		block.set_flip_bit(false);

		block.set_diff_bit(true);

		// Important: This MUST be freed before this function returns.
		void* pPVRTC_work_mem = nullptr;
		uint32_t* pPVRTC_endpoints = nullptr;
		if ((fmt == block_format::cPVRTC1_4_RGB) || (fmt == block_format::cPVRTC1_4_RGBA))
		{
			pPVRTC_work_mem = malloc(num_blocks_x * num_blocks_y * (sizeof(decoder_etc_block) + sizeof(uint32_t)));
			if (!pPVRTC_work_mem)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: malloc failed\n");
				return false;
			}
			pPVRTC_endpoints = (uint32_t*)&((decoder_etc_block*)pPVRTC_work_mem)[num_blocks_x * num_blocks_y];
		}

		if (pState->m_block_endpoint_preds[0].size() < num_blocks_x)
		{
			pState->m_block_endpoint_preds[0].resize(num_blocks_x);
			pState->m_block_endpoint_preds[1].resize(num_blocks_x);
		}

		uint32_t cur_pred_bits = 0;
		int prev_endpoint_pred_sym = 0;
		int endpoint_pred_repeat_count = 0;
		uint32_t prev_endpoint_index = 0;
		const endpoint_vec& endpoints = m_pGlobal_codebook ? m_pGlobal_codebook->m_local_endpoints : m_local_endpoints;
		const selector_vec& selectors = m_pGlobal_codebook ? m_pGlobal_codebook->m_local_selectors : m_local_selectors;
		if (!endpoints.size() || !selectors.size())
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: global codebooks must be unpacked first\n");
			
			if (pPVRTC_work_mem)
				free(pPVRTC_work_mem);

			return false;
		}

		const uint32_t SELECTOR_HISTORY_BUF_FIRST_SYMBOL_INDEX = (uint32_t)selectors.size();
		const uint32_t SELECTOR_HISTORY_BUF_RLE_SYMBOL_INDEX = m_selector_history_buf_size + SELECTOR_HISTORY_BUF_FIRST_SYMBOL_INDEX;

#if BASISD_SUPPORT_BC7_MODE5
		const bool bc7_chroma_filtering = ((decode_flags & cDecodeFlagsNoETC1SChromaFiltering) == 0) && 
			((fmt == block_format::cBC7_M5_COLOR) || (fmt == block_format::cBC7));

		basisu::vector2D<uint16_t> decoded_endpoints;
		if (bc7_chroma_filtering)
		{
			if (!decoded_endpoints.try_resize(num_blocks_x, num_blocks_y))
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: allocation failed\n");

				if (pPVRTC_work_mem)
					free(pPVRTC_work_mem);

				return false;
			}
		}
#endif

		for (uint32_t block_y = 0; block_y < num_blocks_y; block_y++)
		{
			const uint32_t cur_block_endpoint_pred_array = block_y & 1;

			for (uint32_t block_x = 0; block_x < num_blocks_x; block_x++)
			{
				// Decode endpoint index predictor symbols
				if ((block_x & 1) == 0)
				{
					if ((block_y & 1) == 0)
					{
						if (endpoint_pred_repeat_count)
						{
							endpoint_pred_repeat_count--;
							cur_pred_bits = prev_endpoint_pred_sym;
						}
						else
						{
							cur_pred_bits = sym_codec.decode_huffman(m_endpoint_pred_model);
							if (cur_pred_bits == ENDPOINT_PRED_REPEAT_LAST_SYMBOL)
							{
								endpoint_pred_repeat_count = sym_codec.decode_vlc(ENDPOINT_PRED_COUNT_VLC_BITS) + ENDPOINT_PRED_MIN_REPEAT_COUNT - 1;

								cur_pred_bits = prev_endpoint_pred_sym;
							}
							else
							{
								prev_endpoint_pred_sym = cur_pred_bits;
							}
						}

						pState->m_block_endpoint_preds[cur_block_endpoint_pred_array ^ 1][block_x].m_pred_bits = (uint8_t)(cur_pred_bits >> 4);
					}
					else
					{
						cur_pred_bits = pState->m_block_endpoint_preds[cur_block_endpoint_pred_array][block_x].m_pred_bits;
					}
				}

				// Decode endpoint index
				uint32_t endpoint_index, selector_index = 0;

				const uint32_t pred = cur_pred_bits & 3;
				cur_pred_bits >>= 2;

				if (pred == 0)
				{
					// Left
					if (!block_x)
					{
						BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: invalid datastream (0)\n");
						if (pPVRTC_work_mem)
							free(pPVRTC_work_mem);
						return false;
					}

					endpoint_index = prev_endpoint_index;
				}
				else if (pred == 1)
				{
					// Upper
					if (!block_y)
					{
						BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: invalid datastream (1)\n");
						if (pPVRTC_work_mem)
							free(pPVRTC_work_mem);
						return false;
					}

					endpoint_index = pState->m_block_endpoint_preds[cur_block_endpoint_pred_array ^ 1][block_x].m_endpoint_index;
				}
				else if (pred == 2)
				{
					if (is_video)
					{
						assert(pred == CR_ENDPOINT_PRED_INDEX);
						endpoint_index = (*pPrev_frame_indices)[block_x + block_y * num_blocks_x];
						selector_index = endpoint_index >> 16;
						endpoint_index &= 0xFFFFU;
					}
					else
					{
						// Upper left
						if ((!block_x) || (!block_y))
						{
							BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: invalid datastream (2)\n");
							if (pPVRTC_work_mem)
								free(pPVRTC_work_mem);
							return false;
						}

						endpoint_index = pState->m_block_endpoint_preds[cur_block_endpoint_pred_array ^ 1][block_x - 1].m_endpoint_index;
					}
				}
				else
				{
					// Decode and apply delta
					const uint32_t delta_sym = sym_codec.decode_huffman(m_delta_endpoint_model);

					endpoint_index = delta_sym + prev_endpoint_index;
					if (endpoint_index >= endpoints.size())
						endpoint_index -= (int)endpoints.size();
				}

				pState->m_block_endpoint_preds[cur_block_endpoint_pred_array][block_x].m_endpoint_index = (uint16_t)endpoint_index;

				prev_endpoint_index = endpoint_index;

				// Decode selector index
				if ((!is_video) || (pred != CR_ENDPOINT_PRED_INDEX))
				{
					int selector_sym;
					if (cur_selector_rle_count > 0)
					{
						cur_selector_rle_count--;

						selector_sym = (int)selectors.size();
					}
					else
					{
						selector_sym = sym_codec.decode_huffman(m_selector_model);

						if (selector_sym == static_cast<int>(SELECTOR_HISTORY_BUF_RLE_SYMBOL_INDEX))
						{
							int run_sym = sym_codec.decode_huffman(m_selector_history_buf_rle_model);

							if (run_sym == (SELECTOR_HISTORY_BUF_RLE_COUNT_TOTAL - 1))
								cur_selector_rle_count = sym_codec.decode_vlc(7) + SELECTOR_HISTORY_BUF_RLE_COUNT_THRESH;
							else
								cur_selector_rle_count = run_sym + SELECTOR_HISTORY_BUF_RLE_COUNT_THRESH;

							if (cur_selector_rle_count > total_blocks)
							{
								// The file is corrupted or we've got a bug.
								BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: invalid datastream (3)\n");
								if (pPVRTC_work_mem)
									free(pPVRTC_work_mem);
								return false;
							}

							selector_sym = (int)selectors.size();

							cur_selector_rle_count--;
						}
					}

					if (selector_sym >= (int)selectors.size())
					{
						assert(m_selector_history_buf_size > 0);

						int history_buf_index = selector_sym - (int)selectors.size();

						if (history_buf_index >= (int)selector_history_buf.size())
						{
							// The file is corrupted or we've got a bug.
							BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: invalid datastream (4)\n");
							if (pPVRTC_work_mem)
								free(pPVRTC_work_mem);
							return false;
						}

						selector_index = selector_history_buf[history_buf_index];

						if (history_buf_index != 0)
							selector_history_buf.use(history_buf_index);
					}
					else
					{
						selector_index = selector_sym;

						if (m_selector_history_buf_size)
							selector_history_buf.add(selector_index);
					}
				}

				if ((endpoint_index >= endpoints.size()) || (selector_index >= selectors.size()))
				{
					// The file is corrupted or we've got a bug.
					BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: invalid datastream (5)\n");
					if (pPVRTC_work_mem)
						free(pPVRTC_work_mem);
					return false;
				}

				if (is_video)
					(*pPrev_frame_indices)[block_x + block_y * num_blocks_x] = endpoint_index | (selector_index << 16);

#if BASISD_ENABLE_DEBUG_FLAGS
				if ((g_debug_flags & cDebugFlagVisCRs) && ((fmt == block_format::cETC1) || (fmt == block_format::cBC1)))
				{
					if ((is_video) && (pred == 2))
					{
						decoder_etc_block* pDst_block = reinterpret_cast<decoder_etc_block*>(static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes);
						memset(pDst_block, 0xFF, 8);
						continue;
					}
				}
#endif

				const endpoint* pEndpoints = &endpoints[endpoint_index];
				const selector* pSelector = &selectors[selector_index];

				switch (fmt)
				{
				case block_format::cETC1:
				{
					decoder_etc_block* pDst_block = reinterpret_cast<decoder_etc_block*>(static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes);
					
					block.set_base5_color(decoder_etc_block::pack_color5(pEndpoints->m_color5, false));
					block.set_inten_table(0, pEndpoints->m_inten5);
					block.set_inten_table(1, pEndpoints->m_inten5);

					pDst_block->m_uint32[0] = block.m_uint32[0];
					pDst_block->set_raw_selector_bits(pSelector->m_bytes[0], pSelector->m_bytes[1], pSelector->m_bytes[2], pSelector->m_bytes[3]);

					break;
				}
				case block_format::cBC1:
				{
#if BASISD_SUPPORT_DXT1
					void* pDst_block = static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes;
#if BASISD_ENABLE_DEBUG_FLAGS
					if (g_debug_flags & (cDebugFlagVisBC1Sels | cDebugFlagVisBC1Endpoints))
						convert_etc1s_to_dxt1_vis(static_cast<dxt1_block*>(pDst_block), pEndpoints, pSelector, bc1_allow_threecolor_blocks);
					else
#endif
						convert_etc1s_to_dxt1(static_cast<dxt1_block*>(pDst_block), pEndpoints, pSelector, bc1_allow_threecolor_blocks);
#else
					assert(0);
#endif
					break;
				}
				case block_format::cBC4:
				{
#if BASISD_SUPPORT_DXT5A
					void* pDst_block = static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes;
					convert_etc1s_to_dxt5a(static_cast<dxt5a_block*>(pDst_block), pEndpoints, pSelector);
#else
					assert(0);
#endif
					break;
				}
				case block_format::cPVRTC1_4_RGB:
				{
#if BASISD_SUPPORT_PVRTC1
					block.set_base5_color(decoder_etc_block::pack_color5(pEndpoints->m_color5, false));
					block.set_inten_table(0, pEndpoints->m_inten5);
					block.set_inten_table(1, pEndpoints->m_inten5);
					block.set_raw_selector_bits(pSelector->m_bytes[0], pSelector->m_bytes[1], pSelector->m_bytes[2], pSelector->m_bytes[3]);

					((decoder_etc_block*)pPVRTC_work_mem)[block_x + block_y * num_blocks_x] = block;

					const color32& base_color = pEndpoints->m_color5;
					const uint32_t inten_table = pEndpoints->m_inten5;

					const uint32_t low_selector = pSelector->m_lo_selector;
					const uint32_t high_selector = pSelector->m_hi_selector;

					// Get block's RGB bounding box 
					color32 block_colors[2];
					decoder_etc_block::get_block_colors5_bounds(block_colors, base_color, inten_table, low_selector, high_selector);

					assert(block_colors[0][0] <= block_colors[1][0]);
					assert(block_colors[0][1] <= block_colors[1][1]);
					assert(block_colors[0][2] <= block_colors[1][2]);

					// Set PVRTC1 endpoints to floor/ceil of bounding box's coordinates.
					pvrtc4_block temp;
					temp.set_opaque_endpoint_floor(0, block_colors[0]);
					temp.set_opaque_endpoint_ceil(1, block_colors[1]);

					pPVRTC_endpoints[block_x + block_y * num_blocks_x] = temp.m_endpoints;
#else
					assert(0);
#endif	

					break;
				}
				case block_format::cPVRTC1_4_RGBA:
				{
#if BASISD_SUPPORT_PVRTC1
					assert(pAlpha_blocks);
					
					block.set_base5_color(decoder_etc_block::pack_color5(pEndpoints->m_color5, false));
					block.set_inten_table(0, pEndpoints->m_inten5);
					block.set_inten_table(1, pEndpoints->m_inten5);
					block.set_raw_selector_bits(pSelector->m_selectors[0], pSelector->m_selectors[1], pSelector->m_selectors[2], pSelector->m_selectors[3]);

					((decoder_etc_block*)pPVRTC_work_mem)[block_x + block_y * num_blocks_x] = block;

					// Get block's RGBA bounding box 
					const color32& base_color = pEndpoints->m_color5;
					const uint32_t inten_table = pEndpoints->m_inten5;
					const uint32_t low_selector = pSelector->m_lo_selector;
					const uint32_t high_selector = pSelector->m_hi_selector;
					color32 block_colors[2];
					decoder_etc_block::get_block_colors5_bounds(block_colors, base_color, inten_table, low_selector, high_selector);

					assert(block_colors[0][0] <= block_colors[1][0]);
					assert(block_colors[0][1] <= block_colors[1][1]);
					assert(block_colors[0][2] <= block_colors[1][2]);

					const uint16_t* pAlpha_block = reinterpret_cast<uint16_t*>(static_cast<uint8_t*>(pAlpha_blocks) + (block_x + block_y * num_blocks_x) * sizeof(uint32_t));

					const endpoint* pAlpha_endpoints = &endpoints[pAlpha_block[0]];
					const selector* pAlpha_selector = &selectors[pAlpha_block[1]];

					const color32& alpha_base_color = pAlpha_endpoints->m_color5;
					const uint32_t alpha_inten_table = pAlpha_endpoints->m_inten5;
					const uint32_t alpha_low_selector = pAlpha_selector->m_lo_selector;
					const uint32_t alpha_high_selector = pAlpha_selector->m_hi_selector;
					uint32_t alpha_block_colors[2];
					decoder_etc_block::get_block_colors5_bounds_g(alpha_block_colors, alpha_base_color, alpha_inten_table, alpha_low_selector, alpha_high_selector);
					assert(alpha_block_colors[0] <= alpha_block_colors[1]);
					block_colors[0].a = (uint8_t)alpha_block_colors[0];
					block_colors[1].a = (uint8_t)alpha_block_colors[1];

					// Set PVRTC1 endpoints to floor/ceil of bounding box's coordinates.
					pvrtc4_block temp;
					temp.set_endpoint_floor(0, block_colors[0]);
					temp.set_endpoint_ceil(1, block_colors[1]);

					pPVRTC_endpoints[block_x + block_y * num_blocks_x] = temp.m_endpoints;
#else
					assert(0);
#endif	

					break;
				}
				case block_format::cBC7:				// for more consistency with UASTC
				case block_format::cBC7_M5_COLOR:
				{
#if BASISD_SUPPORT_BC7_MODE5
					if (bc7_chroma_filtering)
					{
						assert(endpoint_index <= UINT16_MAX);
						decoded_endpoints(block_x, block_y) = (uint16_t)endpoint_index;
					}

					void* pDst_block = static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes;
					convert_etc1s_to_bc7_m5_color(pDst_block, pEndpoints, pSelector);
#else
					assert(0);
#endif
					break;
				}
				case block_format::cBC7_M5_ALPHA:
				{
#if BASISD_SUPPORT_BC7_MODE5
					void* pDst_block = static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes;
					convert_etc1s_to_bc7_m5_alpha(pDst_block, pEndpoints, pSelector);
#else
					assert(0);
#endif
					break;
				}
				case block_format::cETC2_EAC_A8:
				{
#if BASISD_SUPPORT_ETC2_EAC_A8
					void* pDst_block = static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes;
					convert_etc1s_to_etc2_eac_a8(static_cast<eac_block*>(pDst_block), pEndpoints, pSelector);
#else
					assert(0);
#endif
					break;
				}
				case block_format::cASTC_4x4:
				{
#if BASISD_SUPPORT_ASTC
					void* pDst_block = static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes;
					convert_etc1s_to_astc_4x4(pDst_block, pEndpoints, pSelector, transcode_alpha, &endpoints[0], &selectors[0]);
#else
					assert(0);
#endif
					break;
				}
				case block_format::cATC_RGB:
				{
#if BASISD_SUPPORT_ATC
					void* pDst_block = static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes;
					convert_etc1s_to_atc(pDst_block, pEndpoints, pSelector);
#else
					assert(0);
#endif
					break;
				}
				case block_format::cFXT1_RGB:
				{
#if BASISD_SUPPORT_FXT1
					const uint32_t fxt1_block_x = block_x >> 1;
					const uint32_t fxt1_block_y = block_y;
					const uint32_t fxt1_subblock = block_x & 1;

					void* pDst_block = static_cast<uint8_t*>(pDst_blocks) + (fxt1_block_x + fxt1_block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes;

					convert_etc1s_to_fxt1(pDst_block, pEndpoints, pSelector, fxt1_subblock);
#else
					assert(0);
#endif
					break;
				}
				case block_format::cPVRTC2_4_RGB:
				{
#if BASISD_SUPPORT_PVRTC2
					void* pDst_block = static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes;
					convert_etc1s_to_pvrtc2_rgb(pDst_block, pEndpoints, pSelector);
#endif
					break;
				}
				case block_format::cPVRTC2_4_RGBA:
				{
#if BASISD_SUPPORT_PVRTC2
					assert(transcode_alpha);

					void* pDst_block = static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes;
										
					convert_etc1s_to_pvrtc2_rgba(pDst_block, pEndpoints, pSelector, &endpoints[0], &selectors[0]);
#endif
					break;
				}
				case block_format::cIndices:
				{
					uint16_t* pDst_block = reinterpret_cast<uint16_t *>(static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes);
					pDst_block[0] = static_cast<uint16_t>(endpoint_index);
					pDst_block[1] = static_cast<uint16_t>(selector_index);
					break;
				}
				case block_format::cA32:
				{
					assert(sizeof(uint32_t) == output_block_or_pixel_stride_in_bytes);
					uint8_t* pDst_pixels = static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint32_t);
										
					const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
					const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);
					
					int colors[4];
					decoder_etc_block::get_block_colors5_g(colors, pEndpoints->m_color5, pEndpoints->m_inten5);

					if (max_x == 4)
					{
						for (uint32_t y = 0; y < max_y; y++)
						{
							const uint32_t s = pSelector->m_selectors[y];

							pDst_pixels[3] = static_cast<uint8_t>(colors[s & 3]);
							pDst_pixels[3+4] = static_cast<uint8_t>(colors[(s >> 2) & 3]);
							pDst_pixels[3+8] = static_cast<uint8_t>(colors[(s >> 4) & 3]);
							pDst_pixels[3+12] = static_cast<uint8_t>(colors[(s >> 6) & 3]);
							
							pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint32_t);
						}
					}
					else
					{
						for (uint32_t y = 0; y < max_y; y++)
						{
							const uint32_t s = pSelector->m_selectors[y];

							for (uint32_t x = 0; x < max_x; x++)
								pDst_pixels[3 + 4 * x] = static_cast<uint8_t>(colors[(s >> (x * 2)) & 3]);

							pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint32_t);
						}
					}

					break;
				}
				case block_format::cRGB32:
				{
					assert(sizeof(uint32_t) == output_block_or_pixel_stride_in_bytes);
					uint8_t* pDst_pixels = static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint32_t);

					const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
					const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

					color32 colors[4];
					decoder_etc_block::get_block_colors5(colors, pEndpoints->m_color5, pEndpoints->m_inten5);
					
					for (uint32_t y = 0; y < max_y; y++)
					{
						const uint32_t s = pSelector->m_selectors[y];

						for (uint32_t x = 0; x < max_x; x++)
						{
							const color32& c = colors[(s >> (x * 2)) & 3];

							pDst_pixels[0 + 4 * x] = c.r;
							pDst_pixels[1 + 4 * x] = c.g;
							pDst_pixels[2 + 4 * x] = c.b;
						}

						pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint32_t);
					}

					break;
				}
				case block_format::cRGBA32:
				{
					assert(sizeof(uint32_t) == output_block_or_pixel_stride_in_bytes);
					uint8_t* pDst_pixels = static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint32_t);

					const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
					const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

					color32 colors[4];
					decoder_etc_block::get_block_colors5(colors, pEndpoints->m_color5, pEndpoints->m_inten5);

					for (uint32_t y = 0; y < max_y; y++)
					{
						const uint32_t s = pSelector->m_selectors[y];

						for (uint32_t x = 0; x < max_x; x++)
						{
							const color32& c = colors[(s >> (x * 2)) & 3];

							pDst_pixels[0 + 4 * x] = c.r;
							pDst_pixels[1 + 4 * x] = c.g;
							pDst_pixels[2 + 4 * x] = c.b;
							pDst_pixels[3 + 4 * x] = 255;
						}

						pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint32_t);
					}

					break;
				}
				case block_format::cRGB565:
				case block_format::cBGR565:
				{
					assert(sizeof(uint16_t) == output_block_or_pixel_stride_in_bytes);
					uint8_t* pDst_pixels = static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint16_t);

					const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
					const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

					color32 colors[4];
					decoder_etc_block::get_block_colors5(colors, pEndpoints->m_color5, pEndpoints->m_inten5);

					uint16_t packed_colors[4];
					if (fmt == block_format::cRGB565)
					{
						for (uint32_t i = 0; i < 4; i++)
						{
							packed_colors[i] = static_cast<uint16_t>((mul_8(colors[i].r, 31) << 11) | (mul_8(colors[i].g, 63) << 5) | mul_8(colors[i].b, 31));
							if (BASISD_IS_BIG_ENDIAN)
								packed_colors[i] = byteswap_uint16(packed_colors[i]);
						}
					}
					else
					{
						for (uint32_t i = 0; i < 4; i++)
						{
							packed_colors[i] = static_cast<uint16_t>((mul_8(colors[i].b, 31) << 11) | (mul_8(colors[i].g, 63) << 5) | mul_8(colors[i].r, 31));
							if (BASISD_IS_BIG_ENDIAN)
								packed_colors[i] = byteswap_uint16(packed_colors[i]);
						}
					}

					for (uint32_t y = 0; y < max_y; y++)
					{
						const uint32_t s = pSelector->m_selectors[y];

						for (uint32_t x = 0; x < max_x; x++)
							reinterpret_cast<uint16_t *>(pDst_pixels)[x] = packed_colors[(s >> (x * 2)) & 3];

						pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint16_t);
					}

					break;
				}
				case block_format::cRGBA4444_COLOR:
				{
					assert(sizeof(uint16_t) == output_block_or_pixel_stride_in_bytes);
					uint8_t* pDst_pixels = static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint16_t);

					const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
					const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

					color32 colors[4];
					decoder_etc_block::get_block_colors5(colors, pEndpoints->m_color5, pEndpoints->m_inten5);

					uint16_t packed_colors[4];
					for (uint32_t i = 0; i < 4; i++)
					{
						packed_colors[i] = static_cast<uint16_t>((mul_8(colors[i].r, 15) << 12) | (mul_8(colors[i].g, 15) << 8) | (mul_8(colors[i].b, 15) << 4));
					}

					for (uint32_t y = 0; y < max_y; y++)
					{
						const uint32_t s = pSelector->m_selectors[y];

						for (uint32_t x = 0; x < max_x; x++)
						{
							uint16_t cur = reinterpret_cast<uint16_t*>(pDst_pixels)[x];
							if (BASISD_IS_BIG_ENDIAN)
								cur = byteswap_uint16(cur);

							cur = (cur & 0xF) | packed_colors[(s >> (x * 2)) & 3];
							
							if (BASISD_IS_BIG_ENDIAN)
								cur = byteswap_uint16(cur);

							reinterpret_cast<uint16_t*>(pDst_pixels)[x] = cur;
						}

						pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint16_t);
					}

					break;
				}
				case block_format::cRGBA4444_COLOR_OPAQUE:
				{
					assert(sizeof(uint16_t) == output_block_or_pixel_stride_in_bytes);
					uint8_t* pDst_pixels = static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint16_t);

					const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
					const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

					color32 colors[4];
					decoder_etc_block::get_block_colors5(colors, pEndpoints->m_color5, pEndpoints->m_inten5);

					uint16_t packed_colors[4];
					for (uint32_t i = 0; i < 4; i++)
					{
						packed_colors[i] = static_cast<uint16_t>((mul_8(colors[i].r, 15) << 12) | (mul_8(colors[i].g, 15) << 8) | (mul_8(colors[i].b, 15) << 4) | 0xF);
						if (BASISD_IS_BIG_ENDIAN)
							packed_colors[i] = byteswap_uint16(packed_colors[i]);
					}

					for (uint32_t y = 0; y < max_y; y++)
					{
						const uint32_t s = pSelector->m_selectors[y];

						for (uint32_t x = 0; x < max_x; x++)
							reinterpret_cast<uint16_t*>(pDst_pixels)[x] = packed_colors[(s >> (x * 2)) & 3];

						pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint16_t);
					}

					break;
				}
				case block_format::cRGBA4444_ALPHA:
				{
					assert(sizeof(uint16_t) == output_block_or_pixel_stride_in_bytes);
					uint8_t* pDst_pixels = static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint16_t);

					const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
					const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

					color32 colors[4];
					decoder_etc_block::get_block_colors5(colors, pEndpoints->m_color5, pEndpoints->m_inten5);

					uint16_t packed_colors[4];
					for (uint32_t i = 0; i < 4; i++)
					{
						packed_colors[i] = mul_8(colors[i].g, 15);
						if (BASISD_IS_BIG_ENDIAN)
							packed_colors[i] = byteswap_uint16(packed_colors[i]);
					}

					for (uint32_t y = 0; y < max_y; y++)
					{
						const uint32_t s = pSelector->m_selectors[y];

						for (uint32_t x = 0; x < max_x; x++)
						{
							reinterpret_cast<uint16_t*>(pDst_pixels)[x] = packed_colors[(s >> (x * 2)) & 3];
						}

						pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint16_t);
					}

					break;
				}
				case block_format::cETC2_EAC_R11:
				{
#if BASISD_SUPPORT_ETC2_EAC_RG11
					void* pDst_block = static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes;
					convert_etc1s_to_etc2_eac_r11(static_cast<eac_block*>(pDst_block), pEndpoints, pSelector);
#else
					assert(0);
#endif
					break;
				}
				default:
				{
					assert(0);
					break;
				}
				}

			} // block_x

		} // block_y

		if (endpoint_pred_repeat_count != 0)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: endpoint_pred_repeat_count != 0. The file is corrupted or this is a bug\n");
			
			if (pPVRTC_work_mem)
				free(pPVRTC_work_mem);

			return false;
		}

		//assert(endpoint_pred_repeat_count == 0);

#if BASISD_SUPPORT_PVRTC1
		// PVRTC post process - create per-pixel modulation values.
		if (fmt == block_format::cPVRTC1_4_RGB)
			fixup_pvrtc1_4_modulation_rgb((decoder_etc_block*)pPVRTC_work_mem, pPVRTC_endpoints, pDst_blocks, num_blocks_x, num_blocks_y);
		else if (fmt == block_format::cPVRTC1_4_RGBA)
			fixup_pvrtc1_4_modulation_rgba((decoder_etc_block*)pPVRTC_work_mem, pPVRTC_endpoints, pDst_blocks, num_blocks_x, num_blocks_y, pAlpha_blocks, &endpoints[0], &selectors[0]);
#endif // BASISD_SUPPORT_PVRTC1

#if BASISD_SUPPORT_BC7_MODE5
		if (bc7_chroma_filtering)
		{
			chroma_filter_bc7_mode5(decoded_endpoints, pDst_blocks, num_blocks_x, num_blocks_y, output_row_pitch_in_blocks_or_pixels, &endpoints[0]);
		}
#endif

		if (pPVRTC_work_mem)
			free(pPVRTC_work_mem);

		return true;
	}

	bool basis_validate_output_buffer_size(
		basis_tex_format source_format,
		transcoder_texture_format target_format,
		uint32_t output_blocks_buf_size_in_blocks_or_pixels,
		uint32_t orig_width, uint32_t orig_height,
		uint32_t output_row_pitch_in_blocks_or_pixels,
		uint32_t output_rows_in_pixels)
	{
		BASISU_NOTE_UNUSED(source_format);

		if (basis_transcoder_format_is_uncompressed(target_format))
		{
			// Assume the output buffer is orig_width by orig_height
			if (!output_row_pitch_in_blocks_or_pixels)
				output_row_pitch_in_blocks_or_pixels = orig_width;

			if (!output_rows_in_pixels) 
				output_rows_in_pixels = orig_height;

			// Now make sure the output buffer is large enough, or we'll overwrite memory.
			if (output_blocks_buf_size_in_blocks_or_pixels < (output_rows_in_pixels * output_row_pitch_in_blocks_or_pixels))
			{
				BASISU_DEVEL_ERROR("basis_validate_output_buffer_size: output_blocks_buf_size_in_blocks_or_pixels < (output_rows_in_pixels * output_row_pitch_in_blocks_or_pixels)\n");
				return false;
			}
		}
		else
		{
			const uint32_t dst_block_width = basis_get_block_width(target_format);
			const uint32_t dst_block_height = basis_get_block_height(target_format);
			//const uint32_t bytes_per_block = basis_get_bytes_per_block_or_pixel(target_format);

			// Take into account the destination format's block width/height.
			const uint32_t num_dst_blocks_x = (orig_width + dst_block_width - 1) / dst_block_width;
			const uint32_t num_dst_blocks_y = (orig_height + dst_block_height - 1) / dst_block_height;
			const uint32_t total_dst_blocks = num_dst_blocks_x * num_dst_blocks_y;

			assert(total_dst_blocks);

			// Note this only computes the # of blocks we will write during transcoding, but for PVRTC1 OpenGL may require more for very small textures.
			// basis_compute_transcoded_image_size_in_bytes() may return larger buffers.
			if (output_blocks_buf_size_in_blocks_or_pixels < total_dst_blocks)
			{
				BASISU_DEVEL_ERROR("basis_validate_output_buffer_size: output_blocks_buf_size_in_blocks_or_pixels is too small\n");
				return false;
			}
		}

		return true;
	}
		
	uint32_t basis_compute_transcoded_image_size_in_bytes(transcoder_texture_format target_format, uint32_t orig_width, uint32_t orig_height)
	{
		assert(orig_width && orig_height);

		const uint32_t dst_block_width = basis_get_block_width(target_format);
		const uint32_t dst_block_height = basis_get_block_height(target_format);

		if (basis_transcoder_format_is_uncompressed(target_format))
		{
			// Uncompressed formats are just plain raster images.
			const uint32_t bytes_per_pixel = basis_get_uncompressed_bytes_per_pixel(target_format);
			const uint32_t bytes_per_line = orig_width * bytes_per_pixel;
			const uint32_t bytes_per_slice = bytes_per_line * orig_height;
			return bytes_per_slice;
		}
		
		// Compressed formats are 2D arrays of blocks.
		const uint32_t bytes_per_block = basis_get_bytes_per_block_or_pixel(target_format);

		if ((target_format == transcoder_texture_format::cTFPVRTC1_4_RGB) || (target_format == transcoder_texture_format::cTFPVRTC1_4_RGBA))
		{
			// For PVRTC1, Basis only writes (or requires) total_blocks * bytes_per_block. But GL requires extra padding for very small textures:
			// https://www.khronos.org/registry/OpenGL/extensions/IMG/IMG_texture_compression_pvrtc.txt
			const uint32_t width = (orig_width + 3) & ~3;
			const uint32_t height = (orig_height + 3) & ~3;
			const uint32_t size_in_bytes = (std::max(8U, width) * std::max(8U, height) * 4 + 7) / 8;
			return size_in_bytes;
		}

		// Take into account the destination format's block width/height.
		const uint32_t num_dst_blocks_x = (orig_width + dst_block_width - 1) / dst_block_width;
		const uint32_t num_dst_blocks_y = (orig_height + dst_block_height - 1) / dst_block_height;
		const uint32_t total_dst_blocks = num_dst_blocks_x * num_dst_blocks_y;

		assert(total_dst_blocks);

		return total_dst_blocks * bytes_per_block;
	}

	bool basisu_lowlevel_etc1s_transcoder::transcode_image(
			transcoder_texture_format target_format,
			void* pOutput_blocks, uint32_t output_blocks_buf_size_in_blocks_or_pixels,
			const uint8_t* pCompressed_data, uint32_t compressed_data_length,
			uint32_t num_blocks_x, uint32_t num_blocks_y, uint32_t orig_width, uint32_t orig_height, uint32_t level_index,
			uint64_t rgb_offset, uint32_t rgb_length, uint64_t alpha_offset, uint32_t alpha_length,
			uint32_t decode_flags,
			bool basis_file_has_alpha_slices,
			bool is_video,
			uint32_t output_row_pitch_in_blocks_or_pixels,
			basisu_transcoder_state* pState,
			uint32_t output_rows_in_pixels)
	{
		if (((uint64_t)rgb_offset + rgb_length) > (uint64_t)compressed_data_length)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: source data buffer too small (color)\n");
			return false;
		}

		if (alpha_length)
		{
			if (((uint64_t)alpha_offset + alpha_length) > (uint64_t)compressed_data_length)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: source data buffer too small (alpha)\n");
				return false;
			}
		}
		else
		{
			assert(!basis_file_has_alpha_slices);
		}

		if ((target_format == transcoder_texture_format::cTFPVRTC1_4_RGB) || (target_format == transcoder_texture_format::cTFPVRTC1_4_RGBA))
		{
			if ((!basisu::is_pow2(num_blocks_x * 4)) || (!basisu::is_pow2(num_blocks_y * 4)))
			{
				// PVRTC1 only supports power of 2 dimensions
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: PVRTC1 only supports power of 2 dimensions\n");
				return false;
			}
		}

		if ((target_format == transcoder_texture_format::cTFPVRTC1_4_RGBA) && (!basis_file_has_alpha_slices))
		{
			// Switch to PVRTC1 RGB if the input doesn't have alpha.
			target_format = transcoder_texture_format::cTFPVRTC1_4_RGB;
		}
				
		const bool transcode_alpha_data_to_opaque_formats = (decode_flags & cDecodeFlagsTranscodeAlphaDataToOpaqueFormats) != 0;
		const uint32_t bytes_per_block_or_pixel = basis_get_bytes_per_block_or_pixel(target_format);
		const uint32_t total_slice_blocks = num_blocks_x * num_blocks_y;
		
		if (!basis_validate_output_buffer_size(basis_tex_format::cETC1S, target_format, output_blocks_buf_size_in_blocks_or_pixels, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, output_rows_in_pixels))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: output buffer size too small\n");
			return false;
		}

		bool status = false;

		const uint8_t* pData = pCompressed_data + rgb_offset;
		uint32_t data_len = rgb_length;
		bool is_alpha_slice = false;

		// If the caller wants us to transcode the mip level's alpha data, then use the next slice.
		if ((basis_file_has_alpha_slices) && (transcode_alpha_data_to_opaque_formats))
		{
			pData = pCompressed_data + alpha_offset;
			data_len = alpha_length;
			is_alpha_slice = true;
		}

		switch (target_format)
		{
		case transcoder_texture_format::cTFETC1_RGB:
		{
			//status = transcode_slice(pData, data_size, slice_index_to_decode, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cETC1, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pData, data_len, block_format::cETC1, bytes_per_block_or_pixel, false, is_video, is_alpha_slice, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
							
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to ETC1 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFBC1_RGB:
		{
#if !BASISD_SUPPORT_DXT1
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: BC1/DXT1 unsupported\n");
			return false;
#else
			// status = transcode_slice(pData, data_size, slice_index_to_decode, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBC1, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pData, data_len, block_format::cBC1, bytes_per_block_or_pixel, true, is_video, is_alpha_slice, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to BC1 failed\n");
			}
			break;
#endif
		}
		case transcoder_texture_format::cTFBC4_R:
		{
#if !BASISD_SUPPORT_DXT5A
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: BC4/DXT5A unsupported\n");
			return false;
#else
			//status = transcode_slice(pData, data_size, slice_index_to_decode, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBC4, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pData, data_len, block_format::cBC4, bytes_per_block_or_pixel, false, is_video, is_alpha_slice, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to BC4 failed\n");
			}
			break;
#endif
		}
		case transcoder_texture_format::cTFPVRTC1_4_RGB:
		{
#if !BASISD_SUPPORT_PVRTC1
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: PVRTC1 4 unsupported\n");
			return false;
#else
			// output_row_pitch_in_blocks_or_pixels is actually ignored because we're transcoding to PVRTC1. (Print a dev warning if it's != 0?)
			//status = transcode_slice(pData, data_size, slice_index_to_decode, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cPVRTC1_4_RGB, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pData, data_len, block_format::cPVRTC1_4_RGB, bytes_per_block_or_pixel, false, is_video, is_alpha_slice, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to PVRTC1 4 RGB failed\n");
			}
			break;
#endif
		}
		case transcoder_texture_format::cTFPVRTC1_4_RGBA:
		{
#if !BASISD_SUPPORT_PVRTC1
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: PVRTC1 4 unsupported\n");
			return false;
#else
			assert(basis_file_has_alpha_slices);
			assert(alpha_length);

			// Temp buffer to hold alpha block endpoint/selector indices
			basisu::vector<uint32_t> temp_block_indices(total_slice_blocks);

			// First transcode alpha data to temp buffer
			//status = transcode_slice(pData, data_size, slice_index + 1, &temp_block_indices[0], total_slice_blocks, block_format::cIndices, sizeof(uint32_t), decode_flags, pSlice_descs[slice_index].m_num_blocks_x, pState);
			status = transcode_slice(&temp_block_indices[0], num_blocks_x, num_blocks_y, pCompressed_data + alpha_offset, alpha_length, block_format::cIndices, sizeof(uint32_t), false, is_video, true, level_index, orig_width, orig_height, num_blocks_x, pState, false, nullptr, 0, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to PVRTC1 4 RGBA failed (0)\n");
			}
			else
			{
				// output_row_pitch_in_blocks_or_pixels is actually ignored because we're transcoding to PVRTC1. (Print a dev warning if it's != 0?)
				//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cPVRTC1_4_RGBA, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState, &temp_block_indices[0]);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, block_format::cPVRTC1_4_RGBA, bytes_per_block_or_pixel, false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, &temp_block_indices[0], 0, decode_flags);
				if (!status)
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to PVRTC1 4 RGBA failed (1)\n");
				}
			}

			break;
#endif
		}
		case transcoder_texture_format::cTFBC7_RGBA:
		case transcoder_texture_format::cTFBC7_ALT:
		{
#if !BASISD_SUPPORT_BC7_MODE5
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: BC7 unsupported\n");
			return false;
#else
			assert(bytes_per_block_or_pixel == 16);
			// We used to support transcoding just alpha to BC7 - but is that useful at all?

			// First transcode the color slice. The cBC7_M5_COLOR transcoder will output opaque mode 5 blocks.
			//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBC7_M5_COLOR, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, block_format::cBC7_M5_COLOR, bytes_per_block_or_pixel, false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);

			if ((status) && (basis_file_has_alpha_slices))
			{
				// Now transcode the alpha slice. The cBC7_M5_ALPHA transcoder will now change the opaque mode 5 blocks to blocks with alpha.
				//status = transcode_slice(pData, data_size, slice_index + 1, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBC7_M5_ALPHA, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + alpha_offset, alpha_length, block_format::cBC7_M5_ALPHA, bytes_per_block_or_pixel, false, is_video, true, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			}

			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to BC7 failed (0)\n");
			}

			break;
#endif
		}
		case transcoder_texture_format::cTFETC2_RGBA:
		{
#if !BASISD_SUPPORT_ETC2_EAC_A8
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: ETC2 EAC A8 unsupported\n");
			return false;
#else
			assert(bytes_per_block_or_pixel == 16);

			if (basis_file_has_alpha_slices)
			{
				// First decode the alpha data 
				//status = transcode_slice(pData, data_size, slice_index + 1, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cETC2_EAC_A8, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + alpha_offset, alpha_length, block_format::cETC2_EAC_A8, bytes_per_block_or_pixel, false, is_video, true, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			}
			else
			{
				//write_opaque_alpha_blocks(pSlice_descs[slice_index].m_num_blocks_x, pSlice_descs[slice_index].m_num_blocks_y, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cETC2_EAC_A8, 16, output_row_pitch_in_blocks_or_pixels);
				basisu_transcoder::write_opaque_alpha_blocks(num_blocks_x, num_blocks_y, pOutput_blocks, block_format::cETC2_EAC_A8, 16, output_row_pitch_in_blocks_or_pixels);
				status = true;
			}

			if (status)
			{
				// Now decode the color data
				//status = transcode_slice(pData, data_size, slice_index, (uint8_t*)pOutput_blocks + 8, output_blocks_buf_size_in_blocks_or_pixels, block_format::cETC1, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice((uint8_t *)pOutput_blocks + 8, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, block_format::cETC1, bytes_per_block_or_pixel, false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
				if (!status)
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to ETC2 RGB failed\n");
				}
			}
			else
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to ETC2 A failed\n");
			}
			break;
#endif
		}
		case transcoder_texture_format::cTFBC3_RGBA:
		{
#if !BASISD_SUPPORT_DXT1
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: DXT1 unsupported\n");
			return false;
#elif !BASISD_SUPPORT_DXT5A
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: DXT5A unsupported\n");
			return false;
#else
			assert(bytes_per_block_or_pixel == 16);
						
			// First decode the alpha data 
			if (basis_file_has_alpha_slices)
			{
				//status = transcode_slice(pData, data_size, slice_index + 1, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBC4, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + alpha_offset, alpha_length, block_format::cBC4, bytes_per_block_or_pixel, false, is_video, true, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			}
			else
			{
				basisu_transcoder::write_opaque_alpha_blocks(num_blocks_x, num_blocks_y, pOutput_blocks, block_format::cBC4, 16, output_row_pitch_in_blocks_or_pixels);
				status = true;
			}

			if (status)
			{
				// Now decode the color data. Forbid 3 color blocks, which aren't allowed in BC3.
				//status = transcode_slice(pData, data_size, slice_index, (uint8_t*)pOutput_blocks + 8, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBC1, 16, decode_flags | cDecodeFlagsBC1ForbidThreeColorBlocks, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice((uint8_t *)pOutput_blocks + 8, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, block_format::cBC1, bytes_per_block_or_pixel, false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
				if (!status)
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to BC3 RGB failed\n");
				}
			}
			else
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to BC3 A failed\n");
			}

			break;
#endif
		}
		case transcoder_texture_format::cTFBC5_RG:
		{
#if !BASISD_SUPPORT_DXT5A
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: DXT5A unsupported\n");
			return false;
#else
			assert(bytes_per_block_or_pixel == 16);

			//bool transcode_slice(void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y, const uint8_t* pImage_data, uint32_t image_data_size, block_format fmt,
				//	uint32_t output_block_or_pixel_stride_in_bytes, bool bc1_allow_threecolor_blocks, const bool is_video, const bool is_alpha_slice, const uint32_t level_index, const uint32_t orig_width, const uint32_t orig_height, uint32_t output_row_pitch_in_blocks_or_pixels = 0,
				//	basisu_transcoder_state* pState = nullptr, bool astc_transcode_alpha = false, void* pAlpha_blocks = nullptr, uint32_t output_rows_in_pixels = 0);

			// Decode the R data (actually the green channel of the color data slice in the basis file)
			//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBC4, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, block_format::cBC4, bytes_per_block_or_pixel, false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			if (status)
			{
				if (basis_file_has_alpha_slices)
				{
					// Decode the G data (actually the green channel of the alpha data slice in the basis file)
					//status = transcode_slice(pData, data_size, slice_index + 1, (uint8_t*)pOutput_blocks + 8, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBC4, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
					status = transcode_slice((uint8_t *)pOutput_blocks + 8, num_blocks_x, num_blocks_y, pCompressed_data + alpha_offset, alpha_length, block_format::cBC4, bytes_per_block_or_pixel, false, is_video, true, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
					if (!status)
					{
						BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to BC5 1 failed\n");
					}
				}
				else
				{
					basisu_transcoder::write_opaque_alpha_blocks(num_blocks_x, num_blocks_y, (uint8_t*)pOutput_blocks + 8, block_format::cBC4, 16, output_row_pitch_in_blocks_or_pixels);
					status = true;
				}
			}
			else
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to BC5 channel 0 failed\n");
			}
			break;
#endif
		}
		case transcoder_texture_format::cTFASTC_4x4_RGBA:
		{
#if !BASISD_SUPPORT_ASTC
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: ASTC unsupported\n");
			return false;
#else
			assert(bytes_per_block_or_pixel == 16);

			if (basis_file_has_alpha_slices)
			{
				// First decode the alpha data to the output (we're using the output texture as a temp buffer here).
				//status = transcode_slice(pData, data_size, slice_index + 1, (uint8_t*)pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cIndices, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + alpha_offset, alpha_length, block_format::cIndices, bytes_per_block_or_pixel, false, is_video, true, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
				if (status)
				{
					// Now decode the color data and transcode to ASTC. The transcoder function will read the alpha selector data from the output texture as it converts and
					// transcode both the alpha and color data at the same time to ASTC.
					//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cASTC_4x4, 16, decode_flags | cDecodeFlagsOutputHasAlphaIndices, output_row_pitch_in_blocks_or_pixels, pState);
					status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, block_format::cASTC_4x4, bytes_per_block_or_pixel, false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, true, nullptr, output_rows_in_pixels, decode_flags);
				}
			}
			else
				//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cASTC_4x4, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, block_format::cASTC_4x4, bytes_per_block_or_pixel, false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);

			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to ASTC failed (0)\n");
			}

			break;
#endif
		}
		case transcoder_texture_format::cTFATC_RGB:
		{
#if !BASISD_SUPPORT_ATC
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: ATC unsupported\n");
			return false;
#else
			//status = transcode_slice(pData, data_size, slice_index_to_decode, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cATC_RGB, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pData, data_len, block_format::cATC_RGB, bytes_per_block_or_pixel, false, is_video, is_alpha_slice, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to ATC_RGB failed\n");
			}
			break;
#endif
		}
		case transcoder_texture_format::cTFATC_RGBA:
		{
#if !BASISD_SUPPORT_ATC
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: ATC unsupported\n");
			return false;
#elif !BASISD_SUPPORT_DXT5A
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: DXT5A unsupported\n");
			return false;
#else
			assert(bytes_per_block_or_pixel == 16);

			// First decode the alpha data 
			if (basis_file_has_alpha_slices)
			{
				//status = transcode_slice(pData, data_size, slice_index + 1, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBC4, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + alpha_offset, alpha_length, block_format::cBC4, bytes_per_block_or_pixel, false, is_video, true, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			}
			else
			{
				basisu_transcoder::write_opaque_alpha_blocks(num_blocks_x, num_blocks_y, pOutput_blocks, block_format::cBC4, 16, output_row_pitch_in_blocks_or_pixels);
				status = true;
			}

			if (status)
			{
				//status = transcode_slice(pData, data_size, slice_index, (uint8_t*)pOutput_blocks + 8, output_blocks_buf_size_in_blocks_or_pixels, block_format::cATC_RGB, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice((uint8_t *)pOutput_blocks + 8, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, block_format::cATC_RGB, bytes_per_block_or_pixel, false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
				if (!status)
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to ATC RGB failed\n");
				}
			}
			else
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to ATC A failed\n");
			}
			break;
#endif
		}
		case transcoder_texture_format::cTFPVRTC2_4_RGB:
		{
#if !BASISD_SUPPORT_PVRTC2
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: PVRTC2 unsupported\n");
			return false;
#else
			//status = transcode_slice(pData, data_size, slice_index_to_decode, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cPVRTC2_4_RGB, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pData, data_len, block_format::cPVRTC2_4_RGB, bytes_per_block_or_pixel, false, is_video, is_alpha_slice, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to cPVRTC2_4_RGB failed\n");
			}
			break;
#endif
		}
		case transcoder_texture_format::cTFPVRTC2_4_RGBA:
		{
#if !BASISD_SUPPORT_PVRTC2
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: PVRTC2 unsupported\n");
			return false;
#else
			if (basis_file_has_alpha_slices)
			{
				// First decode the alpha data to the output (we're using the output texture as a temp buffer here).
				//status = transcode_slice(pData, data_size, slice_index + 1, (uint8_t*)pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cIndices, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + alpha_offset, alpha_length, block_format::cIndices, bytes_per_block_or_pixel, false, is_video, true, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
				if (!status)
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to failed\n");
				}
				else
				{
					// Now decode the color data and transcode to PVRTC2 RGBA. 
					//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cPVRTC2_4_RGBA, bytes_per_block_or_pixel, decode_flags | cDecodeFlagsOutputHasAlphaIndices, output_row_pitch_in_blocks_or_pixels, pState);
					status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, block_format::cPVRTC2_4_RGBA, bytes_per_block_or_pixel, false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, true, nullptr, output_rows_in_pixels, decode_flags);
				}
			}
			else
				//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cPVRTC2_4_RGB, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, block_format::cPVRTC2_4_RGB, bytes_per_block_or_pixel, false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);

			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to cPVRTC2_4_RGBA failed\n");
			}

			break;
#endif
		}
		case transcoder_texture_format::cTFRGBA32:
		{
			// Raw 32bpp pixels, decoded in the usual raster order (NOT block order) into an image in memory.

			// First decode the alpha data 
			if (basis_file_has_alpha_slices)
				//status = transcode_slice(pData, data_size, slice_index + 1, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cA32, sizeof(uint32_t), decode_flags, output_row_pitch_in_blocks_or_pixels, pState, nullptr, output_rows_in_pixels);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + alpha_offset, alpha_length, block_format::cA32, sizeof(uint32_t), false, is_video, true, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			else
				status = true;

			if (status)
			{
				//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, basis_file_has_alpha_slices ? block_format::cRGB32 : block_format::cRGBA32, sizeof(uint32_t), decode_flags, output_row_pitch_in_blocks_or_pixels, pState, nullptr, output_rows_in_pixels);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, basis_file_has_alpha_slices ? block_format::cRGB32 : block_format::cRGBA32, sizeof(uint32_t), false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
				if (!status)
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to RGBA32 RGB failed\n");
				}
			}
			else
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to RGBA32 A failed\n");
			}

			break;
		}
		case transcoder_texture_format::cTFRGB565:
		case transcoder_texture_format::cTFBGR565:
		{
			// Raw 16bpp pixels, decoded in the usual raster order (NOT block order) into an image in memory.

			//status = transcode_slice(pData, data_size, slice_index_to_decode, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, (fmt == transcoder_texture_format::cTFRGB565) ? block_format::cRGB565 : block_format::cBGR565, sizeof(uint16_t), decode_flags, output_row_pitch_in_blocks_or_pixels, pState, nullptr, output_rows_in_pixels);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pData, data_len, (target_format == transcoder_texture_format::cTFRGB565) ? block_format::cRGB565 : block_format::cBGR565, sizeof(uint16_t), false, is_video, is_alpha_slice, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to RGB565 RGB failed\n");
			}

			break;
		}
		case transcoder_texture_format::cTFRGBA4444:
		{
			// Raw 16bpp pixels, decoded in the usual raster order (NOT block order) into an image in memory.

			// First decode the alpha data 
			if (basis_file_has_alpha_slices)
				//status = transcode_slice(pData, data_size, slice_index + 1, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cRGBA4444_ALPHA, sizeof(uint16_t), decode_flags, output_row_pitch_in_blocks_or_pixels, pState, nullptr, output_rows_in_pixels);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + alpha_offset, alpha_length, block_format::cRGBA4444_ALPHA, sizeof(uint16_t), false, is_video, true, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			else
				status = true;

			if (status)
			{
				//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, basis_file_has_alpha_slices ? block_format::cRGBA4444_COLOR : block_format::cRGBA4444_COLOR_OPAQUE, sizeof(uint16_t), decode_flags, output_row_pitch_in_blocks_or_pixels, pState, nullptr, output_rows_in_pixels);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, basis_file_has_alpha_slices ? block_format::cRGBA4444_COLOR : block_format::cRGBA4444_COLOR_OPAQUE, sizeof(uint16_t), false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
				if (!status)
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to RGBA4444 RGB failed\n");
				}
			}
			else
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to RGBA4444 A failed\n");
			}

			break;
		}
		case transcoder_texture_format::cTFFXT1_RGB:
		{
#if !BASISD_SUPPORT_FXT1
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: FXT1 unsupported\n");
			return false;
#else
			//status = transcode_slice(pData, data_size, slice_index_to_decode, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cFXT1_RGB, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pData, data_len, block_format::cFXT1_RGB, bytes_per_block_or_pixel, false, is_video, is_alpha_slice, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to FXT1_RGB failed\n");
			}
			break;
#endif
		}
		case transcoder_texture_format::cTFETC2_EAC_R11:
		{
#if !BASISD_SUPPORT_ETC2_EAC_RG11
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: EAC_RG11 unsupported\n");
			return false;
#else
			//status = transcode_slice(pData, data_size, slice_index_to_decode, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cETC2_EAC_R11, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pData, data_len, block_format::cETC2_EAC_R11, bytes_per_block_or_pixel, false, is_video, is_alpha_slice, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to ETC2_EAC_R11 failed\n");
			}

			break;
#endif
		}
		case transcoder_texture_format::cTFETC2_EAC_RG11:
		{
#if !BASISD_SUPPORT_ETC2_EAC_RG11
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: EAC_RG11 unsupported\n");
			return false;
#else
			assert(bytes_per_block_or_pixel == 16);

			if (basis_file_has_alpha_slices)
			{
				// First decode the alpha data to G
				//status = transcode_slice(pData, data_size, slice_index + 1, (uint8_t*)pOutput_blocks + 8, output_blocks_buf_size_in_blocks_or_pixels, block_format::cETC2_EAC_R11, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice((uint8_t *)pOutput_blocks + 8, num_blocks_x, num_blocks_y, pCompressed_data + alpha_offset, alpha_length, block_format::cETC2_EAC_R11, bytes_per_block_or_pixel, false, is_video, true, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			}
			else
			{
				basisu_transcoder::write_opaque_alpha_blocks(num_blocks_x, num_blocks_y, (uint8_t*)pOutput_blocks + 8, block_format::cETC2_EAC_R11, 16, output_row_pitch_in_blocks_or_pixels);
				status = true;
			}

			if (status)
			{
				// Now decode the color data to R
				//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cETC2_EAC_R11, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, block_format::cETC2_EAC_R11, bytes_per_block_or_pixel, false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
				if (!status)
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to ETC2_EAC_R11 R failed\n");
				}
			}
			else
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to ETC2_EAC_R11 G failed\n");
			}

			break;
#endif
		}
		default:
		{
			assert(0);
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: Invalid fmt\n");
			break;
		}
		}

		return status;
	}

	//------------------------------------------------------------------------------------------------
	
	basisu_lowlevel_uastc_ldr_4x4_transcoder::basisu_lowlevel_uastc_ldr_4x4_transcoder()
	{
	}

	bool basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_slice(
		void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y, const uint8_t* pImage_data, uint32_t image_data_size, block_format fmt,
        uint32_t output_block_or_pixel_stride_in_bytes, bool bc1_allow_threecolor_blocks, bool has_alpha, 
		const uint32_t orig_width, const uint32_t orig_height, uint32_t output_row_pitch_in_blocks_or_pixels,
		basisu_transcoder_state* pState, uint32_t output_rows_in_pixels, int channel0, int channel1, uint32_t decode_flags)
	{
		BASISU_NOTE_UNUSED(pState);
		BASISU_NOTE_UNUSED(bc1_allow_threecolor_blocks);

		assert(g_transcoder_initialized);
		if (!g_transcoder_initialized)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_slice: Transcoder not globally initialized.\n");
			return false;
		}

#if BASISD_SUPPORT_UASTC
		const uint32_t total_blocks = num_blocks_x * num_blocks_y;

		if (!output_row_pitch_in_blocks_or_pixels)
		{
			if (basis_block_format_is_uncompressed(fmt))
				output_row_pitch_in_blocks_or_pixels = orig_width;
			else
			{
				if (fmt == block_format::cFXT1_RGB)
					output_row_pitch_in_blocks_or_pixels = (orig_width + 7) / 8;
				else
					output_row_pitch_in_blocks_or_pixels = num_blocks_x;
			}
		}

		if (basis_block_format_is_uncompressed(fmt))
		{
			if (!output_rows_in_pixels)
				output_rows_in_pixels = orig_height;
		}

		uint32_t total_expected_block_bytes = sizeof(uastc_block) * total_blocks;
		if (image_data_size < total_expected_block_bytes)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_slice: image_data_size < total_expected_block_bytes The file is corrupted or this is a bug.\n");
			return false;
		}

		const uastc_block* pSource_block = reinterpret_cast<const uastc_block *>(pImage_data);

		const bool high_quality = (decode_flags & cDecodeFlagsHighQuality) != 0;
		const bool from_alpha = has_alpha && (decode_flags & cDecodeFlagsTranscodeAlphaDataToOpaqueFormats) != 0;

		bool status = false;
		if ((fmt == block_format::cPVRTC1_4_RGB) || (fmt == block_format::cPVRTC1_4_RGBA))
		{
			if (fmt == block_format::cPVRTC1_4_RGBA)
				transcode_uastc_to_pvrtc1_4_rgba((const uastc_block*)pImage_data, pDst_blocks, num_blocks_x, num_blocks_y, high_quality);
			else
				transcode_uastc_to_pvrtc1_4_rgb((const uastc_block *)pImage_data, pDst_blocks, num_blocks_x, num_blocks_y, high_quality, from_alpha);
		}
		else
		{
			for (uint32_t block_y = 0; block_y < num_blocks_y; ++block_y)
			{
				void* pDst_block = (uint8_t*)pDst_blocks + block_y * output_row_pitch_in_blocks_or_pixels * output_block_or_pixel_stride_in_bytes;
								
				for (uint32_t block_x = 0; block_x < num_blocks_x; ++block_x, ++pSource_block, pDst_block = (uint8_t *)pDst_block + output_block_or_pixel_stride_in_bytes)
				{
					switch (fmt)
					{
					case block_format::cUASTC_4x4:
					{
						memcpy(pDst_block, pSource_block, sizeof(uastc_block));
						status = true;
						break;
					}
					case block_format::cETC1:
					{
						if (from_alpha)
							status = transcode_uastc_to_etc1(*pSource_block, pDst_block, 3);
						else
							status = transcode_uastc_to_etc1(*pSource_block, pDst_block);
						break;
					}
					case block_format::cETC2_RGBA:
					{
						status = transcode_uastc_to_etc2_rgba(*pSource_block, pDst_block);
						break;
					}
					case block_format::cBC1:
					{
						status = transcode_uastc_to_bc1(*pSource_block, pDst_block, high_quality);
						break;
					}
					case block_format::cBC3:
					{
						status = transcode_uastc_to_bc3(*pSource_block, pDst_block, high_quality);
						break;
					}
					case block_format::cBC4:
					{
						if (channel0 < 0) 
							channel0 = 0;
						status = transcode_uastc_to_bc4(*pSource_block, pDst_block, high_quality, channel0);
						break;
					}
					case block_format::cBC5:
					{
						if (channel0 < 0)
							channel0 = 0;
						if (channel1 < 0)
							channel1 = 3;
						status = transcode_uastc_to_bc5(*pSource_block, pDst_block, high_quality, channel0, channel1);
						break;
					}
					case block_format::cBC7:
					case block_format::cBC7_M5_COLOR: // for consistently with ETC1S
					{
						status = transcode_uastc_to_bc7(*pSource_block, pDst_block);
						break;
					}
					case block_format::cASTC_4x4:
					{
						status = transcode_uastc_to_astc(*pSource_block, pDst_block);
						break;
					}
					case block_format::cETC2_EAC_R11:
					{
						if (channel0 < 0)
							channel0 = 0;
						status = transcode_uastc_to_etc2_eac_r11(*pSource_block, pDst_block, high_quality, channel0);
						break;
					}
					case block_format::cETC2_EAC_RG11:
					{
						if (channel0 < 0)
							channel0 = 0;
						if (channel1 < 0)
							channel1 = 3;
						status = transcode_uastc_to_etc2_eac_rg11(*pSource_block, pDst_block, high_quality, channel0, channel1);
						break;
					}
					case block_format::cRGBA32:
					{
						color32 block_pixels[4][4];
						status = unpack_uastc(*pSource_block, (color32 *)block_pixels, false);

						assert(sizeof(uint32_t) == output_block_or_pixel_stride_in_bytes);
						uint8_t* pDst_pixels = static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint32_t);

						const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
						const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

						for (uint32_t y = 0; y < max_y; y++)
						{
							for (uint32_t x = 0; x < max_x; x++)
							{
								const color32& c = block_pixels[y][x];

								pDst_pixels[0 + 4 * x] = c.r;
								pDst_pixels[1 + 4 * x] = c.g;
								pDst_pixels[2 + 4 * x] = c.b;
								pDst_pixels[3 + 4 * x] = c.a;
							}

							pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint32_t);
						}

						break;
					}
					case block_format::cRGB565:
					case block_format::cBGR565:
					{
						color32 block_pixels[4][4];
						status = unpack_uastc(*pSource_block, (color32*)block_pixels, false);

						assert(sizeof(uint16_t) == output_block_or_pixel_stride_in_bytes);
						uint8_t* pDst_pixels = static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint16_t);

						const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
						const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

						for (uint32_t y = 0; y < max_y; y++)
						{
							for (uint32_t x = 0; x < max_x; x++)
							{
								const color32& c = block_pixels[y][x];

								const uint16_t packed = (fmt == block_format::cRGB565) ? static_cast<uint16_t>((mul_8(c.r, 31) << 11) | (mul_8(c.g, 63) << 5) | mul_8(c.b, 31)) :
									static_cast<uint16_t>((mul_8(c.b, 31) << 11) | (mul_8(c.g, 63) << 5) | mul_8(c.r, 31));

								pDst_pixels[x * 2 + 0] = (uint8_t)(packed & 0xFF);
								pDst_pixels[x * 2 + 1] = (uint8_t)((packed >> 8) & 0xFF);
							}

							pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint16_t);
						}

						break;
					}
					case block_format::cRGBA4444:
					{
						color32 block_pixels[4][4];
						status = unpack_uastc(*pSource_block, (color32*)block_pixels, false);

						assert(sizeof(uint16_t) == output_block_or_pixel_stride_in_bytes);
						uint8_t* pDst_pixels = static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint16_t);

						const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
						const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

						for (uint32_t y = 0; y < max_y; y++)
						{
							for (uint32_t x = 0; x < max_x; x++)
							{
								const color32& c = block_pixels[y][x];

								const uint16_t packed = static_cast<uint16_t>((mul_8(c.r, 15) << 12) | (mul_8(c.g, 15) << 8) | (mul_8(c.b, 15) << 4) | mul_8(c.a, 15));

								pDst_pixels[x * 2 + 0] = (uint8_t)(packed & 0xFF);
								pDst_pixels[x * 2 + 1] = (uint8_t)((packed >> 8) & 0xFF);
							}

							pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint16_t);
						}
						break;
					}
					default:
						assert(0);
						break;

					}

					if (!status)
					{
						BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_slice: Transcoder failed to unpack a UASTC block - this is a bug, or the data was corrupted\n");
						return false;
					}

				} // block_x

			} // block_y
		}

		return true;
#else
		BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_slice: UASTC is unsupported\n");

		BASISU_NOTE_UNUSED(decode_flags);
		BASISU_NOTE_UNUSED(channel0);
		BASISU_NOTE_UNUSED(channel1);
		BASISU_NOTE_UNUSED(output_rows_in_pixels);
		BASISU_NOTE_UNUSED(output_row_pitch_in_blocks_or_pixels);
		BASISU_NOTE_UNUSED(output_block_or_pixel_stride_in_bytes);
		BASISU_NOTE_UNUSED(fmt);
		BASISU_NOTE_UNUSED(image_data_size);
		BASISU_NOTE_UNUSED(pImage_data);
		BASISU_NOTE_UNUSED(num_blocks_x);
		BASISU_NOTE_UNUSED(num_blocks_y);
		BASISU_NOTE_UNUSED(pDst_blocks);

		return false;
#endif
	}
		
	bool basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image(
		transcoder_texture_format target_format,
		void* pOutput_blocks, uint32_t output_blocks_buf_size_in_blocks_or_pixels,
		const uint8_t* pCompressed_data, uint32_t compressed_data_length,
		uint32_t num_blocks_x, uint32_t num_blocks_y, uint32_t orig_width, uint32_t orig_height, uint32_t level_index,
		uint64_t slice_offset, uint32_t slice_length,
		uint32_t decode_flags,
		bool has_alpha,
		bool is_video,
		uint32_t output_row_pitch_in_blocks_or_pixels,
		basisu_transcoder_state* pState,
		uint32_t output_rows_in_pixels,
		int channel0, int channel1)
	{
		BASISU_NOTE_UNUSED(is_video);
		BASISU_NOTE_UNUSED(level_index);

		if (((uint64_t)slice_offset + slice_length) > (uint64_t)compressed_data_length)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: source data buffer too small\n");
			return false;
		}	

		if ((target_format == transcoder_texture_format::cTFPVRTC1_4_RGB) || (target_format == transcoder_texture_format::cTFPVRTC1_4_RGBA))
		{
			if ((!basisu::is_pow2(num_blocks_x * 4)) || (!basisu::is_pow2(num_blocks_y * 4)))
			{
				// PVRTC1 only supports power of 2 dimensions
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: PVRTC1 only supports power of 2 dimensions\n");
				return false;
			}
		}

		if ((target_format == transcoder_texture_format::cTFPVRTC1_4_RGBA) && (!has_alpha))
		{
			// Switch to PVRTC1 RGB if the input doesn't have alpha.
			target_format = transcoder_texture_format::cTFPVRTC1_4_RGB;
		}

		const bool transcode_alpha_data_to_opaque_formats = (decode_flags & cDecodeFlagsTranscodeAlphaDataToOpaqueFormats) != 0;
		const uint32_t bytes_per_block_or_pixel = basis_get_bytes_per_block_or_pixel(target_format);
		//const uint32_t total_slice_blocks = num_blocks_x * num_blocks_y;

		if (!basis_validate_output_buffer_size(basis_tex_format::cUASTC4x4, target_format, output_blocks_buf_size_in_blocks_or_pixels, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, output_rows_in_pixels))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: output buffer size too small\n");
			return false;
		}
				
		bool status = false;

		// UASTC4x4
		switch (target_format)
		{
		case transcoder_texture_format::cTFETC1_RGB:
		{
			//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cETC1, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cETC1,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
				
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to ETC1 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFETC2_RGBA:
		{
			//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cETC2_RGBA, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cETC2_RGBA,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to ETC2 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFBC1_RGB:
		{
			// TODO: ETC1S allows BC1 from alpha channel. That doesn't seem actually useful, though.
			//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBC1, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC1,
				bytes_per_block_or_pixel, true, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to BC1 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFBC3_RGBA:
		{
			//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBC3, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC3,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to BC3 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFBC4_R:
		{
			//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBC4, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState,
			//	nullptr, 0,
			//	((has_alpha) && (transcode_alpha_data_to_opaque_formats)) ? 3 : 0);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC4,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels,
				((has_alpha) && (transcode_alpha_data_to_opaque_formats)) ? 3 : 0, -1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to BC4 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFBC5_RG:
		{
			//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBC5, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState,
			//	nullptr, 0,
			//	0, 3);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC5,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels,
				0, 3, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to BC5 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFBC7_RGBA:
		case transcoder_texture_format::cTFBC7_ALT:
		{
			//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBC7, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC7,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to BC7 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFPVRTC1_4_RGB:
		{
			//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cPVRTC1_4_RGB, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cPVRTC1_4_RGB,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to PVRTC1 RGB 4bpp failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFPVRTC1_4_RGBA:
		{
			//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cPVRTC1_4_RGBA, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cPVRTC1_4_RGBA,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to PVRTC1 RGBA 4bpp failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFASTC_4x4_RGBA:
		{
			//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cASTC_4x4, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cASTC_4x4,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to ASTC 4x4 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFATC_RGB:
		case transcoder_texture_format::cTFATC_RGBA:
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: UASTC->ATC currently unsupported\n");
			return false;
		}
		case transcoder_texture_format::cTFFXT1_RGB:
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: UASTC->FXT1 currently unsupported\n");
			return false;
		}
		case transcoder_texture_format::cTFPVRTC2_4_RGB:
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: UASTC->PVRTC2 currently unsupported\n");
			return false;
		}
		case transcoder_texture_format::cTFPVRTC2_4_RGBA:
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: UASTC->PVRTC2 currently unsupported\n");
			return false;
		}
		case transcoder_texture_format::cTFETC2_EAC_R11:
		{
			//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cETC2_EAC_R11, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState,
			//	nullptr, 0,
			//	((has_alpha) && (transcode_alpha_data_to_opaque_formats)) ? 3 : 0);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cETC2_EAC_R11,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels,
				((has_alpha) && (transcode_alpha_data_to_opaque_formats)) ? 3 : 0, -1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to EAC R11 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFETC2_EAC_RG11:
		{
			//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cETC2_EAC_RG11, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState,
			//	nullptr, 0,
			//	0, 3);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cETC2_EAC_RG11,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels,
				0, 3, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_basisu_lowlevel_uastc_ldr_4x4_transcodertranscoder::transcode_image: transcode_slice() to EAC RG11 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGBA32:
		{
			//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cRGBA32, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGBA32,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to RGBA32 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGB565:
		{
			//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cRGB565, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGB565,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to RGB565 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFBGR565:
		{
			//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBGR565, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBGR565,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to RGB565 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGBA4444:
		{
			//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cRGBA4444, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGBA4444,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to RGBA4444 failed\n");
			}
			break;
		}
		default:
		{
			assert(0);
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: Invalid format\n");
			break;
		}
		}

		return status;
	}

	//------------------------------------------------------------------------------------------------
	// UASTC HDR 4x4

	basisu_lowlevel_uastc_hdr_4x4_transcoder::basisu_lowlevel_uastc_hdr_4x4_transcoder()
	{
	}

	bool basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_slice(
		void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y, const uint8_t* pImage_data, uint32_t image_data_size, block_format fmt,
		uint32_t output_block_or_pixel_stride_in_bytes, bool bc1_allow_threecolor_blocks, bool has_alpha, 
		const uint32_t orig_width, const uint32_t orig_height, uint32_t output_row_pitch_in_blocks_or_pixels,
		basisu_transcoder_state* pState, uint32_t output_rows_in_pixels, int channel0, int channel1, uint32_t decode_flags)
	{
		BASISU_NOTE_UNUSED(pState);
		BASISU_NOTE_UNUSED(bc1_allow_threecolor_blocks);
		BASISU_NOTE_UNUSED(has_alpha);
		BASISU_NOTE_UNUSED(channel0);
		BASISU_NOTE_UNUSED(channel1);
		BASISU_NOTE_UNUSED(decode_flags);
		BASISU_NOTE_UNUSED(orig_width);
		BASISU_NOTE_UNUSED(orig_height);

		assert(g_transcoder_initialized);
		if (!g_transcoder_initialized)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_slice: Transcoder not globally initialized.\n");
			return false;
		}

#if BASISD_SUPPORT_UASTC_HDR
		const uint32_t total_blocks = num_blocks_x * num_blocks_y;

		if (!output_row_pitch_in_blocks_or_pixels)
		{
			if (basis_block_format_is_uncompressed(fmt))
				output_row_pitch_in_blocks_or_pixels = orig_width;
			else
				output_row_pitch_in_blocks_or_pixels = num_blocks_x;
		}

		if (basis_block_format_is_uncompressed(fmt))
		{
			if (!output_rows_in_pixels)
				output_rows_in_pixels = orig_height;
		}

		uint32_t total_expected_block_bytes = sizeof(astc_blk) * total_blocks;
		if (image_data_size < total_expected_block_bytes)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_slice: image_data_size < total_expected_block_bytes The file is corrupted or this is a bug.\n");
			return false;
		}

		const astc_blk* pSource_block = reinterpret_cast<const astc_blk*>(pImage_data);

		bool status = false;

		// TODO: Optimize pure memcpy() case.
			
		for (uint32_t block_y = 0; block_y < num_blocks_y; ++block_y)
		{
			void* pDst_block = (uint8_t*)pDst_blocks + block_y * output_row_pitch_in_blocks_or_pixels * output_block_or_pixel_stride_in_bytes;

			for (uint32_t block_x = 0; block_x < num_blocks_x; ++block_x, ++pSource_block, pDst_block = (uint8_t*)pDst_block + output_block_or_pixel_stride_in_bytes)
			{
				switch (fmt)
				{
				case block_format::cUASTC_HDR_4x4:
				case block_format::cASTC_HDR_4x4:
				{
					// Nothing to do, UASTC HDR 4x4 is just ASTC.
					memcpy(pDst_block, pSource_block, sizeof(uastc_block));
					status = true;
					break;
				}
				case block_format::cBC6H:
				{
					status = astc_hdr_transcode_to_bc6h(*pSource_block, *(bc6h_block *)pDst_block);
					break;
				}
				case block_format::cRGB_9E5:
				{
					astc_helpers::log_astc_block log_blk;
					status = astc_helpers::unpack_block(pSource_block, log_blk, 4, 4);
					if (status)
					{
						uint32_t* pDst_pixels = reinterpret_cast<uint32_t*>(
							static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint32_t)
							);

						uint32_t blk_texels[4][4];

						status = astc_helpers::decode_block(log_blk, blk_texels, 4, 4, astc_helpers::cDecodeModeRGB9E5);
						
						if (status)
						{
							const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
							const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

							for (uint32_t y = 0; y < max_y; y++)
							{
								memcpy(pDst_pixels, &blk_texels[y][0], sizeof(uint32_t) * max_x);

								pDst_pixels += output_row_pitch_in_blocks_or_pixels;
							} // y
						}
					}
					
					break;
				}
				case block_format::cRGBA_HALF:
				{
					astc_helpers::log_astc_block log_blk;
					status = astc_helpers::unpack_block(pSource_block, log_blk, 4, 4);
					if (status)
					{
						half_float* pDst_pixels = reinterpret_cast<half_float*>(
							static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(half_float) * 4
							);
												
						half_float blk_texels[4][4][4];
						status = astc_helpers::decode_block(log_blk, blk_texels, 4, 4, astc_helpers::cDecodeModeHDR16);

						if (status)
						{
							const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
							const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

							for (uint32_t y = 0; y < max_y; y++)
							{
								for (uint32_t x = 0; x < max_x; x++)
								{
									pDst_pixels[0 + 4 * x] = blk_texels[y][x][0];
									pDst_pixels[1 + 4 * x] = blk_texels[y][x][1];
									pDst_pixels[2 + 4 * x] = blk_texels[y][x][2];
									pDst_pixels[3 + 4 * x] = blk_texels[y][x][3];
								} // x

								pDst_pixels += output_row_pitch_in_blocks_or_pixels * 4;
							} // y
						}
					}

					break;
				}
				case block_format::cRGB_HALF:
				{
					astc_helpers:: log_astc_block log_blk;
					status = astc_helpers::unpack_block(pSource_block, log_blk, 4, 4);
					if (status)
					{
						half_float* pDst_pixels =
							reinterpret_cast<half_float*>(static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(half_float) * 3);

						half_float blk_texels[4][4][4];
						status = astc_helpers::decode_block(log_blk, blk_texels, 4, 4, astc_helpers::cDecodeModeHDR16);
						if (status)
						{
							const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
							const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

							for (uint32_t y = 0; y < max_y; y++)
							{
								for (uint32_t x = 0; x < max_x; x++)
								{
									pDst_pixels[0 + 3 * x] = blk_texels[y][x][0];
									pDst_pixels[1 + 3 * x] = blk_texels[y][x][1];
									pDst_pixels[2 + 3 * x] = blk_texels[y][x][2];
								} // x

								pDst_pixels += output_row_pitch_in_blocks_or_pixels * 3;
							} // y
						}
					}

					break;
				}
				default:
					assert(0);
					break;

				}

				if (!status)
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_slice: Transcoder failed to unpack a UASTC HDR block - this is a bug, or the data was corrupted\n");					
					return false;
				}

			} // block_x

		} // block_y

		return true;
#else
		BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_slice: UASTC_HDR is unsupported\n");

		BASISU_NOTE_UNUSED(decode_flags);
		BASISU_NOTE_UNUSED(channel0);
		BASISU_NOTE_UNUSED(channel1);
		BASISU_NOTE_UNUSED(output_rows_in_pixels);
		BASISU_NOTE_UNUSED(output_row_pitch_in_blocks_or_pixels);
		BASISU_NOTE_UNUSED(output_block_or_pixel_stride_in_bytes);
		BASISU_NOTE_UNUSED(fmt);
		BASISU_NOTE_UNUSED(image_data_size);
		BASISU_NOTE_UNUSED(pImage_data);
		BASISU_NOTE_UNUSED(num_blocks_x);
		BASISU_NOTE_UNUSED(num_blocks_y);
		BASISU_NOTE_UNUSED(pDst_blocks);

		return false;
#endif
	}

	bool basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_image(
		transcoder_texture_format target_format,
		void* pOutput_blocks, uint32_t output_blocks_buf_size_in_blocks_or_pixels,
		const uint8_t* pCompressed_data, uint32_t compressed_data_length,
		uint32_t num_blocks_x, uint32_t num_blocks_y, uint32_t orig_width, uint32_t orig_height, uint32_t level_index,
		uint64_t slice_offset, uint32_t slice_length,
		uint32_t decode_flags,
		bool has_alpha,
		bool is_video,
		uint32_t output_row_pitch_in_blocks_or_pixels,
		basisu_transcoder_state* pState,
		uint32_t output_rows_in_pixels,
		int channel0, int channel1)
	{
		BASISU_NOTE_UNUSED(is_video);
		BASISU_NOTE_UNUSED(level_index);
		BASISU_NOTE_UNUSED(decode_flags);

		if (((uint64_t)slice_offset + slice_length) > (uint64_t)compressed_data_length)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_image: source data buffer too small\n");
			return false;
		}

		const uint32_t bytes_per_block_or_pixel = basis_get_bytes_per_block_or_pixel(target_format);
		//const uint32_t total_slice_blocks = num_blocks_x * num_blocks_y;

		if (!basis_validate_output_buffer_size(basis_tex_format::cUASTC_HDR_4x4, target_format, output_blocks_buf_size_in_blocks_or_pixels, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, output_rows_in_pixels))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_image: output buffer size too small\n");
			return false;
		}

		bool status = false;

		switch (target_format)
		{
		case transcoder_texture_format::cTFASTC_HDR_4x4_RGBA:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cASTC_HDR_4x4,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);

			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_image: transcode_slice() to ASTC_HDR failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFBC6H:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC6H,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_image: transcode_slice() to BC6H failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGB_HALF:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGB_HALF,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_image: transcode_slice() to RGB_HALF failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGBA_HALF:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGBA_HALF,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_image: transcode_slice() to RGBA_HALF failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGB_9E5:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGB_9E5,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_image: transcode_slice() to RGBA_HALF failed\n");
			}
			break;
		}
		default:
		{
			assert(0);
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_image: Invalid format\n");
			break;
		}
		}

		return status;
	}

	//------------------------------------------------------------------------------------------------
	// ASTC 6x6 HDR

	basisu_lowlevel_astc_hdr_6x6_transcoder::basisu_lowlevel_astc_hdr_6x6_transcoder()
	{
	}

	// num_blocks_x/num_blocks_y are source 6x6 blocks
	bool basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_slice(
		void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y, const uint8_t* pImage_data, uint32_t image_data_size, block_format fmt,
		uint32_t output_block_or_pixel_stride_in_bytes, bool bc1_allow_threecolor_blocks, bool has_alpha,
		const uint32_t orig_width, const uint32_t orig_height, uint32_t output_row_pitch_in_blocks_or_pixels,
		basisu_transcoder_state* pState, uint32_t output_rows_in_pixels, int channel0, int channel1, uint32_t decode_flags)
	{
		BASISU_NOTE_UNUSED(pState);
		BASISU_NOTE_UNUSED(bc1_allow_threecolor_blocks);
		BASISU_NOTE_UNUSED(has_alpha);
		BASISU_NOTE_UNUSED(channel0);
		BASISU_NOTE_UNUSED(channel1);
		BASISU_NOTE_UNUSED(decode_flags);
		BASISU_NOTE_UNUSED(orig_width);
		BASISU_NOTE_UNUSED(orig_height);

		assert(g_transcoder_initialized);
		if (!g_transcoder_initialized)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_slice: Transcoder not globally initialized.\n");
			return false;
		}

#if BASISD_SUPPORT_UASTC_HDR
		const uint32_t total_src_blocks = num_blocks_x * num_blocks_y;

		const uint32_t output_block_width = get_block_width(fmt);
		//const uint32_t output_block_height = get_block_height(fmt);

		if (!output_row_pitch_in_blocks_or_pixels)
		{
			if (basis_block_format_is_uncompressed(fmt))
				output_row_pitch_in_blocks_or_pixels = orig_width;
			else
				output_row_pitch_in_blocks_or_pixels = (orig_width + output_block_width - 1) / output_block_width;
		}

		if (basis_block_format_is_uncompressed(fmt))
		{
			if (!output_rows_in_pixels)
				output_rows_in_pixels = orig_height;
		}

		uint32_t total_expected_block_bytes = sizeof(astc_blk) * total_src_blocks;
		if (image_data_size < total_expected_block_bytes)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_slice: image_data_size < total_expected_block_bytes The file is corrupted or this is a bug.\n");
			return false;
		}

		const astc_blk* pSource_block = reinterpret_cast<const astc_blk*>(pImage_data);

		bool status = false;

		half_float unpacked_blocks[12][12][3]; // [y][x][c]

		assert(((orig_width + 5) / 6) == num_blocks_x);
		assert(((orig_height + 5) / 6) == num_blocks_y);
				
		if (fmt == block_format::cBC6H)
		{
			const uint32_t num_dst_blocks_x = (orig_width + 3) / 4;
			const uint32_t num_dst_blocks_y = (orig_height + 3) / 4;

			if (!output_row_pitch_in_blocks_or_pixels)
			{
				output_row_pitch_in_blocks_or_pixels = num_dst_blocks_x;
			}
			else if (output_row_pitch_in_blocks_or_pixels < num_dst_blocks_x)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_slice: output_row_pitch_in_blocks_or_pixels is too low\n");
				return false;
			}

			if (output_block_or_pixel_stride_in_bytes != sizeof(bc6h_block))
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_slice: invalid output_block_or_pixel_stride_in_bytes\n");
				return false;
			}

			fast_bc6h_params bc6h_enc_params;
			const bool hq_flag = (decode_flags & cDecodeFlagsHighQuality) != 0;
			bc6h_enc_params.m_max_2subset_pats_to_try = hq_flag ? 1 : 0;
						
			for (uint32_t src_block_y = 0; src_block_y < num_blocks_y; src_block_y += 2)
			{
				const uint32_t num_inner_blocks_y = basisu::minimum<uint32_t>(2, num_blocks_y - src_block_y);

				for (uint32_t src_block_x = 0; src_block_x < num_blocks_x; src_block_x += 2)
				{
					const uint32_t num_inner_blocks_x = basisu::minimum<uint32_t>(2, num_blocks_x - src_block_x);

					for (uint32_t iy = 0; iy < num_inner_blocks_y; iy++)
					{
						for (uint32_t ix = 0; ix < num_inner_blocks_x; ix++)
						{
							const astc_blk* pS = pSource_block + (src_block_y + iy) * num_blocks_x + (src_block_x + ix);

							half_float blk_texels[6][6][4];
							
							astc_helpers::log_astc_block log_blk;
							status = astc_helpers::unpack_block(pS, log_blk, 6, 6);
							if (!status)
							{
								BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_slice: Transcoder failed to unpack a ASTC HDR block - this is a bug, or the data was corrupted\n");
								return false;
							}
							
							status = astc_helpers::decode_block(log_blk, blk_texels, 6, 6, astc_helpers::cDecodeModeHDR16);
							if (!status)
							{
								BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_slice: Transcoder failed to unpack a ASTC HDR block - this is a bug, or the data was corrupted\n");
								return false;
							}

							for (uint32_t y = 0; y < 6; y++)
							{
								for (uint32_t x = 0; x < 6; x++)
								{
									unpacked_blocks[iy * 6 + y][ix * 6 + x][0] = blk_texels[y][x][0];
									unpacked_blocks[iy * 6 + y][ix * 6 + x][1] = blk_texels[y][x][1];
									unpacked_blocks[iy * 6 + y][ix * 6 + x][2] = blk_texels[y][x][2];
																		
								} // x
							} // y

						} // ix

					} // iy
	
					const uint32_t dst_x = src_block_x * 6;
					assert((dst_x & 3) == 0);
					const uint32_t dst_block_x = dst_x >> 2;

					const uint32_t dst_y = src_block_y * 6;
					assert((dst_y & 3) == 0);
					const uint32_t dst_block_y = dst_y >> 2;

					const uint32_t num_inner_dst_blocks_x = basisu::minimum<uint32_t>(3, num_dst_blocks_x - dst_block_x);
					const uint32_t num_inner_dst_blocks_y = basisu::minimum<uint32_t>(3, num_dst_blocks_y - dst_block_y);

					for (uint32_t dy = 0; dy < num_inner_dst_blocks_y; dy++)
					{
						for (uint32_t dx = 0; dx < num_inner_dst_blocks_x; dx++)
						{
							bc6h_block* pDst_block = (bc6h_block*)pDst_blocks + (dst_block_x + dx) + (dst_block_y + dy) * output_row_pitch_in_blocks_or_pixels;

							half_float src_pixels[4][4][3]; // [y][x][c]

							for (uint32_t y = 0; y < 4; y++)
							{
								const uint32_t src_pixel_y = basisu::minimum<uint32_t>(dy * 4 + y, num_inner_blocks_y * 6 - 1);

								for (uint32_t x = 0; x < 4; x++)
								{
									const uint32_t src_pixel_x = basisu::minimum<uint32_t>(dx * 4 + x, num_inner_blocks_x * 6 - 1);

									assert((src_pixel_y < 12) && (src_pixel_x < 12));

									src_pixels[y][x][0] = unpacked_blocks[src_pixel_y][src_pixel_x][0];
									src_pixels[y][x][1] = unpacked_blocks[src_pixel_y][src_pixel_x][1];
									src_pixels[y][x][2] = unpacked_blocks[src_pixel_y][src_pixel_x][2];
									
								} // x
							} // y
							
							astc_6x6_hdr::fast_encode_bc6h(&src_pixels[0][0][0], pDst_block, bc6h_enc_params);

						} // dx
					} // dy

				} // block_x

			} // block_y
						
			status = true;
		}
		else
		{
			for (uint32_t block_y = 0; block_y < num_blocks_y; ++block_y)
			{
				void* pDst_block = (uint8_t*)pDst_blocks + block_y * output_row_pitch_in_blocks_or_pixels * output_block_or_pixel_stride_in_bytes;

				for (uint32_t block_x = 0; block_x < num_blocks_x; ++block_x, ++pSource_block, pDst_block = (uint8_t*)pDst_block + output_block_or_pixel_stride_in_bytes)
				{
					switch (fmt)
					{
					case block_format::cASTC_HDR_6x6:
					{
						// Nothing to do, ASTC HDR 6x6 is just ASTC.
						// TODO: Optimize this copy
						memcpy(pDst_block, pSource_block, sizeof(astc_helpers::astc_block));
						status = true;
						break;
					}
					case block_format::cRGB_9E5:
					{
						astc_helpers::log_astc_block log_blk;
						status = astc_helpers::unpack_block(pSource_block, log_blk, 6, 6);
						if (status)
						{
							uint32_t* pDst_pixels = reinterpret_cast<uint32_t*>(
								static_cast<uint8_t*>(pDst_blocks) + (block_x * 6 + block_y * 6 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint32_t)
								);

							uint32_t blk_texels[6][6];

							status = astc_helpers::decode_block(log_blk, blk_texels, 6, 6, astc_helpers::cDecodeModeRGB9E5);

							if (status)
							{
								const uint32_t max_x = basisu::minimum<int>(6, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 6);
								const uint32_t max_y = basisu::minimum<int>(6, (int)output_rows_in_pixels - (int)block_y * 6);

								for (uint32_t y = 0; y < max_y; y++)
								{
									memcpy(pDst_pixels, &blk_texels[y][0], sizeof(uint32_t) * max_x);

									pDst_pixels += output_row_pitch_in_blocks_or_pixels;
								} // y
							}
						}

						break;
					}
					case block_format::cRGBA_HALF:
					{
						astc_helpers::log_astc_block log_blk;
						status = astc_helpers::unpack_block(pSource_block, log_blk, 6, 6);
						if (status)
						{
							half_float* pDst_pixels = reinterpret_cast<half_float*>(
								static_cast<uint8_t*>(pDst_blocks) + (block_x * 6 + block_y * 6 * output_row_pitch_in_blocks_or_pixels) * sizeof(half_float) * 4
								);

							half_float blk_texels[6][6][4];
							status = astc_helpers::decode_block(log_blk, blk_texels, 6, 6, astc_helpers::cDecodeModeHDR16);

							if (status)
							{
								const uint32_t max_x = basisu::minimum<int>(6, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 6);
								const uint32_t max_y = basisu::minimum<int>(6, (int)output_rows_in_pixels - (int)block_y * 6);

								for (uint32_t y = 0; y < max_y; y++)
								{
									for (uint32_t x = 0; x < max_x; x++)
									{
										pDst_pixels[0 + 4 * x] = blk_texels[y][x][0];
										pDst_pixels[1 + 4 * x] = blk_texels[y][x][1];
										pDst_pixels[2 + 4 * x] = blk_texels[y][x][2];
										pDst_pixels[3 + 4 * x] = blk_texels[y][x][3];
									} // x

									pDst_pixels += output_row_pitch_in_blocks_or_pixels * 4;
								} // y
							}
						}

						break;
					}
					case block_format::cRGB_HALF:
					{
						astc_helpers::log_astc_block log_blk;
						status = astc_helpers::unpack_block(pSource_block, log_blk, 6, 6);
						if (status)
						{
							half_float* pDst_pixels =
								reinterpret_cast<half_float*>(static_cast<uint8_t*>(pDst_blocks) + (block_x * 6 + block_y * 6 * output_row_pitch_in_blocks_or_pixels) * sizeof(half_float) * 3);

							half_float blk_texels[6][6][4];
							status = astc_helpers::decode_block(log_blk, blk_texels, 6, 6, astc_helpers::cDecodeModeHDR16);
							if (status)
							{
								const uint32_t max_x = basisu::minimum<int>(6, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 6);
								const uint32_t max_y = basisu::minimum<int>(6, (int)output_rows_in_pixels - (int)block_y * 6);

								for (uint32_t y = 0; y < max_y; y++)
								{
									for (uint32_t x = 0; x < max_x; x++)
									{
										pDst_pixels[0 + 3 * x] = blk_texels[y][x][0];
										pDst_pixels[1 + 3 * x] = blk_texels[y][x][1];
										pDst_pixels[2 + 3 * x] = blk_texels[y][x][2];
									} // x

									pDst_pixels += output_row_pitch_in_blocks_or_pixels * 3;
								} // y
							}
						}

						break;
					}
					default:
						assert(0);
						break;

					}

					if (!status)
					{
						BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_slice: Transcoder failed to unpack a ASTC HDR block - this is a bug, or the data was corrupted\n");					
						return false;
					}

				} // block_x

			} // block_y
		}

		return true;
#else
		BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_slice: ASTC HDR is unsupported\n");

		BASISU_NOTE_UNUSED(decode_flags);
		BASISU_NOTE_UNUSED(channel0);
		BASISU_NOTE_UNUSED(channel1);
		BASISU_NOTE_UNUSED(output_rows_in_pixels);
		BASISU_NOTE_UNUSED(output_row_pitch_in_blocks_or_pixels);
		BASISU_NOTE_UNUSED(output_block_or_pixel_stride_in_bytes);
		BASISU_NOTE_UNUSED(fmt);
		BASISU_NOTE_UNUSED(image_data_size);
		BASISU_NOTE_UNUSED(pImage_data);
		BASISU_NOTE_UNUSED(num_blocks_x);
		BASISU_NOTE_UNUSED(num_blocks_y);
		BASISU_NOTE_UNUSED(pDst_blocks);

		return false;
#endif
	}

	bool basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_image(
		transcoder_texture_format target_format,
		void* pOutput_blocks, uint32_t output_blocks_buf_size_in_blocks_or_pixels,
		const uint8_t* pCompressed_data, uint32_t compressed_data_length,
		uint32_t num_blocks_x, uint32_t num_blocks_y, uint32_t orig_width, uint32_t orig_height, uint32_t level_index,
		uint64_t slice_offset, uint32_t slice_length,
		uint32_t decode_flags,
		bool has_alpha,
		bool is_video,
		uint32_t output_row_pitch_in_blocks_or_pixels,
		basisu_transcoder_state* pState,
		uint32_t output_rows_in_pixels,
		int channel0, int channel1)
	{
		BASISU_NOTE_UNUSED(is_video);
		BASISU_NOTE_UNUSED(level_index);
		BASISU_NOTE_UNUSED(decode_flags);

		if (((uint64_t)slice_offset + slice_length) > (uint64_t)compressed_data_length)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_image: source data buffer too small\n");
			return false;
		}

		const uint32_t bytes_per_block_or_pixel = basis_get_bytes_per_block_or_pixel(target_format);
		//const uint32_t total_slice_blocks = num_blocks_x * num_blocks_y;

		if (!basis_validate_output_buffer_size(basis_tex_format::cASTC_HDR_6x6, target_format, output_blocks_buf_size_in_blocks_or_pixels, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, output_rows_in_pixels))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_image: output buffer size too small\n");
			return false;
		}

		bool status = false;

		switch (target_format)
		{
		case transcoder_texture_format::cTFASTC_HDR_6x6_RGBA:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cASTC_HDR_6x6,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);

			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_image: transcode_slice() to ASTC_HDR failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFBC6H:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC6H,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_image: transcode_slice() to BC6H failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGB_HALF:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGB_HALF,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_image: transcode_slice() to RGB_HALF failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGBA_HALF:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGBA_HALF,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_image: transcode_slice() to RGBA_HALF failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGB_9E5:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGB_9E5,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_image: transcode_slice() to RGBA_HALF failed\n");
			}
			break;
		}
		default:
		{
			assert(0);
			BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_image: Invalid format\n");
			break;
		}
		}

		return status;
	}

	//------------------------------------------------------------------------------------------------
	// ASTC 6x6 HDR intermediate

	basisu_lowlevel_astc_hdr_6x6_intermediate_transcoder::basisu_lowlevel_astc_hdr_6x6_intermediate_transcoder()
	{
	}

	// num_blocks_x/num_blocks_y are source 6x6 blocks
	bool basisu_lowlevel_astc_hdr_6x6_intermediate_transcoder::transcode_slice(
		void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y, const uint8_t* pImage_data, uint32_t image_data_size, block_format fmt,
		uint32_t output_block_or_pixel_stride_in_bytes, bool bc1_allow_threecolor_blocks, bool has_alpha,
		const uint32_t orig_width, const uint32_t orig_height, uint32_t output_row_pitch_in_blocks_or_pixels,
		basisu_transcoder_state* pState, uint32_t output_rows_in_pixels, int channel0, int channel1, uint32_t decode_flags)
	{
		BASISU_NOTE_UNUSED(pState);
		BASISU_NOTE_UNUSED(bc1_allow_threecolor_blocks);
		BASISU_NOTE_UNUSED(has_alpha);
		BASISU_NOTE_UNUSED(channel0);
		BASISU_NOTE_UNUSED(channel1);
		BASISU_NOTE_UNUSED(decode_flags);
		BASISU_NOTE_UNUSED(orig_width);
		BASISU_NOTE_UNUSED(orig_height);

		assert(g_transcoder_initialized);
		if (!g_transcoder_initialized)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_intermediate_transcoder::transcode_slice: Transcoder not globally initialized.\n");
			return false;
		}

#if BASISD_SUPPORT_UASTC_HDR

		// TODO: Optimize this

		basisu::vector2D<astc_helpers::astc_block> decoded_blocks;
		uint32_t dec_width = 0, dec_height = 0;
		bool dec_status = astc_6x6_hdr::decode_6x6_hdr(pImage_data, image_data_size, decoded_blocks, dec_width, dec_height);
		if (!dec_status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_intermediate_transcoder::transcode_slice: decode_6x6_hdr() failed.\n");
			return false;
		}

		if ((dec_width != orig_width) || (dec_height != orig_height) ||
			(decoded_blocks.get_width() != num_blocks_x) || (decoded_blocks.get_height() != num_blocks_y))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_intermediate_transcoder::transcode_slice: unexpected decoded width/height\n");
			return false;
		}

		//const uint32_t total_src_blocks = num_blocks_x * num_blocks_y;

		const uint32_t output_block_width = get_block_width(fmt);
		//const uint32_t output_block_height = get_block_height(fmt);

		if (!output_row_pitch_in_blocks_or_pixels)
		{
			if (basis_block_format_is_uncompressed(fmt))
				output_row_pitch_in_blocks_or_pixels = orig_width;
			else
				output_row_pitch_in_blocks_or_pixels = (orig_width + output_block_width - 1) / output_block_width;
		}

		if (basis_block_format_is_uncompressed(fmt))
		{
			if (!output_rows_in_pixels)
				output_rows_in_pixels = orig_height;
		}

		const astc_blk* pSource_block = (const astc_blk *)decoded_blocks.get_ptr();

		bool status = false;

		half_float unpacked_blocks[12][12][3]; // [y][x][c]

		assert(((orig_width + 5) / 6) == num_blocks_x);
		assert(((orig_height + 5) / 6) == num_blocks_y);

		if (fmt == block_format::cBC6H)
		{
			const uint32_t num_dst_blocks_x = (orig_width + 3) / 4;
			const uint32_t num_dst_blocks_y = (orig_height + 3) / 4;

			if (!output_row_pitch_in_blocks_or_pixels)
			{
				output_row_pitch_in_blocks_or_pixels = num_dst_blocks_x;
			}
			else if (output_row_pitch_in_blocks_or_pixels < num_dst_blocks_x)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_intermediate_transcoder::transcode_slice: output_row_pitch_in_blocks_or_pixels is too low\n");
				return false;
			}

			if (output_block_or_pixel_stride_in_bytes != sizeof(bc6h_block))
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_intermediate_transcoder::transcode_slice: invalid output_block_or_pixel_stride_in_bytes\n");
				return false;
			}

			fast_bc6h_params bc6h_enc_params;
			const bool hq_flag = (decode_flags & cDecodeFlagsHighQuality) != 0;
			bc6h_enc_params.m_max_2subset_pats_to_try = hq_flag ? 1 : 0;
									
			for (uint32_t src_block_y = 0; src_block_y < num_blocks_y; src_block_y += 2)
			{
				const uint32_t num_inner_blocks_y = basisu::minimum<uint32_t>(2, num_blocks_y - src_block_y);

				for (uint32_t src_block_x = 0; src_block_x < num_blocks_x; src_block_x += 2)
				{
					const uint32_t num_inner_blocks_x = basisu::minimum<uint32_t>(2, num_blocks_x - src_block_x);

					for (uint32_t iy = 0; iy < num_inner_blocks_y; iy++)
					{
						for (uint32_t ix = 0; ix < num_inner_blocks_x; ix++)
						{
							const astc_blk* pS = pSource_block + (src_block_y + iy) * num_blocks_x + (src_block_x + ix);

							half_float blk_texels[6][6][4];

							astc_helpers::log_astc_block log_blk;
							status = astc_helpers::unpack_block(pS, log_blk, 6, 6);
							if (!status)
							{
								BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_intermediate_transcoder::transcode_slice: Transcoder failed to unpack a ASTC HDR block - this is a bug, or the data was corrupted\n");
								return false;
							}

							status = astc_helpers::decode_block(log_blk, blk_texels, 6, 6, astc_helpers::cDecodeModeHDR16);
							if (!status)
							{
								BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_intermediate_transcoder::transcode_slice: Transcoder failed to unpack a ASTC HDR block - this is a bug, or the data was corrupted\n");
								return false;
							}

							for (uint32_t y = 0; y < 6; y++)
							{
								for (uint32_t x = 0; x < 6; x++)
								{
									unpacked_blocks[iy * 6 + y][ix * 6 + x][0] = blk_texels[y][x][0];
									unpacked_blocks[iy * 6 + y][ix * 6 + x][1] = blk_texels[y][x][1];
									unpacked_blocks[iy * 6 + y][ix * 6 + x][2] = blk_texels[y][x][2];
								} // x
							} // y

						} // ix

					} // iy

					const uint32_t dst_x = src_block_x * 6;
					assert((dst_x & 3) == 0);
					const uint32_t dst_block_x = dst_x >> 2;

					const uint32_t dst_y = src_block_y * 6;
					assert((dst_y & 3) == 0);
					const uint32_t dst_block_y = dst_y >> 2;

					const uint32_t num_inner_dst_blocks_x = basisu::minimum<uint32_t>(3, num_dst_blocks_x - dst_block_x);
					const uint32_t num_inner_dst_blocks_y = basisu::minimum<uint32_t>(3, num_dst_blocks_y - dst_block_y);

					for (uint32_t dy = 0; dy < num_inner_dst_blocks_y; dy++)
					{
						for (uint32_t dx = 0; dx < num_inner_dst_blocks_x; dx++)
						{
							bc6h_block* pDst_block = (bc6h_block*)pDst_blocks + (dst_block_x + dx) + (dst_block_y + dy) * output_row_pitch_in_blocks_or_pixels;

							half_float src_pixels[4][4][3]; // [y][x][c]

							for (uint32_t y = 0; y < 4; y++)
							{
								const uint32_t src_pixel_y = basisu::minimum<uint32_t>(dy * 4 + y, num_inner_blocks_y * 6 - 1);

								for (uint32_t x = 0; x < 4; x++)
								{
									const uint32_t src_pixel_x = basisu::minimum<uint32_t>(dx * 4 + x, num_inner_blocks_x * 6 - 1);

									assert((src_pixel_y < 12) && (src_pixel_x < 12));

									src_pixels[y][x][0] = unpacked_blocks[src_pixel_y][src_pixel_x][0];
									src_pixels[y][x][1] = unpacked_blocks[src_pixel_y][src_pixel_x][1];
									src_pixels[y][x][2] = unpacked_blocks[src_pixel_y][src_pixel_x][2];

								} // x
							} // y
														
							astc_6x6_hdr::fast_encode_bc6h(&src_pixels[0][0][0], pDst_block, bc6h_enc_params);

						} // dx
					} // dy

				} // block_x

			} // block_y

			status = true;
		}
		else
		{
			for (uint32_t block_y = 0; block_y < num_blocks_y; ++block_y)
			{
				void* pDst_block = (uint8_t*)pDst_blocks + block_y * output_row_pitch_in_blocks_or_pixels * output_block_or_pixel_stride_in_bytes;

				for (uint32_t block_x = 0; block_x < num_blocks_x; ++block_x, ++pSource_block, pDst_block = (uint8_t*)pDst_block + output_block_or_pixel_stride_in_bytes)
				{
					switch (fmt)
					{
					case block_format::cASTC_HDR_6x6:
					{
						// Nothing to do, ASTC HDR 6x6 is just ASTC.
						// TODO: Optimize this copy
						memcpy(pDst_block, pSource_block, sizeof(astc_helpers::astc_block));
						status = true;
						break;
					}
					case block_format::cRGB_9E5:
					{
						astc_helpers::log_astc_block log_blk;
						status = astc_helpers::unpack_block(pSource_block, log_blk, 6, 6);
						if (status)
						{
							uint32_t* pDst_pixels = reinterpret_cast<uint32_t*>(
								static_cast<uint8_t*>(pDst_blocks) + (block_x * 6 + block_y * 6 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint32_t)
								);

							uint32_t blk_texels[6][6];

							status = astc_helpers::decode_block(log_blk, blk_texels, 6, 6, astc_helpers::cDecodeModeRGB9E5);

							if (status)
							{
								const uint32_t max_x = basisu::minimum<int>(6, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 6);
								const uint32_t max_y = basisu::minimum<int>(6, (int)output_rows_in_pixels - (int)block_y * 6);

								for (uint32_t y = 0; y < max_y; y++)
								{
									memcpy(pDst_pixels, &blk_texels[y][0], sizeof(uint32_t) * max_x);

									pDst_pixels += output_row_pitch_in_blocks_or_pixels;
								} // y
							}
						}

						break;
					}
					case block_format::cRGBA_HALF:
					{
						astc_helpers::log_astc_block log_blk;
						status = astc_helpers::unpack_block(pSource_block, log_blk, 6, 6);
						if (status)
						{
							half_float* pDst_pixels = reinterpret_cast<half_float*>(
								static_cast<uint8_t*>(pDst_blocks) + (block_x * 6 + block_y * 6 * output_row_pitch_in_blocks_or_pixels) * sizeof(half_float) * 4
								);

							half_float blk_texels[6][6][4];
							status = astc_helpers::decode_block(log_blk, blk_texels, 6, 6, astc_helpers::cDecodeModeHDR16);

							if (status)
							{
								const uint32_t max_x = basisu::minimum<int>(6, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 6);
								const uint32_t max_y = basisu::minimum<int>(6, (int)output_rows_in_pixels - (int)block_y * 6);

								for (uint32_t y = 0; y < max_y; y++)
								{
									for (uint32_t x = 0; x < max_x; x++)
									{
										pDst_pixels[0 + 4 * x] = blk_texels[y][x][0];
										pDst_pixels[1 + 4 * x] = blk_texels[y][x][1];
										pDst_pixels[2 + 4 * x] = blk_texels[y][x][2];
										pDst_pixels[3 + 4 * x] = blk_texels[y][x][3];
									} // x

									pDst_pixels += output_row_pitch_in_blocks_or_pixels * 4;
								} // y
							}
						}

						break;
					}
					case block_format::cRGB_HALF:
					{
						astc_helpers::log_astc_block log_blk;
						status = astc_helpers::unpack_block(pSource_block, log_blk, 6, 6);
						if (status)
						{
							half_float* pDst_pixels =
								reinterpret_cast<half_float*>(static_cast<uint8_t*>(pDst_blocks) + (block_x * 6 + block_y * 6 * output_row_pitch_in_blocks_or_pixels) * sizeof(half_float) * 3);

							half_float blk_texels[6][6][4];
							status = astc_helpers::decode_block(log_blk, blk_texels, 6, 6, astc_helpers::cDecodeModeHDR16);
							if (status)
							{
								const uint32_t max_x = basisu::minimum<int>(6, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 6);
								const uint32_t max_y = basisu::minimum<int>(6, (int)output_rows_in_pixels - (int)block_y * 6);

								for (uint32_t y = 0; y < max_y; y++)
								{
									for (uint32_t x = 0; x < max_x; x++)
									{
										pDst_pixels[0 + 3 * x] = blk_texels[y][x][0];
										pDst_pixels[1 + 3 * x] = blk_texels[y][x][1];
										pDst_pixels[2 + 3 * x] = blk_texels[y][x][2];
									} // x

									pDst_pixels += output_row_pitch_in_blocks_or_pixels * 3;
								} // y
							}
						}

						break;
					}
					default:
						assert(0);
						break;

					}

					if (!status)
					{
						BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_intermediate_transcoder::transcode_slice: Transcoder failed to unpack a ASTC HDR block - this is a bug, or the data was corrupted\n");
						return false;
					}

				} // block_x

			} // block_y
		}

		return true;
#else
		BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_intermediate_transcoder::transcode_slice: ASTC HDR is unsupported\n");

		BASISU_NOTE_UNUSED(decode_flags);
		BASISU_NOTE_UNUSED(channel0);
		BASISU_NOTE_UNUSED(channel1);
		BASISU_NOTE_UNUSED(output_rows_in_pixels);
		BASISU_NOTE_UNUSED(output_row_pitch_in_blocks_or_pixels);
		BASISU_NOTE_UNUSED(output_block_or_pixel_stride_in_bytes);
		BASISU_NOTE_UNUSED(fmt);
		BASISU_NOTE_UNUSED(image_data_size);
		BASISU_NOTE_UNUSED(pImage_data);
		BASISU_NOTE_UNUSED(num_blocks_x);
		BASISU_NOTE_UNUSED(num_blocks_y);
		BASISU_NOTE_UNUSED(pDst_blocks);

		return false;
#endif
	}

	bool basisu_lowlevel_astc_hdr_6x6_intermediate_transcoder::transcode_image(
		transcoder_texture_format target_format,
		void* pOutput_blocks, uint32_t output_blocks_buf_size_in_blocks_or_pixels,
		const uint8_t* pCompressed_data, uint32_t compressed_data_length,
		uint32_t num_blocks_x, uint32_t num_blocks_y, uint32_t orig_width, uint32_t orig_height, uint32_t level_index,
		uint64_t slice_offset, uint32_t slice_length,
		uint32_t decode_flags,
		bool has_alpha,
		bool is_video,
		uint32_t output_row_pitch_in_blocks_or_pixels,
		basisu_transcoder_state* pState,
		uint32_t output_rows_in_pixels,
		int channel0, int channel1)
	{
		BASISU_NOTE_UNUSED(is_video);
		BASISU_NOTE_UNUSED(level_index);
		BASISU_NOTE_UNUSED(decode_flags);

		if (((uint64_t)slice_offset + slice_length) > (uint64_t)compressed_data_length)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_intermediate_transcoder::transcode_image: source data buffer too small\n");
			return false;
		}

		const uint32_t bytes_per_block_or_pixel = basis_get_bytes_per_block_or_pixel(target_format);
		//const uint32_t total_slice_blocks = num_blocks_x * num_blocks_y;

		if (!basis_validate_output_buffer_size(basis_tex_format::cASTC_HDR_6x6, target_format, output_blocks_buf_size_in_blocks_or_pixels, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, output_rows_in_pixels))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_intermediate_transcoder::transcode_image: output buffer size too small\n");
			return false;
		}

		bool status = false;

		switch (target_format)
		{
		case transcoder_texture_format::cTFASTC_HDR_6x6_RGBA:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cASTC_HDR_6x6,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);

			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_intermediate_transcoder::transcode_image: transcode_slice() to ASTC_HDR failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFBC6H:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC6H,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_intermediate_transcoder::transcode_image: transcode_slice() to BC6H failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGB_HALF:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGB_HALF,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_intermediate_transcoder::transcode_image: transcode_slice() to RGB_HALF failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGBA_HALF:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGBA_HALF,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_intermediate_transcoder::transcode_image: transcode_slice() to RGBA_HALF failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGB_9E5:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGB_9E5,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1 , decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_intermediate_transcoder::transcode_image: transcode_slice() to RGBA_HALF failed\n");
			}
			break;
		}
		default:
		{
			assert(0);
			BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_intermediate_transcoder::transcode_image: Invalid format\n");
			break;
		}
		}

		return status;
	}

	//------------------------------------------------------------------------------------------------
	
	basisu_transcoder::basisu_transcoder() :
		m_ready_to_transcode(false)
	{
	}

	bool basisu_transcoder::validate_file_checksums(const void* pData, uint32_t data_size, bool full_validation) const
	{
		if (!validate_header(pData, data_size))
			return false;

		const basis_file_header* pHeader = reinterpret_cast<const basis_file_header*>(pData);

#if !BASISU_NO_HEADER_OR_DATA_CRC16_CHECKS
		if (crc16(&pHeader->m_data_size, sizeof(basis_file_header) - BASISU_OFFSETOF(basis_file_header, m_data_size), 0) != pHeader->m_header_crc16)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: header CRC check failed\n");
			return false;
		}

		if (full_validation)
		{
			if (crc16(reinterpret_cast<const uint8_t*>(pData) + sizeof(basis_file_header), pHeader->m_data_size, 0) != pHeader->m_data_crc16)
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: data CRC check failed\n");
				return false;
			}
		}
#endif		

		return true;
	}

	bool basisu_transcoder::validate_header_quick(const void* pData, uint32_t data_size) const
	{
		if (data_size <= sizeof(basis_file_header))
			return false;

		const basis_file_header* pHeader = reinterpret_cast<const basis_file_header*>(pData);

		if ((pHeader->m_sig != basis_file_header::cBASISSigValue) || (pHeader->m_ver != BASISD_SUPPORTED_BASIS_VERSION) || (pHeader->m_header_size != sizeof(basis_file_header)))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: header has an invalid signature, or file version is unsupported\n");
			return false;
		}

		uint32_t expected_file_size = sizeof(basis_file_header) + pHeader->m_data_size;
		if (data_size < expected_file_size)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: source buffer is too small\n");
			return false;
		}

		if ((!pHeader->m_total_slices) || (!pHeader->m_total_images))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::validate_header_quick: header is invalid\n");
			return false;
		}

		if ((pHeader->m_slice_desc_file_ofs >= data_size) ||
			((data_size - pHeader->m_slice_desc_file_ofs) < (sizeof(basis_slice_desc) * pHeader->m_total_slices))
			)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::validate_header_quick: passed in buffer is too small or data is corrupted\n");
			return false;
		}

		return true;
	}

	bool basisu_transcoder::validate_header(const void* pData, uint32_t data_size) const
	{
		if (data_size <= sizeof(basis_file_header))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: input source buffer is too small\n");
			return false;
		}

		const basis_file_header* pHeader = reinterpret_cast<const basis_file_header*>(pData);

		if ((pHeader->m_sig != basis_file_header::cBASISSigValue) || (pHeader->m_ver != BASISD_SUPPORTED_BASIS_VERSION) || (pHeader->m_header_size != sizeof(basis_file_header)))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: header has an invalid signature, or file version is unsupported\n");
			return false;
		}

		uint32_t expected_file_size = sizeof(basis_file_header) + pHeader->m_data_size;
		if (data_size < expected_file_size)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: input source buffer is too small, or header is corrupted\n");
			return false;
		}

		if ((!pHeader->m_total_images) || (!pHeader->m_total_slices))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: invalid basis file (total images or slices are 0)\n");
			return false;
		}

		if (pHeader->m_total_images > pHeader->m_total_slices)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: invalid basis file (too many images)\n");
			return false;
		}

		if (pHeader->m_tex_format == (int)basis_tex_format::cETC1S)
		{
			if (pHeader->m_flags & cBASISHeaderFlagHasAlphaSlices)
			{
				if (pHeader->m_total_slices & 1)
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: invalid alpha .basis file\n");
					return false;
				}
			}
		
			// This flag dates back to pre-Basis Universal, when .basis supported full ETC1 too.
			if ((pHeader->m_flags & cBASISHeaderFlagETC1S) == 0)
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: Invalid .basis file (ETC1S check)\n");
				return false;
			}
		}
		else
		{
			if ((pHeader->m_flags & cBASISHeaderFlagETC1S) != 0)
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: Invalid .basis file (ETC1S check)\n");
				return false;
			}
		}
		
		if ((pHeader->m_slice_desc_file_ofs >= data_size) ||
			((data_size - pHeader->m_slice_desc_file_ofs) < (sizeof(basis_slice_desc) * pHeader->m_total_slices))
			)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::validate_header_quick: passed in buffer is too small or data is corrupted\n");
			return false;
		}

		return true;
	}

	basis_texture_type basisu_transcoder::get_texture_type(const void* pData, uint32_t data_size) const
	{
		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_texture_type: header validation failed\n");
			return cBASISTexType2DArray;
		}

		const basis_file_header* pHeader = static_cast<const basis_file_header*>(pData);

		basis_texture_type btt = static_cast<basis_texture_type>(static_cast<uint8_t>(pHeader->m_tex_type));

		if (btt >= cBASISTexTypeTotal)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::validate_header_quick: header's texture type field is invalid\n");
			return cBASISTexType2DArray;
		}

		return btt;
	}

	bool basisu_transcoder::get_userdata(const void* pData, uint32_t data_size, uint32_t& userdata0, uint32_t& userdata1) const
	{
		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_userdata: header validation failed\n");
			return false;
		}

		const basis_file_header* pHeader = static_cast<const basis_file_header*>(pData);

		userdata0 = pHeader->m_userdata0;
		userdata1 = pHeader->m_userdata1;
		return true;
	}

	uint32_t basisu_transcoder::get_total_images(const void* pData, uint32_t data_size) const
	{
		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: header validation failed\n");
			return 0;
		}

		const basis_file_header* pHeader = static_cast<const basis_file_header*>(pData);

		return pHeader->m_total_images;
	}

	basis_tex_format basisu_transcoder::get_basis_tex_format(const void* pData, uint32_t data_size) const
	{
		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_basis_tex_format: header validation failed\n");
			return basis_tex_format::cETC1S;
		}

		const basis_file_header* pHeader = static_cast<const basis_file_header*>(pData);

		return (basis_tex_format)(uint32_t)pHeader->m_tex_format;
	}

	bool basisu_transcoder::get_image_info(const void* pData, uint32_t data_size, basisu_image_info& image_info, uint32_t image_index) const
	{
		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_info: header validation failed\n");
			return false;
		}

		int slice_index = find_first_slice_index(pData, data_size, image_index, 0);
		if (slice_index < 0)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_info: invalid slice index\n");
			return false;
		}

		const basis_file_header* pHeader = static_cast<const basis_file_header*>(pData);

		if (image_index >= pHeader->m_total_images)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_info: invalid image_index\n");
			return false;
		}

		const basis_slice_desc* pSlice_descs = reinterpret_cast<const basis_slice_desc*>(static_cast<const uint8_t*>(pData) + pHeader->m_slice_desc_file_ofs);

		uint32_t total_levels = 1;
		for (uint32_t i = slice_index + 1; i < pHeader->m_total_slices; i++)
			if (pSlice_descs[i].m_image_index == image_index)
				total_levels = basisu::maximum<uint32_t>(total_levels, pSlice_descs[i].m_level_index + 1);
			else
				break;

		if (total_levels > 16)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_info: invalid image_index\n");
			return false;
		}

		const basis_slice_desc& slice_desc = pSlice_descs[slice_index];

		image_info.m_image_index = image_index;
		image_info.m_total_levels = total_levels;
		
		image_info.m_alpha_flag = false;

		// For ETC1S, if anything has alpha all images have alpha. For UASTC, we only report alpha when the image actually has alpha.
		if (pHeader->m_tex_format == (int)basis_tex_format::cETC1S)
			image_info.m_alpha_flag = (pHeader->m_flags & cBASISHeaderFlagHasAlphaSlices) != 0; 
		else
			image_info.m_alpha_flag = (slice_desc.m_flags & cSliceDescFlagsHasAlpha) != 0;

		image_info.m_iframe_flag = (slice_desc.m_flags & cSliceDescFlagsFrameIsIFrame) != 0;
				
		const uint32_t block_width = basis_tex_format_get_block_width((basis_tex_format)((uint32_t)pHeader->m_tex_format));
		const uint32_t block_height = basis_tex_format_get_block_height((basis_tex_format)((uint32_t)pHeader->m_tex_format));
				
		image_info.m_width = slice_desc.m_num_blocks_x * block_width;
		image_info.m_height = slice_desc.m_num_blocks_y * block_height;
		image_info.m_orig_width = slice_desc.m_orig_width;
		image_info.m_orig_height = slice_desc.m_orig_height;
		image_info.m_num_blocks_x = slice_desc.m_num_blocks_x;
		image_info.m_num_blocks_y = slice_desc.m_num_blocks_y;
		image_info.m_block_width = block_width;
		image_info.m_block_height = block_height;
		image_info.m_total_blocks = image_info.m_num_blocks_x * image_info.m_num_blocks_y;
		image_info.m_first_slice_index = slice_index;

		return true;
	}

	uint32_t basisu_transcoder::get_total_image_levels(const void* pData, uint32_t data_size, uint32_t image_index) const
	{
		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_image_levels: header validation failed\n");
			return false;
		}

		int slice_index = find_first_slice_index(pData, data_size, image_index, 0);
		if (slice_index < 0)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_image_levels: failed finding slice\n");
			return false;
		}

		const basis_file_header* pHeader = static_cast<const basis_file_header*>(pData);

		if (image_index >= pHeader->m_total_images)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_image_levels: invalid image_index\n");
			return false;
		}

		const basis_slice_desc* pSlice_descs = reinterpret_cast<const basis_slice_desc*>(static_cast<const uint8_t*>(pData) + pHeader->m_slice_desc_file_ofs);

		uint32_t total_levels = 1;
		for (uint32_t i = slice_index + 1; i < pHeader->m_total_slices; i++)
			if (pSlice_descs[i].m_image_index == image_index)
				total_levels = basisu::maximum<uint32_t>(total_levels, pSlice_descs[i].m_level_index + 1);
			else
				break;

		const uint32_t cMaxSupportedLevels = 16;
		if (total_levels > cMaxSupportedLevels)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_image_levels: invalid image levels!\n");
			return false;
		}

		return total_levels;
	}

	bool basisu_transcoder::get_image_level_desc(const void* pData, uint32_t data_size, uint32_t image_index, uint32_t level_index, uint32_t& orig_width, uint32_t& orig_height, uint32_t& total_blocks) const
	{
		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_level_desc: header validation failed\n");
			return false;
		}

		int slice_index = find_first_slice_index(pData, data_size, image_index, level_index);
		if (slice_index < 0)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_level_desc: failed finding slice\n");
			return false;
		}

		const basis_file_header* pHeader = static_cast<const basis_file_header*>(pData);

		if (image_index >= pHeader->m_total_images)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_level_desc: invalid image_index\n");
			return false;
		}

		const basis_slice_desc* pSlice_descs = reinterpret_cast<const basis_slice_desc*>(static_cast<const uint8_t*>(pData) + pHeader->m_slice_desc_file_ofs);

		const basis_slice_desc& slice_desc = pSlice_descs[slice_index];

		orig_width = slice_desc.m_orig_width;
		orig_height = slice_desc.m_orig_height;
		total_blocks = slice_desc.m_num_blocks_x * slice_desc.m_num_blocks_y;

		return true;
	}

	bool basisu_transcoder::get_image_level_info(const void* pData, uint32_t data_size, basisu_image_level_info& image_info, uint32_t image_index, uint32_t level_index) const
	{
		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_level_info: validate_file_checksums failed\n");
			return false;
		}

		int slice_index = find_first_slice_index(pData, data_size, image_index, level_index);
		if (slice_index < 0)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_level_info: failed finding slice\n");
			return false;
		}

		const basis_file_header* pHeader = static_cast<const basis_file_header*>(pData);

		if (image_index >= pHeader->m_total_images)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_level_info: invalid image_index\n");
			return false;
		}

		const basis_slice_desc* pSlice_descs = reinterpret_cast<const basis_slice_desc*>(static_cast<const uint8_t*>(pData) + pHeader->m_slice_desc_file_ofs);

		const basis_slice_desc& slice_desc = pSlice_descs[slice_index];

		image_info.m_image_index = image_index;
		image_info.m_level_index = level_index;
		
		// For ETC1S, if anything has alpha all images have alpha. For UASTC, we only report alpha when the image actually has alpha.
		if (pHeader->m_tex_format == (int)basis_tex_format::cETC1S)
			image_info.m_alpha_flag = (pHeader->m_flags & cBASISHeaderFlagHasAlphaSlices) != 0;
		else
			image_info.m_alpha_flag = (slice_desc.m_flags & cSliceDescFlagsHasAlpha) != 0;
		
		const uint32_t block_width = basis_tex_format_get_block_width((basis_tex_format)((uint32_t)pHeader->m_tex_format));
		const uint32_t block_height = basis_tex_format_get_block_height((basis_tex_format)((uint32_t)pHeader->m_tex_format));

		image_info.m_iframe_flag = (slice_desc.m_flags & cSliceDescFlagsFrameIsIFrame) != 0;
		image_info.m_width = slice_desc.m_num_blocks_x * block_width;
		image_info.m_height = slice_desc.m_num_blocks_y * block_height;
		image_info.m_orig_width = slice_desc.m_orig_width;
		image_info.m_orig_height = slice_desc.m_orig_height;
		image_info.m_block_width = block_width;
		image_info.m_block_height = block_height;
		image_info.m_num_blocks_x = slice_desc.m_num_blocks_x;
		image_info.m_num_blocks_y = slice_desc.m_num_blocks_y;
		image_info.m_total_blocks = image_info.m_num_blocks_x * image_info.m_num_blocks_y;
		image_info.m_first_slice_index = slice_index;

		image_info.m_rgb_file_ofs = slice_desc.m_file_ofs;
		image_info.m_rgb_file_len = slice_desc.m_file_size;
		image_info.m_alpha_file_ofs = 0;
		image_info.m_alpha_file_len = 0;

		if (pHeader->m_tex_format == (int)basis_tex_format::cETC1S)
		{
			if (pHeader->m_flags & cBASISHeaderFlagHasAlphaSlices)
			{
				assert((slice_index + 1) < (int)pHeader->m_total_slices);
				image_info.m_alpha_file_ofs = pSlice_descs[slice_index + 1].m_file_ofs;
				image_info.m_alpha_file_len = pSlice_descs[slice_index + 1].m_file_size;
			}
		}

		return true;
	}

	bool basisu_transcoder::get_file_info(const void* pData, uint32_t data_size, basisu_file_info& file_info) const
	{
		if (!validate_file_checksums(pData, data_size, false))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_file_info: validate_file_checksums failed\n");
			return false;
		}

		const basis_file_header* pHeader = static_cast<const basis_file_header*>(pData);
		const basis_slice_desc* pSlice_descs = reinterpret_cast<const basis_slice_desc*>(static_cast<const uint8_t*>(pData) + pHeader->m_slice_desc_file_ofs);

		file_info.m_version = pHeader->m_ver;

		file_info.m_total_header_size = sizeof(basis_file_header) + pHeader->m_total_slices * sizeof(basis_slice_desc);

		file_info.m_total_selectors = pHeader->m_total_selectors;
		file_info.m_selector_codebook_ofs = pHeader->m_selector_cb_file_ofs;
		file_info.m_selector_codebook_size = pHeader->m_selector_cb_file_size;

		file_info.m_total_endpoints = pHeader->m_total_endpoints;
		file_info.m_endpoint_codebook_ofs = pHeader->m_endpoint_cb_file_ofs;
		file_info.m_endpoint_codebook_size = pHeader->m_endpoint_cb_file_size;

		file_info.m_tables_ofs = pHeader->m_tables_file_ofs;
		file_info.m_tables_size = pHeader->m_tables_file_size;

		file_info.m_tex_format = static_cast<basis_tex_format>(static_cast<int>(pHeader->m_tex_format));

		file_info.m_etc1s = (pHeader->m_tex_format == (int)basis_tex_format::cETC1S);
		
		file_info.m_y_flipped = (pHeader->m_flags & cBASISHeaderFlagYFlipped) != 0;
		file_info.m_has_alpha_slices = (pHeader->m_flags & cBASISHeaderFlagHasAlphaSlices) != 0;

		const uint32_t total_slices = pHeader->m_total_slices;

		file_info.m_slice_info.resize(total_slices);

		file_info.m_slices_size = 0;

		file_info.m_tex_type = static_cast<basis_texture_type>(static_cast<uint8_t>(pHeader->m_tex_type));

		if (file_info.m_tex_type > cBASISTexTypeTotal)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_file_info: invalid texture type, file is corrupted\n");
			return false;
		}

		file_info.m_us_per_frame = pHeader->m_us_per_frame;
		file_info.m_userdata0 = pHeader->m_userdata0;
		file_info.m_userdata1 = pHeader->m_userdata1;

		file_info.m_image_mipmap_levels.resize(0);
		file_info.m_image_mipmap_levels.resize(pHeader->m_total_images);

		file_info.m_total_images = pHeader->m_total_images;

		const uint32_t block_width = basis_tex_format_get_block_width((basis_tex_format)((uint32_t)pHeader->m_tex_format));
		const uint32_t block_height = basis_tex_format_get_block_height((basis_tex_format)((uint32_t)pHeader->m_tex_format));
		file_info.m_block_width = block_width;
		file_info.m_block_height = block_height;

		for (uint32_t i = 0; i < total_slices; i++)
		{
			file_info.m_slices_size += pSlice_descs[i].m_file_size;

			basisu_slice_info& slice_info = file_info.m_slice_info[i];

			slice_info.m_orig_width = pSlice_descs[i].m_orig_width;
			slice_info.m_orig_height = pSlice_descs[i].m_orig_height;
			slice_info.m_width = pSlice_descs[i].m_num_blocks_x * block_width;
			slice_info.m_height = pSlice_descs[i].m_num_blocks_y * block_height;
			slice_info.m_num_blocks_x = pSlice_descs[i].m_num_blocks_x;
			slice_info.m_num_blocks_y = pSlice_descs[i].m_num_blocks_y;
			slice_info.m_block_width = block_width;
			slice_info.m_block_height = block_height;
			slice_info.m_total_blocks = slice_info.m_num_blocks_x * slice_info.m_num_blocks_y;
			slice_info.m_compressed_size = pSlice_descs[i].m_file_size;
			slice_info.m_slice_index = i;
			slice_info.m_image_index = pSlice_descs[i].m_image_index;
			slice_info.m_level_index = pSlice_descs[i].m_level_index;
			slice_info.m_unpacked_slice_crc16 = pSlice_descs[i].m_slice_data_crc16;
			slice_info.m_alpha_flag = (pSlice_descs[i].m_flags & cSliceDescFlagsHasAlpha) != 0;
			slice_info.m_iframe_flag = (pSlice_descs[i].m_flags & cSliceDescFlagsFrameIsIFrame) != 0;

			if (pSlice_descs[i].m_image_index >= pHeader->m_total_images)
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::get_file_info: slice desc's image index is invalid\n");
				return false;
			}

			file_info.m_image_mipmap_levels[pSlice_descs[i].m_image_index] = basisu::maximum<uint32_t>(file_info.m_image_mipmap_levels[pSlice_descs[i].m_image_index], pSlice_descs[i].m_level_index + 1);

			if (file_info.m_image_mipmap_levels[pSlice_descs[i].m_image_index] > 16)
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::get_file_info: slice mipmap level is invalid\n");
				return false;
			}
		}

		return true;
	}
		
	bool basisu_transcoder::start_transcoding(const void* pData, uint32_t data_size)
	{
		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: header validation failed\n");
			return false;
		}

		const basis_file_header* pHeader = reinterpret_cast<const basis_file_header*>(pData);
		const uint8_t* pDataU8 = static_cast<const uint8_t*>(pData);

		if (pHeader->m_tex_format == (int)basis_tex_format::cETC1S)
		{
			if (m_lowlevel_etc1s_decoder.m_local_endpoints.size())
			{
				m_lowlevel_etc1s_decoder.clear();
			}

			if (pHeader->m_flags & cBASISHeaderFlagUsesGlobalCodebook)
			{
				if (!m_lowlevel_etc1s_decoder.get_global_codebooks())
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: File uses global codebooks, but set_global_codebooks() has not been called\n");
					return false;
				}
				if (!m_lowlevel_etc1s_decoder.get_global_codebooks()->get_endpoints().size())
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: Global codebooks must be unpacked first by calling start_transcoding()\n");
					return false;
				}
				if ((m_lowlevel_etc1s_decoder.get_global_codebooks()->get_endpoints().size() != pHeader->m_total_endpoints) ||
					 (m_lowlevel_etc1s_decoder.get_global_codebooks()->get_selectors().size() != pHeader->m_total_selectors))
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: Global codebook size mismatch (wrong codebooks for file).\n");
					return false;
				}
				if (!pHeader->m_tables_file_size)
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: file is corrupted (2)\n");
					return false;
				}
				if (pHeader->m_tables_file_ofs > data_size)
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: file is corrupted or passed in buffer too small (4)\n");
					return false;
				}
				if (pHeader->m_tables_file_size > (data_size - pHeader->m_tables_file_ofs))
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: file is corrupted or passed in buffer too small (5)\n");
					return false;
				}
			}
			else
			{
				if (!pHeader->m_endpoint_cb_file_size || !pHeader->m_selector_cb_file_size || !pHeader->m_tables_file_size)
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: file is corrupted (0)\n");
						return false;
				}

				if ((pHeader->m_endpoint_cb_file_ofs > data_size) || (pHeader->m_selector_cb_file_ofs > data_size) || (pHeader->m_tables_file_ofs > data_size))
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: file is corrupted or passed in buffer too small (1)\n");
					return false;
				}

				if (pHeader->m_endpoint_cb_file_size > (data_size - pHeader->m_endpoint_cb_file_ofs))
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: file is corrupted or passed in buffer too small (2)\n");
					return false;
				}

				if (pHeader->m_selector_cb_file_size > (data_size - pHeader->m_selector_cb_file_ofs))
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: file is corrupted or passed in buffer too small (3)\n");
					return false;
				}

				if (pHeader->m_tables_file_size > (data_size - pHeader->m_tables_file_ofs))
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: file is corrupted or passed in buffer too small (3)\n");
					return false;
				}

				if (!m_lowlevel_etc1s_decoder.decode_palettes(
					pHeader->m_total_endpoints, pDataU8 + pHeader->m_endpoint_cb_file_ofs, pHeader->m_endpoint_cb_file_size,
					pHeader->m_total_selectors, pDataU8 + pHeader->m_selector_cb_file_ofs, pHeader->m_selector_cb_file_size))
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: decode_palettes failed\n");
					return false;
				}
			}

			if (!m_lowlevel_etc1s_decoder.decode_tables(pDataU8 + pHeader->m_tables_file_ofs, pHeader->m_tables_file_size))
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: decode_tables failed\n");
				return false;
			}
		}
		else
		{
			// Nothing special to do for UASTC/UASTC HDR.
			if (m_lowlevel_etc1s_decoder.m_local_endpoints.size())
			{
				m_lowlevel_etc1s_decoder.clear();
			}
		}
		
		m_ready_to_transcode = true;

		return true;
	}

	bool basisu_transcoder::stop_transcoding()
	{
		m_lowlevel_etc1s_decoder.clear();

		m_ready_to_transcode = false;
		
		return true;
	}

	bool basisu_transcoder::transcode_slice(const void* pData, uint32_t data_size, uint32_t slice_index, void* pOutput_blocks, uint32_t output_blocks_buf_size_in_blocks_or_pixels, block_format fmt,
		uint32_t output_block_or_pixel_stride_in_bytes, uint32_t decode_flags, uint32_t output_row_pitch_in_blocks_or_pixels, basisu_transcoder_state* pState, void *pAlpha_blocks, uint32_t output_rows_in_pixels, int channel0, int channel1) const
	{
		if (!m_ready_to_transcode)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_slice: must call start_transcoding first\n");
			return false;
		}

		if (decode_flags & cDecodeFlagsPVRTCDecodeToNextPow2)
		{
			// TODO: Not yet supported
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_slice: cDecodeFlagsPVRTCDecodeToNextPow2 currently unsupported\n");
			return false;
		}

		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_slice: header validation failed\n");
			return false;
		}

		const basis_file_header* pHeader = reinterpret_cast<const basis_file_header*>(pData);

		const uint8_t* pDataU8 = static_cast<const uint8_t*>(pData);

		if (slice_index >= pHeader->m_total_slices)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_slice: slice_index >= pHeader->m_total_slices\n");
			return false;
		}

		const basis_slice_desc& slice_desc = reinterpret_cast<const basis_slice_desc*>(pDataU8 + pHeader->m_slice_desc_file_ofs)[slice_index];
										
		if (basis_block_format_is_uncompressed(fmt))
		{
			// Assume the output buffer is orig_width by orig_height
			if (!output_row_pitch_in_blocks_or_pixels)
				output_row_pitch_in_blocks_or_pixels = slice_desc.m_orig_width;

			if (!output_rows_in_pixels)
				output_rows_in_pixels = slice_desc.m_orig_height;

			// Now make sure the output buffer is large enough, or we'll overwrite memory.
			if (output_blocks_buf_size_in_blocks_or_pixels < (output_rows_in_pixels * output_row_pitch_in_blocks_or_pixels))
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::transcode_slice: output_blocks_buf_size_in_blocks_or_pixels < (output_rows_in_pixels * output_row_pitch_in_blocks_or_pixels)\n");
				return false;
			}
		}
		else if (fmt == block_format::cFXT1_RGB)
		{
			const uint32_t num_blocks_fxt1_x = (slice_desc.m_orig_width + 7) / 8;
			const uint32_t num_blocks_fxt1_y = (slice_desc.m_orig_height + 3) / 4;
			const uint32_t total_blocks_fxt1 = num_blocks_fxt1_x * num_blocks_fxt1_y;

			if (output_blocks_buf_size_in_blocks_or_pixels < total_blocks_fxt1)
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::transcode_slice: output_blocks_buf_size_in_blocks_or_pixels < total_blocks_fxt1\n");
				return false;
			}
		}
		else if (fmt == block_format::cASTC_HDR_6x6)
		{
			const uint32_t num_blocks_6x6_x = (slice_desc.m_orig_width + 5) / 6;
			const uint32_t num_blocks_6x6_y = (slice_desc.m_orig_height + 5) / 6;
			const uint32_t total_blocks_6x6 = num_blocks_6x6_x * num_blocks_6x6_y;

			if (output_blocks_buf_size_in_blocks_or_pixels < total_blocks_6x6)
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::transcode_slice: output_blocks_buf_size_in_blocks_or_pixels < total_blocks_6x6\n");
				return false;
			}
		}
		else
		{
			// must be a 4x4 pixel block format
			const uint32_t num_blocks_4x4_x = (slice_desc.m_orig_width + 3) / 4;
			const uint32_t num_blocks_4x4_y = (slice_desc.m_orig_height + 3) / 4;
			const uint32_t total_4x4_blocks = num_blocks_4x4_x * num_blocks_4x4_y;

			if (output_blocks_buf_size_in_blocks_or_pixels < total_4x4_blocks)
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::transcode_slice: output_blocks_buf_size_in_blocks_or_pixels < total_blocks\n");
				return false;
			}
		}

		if ((pHeader->m_tex_format == (uint32_t)basis_tex_format::cETC1S) || (pHeader->m_tex_format == (uint32_t)basis_tex_format::cUASTC4x4))
		{
			if ((fmt == block_format::cPVRTC1_4_RGB) || (fmt == block_format::cPVRTC1_4_RGBA))
			{
				if ((!basisu::is_pow2(slice_desc.m_num_blocks_x * 4)) || (!basisu::is_pow2(slice_desc.m_num_blocks_y * 4)))
				{
					// PVRTC1 only supports power of 2 dimensions
					BASISU_DEVEL_ERROR("basisu_transcoder::transcode_slice: PVRTC1 only supports power of 2 dimensions\n");
					return false;
				}
			}
		}

		if (slice_desc.m_file_ofs > data_size)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_slice: invalid slice_desc.m_file_ofs, or passed in buffer too small\n");
			return false;
		}

		const uint32_t data_size_left = data_size - slice_desc.m_file_ofs;
		if (data_size_left < slice_desc.m_file_size)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_slice: invalid slice_desc.m_file_size, or passed in buffer too small\n");
			return false;
		}
		
		if (pHeader->m_tex_format == (int)basis_tex_format::cASTC_HDR_6x6)
		{
			return m_lowlevel_astc_6x6_hdr_decoder.transcode_slice(pOutput_blocks, slice_desc.m_num_blocks_x, slice_desc.m_num_blocks_y,
				pDataU8 + slice_desc.m_file_ofs, slice_desc.m_file_size,
				fmt, output_block_or_pixel_stride_in_bytes, (decode_flags & cDecodeFlagsBC1ForbidThreeColorBlocks) == 0, *pHeader, slice_desc, output_row_pitch_in_blocks_or_pixels, pState,
				output_rows_in_pixels, channel0, channel1, decode_flags);
		}
		else if (pHeader->m_tex_format == (int)basis_tex_format::cASTC_HDR_6x6_INTERMEDIATE)
		{
			return m_lowlevel_astc_6x6_hdr_intermediate_decoder.transcode_slice(pOutput_blocks, slice_desc.m_num_blocks_x, slice_desc.m_num_blocks_y,
				pDataU8 + slice_desc.m_file_ofs, slice_desc.m_file_size,
				fmt, output_block_or_pixel_stride_in_bytes, (decode_flags & cDecodeFlagsBC1ForbidThreeColorBlocks) == 0, *pHeader, slice_desc, output_row_pitch_in_blocks_or_pixels, pState,
				output_rows_in_pixels, channel0, channel1, decode_flags);
		}
		else if (pHeader->m_tex_format == (int)basis_tex_format::cUASTC_HDR_4x4)
		{
			return m_lowlevel_uastc_4x4_hdr_decoder.transcode_slice(pOutput_blocks, slice_desc.m_num_blocks_x, slice_desc.m_num_blocks_y,
				pDataU8 + slice_desc.m_file_ofs, slice_desc.m_file_size,
				fmt, output_block_or_pixel_stride_in_bytes, (decode_flags & cDecodeFlagsBC1ForbidThreeColorBlocks) == 0, *pHeader, slice_desc, output_row_pitch_in_blocks_or_pixels, pState,
				output_rows_in_pixels, channel0, channel1, decode_flags);
		}
		else if (pHeader->m_tex_format == (int)basis_tex_format::cUASTC4x4)
		{
			return m_lowlevel_uastc_decoder.transcode_slice(pOutput_blocks, slice_desc.m_num_blocks_x, slice_desc.m_num_blocks_y,
				pDataU8 + slice_desc.m_file_ofs, slice_desc.m_file_size,
				fmt, output_block_or_pixel_stride_in_bytes, (decode_flags & cDecodeFlagsBC1ForbidThreeColorBlocks) == 0, *pHeader, slice_desc, output_row_pitch_in_blocks_or_pixels, pState,
				output_rows_in_pixels, channel0, channel1, decode_flags);
		}
		else
		{
			return m_lowlevel_etc1s_decoder.transcode_slice(pOutput_blocks, slice_desc.m_num_blocks_x, slice_desc.m_num_blocks_y,
				pDataU8 + slice_desc.m_file_ofs, slice_desc.m_file_size,
				fmt, output_block_or_pixel_stride_in_bytes, (decode_flags & cDecodeFlagsBC1ForbidThreeColorBlocks) == 0, *pHeader, slice_desc, output_row_pitch_in_blocks_or_pixels, pState,
				(decode_flags & cDecodeFlagsOutputHasAlphaIndices) != 0, pAlpha_blocks, output_rows_in_pixels);
		}
	}

	int basisu_transcoder::find_first_slice_index(const void* pData, uint32_t data_size, uint32_t image_index, uint32_t level_index) const
	{
		BASISU_NOTE_UNUSED(data_size);

		const basis_file_header* pHeader = reinterpret_cast<const basis_file_header*>(pData);
		const uint8_t* pDataU8 = static_cast<const uint8_t*>(pData);

		// For very large basis files this search could be painful
		// TODO: Binary search this
		for (uint32_t slice_iter = 0; slice_iter < pHeader->m_total_slices; slice_iter++)
		{
			const basis_slice_desc& slice_desc = reinterpret_cast<const basis_slice_desc*>(pDataU8 + pHeader->m_slice_desc_file_ofs)[slice_iter];
			if ((slice_desc.m_image_index == image_index) && (slice_desc.m_level_index == level_index))
				return slice_iter;
		}

		BASISU_DEVEL_ERROR("basisu_transcoder::find_first_slice_index: didn't find slice\n");

		return -1;
	}

	int basisu_transcoder::find_slice(const void* pData, uint32_t data_size, uint32_t image_index, uint32_t level_index, bool alpha_data) const
	{
		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::find_slice: header validation failed\n");
			return false;
		}

		const basis_file_header* pHeader = reinterpret_cast<const basis_file_header*>(pData);
		const uint8_t* pDataU8 = static_cast<const uint8_t*>(pData);
		const basis_slice_desc* pSlice_descs = reinterpret_cast<const basis_slice_desc*>(pDataU8 + pHeader->m_slice_desc_file_ofs);

		// For very large basis files this search could be painful
		// TODO: Binary search this
		for (uint32_t slice_iter = 0; slice_iter < pHeader->m_total_slices; slice_iter++)
		{
			const basis_slice_desc& slice_desc = pSlice_descs[slice_iter];
			if ((slice_desc.m_image_index == image_index) && (slice_desc.m_level_index == level_index))
			{
				if (pHeader->m_tex_format == (int)basis_tex_format::cETC1S)
				{
					const bool slice_alpha = (slice_desc.m_flags & cSliceDescFlagsHasAlpha) != 0;
					if (slice_alpha == alpha_data)
						return slice_iter;
				}
				else
				{
					return slice_iter;
				}
			}
		}

		BASISU_DEVEL_ERROR("basisu_transcoder::find_slice: didn't find slice\n");

		return -1;
	}

	void basisu_transcoder::write_opaque_alpha_blocks(
		uint32_t num_blocks_x, uint32_t num_blocks_y,
		void* pOutput_blocks, block_format fmt,
		uint32_t block_stride_in_bytes, uint32_t output_row_pitch_in_blocks_or_pixels)
	{
		// 'num_blocks_y', 'pOutput_blocks' & 'block_stride_in_bytes' unused
		// when disabling BASISD_SUPPORT_ETC2_EAC_A8 *and* BASISD_SUPPORT_DXT5A
		BASISU_NOTE_UNUSED(num_blocks_y);
		BASISU_NOTE_UNUSED(pOutput_blocks);
		BASISU_NOTE_UNUSED(block_stride_in_bytes);

		if (!output_row_pitch_in_blocks_or_pixels)
			output_row_pitch_in_blocks_or_pixels = num_blocks_x;
				
		if ((fmt == block_format::cETC2_EAC_A8) || (fmt == block_format::cETC2_EAC_R11))
		{
#if BASISD_SUPPORT_ETC2_EAC_A8
			eac_block blk;
			blk.m_base = 255;
			blk.m_multiplier = 1;
			blk.m_table = 13;

			// Selectors are all 4's
			memcpy(&blk.m_selectors, g_etc2_eac_a8_sel4, sizeof(g_etc2_eac_a8_sel4));

			for (uint32_t y = 0; y < num_blocks_y; y++)
			{
				uint32_t dst_ofs = y * output_row_pitch_in_blocks_or_pixels * block_stride_in_bytes;
				for (uint32_t x = 0; x < num_blocks_x; x++)
				{
					memcpy((uint8_t*)pOutput_blocks + dst_ofs, &blk, sizeof(blk));
					dst_ofs += block_stride_in_bytes;
				}
			}
#endif
		}
		else if (fmt == block_format::cBC4)
		{
#if BASISD_SUPPORT_DXT5A
			dxt5a_block blk;
			blk.m_endpoints[0] = 255;
			blk.m_endpoints[1] = 255;
			memset(blk.m_selectors, 0, sizeof(blk.m_selectors));

			for (uint32_t y = 0; y < num_blocks_y; y++)
			{
				uint32_t dst_ofs = y * output_row_pitch_in_blocks_or_pixels * block_stride_in_bytes;
				for (uint32_t x = 0; x < num_blocks_x; x++)
				{
					memcpy((uint8_t*)pOutput_blocks + dst_ofs, &blk, sizeof(blk));
					dst_ofs += block_stride_in_bytes;
				}
			}
#endif
		}
	}

	bool basisu_transcoder::transcode_image_level(
		const void* pData, uint32_t data_size,
		uint32_t image_index, uint32_t level_index,
		void* pOutput_blocks, uint32_t output_blocks_buf_size_in_blocks_or_pixels,
		transcoder_texture_format fmt,
		uint32_t decode_flags, uint32_t output_row_pitch_in_blocks_or_pixels, basisu_transcoder_state *pState, uint32_t output_rows_in_pixels) const
	{
		const uint32_t bytes_per_block_or_pixel = basis_get_bytes_per_block_or_pixel(fmt);

		if (!m_ready_to_transcode)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_image_level: must call start_transcoding() first\n");
			return false;
		}

		//const bool transcode_alpha_data_to_opaque_formats = (decode_flags & cDecodeFlagsTranscodeAlphaDataToOpaqueFormats) != 0;

		if (decode_flags & cDecodeFlagsPVRTCDecodeToNextPow2)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_image_level: cDecodeFlagsPVRTCDecodeToNextPow2 currently unsupported\n");
			// TODO: Not yet supported
			return false;
		}

		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_image_level: header validation failed\n");
			return false;
		}

		const basis_file_header* pHeader = reinterpret_cast<const basis_file_header*>(pData);

		const uint8_t* pDataU8 = static_cast<const uint8_t*>(pData);

		const basis_slice_desc* pSlice_descs = reinterpret_cast<const basis_slice_desc*>(pDataU8 + pHeader->m_slice_desc_file_ofs);

		const bool basis_file_has_alpha_slices = (pHeader->m_flags & cBASISHeaderFlagHasAlphaSlices) != 0;

		int slice_index = find_first_slice_index(pData, data_size, image_index, level_index);
		if (slice_index < 0)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_image_level: failed finding slice index\n");
			// Unable to find the requested image/level 
			return false;
		}

		if ((fmt == transcoder_texture_format::cTFPVRTC1_4_RGBA) && (!basis_file_has_alpha_slices))
		{
			// Switch to PVRTC1 RGB if the input doesn't have alpha.
			fmt = transcoder_texture_format::cTFPVRTC1_4_RGB;
		}
				
		if (pHeader->m_tex_format == (int)basis_tex_format::cETC1S)
		{
			if (pSlice_descs[slice_index].m_flags & cSliceDescFlagsHasAlpha)
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::transcode_image_level: alpha basis file has out of order alpha slice\n");

				// The first slice shouldn't have alpha data in a properly formed basis file
				return false;
			}

			if (basis_file_has_alpha_slices)
			{
				// The alpha data should immediately follow the color data, and have the same resolution.
				if ((slice_index + 1U) >= pHeader->m_total_slices)
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::transcode_image_level: alpha basis file has missing alpha slice\n");
					// basis file is missing the alpha slice
					return false;
				}

				// Basic sanity checks
				if ((pSlice_descs[slice_index + 1].m_flags & cSliceDescFlagsHasAlpha) == 0)
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::transcode_image_level: alpha basis file has missing alpha slice (flag check)\n");
					// This slice should have alpha data
					return false;
				}

				if ((pSlice_descs[slice_index].m_num_blocks_x != pSlice_descs[slice_index + 1].m_num_blocks_x) || (pSlice_descs[slice_index].m_num_blocks_y != pSlice_descs[slice_index + 1].m_num_blocks_y))
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::transcode_image_level: alpha basis file slice dimensions bad\n");
					// Alpha slice should have been the same res as the color slice
					return false;
				}
			}
		}
								
		bool status = false;

		if ((pHeader->m_tex_format == (int)basis_tex_format::cETC1S) || (pHeader->m_tex_format == (int)basis_tex_format::cUASTC4x4))
		{
			// Only do this on 4x4 LDR formats that supports transcoding to PVRTC1.
			const uint32_t total_slice_blocks = pSlice_descs[slice_index].m_num_blocks_x * pSlice_descs[slice_index].m_num_blocks_y;

			if (((fmt == transcoder_texture_format::cTFPVRTC1_4_RGB) || (fmt == transcoder_texture_format::cTFPVRTC1_4_RGBA)) && (output_blocks_buf_size_in_blocks_or_pixels > total_slice_blocks))
			{
				// The transcoder doesn't write beyond total_slice_blocks, so we need to clear the rest ourselves.
				// For GL usage, PVRTC1 4bpp image size is (max(width, 8)* max(height, 8) * 4 + 7) / 8. 
				// However, for KTX and internally in Basis this formula isn't used, it's just ((width+3)/4) * ((height+3)/4) * bytes_per_block_or_pixel. This is all the transcoder actually writes to memory.
				memset(static_cast<uint8_t*>(pOutput_blocks) + total_slice_blocks * bytes_per_block_or_pixel, 0, (output_blocks_buf_size_in_blocks_or_pixels - total_slice_blocks) * bytes_per_block_or_pixel);
			}
		}
		
		if (pHeader->m_tex_format == (int)basis_tex_format::cASTC_HDR_6x6)
		{
			const basis_slice_desc* pSlice_desc = &pSlice_descs[slice_index];

			// Use the container independent image transcode method.
			status = m_lowlevel_astc_6x6_hdr_decoder.transcode_image(fmt,
				pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels,
				(const uint8_t*)pData, data_size, pSlice_desc->m_num_blocks_x, pSlice_desc->m_num_blocks_y, pSlice_desc->m_orig_width, pSlice_desc->m_orig_height, pSlice_desc->m_level_index,
				pSlice_desc->m_file_ofs, pSlice_desc->m_file_size,
				decode_flags, basis_file_has_alpha_slices, pHeader->m_tex_type == cBASISTexTypeVideoFrames, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels);
		}
		else if (pHeader->m_tex_format == (int)basis_tex_format::cASTC_HDR_6x6_INTERMEDIATE)
		{
			const basis_slice_desc* pSlice_desc = &pSlice_descs[slice_index];

			// Use the container independent image transcode method.
			status = m_lowlevel_astc_6x6_hdr_intermediate_decoder.transcode_image(fmt,
				pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels,
				(const uint8_t*)pData, data_size, pSlice_desc->m_num_blocks_x, pSlice_desc->m_num_blocks_y, pSlice_desc->m_orig_width, pSlice_desc->m_orig_height, pSlice_desc->m_level_index,
				pSlice_desc->m_file_ofs, pSlice_desc->m_file_size,
				decode_flags, basis_file_has_alpha_slices, pHeader->m_tex_type == cBASISTexTypeVideoFrames, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels);
		}
		else if (pHeader->m_tex_format == (int)basis_tex_format::cUASTC_HDR_4x4)
		{
			const basis_slice_desc* pSlice_desc = &pSlice_descs[slice_index];

			// Use the container independent image transcode method.
			status = m_lowlevel_uastc_4x4_hdr_decoder.transcode_image(fmt,
				pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels,
				(const uint8_t*)pData, data_size, pSlice_desc->m_num_blocks_x, pSlice_desc->m_num_blocks_y, pSlice_desc->m_orig_width, pSlice_desc->m_orig_height, pSlice_desc->m_level_index,
				pSlice_desc->m_file_ofs, pSlice_desc->m_file_size,
				decode_flags, basis_file_has_alpha_slices, pHeader->m_tex_type == cBASISTexTypeVideoFrames, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels);
		}
		else if (pHeader->m_tex_format == (int)basis_tex_format::cUASTC4x4)
		{
			const basis_slice_desc* pSlice_desc = &pSlice_descs[slice_index];

			// Use the container independent image transcode method.
			status = m_lowlevel_uastc_decoder.transcode_image(fmt,
				pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels,
				(const uint8_t*)pData, data_size, pSlice_desc->m_num_blocks_x, pSlice_desc->m_num_blocks_y, pSlice_desc->m_orig_width, pSlice_desc->m_orig_height, pSlice_desc->m_level_index,
				pSlice_desc->m_file_ofs, pSlice_desc->m_file_size,
				decode_flags, basis_file_has_alpha_slices, pHeader->m_tex_type == cBASISTexTypeVideoFrames, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels);
		}
		else 
		{
			// ETC1S
			const basis_slice_desc* pSlice_desc = &pSlice_descs[slice_index];
			const basis_slice_desc* pAlpha_slice_desc = basis_file_has_alpha_slices ? &pSlice_descs[slice_index + 1] : nullptr;

			assert((pSlice_desc->m_flags & cSliceDescFlagsHasAlpha) == 0);

			if (pAlpha_slice_desc)
			{
				// Basic sanity checks
				assert((pAlpha_slice_desc->m_flags & cSliceDescFlagsHasAlpha) != 0);
				assert(pSlice_desc->m_num_blocks_x == pAlpha_slice_desc->m_num_blocks_x);
				assert(pSlice_desc->m_num_blocks_y == pAlpha_slice_desc->m_num_blocks_y);
				assert(pSlice_desc->m_level_index == pAlpha_slice_desc->m_level_index);
			}

			// Use the container independent image transcode method.
			status = m_lowlevel_etc1s_decoder.transcode_image(fmt,
				pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels,
				(const uint8_t *)pData, data_size, pSlice_desc->m_num_blocks_x, pSlice_desc->m_num_blocks_y, pSlice_desc->m_orig_width, pSlice_desc->m_orig_height, pSlice_desc->m_level_index,
				pSlice_desc->m_file_ofs, pSlice_desc->m_file_size,
				(pAlpha_slice_desc != nullptr) ? (uint32_t)pAlpha_slice_desc->m_file_ofs : 0U, (pAlpha_slice_desc != nullptr) ? (uint32_t)pAlpha_slice_desc->m_file_size : 0U,
				decode_flags, basis_file_has_alpha_slices, pHeader->m_tex_type == cBASISTexTypeVideoFrames, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels);

		} // if (pHeader->m_tex_format == (int)basis_tex_format::cUASTC4x4)
      
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_image_level: Returning false\n");
		}
		else
		{
			//BASISU_DEVEL_ERROR("basisu_transcoder::transcode_image_level: Returning true\n");      
		}

		return status;
	}

	uint32_t basis_get_bytes_per_block_or_pixel(transcoder_texture_format fmt)
	{
		switch (fmt)
		{
		case transcoder_texture_format::cTFETC1_RGB:
		case transcoder_texture_format::cTFBC1_RGB:
		case transcoder_texture_format::cTFBC4_R:
		case transcoder_texture_format::cTFPVRTC1_4_RGB:
		case transcoder_texture_format::cTFPVRTC1_4_RGBA:
		case transcoder_texture_format::cTFATC_RGB:
		case transcoder_texture_format::cTFPVRTC2_4_RGB:
		case transcoder_texture_format::cTFPVRTC2_4_RGBA:
		case transcoder_texture_format::cTFETC2_EAC_R11:
			return 8;
		case transcoder_texture_format::cTFBC7_RGBA:
		case transcoder_texture_format::cTFBC7_ALT:
		case transcoder_texture_format::cTFBC6H:
		case transcoder_texture_format::cTFETC2_RGBA:
		case transcoder_texture_format::cTFBC3_RGBA:
		case transcoder_texture_format::cTFBC5_RG:
		case transcoder_texture_format::cTFASTC_4x4_RGBA:
		case transcoder_texture_format::cTFASTC_HDR_4x4_RGBA:
		case transcoder_texture_format::cTFASTC_HDR_6x6_RGBA:
		case transcoder_texture_format::cTFATC_RGBA:
		case transcoder_texture_format::cTFFXT1_RGB:
		case transcoder_texture_format::cTFETC2_EAC_RG11:
			return 16;
		case transcoder_texture_format::cTFRGBA32:
		case transcoder_texture_format::cTFRGB_9E5:
			return sizeof(uint32_t);
		case transcoder_texture_format::cTFRGB565:
		case transcoder_texture_format::cTFBGR565:
		case transcoder_texture_format::cTFRGBA4444:
			return sizeof(uint16_t);
		case transcoder_texture_format::cTFRGB_HALF:
			return sizeof(half_float) * 3;
		case transcoder_texture_format::cTFRGBA_HALF:
			return sizeof(half_float) * 4;
		default:
			assert(0);
			BASISU_DEVEL_ERROR("basis_get_basisu_texture_format: Invalid fmt\n");
			break;
		}
		return 0;
	}

	const char* basis_get_format_name(transcoder_texture_format fmt)
	{
		switch (fmt)
		{
		case transcoder_texture_format::cTFETC1_RGB: return "ETC1_RGB";
		case transcoder_texture_format::cTFBC1_RGB: return "BC1_RGB";
		case transcoder_texture_format::cTFBC4_R: return "BC4_R";
		case transcoder_texture_format::cTFPVRTC1_4_RGB: return "PVRTC1_4_RGB";
		case transcoder_texture_format::cTFPVRTC1_4_RGBA: return "PVRTC1_4_RGBA";
		case transcoder_texture_format::cTFBC7_RGBA: return "BC7_RGBA";
		case transcoder_texture_format::cTFBC7_ALT: return "BC7_RGBA";
		case transcoder_texture_format::cTFETC2_RGBA: return "ETC2_RGBA";
		case transcoder_texture_format::cTFBC3_RGBA: return "BC3_RGBA";
		case transcoder_texture_format::cTFBC5_RG: return "BC5_RG";
		case transcoder_texture_format::cTFASTC_4x4_RGBA: return "ASTC_RGBA";
		case transcoder_texture_format::cTFASTC_HDR_4x4_RGBA: return "ASTC_HDR_4X4_RGBA";
		case transcoder_texture_format::cTFASTC_HDR_6x6_RGBA: return "ASTC_HDR_6X6_RGBA";
		case transcoder_texture_format::cTFATC_RGB: return "ATC_RGB";
		case transcoder_texture_format::cTFATC_RGBA: return "ATC_RGBA";
		case transcoder_texture_format::cTFRGBA32: return "RGBA32";
		case transcoder_texture_format::cTFRGB565: return "RGB565";
		case transcoder_texture_format::cTFBGR565: return "BGR565";
		case transcoder_texture_format::cTFRGBA4444: return "RGBA4444";
		case transcoder_texture_format::cTFRGBA_HALF: return "RGBA_HALF";
		case transcoder_texture_format::cTFRGB_9E5: return "RGB_9E5";
		case transcoder_texture_format::cTFRGB_HALF: return "RGB_HALF";
		case transcoder_texture_format::cTFFXT1_RGB: return "FXT1_RGB";
		case transcoder_texture_format::cTFPVRTC2_4_RGB: return "PVRTC2_4_RGB";
		case transcoder_texture_format::cTFPVRTC2_4_RGBA: return "PVRTC2_4_RGBA";
		case transcoder_texture_format::cTFETC2_EAC_R11: return "ETC2_EAC_R11";
		case transcoder_texture_format::cTFETC2_EAC_RG11: return "ETC2_EAC_RG11";
		case transcoder_texture_format::cTFBC6H: return "BC6H";
		default:
			assert(0);
			BASISU_DEVEL_ERROR("basis_get_basisu_texture_format: Invalid fmt\n");
			break;
		}
		return "";
	}

	const char* basis_get_block_format_name(block_format fmt)
	{
		switch (fmt)
		{
		case block_format::cETC1: return "ETC1";
		case block_format::cBC1: return "BC1";
		case block_format::cPVRTC1_4_RGB: return "PVRTC1_4_RGB";
		case block_format::cPVRTC1_4_RGBA: return "PVRTC1_4_RGBA";
		case block_format::cBC7: return "BC7";
		case block_format::cETC2_RGBA: return "ETC2_RGBA";
		case block_format::cBC3: return "BC3";
		case block_format::cASTC_4x4: return "ASTC_4x4";
		case block_format::cATC_RGB: return "ATC_RGB";
		case block_format::cRGBA32: return "RGBA32";
		case block_format::cRGB565: return "RGB565";
		case block_format::cBGR565: return "BGR565";
		case block_format::cRGBA4444: return "RGBA4444";
		case block_format::cRGBA_HALF: return "RGBA_HALF";
		case block_format::cRGB_HALF: return "RGB_HALF";
		case block_format::cRGB_9E5: return "RGB_9E5";
		case block_format::cUASTC_4x4: return "UASTC_4x4";
		case block_format::cUASTC_HDR_4x4: return "UASTC_HDR_4x4";
		case block_format::cBC6H: return "BC6H";
		case block_format::cASTC_HDR_4x4: return "ASTC_HDR_4x4";
		case block_format::cASTC_HDR_6x6: return "ASTC_HDR_6x6";
		case block_format::cFXT1_RGB: return "FXT1_RGB";
		case block_format::cPVRTC2_4_RGB: return "PVRTC2_4_RGB";
		case block_format::cPVRTC2_4_RGBA: return "PVRTC2_4_RGBA";
		case block_format::cETC2_EAC_R11: return "ETC2_EAC_R11";
		case block_format::cETC2_EAC_RG11: return "ETC2_EAC_RG11";
		default:
			assert(0);
			BASISU_DEVEL_ERROR("basis_get_basisu_texture_format: Invalid fmt\n");
		break;
		}
		return "";
	}

	const char* basis_get_texture_type_name(basis_texture_type tex_type)
	{
		switch (tex_type)
		{
		case cBASISTexType2D: return "2D";
		case cBASISTexType2DArray: return "2D array";
		case cBASISTexTypeCubemapArray: return "cubemap array";
		case cBASISTexTypeVideoFrames: return "video";
		case cBASISTexTypeVolume: return "3D";
		default:
			assert(0);
			BASISU_DEVEL_ERROR("basis_get_texture_type_name: Invalid tex_type\n");
			break;
		}
		return "";
	}

	bool basis_transcoder_format_has_alpha(transcoder_texture_format fmt)
	{
		// TODO: Technically ASTC HDR does support alpha, but our ASTC HDR encoders don't yet support it. Unsure what to do here.
		switch (fmt)
		{
		case transcoder_texture_format::cTFETC2_RGBA:
		case transcoder_texture_format::cTFBC3_RGBA:
		case transcoder_texture_format::cTFASTC_4x4_RGBA:
		case transcoder_texture_format::cTFASTC_HDR_4x4_RGBA: // technically this ASTC HDR format supports alpha, but we currently don't exploit that in our encoders
		case transcoder_texture_format::cTFASTC_HDR_6x6_RGBA: // technically this ASTC HDR format supports alpha, but we currently don't exploit that in our encoders
		case transcoder_texture_format::cTFBC7_RGBA:
		case transcoder_texture_format::cTFBC7_ALT:
		case transcoder_texture_format::cTFPVRTC1_4_RGBA:
		case transcoder_texture_format::cTFPVRTC2_4_RGBA:
		case transcoder_texture_format::cTFATC_RGBA:
		case transcoder_texture_format::cTFRGBA32:
		case transcoder_texture_format::cTFRGBA4444:
		case transcoder_texture_format::cTFRGBA_HALF:
			return true;
		default:
			break;
		}
		return false;
	}

	bool basis_transcoder_format_is_hdr(transcoder_texture_format fmt)
	{
		switch (fmt)
		{
		case transcoder_texture_format::cTFASTC_HDR_4x4_RGBA:
		case transcoder_texture_format::cTFASTC_HDR_6x6_RGBA:
		case transcoder_texture_format::cTFBC6H:
		case transcoder_texture_format::cTFRGBA_HALF:
		case transcoder_texture_format::cTFRGB_HALF:
		case transcoder_texture_format::cTFRGB_9E5:
			return true;
		default:
			break;
		}
		return false;
	}

	basisu::texture_format basis_get_basisu_texture_format(transcoder_texture_format fmt)
	{
		switch (fmt)
		{
		case transcoder_texture_format::cTFETC1_RGB: return basisu::texture_format::cETC1;
		case transcoder_texture_format::cTFBC1_RGB: return basisu::texture_format::cBC1;
		case transcoder_texture_format::cTFBC4_R: return basisu::texture_format::cBC4;
		case transcoder_texture_format::cTFPVRTC1_4_RGB: return basisu::texture_format::cPVRTC1_4_RGB;
		case transcoder_texture_format::cTFPVRTC1_4_RGBA: return basisu::texture_format::cPVRTC1_4_RGBA;
		case transcoder_texture_format::cTFBC7_RGBA: return basisu::texture_format::cBC7;
		case transcoder_texture_format::cTFBC7_ALT: return basisu::texture_format::cBC7;
		case transcoder_texture_format::cTFETC2_RGBA: return basisu::texture_format::cETC2_RGBA;
		case transcoder_texture_format::cTFBC3_RGBA: return basisu::texture_format::cBC3;
		case transcoder_texture_format::cTFBC5_RG: return basisu::texture_format::cBC5;
		case transcoder_texture_format::cTFASTC_4x4_RGBA: return basisu::texture_format::cASTC_LDR_4x4;
		case transcoder_texture_format::cTFASTC_HDR_4x4_RGBA: return basisu::texture_format::cASTC_HDR_4x4;
		case transcoder_texture_format::cTFASTC_HDR_6x6_RGBA: return basisu::texture_format::cASTC_HDR_6x6;
		case transcoder_texture_format::cTFBC6H: return basisu::texture_format::cBC6HUnsigned;
		case transcoder_texture_format::cTFATC_RGB: return basisu::texture_format::cATC_RGB;
		case transcoder_texture_format::cTFATC_RGBA: return basisu::texture_format::cATC_RGBA_INTERPOLATED_ALPHA;
		case transcoder_texture_format::cTFRGBA32: return basisu::texture_format::cRGBA32;
		case transcoder_texture_format::cTFRGB565: return basisu::texture_format::cRGB565;
		case transcoder_texture_format::cTFBGR565: return basisu::texture_format::cBGR565;
		case transcoder_texture_format::cTFRGBA4444: return basisu::texture_format::cRGBA4444;
		case transcoder_texture_format::cTFRGBA_HALF: return basisu::texture_format::cRGBA_HALF;
		case transcoder_texture_format::cTFRGB_9E5: return basisu::texture_format::cRGB_9E5;
		case transcoder_texture_format::cTFRGB_HALF: return basisu::texture_format::cRGB_HALF;
		case transcoder_texture_format::cTFFXT1_RGB: return basisu::texture_format::cFXT1_RGB;
		case transcoder_texture_format::cTFPVRTC2_4_RGB: return basisu::texture_format::cPVRTC2_4_RGBA;
		case transcoder_texture_format::cTFPVRTC2_4_RGBA: return basisu::texture_format::cPVRTC2_4_RGBA;
		case transcoder_texture_format::cTFETC2_EAC_R11: return basisu::texture_format::cETC2_R11_EAC;
		case transcoder_texture_format::cTFETC2_EAC_RG11: return basisu::texture_format::cETC2_RG11_EAC;
		default:
			assert(0);
			BASISU_DEVEL_ERROR("basis_get_basisu_texture_format: Invalid fmt\n");
			break;
		}
		return basisu::texture_format::cInvalidTextureFormat;
	}

	bool basis_transcoder_format_is_uncompressed(transcoder_texture_format tex_type)
	{
		switch (tex_type)
		{
		case transcoder_texture_format::cTFRGBA32:
		case transcoder_texture_format::cTFRGB565:
		case transcoder_texture_format::cTFBGR565:
		case transcoder_texture_format::cTFRGBA4444:
		case transcoder_texture_format::cTFRGB_HALF:
		case transcoder_texture_format::cTFRGBA_HALF:
		case transcoder_texture_format::cTFRGB_9E5:
			return true;
		default:
			break;
		}
		return false;
	}

	bool basis_block_format_is_uncompressed(block_format blk_fmt)
	{
		switch (blk_fmt)
		{
		case block_format::cRGB32:
		case block_format::cRGBA32:
		case block_format::cA32:
		case block_format::cRGB565:
		case block_format::cBGR565:
		case block_format::cRGBA4444:
		case block_format::cRGBA4444_COLOR:
		case block_format::cRGBA4444_ALPHA:
		case block_format::cRGBA4444_COLOR_OPAQUE:
		case block_format::cRGBA_HALF:
		case block_format::cRGB_HALF:
		case block_format::cRGB_9E5:
			return true;
		default:
			break;
		}
		return false;
	}
	
	uint32_t basis_get_uncompressed_bytes_per_pixel(transcoder_texture_format fmt)
	{
		switch (fmt)
		{
		case transcoder_texture_format::cTFRGBA32:
		case transcoder_texture_format::cTFRGB_9E5:
			return sizeof(uint32_t); 
		case transcoder_texture_format::cTFRGB565:
		case transcoder_texture_format::cTFBGR565:
		case transcoder_texture_format::cTFRGBA4444:
			return sizeof(uint16_t);
		case transcoder_texture_format::cTFRGB_HALF:
			return sizeof(half_float) * 3;
		case transcoder_texture_format::cTFRGBA_HALF:
			return sizeof(half_float) * 4;
		default:
			break;
		}
		return 0;
	}
	
	uint32_t basis_get_block_width(transcoder_texture_format tex_type)
	{
		switch (tex_type)
		{
			case transcoder_texture_format::cTFFXT1_RGB:
				return 8;
			case transcoder_texture_format::cTFASTC_HDR_6x6_RGBA:
				return 6;
			default:
				break;
		}
		return 4;
	}

	uint32_t basis_get_block_height(transcoder_texture_format tex_type)
	{
		switch (tex_type)
		{
		case transcoder_texture_format::cTFASTC_HDR_6x6_RGBA:
			return 6;
		default:
			break;
		}
		return 4;
	}

	uint32_t basis_tex_format_get_block_width(basis_tex_format fmt)
	{
		switch (fmt)
		{
		case basis_tex_format::cASTC_HDR_6x6:
		case basis_tex_format::cASTC_HDR_6x6_INTERMEDIATE:
			return 6;
		default:
			break;
		}
		return 4;
	}

	uint32_t basis_tex_format_get_block_height(basis_tex_format fmt)
	{
		switch (fmt)
		{
		case basis_tex_format::cASTC_HDR_6x6:
		case basis_tex_format::cASTC_HDR_6x6_INTERMEDIATE:
			return 6;
		default:
			break;
		}
		return 4;
	}

	bool basis_tex_format_is_hdr(basis_tex_format fmt)
	{
		switch (fmt)
		{
		case basis_tex_format::cUASTC_HDR_4x4:
		case basis_tex_format::cASTC_HDR_6x6:
		case basis_tex_format::cASTC_HDR_6x6_INTERMEDIATE:
			return true;
		default:
			break;
		}
		return false;
	}
	
	bool basis_is_format_supported(transcoder_texture_format tex_type, basis_tex_format fmt)
	{
		if ((fmt == basis_tex_format::cASTC_HDR_6x6) || (fmt == basis_tex_format::cASTC_HDR_6x6_INTERMEDIATE))
		{
			// RDO UASTC HDR 6x6, or our custom intermediate format
#if BASISD_SUPPORT_UASTC_HDR
			switch (tex_type)
			{
			case transcoder_texture_format::cTFASTC_HDR_6x6_RGBA:
			case transcoder_texture_format::cTFBC6H:
			case transcoder_texture_format::cTFRGBA_HALF:
			case transcoder_texture_format::cTFRGB_HALF:
			case transcoder_texture_format::cTFRGB_9E5:
				return true;
			default:
				break;
			}
#endif
		}
		else if (fmt == basis_tex_format::cUASTC_HDR_4x4)
		{
			// UASTC HDR 4x4
#if BASISD_SUPPORT_UASTC_HDR
			switch (tex_type)
			{
			case transcoder_texture_format::cTFASTC_HDR_4x4_RGBA:
			case transcoder_texture_format::cTFBC6H:
			case transcoder_texture_format::cTFRGBA_HALF:
			case transcoder_texture_format::cTFRGB_HALF:
			case transcoder_texture_format::cTFRGB_9E5:
				return true;
			default:
				break;
			}
#endif
		}
		else if (fmt == basis_tex_format::cUASTC4x4)
		{
			// UASTC LDR 4x4
#if BASISD_SUPPORT_UASTC
			switch (tex_type)
			{
			// These niche formats aren't currently supported for UASTC - everything else is.
			case transcoder_texture_format::cTFPVRTC2_4_RGB:
			case transcoder_texture_format::cTFPVRTC2_4_RGBA:
			case transcoder_texture_format::cTFATC_RGB:
			case transcoder_texture_format::cTFATC_RGBA:
			case transcoder_texture_format::cTFFXT1_RGB:
			// UASTC LDR doesn't support transcoding to HDR formats
			case transcoder_texture_format::cTFASTC_HDR_4x4_RGBA:
			case transcoder_texture_format::cTFASTC_HDR_6x6_RGBA:
			case transcoder_texture_format::cTFBC6H:
			case transcoder_texture_format::cTFRGBA_HALF:
			case transcoder_texture_format::cTFRGB_HALF:
			case transcoder_texture_format::cTFRGB_9E5:
				return false;
			default:
				return true;
			}
#endif
		}
		else
		{
			// ETC1S
			switch (tex_type)
			{
				// ETC1 and uncompressed are always supported.
			case transcoder_texture_format::cTFETC1_RGB:
			case transcoder_texture_format::cTFRGBA32:
			case transcoder_texture_format::cTFRGB565:
			case transcoder_texture_format::cTFBGR565:
			case transcoder_texture_format::cTFRGBA4444:
				return true;
#if BASISD_SUPPORT_DXT1
			case transcoder_texture_format::cTFBC1_RGB:
				return true;
#endif
#if BASISD_SUPPORT_DXT5A
			case transcoder_texture_format::cTFBC4_R:
			case transcoder_texture_format::cTFBC5_RG:
				return true;
#endif
#if BASISD_SUPPORT_DXT1 && BASISD_SUPPORT_DXT5A
			case transcoder_texture_format::cTFBC3_RGBA:
				return true;
#endif
#if BASISD_SUPPORT_PVRTC1
			case transcoder_texture_format::cTFPVRTC1_4_RGB:
			case transcoder_texture_format::cTFPVRTC1_4_RGBA:
				return true;
#endif
#if BASISD_SUPPORT_BC7_MODE5
			case transcoder_texture_format::cTFBC7_RGBA:
			case transcoder_texture_format::cTFBC7_ALT:
				return true;
#endif
#if BASISD_SUPPORT_ETC2_EAC_A8
			case transcoder_texture_format::cTFETC2_RGBA:
				return true;
#endif
#if BASISD_SUPPORT_ASTC		
			case transcoder_texture_format::cTFASTC_4x4_RGBA:
				return true;
#endif
#if BASISD_SUPPORT_ATC
			case transcoder_texture_format::cTFATC_RGB:
			case transcoder_texture_format::cTFATC_RGBA:
				return true;
#endif
#if BASISD_SUPPORT_FXT1
			case transcoder_texture_format::cTFFXT1_RGB:
				return true;
#endif
#if BASISD_SUPPORT_PVRTC2
			case transcoder_texture_format::cTFPVRTC2_4_RGB:
			case transcoder_texture_format::cTFPVRTC2_4_RGBA:
				return true;
#endif
#if BASISD_SUPPORT_ETC2_EAC_RG11
			case transcoder_texture_format::cTFETC2_EAC_R11:
			case transcoder_texture_format::cTFETC2_EAC_RG11:
				return true;
#endif
			default:
				break;
			}
		}

		return false;
	}

	// ------------------------------------------------------------------------------------------------------ 
	// UASTC LDR 4x4
	// ------------------------------------------------------------------------------------------------------ 

#if BASISD_SUPPORT_UASTC
	const astc_bc7_common_partition2_desc g_astc_bc7_common_partitions2[TOTAL_ASTC_BC7_COMMON_PARTITIONS2] =
	{
		{ 0, 28, false  }, { 1, 20, false }, { 2, 16, true }, { 3, 29, false },
		{ 4, 91, true }, { 5, 9, false }, { 6, 107, true }, { 7, 72, true },
		{ 8, 149, false }, { 9, 204, true }, { 10, 50, false }, { 11, 114, true },
		{ 12, 496, true }, { 13, 17, true }, { 14, 78, false }, { 15, 39, true },
		{ 17, 252, true }, { 18, 828, true }, { 19, 43, false }, { 20, 156, false },
		{ 21, 116, false }, { 22, 210, true }, { 23, 476, true }, { 24, 273, false },
		{ 25, 684, true }, { 26, 359, false }, { 29, 246, true }, { 32, 195, true },
		{ 33, 694, true }, { 52, 524, true }
	};

	const bc73_astc2_common_partition_desc g_bc7_3_astc2_common_partitions[TOTAL_BC7_3_ASTC2_COMMON_PARTITIONS] =
	{
		{ 10, 36, 4 }, { 11, 48, 4 },	{ 0, 61, 3 }, { 2, 137, 4 },
		{ 8, 161, 5 }, { 13, 183, 4 }, { 1, 226, 2 }, { 33, 281, 2 },
		{ 40, 302, 3 }, { 20, 307, 4 }, { 21, 479, 0 }, { 58, 495, 3 },
		{ 3, 593, 0 }, { 32, 594, 2 }, { 59, 605, 1 }, { 34, 799, 3 },
		{ 20, 812, 1 }, { 14, 988, 4 }, { 31, 993, 3 }
	};

	const astc_bc7_common_partition3_desc g_astc_bc7_common_partitions3[TOTAL_ASTC_BC7_COMMON_PARTITIONS3] =
	{
		{ 4, 260, 0 }, { 8, 74, 5 }, { 9, 32, 5 }, { 10, 156, 2 },
		{ 11, 183, 2 }, { 12, 15, 0 }, { 13, 745, 4 }, { 20, 0, 1 },
		{ 35, 335, 1 }, { 36, 902, 5 }, { 57, 254, 0 }
	};

	const uint8_t g_astc_to_bc7_partition_index_perm_tables[6][3] = { { 0, 1, 2 }, { 1, 2, 0 }, { 2, 0, 1 },	{ 2, 1, 0 }, { 0, 2, 1 }, { 1, 0, 2 } };

	const uint8_t g_bc7_to_astc_partition_index_perm_tables[6][3] = { { 0, 1, 2 }, { 2, 0, 1 }, { 1, 2, 0 },	{ 2, 1, 0 }, { 0, 2, 1 }, { 1, 0, 2 } };

	uint32_t bc7_convert_partition_index_3_to_2(uint32_t p, uint32_t k)
	{
		assert(k < 6);
		switch (k >> 1)
		{
		case 0:
			if (p <= 1)
				p = 0;
			else
				p = 1;
			break;
		case 1:
			if (p == 0)
				p = 0;
			else
				p = 1;
			break;
		case 2:
			if ((p == 0) || (p == 2))
				p = 0;
			else
				p = 1;
			break;
		}
		if (k & 1)
			p = 1 - p;
		return p;
	}

	static const uint8_t g_zero_pattern[16] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

	const uint8_t g_astc_bc7_patterns2[TOTAL_ASTC_BC7_COMMON_PARTITIONS2][16] =
	{
		{ 0,0,1,1,0,0,1,1,0,0,1,1,0,0,1,1 }, { 0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1 }, { 1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0 }, { 0,0,0,1,0,0,1,1,0,0,1,1,0,1,1,1 },
		{ 1,1,1,1,1,1,1,0,1,1,1,0,1,1,0,0 }, { 0,0,1,1,0,1,1,1,0,1,1,1,1,1,1,1 }, { 1,1,1,0,1,1,0,0,1,0,0,0,0,0,0,0 }, { 1,1,1,1,1,1,1,0,1,1,0,0,1,0,0,0 },
		{ 0,0,0,0,0,0,0,0,0,0,0,1,0,0,1,1 }, { 1,1,0,0,1,0,0,0,0,0,0,0,0,0,0,0 }, { 0,0,0,0,0,0,0,1,0,1,1,1,1,1,1,1 }, { 1,1,1,1,1,1,1,1,1,1,1,0,1,0,0,0 },
		{ 1,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0 }, { 1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0 }, { 0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1 }, { 1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0 },
		{ 1,0,0,0,1,1,1,0,1,1,1,1,1,1,1,1 }, { 1,1,1,1,1,1,1,1,0,1,1,1,0,0,0,1 }, { 0,1,1,1,0,0,1,1,0,0,0,1,0,0,0,0 }, { 0,0,1,1,0,0,0,1,0,0,0,0,0,0,0,0 },
		{ 0,0,0,0,1,0,0,0,1,1,0,0,1,1,1,0 }, { 1,1,1,1,1,1,1,1,0,1,1,1,0,0,1,1 }, { 1,0,0,0,1,1,0,0,1,1,0,0,1,1,1,0 }, { 0,0,1,1,0,0,0,1,0,0,0,1,0,0,0,0 },
		{ 1,1,1,1,0,1,1,1,0,1,1,1,0,0,1,1 }, { 0,1,1,0,0,1,1,0,0,1,1,0,0,1,1,0 }, { 1,1,1,1,0,0,0,0,0,0,0,0,1,1,1,1 }, { 1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0 },
		{ 1,1,1,1,0,0,0,0,1,1,1,1,0,0,0,0 }, { 1,0,0,1,0,0,1,1,0,1,1,0,1,1,0,0 }
	};

	const uint8_t g_astc_bc7_patterns3[TOTAL_ASTC_BC7_COMMON_PARTITIONS3][16] =
	{
		{ 0,0,0,0,0,0,0,0,1,1,2,2,1,1,2,2 }, { 1,1,1,1,1,1,1,1,0,0,0,0,2,2,2,2 }, { 1,1,1,1,0,0,0,0,0,0,0,0,2,2,2,2 },	{ 1,1,1,1,2,2,2,2,0,0,0,0,0,0,0,0 },
		{ 1,1,2,0,1,1,2,0,1,1,2,0,1,1,2,0 }, { 0,1,1,2,0,1,1,2,0,1,1,2,0,1,1,2 }, { 0,2,1,1,0,2,1,1,0,2,1,1,0,2,1,1 },	{ 2,0,0,0,2,0,0,0,2,1,1,1,2,1,1,1 },
		{ 2,0,1,2,2,0,1,2,2,0,1,2,2,0,1,2 }, { 1,1,1,1,0,0,0,0,2,2,2,2,1,1,1,1 }, { 0,0,2,2,0,0,1,1,0,0,1,1,0,0,2,2 }
	};

	const uint8_t g_bc7_3_astc2_patterns2[TOTAL_BC7_3_ASTC2_COMMON_PARTITIONS][16] =
	{
		{ 0,0,0,0,1,1,1,1,0,0,0,0,0,0,0,0 }, { 0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0 }, { 1,1,0,0,1,1,0,0,1,0,0,0,0,0,0,0 },	{ 0,0,0,0,0,0,0,1,0,0,1,1,0,0,1,1 },
		{ 1,1,1,1,1,1,1,1,0,0,0,0,1,1,1,1 }, { 0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0 }, { 0,0,0,1,0,0,1,1,1,1,1,1,1,1,1,1 },	{ 0,1,1,1,0,0,1,1,0,0,1,1,0,0,1,1 },
		{ 1,1,0,0,0,0,0,0,0,0,1,1,1,1,0,0 }, { 0,1,1,1,0,1,1,1,0,0,0,0,0,0,0,0 }, { 0,0,0,0,0,0,0,0,1,1,1,0,1,1,1,0 },	{ 1,1,0,0,0,0,0,0,0,0,0,0,1,1,0,0 },
		{ 0,1,1,1,0,0,1,1,0,0,0,0,0,0,0,0 }, { 0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1 }, { 1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,0 },	{ 1,1,0,0,1,1,0,0,1,1,0,0,1,0,0,0 },
		{ 1,1,1,1,1,1,1,1,1,0,0,0,1,0,0,0 }, { 0,0,1,1,0,1,1,0,1,1,0,0,1,0,0,0 }, { 1,1,1,1,0,1,1,1,0,0,0,0,0,0,0,0 }
	};

	const uint8_t g_astc_bc7_pattern2_anchors[TOTAL_ASTC_BC7_COMMON_PARTITIONS2][3] =
	{
		{ 0, 2 }, { 0, 3 }, { 1, 0 }, { 0, 3 }, { 7, 0 }, { 0, 2 }, { 3, 0 }, { 7, 0 },
		{ 0, 11 }, { 2, 0 }, { 0, 7 }, { 11, 0 }, { 3, 0 }, { 8, 0 }, { 0, 4 }, { 12, 0 },
		{ 1, 0 }, { 8, 0 }, { 0, 1 }, { 0, 2 }, { 0, 4 }, { 8, 0 }, { 1, 0 }, { 0, 2 },
		{ 4, 0 }, { 0, 1 }, { 4, 0 }, { 1, 0 }, { 4, 0 }, { 1, 0 }
	};

	const uint8_t g_astc_bc7_pattern3_anchors[TOTAL_ASTC_BC7_COMMON_PARTITIONS3][3] =
	{
		{ 0, 8, 10 },	{ 8, 0, 12 }, { 4, 0, 12 }, { 8, 0, 4 }, { 3, 0, 2 }, { 0, 1, 3 }, { 0, 2, 1 }, { 1, 9, 0 }, { 1, 2, 0 }, { 4, 0, 8 }, { 0, 6, 2 }
	};

	const uint8_t g_bc7_3_astc2_patterns2_anchors[TOTAL_BC7_3_ASTC2_COMMON_PARTITIONS][3] =
	{
		{ 0, 4 }, { 0, 2 }, { 2, 0 }, { 0, 7 }, { 8, 0 }, { 0, 1 }, { 0, 3 }, { 0, 1 }, { 2, 0 }, { 0, 1 }, { 0, 8 }, { 2, 0 }, { 0, 1 }, { 0, 7 }, { 12, 0 }, { 2, 0 }, { 9, 0 }, { 0, 2 }, { 4, 0 }
	};

	const uint32_t g_uastc_mode_huff_codes[TOTAL_UASTC_MODES + 1][2] =
	{
		{ 0x1, 4 },
		{ 0x35, 6 },
		{ 0x1D, 5 },
		{ 0x3, 5 },

		{ 0x13, 5 },
		{ 0xB, 5 },
		{ 0x1B, 5 },
		{ 0x7, 5 },

		{ 0x17, 5 },
		{ 0xF, 5 },
		{ 0x2, 3 },
		{ 0x0, 2 },

		{ 0x6, 3 },
		{ 0x1F, 5 },
		{ 0xD, 5 },
		{ 0x5, 7 },

		{ 0x15, 6 },
		{ 0x25, 6 },
		{ 0x9, 4 },
		{ 0x45, 7 } // future expansion
	};

	// If g_uastc_mode_huff_codes[] changes this table must be updated!
	static const uint8_t g_uastc_huff_modes[128] =
	{
		11,0,10,3,11,15,12,7,11,18,10,5,11,14,12,9,11,0,10,4,11,16,12,8,11,18,10,6,11,2,12,13,11,0,10,3,11,17,12,7,11,18,10,5,11,14,12,9,11,0,10,4,11,1,12,8,11,18,10,6,11,2,12,13,11,0,10,3,11,
		19,12,7,11,18,10,5,11,14,12,9,11,0,10,4,11,16,12,8,11,18,10,6,11,2,12,13,11,0,10,3,11,17,12,7,11,18,10,5,11,14,12,9,11,0,10,4,11,1,12,8,11,18,10,6,11,2,12,13
	};

	const uint8_t g_uastc_mode_weight_bits[TOTAL_UASTC_MODES] = { 4, 2, 3, 2, 2, 3, 2, 2,			0,  2, 4, 2, 3, 1, 2,			4, 2, 2,     5 };
	const uint8_t g_uastc_mode_weight_ranges[TOTAL_UASTC_MODES] = { 8, 2, 5, 2, 2, 5, 2, 2,			0,  2, 8, 2, 5, 0, 2,			8, 2, 2,     11 };
	const uint8_t g_uastc_mode_endpoint_ranges[TOTAL_UASTC_MODES] = { 19, 20, 8, 7, 12, 20, 18, 12,	0,  8, 13, 13, 19, 20, 20,		20, 20, 20,  11 };
	const uint8_t g_uastc_mode_subsets[TOTAL_UASTC_MODES] = { 1, 1, 2, 3, 2, 1, 1, 2,			0,  2, 1, 1, 1, 1, 1,			1, 2, 1,     1 };
	const uint8_t g_uastc_mode_planes[TOTAL_UASTC_MODES] = { 1, 1, 1, 1, 1, 1, 2, 1,			0,  1, 1, 2, 1, 2, 1,			1, 1, 2,     1 };
	const uint8_t g_uastc_mode_comps[TOTAL_UASTC_MODES] = { 3, 3, 3, 3, 3, 3, 3, 3,			4,  4, 4, 4, 4, 4, 4,			2, 2, 2,     3 };
	const uint8_t g_uastc_mode_has_etc1_bias[TOTAL_UASTC_MODES] = { 1, 1, 1, 1, 1, 1, 1, 1,			0,  1, 0, 0, 0, 1, 1,			1, 1, 1,     1 };
	const uint8_t g_uastc_mode_has_bc1_hint0[TOTAL_UASTC_MODES] = { 1, 1, 1, 1, 1, 1, 1, 1,			0,  1, 1, 1, 1, 1, 1,			1, 1, 1,     1 };
	const uint8_t g_uastc_mode_has_bc1_hint1[TOTAL_UASTC_MODES] = { 1, 1, 1, 1, 1, 1, 1, 1,			0,  1, 0, 0, 0, 1, 1,			1, 1, 1,     1 };
	const uint8_t g_uastc_mode_cem[TOTAL_UASTC_MODES] = { 8, 8, 8, 8, 8, 8, 8, 8,         0,  12, 12, 12, 12, 12, 12,   4, 4, 4,     8 };
	const uint8_t g_uastc_mode_has_alpha[TOTAL_UASTC_MODES] = { 0, 0, 0, 0, 0, 0, 0, 0,			1,  1, 1, 1, 1, 1, 1,			1, 1, 1,     0 };
	const uint8_t g_uastc_mode_is_la[TOTAL_UASTC_MODES] = { 0, 0, 0, 0, 0, 0, 0, 0,			0,  0, 0, 0, 0, 0, 0,			1, 1, 1,     0 };
	const uint8_t g_uastc_mode_total_hint_bits[TOTAL_UASTC_MODES] = { 15, 15, 15, 15, 15, 15, 15, 15, 0, 23, 17, 17, 17, 23, 23, 23, 23, 23, 15 };

	// bits, trits, quints
	const int g_astc_bise_range_table[TOTAL_ASTC_RANGES][3] =
	{
		{ 1, 0, 0 }, // 0-1 0
		{ 0, 1, 0 }, // 0-2 1
		{ 2, 0, 0 }, // 0-3 2
		{ 0, 0, 1 }, // 0-4 3

		{ 1, 1, 0 }, // 0-5 4
		{ 3, 0, 0 }, // 0-7 5
		{ 1, 0, 1 }, // 0-9 6
		{ 2, 1, 0 }, // 0-11 7

		{ 4, 0, 0 }, // 0-15 8
		{ 2, 0, 1 }, // 0-19 9
		{ 3, 1, 0 }, // 0-23 10
		{ 5, 0, 0 }, // 0-31 11

		{ 3, 0, 1 }, // 0-39 12
		{ 4, 1, 0 }, // 0-47 13
		{ 6, 0, 0 }, // 0-63 14
		{ 4, 0, 1 }, // 0-79 15

		{ 5, 1, 0 }, // 0-95 16
		{ 7, 0, 0 }, // 0-127 17
		{ 5, 0, 1 }, // 0-159 18
		{ 6, 1, 0 }, // 0-191 19

		{ 8, 0, 0 }, // 0-255 20
	};

	int astc_get_levels(int range)
	{
		assert(range < (int)BC7ENC_TOTAL_ASTC_RANGES);
		return (1 + 2 * g_astc_bise_range_table[range][1] + 4 * g_astc_bise_range_table[range][2]) << g_astc_bise_range_table[range][0];
	}

	// g_astc_unquant[] is the inverse of g_astc_sorted_order_unquant[]
	astc_quant_bin g_astc_unquant[BC7ENC_TOTAL_ASTC_RANGES][256]; // [ASTC encoded endpoint index]

	// Taken right from the ASTC spec.
	static struct
	{
		const char* m_pB_str;
		uint32_t m_c;
	} g_astc_endpoint_unquant_params[BC7ENC_TOTAL_ASTC_RANGES] =
	{
		{ "", 0 },
		{ "", 0 },
		{ "", 0 },
		{ "", 0 },
		{ "000000000", 204, },  // 0-5
		{ "", 0 },
		{ "000000000", 113, },  // 0-9
		{ "b000b0bb0", 93 },    // 0-11
		{ "", 0 },
		{ "b0000bb00", 54 },    // 0-19
		{ "cb000cbcb", 44 },   // 0-23
		{ "", 0 },
		{ "cb0000cbc", 26 },   // 0-39
		{ "dcb000dcb", 22 },   // 0-47
		{ "", 0 },
		{ "dcb0000dc", 13 },   // 0-79
		{ "edcb000ed", 11 },   // 0-95
		{ "", 0 },
		{ "edcb0000e", 6 },    // 0-159
		{ "fedcb000f", 5 },     // 0-191
		{ "", 0 },
	};

	bool astc_is_valid_endpoint_range(uint32_t range)
	{
		if ((g_astc_bise_range_table[range][1] == 0) && (g_astc_bise_range_table[range][2] == 0))
			return true;

		return g_astc_endpoint_unquant_params[range].m_c != 0;
	}

	uint32_t unquant_astc_endpoint(uint32_t packed_bits, uint32_t packed_trits, uint32_t packed_quints, uint32_t range)
	{
		assert(range < BC7ENC_TOTAL_ASTC_RANGES);

		const uint32_t bits = g_astc_bise_range_table[range][0];
		const uint32_t trits = g_astc_bise_range_table[range][1];
		const uint32_t quints = g_astc_bise_range_table[range][2];

		uint32_t val = 0;
		if ((!trits) && (!quints))
		{
			assert(!packed_trits && !packed_quints);

			int bits_left = 8;
			while (bits_left > 0)
			{
				uint32_t v = packed_bits;

				int n = basisu::minimumi(bits_left, bits);
				if (n < (int)bits)
					v >>= (bits - n);

				assert(v < (1U << n));

				val |= (v << (bits_left - n));
				bits_left -= n;
			}
		}
		else
		{
			const uint32_t A = (packed_bits & 1) ? 511 : 0;
			const uint32_t C = g_astc_endpoint_unquant_params[range].m_c;
			const uint32_t D = trits ? packed_trits : packed_quints;

			assert(C);

			uint32_t B = 0;
			for (uint32_t i = 0; i < 9; i++)
			{
				B <<= 1;

				char c = g_astc_endpoint_unquant_params[range].m_pB_str[i];
				if (c != '0')
				{
					c -= 'a';
					B |= ((packed_bits >> c) & 1);
				}
			}

			val = D * C + B;
			val = val ^ A;
			val = (A & 0x80) | (val >> 2);
		}

		return val;
	}

	uint32_t unquant_astc_endpoint_val(uint32_t packed_val, uint32_t range)
	{
		assert(range < BC7ENC_TOTAL_ASTC_RANGES);
		assert(packed_val < (uint32_t)astc_get_levels(range));

		const uint32_t bits = g_astc_bise_range_table[range][0];
		const uint32_t trits = g_astc_bise_range_table[range][1];
		const uint32_t quints = g_astc_bise_range_table[range][2];

		if ((!trits) && (!quints))
			return unquant_astc_endpoint(packed_val, 0, 0, range);
		else if (trits)
			return unquant_astc_endpoint(packed_val & ((1 << bits) - 1), packed_val >> bits, 0, range);
		else
			return unquant_astc_endpoint(packed_val & ((1 << bits) - 1), 0, packed_val >> bits, range);
	}

	// BC7 - Various BC7 tables/helpers
	const uint32_t g_bc7_weights1[2] = { 0, 64 };
	const uint32_t g_bc7_weights2[4] = { 0, 21, 43, 64 };
	const uint32_t g_bc7_weights3[8] = { 0, 9, 18, 27, 37, 46, 55, 64 };
	const uint32_t g_bc7_weights4[16] = { 0, 4, 9, 13, 17, 21, 26, 30, 34, 38, 43, 47, 51, 55, 60, 64 };
	const uint32_t g_astc_weights4[16] = { 0, 4, 8, 12, 17, 21, 25, 29, 35, 39, 43, 47, 52, 56, 60, 64 };
	const uint32_t g_astc_weights5[32] = { 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64 };
	const uint32_t g_astc_weights_3levels[3] = { 0, 32, 64 };

	const uint8_t g_bc7_partition1[16] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 };

	const uint8_t g_bc7_partition2[64 * 16] =
	{
		0,0,1,1,0,0,1,1,0,0,1,1,0,0,1,1,		0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,		0,1,1,1,0,1,1,1,0,1,1,1,0,1,1,1,		0,0,0,1,0,0,1,1,0,0,1,1,0,1,1,1,		0,0,0,0,0,0,0,1,0,0,0,1,0,0,1,1,		0,0,1,1,0,1,1,1,0,1,1,1,1,1,1,1,		0,0,0,1,0,0,1,1,0,1,1,1,1,1,1,1,		0,0,0,0,0,0,0,1,0,0,1,1,0,1,1,1,
		0,0,0,0,0,0,0,0,0,0,0,1,0,0,1,1,		0,0,1,1,0,1,1,1,1,1,1,1,1,1,1,1,		0,0,0,0,0,0,0,1,0,1,1,1,1,1,1,1,		0,0,0,0,0,0,0,0,0,0,0,1,0,1,1,1,		0,0,0,1,0,1,1,1,1,1,1,1,1,1,1,1,		0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,		0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,		0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,
		0,0,0,0,1,0,0,0,1,1,1,0,1,1,1,1,		0,1,1,1,0,0,0,1,0,0,0,0,0,0,0,0,		0,0,0,0,0,0,0,0,1,0,0,0,1,1,1,0,		0,1,1,1,0,0,1,1,0,0,0,1,0,0,0,0,		0,0,1,1,0,0,0,1,0,0,0,0,0,0,0,0,		0,0,0,0,1,0,0,0,1,1,0,0,1,1,1,0,		0,0,0,0,0,0,0,0,1,0,0,0,1,1,0,0,		0,1,1,1,0,0,1,1,0,0,1,1,0,0,0,1,
		0,0,1,1,0,0,0,1,0,0,0,1,0,0,0,0,		0,0,0,0,1,0,0,0,1,0,0,0,1,1,0,0,		0,1,1,0,0,1,1,0,0,1,1,0,0,1,1,0,		0,0,1,1,0,1,1,0,0,1,1,0,1,1,0,0,		0,0,0,1,0,1,1,1,1,1,1,0,1,0,0,0,		0,0,0,0,1,1,1,1,1,1,1,1,0,0,0,0,		0,1,1,1,0,0,0,1,1,0,0,0,1,1,1,0,		0,0,1,1,1,0,0,1,1,0,0,1,1,1,0,0,
		0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,		0,0,0,0,1,1,1,1,0,0,0,0,1,1,1,1,		0,1,0,1,1,0,1,0,0,1,0,1,1,0,1,0,		0,0,1,1,0,0,1,1,1,1,0,0,1,1,0,0,		0,0,1,1,1,1,0,0,0,0,1,1,1,1,0,0,		0,1,0,1,0,1,0,1,1,0,1,0,1,0,1,0,		0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,		0,1,0,1,1,0,1,0,1,0,1,0,0,1,0,1,
		0,1,1,1,0,0,1,1,1,1,0,0,1,1,1,0,		0,0,0,1,0,0,1,1,1,1,0,0,1,0,0,0,		0,0,1,1,0,0,1,0,0,1,0,0,1,1,0,0,		0,0,1,1,1,0,1,1,1,1,0,1,1,1,0,0,		0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,		0,0,1,1,1,1,0,0,1,1,0,0,0,0,1,1,		0,1,1,0,0,1,1,0,1,0,0,1,1,0,0,1,		0,0,0,0,0,1,1,0,0,1,1,0,0,0,0,0,
		0,1,0,0,1,1,1,0,0,1,0,0,0,0,0,0,		0,0,1,0,0,1,1,1,0,0,1,0,0,0,0,0,		0,0,0,0,0,0,1,0,0,1,1,1,0,0,1,0,		0,0,0,0,0,1,0,0,1,1,1,0,0,1,0,0,		0,1,1,0,1,1,0,0,1,0,0,1,0,0,1,1,		0,0,1,1,0,1,1,0,1,1,0,0,1,0,0,1,		0,1,1,0,0,0,1,1,1,0,0,1,1,1,0,0,		0,0,1,1,1,0,0,1,1,1,0,0,0,1,1,0,
		0,1,1,0,1,1,0,0,1,1,0,0,1,0,0,1,		0,1,1,0,0,0,1,1,0,0,1,1,1,0,0,1,		0,1,1,1,1,1,1,0,1,0,0,0,0,0,0,1,		0,0,0,1,1,0,0,0,1,1,1,0,0,1,1,1,		0,0,0,0,1,1,1,1,0,0,1,1,0,0,1,1,		0,0,1,1,0,0,1,1,1,1,1,1,0,0,0,0,		0,0,1,0,0,0,1,0,1,1,1,0,1,1,1,0,		0,1,0,0,0,1,0,0,0,1,1,1,0,1,1,1
	};

	const uint8_t g_bc7_partition3[64 * 16] =
	{
		0,0,1,1,0,0,1,1,0,2,2,1,2,2,2,2,		0,0,0,1,0,0,1,1,2,2,1,1,2,2,2,1,		0,0,0,0,2,0,0,1,2,2,1,1,2,2,1,1,		0,2,2,2,0,0,2,2,0,0,1,1,0,1,1,1,		0,0,0,0,0,0,0,0,1,1,2,2,1,1,2,2,		0,0,1,1,0,0,1,1,0,0,2,2,0,0,2,2,		0,0,2,2,0,0,2,2,1,1,1,1,1,1,1,1,		0,0,1,1,0,0,1,1,2,2,1,1,2,2,1,1,
		0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,		0,0,0,0,1,1,1,1,1,1,1,1,2,2,2,2,		0,0,0,0,1,1,1,1,2,2,2,2,2,2,2,2,		0,0,1,2,0,0,1,2,0,0,1,2,0,0,1,2,		0,1,1,2,0,1,1,2,0,1,1,2,0,1,1,2,		0,1,2,2,0,1,2,2,0,1,2,2,0,1,2,2,		0,0,1,1,0,1,1,2,1,1,2,2,1,2,2,2,		0,0,1,1,2,0,0,1,2,2,0,0,2,2,2,0,
		0,0,0,1,0,0,1,1,0,1,1,2,1,1,2,2,		0,1,1,1,0,0,1,1,2,0,0,1,2,2,0,0,		0,0,0,0,1,1,2,2,1,1,2,2,1,1,2,2,		0,0,2,2,0,0,2,2,0,0,2,2,1,1,1,1,		0,1,1,1,0,1,1,1,0,2,2,2,0,2,2,2,		0,0,0,1,0,0,0,1,2,2,2,1,2,2,2,1,		0,0,0,0,0,0,1,1,0,1,2,2,0,1,2,2,		0,0,0,0,1,1,0,0,2,2,1,0,2,2,1,0,
		0,1,2,2,0,1,2,2,0,0,1,1,0,0,0,0,		0,0,1,2,0,0,1,2,1,1,2,2,2,2,2,2,		0,1,1,0,1,2,2,1,1,2,2,1,0,1,1,0,		0,0,0,0,0,1,1,0,1,2,2,1,1,2,2,1,		0,0,2,2,1,1,0,2,1,1,0,2,0,0,2,2,		0,1,1,0,0,1,1,0,2,0,0,2,2,2,2,2,		0,0,1,1,0,1,2,2,0,1,2,2,0,0,1,1,		0,0,0,0,2,0,0,0,2,2,1,1,2,2,2,1,
		0,0,0,0,0,0,0,2,1,1,2,2,1,2,2,2,		0,2,2,2,0,0,2,2,0,0,1,2,0,0,1,1,		0,0,1,1,0,0,1,2,0,0,2,2,0,2,2,2,		0,1,2,0,0,1,2,0,0,1,2,0,0,1,2,0,		0,0,0,0,1,1,1,1,2,2,2,2,0,0,0,0,		0,1,2,0,1,2,0,1,2,0,1,2,0,1,2,0,		0,1,2,0,2,0,1,2,1,2,0,1,0,1,2,0,		0,0,1,1,2,2,0,0,1,1,2,2,0,0,1,1,
		0,0,1,1,1,1,2,2,2,2,0,0,0,0,1,1,		0,1,0,1,0,1,0,1,2,2,2,2,2,2,2,2,		0,0,0,0,0,0,0,0,2,1,2,1,2,1,2,1,		0,0,2,2,1,1,2,2,0,0,2,2,1,1,2,2,		0,0,2,2,0,0,1,1,0,0,2,2,0,0,1,1,		0,2,2,0,1,2,2,1,0,2,2,0,1,2,2,1,		0,1,0,1,2,2,2,2,2,2,2,2,0,1,0,1,		0,0,0,0,2,1,2,1,2,1,2,1,2,1,2,1,
		0,1,0,1,0,1,0,1,0,1,0,1,2,2,2,2,		0,2,2,2,0,1,1,1,0,2,2,2,0,1,1,1,		0,0,0,2,1,1,1,2,0,0,0,2,1,1,1,2,		0,0,0,0,2,1,1,2,2,1,1,2,2,1,1,2,		0,2,2,2,0,1,1,1,0,1,1,1,0,2,2,2,		0,0,0,2,1,1,1,2,1,1,1,2,0,0,0,2,		0,1,1,0,0,1,1,0,0,1,1,0,2,2,2,2,		0,0,0,0,0,0,0,0,2,1,1,2,2,1,1,2,
		0,1,1,0,0,1,1,0,2,2,2,2,2,2,2,2,		0,0,2,2,0,0,1,1,0,0,1,1,0,0,2,2,		0,0,2,2,1,1,2,2,1,1,2,2,0,0,2,2,		0,0,0,0,0,0,0,0,0,0,0,0,2,1,1,2,		0,0,0,2,0,0,0,1,0,0,0,2,0,0,0,1,		0,2,2,2,1,2,2,2,0,2,2,2,1,2,2,2,		0,1,0,1,2,2,2,2,2,2,2,2,2,2,2,2,		0,1,1,1,2,0,1,1,2,2,0,1,2,2,2,0,
	};

	const uint8_t g_bc7_table_anchor_index_second_subset[64] = { 15,15,15,15,15,15,15,15,		15,15,15,15,15,15,15,15,		15, 2, 8, 2, 2, 8, 8,15,		2, 8, 2, 2, 8, 8, 2, 2,		15,15, 6, 8, 2, 8,15,15,		2, 8, 2, 2, 2,15,15, 6,		6, 2, 6, 8,15,15, 2, 2,		15,15,15,15,15, 2, 2,15 };

	const uint8_t g_bc7_table_anchor_index_third_subset_1[64] =
	{
		3, 3,15,15, 8, 3,15,15,		8, 8, 6, 6, 6, 5, 3, 3,		3, 3, 8,15, 3, 3, 6,10,		5, 8, 8, 6, 8, 5,15,15,		8,15, 3, 5, 6,10, 8,15,		15, 3,15, 5,15,15,15,15,		3,15, 5, 5, 5, 8, 5,10,		5,10, 8,13,15,12, 3, 3
	};

	const uint8_t g_bc7_table_anchor_index_third_subset_2[64] =
	{
		15, 8, 8, 3,15,15, 3, 8,		15,15,15,15,15,15,15, 8,		15, 8,15, 3,15, 8,15, 8,		3,15, 6,10,15,15,10, 8,		15, 3,15,10,10, 8, 9,10,		6,15, 8,15, 3, 6, 6, 8,		15, 3,15,15,15,15,15,15,		15,15,15,15, 3,15,15, 8
	};

	const uint8_t g_bc7_num_subsets[8] = { 3, 2, 3, 2, 1, 1, 1, 2 };
	const uint8_t g_bc7_partition_bits[8] = { 4, 6, 6, 6, 0, 0, 0, 6 };
	const uint8_t g_bc7_color_index_bitcount[8] = { 3, 3, 2, 2, 2, 2, 4, 2 };

	const uint8_t g_bc7_mode_has_p_bits[8] = { 1, 1, 0, 1, 0, 0, 1, 1 };
	const uint8_t g_bc7_mode_has_shared_p_bits[8] = { 0, 1, 0, 0, 0, 0, 0, 0 };
	const uint8_t g_bc7_color_precision_table[8] = { 4, 6, 5, 7, 5, 7, 7, 5 };
	const int8_t g_bc7_alpha_precision_table[8] = { 0, 0, 0, 0, 6, 8, 7, 5 };

	const uint8_t g_bc7_alpha_index_bitcount[8] = { 0, 0, 0, 0, 3, 2, 4, 2 };

	endpoint_err g_bc7_mode_6_optimal_endpoints[256][2]; // [c][pbit]
	endpoint_err g_bc7_mode_5_optimal_endpoints[256]; // [c]

	static inline void bc7_set_block_bits(uint8_t* pBytes, uint32_t val, uint32_t num_bits, uint32_t* pCur_ofs)
	{
		assert((num_bits <= 32) && (val < (1ULL << num_bits)));
		while (num_bits)
		{
			const uint32_t n = basisu::minimumu(8 - (*pCur_ofs & 7), num_bits);
			pBytes[*pCur_ofs >> 3] |= (uint8_t)(val << (*pCur_ofs & 7));
			val >>= n;
			num_bits -= n;
			*pCur_ofs += n;
		}
		assert(*pCur_ofs <= 128);
	}

	// TODO: Optimize this.
	void encode_bc7_block(void* pBlock, const bc7_optimization_results* pResults)
	{
		const uint32_t best_mode = pResults->m_mode;

		const uint32_t total_subsets = g_bc7_num_subsets[best_mode];
		const uint32_t total_partitions = 1 << g_bc7_partition_bits[best_mode];
		//const uint32_t num_rotations = 1 << g_bc7_rotation_bits[best_mode];
		//const uint32_t num_index_selectors = (best_mode == 4) ? 2 : 1;

		const uint8_t* pPartition;
		if (total_subsets == 1)
			pPartition = &g_bc7_partition1[0];
		else if (total_subsets == 2)
			pPartition = &g_bc7_partition2[pResults->m_partition * 16];
		else
			pPartition = &g_bc7_partition3[pResults->m_partition * 16];

		uint8_t color_selectors[16];
		memcpy(color_selectors, pResults->m_selectors, 16);

		uint8_t alpha_selectors[16];
		memcpy(alpha_selectors, pResults->m_alpha_selectors, 16);

		color_quad_u8 low[3], high[3];
		memcpy(low, pResults->m_low, sizeof(low));
		memcpy(high, pResults->m_high, sizeof(high));

		uint32_t pbits[3][2];
		memcpy(pbits, pResults->m_pbits, sizeof(pbits));

		int anchor[3] = { -1, -1, -1 };

		for (uint32_t k = 0; k < total_subsets; k++)
		{
			uint32_t anchor_index = 0;
			if (k)
			{
				if ((total_subsets == 3) && (k == 1))
					anchor_index = g_bc7_table_anchor_index_third_subset_1[pResults->m_partition];
				else if ((total_subsets == 3) && (k == 2))
					anchor_index = g_bc7_table_anchor_index_third_subset_2[pResults->m_partition];
				else
					anchor_index = g_bc7_table_anchor_index_second_subset[pResults->m_partition];
			}

			anchor[k] = anchor_index;

			const uint32_t color_index_bits = get_bc7_color_index_size(best_mode, pResults->m_index_selector);
			const uint32_t num_color_indices = 1 << color_index_bits;

			if (color_selectors[anchor_index] & (num_color_indices >> 1))
			{
				for (uint32_t i = 0; i < 16; i++)
					if (pPartition[i] == k)
						color_selectors[i] = (uint8_t)((num_color_indices - 1) - color_selectors[i]);

				if (get_bc7_mode_has_seperate_alpha_selectors(best_mode))
				{
					for (uint32_t q = 0; q < 3; q++)
					{
						uint8_t t = low[k].m_c[q];
						low[k].m_c[q] = high[k].m_c[q];
						high[k].m_c[q] = t;
					}
				}
				else
				{
					color_quad_u8 tmp = low[k];
					low[k] = high[k];
					high[k] = tmp;
				}

				if (!g_bc7_mode_has_shared_p_bits[best_mode])
				{
					uint32_t t = pbits[k][0];
					pbits[k][0] = pbits[k][1];
					pbits[k][1] = t;
				}
			}

			if (get_bc7_mode_has_seperate_alpha_selectors(best_mode))
			{
				const uint32_t alpha_index_bits = get_bc7_alpha_index_size(best_mode, pResults->m_index_selector);
				const uint32_t num_alpha_indices = 1 << alpha_index_bits;

				if (alpha_selectors[anchor_index] & (num_alpha_indices >> 1))
				{
					for (uint32_t i = 0; i < 16; i++)
						if (pPartition[i] == k)
							alpha_selectors[i] = (uint8_t)((num_alpha_indices - 1) - alpha_selectors[i]);

					uint8_t t = low[k].m_c[3];
					low[k].m_c[3] = high[k].m_c[3];
					high[k].m_c[3] = t;
				}
			}
		}

		uint8_t* pBlock_bytes = (uint8_t*)(pBlock);
		memset(pBlock_bytes, 0, BC7ENC_BLOCK_SIZE);

		uint32_t cur_bit_ofs = 0;
		bc7_set_block_bits(pBlock_bytes, 1 << best_mode, best_mode + 1, &cur_bit_ofs);

		if ((best_mode == 4) || (best_mode == 5))
			bc7_set_block_bits(pBlock_bytes, pResults->m_rotation, 2, &cur_bit_ofs);

		if (best_mode == 4)
			bc7_set_block_bits(pBlock_bytes, pResults->m_index_selector, 1, &cur_bit_ofs);

		if (total_partitions > 1)
			bc7_set_block_bits(pBlock_bytes, pResults->m_partition, (total_partitions == 64) ? 6 : 4, &cur_bit_ofs);

		const uint32_t total_comps = (best_mode >= 4) ? 4 : 3;
		for (uint32_t comp = 0; comp < total_comps; comp++)
		{
			for (uint32_t subset = 0; subset < total_subsets; subset++)
			{
				bc7_set_block_bits(pBlock_bytes, low[subset].m_c[comp], (comp == 3) ? g_bc7_alpha_precision_table[best_mode] : g_bc7_color_precision_table[best_mode], &cur_bit_ofs);
				bc7_set_block_bits(pBlock_bytes, high[subset].m_c[comp], (comp == 3) ? g_bc7_alpha_precision_table[best_mode] : g_bc7_color_precision_table[best_mode], &cur_bit_ofs);
			}
		}

		if (g_bc7_mode_has_p_bits[best_mode])
		{
			for (uint32_t subset = 0; subset < total_subsets; subset++)
			{
				bc7_set_block_bits(pBlock_bytes, pbits[subset][0], 1, &cur_bit_ofs);
				if (!g_bc7_mode_has_shared_p_bits[best_mode])
					bc7_set_block_bits(pBlock_bytes, pbits[subset][1], 1, &cur_bit_ofs);
			}
		}

		for (uint32_t y = 0; y < 4; y++)
		{
			for (uint32_t x = 0; x < 4; x++)
			{
				int idx = x + y * 4;

				uint32_t n = pResults->m_index_selector ? get_bc7_alpha_index_size(best_mode, pResults->m_index_selector) : get_bc7_color_index_size(best_mode, pResults->m_index_selector);

				if ((idx == anchor[0]) || (idx == anchor[1]) || (idx == anchor[2]))
					n--;

				bc7_set_block_bits(pBlock_bytes, pResults->m_index_selector ? alpha_selectors[idx] : color_selectors[idx], n, &cur_bit_ofs);
			}
		}

		if (get_bc7_mode_has_seperate_alpha_selectors(best_mode))
		{
			for (uint32_t y = 0; y < 4; y++)
			{
				for (uint32_t x = 0; x < 4; x++)
				{
					int idx = x + y * 4;

					uint32_t n = pResults->m_index_selector ? get_bc7_color_index_size(best_mode, pResults->m_index_selector) : get_bc7_alpha_index_size(best_mode, pResults->m_index_selector);

					if ((idx == anchor[0]) || (idx == anchor[1]) || (idx == anchor[2]))
						n--;

					bc7_set_block_bits(pBlock_bytes, pResults->m_index_selector ? color_selectors[idx] : alpha_selectors[idx], n, &cur_bit_ofs);
				}
			}
		}

		assert(cur_bit_ofs == 128);
	}

	// ASTC
	static inline void astc_set_bits_1_to_9(uint32_t* pDst, int& bit_offset, uint32_t code, uint32_t codesize)
	{
		uint8_t* pBuf = reinterpret_cast<uint8_t*>(pDst);

		assert(codesize <= 9);
		if (codesize)
		{
			uint32_t byte_bit_offset = bit_offset & 7;
			uint32_t val = code << byte_bit_offset;

			uint32_t index = bit_offset >> 3;
			pBuf[index] |= (uint8_t)val;

			if (codesize > (8 - byte_bit_offset))
				pBuf[index + 1] |= (uint8_t)(val >> 8);

			bit_offset += codesize;
		}
	}

	void pack_astc_solid_block(void* pDst_block, const color32& color)
	{
		uint32_t r = color[0], g = color[1], b = color[2];
		uint32_t a = color[3];

		uint32_t* pOutput = static_cast<uint32_t*>(pDst_block);
		uint8_t* pBytes = reinterpret_cast<uint8_t*>(pDst_block);

		pBytes[0] = 0xfc; pBytes[1] = 0xfd; pBytes[2] = 0xff; pBytes[3] = 0xff;

		pOutput[1] = 0xffffffff;
		pOutput[2] = 0;
		pOutput[3] = 0;

		int bit_pos = 64;
		astc_set_bits(reinterpret_cast<uint32_t*>(pDst_block), bit_pos, r | (r << 8), 16);
		astc_set_bits(reinterpret_cast<uint32_t*>(pDst_block), bit_pos, g | (g << 8), 16);
		astc_set_bits(reinterpret_cast<uint32_t*>(pDst_block), bit_pos, b | (b << 8), 16);
		astc_set_bits(reinterpret_cast<uint32_t*>(pDst_block), bit_pos, a | (a << 8), 16);
	}

	// See 23.21 https://www.khronos.org/registry/DataFormat/specs/1.3/dataformat.1.3.inline.html#_partition_pattern_generation
#ifdef _DEBUG
	static inline uint32_t astc_hash52(uint32_t v)
	{
		uint32_t p = v;
		p ^= p >> 15;	p -= p << 17;	p += p << 7;	p += p << 4;
		p ^= p >> 5;	p += p << 16;	p ^= p >> 7;	p ^= p >> 3;
		p ^= p << 6;	p ^= p >> 17;
		return p;
	}

	int astc_compute_texel_partition(int seed, int x, int y, int z, int partitioncount, bool small_block)
	{
		if (small_block)
		{
			x <<= 1; y <<= 1; z <<= 1;
		}
		seed += (partitioncount - 1) * 1024;
		uint32_t rnum = astc_hash52(seed);
		uint8_t seed1 = rnum & 0xF;
		uint8_t seed2 = (rnum >> 4) & 0xF;
		uint8_t seed3 = (rnum >> 8) & 0xF;
		uint8_t seed4 = (rnum >> 12) & 0xF;
		uint8_t seed5 = (rnum >> 16) & 0xF;
		uint8_t seed6 = (rnum >> 20) & 0xF;
		uint8_t seed7 = (rnum >> 24) & 0xF;
		uint8_t seed8 = (rnum >> 28) & 0xF;
		uint8_t seed9 = (rnum >> 18) & 0xF;
		uint8_t seed10 = (rnum >> 22) & 0xF;
		uint8_t seed11 = (rnum >> 26) & 0xF;
		uint8_t seed12 = ((rnum >> 30) | (rnum << 2)) & 0xF;

		seed1 *= seed1;    seed2 *= seed2;
		seed3 *= seed3;    seed4 *= seed4;
		seed5 *= seed5;    seed6 *= seed6;
		seed7 *= seed7;    seed8 *= seed8;
		seed9 *= seed9;    seed10 *= seed10;
		seed11 *= seed11;   seed12 *= seed12;

		int sh1, sh2, sh3;
		if (seed & 1)
		{
			sh1 = (seed & 2 ? 4 : 5); sh2 = (partitioncount == 3 ? 6 : 5);
		}
		else
		{
			sh1 = (partitioncount == 3 ? 6 : 5); sh2 = (seed & 2 ? 4 : 5);
		}
		sh3 = (seed & 0x10) ? sh1 : sh2;

		seed1 >>= sh1; seed2 >>= sh2; seed3 >>= sh1; seed4 >>= sh2;
		seed5 >>= sh1; seed6 >>= sh2; seed7 >>= sh1; seed8 >>= sh2;
		seed9 >>= sh3; seed10 >>= sh3; seed11 >>= sh3; seed12 >>= sh3;

		int a = seed1 * x + seed2 * y + seed11 * z + (rnum >> 14);
		int b = seed3 * x + seed4 * y + seed12 * z + (rnum >> 10);
		int c = seed5 * x + seed6 * y + seed9 * z + (rnum >> 6);
		int d = seed7 * x + seed8 * y + seed10 * z + (rnum >> 2);

		a &= 0x3F; b &= 0x3F; c &= 0x3F; d &= 0x3F;

		if (partitioncount < 4) d = 0;
		if (partitioncount < 3) c = 0;

		if (a >= b && a >= c && a >= d)
			return 0;
		else if (b >= c && b >= d)
			return 1;
		else if (c >= d)
			return 2;
		else
			return 3;
	}
#endif

	static const uint8_t g_astc_quint_encode[125] =
	{
		0, 1, 2, 3, 4, 8, 9, 10, 11, 12, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28, 5, 13, 21, 29, 6, 32, 33, 34, 35, 36, 40, 41, 42, 43, 44, 48, 49, 50, 51, 52, 56, 57,
		58, 59, 60, 37, 45, 53, 61, 14, 64, 65, 66, 67, 68, 72, 73, 74, 75, 76, 80, 81, 82, 83, 84, 88, 89, 90, 91, 92, 69, 77, 85, 93, 22, 96, 97, 98, 99, 100, 104,
		105, 106, 107, 108, 112, 113, 114, 115, 116, 120, 121, 122, 123, 124, 101, 109, 117, 125, 30, 102, 103, 70, 71, 38, 110, 111, 78, 79, 46, 118, 119, 86, 87, 54,
		126, 127, 94, 95, 62, 39, 47, 55, 63, 31
	};

	// Encodes 3 values to output, usable for any range that uses quints and bits
	static inline void astc_encode_quints(uint32_t* pOutput, const uint8_t* pValues, int& bit_pos, int n)
	{
		// First extract the quints and the bits from the 3 input values
		int quints = 0, bits[3];
		const uint32_t bit_mask = (1 << n) - 1;
		for (int i = 0; i < 3; i++)
		{
			static const int s_muls[3] = { 1, 5, 25 };

			const int t = pValues[i] >> n;

			quints += t * s_muls[i];
			bits[i] = pValues[i] & bit_mask;
		}

		// Encode the quints, by inverting the bit manipulations done by the decoder, converting 3 quints into 7-bits.
		// See https://www.khronos.org/registry/DataFormat/specs/1.2/dataformat.1.2.html#astc-integer-sequence-encoding

		assert(quints < 125);
		const int T = g_astc_quint_encode[quints];

		// Now interleave the 7 encoded quint bits with the bits to form the encoded output. See table 95-96.
		astc_set_bits(pOutput, bit_pos, bits[0] | (astc_extract_bits(T, 0, 2) << n) | (bits[1] << (3 + n)) | (astc_extract_bits(T, 3, 4) << (3 + n * 2)) |
			(bits[2] << (5 + n * 2)) | (astc_extract_bits(T, 5, 6) << (5 + n * 3)), 7 + n * 3);
	}

	// Packs values using ASTC's BISE to output buffer.
	static void astc_pack_bise(uint32_t* pDst, const uint8_t* pSrc_vals, int bit_pos, int num_vals, int range)
	{
		uint32_t temp[5] = { 0, 0, 0, 0, 0 };

		const int num_bits = g_astc_bise_range_table[range][0];

		int group_size = 0;
		if (g_astc_bise_range_table[range][1])
			group_size = 5;
		else if (g_astc_bise_range_table[range][2])
			group_size = 3;

		if (group_size)
		{
			// Range has trits or quints - pack each group of 5 or 3 values 
			const int total_groups = (group_size == 5) ? ((num_vals + 4) / 5) : ((num_vals + 2) / 3);

			for (int group_index = 0; group_index < total_groups; group_index++)
			{
				uint8_t vals[5] = { 0, 0, 0, 0, 0 };

				const int limit = basisu::minimum(group_size, num_vals - group_index * group_size);
				for (int i = 0; i < limit; i++)
					vals[i] = pSrc_vals[group_index * group_size + i];

				if (group_size == 5)
					astc_encode_trits(temp, vals, bit_pos, num_bits);
				else
					astc_encode_quints(temp, vals, bit_pos, num_bits);
			}
		}
		else
		{
			for (int i = 0; i < num_vals; i++)
				astc_set_bits_1_to_9(temp, bit_pos, pSrc_vals[i], num_bits);
		}

		pDst[0] |= temp[0]; pDst[1] |= temp[1];
		pDst[2] |= temp[2]; pDst[3] |= temp[3];
	}

	const uint32_t ASTC_BLOCK_MODE_BITS = 11;
	const uint32_t ASTC_PART_BITS = 2;
	const uint32_t ASTC_CEM_BITS = 4;
	const uint32_t ASTC_PARTITION_INDEX_BITS = 10;
	const uint32_t ASTC_CCS_BITS = 2;

	const uint32_t g_uastc_mode_astc_block_mode[TOTAL_UASTC_MODES] = { 0x242, 0x42, 0x53, 0x42, 0x42, 0x53, 0x442, 0x42, 0, 0x42, 0x242, 0x442, 0x53, 0x441, 0x42, 0x242, 0x42, 0x442, 0x253 };

	bool pack_astc_block(uint32_t* pDst, const astc_block_desc* pBlock, uint32_t uastc_mode)
	{
		assert(uastc_mode < TOTAL_UASTC_MODES);
		uint8_t* pDst_bytes = reinterpret_cast<uint8_t*>(pDst);

		const int total_weights = pBlock->m_dual_plane ? 32 : 16;

		// Set mode bits - see Table 146-147
		uint32_t mode = g_uastc_mode_astc_block_mode[uastc_mode];
		pDst_bytes[0] = (uint8_t)mode;
		pDst_bytes[1] = (uint8_t)(mode >> 8);

		memset(pDst_bytes + 2, 0, 16 - 2);

		int bit_pos = ASTC_BLOCK_MODE_BITS;

		// We only support 1-5 bit weight indices
		assert(!g_astc_bise_range_table[pBlock->m_weight_range][1] && !g_astc_bise_range_table[pBlock->m_weight_range][2]);
		const int bits_per_weight = g_astc_bise_range_table[pBlock->m_weight_range][0];

		// See table 143 - PART
		astc_set_bits_1_to_9(pDst, bit_pos, pBlock->m_subsets - 1, ASTC_PART_BITS);

		if (pBlock->m_subsets == 1)
			astc_set_bits_1_to_9(pDst, bit_pos, pBlock->m_cem, ASTC_CEM_BITS);
		else
		{
			// See table 145
			astc_set_bits(pDst, bit_pos, pBlock->m_partition_seed, ASTC_PARTITION_INDEX_BITS);

			// Table 150 - we assume all CEM's are equal, so write 2 0's along with the CEM
			astc_set_bits_1_to_9(pDst, bit_pos, (pBlock->m_cem << 2) & 63, ASTC_CEM_BITS + 2);
		}

		if (pBlock->m_dual_plane)
		{
			const int total_weight_bits = total_weights * bits_per_weight;

			// See Illegal Encodings 23.24
			// https://www.khronos.org/registry/DataFormat/specs/1.3/dataformat.1.3.inline.html#_illegal_encodings
			assert((total_weight_bits >= 24) && (total_weight_bits <= 96));

			int ccs_bit_pos = 128 - total_weight_bits - ASTC_CCS_BITS;
			astc_set_bits_1_to_9(pDst, ccs_bit_pos, pBlock->m_ccs, ASTC_CCS_BITS);
		}

		const int num_cem_pairs = (1 + (pBlock->m_cem >> 2)) * pBlock->m_subsets;
		assert(num_cem_pairs <= 9);

		astc_pack_bise(pDst, pBlock->m_endpoints, bit_pos, num_cem_pairs * 2, g_uastc_mode_endpoint_ranges[uastc_mode]);

		// Write the weight bits in reverse bit order.
		switch (bits_per_weight)
		{
		case 1:
		{
			const uint32_t N = 1;
			for (int i = 0; i < total_weights; i++)
			{
				const uint32_t ofs = 128 - N - i;
				assert((ofs >> 3) < 16);
				pDst_bytes[ofs >> 3] |= (pBlock->m_weights[i] << (ofs & 7));
			}
			break;
		}
		case 2:
		{
			const uint32_t N = 2;
			for (int i = 0; i < total_weights; i++)
			{
				static const uint8_t s_reverse_bits2[4] = { 0, 2, 1, 3 };
				const uint32_t ofs = 128 - N - (i * N);
				assert((ofs >> 3) < 16);
				pDst_bytes[ofs >> 3] |= (s_reverse_bits2[pBlock->m_weights[i]] << (ofs & 7));
			}
			break;
		}
		case 3:
		{
			const uint32_t N = 3;
			for (int i = 0; i < total_weights; i++)
			{
				static const uint8_t s_reverse_bits3[8] = { 0, 4, 2, 6, 1, 5, 3, 7 };

				const uint32_t ofs = 128 - N - (i * N);
				const uint32_t rev = s_reverse_bits3[pBlock->m_weights[i]] << (ofs & 7);

				uint32_t index = ofs >> 3;
				assert(index < 16);
				pDst_bytes[index++] |= rev & 0xFF;
				if (index < 16)
					pDst_bytes[index++] |= (rev >> 8);
			}
			break;
		}
		case 4:
		{
			const uint32_t N = 4;
			for (int i = 0; i < total_weights; i++)
			{
				static const uint8_t s_reverse_bits4[16] = { 0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15 };
				const int ofs = 128 - N - (i * N);
				assert(ofs >= 0 && (ofs >> 3) < 16);
				pDst_bytes[ofs >> 3] |= (s_reverse_bits4[pBlock->m_weights[i]] << (ofs & 7));
			}
			break;
		}
		case 5:
		{
			const uint32_t N = 5;
			for (int i = 0; i < total_weights; i++)
			{
				static const uint8_t s_reverse_bits5[32] = { 0, 16, 8, 24, 4, 20, 12, 28, 2, 18, 10, 26, 6, 22, 14, 30, 1, 17, 9, 25, 5, 21, 13, 29, 3, 19, 11, 27, 7, 23, 15, 31 };

				const uint32_t ofs = 128 - N - (i * N);
				const uint32_t rev = s_reverse_bits5[pBlock->m_weights[i]] << (ofs & 7);

				uint32_t index = ofs >> 3;
				assert(index < 16);
				pDst_bytes[index++] |= rev & 0xFF;
				if (index < 16)
					pDst_bytes[index++] |= (rev >> 8);
			}

			break;
		}
		default:
			assert(0);
			break;
		}

		return true;
	}

	const uint8_t* get_anchor_indices(uint32_t subsets, uint32_t mode, uint32_t common_pattern, const uint8_t*& pPartition_pattern)
	{
		const uint8_t* pSubset_anchor_indices = g_zero_pattern;
		pPartition_pattern = g_zero_pattern;

		if (subsets >= 2)
		{
			if (subsets == 3)
			{
				pPartition_pattern = &g_astc_bc7_patterns3[common_pattern][0];
				pSubset_anchor_indices = &g_astc_bc7_pattern3_anchors[common_pattern][0];
			}
			else if (mode == 7)
			{
				pPartition_pattern = &g_bc7_3_astc2_patterns2[common_pattern][0];
				pSubset_anchor_indices = &g_bc7_3_astc2_patterns2_anchors[common_pattern][0];
			}
			else
			{
				pPartition_pattern = &g_astc_bc7_patterns2[common_pattern][0];
				pSubset_anchor_indices = &g_astc_bc7_pattern2_anchors[common_pattern][0];
			}
		}

		return pSubset_anchor_indices;
	}

	static inline uint32_t read_bit(const uint8_t* pBuf, uint32_t& bit_offset)
	{
		uint32_t byte_bits = pBuf[bit_offset >> 3] >> (bit_offset & 7);
		bit_offset += 1;
		return byte_bits & 1;
	}

	static inline uint32_t read_bits1_to_9(const uint8_t* pBuf, uint32_t& bit_offset, uint32_t codesize)
	{
		assert(codesize <= 9);
		if (!codesize)
			return 0;

		if ((BASISD_IS_BIG_ENDIAN) || (!BASISD_USE_UNALIGNED_WORD_READS) || (bit_offset >= 112))
		{
			const uint8_t* pBytes = &pBuf[bit_offset >> 3U];

			uint32_t byte_bit_offset = bit_offset & 7U;

			uint32_t bits = pBytes[0] >> byte_bit_offset;
			uint32_t bits_read = basisu::minimum<int>(codesize, 8 - byte_bit_offset);

			uint32_t bits_remaining = codesize - bits_read;
			if (bits_remaining)
				bits |= ((uint32_t)pBytes[1]) << bits_read;

			bit_offset += codesize;

			return bits & ((1U << codesize) - 1U);
		}

		uint32_t byte_bit_offset = bit_offset & 7U;
		const uint16_t w = *(const uint16_t *)(&pBuf[bit_offset >> 3U]);
		bit_offset += codesize;
		return (w >> byte_bit_offset) & ((1U << codesize) - 1U);
	}

	inline uint64_t read_bits64(const uint8_t* pBuf, uint32_t& bit_offset, uint32_t codesize)
	{
		assert(codesize <= 64U);
		uint64_t bits = 0;
		uint32_t total_bits = 0;

		while (total_bits < codesize)
		{
			uint32_t byte_bit_offset = bit_offset & 7U;
			uint32_t bits_to_read = basisu::minimum<int>(codesize - total_bits, 8U - byte_bit_offset);

			uint32_t byte_bits = pBuf[bit_offset >> 3U] >> byte_bit_offset;
			byte_bits &= ((1U << bits_to_read) - 1U);

			bits |= ((uint64_t)(byte_bits) << total_bits);

			total_bits += bits_to_read;
			bit_offset += bits_to_read;
		}

		return bits;
	}

	static inline uint32_t read_bits1_to_9_fst(const uint8_t* pBuf, uint32_t& bit_offset, uint32_t codesize)
	{
		assert(codesize <= 9);
		if (!codesize)
			return 0;
		assert(bit_offset < 112);

		if ((BASISD_IS_BIG_ENDIAN) || (!BASISD_USE_UNALIGNED_WORD_READS))
		{
			const uint8_t* pBytes = &pBuf[bit_offset >> 3U];

			uint32_t byte_bit_offset = bit_offset & 7U;

			uint32_t bits = pBytes[0] >> byte_bit_offset;
			uint32_t bits_read = basisu::minimum<int>(codesize, 8 - byte_bit_offset);

			uint32_t bits_remaining = codesize - bits_read;
			if (bits_remaining)
				bits |= ((uint32_t)pBytes[1]) << bits_read;

			bit_offset += codesize;

			return bits & ((1U << codesize) - 1U);
		}
		else
		{
			uint32_t byte_bit_offset = bit_offset & 7U;
			const uint16_t w = *(const uint16_t*)(&pBuf[bit_offset >> 3U]);
			bit_offset += codesize;
			return (w >> byte_bit_offset) & ((1U << codesize) - 1U);
		}
	}

	bool unpack_uastc(const uastc_block& blk, unpacked_uastc_block& unpacked, bool blue_contract_check, bool read_hints)
	{
		//memset(&unpacked, 0, sizeof(unpacked));
				
#if 0
		uint8_t table[128];
		memset(table, 0xFF, sizeof(table));

		{
			for (uint32_t mode = 0; mode <= TOTAL_UASTC_MODES; mode++)
			{
				const uint32_t code = g_uastc_mode_huff_codes[mode][0];
				const uint32_t codesize = g_uastc_mode_huff_codes[mode][1];

				table[code] = mode;

				uint32_t bits_left = 7 - codesize;
				for (uint32_t i = 0; i < (1 << bits_left); i++)
					table[code | (i << codesize)] = mode;
			}

			for (uint32_t i = 0; i < 128; i++)
				printf("%u,", table[i]);
			exit(0);
		}
#endif

		const int mode = g_uastc_huff_modes[blk.m_bytes[0] & 127];
		if (mode >= (int)TOTAL_UASTC_MODES)
			return false;

		unpacked.m_mode = mode;
		unpacked.m_common_pattern = 0;

		uint32_t bit_ofs = g_uastc_mode_huff_codes[mode][1];

		if (mode == UASTC_MODE_INDEX_SOLID_COLOR)
		{
			unpacked.m_solid_color.r = (uint8_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 8);
			unpacked.m_solid_color.g = (uint8_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 8);
			unpacked.m_solid_color.b = (uint8_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 8);
			unpacked.m_solid_color.a = (uint8_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 8);

			if (read_hints)
			{
				unpacked.m_etc1_flip = false;
				unpacked.m_etc1_diff = read_bit(blk.m_bytes, bit_ofs) != 0;
				unpacked.m_etc1_inten0 = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 3);
				unpacked.m_etc1_inten1 = 0;
				unpacked.m_etc1_selector = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 2);
				unpacked.m_etc1_r = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 5);
				unpacked.m_etc1_g = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 5);
				unpacked.m_etc1_b = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 5);
				unpacked.m_etc1_bias = 0;
				unpacked.m_etc2_hints = 0;
			}

			return true;
		}
				
		if (read_hints)
		{
			if (g_uastc_mode_has_bc1_hint0[mode])
				unpacked.m_bc1_hint0 = read_bit(blk.m_bytes, bit_ofs) != 0;
			else
				unpacked.m_bc1_hint0 = false;

			if (g_uastc_mode_has_bc1_hint1[mode])
				unpacked.m_bc1_hint1 = read_bit(blk.m_bytes, bit_ofs) != 0;
			else
				unpacked.m_bc1_hint1 = false;

			unpacked.m_etc1_flip = read_bit(blk.m_bytes, bit_ofs) != 0;
			unpacked.m_etc1_diff = read_bit(blk.m_bytes, bit_ofs) != 0;
			unpacked.m_etc1_inten0 = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 3);
			unpacked.m_etc1_inten1 = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 3);

			if (g_uastc_mode_has_etc1_bias[mode])
				unpacked.m_etc1_bias = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 5);
			else
				unpacked.m_etc1_bias = 0;

			if (g_uastc_mode_has_alpha[mode])
			{
				unpacked.m_etc2_hints = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 8);
				//assert(unpacked.m_etc2_hints > 0);
			}
			else
				unpacked.m_etc2_hints = 0;
		}
		else
			bit_ofs += g_uastc_mode_total_hint_bits[mode];
				
		uint32_t subsets = 1;
		switch (mode)
		{
		case 2:
		case 4:
		case 7:
		case 9:
		case 16:
			unpacked.m_common_pattern = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 5);
			subsets = 2;
			break;
		case 3:
			unpacked.m_common_pattern = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 4);
			subsets = 3;
			break;
		default:
			break;
		}

		uint32_t part_seed = 0;
		switch (mode)
		{
		case 2:
		case 4:
		case 9:
		case 16:
			if (unpacked.m_common_pattern >= TOTAL_ASTC_BC7_COMMON_PARTITIONS2)
				return false;

			part_seed = g_astc_bc7_common_partitions2[unpacked.m_common_pattern].m_astc;
			break;
		case 3:
			if (unpacked.m_common_pattern >= TOTAL_ASTC_BC7_COMMON_PARTITIONS3)
				return false;

			part_seed = g_astc_bc7_common_partitions3[unpacked.m_common_pattern].m_astc;
			break;
		case 7:
			if (unpacked.m_common_pattern >= TOTAL_BC7_3_ASTC2_COMMON_PARTITIONS)
				return false;

			part_seed = g_bc7_3_astc2_common_partitions[unpacked.m_common_pattern].m_astc2;
			break;
		default:
			break;
		}

		uint32_t total_planes = 1;
		switch (mode)
		{
		case 6:
		case 11:
		case 13:
			unpacked.m_astc.m_ccs = (int)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 2);
			total_planes = 2;
			break;
		case 17:
			unpacked.m_astc.m_ccs = 3;
			total_planes = 2;
			break;
		default:
			break;
		}

		unpacked.m_astc.m_dual_plane = (total_planes == 2);

		unpacked.m_astc.m_subsets = subsets;
		unpacked.m_astc.m_partition_seed = part_seed;

		const uint32_t total_comps = g_uastc_mode_comps[mode];

		const uint32_t weight_bits = g_uastc_mode_weight_bits[mode];

		unpacked.m_astc.m_weight_range = g_uastc_mode_weight_ranges[mode];

		const uint32_t total_values = total_comps * 2 * subsets;
		const uint32_t endpoint_range = g_uastc_mode_endpoint_ranges[mode];

		const uint32_t cem = g_uastc_mode_cem[mode];
		unpacked.m_astc.m_cem = cem;

		const uint32_t ep_bits = g_astc_bise_range_table[endpoint_range][0];
		const uint32_t ep_trits = g_astc_bise_range_table[endpoint_range][1];
		const uint32_t ep_quints = g_astc_bise_range_table[endpoint_range][2];

		uint32_t total_tqs = 0;
		uint32_t bundle_size = 0, mul = 0;
		if (ep_trits)
		{
			total_tqs = (total_values + 4) / 5;
			bundle_size = 5;
			mul = 3;
		}
		else if (ep_quints)
		{
			total_tqs = (total_values + 2) / 3;
			bundle_size = 3;
			mul = 5;
		}

		uint32_t tq_values[8];
		for (uint32_t i = 0; i < total_tqs; i++)
		{
			uint32_t num_bits = ep_trits ? 8 : 7;
			if (i == (total_tqs - 1))
			{
				uint32_t num_remaining = total_values - (total_tqs - 1) * bundle_size;
				if (ep_trits)
				{
					switch (num_remaining)
					{
					case 1: num_bits = 2; break;
					case 2: num_bits = 4; break;
					case 3: num_bits = 5; break;
					case 4: num_bits = 7; break;
					default: break;
					}
				}
				else if (ep_quints)
				{
					switch (num_remaining)
					{
					case 1: num_bits = 3; break;
					case 2: num_bits = 5; break;
					default: break;
					}
				}
			}

			tq_values[i] = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, num_bits);
		} // i

		uint32_t accum = 0;
		uint32_t accum_remaining = 0;
		uint32_t next_tq_index = 0;

		for (uint32_t i = 0; i < total_values; i++)
		{
			uint32_t value = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, ep_bits);

			if (total_tqs)
			{
				if (!accum_remaining)
				{
					assert(next_tq_index < total_tqs);
					accum = tq_values[next_tq_index++];
					accum_remaining = bundle_size;
				}

				// TODO: Optimize with tables
				uint32_t v = accum % mul;
				accum /= mul;
				accum_remaining--;

				value |= (v << ep_bits);
			}

			unpacked.m_astc.m_endpoints[i] = (uint8_t)value;
		}

		const uint8_t* pPartition_pattern;
		const uint8_t* pSubset_anchor_indices = get_anchor_indices(subsets, mode, unpacked.m_common_pattern, pPartition_pattern);

#ifdef _DEBUG
		for (uint32_t i = 0; i < 16; i++)
			assert(pPartition_pattern[i] == astc_compute_texel_partition(part_seed, i & 3, i >> 2, 0, subsets, true));

		for (uint32_t subset_index = 0; subset_index < subsets; subset_index++)
		{
			uint32_t anchor_index = 0;

			for (uint32_t i = 0; i < 16; i++)
			{
				if (pPartition_pattern[i] == subset_index)
				{
					anchor_index = i;
					break;
				}
			}

			assert(pSubset_anchor_indices[subset_index] == anchor_index);
		}
#endif

#if 0
		const uint32_t total_planes_shift = total_planes - 1;
		for (uint32_t i = 0; i < 16 * total_planes; i++)
		{
			uint32_t num_bits = weight_bits;
			for (uint32_t s = 0; s < subsets; s++)
			{
				if (pSubset_anchor_indices[s] == (i >> total_planes_shift))
				{
					num_bits--;
					break;
				}
			}

			unpacked.m_astc.m_weights[i] = (uint8_t)read_bits1_to_9(blk.m_bytes, bit_ofs, num_bits);
		}
#endif

		if (mode == 18)
		{
			// Mode 18 is the only mode with more than 64 weight bits.
			for (uint32_t i = 0; i < 16; i++)
				unpacked.m_astc.m_weights[i] = (uint8_t)read_bits1_to_9(blk.m_bytes, bit_ofs, i ? weight_bits : (weight_bits - 1));
		}
		else
		{
			// All other modes have <= 64 weight bits.
			uint64_t bits;
			
			// Read the weight bits
			if ((BASISD_IS_BIG_ENDIAN) || (!BASISD_USE_UNALIGNED_WORD_READS))
				bits = read_bits64(blk.m_bytes, bit_ofs, basisu::minimum<int>(64, 128 - (int)bit_ofs));
			else
			{
				bits = blk.m_dwords[2];
				bits |= (((uint64_t)blk.m_dwords[3]) << 32U);
				
				if (bit_ofs >= 64U)
					bits >>= (bit_ofs - 64U);
				else
				{
					assert(bit_ofs >= 56U);
					
					uint32_t bits_needed = 64U - bit_ofs;
					bits <<= bits_needed;
					bits |= (blk.m_bytes[7] >> (8U - bits_needed));
				}
			}
						
			bit_ofs = 0;

			const uint32_t mask = (1U << weight_bits) - 1U;
			const uint32_t anchor_mask = (1U << (weight_bits - 1U)) - 1U;
			
			if (total_planes == 2)
			{
				// Dual plane modes always have a single subset, and the first 2 weights are anchors.

				unpacked.m_astc.m_weights[0] = (uint8_t)((uint32_t)(bits >> bit_ofs) & anchor_mask);
				bit_ofs += (weight_bits - 1);
				
				unpacked.m_astc.m_weights[1] = (uint8_t)((uint32_t)(bits >> bit_ofs) & anchor_mask);
				bit_ofs += (weight_bits - 1);

				for (uint32_t i = 2; i < 32; i++)
				{
					unpacked.m_astc.m_weights[i] = (uint8_t)((uint32_t)(bits >> bit_ofs) & mask);
					bit_ofs += weight_bits;
				}
			}
			else
			{
				if (subsets == 1)
				{
					// Specialize the single subset case.
					if (weight_bits == 4)
					{
						assert(bit_ofs == 0);
						
						// Specialize the most common case: 4-bit weights.
						unpacked.m_astc.m_weights[0] = (uint8_t)((uint32_t)(bits) & 7);
						unpacked.m_astc.m_weights[1] = (uint8_t)((uint32_t)(bits >> 3) & 15);
						unpacked.m_astc.m_weights[2] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 1)) & 15);
						unpacked.m_astc.m_weights[3] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 2)) & 15);

						unpacked.m_astc.m_weights[4] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 3)) & 15);
						unpacked.m_astc.m_weights[5] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 4)) & 15);
						unpacked.m_astc.m_weights[6] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 5)) & 15);
						unpacked.m_astc.m_weights[7] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 6)) & 15);

						unpacked.m_astc.m_weights[8] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 7)) & 15);
						unpacked.m_astc.m_weights[9] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 8)) & 15);
						unpacked.m_astc.m_weights[10] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 9)) & 15);
						unpacked.m_astc.m_weights[11] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 10)) & 15);

						unpacked.m_astc.m_weights[12] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 11)) & 15);
						unpacked.m_astc.m_weights[13] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 12)) & 15);
						unpacked.m_astc.m_weights[14] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 13)) & 15);
						unpacked.m_astc.m_weights[15] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 14)) & 15);
					}
					else
					{
						// First weight is always an anchor.
						unpacked.m_astc.m_weights[0] = (uint8_t)((uint32_t)(bits >> bit_ofs) & anchor_mask);
						bit_ofs += (weight_bits - 1);

						for (uint32_t i = 1; i < 16; i++)
						{
							unpacked.m_astc.m_weights[i] = (uint8_t)((uint32_t)(bits >> bit_ofs) & mask);
							bit_ofs += weight_bits;
						}
					}
				}
				else
				{
					const uint32_t a0 = pSubset_anchor_indices[0], a1 = pSubset_anchor_indices[1], a2 = pSubset_anchor_indices[2];

					for (uint32_t i = 0; i < 16; i++)
					{
						if ((i == a0) || (i == a1) || (i == a2))
						{
							unpacked.m_astc.m_weights[i] = (uint8_t)((uint32_t)(bits >> bit_ofs) & anchor_mask);
							bit_ofs += (weight_bits - 1);
						}
						else
						{
							unpacked.m_astc.m_weights[i] = (uint8_t)((uint32_t)(bits >> bit_ofs) & mask);
							bit_ofs += weight_bits;
						}
					}
				}
			}
		}

		if ((blue_contract_check) && (total_comps >= 3))
		{
			// We only need to disable ASTC Blue Contraction when we'll be packing to ASTC. The other transcoders don't care.
			bool invert_subset[3] = { false, false, false };
			bool any_flag = false;

			for (uint32_t subset_index = 0; subset_index < subsets; subset_index++)
			{
				const int s0 = g_astc_unquant[endpoint_range][unpacked.m_astc.m_endpoints[subset_index * total_comps * 2 + 0]].m_unquant +
					g_astc_unquant[endpoint_range][unpacked.m_astc.m_endpoints[subset_index * total_comps * 2 + 2]].m_unquant +
					g_astc_unquant[endpoint_range][unpacked.m_astc.m_endpoints[subset_index * total_comps * 2 + 4]].m_unquant;

				const int s1 = g_astc_unquant[endpoint_range][unpacked.m_astc.m_endpoints[subset_index * total_comps * 2 + 1]].m_unquant +
					g_astc_unquant[endpoint_range][unpacked.m_astc.m_endpoints[subset_index * total_comps * 2 + 3]].m_unquant +
					g_astc_unquant[endpoint_range][unpacked.m_astc.m_endpoints[subset_index * total_comps * 2 + 5]].m_unquant;

				if (s1 < s0)
				{
					for (uint32_t c = 0; c < total_comps; c++)
						std::swap(unpacked.m_astc.m_endpoints[subset_index * total_comps * 2 + c * 2 + 0], unpacked.m_astc.m_endpoints[subset_index * total_comps * 2 + c * 2 + 1]);

					invert_subset[subset_index] = true;
					any_flag = true;
				}
			}

			if (any_flag)
			{
				const uint32_t weight_mask = (1 << weight_bits) - 1;

				for (uint32_t i = 0; i < 16; i++)
				{
					uint32_t subset = pPartition_pattern[i];

					if (invert_subset[subset])
					{
						unpacked.m_astc.m_weights[i * total_planes] = (uint8_t)(weight_mask - unpacked.m_astc.m_weights[i * total_planes]);

						if (total_planes == 2)
							unpacked.m_astc.m_weights[i * total_planes + 1] = (uint8_t)(weight_mask - unpacked.m_astc.m_weights[i * total_planes + 1]);
					}
				}
			}
		}

		return true;
	}

	static const uint32_t* g_astc_weight_tables[6] = { nullptr, g_bc7_weights1, g_bc7_weights2, g_bc7_weights3, g_astc_weights4, g_astc_weights5 };

	bool unpack_uastc(uint32_t mode, uint32_t common_pattern, const color32& solid_color, const astc_block_desc& astc, color32* pPixels, bool srgb)
	{
		if (mode == UASTC_MODE_INDEX_SOLID_COLOR)
		{
			for (uint32_t i = 0; i < 16; i++)
				pPixels[i] = solid_color;
			return true;
		}

		color32 endpoints[3][2];

		const uint32_t total_subsets = g_uastc_mode_subsets[mode];
		const uint32_t total_comps = basisu::minimum<uint32_t>(4U, g_uastc_mode_comps[mode]);
		const uint32_t endpoint_range = g_uastc_mode_endpoint_ranges[mode];
		const uint32_t total_planes = g_uastc_mode_planes[mode];
		const uint32_t weight_bits = g_uastc_mode_weight_bits[mode];
		const uint32_t weight_levels = 1 << weight_bits;

		for (uint32_t subset_index = 0; subset_index < total_subsets; subset_index++)
		{
			if (total_comps == 2)
			{
				const uint32_t ll = g_astc_unquant[endpoint_range][astc.m_endpoints[subset_index * total_comps * 2 + 0 * 2 + 0]].m_unquant;
				const uint32_t lh = g_astc_unquant[endpoint_range][astc.m_endpoints[subset_index * total_comps * 2 + 0 * 2 + 1]].m_unquant;

				const uint32_t al = g_astc_unquant[endpoint_range][astc.m_endpoints[subset_index * total_comps * 2 + 1 * 2 + 0]].m_unquant;
				const uint32_t ah = g_astc_unquant[endpoint_range][astc.m_endpoints[subset_index * total_comps * 2 + 1 * 2 + 1]].m_unquant;

				endpoints[subset_index][0].set_noclamp_rgba(ll, ll, ll, al);
				endpoints[subset_index][1].set_noclamp_rgba(lh, lh, lh, ah);
			}
			else
			{
				for (uint32_t comp_index = 0; comp_index < total_comps; comp_index++)
				{
					endpoints[subset_index][0][comp_index] = g_astc_unquant[endpoint_range][astc.m_endpoints[subset_index * total_comps * 2 + comp_index * 2 + 0]].m_unquant;
					endpoints[subset_index][1][comp_index] = g_astc_unquant[endpoint_range][astc.m_endpoints[subset_index * total_comps * 2 + comp_index * 2 + 1]].m_unquant;
				}
				for (uint32_t comp_index = total_comps; comp_index < 4; comp_index++)
				{
					endpoints[subset_index][0][comp_index] = 255;
					endpoints[subset_index][1][comp_index] = 255;
				}
			}
		}

		color32 block_colors[3][32];

		const uint32_t* pWeights = g_astc_weight_tables[weight_bits];

		for (uint32_t subset_index = 0; subset_index < total_subsets; subset_index++)
		{
			for (uint32_t l = 0; l < weight_levels; l++)
			{
				if (total_comps == 2)
				{
					const uint8_t lc = (uint8_t)astc_interpolate(endpoints[subset_index][0][0], endpoints[subset_index][1][0], pWeights[l], srgb);
					const uint8_t ac = (uint8_t)astc_interpolate(endpoints[subset_index][0][3], endpoints[subset_index][1][3], pWeights[l], srgb);

					block_colors[subset_index][l].set(lc, lc, lc, ac);
				}
				else
				{
					uint32_t comp_index;
					for (comp_index = 0; comp_index < total_comps; comp_index++)
						block_colors[subset_index][l][comp_index] = (uint8_t)astc_interpolate(endpoints[subset_index][0][comp_index], endpoints[subset_index][1][comp_index], pWeights[l], srgb);

					for (; comp_index < 4; comp_index++)
						block_colors[subset_index][l][comp_index] = 255;
				}
			}
		}

		const uint8_t* pPartition_pattern = g_zero_pattern;

		if (total_subsets >= 2)
		{
			if (total_subsets == 3)
				pPartition_pattern = &g_astc_bc7_patterns3[common_pattern][0];
			else if (mode == 7)
				pPartition_pattern = &g_bc7_3_astc2_patterns2[common_pattern][0];
			else
				pPartition_pattern = &g_astc_bc7_patterns2[common_pattern][0];

#ifdef _DEBUG
			for (uint32_t i = 0; i < 16; i++)
			{
				assert(pPartition_pattern[i] == (uint8_t)astc_compute_texel_partition(astc.m_partition_seed, i & 3, i >> 2, 0, total_subsets, true));
			}
#endif
		}

		if (total_planes == 1)
		{
			if (total_subsets == 1)
			{
				for (uint32_t i = 0; i < 16; i++)
				{
					assert(astc.m_weights[i] < weight_levels);
					pPixels[i] = block_colors[0][astc.m_weights[i]];
				}
			}
			else
			{
				for (uint32_t i = 0; i < 16; i++)
				{
					assert(astc.m_weights[i] < weight_levels);
					pPixels[i] = block_colors[pPartition_pattern[i]][astc.m_weights[i]];
				}
			}
		}
		else
		{
			assert(total_subsets == 1);

			for (uint32_t i = 0; i < 16; i++)
			{
				const uint32_t subset_index = 0; // pPartition_pattern[i];

				const uint32_t weight_index0 = astc.m_weights[i * 2];
				const uint32_t weight_index1 = astc.m_weights[i * 2 + 1];

				assert(weight_index0 < weight_levels && weight_index1 < weight_levels);

				color32& c = pPixels[i];
				for (uint32_t comp = 0; comp < 4; comp++)
				{
					if ((int)comp == astc.m_ccs)
						c[comp] = block_colors[subset_index][weight_index1][comp];
					else
						c[comp] = block_colors[subset_index][weight_index0][comp];
				}
			}
		}

		return true;
	}

	bool unpack_uastc(const unpacked_uastc_block& unpacked_blk, color32* pPixels, bool srgb)
	{
		return unpack_uastc(unpacked_blk.m_mode, unpacked_blk.m_common_pattern, unpacked_blk.m_solid_color, unpacked_blk.m_astc, pPixels, srgb);
	}

	bool unpack_uastc(const uastc_block& blk, color32* pPixels, bool srgb)
	{
		unpacked_uastc_block unpacked_blk;

		if (!unpack_uastc(blk, unpacked_blk, false, false))
			return false;

		return unpack_uastc(unpacked_blk, pPixels, srgb);
	}

	// Determines the best shared pbits to use to encode xl/xh
	static void determine_shared_pbits(
		uint32_t total_comps, uint32_t comp_bits, float xl[4], float xh[4],
		color_quad_u8& bestMinColor, color_quad_u8& bestMaxColor, uint32_t best_pbits[2])
	{
		const uint32_t total_bits = comp_bits + 1;
		assert(total_bits >= 4 && total_bits <= 8);

		const int iscalep = (1 << total_bits) - 1;
		const float scalep = (float)iscalep;

		float best_err = 1e+9f;

		for (int p = 0; p < 2; p++)
		{
			color_quad_u8 xMinColor, xMaxColor;
			for (uint32_t c = 0; c < 4; c++)
			{
				xMinColor.m_c[c] = (uint8_t)(clampi(((int)((xl[c] * scalep - p) / 2.0f + .5f)) * 2 + p, p, iscalep - 1 + p));
				xMaxColor.m_c[c] = (uint8_t)(clampi(((int)((xh[c] * scalep - p) / 2.0f + .5f)) * 2 + p, p, iscalep - 1 + p));
			}

			color_quad_u8 scaledLow, scaledHigh;

			for (uint32_t i = 0; i < 4; i++)
			{
				scaledLow.m_c[i] = (xMinColor.m_c[i] << (8 - total_bits));
				scaledLow.m_c[i] |= (scaledLow.m_c[i] >> total_bits);
				assert(scaledLow.m_c[i] <= 255);

				scaledHigh.m_c[i] = (xMaxColor.m_c[i] << (8 - total_bits));
				scaledHigh.m_c[i] |= (scaledHigh.m_c[i] >> total_bits);
				assert(scaledHigh.m_c[i] <= 255);
			}

			float err = 0;
			for (uint32_t i = 0; i < total_comps; i++)
				err += basisu::squaref((scaledLow.m_c[i] / 255.0f) - xl[i]) + basisu::squaref((scaledHigh.m_c[i] / 255.0f) - xh[i]);

			if (err < best_err)
			{
				best_err = err;
				best_pbits[0] = p;
				best_pbits[1] = p;
				for (uint32_t j = 0; j < 4; j++)
				{
					bestMinColor.m_c[j] = xMinColor.m_c[j] >> 1;
					bestMaxColor.m_c[j] = xMaxColor.m_c[j] >> 1;
				}
			}
		}
	}

	// Determines the best unique pbits to use to encode xl/xh
	static void determine_unique_pbits(
		uint32_t total_comps, uint32_t comp_bits, float xl[4], float xh[4],
		color_quad_u8& bestMinColor, color_quad_u8& bestMaxColor, uint32_t best_pbits[2])
	{
		const uint32_t total_bits = comp_bits + 1;
		const int iscalep = (1 << total_bits) - 1;
		const float scalep = (float)iscalep;

		float best_err0 = 1e+9f;
		float best_err1 = 1e+9f;

		for (int p = 0; p < 2; p++)
		{
			color_quad_u8 xMinColor, xMaxColor;

			for (uint32_t c = 0; c < 4; c++)
			{
				xMinColor.m_c[c] = (uint8_t)(clampi(((int)((xl[c] * scalep - p) / 2.0f + .5f)) * 2 + p, p, iscalep - 1 + p));
				xMaxColor.m_c[c] = (uint8_t)(clampi(((int)((xh[c] * scalep - p) / 2.0f + .5f)) * 2 + p, p, iscalep - 1 + p));
			}

			color_quad_u8 scaledLow, scaledHigh;
			for (uint32_t i = 0; i < 4; i++)
			{
				scaledLow.m_c[i] = (xMinColor.m_c[i] << (8 - total_bits));
				scaledLow.m_c[i] |= (scaledLow.m_c[i] >> total_bits);
				assert(scaledLow.m_c[i] <= 255);

				scaledHigh.m_c[i] = (xMaxColor.m_c[i] << (8 - total_bits));
				scaledHigh.m_c[i] |= (scaledHigh.m_c[i] >> total_bits);
				assert(scaledHigh.m_c[i] <= 255);
			}

			float err0 = 0, err1 = 0;
			for (uint32_t i = 0; i < total_comps; i++)
			{
				err0 += basisu::squaref(scaledLow.m_c[i] - xl[i] * 255.0f);
				err1 += basisu::squaref(scaledHigh.m_c[i] - xh[i] * 255.0f);
			}

			if (err0 < best_err0)
			{
				best_err0 = err0;
				best_pbits[0] = p;

				bestMinColor.m_c[0] = xMinColor.m_c[0] >> 1;
				bestMinColor.m_c[1] = xMinColor.m_c[1] >> 1;
				bestMinColor.m_c[2] = xMinColor.m_c[2] >> 1;
				bestMinColor.m_c[3] = xMinColor.m_c[3] >> 1;
			}

			if (err1 < best_err1)
			{
				best_err1 = err1;
				best_pbits[1] = p;

				bestMaxColor.m_c[0] = xMaxColor.m_c[0] >> 1;
				bestMaxColor.m_c[1] = xMaxColor.m_c[1] >> 1;
				bestMaxColor.m_c[2] = xMaxColor.m_c[2] >> 1;
				bestMaxColor.m_c[3] = xMaxColor.m_c[3] >> 1;
			}
		}
	}

	bool transcode_uastc_to_astc(const uastc_block& src_blk, void* pDst)
	{
		unpacked_uastc_block unpacked_src_blk;
		if (!unpack_uastc(src_blk, unpacked_src_blk, true, false))
			return false;

		bool success = false;
		if (unpacked_src_blk.m_mode == UASTC_MODE_INDEX_SOLID_COLOR)
		{
			pack_astc_solid_block(pDst, unpacked_src_blk.m_solid_color);
			success = true;
		}
		else
		{
			success = pack_astc_block(static_cast<uint32_t*>(pDst), &unpacked_src_blk.m_astc, unpacked_src_blk.m_mode);
		}

		return success;
	}

	bool transcode_uastc_to_bc7(const unpacked_uastc_block& unpacked_src_blk, bc7_optimization_results& dst_blk)
	{
		memset(&dst_blk, 0, sizeof(dst_blk));

		const uint32_t mode = unpacked_src_blk.m_mode;

		const uint32_t endpoint_range = g_uastc_mode_endpoint_ranges[mode];
		const uint32_t total_comps = g_uastc_mode_comps[mode];

		switch (mode)
		{
		case 0:
		case 5:
		case 10:
		case 12:
		case 14:
		case 15:
		case 18:
		{
			// MODE 0: DualPlane: 0, WeightRange: 8 (16), Subsets: 1, EndpointRange: 19 (192) - BC7 MODE6 RGB
			// MODE 5: DualPlane: 0, WeightRange : 5 (8), Subsets : 1, EndpointRange : 20 (256) - BC7 MODE6 RGB
			// MODE 10 DualPlane: 0, WeightRange: 8 (16), Subsets: 1, EndpointRange: 13 (48) - BC7 MODE6
			// MODE 12: DualPlane: 0, WeightRange : 5 (8), Subsets : 1, EndpointRange : 19 (192) - BC7 MODE6
			// MODE 14: DualPlane: 0, WeightRange : 2 (4), Subsets : 1, EndpointRange : 20 (256) - BC7 MODE6
			// MODE 18: DualPlane: 0, WeightRange : 11 (32), Subsets : 1, CEM : 8, EndpointRange : 11 (32) - BC7 MODE6
			// MODE 15: DualPlane: 0, WeightRange : 8 (16), Subsets : 1, CEM : 4 (LA Direct), EndpointRange : 20 (256) - BC7 MODE6
			dst_blk.m_mode = 6;

			float xl[4], xh[4];
			if (total_comps == 2)
			{
				xl[0] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[0]].m_unquant / 255.0f;
				xh[0] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[1]].m_unquant / 255.0f;

				xl[1] = xl[0];
				xh[1] = xh[0];

				xl[2] = xl[0];
				xh[2] = xh[0];

				xl[3] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[2]].m_unquant / 255.0f;
				xh[3] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[3]].m_unquant / 255.0f;
			}
			else
			{
				xl[0] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[0]].m_unquant / 255.0f;
				xl[1] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[2]].m_unquant / 255.0f;
				xl[2] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[4]].m_unquant / 255.0f;

				xh[0] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[1]].m_unquant / 255.0f;
				xh[1] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[3]].m_unquant / 255.0f;
				xh[2] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[5]].m_unquant / 255.0f;

				if (total_comps == 4)
				{
					xl[3] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[6]].m_unquant / 255.0f;
					xh[3] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[7]].m_unquant / 255.0f;
				}
				else
				{
					xl[3] = 1.0f;
					xh[3] = 1.0f;
				}
			}

			uint32_t best_pbits[2];
			color_quad_u8 bestMinColor, bestMaxColor;
			determine_unique_pbits((total_comps == 2) ? 4 : total_comps, 7, xl, xh, bestMinColor, bestMaxColor, best_pbits);

			dst_blk.m_low[0] = bestMinColor;
			dst_blk.m_high[0] = bestMaxColor;

			if (total_comps == 3)
			{
				dst_blk.m_low[0].m_c[3] = 127;
				dst_blk.m_high[0].m_c[3] = 127;
			}

			dst_blk.m_pbits[0][0] = best_pbits[0];
			dst_blk.m_pbits[0][1] = best_pbits[1];

			if (mode == 18)
			{
				const uint8_t s_bc7_5_to_4[32] = { 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 6, 7, 8, 9, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 14, 15, 15 };
				for (uint32_t i = 0; i < 16; i++)
					dst_blk.m_selectors[i] = s_bc7_5_to_4[unpacked_src_blk.m_astc.m_weights[i]];
			}
			else if (mode == 14)
			{
				const uint8_t s_bc7_2_to_4[4] = { 0, 5, 10, 15 };
				for (uint32_t i = 0; i < 16; i++)
					dst_blk.m_selectors[i] = s_bc7_2_to_4[unpacked_src_blk.m_astc.m_weights[i]];
			}
			else if ((mode == 5) || (mode == 12))
			{
				const uint8_t s_bc7_3_to_4[8] = { 0, 2, 4, 6, 9, 11, 13, 15 };
				for (uint32_t i = 0; i < 16; i++)
					dst_blk.m_selectors[i] = s_bc7_3_to_4[unpacked_src_blk.m_astc.m_weights[i]];
			}
			else
			{
				for (uint32_t i = 0; i < 16; i++)
					dst_blk.m_selectors[i] = unpacked_src_blk.m_astc.m_weights[i];
			}

			break;
		}
		case 1:
		{
			// DualPlane: 0, WeightRange : 2 (4), Subsets : 1, EndpointRange : 20 (256) - BC7 MODE3
			// Mode 1 uses endpoint range 20 - no need to use ASTC dequant tables.
			dst_blk.m_mode = 3;

			float xl[4], xh[4];
			xl[0] = unpacked_src_blk.m_astc.m_endpoints[0] / 255.0f;
			xl[1] = unpacked_src_blk.m_astc.m_endpoints[2] / 255.0f;
			xl[2] = unpacked_src_blk.m_astc.m_endpoints[4] / 255.0f;
			xl[3] = 1.0f;

			xh[0] = unpacked_src_blk.m_astc.m_endpoints[1] / 255.0f;
			xh[1] = unpacked_src_blk.m_astc.m_endpoints[3] / 255.0f;
			xh[2] = unpacked_src_blk.m_astc.m_endpoints[5] / 255.0f;
			xh[3] = 1.0f;

			uint32_t best_pbits[2];
			color_quad_u8 bestMinColor, bestMaxColor;
			memset(&bestMinColor, 0, sizeof(bestMinColor));
			memset(&bestMaxColor, 0, sizeof(bestMaxColor));
			determine_unique_pbits(3, 7, xl, xh, bestMinColor, bestMaxColor, best_pbits);

			for (uint32_t i = 0; i < 3; i++)
			{
				dst_blk.m_low[0].m_c[i] = bestMinColor.m_c[i];
				dst_blk.m_high[0].m_c[i] = bestMaxColor.m_c[i];
				dst_blk.m_low[1].m_c[i] = bestMinColor.m_c[i];
				dst_blk.m_high[1].m_c[i] = bestMaxColor.m_c[i];
			}
			dst_blk.m_pbits[0][0] = best_pbits[0];
			dst_blk.m_pbits[0][1] = best_pbits[1];
			dst_blk.m_pbits[1][0] = best_pbits[0];
			dst_blk.m_pbits[1][1] = best_pbits[1];

			for (uint32_t i = 0; i < 16; i++)
				dst_blk.m_selectors[i] = unpacked_src_blk.m_astc.m_weights[i];

			break;
		}
		case 2:
		{
			// 2. DualPlane: 0, WeightRange : 5 (8), Subsets : 2, EndpointRange : 8 (16) - BC7 MODE1 
			dst_blk.m_mode = 1;
			dst_blk.m_partition = g_astc_bc7_common_partitions2[unpacked_src_blk.m_common_pattern].m_bc7;

			const bool invert_partition = g_astc_bc7_common_partitions2[unpacked_src_blk.m_common_pattern].m_invert;

			float xl[4], xh[4];
			xl[3] = 1.0f;
			xh[3] = 1.0f;

			for (uint32_t subset = 0; subset < 2; subset++)
			{
				for (uint32_t i = 0; i < 3; i++)
				{
					uint32_t v = unpacked_src_blk.m_astc.m_endpoints[i * 2 + subset * 6];
					v = (v << 4) | v;
					xl[i] = v / 255.0f;

					v = unpacked_src_blk.m_astc.m_endpoints[i * 2 + subset * 6 + 1];
					v = (v << 4) | v;
					xh[i] = v / 255.0f;
				}

				uint32_t best_pbits[2] = { 0, 0 };
				color_quad_u8 bestMinColor, bestMaxColor;
				memset(&bestMinColor, 0, sizeof(bestMinColor));
				memset(&bestMaxColor, 0, sizeof(bestMaxColor));
				determine_shared_pbits(3, 6, xl, xh, bestMinColor, bestMaxColor, best_pbits);

				const uint32_t bc7_subset_index = invert_partition ? (1 - subset) : subset;

				for (uint32_t i = 0; i < 3; i++)
				{
					dst_blk.m_low[bc7_subset_index].m_c[i] = bestMinColor.m_c[i];
					dst_blk.m_high[bc7_subset_index].m_c[i] = bestMaxColor.m_c[i];
				}

				dst_blk.m_pbits[bc7_subset_index][0] = best_pbits[0];
			} // subset

			for (uint32_t i = 0; i < 16; i++)
				dst_blk.m_selectors[i] = unpacked_src_blk.m_astc.m_weights[i];

			break;
		}
		case 3:
		{
			// DualPlane: 0, WeightRange : 2 (4), Subsets : 3, EndpointRange : 7 (12) - BC7 MODE2
			dst_blk.m_mode = 2;
			dst_blk.m_partition = g_astc_bc7_common_partitions3[unpacked_src_blk.m_common_pattern].m_bc7;

			const uint32_t perm = g_astc_bc7_common_partitions3[unpacked_src_blk.m_common_pattern].m_astc_to_bc7_perm;

			for (uint32_t subset = 0; subset < 3; subset++)
			{
				for (uint32_t comp = 0; comp < 3; comp++)
				{
					uint32_t lo = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[comp * 2 + 0 + subset * 6]].m_unquant;
					uint32_t hi = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[comp * 2 + 1 + subset * 6]].m_unquant;

					// TODO: I think this can be improved by using tables like Basis Universal does with ETC1S conversion.
					lo = (lo * 31 + 127) / 255;
					hi = (hi * 31 + 127) / 255;

					const uint32_t bc7_subset_index = g_astc_to_bc7_partition_index_perm_tables[perm][subset];

					dst_blk.m_low[bc7_subset_index].m_c[comp] = (uint8_t)lo;
					dst_blk.m_high[bc7_subset_index].m_c[comp] = (uint8_t)hi;
				}
			}

			for (uint32_t i = 0; i < 16; i++)
				dst_blk.m_selectors[i] = unpacked_src_blk.m_astc.m_weights[i];

			break;
		}
		case 4:
		{
			// 4. DualPlane: 0, WeightRange: 2 (4), Subsets: 2, EndpointRange: 12 (40) - BC7 MODE3
			dst_blk.m_mode = 3;
			dst_blk.m_partition = g_astc_bc7_common_partitions2[unpacked_src_blk.m_common_pattern].m_bc7;

			const bool invert_partition = g_astc_bc7_common_partitions2[unpacked_src_blk.m_common_pattern].m_invert;

			float xl[4], xh[4];
			xl[3] = 1.0f;
			xh[3] = 1.0f;

			for (uint32_t subset = 0; subset < 2; subset++)
			{
				for (uint32_t i = 0; i < 3; i++)
				{
					xl[i] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[i * 2 + subset * 6]].m_unquant / 255.0f;
					xh[i] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[i * 2 + subset * 6 + 1]].m_unquant / 255.0f;
				}

				uint32_t best_pbits[2] = { 0, 0 };
				color_quad_u8 bestMinColor, bestMaxColor;
				memset(&bestMinColor, 0, sizeof(bestMinColor));
				memset(&bestMaxColor, 0, sizeof(bestMaxColor));
				determine_unique_pbits(3, 7, xl, xh, bestMinColor, bestMaxColor, best_pbits);

				const uint32_t bc7_subset_index = invert_partition ? (1 - subset) : subset;

				for (uint32_t i = 0; i < 3; i++)
				{
					dst_blk.m_low[bc7_subset_index].m_c[i] = bestMinColor.m_c[i];
					dst_blk.m_high[bc7_subset_index].m_c[i] = bestMaxColor.m_c[i];
				}
				dst_blk.m_low[bc7_subset_index].m_c[3] = 127;
				dst_blk.m_high[bc7_subset_index].m_c[3] = 127;

				dst_blk.m_pbits[bc7_subset_index][0] = best_pbits[0];
				dst_blk.m_pbits[bc7_subset_index][1] = best_pbits[1];

			} // subset

			for (uint32_t i = 0; i < 16; i++)
				dst_blk.m_selectors[i] = unpacked_src_blk.m_astc.m_weights[i];

			break;
		}
		case 6:
		case 11:
		case 13:
		case 17:
		{
			// MODE 6: DualPlane: 1, WeightRange : 2 (4), Subsets : 1, EndpointRange : 18 (160) - BC7 MODE5 RGB
			// MODE 11: DualPlane: 1, WeightRange: 2 (4), Subsets: 1, EndpointRange: 13 (48) - BC7 MODE5
			// MODE 13: DualPlane: 1, WeightRange: 0 (2), Subsets : 1, EndpointRange : 20 (256) - BC7 MODE5
			// MODE 17: DualPlane: 1, WeightRange: 2 (4), Subsets: 1, CEM: 4 (LA Direct), EndpointRange: 20 (256) - BC7 MODE5
			dst_blk.m_mode = 5;
			dst_blk.m_rotation = (unpacked_src_blk.m_astc.m_ccs + 1) & 3;

			if (total_comps == 2)
			{
				assert(unpacked_src_blk.m_astc.m_ccs == 3);

				dst_blk.m_low->m_c[0] = (uint8_t)((g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[0]].m_unquant * 127 + 127) / 255);
				dst_blk.m_high->m_c[0] = (uint8_t)((g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[1]].m_unquant * 127 + 127) / 255);

				dst_blk.m_low->m_c[1] = dst_blk.m_low->m_c[0];
				dst_blk.m_high->m_c[1] = dst_blk.m_high->m_c[0];

				dst_blk.m_low->m_c[2] = dst_blk.m_low->m_c[0];
				dst_blk.m_high->m_c[2] = dst_blk.m_high->m_c[0];

				dst_blk.m_low->m_c[3] = (uint8_t)(g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[2]].m_unquant);
				dst_blk.m_high->m_c[3] = (uint8_t)(g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[3]].m_unquant);
			}
			else
			{
				for (uint32_t astc_comp = 0; astc_comp < 4; astc_comp++)
				{
					uint32_t bc7_comp = astc_comp;
					// ASTC and BC7 handle dual plane component rotations differently:
					// ASTC: 2nd plane separately interpolates the CCS channel.
					// BC7: 2nd plane channel is swapped with alpha, 2nd plane controls alpha interpolation, then we swap alpha with the desired channel.
					if (astc_comp == (uint32_t)unpacked_src_blk.m_astc.m_ccs)
						bc7_comp = 3;
					else if (astc_comp == 3)
						bc7_comp = unpacked_src_blk.m_astc.m_ccs;

					uint32_t l = 255, h = 255;
					if (astc_comp < total_comps)
					{
						l = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[astc_comp * 2 + 0]].m_unquant;
						h = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[astc_comp * 2 + 1]].m_unquant;
					}

					if (bc7_comp < 3)
					{
						l = (l * 127 + 127) / 255;
						h = (h * 127 + 127) / 255;
					}

					dst_blk.m_low->m_c[bc7_comp] = (uint8_t)l;
					dst_blk.m_high->m_c[bc7_comp] = (uint8_t)h;
				}
			}

			if (mode == 13)
			{
				for (uint32_t i = 0; i < 16; i++)
				{
					dst_blk.m_selectors[i] = unpacked_src_blk.m_astc.m_weights[i * 2] ? 3 : 0;
					dst_blk.m_alpha_selectors[i] = unpacked_src_blk.m_astc.m_weights[i * 2 + 1] ? 3 : 0;
				}
			}
			else
			{
				for (uint32_t i = 0; i < 16; i++)
				{
					dst_blk.m_selectors[i] = unpacked_src_blk.m_astc.m_weights[i * 2];
					dst_blk.m_alpha_selectors[i] = unpacked_src_blk.m_astc.m_weights[i * 2 + 1];
				}
			}

			break;
		}
		case 7:
		{
			// DualPlane: 0, WeightRange : 2 (4), Subsets : 2, EndpointRange : 12 (40) - BC7 MODE2
			dst_blk.m_mode = 2;
			dst_blk.m_partition = g_bc7_3_astc2_common_partitions[unpacked_src_blk.m_common_pattern].m_bc73;

			const uint32_t common_pattern_k = g_bc7_3_astc2_common_partitions[unpacked_src_blk.m_common_pattern].k;

			for (uint32_t bc7_part = 0; bc7_part < 3; bc7_part++)
			{
				const uint32_t astc_part = bc7_convert_partition_index_3_to_2(bc7_part, common_pattern_k);

				for (uint32_t c = 0; c < 3; c++)
				{
					dst_blk.m_low[bc7_part].m_c[c] = (g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[c * 2 + 0 + astc_part * 6]].m_unquant * 31 + 127) / 255;
					dst_blk.m_high[bc7_part].m_c[c] = (g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[c * 2 + 1 + astc_part * 6]].m_unquant * 31 + 127) / 255;
				}
			}

			for (uint32_t i = 0; i < 16; i++)
				dst_blk.m_selectors[i] = unpacked_src_blk.m_astc.m_weights[i];

			break;
		}
		case UASTC_MODE_INDEX_SOLID_COLOR:
		{
			// Void-Extent: Solid Color RGBA (BC7 MODE5 or MODE6)
			const color32& solid_color = unpacked_src_blk.m_solid_color;

			uint32_t best_err0 = g_bc7_mode_6_optimal_endpoints[solid_color.r][0].m_error + g_bc7_mode_6_optimal_endpoints[solid_color.g][0].m_error +
				g_bc7_mode_6_optimal_endpoints[solid_color.b][0].m_error + g_bc7_mode_6_optimal_endpoints[solid_color.a][0].m_error;

			uint32_t best_err1 = g_bc7_mode_6_optimal_endpoints[solid_color.r][1].m_error + g_bc7_mode_6_optimal_endpoints[solid_color.g][1].m_error +
				g_bc7_mode_6_optimal_endpoints[solid_color.b][1].m_error + g_bc7_mode_6_optimal_endpoints[solid_color.a][1].m_error;

			if (best_err0 > 0 && best_err1 > 0)
			{
				dst_blk.m_mode = 5;

				for (uint32_t c = 0; c < 3; c++)
				{
					dst_blk.m_low[0].m_c[c] = g_bc7_mode_5_optimal_endpoints[solid_color.c[c]].m_lo;
					dst_blk.m_high[0].m_c[c] = g_bc7_mode_5_optimal_endpoints[solid_color.c[c]].m_hi;
				}

				memset(dst_blk.m_selectors, BC7ENC_MODE_5_OPTIMAL_INDEX, 16);

				dst_blk.m_low[0].m_c[3] = solid_color.c[3];
				dst_blk.m_high[0].m_c[3] = solid_color.c[3];

				//memset(dst_blk.m_alpha_selectors, 0, 16);
			}
			else
			{
				dst_blk.m_mode = 6;

				uint32_t best_p = 0;
				if (best_err1 < best_err0)
					best_p = 1;

				for (uint32_t c = 0; c < 4; c++)
				{
					dst_blk.m_low[0].m_c[c] = g_bc7_mode_6_optimal_endpoints[solid_color.c[c]][best_p].m_lo;
					dst_blk.m_high[0].m_c[c] = g_bc7_mode_6_optimal_endpoints[solid_color.c[c]][best_p].m_hi;
				}

				dst_blk.m_pbits[0][0] = best_p;
				dst_blk.m_pbits[0][1] = best_p;
				memset(dst_blk.m_selectors, BC7ENC_MODE_6_OPTIMAL_INDEX, 16);
			}

			break;
		}
		case 9:
		case 16:
		{
			// 9. DualPlane: 0, WeightRange : 2 (4), Subsets : 2, EndpointRange : 8 (16) - BC7 MODE7
			// 16. DualPlane: 0, WeightRange: 2 (4), Subsets: 2, CEM: 4 (LA Direct), EndpointRange: 20 (256) - BC7 MODE7

			dst_blk.m_mode = 7;
			dst_blk.m_partition = g_astc_bc7_common_partitions2[unpacked_src_blk.m_common_pattern].m_bc7;

			const bool invert_partition = g_astc_bc7_common_partitions2[unpacked_src_blk.m_common_pattern].m_invert;

			for (uint32_t astc_subset = 0; astc_subset < 2; astc_subset++)
			{
				float xl[4], xh[4];

				if (total_comps == 2)
				{
					xl[0] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[0 + astc_subset * 4]].m_unquant / 255.0f;
					xh[0] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[1 + astc_subset * 4]].m_unquant / 255.0f;

					xl[1] = xl[0];
					xh[1] = xh[0];

					xl[2] = xl[0];
					xh[2] = xh[0];

					xl[3] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[2 + astc_subset * 4]].m_unquant / 255.0f;
					xh[3] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[3 + astc_subset * 4]].m_unquant / 255.0f;
				}
				else
				{
					xl[0] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[0 + astc_subset * 8]].m_unquant / 255.0f;
					xl[1] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[2 + astc_subset * 8]].m_unquant / 255.0f;
					xl[2] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[4 + astc_subset * 8]].m_unquant / 255.0f;
					xl[3] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[6 + astc_subset * 8]].m_unquant / 255.0f;

					xh[0] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[1 + astc_subset * 8]].m_unquant / 255.0f;
					xh[1] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[3 + astc_subset * 8]].m_unquant / 255.0f;
					xh[2] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[5 + astc_subset * 8]].m_unquant / 255.0f;
					xh[3] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[7 + astc_subset * 8]].m_unquant / 255.0f;
				}

				uint32_t best_pbits[2] = { 0, 0 };
				color_quad_u8 bestMinColor, bestMaxColor;
				memset(&bestMinColor, 0, sizeof(bestMinColor));
				memset(&bestMaxColor, 0, sizeof(bestMaxColor));
				determine_unique_pbits(4, 5, xl, xh, bestMinColor, bestMaxColor, best_pbits);

				const uint32_t bc7_subset_index = invert_partition ? (1 - astc_subset) : astc_subset;

				dst_blk.m_low[bc7_subset_index] = bestMinColor;
				dst_blk.m_high[bc7_subset_index] = bestMaxColor;

				dst_blk.m_pbits[bc7_subset_index][0] = best_pbits[0];
				dst_blk.m_pbits[bc7_subset_index][1] = best_pbits[1];
			} // astc_subset

			for (uint32_t i = 0; i < 16; i++)
				dst_blk.m_selectors[i] = unpacked_src_blk.m_astc.m_weights[i];

			break;
		}
		default:
			return false;
		}

		return true;
	}

	bool transcode_uastc_to_bc7(const uastc_block& src_blk, bc7_optimization_results& dst_blk)
	{
		unpacked_uastc_block unpacked_src_blk;
		if (!unpack_uastc(src_blk, unpacked_src_blk, false, false))
			return false;

		return transcode_uastc_to_bc7(unpacked_src_blk, dst_blk);
	}

	bool transcode_uastc_to_bc7(const uastc_block& src_blk, void* pDst)
	{
		bc7_optimization_results temp;
		if (!transcode_uastc_to_bc7(src_blk, temp))
			return false;

		encode_bc7_block(pDst, &temp);
		return true;
	}

	color32 apply_etc1_bias(const color32 &block_color, uint32_t bias, uint32_t limit, uint32_t subblock)
	{
		color32 result;

		for (uint32_t c = 0; c < 3; c++)
		{
			static const int s_divs[3] = { 1, 3, 9 };

			int delta = 0;

			switch (bias)
			{
			case 2: delta = subblock ? 0 : ((c == 0) ? -1 : 0); break;
			case 5: delta = subblock ? 0 : ((c == 1) ? -1 : 0); break;
			case 6: delta = subblock ? 0 : ((c == 2) ? -1 : 0); break;

			case 7: delta = subblock ? 0 : ((c == 0) ? 1 : 0); break;
			case 11: delta = subblock ? 0 : ((c == 1) ? 1 : 0); break;
			case 15: delta = subblock ? 0 : ((c == 2) ? 1 : 0); break;

			case 18: delta = subblock ? ((c == 0) ? -1 : 0) : 0; break;
			case 19: delta = subblock ? ((c == 1) ? -1 : 0) : 0; break;
			case 20: delta = subblock ? ((c == 2) ? -1 : 0) : 0; break;

			case 21: delta = subblock ? ((c == 0) ? 1 : 0) : 0; break;
			case 24: delta = subblock ? ((c == 1) ? 1 : 0) : 0; break;
			case 8: delta = subblock ? ((c == 2) ? 1 : 0) : 0; break;

			case 10: delta = -2; break;

			case 27: delta = subblock ? 0 : -1; break;
			case 28: delta = subblock ? -1 : 1; break;
			case 29: delta = subblock ? 1 : 0; break;
			case 30: delta = subblock ? -1 : 0; break;
			case 31: delta = subblock ? 0 : 1; break;

			default:
				delta = ((bias / s_divs[c]) % 3) - 1;
				break;
			}

			int v = block_color[c];
			if (v == 0)
			{
				if (delta == -2)
					v += 3;
				else
					v += delta + 1;
			}
			else if (v == (int)limit)
			{
				v += (delta - 1);
			}
			else
			{
				v += delta;
				if ((v < 0) || (v > (int)limit))
					v = (v - delta) - delta;
			}

			assert(v >= 0);
			assert(v <= (int)limit);

			result[c] = (uint8_t)v;
		}

		return result;
	}

	static void etc1_determine_selectors(decoder_etc_block& dst_blk, const color32* pSource_pixels, uint32_t first_subblock, uint32_t last_subblock)
	{
		static const uint8_t s_tran[4] = { 1, 0, 2, 3 };

		uint16_t l_bitmask = 0;
		uint16_t h_bitmask = 0;

		for (uint32_t subblock = first_subblock; subblock < last_subblock; subblock++)
		{
			color32 block_colors[4];
			dst_blk.get_block_colors(block_colors, subblock);

			uint32_t block_y[4];
			for (uint32_t i = 0; i < 4; i++)
				block_y[i] = block_colors[i][0] * 54 + block_colors[i][1] * 183 + block_colors[i][2] * 19;

			const uint32_t block_y01 = block_y[0] + block_y[1];
			const uint32_t block_y12 = block_y[1] + block_y[2];
			const uint32_t block_y23 = block_y[2] + block_y[3];

			// X0 X0 X0 X0 X1 X1 X1 X1 X2 X2 X2 X2 X3 X3 X3 X3
			// Y0 Y1 Y2 Y3 Y0 Y1 Y2 Y3 Y0 Y1 Y2 Y3 Y0 Y1 Y2 Y3

			if (dst_blk.get_flip_bit())
			{
				uint32_t ofs = subblock * 2;

				for (uint32_t y = 0; y < 2; y++)
				{
					for (uint32_t x = 0; x < 4; x++)
					{
						const color32& c = pSource_pixels[x + (subblock * 2 + y) * 4];
						const uint32_t l = c[0] * 108 + c[1] * 366 + c[2] * 38;

						uint32_t t = s_tran[(l < block_y01) + (l < block_y12) + (l < block_y23)];

						assert(ofs < 16);
						l_bitmask |= ((t & 1) << ofs);
						h_bitmask |= ((t >> 1) << ofs);
						ofs += 4;
					}

					ofs = (int)ofs + 1 - 4 * 4;
				}
			}
			else
			{
				uint32_t ofs = (subblock * 2) * 4;
				for (uint32_t x = 0; x < 2; x++)
				{
					for (uint32_t y = 0; y < 4; y++)
					{
						const color32& c = pSource_pixels[subblock * 2 + x + y * 4];
						const uint32_t l = c[0] * 108 + c[1] * 366 + c[2] * 38;

						uint32_t t = s_tran[(l < block_y01) + (l < block_y12) + (l < block_y23)];

						assert(ofs < 16);
						l_bitmask |= ((t & 1) << ofs);
						h_bitmask |= ((t >> 1) << ofs);
						++ofs;
					}
				}
			}
		}

		dst_blk.m_bytes[7] = (uint8_t)(l_bitmask);
		dst_blk.m_bytes[6] = (uint8_t)(l_bitmask >> 8);
		dst_blk.m_bytes[5] = (uint8_t)(h_bitmask);
		dst_blk.m_bytes[4] = (uint8_t)(h_bitmask >> 8);
	}

	static const uint8_t s_etc1_solid_selectors[4][4] = { { 255, 255, 255, 255 }, { 255, 255, 0, 0 }, { 0, 0, 0, 0 }, {0, 0, 255, 255 } };

	struct etc_coord2
	{
		uint8_t m_x, m_y;
	};

	// [flip][subblock][pixel_index]
	const etc_coord2 g_etc1_pixel_coords[2][2][8] =
	{
		{
		  {
			 { 0, 0 }, { 0, 1 }, { 0, 2 }, { 0, 3 },
			 { 1, 0 }, { 1, 1 }, { 1, 2 }, { 1, 3 }
		  },
		  {
			 { 2, 0 }, { 2, 1 }, { 2, 2 }, { 2, 3 },
			 { 3, 0 }, { 3, 1 }, { 3, 2 }, { 3, 3 }
		  }
		},
		{
		  {
			 { 0, 0 }, { 1, 0 }, { 2, 0 }, { 3, 0 },
			 { 0, 1 }, { 1, 1 }, { 2, 1 }, { 3, 1 }
		  },
		  {
			 { 0, 2 }, { 1, 2 }, { 2, 2 }, { 3, 2 },
			 { 0, 3 }, { 1, 3 }, { 2, 3 }, { 3, 3 }
		  },
		}
	};

	void transcode_uastc_to_etc1(unpacked_uastc_block& unpacked_src_blk, color32 block_pixels[4][4], void* pDst)
	{
		decoder_etc_block& dst_blk = *static_cast<decoder_etc_block*>(pDst);

		if (unpacked_src_blk.m_mode == UASTC_MODE_INDEX_SOLID_COLOR)
		{
			dst_blk.m_bytes[3] = (uint8_t)((unpacked_src_blk.m_etc1_diff << 1) | (unpacked_src_blk.m_etc1_inten0 << 5) | (unpacked_src_blk.m_etc1_inten0 << 2));

			if (unpacked_src_blk.m_etc1_diff)
			{
				dst_blk.m_bytes[0] = (uint8_t)(unpacked_src_blk.m_etc1_r << 3);
				dst_blk.m_bytes[1] = (uint8_t)(unpacked_src_blk.m_etc1_g << 3);
				dst_blk.m_bytes[2] = (uint8_t)(unpacked_src_blk.m_etc1_b << 3);
			}
			else
			{
				dst_blk.m_bytes[0] = (uint8_t)(unpacked_src_blk.m_etc1_r | (unpacked_src_blk.m_etc1_r << 4));
				dst_blk.m_bytes[1] = (uint8_t)(unpacked_src_blk.m_etc1_g | (unpacked_src_blk.m_etc1_g << 4));
				dst_blk.m_bytes[2] = (uint8_t)(unpacked_src_blk.m_etc1_b | (unpacked_src_blk.m_etc1_b << 4));
			}

			memcpy(dst_blk.m_bytes + 4, &s_etc1_solid_selectors[unpacked_src_blk.m_etc1_selector][0], 4);

			return;
		}

		const bool flip = unpacked_src_blk.m_etc1_flip != 0;
		const bool diff = unpacked_src_blk.m_etc1_diff != 0;

		dst_blk.m_bytes[3] = (uint8_t)((int)flip | (diff << 1) | (unpacked_src_blk.m_etc1_inten0 << 5) | (unpacked_src_blk.m_etc1_inten1 << 2));

		const uint32_t limit = diff ? 31 : 15;

		color32 block_colors[2];

		for (uint32_t subset = 0; subset < 2; subset++)
		{
			uint32_t avg_color[3];
			memset(avg_color, 0, sizeof(avg_color));

			for (uint32_t j = 0; j < 8; j++)
			{
				const etc_coord2& c = g_etc1_pixel_coords[flip][subset][j];

				avg_color[0] += block_pixels[c.m_y][c.m_x].r;
				avg_color[1] += block_pixels[c.m_y][c.m_x].g;
				avg_color[2] += block_pixels[c.m_y][c.m_x].b;
			} // j

			block_colors[subset][0] = (uint8_t)((avg_color[0] * limit + 1020) / (8 * 255));
			block_colors[subset][1] = (uint8_t)((avg_color[1] * limit + 1020) / (8 * 255));
			block_colors[subset][2] = (uint8_t)((avg_color[2] * limit + 1020) / (8 * 255));
			block_colors[subset][3] = 0;

			if (g_uastc_mode_has_etc1_bias[unpacked_src_blk.m_mode])
			{
				block_colors[subset] = apply_etc1_bias(block_colors[subset], unpacked_src_blk.m_etc1_bias, limit, subset);
			}

		} // subset

		if (diff)
		{
			int dr = block_colors[1].r - block_colors[0].r;
			int dg = block_colors[1].g - block_colors[0].g;
			int db = block_colors[1].b - block_colors[0].b;

			dr = basisu::clamp<int>(dr, cETC1ColorDeltaMin, cETC1ColorDeltaMax);
			dg = basisu::clamp<int>(dg, cETC1ColorDeltaMin, cETC1ColorDeltaMax);
			db = basisu::clamp<int>(db, cETC1ColorDeltaMin, cETC1ColorDeltaMax);

			if (dr < 0) dr += 8;
			if (dg < 0) dg += 8;
			if (db < 0) db += 8;

			dst_blk.m_bytes[0] = (uint8_t)((block_colors[0].r << 3) | dr);
			dst_blk.m_bytes[1] = (uint8_t)((block_colors[0].g << 3) | dg);
			dst_blk.m_bytes[2] = (uint8_t)((block_colors[0].b << 3) | db);
		}
		else
		{
			dst_blk.m_bytes[0] = (uint8_t)(block_colors[1].r | (block_colors[0].r << 4));
			dst_blk.m_bytes[1] = (uint8_t)(block_colors[1].g | (block_colors[0].g << 4));
			dst_blk.m_bytes[2] = (uint8_t)(block_colors[1].b | (block_colors[0].b << 4));
		}

		etc1_determine_selectors(dst_blk, &block_pixels[0][0], 0, 2);
	}

	bool transcode_uastc_to_etc1(const uastc_block& src_blk, void* pDst)
	{
		unpacked_uastc_block unpacked_src_blk;
		if (!unpack_uastc(src_blk, unpacked_src_blk, false))
			return false;

		color32 block_pixels[4][4];
		if (unpacked_src_blk.m_mode != UASTC_MODE_INDEX_SOLID_COLOR)
		{
			const bool unpack_srgb = false;
			if (!unpack_uastc(unpacked_src_blk, &block_pixels[0][0], unpack_srgb))
				return false;
		}

		transcode_uastc_to_etc1(unpacked_src_blk, block_pixels, pDst);

		return true;
	}

	static inline int gray_distance2(const uint8_t c, int y)
	{
		int gray_dist = (int)c - y;
		return gray_dist * gray_dist;
	}

	static bool pack_etc1_y_estimate_flipped(const uint8_t* pSrc_pixels,
		int& upper_avg, int& lower_avg, int& left_avg, int& right_avg)
	{
		int sums[2][2];

#define GET_XY(x, y) pSrc_pixels[(x) + ((y) * 4)]

		sums[0][0] = GET_XY(0, 0) + GET_XY(0, 1) + GET_XY(1, 0) + GET_XY(1, 1);
		sums[1][0] = GET_XY(2, 0) + GET_XY(2, 1) + GET_XY(3, 0) + GET_XY(3, 1);
		sums[0][1] = GET_XY(0, 2) + GET_XY(0, 3) + GET_XY(1, 2) + GET_XY(1, 3);
		sums[1][1] = GET_XY(2, 2) + GET_XY(2, 3) + GET_XY(3, 2) + GET_XY(3, 3);

		upper_avg = (sums[0][0] + sums[1][0] + 4) / 8;
		lower_avg = (sums[0][1] + sums[1][1] + 4) / 8;
		left_avg = (sums[0][0] + sums[0][1] + 4) / 8;
		right_avg = (sums[1][0] + sums[1][1] + 4) / 8;

#undef GET_XY
#define GET_XY(x, y, a) gray_distance2(pSrc_pixels[(x) + ((y) * 4)], a)

		int upper_gray_dist = 0, lower_gray_dist = 0, left_gray_dist = 0, right_gray_dist = 0;
		for (uint32_t i = 0; i < 4; i++)
		{
			for (uint32_t j = 0; j < 2; j++)
			{
				upper_gray_dist += GET_XY(i, j, upper_avg);
				lower_gray_dist += GET_XY(i, 2 + j, lower_avg);
				left_gray_dist += GET_XY(j, i, left_avg);
				right_gray_dist += GET_XY(2 + j, i, right_avg);
			}
		}

#undef GET_XY

		int upper_lower_sum = upper_gray_dist + lower_gray_dist;
		int left_right_sum = left_gray_dist + right_gray_dist;

		return upper_lower_sum < left_right_sum;
	}

	// Base  Sel Table
	// XXXXX XX  XXX
	static const uint16_t g_etc1_y_solid_block_configs[256] =
	{
		0,781,64,161,260,192,33,131,96,320,65,162,261,193,34,291,97,224,66,163,262,194,35,549,98,4,67,653,164,195,523,36,99,5,578,68,165,353,196,37,135,100,324,69,166,354,197,38,295,101,228,70,167,
		355,198,39,553,102,8,71,608,168,199,527,40,103,9,582,72,169,357,200,41,139,104,328,73,170,358,201,42,299,105,232,74,171,359,202,43,557,106,12,75,612,172,203,531,44,107,13,586,76,173,361,
		204,45,143,108,332,77,174,362,205,46,303,109,236,78,175,363,206,47,561,110,16,79,616,176,207,535,48,111,17,590,80,177,365,208,49,147,112,336,81,178,366,209,50,307,113,240,82,179,367,210,
		51,565,114,20,83,620,180,211,539,52,115,21,594,84,181,369,212,53,151,116,340,85,182,370,213,54,311,117,244,86,183,371,214,55,569,118,24,87,624,184,215,543,56,119,25,598,88,185,373,216,57,
		155,120,344,89,186,374,217,58,315,121,248,90,187,375,218,59,573,122,28,91,628,188,219,754,60,123,29,602,92,189,377,220,61,159,124,348,93,190,378,221,62,319,125,252,94,191,379,222,63,882,126
	};

	// individual
	// table base sel0 sel1 sel2 sel3
	static const uint16_t g_etc1_y_solid_block_4i_configs[256] =
	{
		0xA000,0xA800,0x540B,0xAA01,0xAA01,0xFE00,0xFF00,0xFF00,0x8,0x5515,0x5509,0x5509,0xAA03,0x5508,0x5508,0x9508,0xA508,0xA908,0xAA08,0x5513,0xAA09,0xAA09,0xAA05,0xFF08,0xFF08,0x10,0x551D,0x5511,0x5511,
		0xAA0B,0x5510,0x5510,0x9510,0xA510,0xA910,0xAA10,0x551B,0xAA11,0xAA11,0xAA0D,0xFF10,0xFF10,0x18,0x5525,0x5519,0x5519,0xAA13,0x5518,0x5518,0x9518,0xA518,0xA918,0xAA18,0x5523,0xAA19,0xAA19,0xAA15,
		0xFF18,0xFF18,0x20,0x552D,0x5521,0x5521,0xAA1B,0x5520,0x5520,0x9520,0xA520,0xA920,0xAA20,0x552B,0xAA21,0xAA21,0xAA1D,0xFF20,0xFF20,0x28,0x5535,0x5529,0x5529,0xAA23,0x5528,0x5528,0x9528,0xA528,0xA928,
		0xAA28,0x5533,0xAA29,0xAA29,0xAA25,0xFF28,0xFF28,0x30,0x553D,0x5531,0x5531,0xAA2B,0x5530,0x5530,0x9530,0xA530,0xA930,0xAA30,0x553B,0xAA31,0xAA31,0xAA2D,0xFF30,0xFF30,0x38,0x5545,0x5539,0x5539,0xAA33,
		0x5538,0x5538,0x9538,0xA538,0xA938,0xAA38,0x5543,0xAA39,0xAA39,0xAA35,0xFF38,0xFF38,0x40,0x554D,0x5541,0x5541,0xAA3B,0x5540,0x5540,0x9540,0xA540,0xA940,0xAA40,0x554B,0xAA41,0xAA41,0xAA3D,0xFF40,0xFF40,
		0x48,0x5555,0x5549,0x5549,0xAA43,0x5548,0x5548,0x9548,0xA548,0xA948,0xAA48,0x5553,0xAA49,0xAA49,0xAA45,0xFF48,0xFF48,0x50,0x555D,0x5551,0x5551,0xAA4B,0x5550,0x5550,0x9550,0xA550,0xA950,0xAA50,0x555B,
		0xAA51,0xAA51,0xAA4D,0xFF50,0xFF50,0x58,0x5565,0x5559,0x5559,0xAA53,0x5558,0x5558,0x9558,0xA558,0xA958,0xAA58,0x5563,0xAA59,0xAA59,0xAA55,0xFF58,0xFF58,0x60,0x556D,0x5561,0x5561,0xAA5B,0x5560,0x5560,
		0x9560,0xA560,0xA960,0xAA60,0x556B,0xAA61,0xAA61,0xAA5D,0xFF60,0xFF60,0x68,0x5575,0x5569,0x5569,0xAA63,0x5568,0x5568,0x9568,0xA568,0xA968,0xAA68,0x5573,0xAA69,0xAA69,0xAA65,0xFF68,0xFF68,0x70,0x557D,
		0x5571,0x5571,0xAA6B,0x5570,0x5570,0x9570,0xA570,0xA970,0xAA70,0x557B,0xAA71,0xAA71,0xAA6D,0xFF70,0xFF70,0x78,0x78,0x5579,0x5579,0xAA73,0x5578,0x9578,0x2578,0xE6E,0x278
	};

	static const uint16_t g_etc1_y_solid_block_2i_configs[256] =
	{
		0x416,0x800,0xA00,0x50B,0xA01,0xA01,0xF00,0xF00,0xF00,0x8,0x515,0x509,0x509,0xA03,0x508,0x508,0xF01,0xF01,0xA08,0xA08,0x513,0xA09,0xA09,0xA05,0xF08,0xF08,0x10,0x51D,0x511,0x511,0xA0B,0x510,0x510,0xF09,
		0xF09,0xA10,0xA10,0x51B,0xA11,0xA11,0xA0D,0xF10,0xF10,0x18,0x525,0x519,0x519,0xA13,0x518,0x518,0xF11,0xF11,0xA18,0xA18,0x523,0xA19,0xA19,0xA15,0xF18,0xF18,0x20,0x52D,0x521,0x521,0xA1B,0x520,0x520,0xF19,
		0xF19,0xA20,0xA20,0x52B,0xA21,0xA21,0xA1D,0xF20,0xF20,0x28,0x535,0x529,0x529,0xA23,0x528,0x528,0xF21,0xF21,0xA28,0xA28,0x533,0xA29,0xA29,0xA25,0xF28,0xF28,0x30,0x53D,0x531,0x531,0xA2B,0x530,0x530,0xF29,
		0xF29,0xA30,0xA30,0x53B,0xA31,0xA31,0xA2D,0xF30,0xF30,0x38,0x545,0x539,0x539,0xA33,0x538,0x538,0xF31,0xF31,0xA38,0xA38,0x543,0xA39,0xA39,0xA35,0xF38,0xF38,0x40,0x54D,0x541,0x541,0xA3B,0x540,0x540,0xF39,
		0xF39,0xA40,0xA40,0x54B,0xA41,0xA41,0xA3D,0xF40,0xF40,0x48,0x555,0x549,0x549,0xA43,0x548,0x548,0xF41,0xF41,0xA48,0xA48,0x553,0xA49,0xA49,0xA45,0xF48,0xF48,0x50,0x55D,0x551,0x551,0xA4B,0x550,0x550,0xF49,
		0xF49,0xA50,0xA50,0x55B,0xA51,0xA51,0xA4D,0xF50,0xF50,0x58,0x565,0x559,0x559,0xA53,0x558,0x558,0xF51,0xF51,0xA58,0xA58,0x563,0xA59,0xA59,0xA55,0xF58,0xF58,0x60,0x56D,0x561,0x561,0xA5B,0x560,0x560,0xF59,
		0xF59,0xA60,0xA60,0x56B,0xA61,0xA61,0xA5D,0xF60,0xF60,0x68,0x575,0x569,0x569,0xA63,0x568,0x568,0xF61,0xF61,0xA68,0xA68,0x573,0xA69,0xA69,0xA65,0xF68,0xF68,0x70,0x57D,0x571,0x571,0xA6B,0x570,0x570,0xF69,
		0xF69,0xA70,0xA70,0x57B,0xA71,0xA71,0xA6D,0xF70,0xF70,0x78,0x78,0x579,0x579,0xA73,0x578,0x578,0xE6E,0x278
	};

	static const uint16_t g_etc1_y_solid_block_1i_configs[256] =
	{
		0x0,0x116,0x200,0x200,0x10B,0x201,0x201,0x300,0x300,0x8,0x115,0x109,0x109,0x203,0x108,0x108,0x114,0x301,0x204,0x208,0x208,0x113,0x209,0x209,0x205,0x308,0x10,0x11D,0x111,0x111,0x20B,0x110,0x110,0x11C,0x309,
		0x20C,0x210,0x210,0x11B,0x211,0x211,0x20D,0x310,0x18,0x125,0x119,0x119,0x213,0x118,0x118,0x124,0x311,0x214,0x218,0x218,0x123,0x219,0x219,0x215,0x318,0x20,0x12D,0x121,0x121,0x21B,0x120,0x120,0x12C,0x319,0x21C,
		0x220,0x220,0x12B,0x221,0x221,0x21D,0x320,0x28,0x135,0x129,0x129,0x223,0x128,0x128,0x134,0x321,0x224,0x228,0x228,0x133,0x229,0x229,0x225,0x328,0x30,0x13D,0x131,0x131,0x22B,0x130,0x130,0x13C,0x329,0x22C,0x230,
		0x230,0x13B,0x231,0x231,0x22D,0x330,0x38,0x145,0x139,0x139,0x233,0x138,0x138,0x144,0x331,0x234,0x238,0x238,0x143,0x239,0x239,0x235,0x338,0x40,0x14D,0x141,0x141,0x23B,0x140,0x140,0x14C,0x339,0x23C,0x240,0x240,
		0x14B,0x241,0x241,0x23D,0x340,0x48,0x155,0x149,0x149,0x243,0x148,0x148,0x154,0x341,0x244,0x248,0x248,0x153,0x249,0x249,0x245,0x348,0x50,0x15D,0x151,0x151,0x24B,0x150,0x150,0x15C,0x349,0x24C,0x250,0x250,0x15B,
		0x251,0x251,0x24D,0x350,0x58,0x165,0x159,0x159,0x253,0x158,0x158,0x164,0x351,0x254,0x258,0x258,0x163,0x259,0x259,0x255,0x358,0x60,0x16D,0x161,0x161,0x25B,0x160,0x160,0x16C,0x359,0x25C,0x260,0x260,0x16B,0x261,
		0x261,0x25D,0x360,0x68,0x175,0x169,0x169,0x263,0x168,0x168,0x174,0x361,0x264,0x268,0x268,0x173,0x269,0x269,0x265,0x368,0x70,0x17D,0x171,0x171,0x26B,0x170,0x170,0x17C,0x369,0x26C,0x270,0x270,0x17B,0x271,0x271,
		0x26D,0x370,0x78,0x78,0x179,0x179,0x273,0x178,0x178,0x26E,0x278
	};

	// We don't have any useful hints to accelerate single channel ETC1, so we need to real-time encode from scratch.
	bool transcode_uastc_to_etc1(const uastc_block& src_blk, void* pDst, uint32_t channel)
	{
		unpacked_uastc_block unpacked_src_blk;
		if (!unpack_uastc(src_blk, unpacked_src_blk, false))
			return false;

#if 0
		for (uint32_t individ = 0; individ < 2; individ++)
		{
			uint32_t overall_error = 0;

			for (uint32_t c = 0; c < 256; c++)
			{
				uint32_t best_err = UINT32_MAX;
				uint32_t best_individ = 0;
				uint32_t best_base = 0;
				uint32_t best_sels[4] = { 0,0,0,0 };
				uint32_t best_table = 0;

				const uint32_t limit = individ ? 16 : 32;

				for (uint32_t table = 0; table < 8; table++)
				{
					for (uint32_t base = 0; base < limit; base++)
					{
						uint32_t total_e = 0;
						uint32_t sels[4] = { 0,0,0,0 };

						const uint32_t N = 4;
						for (uint32_t i = 0; i < basisu::minimum<uint32_t>(N, (256 - c)); i++)
						{
							uint32_t best_sel_e = UINT32_MAX;
							uint32_t best_sel = 0;

							for (uint32_t sel = 0; sel < 4; sel++)
							{
								int val = individ ? ((base << 4) | base) : ((base << 3) | (base >> 2));
								val = clamp255(val + g_etc1_inten_tables[table][sel]);

								int e = iabs(val - clamp255(c + i));
								if (e < best_sel_e)
								{
									best_sel_e = e;
									best_sel = sel;
								}

							} // sel

							sels[i] = best_sel;
							total_e += best_sel_e * best_sel_e;

						} // i

						if (total_e < best_err)
						{
							best_err = total_e;
							best_individ = individ;
							best_base = base;
							memcpy(best_sels, sels, sizeof(best_sels));
							best_table = table;
						}

					} // base
				} // table

				//printf("%u: %u,%u,%u,%u,%u,%u,%u,%u\n", c, best_err, best_individ, best_table, best_base, best_sels[0], best_sels[1], best_sels[2], best_sels[3]);

				uint32_t encoded = best_table | (best_base << 3) |
					(best_sels[0] << 8) |
					(best_sels[1] << 10) |
					(best_sels[2] << 12) |
					(best_sels[3] << 14);

				printf("0x%X,", encoded);

				overall_error += best_err;
			} // c

			printf("\n");
			printf("Overall error: %u\n", overall_error);

		} // individ

		exit(0);
#endif

#if 0
		for (uint32_t individ = 0; individ < 2; individ++)
		{
			uint32_t overall_error = 0;

			for (uint32_t c = 0; c < 256; c++)
			{
				uint32_t best_err = UINT32_MAX;
				uint32_t best_individ = 0;
				uint32_t best_base = 0;
				uint32_t best_sels[4] = { 0,0,0,0 };
				uint32_t best_table = 0;

				const uint32_t limit = individ ? 16 : 32;

				for (uint32_t table = 0; table < 8; table++)
				{
					for (uint32_t base = 0; base < limit; base++)
					{
						uint32_t total_e = 0;
						uint32_t sels[4] = { 0,0,0,0 };

						const uint32_t N = 1;
						for (uint32_t i = 0; i < basisu::minimum<uint32_t>(N, (256 - c)); i++)
						{
							uint32_t best_sel_e = UINT32_MAX;
							uint32_t best_sel = 0;

							for (uint32_t sel = 0; sel < 4; sel++)
							{
								int val = individ ? ((base << 4) | base) : ((base << 3) | (base >> 2));
								val = clamp255(val + g_etc1_inten_tables[table][sel]);

								int e = iabs(val - clamp255(c + i));
								if (e < best_sel_e)
								{
									best_sel_e = e;
									best_sel = sel;
								}

							} // sel

							sels[i] = best_sel;
							total_e += best_sel_e * best_sel_e;

						} // i

						if (total_e < best_err)
						{
							best_err = total_e;
							best_individ = individ;
							best_base = base;
							memcpy(best_sels, sels, sizeof(best_sels));
							best_table = table;
						}

					} // base
				} // table

				//printf("%u: %u,%u,%u,%u,%u,%u,%u,%u\n", c, best_err, best_individ, best_table, best_base, best_sels[0], best_sels[1], best_sels[2], best_sels[3]);

				uint32_t encoded = best_table | (best_base << 3) |
					(best_sels[0] << 8) |
					(best_sels[1] << 10) |
					(best_sels[2] << 12) |
					(best_sels[3] << 14);

				printf("0x%X,", encoded);

				overall_error += best_err;
			} // c

			printf("\n");
			printf("Overall error: %u\n", overall_error);

		} // individ

		exit(0);
#endif

		decoder_etc_block& dst_blk = *static_cast<decoder_etc_block*>(pDst);

		if (unpacked_src_blk.m_mode == UASTC_MODE_INDEX_SOLID_COLOR)
		{
			const uint32_t y = unpacked_src_blk.m_solid_color[channel];
			const uint32_t encoded_config = g_etc1_y_solid_block_configs[y];

			const uint32_t base = encoded_config & 31;
			const uint32_t sel = (encoded_config >> 5) & 3;
			const uint32_t table = encoded_config >> 7;

			dst_blk.m_bytes[3] = (uint8_t)(2 | (table << 5) | (table << 2));

			dst_blk.m_bytes[0] = (uint8_t)(base << 3);
			dst_blk.m_bytes[1] = (uint8_t)(base << 3);
			dst_blk.m_bytes[2] = (uint8_t)(base << 3);

			memcpy(dst_blk.m_bytes + 4, &s_etc1_solid_selectors[sel][0], 4);
			return true;
		}

		color32 block_pixels[4][4];
		const bool unpack_srgb = false;
		if (!unpack_uastc(unpacked_src_blk, &block_pixels[0][0], unpack_srgb))
			return false;

		uint8_t block_y[4][4];
		for (uint32_t i = 0; i < 16; i++)
			((uint8_t*)block_y)[i] = ((color32*)block_pixels)[i][channel];

		int upper_avg, lower_avg, left_avg, right_avg;
		bool flip = pack_etc1_y_estimate_flipped(&block_y[0][0], upper_avg, lower_avg, left_avg, right_avg);

		// non-flipped: | |
		// vs. 
		// flipped:     --
		//              --

		uint32_t low[2] = { 255, 255 }, high[2] = { 0, 0 };

		if (flip)
		{
			for (uint32_t y = 0; y < 2; y++)
			{
				for (uint32_t x = 0; x < 4; x++)
				{
					const uint32_t v = block_y[y][x];
					low[0] = basisu::minimum(low[0], v);
					high[0] = basisu::maximum(high[0], v);
				}
			}
			for (uint32_t y = 2; y < 4; y++)
			{
				for (uint32_t x = 0; x < 4; x++)
				{
					const uint32_t v = block_y[y][x];
					low[1] = basisu::minimum(low[1], v);
					high[1] = basisu::maximum(high[1], v);
				}
			}
		}
		else
		{
			for (uint32_t y = 0; y < 4; y++)
			{
				for (uint32_t x = 0; x < 2; x++)
				{
					const uint32_t v = block_y[y][x];
					low[0] = basisu::minimum(low[0], v);
					high[0] = basisu::maximum(high[0], v);
				}
			}
			for (uint32_t y = 0; y < 4; y++)
			{
				for (uint32_t x = 2; x < 4; x++)
				{
					const uint32_t v = block_y[y][x];
					low[1] = basisu::minimum(low[1], v);
					high[1] = basisu::maximum(high[1], v);
				}
			}
		}

		const uint32_t range[2] = { high[0] - low[0], high[1] - low[1] };

		dst_blk.m_bytes[3] = (uint8_t)((int)flip);

		if ((range[0] <= 3) && (range[1] <= 3))
		{
			// This is primarily for better gradients.
			dst_blk.m_bytes[0] = 0;
			dst_blk.m_bytes[1] = 0;
			dst_blk.m_bytes[2] = 0;

			uint16_t l_bitmask = 0, h_bitmask = 0;

			for (uint32_t subblock = 0; subblock < 2; subblock++)
			{
				const uint32_t encoded = (range[subblock] == 0) ? g_etc1_y_solid_block_1i_configs[low[subblock]] : ((range[subblock] < 2) ? g_etc1_y_solid_block_2i_configs[low[subblock]] : g_etc1_y_solid_block_4i_configs[low[subblock]]);

				const uint32_t table = encoded & 7;
				const uint32_t base = (encoded >> 3) & 31;
				assert(base <= 15);
				const uint32_t sels[4] = { (encoded >> 8) & 3, (encoded >> 10) & 3, (encoded >> 12) & 3, (encoded >> 14) & 3 };

				dst_blk.m_bytes[3] |= (uint8_t)(table << (subblock ? 2 : 5));

				const uint32_t sv = base << (subblock ? 0 : 4);
				dst_blk.m_bytes[0] |= (uint8_t)(sv);
				dst_blk.m_bytes[1] |= (uint8_t)(sv);
				dst_blk.m_bytes[2] |= (uint8_t)(sv);

				if (flip)
				{
					uint32_t ofs = subblock * 2;
					for (uint32_t y = 0; y < 2; y++)
					{
						for (uint32_t x = 0; x < 4; x++)
						{
							uint32_t t = block_y[y + subblock * 2][x];
							assert(t >= low[subblock] && t <= high[subblock]);
							t -= low[subblock];
							assert(t <= 3);

							t = g_selector_index_to_etc1[sels[t]];

							assert(ofs < 16);
							l_bitmask |= ((t & 1) << ofs);
							h_bitmask |= ((t >> 1) << ofs);
							ofs += 4;
						}

						ofs = (int)ofs + 1 - 4 * 4;
					}
				}
				else
				{
					uint32_t ofs = (subblock * 2) * 4;
					for (uint32_t x = 0; x < 2; x++)
					{
						for (uint32_t y = 0; y < 4; y++)
						{
							uint32_t t = block_y[y][x + subblock * 2];
							assert(t >= low[subblock] && t <= high[subblock]);
							t -= low[subblock];
							assert(t <= 3);

							t = g_selector_index_to_etc1[sels[t]];

							assert(ofs < 16);
							l_bitmask |= ((t & 1) << ofs);
							h_bitmask |= ((t >> 1) << ofs);
							++ofs;
						}
					}
				}
			} // subblock

			dst_blk.m_bytes[7] = (uint8_t)(l_bitmask);
			dst_blk.m_bytes[6] = (uint8_t)(l_bitmask >> 8);
			dst_blk.m_bytes[5] = (uint8_t)(h_bitmask);
			dst_blk.m_bytes[4] = (uint8_t)(h_bitmask >> 8);

			return true;
		}

		uint32_t y0 = ((flip ? upper_avg : left_avg) * 31 + 127) / 255;
		uint32_t y1 = ((flip ? lower_avg : right_avg) * 31 + 127) / 255;

		bool diff = true;

		int dy = y1 - y0;

		if ((dy < cETC1ColorDeltaMin) || (dy > cETC1ColorDeltaMax))
		{
			diff = false;

			y0 = ((flip ? upper_avg : left_avg) * 15 + 127) / 255;
			y1 = ((flip ? lower_avg : right_avg) * 15 + 127) / 255;

			dst_blk.m_bytes[0] = (uint8_t)(y1 | (y0 << 4));
			dst_blk.m_bytes[1] = (uint8_t)(y1 | (y0 << 4));
			dst_blk.m_bytes[2] = (uint8_t)(y1 | (y0 << 4));
		}
		else
		{
			dy = basisu::clamp<int>(dy, cETC1ColorDeltaMin, cETC1ColorDeltaMax);

			y1 = y0 + dy;

			if (dy < 0) dy += 8;

			dst_blk.m_bytes[0] = (uint8_t)((y0 << 3) | dy);
			dst_blk.m_bytes[1] = (uint8_t)((y0 << 3) | dy);
			dst_blk.m_bytes[2] = (uint8_t)((y0 << 3) | dy);

			dst_blk.m_bytes[3] |= 2;
		}

		const uint32_t base_y[2] = { diff ? ((y0 << 3) | (y0 >> 2)) : ((y0 << 4) | y0), diff ? ((y1 << 3) | (y1 >> 2)) : ((y1 << 4) | y1) };

		uint32_t enc_range[2];
		for (uint32_t subset = 0; subset < 2; subset++)
		{
			const int pos = basisu::iabs((int)high[subset] - (int)base_y[subset]);
			const int neg = basisu::iabs((int)base_y[subset] - (int)low[subset]);

			enc_range[subset] = basisu::maximum(pos, neg);
		}

		uint16_t l_bitmask = 0, h_bitmask = 0;
		for (uint32_t subblock = 0; subblock < 2; subblock++)
		{
			if ((!diff) && (range[subblock] <= 3))
			{
				const uint32_t encoded = (range[subblock] == 0) ? g_etc1_y_solid_block_1i_configs[low[subblock]] : ((range[subblock] < 2) ? g_etc1_y_solid_block_2i_configs[low[subblock]] : g_etc1_y_solid_block_4i_configs[low[subblock]]);

				const uint32_t table = encoded & 7;
				const uint32_t base = (encoded >> 3) & 31;
				assert(base <= 15);
				const uint32_t sels[4] = { (encoded >> 8) & 3, (encoded >> 10) & 3, (encoded >> 12) & 3, (encoded >> 14) & 3 };

				dst_blk.m_bytes[3] |= (uint8_t)(table << (subblock ? 2 : 5));

				const uint32_t mask = ~(0xF << (subblock ? 0 : 4));

				dst_blk.m_bytes[0] &= mask;
				dst_blk.m_bytes[1] &= mask;
				dst_blk.m_bytes[2] &= mask;

				const uint32_t sv = base << (subblock ? 0 : 4);
				dst_blk.m_bytes[0] |= (uint8_t)(sv);
				dst_blk.m_bytes[1] |= (uint8_t)(sv);
				dst_blk.m_bytes[2] |= (uint8_t)(sv);

				if (flip)
				{
					uint32_t ofs = subblock * 2;
					for (uint32_t y = 0; y < 2; y++)
					{
						for (uint32_t x = 0; x < 4; x++)
						{
							uint32_t t = block_y[y + subblock * 2][x];
							assert(t >= low[subblock] && t <= high[subblock]);
							t -= low[subblock];
							assert(t <= 3);

							t = g_selector_index_to_etc1[sels[t]];

							assert(ofs < 16);
							l_bitmask |= ((t & 1) << ofs);
							h_bitmask |= ((t >> 1) << ofs);
							ofs += 4;
						}

						ofs = (int)ofs + 1 - 4 * 4;
					}
				}
				else
				{
					uint32_t ofs = (subblock * 2) * 4;
					for (uint32_t x = 0; x < 2; x++)
					{
						for (uint32_t y = 0; y < 4; y++)
						{
							uint32_t t = block_y[y][x + subblock * 2];
							assert(t >= low[subblock] && t <= high[subblock]);
							t -= low[subblock];
							assert(t <= 3);

							t = g_selector_index_to_etc1[sels[t]];

							assert(ofs < 16);
							l_bitmask |= ((t & 1) << ofs);
							h_bitmask |= ((t >> 1) << ofs);
							++ofs;
						}
					}
				}

				continue;
			} // if

			uint32_t best_err = UINT32_MAX;
			uint8_t best_sels[8];
			uint32_t best_inten = 0;

			const int base = base_y[subblock];

			const int low_limit = -base;
			const int high_limit = 255 - base;

			assert(low_limit <= 0 && high_limit >= 0);

			uint32_t inten_table_mask = 0xFF;
			const uint32_t er = enc_range[subblock];
			// Each one of these tables is expensive to evaluate, so let's only examine the ones we know may be useful.
			if (er <= 51)
			{
				inten_table_mask = 0xF;

				if (er > 22)
					inten_table_mask &= ~(1 << 0);

				if ((er < 4) || (er > 39))
					inten_table_mask &= ~(1 << 1);

				if (er < 9)
					inten_table_mask &= ~(1 << 2);

				if (er < 12)
					inten_table_mask &= ~(1 << 3);
			}
			else
			{
				inten_table_mask &= ~((1 << 0) | (1 << 1));

				if (er > 60)
					inten_table_mask &= ~(1 << 2);

				if (er > 89)
					inten_table_mask &= ~(1 << 3);

				if (er > 120)
					inten_table_mask &= ~(1 << 4);

				if (er > 136)
					inten_table_mask &= ~(1 << 5);

				if (er > 174)
					inten_table_mask &= ~(1 << 6);
			}

			for (uint32_t inten = 0; inten < 8; inten++)
			{
				if ((inten_table_mask & (1 << inten)) == 0)
					continue;

				const int t0 = basisu::maximum(low_limit, g_etc1_inten_tables[inten][0]);
				const int t1 = basisu::maximum(low_limit, g_etc1_inten_tables[inten][1]);
				const int t2 = basisu::minimum(high_limit, g_etc1_inten_tables[inten][2]);
				const int t3 = basisu::minimum(high_limit, g_etc1_inten_tables[inten][3]);
				assert((t0 <= t1) && (t1 <= t2) && (t2 <= t3));

				const int tv[4] = { t2, t3, t1, t0 };

				const int thresh01 = t0 + t1;
				const int thresh12 = t1 + t2;
				const int thresh23 = t2 + t3;

				assert(thresh01 <= thresh12 && thresh12 <= thresh23);

				static const uint8_t s_table[4] = { 1, 0, 2, 3 };

				uint32_t total_err = 0;
				uint8_t sels[8];

				if (flip)
				{
					if (((int)high[subblock] - base) * 2 < thresh01)
					{
						memset(sels, 3, 8);

						for (uint32_t y = 0; y < 2; y++)
						{
							for (uint32_t x = 0; x < 4; x++)
							{
								const int delta = (int)block_y[y + subblock * 2][x] - base;

								const uint32_t c = 3;

								uint32_t e = basisu::iabs(tv[c] - delta);
								total_err += e * e;
							}
							if (total_err >= best_err)
								break;
						}
					}
					else if (((int)low[subblock] - base) * 2 >= thresh23)
					{
						memset(sels, 1, 8);

						for (uint32_t y = 0; y < 2; y++)
						{
							for (uint32_t x = 0; x < 4; x++)
							{
								const int delta = (int)block_y[y + subblock * 2][x] - base;

								const uint32_t c = 1;

								uint32_t e = basisu::iabs(tv[c] - delta);
								total_err += e * e;
							}
							if (total_err >= best_err)
								break;
						}
					}
					else
					{
						for (uint32_t y = 0; y < 2; y++)
						{
							for (uint32_t x = 0; x < 4; x++)
							{
								const int delta = (int)block_y[y + subblock * 2][x] - base;
								const int delta2 = delta * 2;

								uint32_t c = s_table[(delta2 < thresh01) + (delta2 < thresh12) + (delta2 < thresh23)];
								sels[y * 4 + x] = (uint8_t)c;

								uint32_t e = basisu::iabs(tv[c] - delta);
								total_err += e * e;
							}
							if (total_err >= best_err)
								break;
						}
					}
				}
				else
				{
					if (((int)high[subblock] - base) * 2 < thresh01)
					{
						memset(sels, 3, 8);

						for (uint32_t y = 0; y < 4; y++)
						{
							for (uint32_t x = 0; x < 2; x++)
							{
								const int delta = (int)block_y[y][x + subblock * 2] - base;

								const uint32_t c = 3;

								uint32_t e = basisu::iabs(tv[c] - delta);
								total_err += e * e;
							}
							if (total_err >= best_err)
								break;
						}
					}
					else if (((int)low[subblock] - base) * 2 >= thresh23)
					{
						memset(sels, 1, 8);

						for (uint32_t y = 0; y < 4; y++)
						{
							for (uint32_t x = 0; x < 2; x++)
							{
								const int delta = (int)block_y[y][x + subblock * 2] - base;

								const uint32_t c = 1;

								uint32_t e = basisu::iabs(tv[c] - delta);
								total_err += e * e;
							}
							if (total_err >= best_err)
								break;
						}
					}
					else
					{
						for (uint32_t y = 0; y < 4; y++)
						{
							for (uint32_t x = 0; x < 2; x++)
							{
								const int delta = (int)block_y[y][x + subblock * 2] - base;
								const int delta2 = delta * 2;

								uint32_t c = s_table[(delta2 < thresh01) + (delta2 < thresh12) + (delta2 < thresh23)];
								sels[y * 2 + x] = (uint8_t)c;

								uint32_t e = basisu::iabs(tv[c] - delta);
								total_err += e * e;
							}
							if (total_err >= best_err)
								break;
						}
					}
				}

				if (total_err < best_err)
				{
					best_err = total_err;
					best_inten = inten;
					memcpy(best_sels, sels, 8);
				}

			} // inten

			//g_inten_hist[best_inten][enc_range[subblock]]++;

			dst_blk.m_bytes[3] |= (uint8_t)(best_inten << (subblock ? 2 : 5));

			if (flip)
			{
				uint32_t ofs = subblock * 2;
				for (uint32_t y = 0; y < 2; y++)
				{
					for (uint32_t x = 0; x < 4; x++)
					{
						uint32_t t = best_sels[y * 4 + x];

						assert(ofs < 16);
						l_bitmask |= ((t & 1) << ofs);
						h_bitmask |= ((t >> 1) << ofs);
						ofs += 4;
					}

					ofs = (int)ofs + 1 - 4 * 4;
				}
			}
			else
			{
				uint32_t ofs = (subblock * 2) * 4;
				for (uint32_t x = 0; x < 2; x++)
				{
					for (uint32_t y = 0; y < 4; y++)
					{
						uint32_t t = best_sels[y * 2 + x];

						assert(ofs < 16);
						l_bitmask |= ((t & 1) << ofs);
						h_bitmask |= ((t >> 1) << ofs);
						++ofs;
					}
				}
			}

		} // subblock

		dst_blk.m_bytes[7] = (uint8_t)(l_bitmask);
		dst_blk.m_bytes[6] = (uint8_t)(l_bitmask >> 8);
		dst_blk.m_bytes[5] = (uint8_t)(h_bitmask);
		dst_blk.m_bytes[4] = (uint8_t)(h_bitmask >> 8);

		return true;
	}

	const uint32_t ETC2_EAC_MIN_VALUE_SELECTOR = 3, ETC2_EAC_MAX_VALUE_SELECTOR = 7;

	void transcode_uastc_to_etc2_eac_a8(unpacked_uastc_block& unpacked_src_blk, color32 block_pixels[4][4], void* pDst)
	{
		eac_block& dst = *static_cast<eac_block*>(pDst);
		const color32* pSrc_pixels = &block_pixels[0][0];

		if ((!g_uastc_mode_has_alpha[unpacked_src_blk.m_mode]) || (unpacked_src_blk.m_mode == UASTC_MODE_INDEX_SOLID_COLOR))
		{
			const uint32_t a = (unpacked_src_blk.m_mode == UASTC_MODE_INDEX_SOLID_COLOR) ? unpacked_src_blk.m_solid_color[3] : 255;

			dst.m_base = a;
			dst.m_table = 13;
			dst.m_multiplier = 1;

			memcpy(dst.m_selectors, g_etc2_eac_a8_sel4, sizeof(g_etc2_eac_a8_sel4));

			return;
		}

		uint32_t min_a = 255, max_a = 0;
		for (uint32_t i = 0; i < 16; i++)
		{
			min_a = basisu::minimum<uint32_t>(min_a, pSrc_pixels[i].a);
			max_a = basisu::maximum<uint32_t>(max_a, pSrc_pixels[i].a);
		}

		if (min_a == max_a)
		{
			dst.m_base = min_a;
			dst.m_table = 13;
			dst.m_multiplier = 1;

			memcpy(dst.m_selectors, g_etc2_eac_a8_sel4, sizeof(g_etc2_eac_a8_sel4));
			return;
		}

		const uint32_t table = unpacked_src_blk.m_etc2_hints & 0xF;
		const int multiplier = unpacked_src_blk.m_etc2_hints >> 4;

		assert(multiplier >= 1);

		dst.m_multiplier = multiplier;
		dst.m_table = table;

		const float range = (float)(g_eac_modifier_table[dst.m_table][ETC2_EAC_MAX_VALUE_SELECTOR] - g_eac_modifier_table[dst.m_table][ETC2_EAC_MIN_VALUE_SELECTOR]);
		const int center = (int)roundf(basisu::lerp((float)min_a, (float)max_a, (float)(0 - g_eac_modifier_table[dst.m_table][ETC2_EAC_MIN_VALUE_SELECTOR]) / range));

		dst.m_base = center;

		const int8_t* pTable = &g_eac_modifier_table[dst.m_table][0];

		uint32_t vals[8];
		for (uint32_t j = 0; j < 8; j++)
			vals[j] = clamp255(center + (pTable[j] * multiplier));

		uint64_t sels = 0;
		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t a = block_pixels[i & 3][i >> 2].a;

			const uint32_t err0 = (basisu::iabs(vals[0] - a) << 3) | 0;
			const uint32_t err1 = (basisu::iabs(vals[1] - a) << 3) | 1;
			const uint32_t err2 = (basisu::iabs(vals[2] - a) << 3) | 2;
			const uint32_t err3 = (basisu::iabs(vals[3] - a) << 3) | 3;
			const uint32_t err4 = (basisu::iabs(vals[4] - a) << 3) | 4;
			const uint32_t err5 = (basisu::iabs(vals[5] - a) << 3) | 5;
			const uint32_t err6 = (basisu::iabs(vals[6] - a) << 3) | 6;
			const uint32_t err7 = (basisu::iabs(vals[7] - a) << 3) | 7;

			const uint32_t min_err = basisu::minimum(basisu::minimum(basisu::minimum(basisu::minimum(basisu::minimum(basisu::minimum(err0, err1, err2), err3), err4), err5), err6), err7);

			const uint64_t best_index = min_err & 7;
			sels |= (best_index << (45 - i * 3));
		}

		dst.set_selector_bits(sels);
	}

	bool transcode_uastc_to_etc2_rgba(const uastc_block& src_blk, void* pDst)
	{
		eac_block& dst_etc2_eac_a8_blk = *static_cast<eac_block*>(pDst);
		decoder_etc_block& dst_etc1_blk = static_cast<decoder_etc_block*>(pDst)[1];

		unpacked_uastc_block unpacked_src_blk;
		if (!unpack_uastc(src_blk, unpacked_src_blk, false))
			return false;

		color32 block_pixels[4][4];
		if (unpacked_src_blk.m_mode != UASTC_MODE_INDEX_SOLID_COLOR)
		{
			const bool unpack_srgb = false;
			if (!unpack_uastc(unpacked_src_blk, &block_pixels[0][0], unpack_srgb))
				return false;
		}

		transcode_uastc_to_etc2_eac_a8(unpacked_src_blk, block_pixels, &dst_etc2_eac_a8_blk);

		transcode_uastc_to_etc1(unpacked_src_blk, block_pixels, &dst_etc1_blk);

		return true;
	}

	static const uint8_t s_uastc5_to_bc1[32] = { 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 1, 1, 1, 1, 1, 1 };
	static const uint8_t s_uastc4_to_bc1[16] = { 0, 0, 0, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 1, 1, 1 };
	static const uint8_t s_uastc3_to_bc1[8] = { 0, 0, 2, 2, 3, 3, 1, 1 };
	static const uint8_t s_uastc2_to_bc1[4] = { 0, 2, 3, 1 };
	static const uint8_t s_uastc1_to_bc1[2] = { 0, 1 };
	const uint8_t* s_uastc_to_bc1_weights[6] = { nullptr, s_uastc1_to_bc1, s_uastc2_to_bc1, s_uastc3_to_bc1, s_uastc4_to_bc1, s_uastc5_to_bc1 };
				
	void encode_bc4(void* pDst, const uint8_t* pPixels, uint32_t stride)
	{
		uint32_t min0_v, max0_v, min1_v, max1_v,min2_v, max2_v, min3_v, max3_v;

		{
			min0_v = max0_v = pPixels[0 * stride];
			min1_v = max1_v = pPixels[1 * stride];
			min2_v = max2_v = pPixels[2 * stride];
			min3_v = max3_v = pPixels[3 * stride];
		}

		{
			uint32_t v0 = pPixels[4 * stride]; min0_v = basisu::minimum(min0_v, v0); max0_v = basisu::maximum(max0_v, v0);
			uint32_t v1 = pPixels[5 * stride]; min1_v = basisu::minimum(min1_v, v1); max1_v = basisu::maximum(max1_v, v1);
			uint32_t v2 = pPixels[6 * stride]; min2_v = basisu::minimum(min2_v, v2); max2_v = basisu::maximum(max2_v, v2);
			uint32_t v3 = pPixels[7 * stride]; min3_v = basisu::minimum(min3_v, v3); max3_v = basisu::maximum(max3_v, v3);
		}

		{
			uint32_t v0 = pPixels[8 * stride]; min0_v = basisu::minimum(min0_v, v0); max0_v = basisu::maximum(max0_v, v0);
			uint32_t v1 = pPixels[9 * stride]; min1_v = basisu::minimum(min1_v, v1); max1_v = basisu::maximum(max1_v, v1);
			uint32_t v2 = pPixels[10 * stride]; min2_v = basisu::minimum(min2_v, v2); max2_v = basisu::maximum(max2_v, v2);
			uint32_t v3 = pPixels[11 * stride]; min3_v = basisu::minimum(min3_v, v3); max3_v = basisu::maximum(max3_v, v3);
		}

		{
			uint32_t v0 = pPixels[12 * stride]; min0_v = basisu::minimum(min0_v, v0); max0_v = basisu::maximum(max0_v, v0);
			uint32_t v1 = pPixels[13 * stride]; min1_v = basisu::minimum(min1_v, v1); max1_v = basisu::maximum(max1_v, v1);
			uint32_t v2 = pPixels[14 * stride]; min2_v = basisu::minimum(min2_v, v2); max2_v = basisu::maximum(max2_v, v2);
			uint32_t v3 = pPixels[15 * stride]; min3_v = basisu::minimum(min3_v, v3); max3_v = basisu::maximum(max3_v, v3);
		}

		const uint32_t min_v = basisu::minimum(min0_v, min1_v, min2_v, min3_v);
		const uint32_t max_v = basisu::maximum(max0_v, max1_v, max2_v, max3_v);

		uint8_t* pDst_bytes = static_cast<uint8_t*>(pDst);
		pDst_bytes[0] = (uint8_t)max_v;
		pDst_bytes[1] = (uint8_t)min_v;

		if (max_v == min_v)
		{
			memset(pDst_bytes + 2, 0, 6);
			return;
		}

		const uint32_t delta = max_v - min_v;

		// min_v is now 0. Compute thresholds between values by scaling max_v. It's x14 because we're adding two x7 scale factors.
		const int t0 = delta * 13;
		const int t1 = delta * 11;
		const int t2 = delta * 9;
		const int t3 = delta * 7;
		const int t4 = delta * 5;
		const int t5 = delta * 3;
		const int t6 = delta * 1;

		// BC4 floors in its divisions, which we compensate for with the 4 bias.
		// This function is optimal for all possible inputs (i.e. it outputs the same results as checking all 8 values and choosing the closest one).
		const int bias = 4 - min_v * 14;

		static const uint32_t s_tran0[8] = { 1U      , 7U      , 6U      , 5U      , 4U      , 3U      , 2U      , 0U };
		static const uint32_t s_tran1[8] = { 1U << 3U, 7U << 3U, 6U << 3U, 5U << 3U, 4U << 3U, 3U << 3U, 2U << 3U, 0U << 3U };
		static const uint32_t s_tran2[8] = { 1U << 6U, 7U << 6U, 6U << 6U, 5U << 6U, 4U << 6U, 3U << 6U, 2U << 6U, 0U << 6U };
		static const uint32_t s_tran3[8] = { 1U << 9U, 7U << 9U, 6U << 9U, 5U << 9U, 4U << 9U, 3U << 9U, 2U << 9U, 0U << 9U };

		uint64_t a0, a1, a2, a3;
		{
			const int v0 = pPixels[0 * stride] * 14 + bias;
			const int v1 = pPixels[1 * stride] * 14 + bias;
			const int v2 = pPixels[2 * stride] * 14 + bias;
			const int v3 = pPixels[3 * stride] * 14 + bias;
			a0 = s_tran0[(v0 >= t0) + (v0 >= t1) + (v0 >= t2) + (v0 >= t3) + (v0 >= t4) + (v0 >= t5) + (v0 >= t6)];
			a1 = s_tran1[(v1 >= t0) + (v1 >= t1) + (v1 >= t2) + (v1 >= t3) + (v1 >= t4) + (v1 >= t5) + (v1 >= t6)];
			a2 = s_tran2[(v2 >= t0) + (v2 >= t1) + (v2 >= t2) + (v2 >= t3) + (v2 >= t4) + (v2 >= t5) + (v2 >= t6)];
			a3 = s_tran3[(v3 >= t0) + (v3 >= t1) + (v3 >= t2) + (v3 >= t3) + (v3 >= t4) + (v3 >= t5) + (v3 >= t6)];
		}

		{
			const int v0 = pPixels[4 * stride] * 14 + bias;
			const int v1 = pPixels[5 * stride] * 14 + bias;
			const int v2 = pPixels[6 * stride] * 14 + bias;
			const int v3 = pPixels[7 * stride] * 14 + bias;
			a0 |= (s_tran0[(v0 >= t0) + (v0 >= t1) + (v0 >= t2) + (v0 >= t3) + (v0 >= t4) + (v0 >= t5) + (v0 >= t6)] << 12U);
			a1 |= (s_tran1[(v1 >= t0) + (v1 >= t1) + (v1 >= t2) + (v1 >= t3) + (v1 >= t4) + (v1 >= t5) + (v1 >= t6)] << 12U);
			a2 |= (s_tran2[(v2 >= t0) + (v2 >= t1) + (v2 >= t2) + (v2 >= t3) + (v2 >= t4) + (v2 >= t5) + (v2 >= t6)] << 12U);
			a3 |= (s_tran3[(v3 >= t0) + (v3 >= t1) + (v3 >= t2) + (v3 >= t3) + (v3 >= t4) + (v3 >= t5) + (v3 >= t6)] << 12U);
		}
		
		{
			const int v0 = pPixels[8 * stride] * 14 + bias;
			const int v1 = pPixels[9 * stride] * 14 + bias;
			const int v2 = pPixels[10 * stride] * 14 + bias;
			const int v3 = pPixels[11 * stride] * 14 + bias;
			a0 |= (((uint64_t)s_tran0[(v0 >= t0) + (v0 >= t1) + (v0 >= t2) + (v0 >= t3) + (v0 >= t4) + (v0 >= t5) + (v0 >= t6)]) << 24U);
			a1 |= (((uint64_t)s_tran1[(v1 >= t0) + (v1 >= t1) + (v1 >= t2) + (v1 >= t3) + (v1 >= t4) + (v1 >= t5) + (v1 >= t6)]) << 24U);
			a2 |= (((uint64_t)s_tran2[(v2 >= t0) + (v2 >= t1) + (v2 >= t2) + (v2 >= t3) + (v2 >= t4) + (v2 >= t5) + (v2 >= t6)]) << 24U);
			a3 |= (((uint64_t)s_tran3[(v3 >= t0) + (v3 >= t1) + (v3 >= t2) + (v3 >= t3) + (v3 >= t4) + (v3 >= t5) + (v3 >= t6)]) << 24U);
		}

		{
			const int v0 = pPixels[12 * stride] * 14 + bias;
			const int v1 = pPixels[13 * stride] * 14 + bias;
			const int v2 = pPixels[14 * stride] * 14 + bias;
			const int v3 = pPixels[15 * stride] * 14 + bias;
			a0 |= (((uint64_t)s_tran0[(v0 >= t0) + (v0 >= t1) + (v0 >= t2) + (v0 >= t3) + (v0 >= t4) + (v0 >= t5) + (v0 >= t6)]) << 36U);
			a1 |= (((uint64_t)s_tran1[(v1 >= t0) + (v1 >= t1) + (v1 >= t2) + (v1 >= t3) + (v1 >= t4) + (v1 >= t5) + (v1 >= t6)]) << 36U);
			a2 |= (((uint64_t)s_tran2[(v2 >= t0) + (v2 >= t1) + (v2 >= t2) + (v2 >= t3) + (v2 >= t4) + (v2 >= t5) + (v2 >= t6)]) << 36U);
			a3 |= (((uint64_t)s_tran3[(v3 >= t0) + (v3 >= t1) + (v3 >= t2) + (v3 >= t3) + (v3 >= t4) + (v3 >= t5) + (v3 >= t6)]) << 36U);
		}

		const uint64_t f = a0 | a1 | a2 | a3;
		
		pDst_bytes[2] = (uint8_t)f;
		pDst_bytes[3] = (uint8_t)(f >> 8U);
		pDst_bytes[4] = (uint8_t)(f >> 16U);
		pDst_bytes[5] = (uint8_t)(f >> 24U);
		pDst_bytes[6] = (uint8_t)(f >> 32U);
		pDst_bytes[7] = (uint8_t)(f >> 40U);
	}

	static void bc1_find_sels(const color32 *pSrc_pixels, uint32_t lr, uint32_t lg, uint32_t lb, uint32_t hr, uint32_t hg, uint32_t hb, uint8_t sels[16])
	{
		uint32_t block_r[4], block_g[4], block_b[4];

		block_r[0] = (lr << 3) | (lr >> 2); block_g[0] = (lg << 2) | (lg >> 4);	block_b[0] = (lb << 3) | (lb >> 2);
		block_r[3] = (hr << 3) | (hr >> 2);	block_g[3] = (hg << 2) | (hg >> 4);	block_b[3] = (hb << 3) | (hb >> 2);
		block_r[1] = (block_r[0] * 2 + block_r[3]) / 3;	block_g[1] = (block_g[0] * 2 + block_g[3]) / 3;	block_b[1] = (block_b[0] * 2 + block_b[3]) / 3;
		block_r[2] = (block_r[3] * 2 + block_r[0]) / 3;	block_g[2] = (block_g[3] * 2 + block_g[0]) / 3;	block_b[2] = (block_b[3] * 2 + block_b[0]) / 3;

		int ar = block_r[3] - block_r[0], ag = block_g[3] - block_g[0], ab = block_b[3] - block_b[0];

		int dots[4];
		for (uint32_t i = 0; i < 4; i++)
			dots[i] = (int)block_r[i] * ar + (int)block_g[i] * ag + (int)block_b[i] * ab;
				
		int t0 = dots[0] + dots[1], t1 = dots[1] + dots[2], t2 = dots[2] + dots[3];

		ar *= 2; ag *= 2; ab *= 2;

		for (uint32_t i = 0; i < 16; i++)
		{
			const int d = pSrc_pixels[i].r * ar + pSrc_pixels[i].g * ag + pSrc_pixels[i].b * ab;
			static const uint8_t s_sels[4] = { 3, 2, 1, 0 };
		
			// Rounding matters here!
			// d <= t0: <=, not <, to the later LS step "sees" a wider range of selectors. It matters for quality.
			sels[i] = s_sels[(d <= t0) + (d < t1) + (d < t2)];
		}
	}

	static inline void bc1_find_sels_2(const color32* pSrc_pixels, uint32_t lr, uint32_t lg, uint32_t lb, uint32_t hr, uint32_t hg, uint32_t hb, uint8_t sels[16])
	{
		uint32_t block_r[4], block_g[4], block_b[4];

		block_r[0] = (lr << 3) | (lr >> 2); block_g[0] = (lg << 2) | (lg >> 4);	block_b[0] = (lb << 3) | (lb >> 2);
		block_r[3] = (hr << 3) | (hr >> 2);	block_g[3] = (hg << 2) | (hg >> 4);	block_b[3] = (hb << 3) | (hb >> 2);
		block_r[1] = (block_r[0] * 2 + block_r[3]) / 3;	block_g[1] = (block_g[0] * 2 + block_g[3]) / 3;	block_b[1] = (block_b[0] * 2 + block_b[3]) / 3;
		block_r[2] = (block_r[3] * 2 + block_r[0]) / 3;	block_g[2] = (block_g[3] * 2 + block_g[0]) / 3;	block_b[2] = (block_b[3] * 2 + block_b[0]) / 3;

		int ar = block_r[3] - block_r[0], ag = block_g[3] - block_g[0], ab = block_b[3] - block_b[0];

		int dots[4];
		for (uint32_t i = 0; i < 4; i++)
			dots[i] = (int)block_r[i] * ar + (int)block_g[i] * ag + (int)block_b[i] * ab;

		int t0 = dots[0] + dots[1], t1 = dots[1] + dots[2], t2 = dots[2] + dots[3];

		ar *= 2; ag *= 2; ab *= 2;

		static const uint8_t s_sels[4] = { 3, 2, 1, 0 };

		for (uint32_t i = 0; i < 16; i += 4)
		{
			const int d0 = pSrc_pixels[i+0].r * ar + pSrc_pixels[i+0].g * ag + pSrc_pixels[i+0].b * ab;
			const int d1 = pSrc_pixels[i+1].r * ar + pSrc_pixels[i+1].g * ag + pSrc_pixels[i+1].b * ab;
			const int d2 = pSrc_pixels[i+2].r * ar + pSrc_pixels[i+2].g * ag + pSrc_pixels[i+2].b * ab;
			const int d3 = pSrc_pixels[i+3].r * ar + pSrc_pixels[i+3].g * ag + pSrc_pixels[i+3].b * ab;

			sels[i+0] = s_sels[(d0 <= t0) + (d0 < t1) + (d0 < t2)];
			sels[i+1] = s_sels[(d1 <= t0) + (d1 < t1) + (d1 < t2)];
			sels[i+2] = s_sels[(d2 <= t0) + (d2 < t1) + (d2 < t2)];
			sels[i+3] = s_sels[(d3 <= t0) + (d3 < t1) + (d3 < t2)];
		}
	}
				
	static bool compute_least_squares_endpoints_rgb(const color32* pColors, const uint8_t* pSelectors, vec3F* pXl, vec3F* pXh)
	{
		// Derived from bc7enc16's LS function.
		// Least squares using normal equations: http://www.cs.cornell.edu/~bindel/class/cs3220-s12/notes/lec10.pdf 
		// I did this in matrix form first, expanded out all the ops, then optimized it a bit.
		uint32_t uq00_r = 0, uq10_r = 0, ut_r = 0, uq00_g = 0, uq10_g = 0, ut_g = 0, uq00_b = 0, uq10_b = 0, ut_b = 0;

		// This table is: 9 * (w * w), 9 * ((1.0f - w) * w), 9 * ((1.0f - w) * (1.0f - w))
		// where w is [0,1/3,2/3,1]. 9 is the perfect multiplier.
		static const uint32_t s_weight_vals[4] = { 0x000009, 0x010204, 0x040201, 0x090000 };

		uint32_t weight_accum = 0;
		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t r = pColors[i].c[0], g = pColors[i].c[1], b = pColors[i].c[2];
			const uint32_t sel = pSelectors[i];
			ut_r += r;
			ut_g += g;
			ut_b += b;
			weight_accum += s_weight_vals[sel];
			uq00_r += sel * r;
			uq00_g += sel * g;
			uq00_b += sel * b;
		}

		float q00_r = (float)uq00_r, q10_r = (float)uq10_r, t_r = (float)ut_r;
		float q00_g = (float)uq00_g, q10_g = (float)uq10_g, t_g = (float)ut_g;
		float q00_b = (float)uq00_b, q10_b = (float)uq10_b, t_b = (float)ut_b;

		q10_r = t_r * 3.0f - q00_r;
		q10_g = t_g * 3.0f - q00_g;
		q10_b = t_b * 3.0f - q00_b;

		float z00 = (float)((weight_accum >> 16) & 0xFF);
		float z10 = (float)((weight_accum >> 8) & 0xFF);
		float z11 = (float)(weight_accum & 0xFF);
		float z01 = z10;

		float det = z00 * z11 - z01 * z10;
		if (fabs(det) < 1e-8f)
			return false;

		det = 3.0f / det;

		float iz00, iz01, iz10, iz11;
		iz00 = z11 * det;
		iz01 = -z01 * det;
		iz10 = -z10 * det;
		iz11 = z00 * det;

		pXl->c[0] = iz00 * q00_r + iz01 * q10_r; pXh->c[0] = iz10 * q00_r + iz11 * q10_r;
		pXl->c[1] = iz00 * q00_g + iz01 * q10_g; pXh->c[1] = iz10 * q00_g + iz11 * q10_g;
		pXl->c[2] = iz00 * q00_b + iz01 * q10_b; pXh->c[2] = iz10 * q00_b + iz11 * q10_b;

		// Check and fix channel singularities - might not be needed, but is in UASTC's encoder.
		for (uint32_t c = 0; c < 3; c++)
		{
			if ((pXl->c[c] < 0.0f) || (pXh->c[c] > 255.0f))
			{
				uint32_t lo_v = UINT32_MAX, hi_v = 0;
				for (uint32_t i = 0; i < 16; i++)
				{
					lo_v = basisu::minimumu(lo_v, pColors[i].c[c]);
					hi_v = basisu::maximumu(hi_v, pColors[i].c[c]);
				}

				if (lo_v == hi_v)
				{
					pXl->c[c] = (float)lo_v;
					pXh->c[c] = (float)hi_v;
				}
			}
		}

		return true;
	}

	void encode_bc1_solid_block(void* pDst, uint32_t fr, uint32_t fg, uint32_t fb) 
	{
		dxt1_block* pDst_block = static_cast<dxt1_block*>(pDst);

		uint32_t mask = 0xAA;
		uint32_t max16 = (g_bc1_match5_equals_1[fr].m_hi << 11) | (g_bc1_match6_equals_1[fg].m_hi << 5) | g_bc1_match5_equals_1[fb].m_hi;
		uint32_t min16 = (g_bc1_match5_equals_1[fr].m_lo << 11) | (g_bc1_match6_equals_1[fg].m_lo << 5) | g_bc1_match5_equals_1[fb].m_lo;

		if (min16 == max16)
		{
			// Always forbid 3 color blocks
			// This is to guarantee that BC3 blocks never use punchthrough alpha (3 color) mode, which isn't supported on some (all?) GPU's.
			mask = 0;

			// Make l > h
			if (min16 > 0)
				min16--;
			else
			{
				// l = h = 0
				assert(min16 == max16 && max16 == 0);

				max16 = 1;
				min16 = 0;
				mask = 0x55;
			}

			assert(max16 > min16);
		}

		if (max16 < min16)
		{
			std::swap(max16, min16);
			mask ^= 0x55;
		}

		pDst_block->set_low_color(static_cast<uint16_t>(max16));
		pDst_block->set_high_color(static_cast<uint16_t>(min16));
		pDst_block->m_selectors[0] = static_cast<uint8_t>(mask);
		pDst_block->m_selectors[1] = static_cast<uint8_t>(mask);
		pDst_block->m_selectors[2] = static_cast<uint8_t>(mask);
		pDst_block->m_selectors[3] = static_cast<uint8_t>(mask);
	}

	static inline uint8_t to_5(uint32_t v) { v = v * 31 + 128; return (uint8_t)((v + (v >> 8)) >> 8); }
	static inline uint8_t to_6(uint32_t v) { v = v * 63 + 128; return (uint8_t)((v + (v >> 8)) >> 8); }

	// Good references: squish library, stb_dxt.
	void encode_bc1(void* pDst, const uint8_t* pPixels, uint32_t flags)
	{
		const color32* pSrc_pixels = (const color32*)pPixels;
		dxt1_block* pDst_block = static_cast<dxt1_block*>(pDst);
		
		int avg_r = -1, avg_g = 0, avg_b = 0;
		int lr = 0, lg = 0, lb = 0, hr = 0, hg = 0, hb = 0;
		uint8_t sels[16];
		
		const bool use_sels = (flags & cEncodeBC1UseSelectors) != 0;
		if (use_sels)
		{
			// Caller is jamming in their own selectors for us to try.
			const uint32_t s = pDst_block->m_selectors[0] | (pDst_block->m_selectors[1] << 8) | (pDst_block->m_selectors[2] << 16) | (pDst_block->m_selectors[3] << 24);
			
			static const uint8_t s_sel_tran[4] = { 0, 3, 1, 2 };
			
			for (uint32_t i = 0; i < 16; i++)
				sels[i] = s_sel_tran[(s >> (i * 2)) & 3];
		}
		else
		{
			const uint32_t fr = pSrc_pixels[0].r, fg = pSrc_pixels[0].g, fb = pSrc_pixels[0].b;

			uint32_t j;
			for (j = 1; j < 16; j++)
				if ((pSrc_pixels[j].r != fr) || (pSrc_pixels[j].g != fg) || (pSrc_pixels[j].b != fb))
					break;
						
			if (j == 16)
			{
				encode_bc1_solid_block(pDst, fr, fg, fb);
				return;
			}
			
			// Select 2 colors along the principle axis. (There must be a faster/simpler way.)
			int total_r = fr, total_g = fg, total_b = fb;
			int max_r = fr, max_g = fg, max_b = fb;
			int min_r = fr, min_g = fg, min_b = fb;
			for (uint32_t i = 1; i < 16; i++)
			{
				const int r = pSrc_pixels[i].r, g = pSrc_pixels[i].g, b = pSrc_pixels[i].b;
				max_r = basisu::maximum(max_r, r); max_g = basisu::maximum(max_g, g); max_b = basisu::maximum(max_b, b);
				min_r = basisu::minimum(min_r, r); min_g = basisu::minimum(min_g, g); min_b = basisu::minimum(min_b, b);
				total_r += r; total_g += g; total_b += b;
			}

			avg_r = (total_r + 8) >> 4;
			avg_g = (total_g + 8) >> 4;
			avg_b = (total_b + 8) >> 4;

			int icov[6] = { 0, 0, 0, 0, 0, 0 };
			for (uint32_t i = 0; i < 16; i++)
			{
				int r = (int)pSrc_pixels[i].r - avg_r;
				int g = (int)pSrc_pixels[i].g - avg_g;
				int b = (int)pSrc_pixels[i].b - avg_b;
				icov[0] += r * r;
				icov[1] += r * g;
				icov[2] += r * b;
				icov[3] += g * g;
				icov[4] += g * b;
				icov[5] += b * b;
			}

			float cov[6];
			for (uint32_t i = 0; i < 6; i++)
				cov[i] = static_cast<float>(icov[i])* (1.0f / 255.0f);
			
#if 0
			// Seems silly to use full PCA to choose 2 colors. The diff in avg. PSNR between using PCA vs. not is small (~.025 difference).
			// TODO: Try 2 or 3 different normalized diagonal vectors, choose the one that results in the largest dot delta
			int saxis_r = max_r - min_r;
			int saxis_g = max_g - min_g;
			int saxis_b = max_b - min_b;
#else
			float xr = (float)(max_r - min_r);
			float xg = (float)(max_g - min_g);
			float xb = (float)(max_b - min_b);
			//float xr = (float)(max_r - avg_r); // max-avg is nearly the same, and doesn't require computing min's
			//float xg = (float)(max_g - avg_g);
			//float xb = (float)(max_b - avg_b);
			for (uint32_t power_iter = 0; power_iter < 4; power_iter++)
			{
				float r = xr * cov[0] + xg * cov[1] + xb * cov[2];
				float g = xr * cov[1] + xg * cov[3] + xb * cov[4];
				float b = xr * cov[2] + xg * cov[4] + xb * cov[5];
				xr = r; xg = g; xb = b;
			}

			float k = basisu::maximum(fabsf(xr), fabsf(xg), fabsf(xb));
			int saxis_r = 306, saxis_g = 601, saxis_b = 117;
			if (k >= 2)
			{
				float m = 1024.0f / k;
				saxis_r = (int)(xr * m);
				saxis_g = (int)(xg * m);
				saxis_b = (int)(xb * m);
			}
#endif
			
			int low_dot = INT_MAX, high_dot = INT_MIN, low_c = 0, high_c = 0;
			for (uint32_t i = 0; i < 16; i++)
			{
				int dot = pSrc_pixels[i].r * saxis_r + pSrc_pixels[i].g * saxis_g + pSrc_pixels[i].b * saxis_b;
				if (dot < low_dot)
				{
					low_dot = dot;
					low_c = i;
				}
				if (dot > high_dot)
				{
					high_dot = dot;
					high_c = i;
				}
			}

			lr = to_5(pSrc_pixels[low_c].r);
			lg = to_6(pSrc_pixels[low_c].g);
			lb = to_5(pSrc_pixels[low_c].b);

			hr = to_5(pSrc_pixels[high_c].r);
			hg = to_6(pSrc_pixels[high_c].g);
			hb = to_5(pSrc_pixels[high_c].b);
						
			bc1_find_sels(pSrc_pixels, lr, lg, lb, hr, hg, hb, sels);
		} // if (use_sels)

		const uint32_t total_ls_passes = (flags & cEncodeBC1HigherQuality) ? 3 : (flags & cEncodeBC1HighQuality ? 2 : 1);
		for (uint32_t ls_pass = 0; ls_pass < total_ls_passes; ls_pass++)
		{
			// This is where the real magic happens. We have an array of candidate selectors, so let's use least squares to compute the optimal low/high endpoint colors.
			vec3F xl, xh;
			if (!compute_least_squares_endpoints_rgb(pSrc_pixels, sels, &xl, &xh))
			{
				if (avg_r < 0)
				{
					int total_r = 0, total_g = 0, total_b = 0;
					for (uint32_t i = 0; i < 16; i++)
					{
						total_r += pSrc_pixels[i].r;
						total_g += pSrc_pixels[i].g;
						total_b += pSrc_pixels[i].b;
					}

					avg_r = (total_r + 8) >> 4;
					avg_g = (total_g + 8) >> 4;
					avg_b = (total_b + 8) >> 4;
				}

				// All selectors equal - treat it as a solid block which should always be equal or better.
				lr = g_bc1_match5_equals_1[avg_r].m_hi;
				lg = g_bc1_match6_equals_1[avg_g].m_hi;
				lb = g_bc1_match5_equals_1[avg_b].m_hi;

				hr = g_bc1_match5_equals_1[avg_r].m_lo;
				hg = g_bc1_match6_equals_1[avg_g].m_lo;
				hb = g_bc1_match5_equals_1[avg_b].m_lo;

				// In high/higher quality mode, let it try again in case the optimal tables have caused the sels to diverge.
			}
			else
			{
				lr = basisu::clamp((int)((xl.c[0]) * (31.0f / 255.0f) + .5f), 0, 31);
				lg = basisu::clamp((int)((xl.c[1]) * (63.0f / 255.0f) + .5f), 0, 63);
				lb = basisu::clamp((int)((xl.c[2]) * (31.0f / 255.0f) + .5f), 0, 31);

				hr = basisu::clamp((int)((xh.c[0]) * (31.0f / 255.0f) + .5f), 0, 31);
				hg = basisu::clamp((int)((xh.c[1]) * (63.0f / 255.0f) + .5f), 0, 63);
				hb = basisu::clamp((int)((xh.c[2]) * (31.0f / 255.0f) + .5f), 0, 31);
			}
									
			bc1_find_sels(pSrc_pixels, lr, lg, lb, hr, hg, hb, sels);
		}

		uint32_t lc16 = dxt1_block::pack_unscaled_color(lr, lg, lb);
		uint32_t hc16 = dxt1_block::pack_unscaled_color(hr, hg, hb);
				
		// Always forbid 3 color blocks
		if (lc16 == hc16)
		{
			uint8_t mask = 0;

			// Make l > h
			if (hc16 > 0)
				hc16--;
			else
			{
				// lc16 = hc16 = 0
				assert(lc16 == hc16 && hc16 == 0);

				hc16 = 0;
				lc16 = 1;
				mask = 0x55; // select hc16
			}

			assert(lc16 > hc16);
			pDst_block->set_low_color(static_cast<uint16_t>(lc16));
			pDst_block->set_high_color(static_cast<uint16_t>(hc16));

			pDst_block->m_selectors[0] = mask;
			pDst_block->m_selectors[1] = mask;
			pDst_block->m_selectors[2] = mask;
			pDst_block->m_selectors[3] = mask;
		}
		else
		{
			uint8_t invert_mask = 0;
			if (lc16 < hc16)
			{
				std::swap(lc16, hc16);
				invert_mask = 0x55;
			}

			assert(lc16 > hc16);
			pDst_block->set_low_color((uint16_t)lc16);
			pDst_block->set_high_color((uint16_t)hc16);

			uint32_t packed_sels = 0;
			static const uint8_t s_sel_trans[4] = { 0, 2, 3, 1 };
			for (uint32_t i = 0; i < 16; i++)
				packed_sels |= ((uint32_t)s_sel_trans[sels[i]] << (i * 2));

			pDst_block->m_selectors[0] = (uint8_t)packed_sels ^ invert_mask;
			pDst_block->m_selectors[1] = (uint8_t)(packed_sels >> 8) ^ invert_mask;
			pDst_block->m_selectors[2] = (uint8_t)(packed_sels >> 16) ^ invert_mask;
			pDst_block->m_selectors[3] = (uint8_t)(packed_sels >> 24) ^ invert_mask;
		}
	}
		
	void encode_bc1_alt(void* pDst, const uint8_t* pPixels, uint32_t flags)
	{
		const color32* pSrc_pixels = (const color32*)pPixels;
		dxt1_block* pDst_block = static_cast<dxt1_block*>(pDst);

		int avg_r = -1, avg_g = 0, avg_b = 0;
		int lr = 0, lg = 0, lb = 0, hr = 0, hg = 0, hb = 0;
		uint8_t sels[16];

		const bool use_sels = (flags & cEncodeBC1UseSelectors) != 0;
		if (use_sels)
		{
			// Caller is jamming in their own selectors for us to try.
			const uint32_t s = pDst_block->m_selectors[0] | (pDst_block->m_selectors[1] << 8) | (pDst_block->m_selectors[2] << 16) | (pDst_block->m_selectors[3] << 24);

			static const uint8_t s_sel_tran[4] = { 0, 3, 1, 2 };

			for (uint32_t i = 0; i < 16; i++)
				sels[i] = s_sel_tran[(s >> (i * 2)) & 3];
		}
		else
		{
			const uint32_t fr = pSrc_pixels[0].r, fg = pSrc_pixels[0].g, fb = pSrc_pixels[0].b;

			uint32_t j;
			for (j = 1; j < 16; j++)
				if ((pSrc_pixels[j].r != fr) || (pSrc_pixels[j].g != fg) || (pSrc_pixels[j].b != fb))
					break;

			if (j == 16)
			{
				encode_bc1_solid_block(pDst, fr, fg, fb);
				return;
			}

			// Select 2 colors along the principle axis. (There must be a faster/simpler way.)
			int total_r = fr, total_g = fg, total_b = fb;
			int max_r = fr, max_g = fg, max_b = fb;
			int min_r = fr, min_g = fg, min_b = fb;
			uint32_t grayscale_flag = (fr == fg) && (fr == fb);
			for (uint32_t i = 1; i < 16; i++)
			{
				const int r = pSrc_pixels[i].r, g = pSrc_pixels[i].g, b = pSrc_pixels[i].b;
				grayscale_flag &= ((r == g) && (r == b));
				max_r = basisu::maximum(max_r, r); max_g = basisu::maximum(max_g, g); max_b = basisu::maximum(max_b, b);
				min_r = basisu::minimum(min_r, r); min_g = basisu::minimum(min_g, g); min_b = basisu::minimum(min_b, b);
				total_r += r; total_g += g; total_b += b;
			}
						
			if (grayscale_flag) 
			{
				// Grayscale blocks are a common enough case to specialize.
				if ((max_r - min_r) < 2)
				{
					lr = lb = hr = hb = to_5(fr);
					lg = hg = to_6(fr);
				}
				else
				{
					lr = lb = to_5(min_r);
					lg = to_6(min_r);

					hr = hb = to_5(max_r);
					hg = to_6(max_r);
				}
			}
			else
			{
				avg_r = (total_r + 8) >> 4;
				avg_g = (total_g + 8) >> 4;
				avg_b = (total_b + 8) >> 4;

				// Find the shortest vector from a AABB corner to the block's average color.
				// This is to help avoid outliers.

				uint32_t dist[3][2];
				dist[0][0] = basisu::square(min_r - avg_r) << 3; dist[0][1] = basisu::square(max_r - avg_r) << 3;
				dist[1][0] = basisu::square(min_g - avg_g) << 3; dist[1][1] = basisu::square(max_g - avg_g) << 3;
				dist[2][0] = basisu::square(min_b - avg_b) << 3; dist[2][1] = basisu::square(max_b - avg_b) << 3;

				uint32_t min_d0 = (dist[0][0] + dist[1][0] + dist[2][0]);
				uint32_t d4 = (dist[0][0] + dist[1][0] + dist[2][1]) | 4;
				min_d0 = basisu::minimum(min_d0, d4);

				uint32_t min_d1 = (dist[0][1] + dist[1][0] + dist[2][0]) | 1;
				uint32_t d5 = (dist[0][1] + dist[1][0] + dist[2][1]) | 5;
				min_d1 = basisu::minimum(min_d1, d5);

				uint32_t d2 = (dist[0][0] + dist[1][1] + dist[2][0]) | 2;
				min_d0 = basisu::minimum(min_d0, d2);

				uint32_t d3 = (dist[0][1] + dist[1][1] + dist[2][0]) | 3;
				min_d1 = basisu::minimum(min_d1, d3);

				uint32_t d6 = (dist[0][0] + dist[1][1] + dist[2][1]) | 6;
				min_d0 = basisu::minimum(min_d0, d6);

				uint32_t d7 = (dist[0][1] + dist[1][1] + dist[2][1]) | 7;
				min_d1 = basisu::minimum(min_d1, d7);

				uint32_t min_d = basisu::minimum(min_d0, min_d1);
				uint32_t best_i = min_d & 7;

				int delta_r = (best_i & 1) ? (max_r - avg_r) : (avg_r - min_r);
				int delta_g = (best_i & 2) ? (max_g - avg_g) : (avg_g - min_g);
				int delta_b = (best_i & 4) ? (max_b - avg_b) : (avg_b - min_b);

				// Note: if delta_r/g/b==0, we actually want to choose a single color, so the block average color optimization kicks in.
				uint32_t low_c = 0, high_c = 0;
				if ((delta_r | delta_g | delta_b) != 0)
				{
					// Now we have a smaller AABB going from the block's average color to a cornerpoint of the larger AABB.
					// Project all pixels colors along the 4 vectors going from a smaller AABB cornerpoint to the opposite cornerpoint, find largest projection.
					// One of these vectors will be a decent approximation of the block's PCA.
					const int saxis0_r = delta_r, saxis0_g = delta_g, saxis0_b = delta_b;

					int low_dot0 = INT_MAX, high_dot0 = INT_MIN;
					int low_dot1 = INT_MAX, high_dot1 = INT_MIN;
					int low_dot2 = INT_MAX, high_dot2 = INT_MIN;
					int low_dot3 = INT_MAX, high_dot3 = INT_MIN;

					//int low_c0, low_c1, low_c2, low_c3;
					//int high_c0, high_c1, high_c2, high_c3;

					for (uint32_t i = 0; i < 16; i++)
					{
						const int dotx = pSrc_pixels[i].r * saxis0_r;
						const int doty = pSrc_pixels[i].g * saxis0_g;
						const int dotz = pSrc_pixels[i].b * saxis0_b;

						const int dot0 = ((dotz + dotx + doty) << 4) + i;
						const int dot1 = ((dotz - dotx - doty) << 4) + i;
						const int dot2 = ((dotz - dotx + doty) << 4) + i;
						const int dot3 = ((dotz + dotx - doty) << 4) + i;

						if (dot0 < low_dot0)
						{
							low_dot0 = dot0;
							//low_c0 = i;
						}
						if ((dot0 ^ 15) > high_dot0)
						{
							high_dot0 = dot0 ^ 15;
							//high_c0 = i;
						}

						if (dot1 < low_dot1)
						{
							low_dot1 = dot1;
							//low_c1 = i;
						}
						if ((dot1 ^ 15) > high_dot1)
						{
							high_dot1 = dot1 ^ 15;
							//high_c1 = i;
						}

						if (dot2 < low_dot2)
						{
							low_dot2 = dot2;
							//low_c2 = i;
						}
						if ((dot2 ^ 15) > high_dot2)
						{
							high_dot2 = dot2 ^ 15;
							//high_c2 = i;
						}

						if (dot3 < low_dot3)
						{
							low_dot3 = dot3;
							//low_c3 = i;
						}
						if ((dot3 ^ 15) > high_dot3)
						{
							high_dot3 = dot3 ^ 15;
							//high_c3 = i;
						}
					}

					low_c = low_dot0 & 15;
					high_c = ~high_dot0 & 15;
					uint32_t r = (high_dot0 & ~15) - (low_dot0 & ~15);

					uint32_t tr = (high_dot1 & ~15) - (low_dot1 & ~15);
					if (tr > r) {
						low_c = low_dot1 & 15;
						high_c = ~high_dot1 & 15;
						r = tr;
					}

					tr = (high_dot2 & ~15) - (low_dot2 & ~15);
					if (tr > r) {
						low_c = low_dot2 & 15;
						high_c = ~high_dot2 & 15;
						r = tr;
					}

					tr = (high_dot3 & ~15) - (low_dot3 & ~15);
					if (tr > r) {
						low_c = low_dot3 & 15;
						high_c = ~high_dot3 & 15;
					}
				}

				lr = to_5(pSrc_pixels[low_c].r);
				lg = to_6(pSrc_pixels[low_c].g);
				lb = to_5(pSrc_pixels[low_c].b);

				hr = to_5(pSrc_pixels[high_c].r);
				hg = to_6(pSrc_pixels[high_c].g);
				hb = to_5(pSrc_pixels[high_c].b);
			}

			bc1_find_sels_2(pSrc_pixels, lr, lg, lb, hr, hg, hb, sels);
		} // if (use_sels)

		const uint32_t total_ls_passes = (flags & cEncodeBC1HigherQuality) ? 3 : (flags & cEncodeBC1HighQuality ? 2 : 1);
		for (uint32_t ls_pass = 0; ls_pass < total_ls_passes; ls_pass++)
		{
			int prev_lr = lr, prev_lg = lg, prev_lb = lb, prev_hr = hr, prev_hg = hg, prev_hb = hb;

			// This is where the real magic happens. We have an array of candidate selectors, so let's use least squares to compute the optimal low/high endpoint colors.
			vec3F xl, xh;
			if (!compute_least_squares_endpoints_rgb(pSrc_pixels, sels, &xl, &xh))
			{
				if (avg_r < 0)
				{
					int total_r = 0, total_g = 0, total_b = 0;
					for (uint32_t i = 0; i < 16; i++)
					{
						total_r += pSrc_pixels[i].r;
						total_g += pSrc_pixels[i].g;
						total_b += pSrc_pixels[i].b;
					}

					avg_r = (total_r + 8) >> 4;
					avg_g = (total_g + 8) >> 4;
					avg_b = (total_b + 8) >> 4;
				}

				// All selectors equal - treat it as a solid block which should always be equal or better.
				lr = g_bc1_match5_equals_1[avg_r].m_hi;
				lg = g_bc1_match6_equals_1[avg_g].m_hi;
				lb = g_bc1_match5_equals_1[avg_b].m_hi;

				hr = g_bc1_match5_equals_1[avg_r].m_lo;
				hg = g_bc1_match6_equals_1[avg_g].m_lo;
				hb = g_bc1_match5_equals_1[avg_b].m_lo;

				// In high/higher quality mode, let it try again in case the optimal tables have caused the sels to diverge.
			}
			else
			{
				lr = basisu::clamp((int)((xl.c[0]) * (31.0f / 255.0f) + .5f), 0, 31);
				lg = basisu::clamp((int)((xl.c[1]) * (63.0f / 255.0f) + .5f), 0, 63);
				lb = basisu::clamp((int)((xl.c[2]) * (31.0f / 255.0f) + .5f), 0, 31);

				hr = basisu::clamp((int)((xh.c[0]) * (31.0f / 255.0f) + .5f), 0, 31);
				hg = basisu::clamp((int)((xh.c[1]) * (63.0f / 255.0f) + .5f), 0, 63);
				hb = basisu::clamp((int)((xh.c[2]) * (31.0f / 255.0f) + .5f), 0, 31);
			}

			if ((prev_lr == lr) && (prev_lg == lg) && (prev_lb == lb) && (prev_hr == hr) && (prev_hg == hg) && (prev_hb == hb))
				break;

			bc1_find_sels_2(pSrc_pixels, lr, lg, lb, hr, hg, hb, sels);
		}

		uint32_t lc16 = dxt1_block::pack_unscaled_color(lr, lg, lb);
		uint32_t hc16 = dxt1_block::pack_unscaled_color(hr, hg, hb);

		// Always forbid 3 color blocks
		if (lc16 == hc16)
		{
			uint8_t mask = 0;

			// Make l > h
			if (hc16 > 0)
				hc16--;
			else
			{
				// lc16 = hc16 = 0
				assert(lc16 == hc16 && hc16 == 0);

				hc16 = 0;
				lc16 = 1;
				mask = 0x55; // select hc16
			}

			assert(lc16 > hc16);
			pDst_block->set_low_color(static_cast<uint16_t>(lc16));
			pDst_block->set_high_color(static_cast<uint16_t>(hc16));

			pDst_block->m_selectors[0] = mask;
			pDst_block->m_selectors[1] = mask;
			pDst_block->m_selectors[2] = mask;
			pDst_block->m_selectors[3] = mask;
		}
		else
		{
			uint8_t invert_mask = 0;
			if (lc16 < hc16)
			{
				std::swap(lc16, hc16);
				invert_mask = 0x55;
			}

			assert(lc16 > hc16);
			pDst_block->set_low_color((uint16_t)lc16);
			pDst_block->set_high_color((uint16_t)hc16);

			uint32_t packed_sels = 0;
			static const uint8_t s_sel_trans[4] = { 0, 2, 3, 1 };
			for (uint32_t i = 0; i < 16; i++)
				packed_sels |= ((uint32_t)s_sel_trans[sels[i]] << (i * 2));

			pDst_block->m_selectors[0] = (uint8_t)packed_sels ^ invert_mask;
			pDst_block->m_selectors[1] = (uint8_t)(packed_sels >> 8) ^ invert_mask;
			pDst_block->m_selectors[2] = (uint8_t)(packed_sels >> 16) ^ invert_mask;
			pDst_block->m_selectors[3] = (uint8_t)(packed_sels >> 24) ^ invert_mask;
		}
	}

	// Scale the UASTC first subset endpoints and first plane's weight indices directly to BC1's - fastest.
	void transcode_uastc_to_bc1_hint0(const unpacked_uastc_block& unpacked_src_blk, void* pDst)
	{
		const uint32_t mode = unpacked_src_blk.m_mode;
		const astc_block_desc& astc_blk = unpacked_src_blk.m_astc;

		dxt1_block& b = *static_cast<dxt1_block*>(pDst);

		const uint32_t endpoint_range = g_uastc_mode_endpoint_ranges[mode];

		const uint32_t total_comps = g_uastc_mode_comps[mode];

		if (total_comps == 2)
		{
			const uint32_t l = g_astc_unquant[endpoint_range][astc_blk.m_endpoints[0]].m_unquant;
			const uint32_t h = g_astc_unquant[endpoint_range][astc_blk.m_endpoints[1]].m_unquant;

			b.set_low_color(dxt1_block::pack_color(color32(l, l, l, 255), true, 127));
			b.set_high_color(dxt1_block::pack_color(color32(h, h, h, 255), true, 127));
		}
		else
		{
			b.set_low_color(dxt1_block::pack_color(
				color32(g_astc_unquant[endpoint_range][astc_blk.m_endpoints[0]].m_unquant,
					g_astc_unquant[endpoint_range][astc_blk.m_endpoints[2]].m_unquant,
					g_astc_unquant[endpoint_range][astc_blk.m_endpoints[4]].m_unquant,
					255), true, 127)
			);

			b.set_high_color(dxt1_block::pack_color(
				color32(g_astc_unquant[endpoint_range][astc_blk.m_endpoints[1]].m_unquant,
					g_astc_unquant[endpoint_range][astc_blk.m_endpoints[3]].m_unquant,
					g_astc_unquant[endpoint_range][astc_blk.m_endpoints[5]].m_unquant,
					255), true, 127)
			);
		}

		if (b.get_low_color() == b.get_high_color())
		{
			// Always forbid 3 color blocks
			uint16_t lc16 = (uint16_t)b.get_low_color();
			uint16_t hc16 = (uint16_t)b.get_high_color();
			
			uint8_t mask = 0;

			// Make l > h
			if (hc16 > 0)
				hc16--;
			else
			{
				// lc16 = hc16 = 0
				assert(lc16 == hc16 && hc16 == 0);

				hc16 = 0;
				lc16 = 1;
				mask = 0x55; // select hc16
			}

			assert(lc16 > hc16);
			b.set_low_color(static_cast<uint16_t>(lc16));
			b.set_high_color(static_cast<uint16_t>(hc16));

			b.m_selectors[0] = mask;
			b.m_selectors[1] = mask;
			b.m_selectors[2] = mask;
			b.m_selectors[3] = mask;
		}
		else
		{
			bool invert = false;
			if (b.get_low_color() < b.get_high_color())
			{
				std::swap(b.m_low_color[0], b.m_high_color[0]);
				std::swap(b.m_low_color[1], b.m_high_color[1]);
				invert = true;
			}

			const uint8_t* pTran = s_uastc_to_bc1_weights[g_uastc_mode_weight_bits[mode]];

			const uint32_t plane_shift = g_uastc_mode_planes[mode] - 1;

			uint32_t sels = 0;
			for (int i = 15; i >= 0; --i)
			{
				uint32_t s = pTran[astc_blk.m_weights[i << plane_shift]];

				if (invert)
					s ^= 1;

				sels = (sels << 2) | s;
			}
			b.m_selectors[0] = sels & 0xFF;
			b.m_selectors[1] = (sels >> 8) & 0xFF;
			b.m_selectors[2] = (sels >> 16) & 0xFF;
			b.m_selectors[3] = (sels >> 24) & 0xFF;
		}
	}

	// Scale the UASTC first plane's weight indices to BC1, use 1 or 2 least squares passes to compute endpoints - no PCA needed.
	void transcode_uastc_to_bc1_hint1(const unpacked_uastc_block& unpacked_src_blk, const color32 block_pixels[4][4], void* pDst, bool high_quality)
	{
		const uint32_t mode = unpacked_src_blk.m_mode;

		const astc_block_desc& astc_blk = unpacked_src_blk.m_astc;

		dxt1_block& b = *static_cast<dxt1_block*>(pDst);

		b.set_low_color(1);
		b.set_high_color(0);

		const uint8_t* pTran = s_uastc_to_bc1_weights[g_uastc_mode_weight_bits[mode]];

		const uint32_t plane_shift = g_uastc_mode_planes[mode] - 1;

		uint32_t sels = 0;
		for (int i = 15; i >= 0; --i)
		{
			sels <<= 2;
			sels |= pTran[astc_blk.m_weights[i << plane_shift]];
		}

		b.m_selectors[0] = sels & 0xFF;
		b.m_selectors[1] = (sels >> 8) & 0xFF;
		b.m_selectors[2] = (sels >> 16) & 0xFF;
		b.m_selectors[3] = (sels >> 24) & 0xFF;

		encode_bc1(&b, (const uint8_t*)&block_pixels[0][0].c[0], (high_quality ? cEncodeBC1HighQuality : 0) | cEncodeBC1UseSelectors);
	}

	bool transcode_uastc_to_bc1(const uastc_block& src_blk, void* pDst, bool high_quality)
	{
		unpacked_uastc_block unpacked_src_blk;
		if (!unpack_uastc(src_blk, unpacked_src_blk, false))
			return false;

		const uint32_t mode = unpacked_src_blk.m_mode;

		if (mode == UASTC_MODE_INDEX_SOLID_COLOR)
		{
			encode_bc1_solid_block(pDst, unpacked_src_blk.m_solid_color.r, unpacked_src_blk.m_solid_color.g, unpacked_src_blk.m_solid_color.b);
			return true;
		}

		if ((!high_quality) && (unpacked_src_blk.m_bc1_hint0))
			transcode_uastc_to_bc1_hint0(unpacked_src_blk, pDst);
		else
		{
			color32 block_pixels[4][4];
			const bool unpack_srgb = false;
			if (!unpack_uastc(unpacked_src_blk, &block_pixels[0][0], unpack_srgb))
				return false;

			if (unpacked_src_blk.m_bc1_hint1)
				transcode_uastc_to_bc1_hint1(unpacked_src_blk, block_pixels, pDst, high_quality);
			else
				encode_bc1(pDst, &block_pixels[0][0].r, high_quality ? cEncodeBC1HighQuality : 0);
		}

		return true;
	}

	static void write_bc4_solid_block(uint8_t* pDst, uint32_t a)
	{
		pDst[0] = (uint8_t)a;
		pDst[1] = (uint8_t)a;
		memset(pDst + 2, 0, 6);
	}

	bool transcode_uastc_to_bc3(const uastc_block& src_blk, void* pDst, bool high_quality)
	{
		unpacked_uastc_block unpacked_src_blk;
		if (!unpack_uastc(src_blk, unpacked_src_blk, false))
			return false;

		const uint32_t mode = unpacked_src_blk.m_mode;

		void* pBC4_block = pDst;
		dxt1_block* pBC1_block = &static_cast<dxt1_block*>(pDst)[1];

		if (mode == UASTC_MODE_INDEX_SOLID_COLOR)
		{
			write_bc4_solid_block(static_cast<uint8_t*>(pBC4_block), unpacked_src_blk.m_solid_color.a);
			encode_bc1_solid_block(pBC1_block, unpacked_src_blk.m_solid_color.r, unpacked_src_blk.m_solid_color.g, unpacked_src_blk.m_solid_color.b);
			return true;
		}

		color32 block_pixels[4][4];
		const bool unpack_srgb = false;
		if (!unpack_uastc(unpacked_src_blk, &block_pixels[0][0], unpack_srgb))
			return false;

		basist::encode_bc4(pBC4_block, &block_pixels[0][0].a, sizeof(color32));

		if ((!high_quality) && (unpacked_src_blk.m_bc1_hint0))
			transcode_uastc_to_bc1_hint0(unpacked_src_blk, pBC1_block);
		else
		{
			if (unpacked_src_blk.m_bc1_hint1)
				transcode_uastc_to_bc1_hint1(unpacked_src_blk, block_pixels, pBC1_block, high_quality);
			else
				encode_bc1(pBC1_block, &block_pixels[0][0].r, high_quality ? cEncodeBC1HighQuality : 0);
		}

		return true;
	}

	bool transcode_uastc_to_bc4(const uastc_block& src_blk, void* pDst, bool high_quality, uint32_t chan0)
	{
		BASISU_NOTE_UNUSED(high_quality);

		unpacked_uastc_block unpacked_src_blk;
		if (!unpack_uastc(src_blk, unpacked_src_blk, false))
			return false;

		const uint32_t mode = unpacked_src_blk.m_mode;

		void* pBC4_block = pDst;

		if (mode == UASTC_MODE_INDEX_SOLID_COLOR)
		{
			write_bc4_solid_block(static_cast<uint8_t*>(pBC4_block), unpacked_src_blk.m_solid_color.c[chan0]);
			return true;
		}

		color32 block_pixels[4][4];
		const bool unpack_srgb = false;
		if (!unpack_uastc(unpacked_src_blk, &block_pixels[0][0], unpack_srgb))
			return false;

		basist::encode_bc4(pBC4_block, &block_pixels[0][0].c[chan0], sizeof(color32));

		return true;
	}

	bool transcode_uastc_to_bc5(const uastc_block& src_blk, void* pDst, bool high_quality, uint32_t chan0, uint32_t chan1)
	{
		BASISU_NOTE_UNUSED(high_quality);

		unpacked_uastc_block unpacked_src_blk;
		if (!unpack_uastc(src_blk, unpacked_src_blk, false))
			return false;

		const uint32_t mode = unpacked_src_blk.m_mode;

		void* pBC4_block0 = pDst;
		void* pBC4_block1 = (uint8_t*)pDst + 8;

		if (mode == UASTC_MODE_INDEX_SOLID_COLOR)
		{
			write_bc4_solid_block(static_cast<uint8_t*>(pBC4_block0), unpacked_src_blk.m_solid_color.c[chan0]);
			write_bc4_solid_block(static_cast<uint8_t*>(pBC4_block1), unpacked_src_blk.m_solid_color.c[chan1]);
			return true;
		}

		color32 block_pixels[4][4];
		const bool unpack_srgb = false;
		if (!unpack_uastc(unpacked_src_blk, &block_pixels[0][0], unpack_srgb))
			return false;

		basist::encode_bc4(pBC4_block0, &block_pixels[0][0].c[chan0], sizeof(color32));
		basist::encode_bc4(pBC4_block1, &block_pixels[0][0].c[chan1], sizeof(color32));

		return true;
	}

	static const uint8_t s_etc2_eac_bit_ofs[16] = { 45, 33, 21, 9, 42, 30, 18, 6, 39, 27, 15, 3,	36, 24, 12,	0 };

	static void pack_eac_solid_block(eac_block& blk, uint32_t a)
	{
		blk.m_base = static_cast<uint8_t>(a);
		blk.m_table = 13;
		blk.m_multiplier = 0;
				
		memcpy(blk.m_selectors, g_etc2_eac_a8_sel4, sizeof(g_etc2_eac_a8_sel4));

		return;
	}

	// Only checks 4 tables.
	static void pack_eac(eac_block& blk, const uint8_t* pPixels, uint32_t stride)
	{
		uint32_t min_alpha = 255, max_alpha = 0;
		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t a = pPixels[i * stride];
			if (a < min_alpha) min_alpha = a;
			if (a > max_alpha) max_alpha = a;
		}

		if (min_alpha == max_alpha)
		{
			pack_eac_solid_block(blk, min_alpha);
			return;
		}

		const uint32_t alpha_range = max_alpha - min_alpha;

		const uint32_t SINGLE_TABLE_THRESH = 5;
		if (alpha_range <= SINGLE_TABLE_THRESH)
		{
			// If alpha_range <= 5 table 13 is lossless
			int base = clamp255((int)max_alpha - 2);

			blk.m_base = base;
			blk.m_multiplier = 1;
			blk.m_table = 13;

			base -= 3;

			uint64_t packed_sels = 0;
			for (uint32_t i = 0; i < 16; i++)
			{
				const int a = pPixels[i * stride];

				static const uint8_t s_sels[6] = { 2, 1, 0, 4, 5, 6 };

				int sel = a - base;
				assert(sel >= 0 && sel <= 5);

				packed_sels |= (static_cast<uint64_t>(s_sels[sel]) << s_etc2_eac_bit_ofs[i]);
			}

			blk.set_selector_bits(packed_sels);

			return;
		}

		const uint32_t T0 = 2, T1 = 8, T2 = 11, T3 = 13;
		static const uint8_t s_tables[4] = { T0, T1, T2, T3 };

		int base[4], mul[4];
		uint32_t mul_or = 0;
		for (uint32_t i = 0; i < 4; i++)
		{
			const uint32_t table = s_tables[i];

			const float range = (float)(g_eac_modifier_table[table][ETC2_EAC_MAX_VALUE_SELECTOR] - g_eac_modifier_table[table][ETC2_EAC_MIN_VALUE_SELECTOR]);

			base[i] = clamp255((int)roundf(basisu::lerp((float)min_alpha, (float)max_alpha, (float)(0 - g_eac_modifier_table[table][ETC2_EAC_MIN_VALUE_SELECTOR]) / range)));
			mul[i] = clampi((int)roundf(alpha_range / range), 1, 15);
			mul_or |= mul[i];
		}

		uint32_t total_err[4] = { 0, 0, 0, 0 };
		uint8_t sels[4][16];

		for (uint32_t i = 0; i < 16; i++)
		{
			const int a = pPixels[i * stride];

			uint32_t l0 = UINT32_MAX, l1 = UINT32_MAX, l2 = UINT32_MAX, l3 = UINT32_MAX;

			if ((a < 7) || (a > (255 - 7)))
			{
				for (uint32_t s = 0; s < 8; s++)
				{
					const int v0 = clamp255(mul[0] * g_eac_modifier_table[T0][s] + base[0]);
					const int v1 = clamp255(mul[1] * g_eac_modifier_table[T1][s] + base[1]);
					const int v2 = clamp255(mul[2] * g_eac_modifier_table[T2][s] + base[2]);
					const int v3 = clamp255(mul[3] * g_eac_modifier_table[T3][s] + base[3]);

					l0 = basisu::minimum(l0, (basisu::iabs(v0 - a) << 3) | s);
					l1 = basisu::minimum(l1, (basisu::iabs(v1 - a) << 3) | s);
					l2 = basisu::minimum(l2, (basisu::iabs(v2 - a) << 3) | s);
					l3 = basisu::minimum(l3, (basisu::iabs(v3 - a) << 3) | s);
				}
			}
			else if (mul_or == 1)
			{
				const int a0 = base[0] - a, a1 = base[1] - a, a2 = base[2] - a, a3 = base[3] - a;

				for (uint32_t s = 0; s < 8; s++)
				{
					const int v0 = g_eac_modifier_table[T0][s] + a0;
					const int v1 = g_eac_modifier_table[T1][s] + a1;
					const int v2 = g_eac_modifier_table[T2][s] + a2;
					const int v3 = g_eac_modifier_table[T3][s] + a3;

					l0 = basisu::minimum(l0, (basisu::iabs(v0) << 3) | s);
					l1 = basisu::minimum(l1, (basisu::iabs(v1) << 3) | s);
					l2 = basisu::minimum(l2, (basisu::iabs(v2) << 3) | s);
					l3 = basisu::minimum(l3, (basisu::iabs(v3) << 3) | s);
				}
			}
			else
			{
				const int a0 = base[0] - a, a1 = base[1] - a, a2 = base[2] - a, a3 = base[3] - a;

				for (uint32_t s = 0; s < 8; s++)
				{
					const int v0 = mul[0] * g_eac_modifier_table[T0][s] + a0;
					const int v1 = mul[1] * g_eac_modifier_table[T1][s] + a1;
					const int v2 = mul[2] * g_eac_modifier_table[T2][s] + a2;
					const int v3 = mul[3] * g_eac_modifier_table[T3][s] + a3;

					l0 = basisu::minimum(l0, (basisu::iabs(v0) << 3) | s);
					l1 = basisu::minimum(l1, (basisu::iabs(v1) << 3) | s);
					l2 = basisu::minimum(l2, (basisu::iabs(v2) << 3) | s);
					l3 = basisu::minimum(l3, (basisu::iabs(v3) << 3) | s);
				}
			}

			sels[0][i] = l0 & 7;
			sels[1][i] = l1 & 7;
			sels[2][i] = l2 & 7;
			sels[3][i] = l3 & 7;

			total_err[0] += basisu::square<uint32_t>(l0 >> 3);
			total_err[1] += basisu::square<uint32_t>(l1 >> 3);
			total_err[2] += basisu::square<uint32_t>(l2 >> 3);
			total_err[3] += basisu::square<uint32_t>(l3 >> 3);
		}

		uint32_t min_err = total_err[0], min_index = 0;
		for (uint32_t i = 1; i < 4; i++)
		{
			if (total_err[i] < min_err)
			{
				min_err = total_err[i];
				min_index = i;
			}
		}

		blk.m_base = base[min_index];
		blk.m_multiplier = mul[min_index];
		blk.m_table = s_tables[min_index];

		uint64_t packed_sels = 0;
		const uint8_t* pSels = &sels[min_index][0];
		for (uint32_t i = 0; i < 16; i++)
			packed_sels |= (static_cast<uint64_t>(pSels[i]) << s_etc2_eac_bit_ofs[i]);

		blk.set_selector_bits(packed_sels);
	}

	// Checks all 16 tables. Around ~2 dB better vs. pack_eac(), ~1.2 dB less than near-optimal.
	static void pack_eac_high_quality(eac_block& blk, const uint8_t* pPixels, uint32_t stride)
	{
		uint32_t min_alpha = 255, max_alpha = 0;
		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t a = pPixels[i * stride];
			if (a < min_alpha) min_alpha = a;
			if (a > max_alpha) max_alpha = a;
		}

		if (min_alpha == max_alpha)
		{
			pack_eac_solid_block(blk, min_alpha);
			return;
		}

		const uint32_t alpha_range = max_alpha - min_alpha;

		const uint32_t SINGLE_TABLE_THRESH = 5;
		if (alpha_range <= SINGLE_TABLE_THRESH)
		{
			// If alpha_range <= 5 table 13 is lossless
			int base = clamp255((int)max_alpha - 2);

			blk.m_base = base;
			blk.m_multiplier = 1;
			blk.m_table = 13;

			base -= 3;

			uint64_t packed_sels = 0;
			for (uint32_t i = 0; i < 16; i++)
			{
				const int a = pPixels[i * stride];

				static const uint8_t s_sels[6] = { 2, 1, 0, 4, 5, 6 };

				int sel = a - base;
				assert(sel >= 0 && sel <= 5);

				packed_sels |= (static_cast<uint64_t>(s_sels[sel]) << s_etc2_eac_bit_ofs[i]);
			}

			blk.set_selector_bits(packed_sels);

			return;
		}

		int base[16], mul[16];
		for (uint32_t table = 0; table < 16; table++)
		{
			const float range = (float)(g_eac_modifier_table[table][ETC2_EAC_MAX_VALUE_SELECTOR] - g_eac_modifier_table[table][ETC2_EAC_MIN_VALUE_SELECTOR]);

			base[table] = clamp255((int)roundf(basisu::lerp((float)min_alpha, (float)max_alpha, (float)(0 - g_eac_modifier_table[table][ETC2_EAC_MIN_VALUE_SELECTOR]) / range)));
			mul[table] = clampi((int)roundf(alpha_range / range), 1, 15);
		}

		uint32_t total_err[16];
		memset(total_err, 0, sizeof(total_err));

		uint8_t sels[16][16];

		for (uint32_t table = 0; table < 16; table++)
		{
			const int8_t* pTable = &g_eac_modifier_table[table][0];
			const int m = mul[table], b = base[table];

			uint32_t prev_l = 0, prev_a = UINT32_MAX;

			for (uint32_t i = 0; i < 16; i++)
			{
				const int a = pPixels[i * stride];

				if ((uint32_t)a == prev_a)
				{
					sels[table][i] = prev_l & 7;
					total_err[table] += basisu::square<uint32_t>(prev_l >> 3);
				}
				else
				{
					uint32_t l = basisu::iabs(clamp255(m * pTable[0] + b) - a) << 3;
					l = basisu::minimum(l, (basisu::iabs(clamp255(m * pTable[1] + b) - a) << 3) | 1);
					l = basisu::minimum(l, (basisu::iabs(clamp255(m * pTable[2] + b) - a) << 3) | 2);
					l = basisu::minimum(l, (basisu::iabs(clamp255(m * pTable[3] + b) - a) << 3) | 3);
					l = basisu::minimum(l, (basisu::iabs(clamp255(m * pTable[4] + b) - a) << 3) | 4);
					l = basisu::minimum(l, (basisu::iabs(clamp255(m * pTable[5] + b) - a) << 3) | 5);
					l = basisu::minimum(l, (basisu::iabs(clamp255(m * pTable[6] + b) - a) << 3) | 6);
					l = basisu::minimum(l, (basisu::iabs(clamp255(m * pTable[7] + b) - a) << 3) | 7);

					sels[table][i] = l & 7;
					total_err[table] += basisu::square<uint32_t>(l >> 3);

					prev_l = l;
					prev_a = a;
				}
			}
		}

		uint32_t min_err = total_err[0], min_index = 0;
		for (uint32_t i = 1; i < 16; i++)
		{
			if (total_err[i] < min_err)
			{
				min_err = total_err[i];
				min_index = i;
			}
		}

		blk.m_base = base[min_index];
		blk.m_multiplier = mul[min_index];
		blk.m_table = min_index;

		uint64_t packed_sels = 0;
		const uint8_t* pSels = &sels[min_index][0];
		for (uint32_t i = 0; i < 16; i++)
			packed_sels |= (static_cast<uint64_t>(pSels[i]) << s_etc2_eac_bit_ofs[i]);

		blk.set_selector_bits(packed_sels);
	}

	bool transcode_uastc_to_etc2_eac_r11(const uastc_block& src_blk, void* pDst, bool high_quality, uint32_t chan0)
	{
		unpacked_uastc_block unpacked_src_blk;
		if (!unpack_uastc(src_blk, unpacked_src_blk, false))
			return false;

		const uint32_t mode = unpacked_src_blk.m_mode;

		if (mode == UASTC_MODE_INDEX_SOLID_COLOR)
		{
			pack_eac_solid_block(*static_cast<eac_block*>(pDst), unpacked_src_blk.m_solid_color.c[chan0]);
			return true;
		}

		color32 block_pixels[4][4];
		const bool unpack_srgb = false;
		if (!unpack_uastc(unpacked_src_blk, &block_pixels[0][0], unpack_srgb))
			return false;

		if (chan0 == 3)
			transcode_uastc_to_etc2_eac_a8(unpacked_src_blk, block_pixels, pDst);
		else
			(high_quality ? pack_eac_high_quality : pack_eac)(*static_cast<eac_block*>(pDst), &block_pixels[0][0].c[chan0], sizeof(color32));

		return true;
	}

	bool transcode_uastc_to_etc2_eac_rg11(const uastc_block& src_blk, void* pDst, bool high_quality, uint32_t chan0, uint32_t chan1)
	{
		unpacked_uastc_block unpacked_src_blk;
		if (!unpack_uastc(src_blk, unpacked_src_blk, false))
			return false;

		const uint32_t mode = unpacked_src_blk.m_mode;

		if (mode == UASTC_MODE_INDEX_SOLID_COLOR)
		{
			pack_eac_solid_block(static_cast<eac_block*>(pDst)[0], unpacked_src_blk.m_solid_color.c[chan0]);
			pack_eac_solid_block(static_cast<eac_block*>(pDst)[1], unpacked_src_blk.m_solid_color.c[chan1]);
			return true;
		}

		color32 block_pixels[4][4];
		const bool unpack_srgb = false;
		if (!unpack_uastc(unpacked_src_blk, &block_pixels[0][0], unpack_srgb))
			return false;

		if (chan0 == 3)
			transcode_uastc_to_etc2_eac_a8(unpacked_src_blk, block_pixels, &static_cast<eac_block*>(pDst)[0]);
		else
			(high_quality ? pack_eac_high_quality : pack_eac)(static_cast<eac_block*>(pDst)[0], &block_pixels[0][0].c[chan0], sizeof(color32));

		if (chan1 == 3)
			transcode_uastc_to_etc2_eac_a8(unpacked_src_blk, block_pixels, &static_cast<eac_block*>(pDst)[1]);
		else
			(high_quality ? pack_eac_high_quality : pack_eac)(static_cast<eac_block*>(pDst)[1], &block_pixels[0][0].c[chan1], sizeof(color32));
		return true;
	}

	// PVRTC1
	static void fixup_pvrtc1_4_modulation_rgb(
		const uastc_block* pSrc_blocks,
		const uint32_t* pPVRTC_endpoints,
		void* pDst_blocks,
		uint32_t num_blocks_x, uint32_t num_blocks_y, bool from_alpha)
	{
		const uint32_t x_mask = num_blocks_x - 1;
		const uint32_t y_mask = num_blocks_y - 1;
		const uint32_t x_bits = basisu::total_bits(x_mask);
		const uint32_t y_bits = basisu::total_bits(y_mask);
		const uint32_t min_bits = basisu::minimum(x_bits, y_bits);
		//const uint32_t max_bits = basisu::maximum(x_bits, y_bits);
		const uint32_t swizzle_mask = (1 << (min_bits * 2)) - 1;

		uint32_t block_index = 0;

		// really 3x3
		int e0[4][4], e1[4][4];

		for (int y = 0; y < static_cast<int>(num_blocks_y); y++)
		{
			const uint32_t* pE_rows[3];

			for (int ey = 0; ey < 3; ey++)
			{
				int by = y + ey - 1;

				const uint32_t* pE = &pPVRTC_endpoints[(by & y_mask) * num_blocks_x];

				pE_rows[ey] = pE;

				for (int ex = 0; ex < 3; ex++)
				{
					int bx = 0 + ex - 1;

					const uint32_t e = pE[bx & x_mask];

					e0[ex][ey] = (get_opaque_endpoint_l0(e) * 255) / 31;
					e1[ex][ey] = (get_opaque_endpoint_l1(e) * 255) / 31;
				}
			}

			const uint32_t y_swizzle = (g_pvrtc_swizzle_table[y >> 8] << 16) | g_pvrtc_swizzle_table[y & 0xFF];

			for (int x = 0; x < static_cast<int>(num_blocks_x); x++, block_index++)
			{
				const uastc_block& src_block = pSrc_blocks[block_index];

				color32 block_pixels[4][4];
				unpack_uastc(src_block, &block_pixels[0][0], false);
				if (from_alpha)
				{
					// Just set RGB to alpha to avoid adding complexity below.
					for (uint32_t i = 0; i < 16; i++)
					{
						const uint8_t a = ((color32*)block_pixels)[i].a;
						((color32*)block_pixels)[i].set(a, a, a, 255);
					}
				}

				const uint32_t x_swizzle = (g_pvrtc_swizzle_table[x >> 8] << 17) | (g_pvrtc_swizzle_table[x & 0xFF] << 1);

				uint32_t swizzled = x_swizzle | y_swizzle;
				if (num_blocks_x != num_blocks_y)
				{
					swizzled &= swizzle_mask;

					if (num_blocks_x > num_blocks_y)
						swizzled |= ((x >> min_bits) << (min_bits * 2));
					else
						swizzled |= ((y >> min_bits) << (min_bits * 2));
				}

				pvrtc4_block* pDst_block = static_cast<pvrtc4_block*>(pDst_blocks) + swizzled;
				pDst_block->m_endpoints = pPVRTC_endpoints[block_index];

				{
					const uint32_t ex = 2;
					int bx = x + ex - 1;
					bx &= x_mask;

#define DO_ROW(ey) \
					{ \
						const uint32_t e = pE_rows[ey][bx]; \
						e0[ex][ey] = (get_opaque_endpoint_l0(e) * 255) / 31; \
						e1[ex][ey] = (get_opaque_endpoint_l1(e) * 255) / 31; \
					}

					DO_ROW(0);
					DO_ROW(1);
					DO_ROW(2);
#undef DO_ROW
				}

				uint32_t mod = 0;

#define DO_PIX(lx, ly, w0, w1, w2, w3) \
				{ \
					int ca_l = a0 * w0 + a1 * w1 + a2 * w2 + a3 * w3; \
					int cb_l = b0 * w0 + b1 * w1 + b2 * w2 + b3 * w3; \
					int cl = (block_pixels[ly][lx].r + block_pixels[ly][lx].g + block_pixels[ly][lx].b) * 16; \
					int dl = cb_l - ca_l; \
					int vl = cl - ca_l; \
					int p = vl * 16; \
					if (ca_l > cb_l) { p = -p; dl = -dl; } \
					uint32_t m = 0; \
					if (p > 3 * dl) m = (uint32_t)(1 << ((ly) * 8 + (lx) * 2)); \
					if (p > 8 * dl) m = (uint32_t)(2 << ((ly) * 8 + (lx) * 2)); \
					if (p > 13 * dl) m = (uint32_t)(3 << ((ly) * 8 + (lx) * 2)); \
					mod |= m; \
				}

				{
					const uint32_t ex = 0, ey = 0;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(0, 0, 4, 4, 4, 4);
					DO_PIX(1, 0, 2, 6, 2, 6);
					DO_PIX(0, 1, 2, 2, 6, 6);
					DO_PIX(1, 1, 1, 3, 3, 9);
				}

				{
					const uint32_t ex = 1, ey = 0;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(2, 0, 8, 0, 8, 0);
					DO_PIX(3, 0, 6, 2, 6, 2);
					DO_PIX(2, 1, 4, 0, 12, 0);
					DO_PIX(3, 1, 3, 1, 9, 3);
				}

				{
					const uint32_t ex = 0, ey = 1;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(0, 2, 8, 8, 0, 0);
					DO_PIX(1, 2, 4, 12, 0, 0);
					DO_PIX(0, 3, 6, 6, 2, 2);
					DO_PIX(1, 3, 3, 9, 1, 3);
				}

				{
					const uint32_t ex = 1, ey = 1;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(2, 2, 16, 0, 0, 0);
					DO_PIX(3, 2, 12, 4, 0, 0);
					DO_PIX(2, 3, 12, 0, 4, 0);
					DO_PIX(3, 3, 9, 3, 3, 1);
				}
#undef DO_PIX

				pDst_block->m_modulation = mod;

				e0[0][0] = e0[1][0]; e0[1][0] = e0[2][0];
				e0[0][1] = e0[1][1]; e0[1][1] = e0[2][1];
				e0[0][2] = e0[1][2]; e0[1][2] = e0[2][2];

				e1[0][0] = e1[1][0]; e1[1][0] = e1[2][0];
				e1[0][1] = e1[1][1]; e1[1][1] = e1[2][1];
				e1[0][2] = e1[1][2]; e1[1][2] = e1[2][2];

			} // x
		} // y
	}

	static void fixup_pvrtc1_4_modulation_rgba(
		const uastc_block* pSrc_blocks,
		const uint32_t* pPVRTC_endpoints,
		void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y)
	{
		const uint32_t x_mask = num_blocks_x - 1;
		const uint32_t y_mask = num_blocks_y - 1;
		const uint32_t x_bits = basisu::total_bits(x_mask);
		const uint32_t y_bits = basisu::total_bits(y_mask);
		const uint32_t min_bits = basisu::minimum(x_bits, y_bits);
		//const uint32_t max_bits = basisu::maximum(x_bits, y_bits);
		const uint32_t swizzle_mask = (1 << (min_bits * 2)) - 1;

		uint32_t block_index = 0;

		// really 3x3
		int e0[4][4], e1[4][4];

		for (int y = 0; y < static_cast<int>(num_blocks_y); y++)
		{
			const uint32_t* pE_rows[3];

			for (int ey = 0; ey < 3; ey++)
			{
				int by = y + ey - 1;

				const uint32_t* pE = &pPVRTC_endpoints[(by & y_mask) * num_blocks_x];

				pE_rows[ey] = pE;

				for (int ex = 0; ex < 3; ex++)
				{
					int bx = 0 + ex - 1;

					const uint32_t e = pE[bx & x_mask];

					e0[ex][ey] = get_endpoint_l8(e, 0);
					e1[ex][ey] = get_endpoint_l8(e, 1);
				}
			}

			const uint32_t y_swizzle = (g_pvrtc_swizzle_table[y >> 8] << 16) | g_pvrtc_swizzle_table[y & 0xFF];

			for (int x = 0; x < static_cast<int>(num_blocks_x); x++, block_index++)
			{
				const uastc_block& src_block = pSrc_blocks[block_index];

				color32 block_pixels[4][4];
				unpack_uastc(src_block, &block_pixels[0][0], false);

				const uint32_t x_swizzle = (g_pvrtc_swizzle_table[x >> 8] << 17) | (g_pvrtc_swizzle_table[x & 0xFF] << 1);

				uint32_t swizzled = x_swizzle | y_swizzle;
				if (num_blocks_x != num_blocks_y)
				{
					swizzled &= swizzle_mask;

					if (num_blocks_x > num_blocks_y)
						swizzled |= ((x >> min_bits) << (min_bits * 2));
					else
						swizzled |= ((y >> min_bits) << (min_bits * 2));
				}

				pvrtc4_block* pDst_block = static_cast<pvrtc4_block*>(pDst_blocks) + swizzled;
				pDst_block->m_endpoints = pPVRTC_endpoints[block_index];

				{
					const uint32_t ex = 2;
					int bx = x + ex - 1;
					bx &= x_mask;

#define DO_ROW(ey) \
					{ \
						const uint32_t e = pE_rows[ey][bx]; \
						e0[ex][ey] = get_endpoint_l8(e, 0); \
						e1[ex][ey] = get_endpoint_l8(e, 1); \
					}

					DO_ROW(0);
					DO_ROW(1);
					DO_ROW(2);
#undef DO_ROW
				}

				uint32_t mod = 0;

#define DO_PIX(lx, ly, w0, w1, w2, w3) \
				{ \
					int ca_l = a0 * w0 + a1 * w1 + a2 * w2 + a3 * w3; \
					int cb_l = b0 * w0 + b1 * w1 + b2 * w2 + b3 * w3; \
					int cl = 16 * (block_pixels[ly][lx].r + block_pixels[ly][lx].g + block_pixels[ly][lx].b + block_pixels[ly][lx].a); \
					int dl = cb_l - ca_l; \
					int vl = cl - ca_l; \
					int p = vl * 16; \
					if (ca_l > cb_l) { p = -p; dl = -dl; } \
					uint32_t m = 0; \
					if (p > 3 * dl) m = (uint32_t)(1 << ((ly) * 8 + (lx) * 2)); \
					if (p > 8 * dl) m = (uint32_t)(2 << ((ly) * 8 + (lx) * 2)); \
					if (p > 13 * dl) m = (uint32_t)(3 << ((ly) * 8 + (lx) * 2)); \
					mod |= m; \
				}

				{
					const uint32_t ex = 0, ey = 0;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(0, 0, 4, 4, 4, 4);
					DO_PIX(1, 0, 2, 6, 2, 6);
					DO_PIX(0, 1, 2, 2, 6, 6);
					DO_PIX(1, 1, 1, 3, 3, 9);
				}

				{
					const uint32_t ex = 1, ey = 0;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(2, 0, 8, 0, 8, 0);
					DO_PIX(3, 0, 6, 2, 6, 2);
					DO_PIX(2, 1, 4, 0, 12, 0);
					DO_PIX(3, 1, 3, 1, 9, 3);
				}

				{
					const uint32_t ex = 0, ey = 1;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(0, 2, 8, 8, 0, 0);
					DO_PIX(1, 2, 4, 12, 0, 0);
					DO_PIX(0, 3, 6, 6, 2, 2);
					DO_PIX(1, 3, 3, 9, 1, 3);
				}

				{
					const uint32_t ex = 1, ey = 1;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(2, 2, 16, 0, 0, 0);
					DO_PIX(3, 2, 12, 4, 0, 0);
					DO_PIX(2, 3, 12, 0, 4, 0);
					DO_PIX(3, 3, 9, 3, 3, 1);
				}
#undef DO_PIX

				pDst_block->m_modulation = mod;

				e0[0][0] = e0[1][0]; e0[1][0] = e0[2][0];
				e0[0][1] = e0[1][1]; e0[1][1] = e0[2][1];
				e0[0][2] = e0[1][2]; e0[1][2] = e0[2][2];

				e1[0][0] = e1[1][0]; e1[1][0] = e1[2][0];
				e1[0][1] = e1[1][1]; e1[1][1] = e1[2][1];
				e1[0][2] = e1[1][2]; e1[1][2] = e1[2][2];

			} // x
		} // y
	}

	bool transcode_uastc_to_pvrtc1_4_rgb(const uastc_block* pSrc_blocks, void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y, bool high_quality, bool from_alpha)
	{
		BASISU_NOTE_UNUSED(high_quality);

		if ((!num_blocks_x) || (!num_blocks_y))
			return false;

		const uint32_t width = num_blocks_x * 4;
		const uint32_t height = num_blocks_y * 4;
		if (!basisu::is_pow2(width) || !basisu::is_pow2(height))
			return false;

		basisu::vector<uint32_t> temp_endpoints(num_blocks_x * num_blocks_y);

		for (uint32_t y = 0; y < num_blocks_y; y++)
		{
			for (uint32_t x = 0; x < num_blocks_x; x++)
			{
				color32 block_pixels[16];
				if (!unpack_uastc(pSrc_blocks[x + y * num_blocks_x], block_pixels, false))
					return false;

				// Get block's RGB bounding box 
				color32 low_color(255, 255, 255, 255), high_color(0, 0, 0, 0);

				if (from_alpha)
				{
					uint32_t low_a = 255, high_a = 0;
					for (uint32_t i = 0; i < 16; i++)
					{
						low_a = basisu::minimum<uint32_t>(low_a, block_pixels[i].a);
						high_a = basisu::maximum<uint32_t>(high_a, block_pixels[i].a);
					}
					low_color.set(low_a, low_a, low_a, 255);
					high_color.set(high_a, high_a, high_a, 255);
				}
				else
				{
					for (uint32_t i = 0; i < 16; i++)
					{
						low_color = color32::comp_min(low_color, block_pixels[i]);
						high_color = color32::comp_max(high_color, block_pixels[i]);
					}
				}

				// Set PVRTC1 endpoints to floor/ceil of bounding box's coordinates.
				pvrtc4_block temp;
				temp.set_opaque_endpoint_floor(0, low_color);
				temp.set_opaque_endpoint_ceil(1, high_color);

				temp_endpoints[x + y * num_blocks_x] = temp.m_endpoints;
			}
		}

		fixup_pvrtc1_4_modulation_rgb(pSrc_blocks, &temp_endpoints[0], pDst_blocks, num_blocks_x, num_blocks_y, from_alpha);

		return true;
	}

	bool transcode_uastc_to_pvrtc1_4_rgba(const uastc_block* pSrc_blocks, void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y, bool high_quality)
	{
		BASISU_NOTE_UNUSED(high_quality);

		if ((!num_blocks_x) || (!num_blocks_y))
			return false;

		const uint32_t width = num_blocks_x * 4;
		const uint32_t height = num_blocks_y * 4;
		if (!basisu::is_pow2(width) || !basisu::is_pow2(height))
			return false;

		basisu::vector<uint32_t> temp_endpoints(num_blocks_x * num_blocks_y);

		for (uint32_t y = 0; y < num_blocks_y; y++)
		{
			for (uint32_t x = 0; x < num_blocks_x; x++)
			{
				color32 block_pixels[16];
				if (!unpack_uastc(pSrc_blocks[x + y * num_blocks_x], block_pixels, false))
					return false;

				// Get block's RGBA bounding box 
				color32 low_color(255, 255, 255, 255), high_color(0, 0, 0, 0);

				for (uint32_t i = 0; i < 16; i++)
				{
					low_color = color32::comp_min(low_color, block_pixels[i]);
					high_color = color32::comp_max(high_color, block_pixels[i]);
				}

				// Set PVRTC1 endpoints to floor/ceil of bounding box's coordinates.
				pvrtc4_block temp;
				temp.set_endpoint_floor(0, low_color);
				temp.set_endpoint_ceil(1, high_color);

				temp_endpoints[x + y * num_blocks_x] = temp.m_endpoints;
			}
		}

		fixup_pvrtc1_4_modulation_rgba(pSrc_blocks, &temp_endpoints[0], pDst_blocks, num_blocks_x, num_blocks_y);

		return true;
	}

	void uastc_init()
	{
		for (uint32_t range = 0; range < BC7ENC_TOTAL_ASTC_RANGES; range++)
		{
			if (!astc_is_valid_endpoint_range(range))
				continue;

			const uint32_t levels = astc_get_levels(range);

			uint32_t vals[256];
			for (uint32_t i = 0; i < levels; i++)
				vals[i] = (unquant_astc_endpoint_val(i, range) << 8) | i;

			std::sort(vals, vals + levels);

			for (uint32_t i = 0; i < levels; i++)
			{
				const uint32_t order = vals[i] & 0xFF;
				const uint32_t unq = vals[i] >> 8;

				g_astc_unquant[range][order].m_unquant = (uint8_t)unq;
				g_astc_unquant[range][order].m_index = (uint8_t)i;

			} // i
		}

		// TODO: Precompute?
		// BC7 777.1
		for (int c = 0; c < 256; c++)
		{
			for (uint32_t lp = 0; lp < 2; lp++)
			{
				endpoint_err best;
				best.m_error = (uint16_t)UINT16_MAX;

				for (uint32_t l = 0; l < 128; l++)
				{
					const uint32_t low = (l << 1) | lp;

					for (uint32_t h = 0; h < 128; h++)
					{
						const uint32_t high = (h << 1) | lp;

						const int k = (low * (64 - g_bc7_weights4[BC7ENC_MODE_6_OPTIMAL_INDEX]) + high * g_bc7_weights4[BC7ENC_MODE_6_OPTIMAL_INDEX] + 32) >> 6;

						const int err = (k - c) * (k - c);
						if (err < best.m_error)
						{
							best.m_error = (uint16_t)err;
							best.m_lo = (uint8_t)l;
							best.m_hi = (uint8_t)h;
						}
					} // h
				} // l

				g_bc7_mode_6_optimal_endpoints[c][lp] = best;
			} // lp

		} // c

		// BC7 777
		for (int c = 0; c < 256; c++)
		{
			endpoint_err best;
			best.m_error = (uint16_t)UINT16_MAX;

			for (uint32_t l = 0; l < 128; l++)
			{
				const uint32_t low = (l << 1) | (l >> 6);

				for (uint32_t h = 0; h < 128; h++)
				{
					const uint32_t high = (h << 1) | (h >> 6);

					const int k = (low * (64 - g_bc7_weights2[BC7ENC_MODE_5_OPTIMAL_INDEX]) + high * g_bc7_weights2[BC7ENC_MODE_5_OPTIMAL_INDEX] + 32) >> 6;

					const int err = (k - c) * (k - c);
					if (err < best.m_error)
					{
						best.m_error = (uint16_t)err;
						best.m_lo = (uint8_t)l;
						best.m_hi = (uint8_t)h;
					}
				} // h
			} // l

			g_bc7_mode_5_optimal_endpoints[c] = best;

		} // c
	}

#endif // #if BASISD_SUPPORT_UASTC

// ------------------------------------------------------------------------------------------------------ 
// KTX2
// ------------------------------------------------------------------------------------------------------ 

#if BASISD_SUPPORT_KTX2
	const uint8_t g_ktx2_file_identifier[12] = { 0xAB, 0x4B, 0x54, 0x58, 0x20, 0x32, 0x30, 0xBB, 0x0D, 0x0A, 0x1A, 0x0A };

	ktx2_transcoder::ktx2_transcoder() :
		m_etc1s_transcoder()
	{
		clear();
	}

	void ktx2_transcoder::clear()
	{
		m_pData = nullptr;
		m_data_size = 0;

		memset((void *)&m_header, 0, sizeof(m_header));
		m_levels.clear();
		m_dfd.clear();
		m_key_values.clear();
		memset((void *)&m_etc1s_header, 0, sizeof(m_etc1s_header));
		m_etc1s_image_descs.clear();
		m_astc_6x6_intermediate_image_descs.clear();
				
		m_format = basist::basis_tex_format::cETC1S;

		m_dfd_color_model = 0;
		m_dfd_color_prims = KTX2_DF_PRIMARIES_UNSPECIFIED;
		m_dfd_transfer_func = 0;
		m_dfd_flags = 0;
		m_dfd_samples = 0;
		m_dfd_chan0 = KTX2_DF_CHANNEL_UASTC_RGB;
		m_dfd_chan1 = KTX2_DF_CHANNEL_UASTC_RGB;

		m_etc1s_transcoder.clear();
				
		m_def_transcoder_state.clear();
		
		m_has_alpha = false;
		m_is_video = false;
		m_ldr_hdr_upconversion_nit_multiplier = 0.0f;
	}

	bool ktx2_transcoder::init(const void* pData, uint32_t data_size)
	{
		clear();

		if (!pData)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: pData is nullptr\n");
			assert(0);
			return false;
		}

		if (data_size <= sizeof(ktx2_header))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: File is impossibly too small to be a valid KTX2 file\n");
			return false;
		}

		if (memcmp(pData, g_ktx2_file_identifier, sizeof(g_ktx2_file_identifier)) != 0)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: KTX2 file identifier is not present\n");
			return false;
		}

		m_pData = static_cast<const uint8_t *>(pData);
		m_data_size = data_size;

		memcpy((void *)&m_header, pData, sizeof(m_header));

		// Check for supported VK formats. We may also need to parse the DFD.
		if ((m_header.m_vk_format != KTX2_VK_FORMAT_UNDEFINED) && 
			(m_header.m_vk_format != basist::KTX2_FORMAT_ASTC_4x4_SFLOAT_BLOCK) && 
			(m_header.m_vk_format != basist::KTX2_FORMAT_ASTC_6x6_SFLOAT_BLOCK))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: KTX2 file must be in ETC1S or UASTC LDR/HDR format\n");
			return false;
		}

		// 3.3: "When format is VK_FORMAT_UNDEFINED, typeSize must equal 1."
		if (m_header.m_type_size != 1)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid type_size\n");
			return false;
		}

		// We only currently support 2D textures (plain, cubemapped, or texture array), which is by far the most common use case.
		// The BasisU library does not support 1D or 3D textures at all.
		if ((m_header.m_pixel_width < 1) || (m_header.m_pixel_height < 1) || (m_header.m_pixel_depth > 0))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Only 2D or cubemap textures are supported\n");
			return false;
		}

		// Face count must be 1 or 6
		if ((m_header.m_face_count != 1) && (m_header.m_face_count != 6))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid face count, file is corrupted or invalid\n");
			return false;
		}

		if (m_header.m_face_count > 1)
		{
			// 3.4: Make sure cubemaps are square.
			if (m_header.m_pixel_width != m_header.m_pixel_height)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Cubemap is not square\n");
				return false;
			}
		}
		
		// 3.7 levelCount: "levelCount=0 is allowed, except for block-compressed formats"
		if (m_header.m_level_count < 1)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid level count\n");
			return false;
		}

		// Sanity check the level count.
		if (m_header.m_level_count > KTX2_MAX_SUPPORTED_LEVEL_COUNT)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Too many levels or file is corrupted or invalid\n");
			return false;
		}

		if (m_header.m_supercompression_scheme > KTX2_SS_ZSTANDARD)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid/unsupported supercompression or file is corrupted or invalid\n");
			return false;
		}

		if (m_header.m_supercompression_scheme == KTX2_SS_BASISLZ)
		{
#if 0
			if (m_header.m_sgd_byte_length <= sizeof(ktx2_etc1s_global_data_header))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Supercompression global data is too small\n");
				return false;
			}
#endif

			if (m_header.m_sgd_byte_offset.get_uint64() < sizeof(ktx2_header))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Supercompression global data offset is too low\n");
				return false;
			}

			if (m_header.m_sgd_byte_offset.get_uint64() + m_header.m_sgd_byte_length.get_uint64() > m_data_size)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Supercompression global data offset and/or length is too high\n");
				return false;
			}
		}

		if (!m_levels.try_resize(m_header.m_level_count))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Out of memory\n");
			return false;
		}

		const uint32_t level_index_size_in_bytes = basisu::maximum(1U, (uint32_t)m_header.m_level_count) * sizeof(ktx2_level_index);

		if ((sizeof(ktx2_header) + level_index_size_in_bytes) > m_data_size)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: File is too small (can't read level index array)\n");
			return false;
		}

		memcpy((void *)&m_levels[0], m_pData + sizeof(ktx2_header), level_index_size_in_bytes);
		
		// Sanity check the level offsets and byte sizes
		for (uint32_t i = 0; i < m_levels.size(); i++)
		{
			if (m_levels[i].m_byte_offset.get_uint64() < sizeof(ktx2_header))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid level offset (too low)\n");
				return false;
			}

			if (!m_levels[i].m_byte_length.get_uint64())
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid level byte length\n");
			}

			if ((m_levels[i].m_byte_offset.get_uint64() + m_levels[i].m_byte_length.get_uint64()) > m_data_size)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid level offset and/or length\n");
				return false;
			}
			
			const uint64_t MAX_SANE_LEVEL_UNCOMP_SIZE = 2048ULL * 1024ULL * 1024ULL;
			
			if (m_levels[i].m_uncompressed_byte_length.get_uint64() >= MAX_SANE_LEVEL_UNCOMP_SIZE)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid level offset (too large)\n");
				return false;
			}

			if (m_header.m_supercompression_scheme == KTX2_SS_BASISLZ)
			{
				if (m_levels[i].m_uncompressed_byte_length.get_uint64())
				{
					BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid uncompressed length (0)\n");
					return false;
				}
			}
			else if (m_header.m_supercompression_scheme >= KTX2_SS_ZSTANDARD)
			{
				if (!m_levels[i].m_uncompressed_byte_length.get_uint64())
				{
					BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid uncompressed length (1)\n");
					return false;
				}
			}
		}

		const uint32_t DFD_MINIMUM_SIZE = 44, DFD_MAXIMUM_SIZE = 60;
		if ((m_header.m_dfd_byte_length != DFD_MINIMUM_SIZE) && (m_header.m_dfd_byte_length != DFD_MAXIMUM_SIZE))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Unsupported DFD size\n");
			return false;
		}

		if (((m_header.m_dfd_byte_offset + m_header.m_dfd_byte_length) > m_data_size) || (m_header.m_dfd_byte_offset < sizeof(ktx2_header)))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid DFD offset and/or length\n");
			return false;
		}
				
		const uint8_t* pDFD = m_pData + m_header.m_dfd_byte_offset;

		if (!m_dfd.try_resize(m_header.m_dfd_byte_length))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Out of memory\n");
			return false;
		}

		memcpy(m_dfd.data(), pDFD, m_header.m_dfd_byte_length);
		
		// This is all hard coded for only ETC1S and UASTC.
		uint32_t dfd_total_size = basisu::read_le_dword(pDFD);
		
		// 3.10.3: Sanity check
		if (dfd_total_size != m_header.m_dfd_byte_length)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: DFD size validation failed (1)\n");
			return false;
		}
				
		// 3.10.3: More sanity checking
		if (m_header.m_kvd_byte_length)
		{
			if (dfd_total_size != m_header.m_kvd_byte_offset - m_header.m_dfd_byte_offset)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: DFD size validation failed (2)\n");
				return false;
			}
		}

		const uint32_t dfd_bits = basisu::read_le_dword(pDFD + 3 * sizeof(uint32_t));
		const uint32_t sample_channel0 = basisu::read_le_dword(pDFD + 7 * sizeof(uint32_t));
		 
		m_dfd_color_model = dfd_bits & 255;
		m_dfd_color_prims = (ktx2_df_color_primaries)((dfd_bits >> 8) & 255);
		m_dfd_transfer_func = (dfd_bits >> 16) & 255;
		m_dfd_flags = (dfd_bits >> 24) & 255;

		// See 3.10.1.Restrictions
		if ((m_dfd_transfer_func != KTX2_KHR_DF_TRANSFER_LINEAR) && (m_dfd_transfer_func != KTX2_KHR_DF_TRANSFER_SRGB))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid DFD transfer function\n");
			return false;
		}

		if (m_dfd_color_model == KTX2_KDF_DF_MODEL_ETC1S)
		{
			if (m_header.m_vk_format != basist::KTX2_VK_FORMAT_UNDEFINED)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid header vkFormat\n");
				return false;
			}

			m_format = basist::basis_tex_format::cETC1S;
			
			// 3.10.2: "Whether the image has 1 or 2 slices can be determined from the DFD's sample count."
			// If m_has_alpha is true it may be 2-channel RRRG or 4-channel RGBA, but we let the caller deal with that.
			m_has_alpha = (m_header.m_dfd_byte_length == 60);
			
			m_dfd_samples = m_has_alpha ? 2 : 1;
			m_dfd_chan0 = (ktx2_df_channel_id)((sample_channel0 >> 24) & 15);

			if (m_has_alpha)
			{
				const uint32_t sample_channel1 = basisu::read_le_dword(pDFD + 11 * sizeof(uint32_t));
				m_dfd_chan1 = (ktx2_df_channel_id)((sample_channel1 >> 24) & 15);
			}
		}
		else if (m_dfd_color_model == KTX2_KDF_DF_MODEL_UASTC_LDR_4X4)
		{
			if (m_header.m_vk_format != basist::KTX2_VK_FORMAT_UNDEFINED)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid header vkFormat\n");
				return false;
			}

			m_format = basist::basis_tex_format::cUASTC4x4;

			m_dfd_samples = 1;
			m_dfd_chan0 = (ktx2_df_channel_id)((sample_channel0 >> 24) & 15);
			
			// We're assuming "DATA" means RGBA so it has alpha.
			m_has_alpha = (m_dfd_chan0 == KTX2_DF_CHANNEL_UASTC_RGBA) || (m_dfd_chan0 == KTX2_DF_CHANNEL_UASTC_RRRG);
		}
		else if (m_dfd_color_model == KTX2_KDF_DF_MODEL_UASTC_HDR_4X4)
		{
			// UASTC HDR 4x4 is standard ASTC HDR 4x4 texture data. Check the header's vkFormat.
			if (m_header.m_vk_format != basist::KTX2_FORMAT_ASTC_4x4_SFLOAT_BLOCK)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid header vkFormat\n");
				return false;
			}

			m_format = basist::basis_tex_format::cUASTC_HDR_4x4;

			m_dfd_samples = 1;
			m_dfd_chan0 = (ktx2_df_channel_id)((sample_channel0 >> 24) & 15);

			// We're assuming "DATA" means RGBA so it has alpha.
			// [11/26/2024] - changed to always false for now
			m_has_alpha = false;// (m_dfd_chan0 == KTX2_DF_CHANNEL_UASTC_RGBA) || (m_dfd_chan0 == KTX2_DF_CHANNEL_UASTC_RRRG);
		}
		else if (m_dfd_color_model == KTX2_KDF_DF_MODEL_ASTC)
		{
			// The DFD indicates plain ASTC texture data. We only support ASTC HDR 6x6 - check the header's vkFormat.
			if (m_header.m_vk_format != basist::KTX2_FORMAT_ASTC_6x6_SFLOAT_BLOCK)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: DVD color model is ASTC, but the header's vkFormat isn't KTX2_FORMAT_ASTC_6x6_SFLOAT_BLOCK\n");
				return false;
			}

			m_format = basist::basis_tex_format::cASTC_HDR_6x6;

			m_dfd_samples = 1;
			m_dfd_chan0 = (ktx2_df_channel_id)((sample_channel0 >> 24) & 15);

			m_has_alpha = false;
		}
		else if (m_dfd_color_model == KTX2_KDF_DF_MODEL_ASTC_HDR_6X6_INTERMEDIATE)
		{
			// Custom variable block size ASTC HDR 6x6 texture data.
			if (m_header.m_vk_format != basist::KTX2_VK_FORMAT_UNDEFINED)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid header vkFormat\n");
				return false;
			}

			m_format = basist::basis_tex_format::cASTC_HDR_6x6_INTERMEDIATE;

			m_dfd_samples = 1;
			m_dfd_chan0 = (ktx2_df_channel_id)((sample_channel0 >> 24) & 15);

			m_has_alpha = false;
		}
		else
		{
			// Unsupported DFD color model.
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Unsupported DFD color model\n");
			return false;
		}
				
		if (!read_key_values())
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: read_key_values() failed\n");
			return false;
		}

		// Check for a KTXanimData key
		for (uint32_t i = 0; i < m_key_values.size(); i++)
		{
			if (strcmp(reinterpret_cast<const char*>(m_key_values[i].m_key.data()), "KTXanimData") == 0)
			{
				m_is_video = true;
				break;
			}
		}

		m_ldr_hdr_upconversion_nit_multiplier = 0.0f;

		for (uint32_t i = 0; i < m_key_values.size(); i++)
		{
			if (strcmp(reinterpret_cast<const char*>(m_key_values[i].m_key.data()), "LDRUpconversionMultiplier") == 0)
			{
				m_ldr_hdr_upconversion_nit_multiplier = (float)atof(reinterpret_cast<const char*>(m_key_values[i].m_value.data()));

				if (std::isnan(m_ldr_hdr_upconversion_nit_multiplier) || std::isinf(m_ldr_hdr_upconversion_nit_multiplier) || (m_ldr_hdr_upconversion_nit_multiplier < 0.0f))
					m_ldr_hdr_upconversion_nit_multiplier = 0;

				break;
			}
		}

		return true;
	}

	uint32_t ktx2_transcoder::get_etc1s_image_descs_image_flags(uint32_t level_index, uint32_t layer_index, uint32_t face_index) const
	{
		const uint32_t etc1s_image_index =
			(level_index * basisu::maximum<uint32_t>(m_header.m_layer_count, 1) * m_header.m_face_count) +
			layer_index * m_header.m_face_count +
			face_index;

		if (etc1s_image_index >= get_etc1s_image_descs().size())
		{
			assert(0);
			return 0;
		}

		return get_etc1s_image_descs()[etc1s_image_index].m_image_flags;
	}

	const basisu::uint8_vec* ktx2_transcoder::find_key(const std::string& key_name) const
	{
		for (uint32_t i = 0; i < m_key_values.size(); i++)
			if (strcmp((const char *)m_key_values[i].m_key.data(), key_name.c_str()) == 0)
				return &m_key_values[i].m_value;

		return nullptr;
	}
	
	bool ktx2_transcoder::start_transcoding()
	{
		if (!m_pData)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::start_transcoding: Must call init() first\n");
			return false;
		}

		if (m_header.m_supercompression_scheme == KTX2_SS_BASISLZ) 
		{
			if (m_format == basis_tex_format::cETC1S)
			{
				// Check if we've already decompressed the ETC1S global data. If so don't unpack it again.
				if (!m_etc1s_transcoder.get_endpoints().empty())
					return true;
				 
				if (!decompress_etc1s_global_data())
				{
					BASISU_DEVEL_ERROR("ktx2_transcoder::start_transcoding: decompress_etc1s_global_data() failed\n");
					return false;
				}

				if (!m_is_video)
				{
					// See if there are any P-frames. If so it must be a video, even if there wasn't a KTXanimData key.
					// Video cannot be a cubemap, and it must be a texture array.
					if ((m_header.m_face_count == 1) && (m_header.m_layer_count > 1))
					{
						for (uint32_t i = 0; i < m_etc1s_image_descs.size(); i++)
						{
							if (m_etc1s_image_descs[i].m_image_flags & KTX2_IMAGE_IS_P_FRAME)
							{
								m_is_video = true;
								break;
							}
						}
					}
				}
			}
			else if (m_format == basis_tex_format::cASTC_HDR_6x6_INTERMEDIATE)
			{
				if (m_astc_6x6_intermediate_image_descs.size())
					return true;

				if (!read_astc_6x6_hdr_intermediate_global_data())
				{
					BASISU_DEVEL_ERROR("ktx2_transcoder::start_transcoding: read_astc_6x6_hdr_intermediate_global_data() failed\n");
					return false;
				}
			}
			else
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::start_transcoding: Invalid supercompression scheme and/or format\n");
				return false;
			}
		}
		else if (m_header.m_supercompression_scheme == KTX2_SS_ZSTANDARD)
		{
#if !BASISD_SUPPORT_KTX2_ZSTD
			BASISU_DEVEL_ERROR("ktx2_transcoder::start_transcoding: File uses zstd supercompression, but zstd support was not enabled at compilation time (BASISD_SUPPORT_KTX2_ZSTD == 0)\n");
			return false;
#endif
		}

		return true;
	}

	bool ktx2_transcoder::get_image_level_info(ktx2_image_level_info& level_info, uint32_t level_index, uint32_t layer_index, uint32_t face_index) const
	{
		if (level_index >= m_levels.size())
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::get_image_level_info: level_index >= m_levels.size()\n");
			return false;
		}

		if (m_header.m_face_count > 1)
		{
			if (face_index >= 6)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::get_image_level_info: face_index >= 6\n");
				return false;
			}
		}
		else if (face_index != 0)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::get_image_level_info: face_index != 0\n");
			return false;
		}

		if (layer_index >= basisu::maximum<uint32_t>(m_header.m_layer_count, 1))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::get_image_level_info: layer_index >= maximum<uint32_t>(m_header.m_layer_count, 1)\n");
			return false;
		}
				
		const uint32_t level_width = basisu::maximum<uint32_t>(m_header.m_pixel_width >> level_index, 1);
		const uint32_t level_height = basisu::maximum<uint32_t>(m_header.m_pixel_height >> level_index, 1);

		const uint32_t block_width = get_block_width();
		const uint32_t block_height = get_block_height();

		const uint32_t num_blocks_x = (level_width + block_width - 1) / block_width;
		const uint32_t num_blocks_y = (level_height + block_height - 1) / block_height;

		level_info.m_face_index = face_index;
		level_info.m_layer_index = layer_index;
		level_info.m_level_index = level_index;
		level_info.m_orig_width = level_width;
		level_info.m_orig_height = level_height;
		level_info.m_width = num_blocks_x * block_width;
		level_info.m_height = num_blocks_y * block_height;
		level_info.m_block_width = block_width;
		level_info.m_block_height = block_height;
		level_info.m_num_blocks_x = num_blocks_x;
		level_info.m_num_blocks_y = num_blocks_y;
		level_info.m_total_blocks = num_blocks_x * num_blocks_y;
		level_info.m_alpha_flag = m_has_alpha;
		level_info.m_iframe_flag = false;
		
		if (m_etc1s_image_descs.size())
		{
			const uint32_t etc1s_image_index =
				(level_index * basisu::maximum<uint32_t>(m_header.m_layer_count, 1) * m_header.m_face_count) +
				layer_index * m_header.m_face_count +
				face_index;

			level_info.m_iframe_flag = (m_etc1s_image_descs[etc1s_image_index].m_image_flags & KTX2_IMAGE_IS_P_FRAME) == 0;
		}

		return true;
	}
		
	bool ktx2_transcoder::transcode_image_level(
		uint32_t level_index, uint32_t layer_index, uint32_t face_index, 
		void* pOutput_blocks, uint32_t output_blocks_buf_size_in_blocks_or_pixels,
		basist::transcoder_texture_format fmt,
		uint32_t decode_flags, uint32_t output_row_pitch_in_blocks_or_pixels, uint32_t output_rows_in_pixels, int channel0, int channel1,
		ktx2_transcoder_state* pState)
	{
		if (!m_pData)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_2D: Must call init() first\n");
			return false;
		}

		if (!pState)
			pState = &m_def_transcoder_state;
										
		if (level_index >= m_levels.size())
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_2D: level_index >= m_levels.size()\n");
			return false;
		}

		if (m_header.m_face_count > 1)
		{
			if (face_index >= 6)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_2D: face_index >= 6\n");
				return false;
			}
		}
		else if (face_index != 0)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_2D: face_index != 0\n");
			return false;
		}

		if (layer_index >= basisu::maximum<uint32_t>(m_header.m_layer_count, 1))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_2D: layer_index >= maximum<uint32_t>(m_header.m_layer_count, 1)\n");
			return false;
		}

		const uint8_t* pComp_level_data = m_pData + m_levels[level_index].m_byte_offset.get_uint64();
		uint64_t comp_level_data_size = m_levels[level_index].m_byte_length.get_uint64();
		
		const uint8_t* pUncomp_level_data = pComp_level_data;
		uint64_t uncomp_level_data_size = comp_level_data_size;

		if (uncomp_level_data_size > UINT32_MAX)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_2D: uncomp_level_data_size > UINT32_MAX\n");
			return false;
		}
				
		if (m_header.m_supercompression_scheme == KTX2_SS_ZSTANDARD)
		{
			// Check if we've already decompressed this level's supercompressed data.
			if ((int)level_index != pState->m_uncomp_data_level_index)
			{
				// Uncompress the entire level's supercompressed data.
				if (!decompress_level_data(level_index, pState->m_level_uncomp_data))
				{
					BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_2D: decompress_level_data() failed\n");
					return false;
				}
				pState->m_uncomp_data_level_index = level_index;
			}

			pUncomp_level_data = pState->m_level_uncomp_data.data();
			uncomp_level_data_size = pState->m_level_uncomp_data.size();
		}
				
		const uint32_t level_width = basisu::maximum<uint32_t>(m_header.m_pixel_width >> level_index, 1);
		const uint32_t level_height = basisu::maximum<uint32_t>(m_header.m_pixel_height >> level_index, 1);
		const uint32_t num_blocks4_x = (level_width + 3) >> 2;
		const uint32_t num_blocks4_y = (level_height + 3) >> 2;
		
		if (m_format == basist::basis_tex_format::cETC1S)
		{
			// Ensure start_transcoding() was called.
			if (m_etc1s_transcoder.get_endpoints().empty())
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_2D: must call start_transcoding() first\n");
				return false;
			}

			const uint32_t etc1s_image_index =
				(level_index * basisu::maximum<uint32_t>(m_header.m_layer_count, 1) * m_header.m_face_count) +
				layer_index * m_header.m_face_count +
				face_index;
		
			// Sanity check
			if (etc1s_image_index >= m_etc1s_image_descs.size())
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_2D: etc1s_image_index >= m_etc1s_image_descs.size()\n");
				assert(0);
				return false;
			}

			const ktx2_etc1s_image_desc& image_desc = m_etc1s_image_descs[etc1s_image_index];

			if (!m_etc1s_transcoder.transcode_image(fmt,
				pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, m_pData, m_data_size,
				num_blocks4_x, num_blocks4_y, level_width, level_height,
				level_index,
				m_levels[level_index].m_byte_offset.get_uint64() + image_desc.m_rgb_slice_byte_offset, image_desc.m_rgb_slice_byte_length,
				image_desc.m_alpha_slice_byte_length ? (m_levels[level_index].m_byte_offset.get_uint64() + image_desc.m_alpha_slice_byte_offset) : 0, image_desc.m_alpha_slice_byte_length,
				decode_flags, m_has_alpha,
				m_is_video, output_row_pitch_in_blocks_or_pixels, &pState->m_transcoder_state, output_rows_in_pixels))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_2D: ETC1S transcode_image() failed, this is either a bug or the file is corrupted/invalid\n");
				return false;
			}
		}
		else if (m_format == basist::basis_tex_format::cASTC_HDR_6x6_INTERMEDIATE)
		{
			if (!m_astc_6x6_intermediate_image_descs.size())
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_2D: must call start_transcoding() first\n");
				return false;
			}

			const uint32_t num_blocks6_x = (level_width + 5) / 6;
			const uint32_t num_blocks6_y = (level_height + 5) / 6;

			const uint32_t image_index =
				(level_index * basisu::maximum<uint32_t>(m_header.m_layer_count, 1) * m_header.m_face_count) +
				layer_index * m_header.m_face_count +
				face_index;

			// Sanity check
			if (image_index >= m_astc_6x6_intermediate_image_descs.size())
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_2D: Invalid image_index\n");
				assert(0);
				return false;
			}

			const ktx2_astc_hdr_6x6_intermediate_image_desc& image_desc = m_astc_6x6_intermediate_image_descs[image_index];
						
			if (!m_astc_hdr_6x6_intermediate_transcoder.transcode_image(fmt,
				pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels,
				m_pData, m_data_size, num_blocks6_x, num_blocks6_y, level_width, level_height, level_index,
				m_levels[level_index].m_byte_offset.get_uint64() + image_desc.m_rgb_slice_byte_offset, image_desc.m_rgb_slice_byte_length,
				decode_flags, m_has_alpha, m_is_video, output_row_pitch_in_blocks_or_pixels, nullptr, output_rows_in_pixels, channel0, channel1))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_2D: ASTC 6x6 HDR transcode_image() failed, this is either a bug or the file is corrupted/invalid\n");
				return false;
			}
		}
		else if (m_format == basist::basis_tex_format::cASTC_HDR_6x6)
		{
			const uint32_t num_blocks6_x = (level_width + 5) / 6;
			const uint32_t num_blocks6_y = (level_height + 5) / 6;

			// Compute length and offset to uncompressed 2D UASTC texture data, given the face/layer indices.
			assert(uncomp_level_data_size == m_levels[level_index].m_uncompressed_byte_length.get_uint64());
			const uint32_t total_2D_image_size = num_blocks6_x * num_blocks6_y * sizeof(astc_helpers::astc_block);

			const uint32_t uncomp_ofs = (layer_index * m_header.m_face_count + face_index) * total_2D_image_size;

			// Sanity checks
			if (uncomp_ofs >= uncomp_level_data_size)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_2D: uncomp_ofs >= total_2D_image_size\n");
				return false;
			}

			if ((uncomp_level_data_size - uncomp_ofs) < total_2D_image_size)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_2D: (uncomp_level_data_size - uncomp_ofs) < total_2D_image_size\n");
				return false;
			}

			if (!m_astc_hdr_6x6_transcoder.transcode_image(fmt,
				pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels,
				(const uint8_t*)pUncomp_level_data + uncomp_ofs, (uint32_t)total_2D_image_size, num_blocks6_x, num_blocks6_y, level_width, level_height, level_index,
				0, (uint32_t)total_2D_image_size,
				decode_flags, m_has_alpha, m_is_video, output_row_pitch_in_blocks_or_pixels, nullptr, output_rows_in_pixels, channel0, channel1))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_2D: ASTC 6x6 HDR transcode_image() failed, this is either a bug or the file is corrupted/invalid\n");
				return false;
			}
		}
		else if ((m_format == basist::basis_tex_format::cUASTC4x4) ||
			     (m_format == basist::basis_tex_format::cUASTC_HDR_4x4))
		{
			// Compute length and offset to uncompressed 2D UASTC texture data, given the face/layer indices.
			assert(uncomp_level_data_size == m_levels[level_index].m_uncompressed_byte_length.get_uint64());
			const uint32_t total_2D_image_size = num_blocks4_x * num_blocks4_y * KTX2_UASTC_BLOCK_SIZE;
						
			const uint32_t uncomp_ofs = (layer_index * m_header.m_face_count + face_index) * total_2D_image_size;

			// Sanity checks
			if (uncomp_ofs >= uncomp_level_data_size)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_2D: uncomp_ofs >= total_2D_image_size\n");
				return false;
			}

			if ((uncomp_level_data_size - uncomp_ofs) < total_2D_image_size)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_2D: (uncomp_level_data_size - uncomp_ofs) < total_2D_image_size\n");
				return false;
			}

			if (m_format == basist::basis_tex_format::cUASTC_HDR_4x4)
			{
				if (!m_uastc_hdr_transcoder.transcode_image(fmt,
					pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels,
					(const uint8_t*)pUncomp_level_data + uncomp_ofs, (uint32_t)total_2D_image_size, num_blocks4_x, num_blocks4_y, level_width, level_height, level_index,
					0, (uint32_t)total_2D_image_size,
					decode_flags, m_has_alpha, m_is_video, output_row_pitch_in_blocks_or_pixels, nullptr, output_rows_in_pixels, channel0, channel1))
				{
					BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_2D: UASTC HDR transcode_image() failed, this is either a bug or the file is corrupted/invalid\n");
					return false;
				}
			}
			else
			{
				if (!m_uastc_transcoder.transcode_image(fmt,
					pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels,
					(const uint8_t*)pUncomp_level_data + uncomp_ofs, (uint32_t)total_2D_image_size, num_blocks4_x, num_blocks4_y, level_width, level_height, level_index,
					0, (uint32_t)total_2D_image_size,
					decode_flags, m_has_alpha, m_is_video, output_row_pitch_in_blocks_or_pixels, nullptr, output_rows_in_pixels, channel0, channel1))
				{
					BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_2D: UASTC transcode_image() failed, this is either a bug or the file is corrupted/invalid\n");
					return false;
				}
			}
		}
		else
		{
			// Shouldn't get here.
			BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_2D: Internal error\n");
			assert(0);
			return false;
		}

		return true;
	}
		
	bool ktx2_transcoder::decompress_level_data(uint32_t level_index, basisu::uint8_vec& uncomp_data)
	{
		const uint8_t* pComp_data = m_levels[level_index].m_byte_offset.get_uint64() + m_pData;
		const uint64_t comp_size = m_levels[level_index].m_byte_length.get_uint64();
		
		const uint64_t uncomp_size = m_levels[level_index].m_uncompressed_byte_length.get_uint64();

		if (((size_t)comp_size) != comp_size)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_level_data: Compressed data too large\n");
			return false;
		}
		if (((size_t)uncomp_size) != uncomp_size)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_level_data: Uncompressed data too large\n");
			return false;
		}

		if (!uncomp_data.try_resize((size_t)uncomp_size))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_level_data: Out of memory\n");
			return false;
		}
		
		if (m_header.m_supercompression_scheme == KTX2_SS_ZSTANDARD)
		{
#if BASISD_SUPPORT_KTX2_ZSTD
			size_t actualUncompSize = ZSTD_decompress(uncomp_data.data(), (size_t)uncomp_size, pComp_data, (size_t)comp_size);
			if (ZSTD_isError(actualUncompSize))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_level_data: Zstd decompression failed, file is invalid or corrupted\n");
				return false;
			}
			if (actualUncompSize != uncomp_size)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_level_data: Zstd decompression returned too few bytes, file is invalid or corrupted\n");
				return false;
			}
#else
			BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_level_data: File uses Zstd supercompression, but Zstd support was not enabled at compile time (BASISD_SUPPORT_KTX2_ZSTD is 0)\n");
			return false;
#endif
		}

		return true;
	}

	bool ktx2_transcoder::read_astc_6x6_hdr_intermediate_global_data()
	{
		const uint32_t image_count = basisu::maximum<uint32_t>(m_header.m_layer_count, 1) * m_header.m_face_count * m_header.m_level_count;
		assert(image_count);

		const uint8_t* pSrc = m_pData + m_header.m_sgd_byte_offset.get_uint64();

		if (m_header.m_sgd_byte_length.get_uint64() != image_count * sizeof(ktx2_astc_hdr_6x6_intermediate_image_desc))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_astc_6x6_hdr_intermediate_global_data: Invalid global data length\n");
			return false;
		}

		m_astc_6x6_intermediate_image_descs.resize(image_count);
		
		memcpy((void *)m_astc_6x6_intermediate_image_descs.data(), pSrc, sizeof(ktx2_astc_hdr_6x6_intermediate_image_desc) * image_count);

		// Sanity check the image descs
		for (uint32_t i = 0; i < image_count; i++)
		{
			// transcode_image() will validate the slice offsets/lengths before transcoding.

			if (!m_astc_6x6_intermediate_image_descs[i].m_rgb_slice_byte_length)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_astc_6x6_hdr_intermediate_global_data: image descs sanity check failed (1)\n");
				return false;
			}
		}

		return true;
	}
		
	bool ktx2_transcoder::decompress_etc1s_global_data()
	{
		// Note: we don't actually support 3D textures in here yet
		//uint32_t layer_pixel_depth = basisu::maximum<uint32_t>(m_header.m_pixel_depth, 1);
		//for (uint32_t i = 1; i < m_header.m_level_count; i++)
		//	layer_pixel_depth += basisu::maximum<uint32_t>(m_header.m_pixel_depth >> i, 1);

		const uint32_t image_count = basisu::maximum<uint32_t>(m_header.m_layer_count, 1) * m_header.m_face_count * m_header.m_level_count;
		assert(image_count);

		const uint8_t* pSrc = m_pData + m_header.m_sgd_byte_offset.get_uint64();

		memcpy((void *)&m_etc1s_header, pSrc, sizeof(ktx2_etc1s_global_data_header));
		pSrc += sizeof(ktx2_etc1s_global_data_header);

		if ((!m_etc1s_header.m_endpoints_byte_length) || (!m_etc1s_header.m_selectors_byte_length) || (!m_etc1s_header.m_tables_byte_length))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_etc1s_global_data: Invalid ETC1S global data\n");
			return false;
		}

		if ((!m_etc1s_header.m_endpoint_count) || (!m_etc1s_header.m_selector_count))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_etc1s_global_data: endpoint and/or selector count is 0, file is invalid or corrupted\n");
			return false;
		}

		// Sanity check the ETC1S header.
		if ((sizeof(ktx2_etc1s_global_data_header) +
			sizeof(ktx2_etc1s_image_desc) * image_count +
			m_etc1s_header.m_endpoints_byte_length +
			m_etc1s_header.m_selectors_byte_length +
			m_etc1s_header.m_tables_byte_length +
			m_etc1s_header.m_extended_byte_length) > m_header.m_sgd_byte_length.get_uint64())
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_etc1s_global_data: SGD byte length is too small, file is invalid or corrupted\n");
			return false;
		}
				
		if (!m_etc1s_image_descs.try_resize(image_count))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_etc1s_global_data: Out of memory\n");
			return false;
		}
		
		memcpy((void *)m_etc1s_image_descs.data(), pSrc, sizeof(ktx2_etc1s_image_desc) * image_count);
		pSrc += sizeof(ktx2_etc1s_image_desc) * image_count;

		// Sanity check the ETC1S image descs
		for (uint32_t i = 0; i < image_count; i++)
		{
			// m_etc1s_transcoder.transcode_image() will validate the slice offsets/lengths before transcoding.

			if (!m_etc1s_image_descs[i].m_rgb_slice_byte_length)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_etc1s_global_data: ETC1S image descs sanity check failed (1)\n");
				return false;
			}

			if (m_has_alpha)
			{
				if (!m_etc1s_image_descs[i].m_alpha_slice_byte_length)
				{
					BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_etc1s_global_data: ETC1S image descs sanity check failed (2)\n");
					return false;
				}
			}
		}

		const uint8_t* pEndpoint_data = pSrc;
		const uint8_t* pSelector_data = pSrc + m_etc1s_header.m_endpoints_byte_length;
		const uint8_t* pTables_data = pSrc + m_etc1s_header.m_endpoints_byte_length + m_etc1s_header.m_selectors_byte_length;

		if (!m_etc1s_transcoder.decode_tables(pTables_data, m_etc1s_header.m_tables_byte_length))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_etc1s_global_data: decode_tables() failed, file is invalid or corrupted\n");
			return false;
		}
				
		if (!m_etc1s_transcoder.decode_palettes(
			m_etc1s_header.m_endpoint_count,	pEndpoint_data, m_etc1s_header.m_endpoints_byte_length,
			m_etc1s_header.m_selector_count,	pSelector_data, m_etc1s_header.m_selectors_byte_length))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_etc1s_global_data: decode_palettes() failed, file is likely corrupted\n");
			return false;
		}
				
		return true;
	}

	bool ktx2_transcoder::read_key_values()
	{
		if (!m_header.m_kvd_byte_length)
		{
			if (m_header.m_kvd_byte_offset)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Invalid KVD byte offset (it should be zero when the length is zero)\n");
				return false;
			}

			return true;
		}

		if (m_header.m_kvd_byte_offset < sizeof(ktx2_header))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Invalid KVD byte offset\n");
			return false;
		}

		if ((m_header.m_kvd_byte_offset + m_header.m_kvd_byte_length) > m_data_size)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Invalid KVD byte offset and/or length\n");
			return false;
		}

		const uint8_t* pSrc = m_pData + m_header.m_kvd_byte_offset;
		uint32_t src_left = m_header.m_kvd_byte_length;

		if (!m_key_values.try_reserve(8))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Out of memory\n");
			return false;
		}

		while (src_left > sizeof(uint32_t))
		{
			uint32_t l = basisu::read_le_dword(pSrc);
			
			pSrc += sizeof(uint32_t);
			src_left -= sizeof(uint32_t);

			if (l < 2)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Failed reading key value fields (0)\n");
				return false;
			}

			if (src_left < l)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Failed reading key value fields (1)\n");
				return false;
			}

			if (!m_key_values.try_resize(m_key_values.size() + 1))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Out of memory\n");
				return false;
			}
			
			basisu::uint8_vec& key_data = m_key_values.back().m_key;
			basisu::uint8_vec& value_data = m_key_values.back().m_value;

			do
			{
				if (!l)
				{
					BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Failed reading key value fields (2)\n");
					return false;
				}

				if (!key_data.try_push_back(*pSrc++))
				{
					BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Out of memory\n");
					return false;
				}

				src_left--;
				l--;

			} while (key_data.back());

			// Ensure key and value are definitely 0 terminated
			if (!key_data.try_push_back('\0'))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Out of memory\n");
				return false;
			}
						
			if (!value_data.try_resize(l))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Out of memory\n");
				return false;
			}

			if (l)
			{
				memcpy(value_data.data(), pSrc, l);
				pSrc += l;
				src_left -= l;
			}

			// Ensure key and value are definitely 0 terminated
			if (!value_data.try_push_back('\0'))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Out of memory\n");
				return false;
			}

			uint32_t ofs = (uint32_t)(pSrc - m_pData) & 3;
			uint32_t alignment_bytes = (4 - ofs) & 3;

			if (src_left < alignment_bytes)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Failed reading key value fields (3)\n");
				return false;
			}

			pSrc += alignment_bytes;
			src_left -= alignment_bytes;
		}

		return true;
	}
		
#endif // BASISD_SUPPORT_KTX2

	bool basisu_transcoder_supports_ktx2()
	{
#if BASISD_SUPPORT_KTX2
		return true;
#else
		return false;
#endif
	}

	bool basisu_transcoder_supports_ktx2_zstd()
	{
#if BASISD_SUPPORT_KTX2_ZSTD
		return true;
#else
		return false;
#endif
	}

	//-------------------------------

#if BASISD_SUPPORT_UASTC_HDR
	// This float->half conversion matches how "F32TO16" works on Intel GPU's.
	basist::half_float float_to_half(float val)
	{
		union { float f; int32_t i; uint32_t u; } fi = { val };
		const int flt_m = fi.i & 0x7FFFFF, flt_e = (fi.i >> 23) & 0xFF, flt_s = (fi.i >> 31) & 0x1;
		int s = flt_s, e = 0, m = 0;

		// inf/NaN
		if (flt_e == 0xff)
		{
			e = 31;
			if (flt_m != 0) // NaN
				m = 1;
		}
		// not zero or denormal
		else if (flt_e != 0)
		{
			int new_exp = flt_e - 127;
			if (new_exp > 15)
				e = 31;
			else if (new_exp < -14)
				m = lrintf((1 << 24) * fabsf(fi.f));
			else
			{
				e = new_exp + 15;
				m = lrintf(flt_m * (1.0f / ((float)(1 << 13))));
			}
		}

		assert((0 <= m) && (m <= 1024));
		if (m == 1024)
		{
			e++;
			m = 0;
		}

		assert((s >= 0) && (s <= 1));
		assert((e >= 0) && (e <= 31));
		assert((m >= 0) && (m <= 1023));

		basist::half_float result = (basist::half_float)((s << 15) | (e << 10) | m);
		return result;
	}
		
	//------------------------------------------------------------------------------------------------
	// HDR support
	// 
	// Originally from bc6h_enc.cpp
	// BC6H decoder fuzzed vs. DirectXTex's for unsigned/signed

	const uint8_t g_bc6h_mode_sig_bits[NUM_BC6H_MODES][4] = // base bits, r, g, b
	{
		// 2 subsets
		{ 10, 5, 5, 5, },	// 0, mode 1 in MS/D3D docs
		{ 7, 6, 6, 6, },	// 1
		{ 11, 5, 4, 4, },	// 2
		{ 11, 4, 5, 4, },	// 3
		{ 11, 4, 4, 5, },	// 4
		{ 9, 5, 5, 5, },	// 5
		{ 8, 6, 5, 5, },	// 6
		{ 8, 5, 6, 5, },	// 7
		{ 8, 5, 5, 6, },	// 8
		{ 6, 6, 6, 6, },	// 9, endpoints not delta encoded, mode 10 in MS/D3D docs
		// 1 subset
		{ 10, 10, 10, 10, }, // 10, endpoints not delta encoded, mode 11 in MS/D3D docs
		{ 11, 9, 9, 9, },	// 11
		{ 12, 8, 8, 8, },	// 12
		{ 16, 4, 4, 4, }	// 13, also useful for solid blocks
	};

	const int8_t g_bc6h_mode_lookup[32] = { 0, 1, 2, 10, 0, 1, 3, 11, 0, 1, 4, 12, 0, 1, 5, 13, 0, 1, 6, -1, 0, 1, 7, -1, 0, 1, 8, -1, 0, 1, 9, -1 };

	const bc6h_bit_layout g_bc6h_bit_layouts[NUM_BC6H_MODES][MAX_BC6H_LAYOUT_INDEX] =
	{
		// comp_index, subset*2+lh_index, last_bit, first_bit
		//------------------------        mode 0: 2 subsets, Weight bits: 46 bits, Endpoint bits: 75 bits (10.555, 10.555, 10.555), delta            
		{ { 1, 2, 4, -1 }, { 2, 2, 4, -1 }, { 2, 3, 4, -1 }, { 0, 0, 9, 0 }, { 1, 0, 9, 0 }, { 2, 0, 9, 0 }, { 0, 1, 4, 0 },
		{ 1, 3, 4, -1 }, { 1, 2, 3, 0 }, { 1, 1, 4, 0 }, { 2, 3, 0, -1 }, { 1, 3, 3, 0 }, { 2, 1, 4, 0 }, { 2, 3, 1, -1 },
		{ 2, 2, 3, 0 }, { 0, 2, 4, 0 }, { 2, 3, 2, -1 }, { 0, 3, 4, 0 }, { 2, 3, 3, -1 }, { 3, -1, 4, 0 }, {-1, 0, 0, 0} },
		//------------------------        mode 1: 2 subsets, Weight bits: 46 bits, Endpoint bits: 75 bits (7.666, 7.666, 7.666), delta
		{ { 1, 2, 5, -1 },{ 1, 3, 4, -1 },{ 1, 3, 5, -1 },{ 0, 0, 6, 0 },{ 2, 3, 0, -1 },{ 2, 3, 1, -1 },{ 2, 2, 4, -1 },
		{ 1, 0, 6, 0 },{ 2, 2, 5, -1 },{ 2, 3, 2, -1 },{ 1, 2, 4, -1 },{ 2, 0, 6, 0 },{ 2, 3, 3, -1 },{ 2, 3, 5, -1 },
		{ 2, 3, 4, -1 },{ 0, 1, 5, 0 },{ 1, 2, 3, 0 },{ 1, 1, 5, 0 },{ 1, 3, 3, 0 },{ 2, 1, 5, 0 },{ 2, 2, 3, 0 },{ 0, 2, 5, 0 },
		{ 0, 3, 5, 0 },{ 3, -1, 4, 0 }, {-1, 0, 0, 0} },
		//------------------------        mode 2: 2 subsets, Weight bits: 46 bits, Endpoint bits: 72 bits (11.555, 11.444, 11.444), delta
		{ { 0, 0, 9, 0 },{ 1, 0, 9, 0 },{ 2, 0, 9, 0 },{ 0, 1, 4, 0 },{ 0, 0, 10, -1 },{ 1, 2, 3, 0 },{ 1, 1, 3, 0 },{ 1, 0, 10, -1 },
		{ 2, 3, 0, -1 },{ 1, 3, 3, 0 },{ 2, 1, 3, 0 },{ 2, 0, 10, -1 },{ 2, 3, 1, -1 },{ 2, 2, 3, 0 },{ 0, 2, 4, 0 },{ 2, 3, 2, -1 },
		{ 0, 3, 4, 0 },{ 2, 3, 3, -1 },{ 3, -1, 4, 0 }, {-1, 0, 0, 0} },
		//------------------------        mode 3: 2 subsets, Weight bits: 46 bits, Endpoint bits: 72 bits (11.444, 11.555, 11.444), delta
		{ { 0, 0, 9, 0 },{ 1, 0, 9, 0 },{ 2, 0, 9, 0 },{ 0, 1, 3, 0 },{ 0, 0, 10, -1 },{ 1, 3, 4, -1 },{ 1, 2, 3, 0 },{ 1, 1, 4, 0 },
		{ 1, 0, 10, -1 },{ 1, 3, 3, 0 },{ 2, 1, 3, 0 },{ 2, 0, 10, -1 },{ 2, 3, 1, -1 },{ 2, 2, 3, 0 },{ 0, 2, 3, 0 },{ 2, 3, 0, -1 },
		{ 2, 3, 2, -1 },{ 0, 3, 3, 0 },{ 1, 2, 4, -1 },{ 2, 3, 3, -1 },{ 3, -1, 4, 0 }, {-1, 0, 0, 0} },
		//------------------------        mode 4: 2 subsets, Weight bits: 46 bits, Endpoint bits: 72 bits (11.444, 11.444, 11.555), delta
		{ { 0, 0, 9, 0 },{ 1, 0, 9, 0 },{ 2, 0, 9, 0 },{ 0, 1, 3, 0 },{ 0, 0, 10, -1 },{ 2, 2, 4, -1 },{ 1, 2, 3, 0 },{ 1, 1, 3, 0 },
		{ 1, 0, 10, -1 },{ 2, 3, 0, -1 },{ 1, 3, 3, 0 },{ 2, 1, 4, 0 },{ 2, 0, 10, -1 },{ 2, 2, 3, 0 },{ 0, 2, 3, 0 },{ 2, 3, 1, -1 },
		{ 2, 3, 2, -1 },{ 0, 3, 3, 0 },{ 2, 3, 4, -1 },{ 2, 3, 3, -1 },{ 3, -1, 4, 0 }, {-1, 0, 0, 0} },
		//------------------------        mode 5: 2 subsets, Weight bits: 46 bits, Endpoint bits: 72 bits (9.555, 9.555, 9.555), delta
		{ { 0, 0, 8, 0 },{ 2, 2, 4, -1 },{ 1, 0, 8, 0 },{ 1, 2, 4, -1 },{ 2, 0, 8, 0 },{ 2, 3, 4, -1 },{ 0, 1, 4, 0 },{ 1, 3, 4, -1 },
		{ 1, 2, 3, 0 },{ 1, 1, 4, 0 },{ 2, 3, 0, -1 },{ 1, 3, 3, 0 },{ 2, 1, 4, 0 },{ 2, 3, 1, -1 },{ 2, 2, 3, 0 },{ 0, 2, 4, 0 },
		{ 2, 3, 2, -1 },{ 0, 3, 4, 0 },{ 2, 3, 3, -1 },{ 3, -1, 4, 0 }, {-1, 0, 0, 0} },
		//------------------------        mode 6: 2 subsets, Weight bits: 46 bits, Endpoint bits: 72 bits (8.666, 8.555, 8.555), delta
		{ { 0, 0, 7, 0 },{ 1, 3, 4, -1 },{ 2, 2, 4, -1 },{ 1, 0, 7, 0 },{ 2, 3, 2, -1 },{ 1, 2, 4, -1 },{ 2, 0, 7, 0 },{ 2, 3, 3, -1 },
		{ 2, 3, 4, -1 },{ 0, 1, 5, 0 },{ 1, 2, 3, 0 },{ 1, 1, 4, 0 },{ 2, 3, 0, -1 },{ 1, 3, 3, 0 },{ 2, 1, 4, 0 },{ 2, 3, 1, -1 },
		{ 2, 2, 3, 0 },{ 0, 2, 5, 0 },{ 0, 3, 5, 0 },{ 3, -1, 4, 0 }, {-1, 0, 0, 0} },
		//------------------------        mode 7: 2 subsets, Weight bits: 46 bits, Endpoints bits: 72 bits (8.555, 8.666, 8.555), delta
		{ { 0, 0, 7, 0 },{ 2, 3, 0, -1 },{ 2, 2, 4, -1 },{ 1, 0, 7, 0 },{ 1, 2, 5, -1 },{ 1, 2, 4, -1 },{ 2, 0, 7, 0 },{ 1, 3, 5, -1 },
		{ 2, 3, 4, -1 },{ 0, 1, 4, 0 },{ 1, 3, 4, -1 },{ 1, 2, 3, 0 },{ 1, 1, 5, 0 },{ 1, 3, 3, 0 },{ 2, 1, 4, 0 },{ 2, 3, 1, -1 },
		{ 2, 2, 3, 0 },{ 0, 2, 4, 0 },{ 2, 3, 2, -1 },{ 0, 3, 4, 0 },{ 2, 3, 3, -1 },{ 3, -1, 4, 0 }, {-1, 0, 0, 0} },
		//------------------------        mode 8: 2 subsets, Weight bits: 46 bits, Endpoint bits: 72 bits (8.555, 8.555, 8.666), delta
		{ { 0, 0, 7, 0 },{ 2, 3, 1, -1 },{ 2, 2, 4, -1 },{ 1, 0, 7, 0 },{ 2, 2, 5, -1 },{ 1, 2, 4, -1 },{ 2, 0, 7, 0 },{ 2, 3, 5, -1 },
		{ 2, 3, 4, -1 },{ 0, 1, 4, 0 },{ 1, 3, 4, -1 },{ 1, 2, 3, 0 },{ 1, 1, 4, 0 },{ 2, 3, 0, -1 },{ 1, 3, 3, 0 },{ 2, 1, 5, 0 },
		{ 2, 2, 3, 0 },{ 0, 2, 4, 0 },{ 2, 3, 2, -1 },{ 0, 3, 4, 0 },{ 2, 3, 3, -1 },{ 3, -1, 4, 0 }, {-1, 0, 0, 0} },
		//------------------------        mode 9: 2 subsets, Weight bits: 46 bits, Endpoint bits: 72 bits (6.6.6.6, 6.6.6.6, 6.6.6.6), NO delta
		{ { 0, 0, 5, 0 },{ 1, 3, 4, -1 },{ 2, 3, 0, -1 },{ 2, 3, 1, -1 },{ 2, 2, 4, -1 },{ 1, 0, 5, 0 },{ 1, 2, 5, -1 },{ 2, 2, 5, -1 },
		{ 2, 3, 2, -1 },{ 1, 2, 4, -1 },{ 2, 0, 5, 0 },{ 1, 3, 5, -1 },{ 2, 3, 3, -1 },{ 2, 3, 5, -1 },{ 2, 3, 4, -1 },{ 0, 1, 5, 0 },
		{ 1, 2, 3, 0 },{ 1, 1, 5, 0 },{ 1, 3, 3, 0 },{ 2, 1, 5, 0 },{ 2, 2, 3, 0 },{ 0, 2, 5, 0 },{ 0, 3, 5, 0 },{ 3, -1, 4, 0 }, {-1, 0, 0, 0} },
		//------------------------        mode 10: 1 subset, Weight bits: 63 bits, Endpoint bits: 60 bits (10.10, 10.10, 10.10), NO delta
		{ { 0, 0, 9, 0 },{ 1, 0, 9, 0 },{ 2, 0, 9, 0 },{ 0, 1, 9, 0 },{ 1, 1, 9, 0 },{ 2, 1, 9, 0 }, {-1, 0, 0, 0} },
		//------------------------        mode 11: 1 subset, Weight bits: 63 bits, Endpoint bits: 60 bits (11.9, 11.9, 11.9), delta
		{ { 0, 0, 9, 0 },{ 1, 0, 9, 0 },{ 2, 0, 9, 0 },{ 0, 1, 8, 0 },{ 0, 0, 10, -1 },{ 1, 1, 8, 0 },{ 1, 0, 10, -1 },{ 2, 1, 8, 0 },{ 2, 0, 10, -1 }, {-1, 0, 0, 0} },
		//------------------------        mode 12: 1 subset, Weight bits: 63 bits, Endpoint bits: 60 bits (12.8, 12.8, 12.8), delta
		{ { 0, 0, 9, 0 },{ 1, 0, 9, 0 },{ 2, 0, 9, 0 },{ 0, 1, 7, 0 },{ 0, 0, 10, 11 },{ 1, 1, 7, 0 },{ 1, 0, 10, 11 },{ 2, 1, 7, 0 },{ 2, 0, 10, 11 }, {-1, 0, 0, 0} },
		//------------------------        mode 13: 1 subset, Weight bits: 63 bits, Endpoint bits: 60 bits (16.4, 16.4, 16.4), delta
		{ { 0, 0, 9, 0 },{ 1, 0, 9, 0 },{ 2, 0, 9, 0 },{ 0, 1, 3, 0 },{ 0, 0, 10, 15 },{ 1, 1, 3, 0 },{ 1, 0, 10, 15 },{ 2, 1, 3, 0 },{ 2, 0, 10, 15 }, {-1, 0, 0, 0} }
	};

	// The same as the first 32 2-subset patterns in BC7. 
	// Bit 7 is a flag indicating that the weight uses 1 less bit than usual.
	const uint8_t g_bc6h_2subset_patterns[TOTAL_BC6H_PARTITION_PATTERNS][4][4] = // [pat][y][x]
	{
		{ {0x80, 0, 1, 1}, { 0, 0, 1, 1 }, { 0, 0, 1, 1 }, { 0, 0, 1, 0x81 }}, { {0x80, 0, 0, 1}, {0, 0, 0, 1}, {0, 0, 0, 1}, {0, 0, 0, 0x81} },
		{ {0x80, 1, 1, 1}, {0, 1, 1, 1}, {0, 1, 1, 1}, {0, 1, 1, 0x81} }, { {0x80, 0, 0, 1}, {0, 0, 1, 1}, {0, 0, 1, 1}, {0, 1, 1, 0x81} },
		{ {0x80, 0, 0, 0}, {0, 0, 0, 1}, {0, 0, 0, 1}, {0, 0, 1, 0x81} }, { {0x80, 0, 1, 1}, {0, 1, 1, 1}, {0, 1, 1, 1}, {1, 1, 1, 0x81} },
		{ {0x80, 0, 0, 1}, {0, 0, 1, 1}, {0, 1, 1, 1}, {1, 1, 1, 0x81} }, { {0x80, 0, 0, 0}, {0, 0, 0, 1}, {0, 0, 1, 1}, {0, 1, 1, 0x81} },
		{ {0x80, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 1}, {0, 0, 1, 0x81} }, { {0x80, 0, 1, 1}, {0, 1, 1, 1}, {1, 1, 1, 1}, {1, 1, 1, 0x81} },
		{ {0x80, 0, 0, 0}, {0, 0, 0, 1}, {0, 1, 1, 1}, {1, 1, 1, 0x81} }, { {0x80, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 1}, {0, 1, 1, 0x81} },
		{ {0x80, 0, 0, 1}, {0, 1, 1, 1}, {1, 1, 1, 1}, {1, 1, 1, 0x81} }, { {0x80, 0, 0, 0}, {0, 0, 0, 0}, {1, 1, 1, 1}, {1, 1, 1, 0x81} },
		{ {0x80, 0, 0, 0}, {1, 1, 1, 1}, {1, 1, 1, 1}, {1, 1, 1, 0x81} }, { {0x80, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {1, 1, 1, 0x81} },
		{ {0x80, 0, 0, 0}, {1, 0, 0, 0}, {1, 1, 1, 0}, {1, 1, 1, 0x81} }, { {0x80, 1, 0x81, 1}, {0, 0, 0, 1}, {0, 0, 0, 0}, {0, 0, 0, 0} },
		{ {0x80, 0, 0, 0}, {0, 0, 0, 0}, {0x81, 0, 0, 0}, {1, 1, 1, 0} }, { {0x80, 1, 0x81, 1}, {0, 0, 1, 1}, {0, 0, 0, 1}, {0, 0, 0, 0} },
		{ {0x80, 0, 0x81, 1}, {0, 0, 0, 1}, {0, 0, 0, 0}, {0, 0, 0, 0} }, { {0x80, 0, 0, 0}, {1, 0, 0, 0}, {0x81, 1, 0, 0}, {1, 1, 1, 0} },
		{ {0x80, 0, 0, 0}, {0, 0, 0, 0}, {0x81, 0, 0, 0}, {1, 1, 0, 0} }, { {0x80, 1, 1, 1}, {0, 0, 1, 1}, {  0, 0, 1, 1}, {0, 0, 0, 0x81} },
		{ {0x80, 0, 0x81, 1}, {0, 0, 0, 1}, {0, 0, 0, 1}, {0, 0, 0, 0} }, { {0x80, 0, 0, 0}, {1, 0, 0, 0}, {0x81, 0, 0, 0}, {1, 1, 0, 0} },
		{ {0x80, 1, 0x81, 0}, {0, 1, 1, 0}, {0, 1, 1, 0}, {0, 1, 1, 0} }, { {0x80, 0, 0x81, 1}, {0, 1, 1, 0}, {0, 1, 1, 0}, {1, 1, 0, 0} },
		{ {0x80, 0, 0, 1}, {0, 1, 1, 1}, {0x81, 1, 1, 0}, {1, 0, 0, 0} }, { {0x80, 0, 0, 0}, {1, 1, 1, 1}, {0x81, 1, 1, 1}, {0, 0, 0, 0} },
		{ {0x80, 1, 0x81, 1}, {0, 0, 0, 1}, {1, 0, 0, 0}, {1, 1, 1, 0} }, { {0x80, 0, 0x81, 1}, {1, 0, 0, 1}, {1, 0, 0, 1}, {1, 1, 0, 0} }
	};

	const uint8_t g_bc6h_weight3[8] = { 0, 9, 18, 27, 37, 46, 55, 64 };
	const uint8_t g_bc6h_weight4[16] = { 0, 4, 9, 13, 17, 21, 26, 30, 34, 38, 43, 47, 51, 55, 60, 64 };
	
	static inline void write_bits(uint64_t val, uint32_t num_bits, uint32_t& bit_pos, uint64_t& l, uint64_t& h)
	{
		assert((num_bits) && (num_bits < 64) && (bit_pos < 128));
		assert(val < (1ULL << num_bits));

		if (bit_pos < 64)
		{
			l |= (val << bit_pos);

			if ((bit_pos + num_bits) > 64)
				h |= (val >> (64 - bit_pos));
		}
		else
		{
			h |= (val << (bit_pos - 64));
		}

		bit_pos += num_bits;
		assert(bit_pos <= 128);
	}

	static inline void write_rev_bits(uint64_t val, uint32_t num_bits, uint32_t& bit_pos, uint64_t& l, uint64_t& h)
	{
		assert((num_bits) && (num_bits < 64) && (bit_pos < 128));
		assert(val < (1ULL << num_bits));

		for (uint32_t i = 0; i < num_bits; i++)
			write_bits((val >> (num_bits - 1u - i)) & 1, 1, bit_pos, l, h);
	}

	void pack_bc6h_block(bc6h_block& dst_blk, bc6h_logical_block& log_blk)
	{
		const uint8_t s_mode_bits[NUM_BC6H_MODES] = { 0b00, 0b01, 0b00010, 0b00110, 0b01010, 0b01110, 0b10010, 0b10110, 0b11010, 0b11110, 0b00011, 0b00111, 0b01011, 0b01111 };

		const uint32_t mode = log_blk.m_mode;
		assert(mode < NUM_BC6H_MODES);

		uint64_t l = s_mode_bits[mode], h = 0;
		uint32_t bit_pos = (mode >= 2) ? 5 : 2;

		const uint32_t num_subsets = (mode >= BC6H_FIRST_1SUBSET_MODE_INDEX) ? 1 : 2;

		assert(((num_subsets == 2) && (log_blk.m_partition_pattern < TOTAL_BC6H_PARTITION_PATTERNS)) ||
			((num_subsets == 1) && (!log_blk.m_partition_pattern)));

		// Sanity checks
		for (uint32_t c = 0; c < 3; c++)
		{
			assert(log_blk.m_endpoints[c][0] < (1u << g_bc6h_mode_sig_bits[mode][0]));	   // 1st subset l, base bits
			assert(log_blk.m_endpoints[c][1] < (1u << g_bc6h_mode_sig_bits[mode][c + 1])); // 1st subset h, these are deltas except for modes 9,10
			assert(log_blk.m_endpoints[c][2] < (1u << g_bc6h_mode_sig_bits[mode][c + 1])); // 2nd subset l
			assert(log_blk.m_endpoints[c][3] < (1u << g_bc6h_mode_sig_bits[mode][c + 1])); // 2nd subset h
		}

		const bc6h_bit_layout* pLayout = &g_bc6h_bit_layouts[mode][0];

		while (pLayout->m_comp != -1)
		{
			uint32_t v = (pLayout->m_comp == 3) ? log_blk.m_partition_pattern : log_blk.m_endpoints[pLayout->m_comp][pLayout->m_index];

			if (pLayout->m_first_bit == -1)
			{
				write_bits((v >> pLayout->m_last_bit) & 1, 1, bit_pos, l, h);
			}
			else
			{
				const uint32_t total_bits = basisu::iabs(pLayout->m_last_bit - pLayout->m_first_bit) + 1;

				v >>= basisu::minimum(pLayout->m_first_bit, pLayout->m_last_bit);
				v &= ((1 << total_bits) - 1);

				if (pLayout->m_first_bit > pLayout->m_last_bit)
					write_rev_bits(v, total_bits, bit_pos, l, h);
				else
					write_bits(v, total_bits, bit_pos, l, h);
			}

			pLayout++;
		}

		const uint32_t num_mode_sel_bits = (num_subsets == 1) ? 4 : 3;
		const uint8_t* pPat = &g_bc6h_2subset_patterns[log_blk.m_partition_pattern][0][0];

		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t sel = log_blk.m_weights[i];

			uint32_t num_bits = num_mode_sel_bits;
			if (num_subsets == 2)
			{
				const uint32_t subset_index = pPat[i];
				num_bits -= (subset_index >> 7);
			}
			else if (!i)
			{
				num_bits--;
			}

			assert(sel < (1u << num_bits));

			write_bits(sel, num_bits, bit_pos, l, h);
		}

		assert(bit_pos == 128);

		basisu::write_le_dword(&dst_blk.m_bytes[0], (uint32_t)l);
		basisu::write_le_dword(&dst_blk.m_bytes[4], (uint32_t)(l >> 32u));
		basisu::write_le_dword(&dst_blk.m_bytes[8], (uint32_t)h);
		basisu::write_le_dword(&dst_blk.m_bytes[12], (uint32_t)(h >> 32u));
	}

#if 0
	static inline uint32_t bc6h_blog_dequantize_to_blog16(uint32_t comp, uint32_t bits_per_comp)
	{
		int unq;

		if (bits_per_comp >= 15)
			unq = comp;
		else if (comp == 0)
			unq = 0;
		else if (comp == ((1u << bits_per_comp) - 1u))
			unq = 0xFFFFu;
		else
			unq = ((comp << 16u) + 0x8000u) >> bits_per_comp;

		return unq;
	}
#endif
		
	// 6,7,8,9,10,11,12
	const uint32_t BC6H_BLOG_TAB_MIN = 6;
	const uint32_t BC6H_BLOG_TAB_MAX = 12;
	//const uint32_t BC6H_BLOG_TAB_NUM = BC6H_BLOG_TAB_MAX - BC6H_BLOG_TAB_MIN + 1;
	
	// Handles 16, or 6-12 bits. Others assert.
	static inline uint32_t half_to_blog_tab(half_float h, uint32_t num_bits)
	{
		assert(h <= MAX_BC6H_HALF_FLOAT_AS_UINT);
		assert((num_bits == 16) || ((num_bits >= BC6H_BLOG_TAB_MIN) && (num_bits <= BC6H_BLOG_TAB_MAX)));

		return bc6h_half_to_blog(h, num_bits);
#if 0
		BASISU_NOTE_UNUSED(BC6H_BLOG_TAB_MIN);
		BASISU_NOTE_UNUSED(BC6H_BLOG_TAB_MAX);

		if (num_bits == 16)
		{
			return bc6h_half_to_blog(h, 16);
		}
		else
		{
			assert((num_bits >= BC6H_BLOG_TAB_MIN) && (num_bits <= BC6H_BLOG_TAB_MAX));
			
			// Note: This used to be done using a table lookup, but it required ~224KB of tables. This isn't quite as accurate, but the error is very slight (+-1 half values as ints).
			return bc6h_half_to_blog(h, num_bits);
		}
#endif
	}

	bool g_bc6h_enc_initialized;

	void bc6h_enc_init()
	{
		if (g_bc6h_enc_initialized)
			return;

		g_bc6h_enc_initialized = true;
	}

	// mode 10, 4-bit weights
	void bc6h_enc_block_mode10(bc6h_block* pPacked_block, const half_float pEndpoints[3][2], const uint8_t* pWeights)
	{
		assert(g_bc6h_enc_initialized);

		for (uint32_t i = 0; i < 16; i++)
		{
			assert(pWeights[i] <= 15);
		}

		bc6h_logical_block log_blk;
		log_blk.clear();

		// Convert half endpoints to blog10 (mode 10 doesn't use delta encoding)
		for (uint32_t c = 0; c < 3; c++)
		{
			log_blk.m_endpoints[c][0] = half_to_blog_tab(pEndpoints[c][0], 10);
			log_blk.m_endpoints[c][1] = half_to_blog_tab(pEndpoints[c][1], 10);
		}

		memcpy(log_blk.m_weights, pWeights, 16);

		if (log_blk.m_weights[0] & 8)
		{
			for (uint32_t i = 0; i < 16; i++)
				log_blk.m_weights[i] = 15 - log_blk.m_weights[i];

			for (uint32_t c = 0; c < 3; c++)
			{
				std::swap(log_blk.m_endpoints[c][0], log_blk.m_endpoints[c][1]);
			}
		}

		log_blk.m_mode = BC6H_FIRST_1SUBSET_MODE_INDEX;
		pack_bc6h_block(*pPacked_block, log_blk);
	}

	// Tries modes 11-13 (delta endpoint) encoding, falling back to mode 10 only when necessary, 4-bit weights
	void bc6h_enc_block_1subset_4bit_weights(bc6h_block* pPacked_block, const half_float pEndpoints[3][2], const uint8_t* pWeights)
	{
		assert(g_bc6h_enc_initialized);

		for (uint32_t i = 0; i < 16; i++)
		{
			assert(pWeights[i] <= 15);
		}

		bc6h_logical_block log_blk;
		log_blk.clear();

		for (uint32_t mode = BC6H_LAST_MODE_INDEX; mode > BC6H_FIRST_1SUBSET_MODE_INDEX; mode--)
		{
			const uint32_t num_base_bits = g_bc6h_mode_sig_bits[mode][0], num_delta_bits = g_bc6h_mode_sig_bits[mode][1];
			const int base_bitmask = (1 << num_base_bits) - 1;
			const int delta_bitmask = (1 << num_delta_bits) - 1;
			BASISU_NOTE_UNUSED(base_bitmask);

			assert(num_delta_bits < num_base_bits);
			assert((num_delta_bits == g_bc6h_mode_sig_bits[mode][2]) && (num_delta_bits == g_bc6h_mode_sig_bits[mode][3]));

			uint32_t blog_endpoints[3][2];

			// Convert half endpoints to blog 16, 12, or 11
			for (uint32_t c = 0; c < 3; c++)
			{
				blog_endpoints[c][0] = half_to_blog_tab(pEndpoints[c][0], num_base_bits);
				assert((int)blog_endpoints[c][0] <= base_bitmask);

				blog_endpoints[c][1] = half_to_blog_tab(pEndpoints[c][1], num_base_bits);
				assert((int)blog_endpoints[c][1] <= base_bitmask);
			}

			// Copy weights
			memcpy(log_blk.m_weights, pWeights, 16);

			// Ensure first weight MSB is 0
			if (log_blk.m_weights[0] & 8)
			{
				// Invert weights
				for (uint32_t i = 0; i < 16; i++)
					log_blk.m_weights[i] = 15 - log_blk.m_weights[i];

				// Swap blog quantized endpoints
				for (uint32_t c = 0; c < 3; c++)
				{
					std::swap(blog_endpoints[c][0], blog_endpoints[c][1]);
				}
			}

			const int max_delta = (1 << (num_delta_bits - 1)) - 1;
			const int min_delta = -(max_delta + 1);
			assert((max_delta - min_delta) == delta_bitmask);

			bool failed_flag = false;
			for (uint32_t c = 0; c < 3; c++)
			{
				log_blk.m_endpoints[c][0] = blog_endpoints[c][0];

				int delta = (int)blog_endpoints[c][1] - (int)blog_endpoints[c][0];
				if ((delta < min_delta) || (delta > max_delta))
				{
					failed_flag = true;
					break;
				}

				log_blk.m_endpoints[c][1] = delta & delta_bitmask;
			}

			if (failed_flag)
				continue;

			log_blk.m_mode = mode;
			pack_bc6h_block(*pPacked_block, log_blk);
						
			return;
		}

		// Worst case fall back to mode 10, which can handle any endpoints
		bc6h_enc_block_mode10(pPacked_block, pEndpoints, pWeights);
	}

	// Mode 9 (direct endpoint encoding), 3-bit weights, but only 1 subset
	void bc6h_enc_block_1subset_mode9_3bit_weights(bc6h_block* pPacked_block, const half_float pEndpoints[3][2], const uint8_t* pWeights)
	{
		assert(g_bc6h_enc_initialized);

		for (uint32_t i = 0; i < 16; i++)
		{
			assert(pWeights[i] <= 7);
		}

		bc6h_logical_block log_blk;
		log_blk.clear();

		// Convert half endpoints to blog6 (mode 9 doesn't use delta encoding)
		for (uint32_t c = 0; c < 3; c++)
		{
			log_blk.m_endpoints[c][0] = half_to_blog_tab(pEndpoints[c][0], 6);
			log_blk.m_endpoints[c][2] = log_blk.m_endpoints[c][0];

			log_blk.m_endpoints[c][1] = half_to_blog_tab(pEndpoints[c][1], 6);
			log_blk.m_endpoints[c][3] = log_blk.m_endpoints[c][1];
		}

		memcpy(log_blk.m_weights, pWeights, 16);

		const uint32_t pat_index = 0;
		const uint8_t* pPat = &g_bc6h_2subset_patterns[pat_index][0][0];

		if (log_blk.m_weights[0] & 4)
		{
			for (uint32_t c = 0; c < 3; c++)
				std::swap(log_blk.m_endpoints[c][0], log_blk.m_endpoints[c][1]);

			for (uint32_t i = 0; i < 16; i++)
				if ((pPat[i] & 0x7F) == 0)
					log_blk.m_weights[i] = 7 - log_blk.m_weights[i];
		}

		if (log_blk.m_weights[15] & 4)
		{
			for (uint32_t c = 0; c < 3; c++)
				std::swap(log_blk.m_endpoints[c][2], log_blk.m_endpoints[c][3]);

			for (uint32_t i = 0; i < 16; i++)
				if ((pPat[i] & 0x7F) == 1)
					log_blk.m_weights[i] = 7 - log_blk.m_weights[i];
		}

		log_blk.m_mode = 9;
		log_blk.m_partition_pattern = pat_index;
		pack_bc6h_block(*pPacked_block, log_blk);
	}

	// Tries modes 0-8, falls back to mode 9
	void bc6h_enc_block_1subset_3bit_weights(bc6h_block* pPacked_block, const half_float pEndpoints[3][2], const uint8_t* pWeights)
	{
		assert(g_bc6h_enc_initialized);

		for (uint32_t i = 0; i < 16; i++)
		{
			assert(pWeights[i] <= 7);
		}

		bc6h_logical_block log_blk;
		log_blk.clear();

		for (uint32_t mode_iter = 0; mode_iter <= 8; mode_iter++)
		{
			static const int s_mode_order[9] = { 2, 3, 4, 0,  5, 6, 7, 8,  1 }; // ordered from largest base bits to least
			const uint32_t mode = s_mode_order[mode_iter];

			const uint32_t num_base_bits = g_bc6h_mode_sig_bits[mode][0];
			const int base_bitmask = (1 << num_base_bits) - 1;
			BASISU_NOTE_UNUSED(base_bitmask);

			const uint32_t num_delta_bits[3] = { g_bc6h_mode_sig_bits[mode][1], g_bc6h_mode_sig_bits[mode][2], g_bc6h_mode_sig_bits[mode][3] };
			const int delta_bitmasks[3] = { (1 << num_delta_bits[0]) - 1, (1 << num_delta_bits[1]) - 1, (1 << num_delta_bits[2]) - 1 };

			uint32_t blog_endpoints[3][4];

			// Convert half endpoints to blog 7-11
			for (uint32_t c = 0; c < 3; c++)
			{
				blog_endpoints[c][0] = half_to_blog_tab(pEndpoints[c][0], num_base_bits);
				blog_endpoints[c][2] = blog_endpoints[c][0];
				assert((int)blog_endpoints[c][0] <= base_bitmask);

				blog_endpoints[c][1] = half_to_blog_tab(pEndpoints[c][1], num_base_bits);
				blog_endpoints[c][3] = blog_endpoints[c][1];
				assert((int)blog_endpoints[c][1] <= base_bitmask);
			}

			const uint32_t pat_index = 0;
			const uint8_t* pPat = &g_bc6h_2subset_patterns[pat_index][0][0];

			memcpy(log_blk.m_weights, pWeights, 16);

			if (log_blk.m_weights[0] & 4)
			{
				// Swap part 0's endpoints/weights
				for (uint32_t c = 0; c < 3; c++)
					std::swap(blog_endpoints[c][0], blog_endpoints[c][1]);

				for (uint32_t i = 0; i < 16; i++)
					if ((pPat[i] & 0x7F) == 0)
						log_blk.m_weights[i] = 7 - log_blk.m_weights[i];
			}

			if (log_blk.m_weights[15] & 4)
			{
				// Swap part 1's endpoints/weights
				for (uint32_t c = 0; c < 3; c++)
					std::swap(blog_endpoints[c][2], blog_endpoints[c][3]);

				for (uint32_t i = 0; i < 16; i++)
					if ((pPat[i] & 0x7F) == 1)
						log_blk.m_weights[i] = 7 - log_blk.m_weights[i];
			}

			bool failed_flag = false;

			for (uint32_t c = 0; c < 3; c++)
			{
				const int max_delta = (1 << (num_delta_bits[c] - 1)) - 1;

				const int min_delta = -(max_delta + 1);
				assert((max_delta - min_delta) == delta_bitmasks[c]);

				log_blk.m_endpoints[c][0] = blog_endpoints[c][0];

				int delta0 = (int)blog_endpoints[c][1] - (int)blog_endpoints[c][0];
				int delta1 = (int)blog_endpoints[c][2] - (int)blog_endpoints[c][0];
				int delta2 = (int)blog_endpoints[c][3] - (int)blog_endpoints[c][0];

				if ((delta0 < min_delta) || (delta0 > max_delta) ||
					(delta1 < min_delta) || (delta1 > max_delta) ||
					(delta2 < min_delta) || (delta2 > max_delta))
				{
					failed_flag = true;
					break;
				}

				log_blk.m_endpoints[c][1] = delta0 & delta_bitmasks[c];
				log_blk.m_endpoints[c][2] = delta1 & delta_bitmasks[c];
				log_blk.m_endpoints[c][3] = delta2 & delta_bitmasks[c];
			}

			if (failed_flag)
				continue;

			log_blk.m_mode = mode;
			log_blk.m_partition_pattern = pat_index;
			pack_bc6h_block(*pPacked_block, log_blk);

			return;

		} // mode_iter

		bc6h_enc_block_1subset_mode9_3bit_weights(pPacked_block, pEndpoints, pWeights);
	}

	// pEndpoints[subset][comp][lh_index]
	void bc6h_enc_block_2subset_mode9_3bit_weights(bc6h_block* pPacked_block, uint32_t common_part_index, const half_float pEndpoints[2][3][2], const uint8_t* pWeights)
	{
		assert(g_bc6h_enc_initialized);
		assert(common_part_index < basist::TOTAL_ASTC_BC7_COMMON_PARTITIONS2);

		for (uint32_t i = 0; i < 16; i++)
		{
			assert(pWeights[i] <= 7);
		}

		bc6h_logical_block log_blk;
		log_blk.clear();

		// Convert half endpoints to blog6 (mode 9 doesn't use delta encoding)
		for (uint32_t s = 0; s < 2; s++)
		{
			for (uint32_t c = 0; c < 3; c++)
			{
				log_blk.m_endpoints[c][0 + s * 2] = half_to_blog_tab(pEndpoints[s][c][0], 6);
				log_blk.m_endpoints[c][1 + s * 2] = half_to_blog_tab(pEndpoints[s][c][1], 6);
			}
		}

		memcpy(log_blk.m_weights, pWeights, 16);

		//const uint32_t astc_pattern = basist::g_astc_bc7_common_partitions2[common_part_index].m_astc;
		const uint32_t bc7_pattern = basist::g_astc_bc7_common_partitions2[common_part_index].m_bc7;

		const bool invert_flag = basist::g_astc_bc7_common_partitions2[common_part_index].m_invert;
		if (invert_flag)
		{
			for (uint32_t c = 0; c < 3; c++)
			{
				std::swap(log_blk.m_endpoints[c][0], log_blk.m_endpoints[c][2]);
				std::swap(log_blk.m_endpoints[c][1], log_blk.m_endpoints[c][3]);
			}
		}

		const uint32_t pat_index = bc7_pattern;
		assert(pat_index < 32);
		const uint8_t* pPat = &g_bc6h_2subset_patterns[pat_index][0][0];

		bool swap_flags[2] = { false, false };
		for (uint32_t i = 0; i < 16; i++)
		{
			if ((pPat[i] & 0x80) == 0)
				continue;

			if (log_blk.m_weights[i] & 4)
			{
				const uint32_t p = pPat[i] & 1;
				swap_flags[p] = true;
			}
		}

		if (swap_flags[0])
		{
			for (uint32_t c = 0; c < 3; c++)
				std::swap(log_blk.m_endpoints[c][0], log_blk.m_endpoints[c][1]);

			for (uint32_t i = 0; i < 16; i++)
				if ((pPat[i] & 0x7F) == 0)
					log_blk.m_weights[i] = 7 - log_blk.m_weights[i];
		}

		if (swap_flags[1])
		{
			for (uint32_t c = 0; c < 3; c++)
				std::swap(log_blk.m_endpoints[c][2], log_blk.m_endpoints[c][3]);

			for (uint32_t i = 0; i < 16; i++)
				if ((pPat[i] & 0x7F) == 1)
					log_blk.m_weights[i] = 7 - log_blk.m_weights[i];
		}

		log_blk.m_mode = 9;
		log_blk.m_partition_pattern = pat_index;
		pack_bc6h_block(*pPacked_block, log_blk);
	}

	void bc6h_enc_block_2subset_3bit_weights(bc6h_block* pPacked_block, uint32_t common_part_index, const half_float pEndpoints[2][3][2], const uint8_t* pWeights)
	{
		assert(g_bc6h_enc_initialized);

		for (uint32_t i = 0; i < 16; i++)
		{
			assert(pWeights[i] <= 7);
		}

		bc6h_logical_block log_blk;
		log_blk.clear();

		for (uint32_t mode_iter = 0; mode_iter <= 8; mode_iter++)
		{
			static const int s_mode_order[9] = { 2, 3, 4, 0,  5, 6, 7, 8,  1 }; // ordered from largest base bits to least
			const uint32_t mode = s_mode_order[mode_iter];

			const uint32_t num_base_bits = g_bc6h_mode_sig_bits[mode][0];
			const int base_bitmask = (1 << num_base_bits) - 1;
			BASISU_NOTE_UNUSED(base_bitmask);

			const uint32_t num_delta_bits[3] = { g_bc6h_mode_sig_bits[mode][1], g_bc6h_mode_sig_bits[mode][2], g_bc6h_mode_sig_bits[mode][3] };
			const int delta_bitmasks[3] = { (1 << num_delta_bits[0]) - 1, (1 << num_delta_bits[1]) - 1, (1 << num_delta_bits[2]) - 1 };

			uint32_t blog_endpoints[3][4];

			// Convert half endpoints to blog 7-11
			for (uint32_t s = 0; s < 2; s++)
			{
				for (uint32_t c = 0; c < 3; c++)
				{
					blog_endpoints[c][0 + s * 2] = half_to_blog_tab(pEndpoints[s][c][0], num_base_bits);
					blog_endpoints[c][1 + s * 2] = half_to_blog_tab(pEndpoints[s][c][1], num_base_bits);
				}
			}

			memcpy(log_blk.m_weights, pWeights, 16);

			//const uint32_t astc_pattern = basist::g_astc_bc7_common_partitions2[common_part_index].m_astc;
			const uint32_t bc7_pattern = basist::g_astc_bc7_common_partitions2[common_part_index].m_bc7;

			const bool invert_flag = basist::g_astc_bc7_common_partitions2[common_part_index].m_invert;
			if (invert_flag)
			{
				for (uint32_t c = 0; c < 3; c++)
				{
					std::swap(blog_endpoints[c][0], blog_endpoints[c][2]);
					std::swap(blog_endpoints[c][1], blog_endpoints[c][3]);
				}
			}

			const uint32_t pat_index = bc7_pattern;
			assert(pat_index < 32);
			const uint8_t* pPat = &g_bc6h_2subset_patterns[pat_index][0][0];

			bool swap_flags[2] = { false, false };
			for (uint32_t i = 0; i < 16; i++)
			{
				if ((pPat[i] & 0x80) == 0)
					continue;

				if (log_blk.m_weights[i] & 4)
				{
					const uint32_t p = pPat[i] & 1;
					swap_flags[p] = true;
				}
			}

			if (swap_flags[0])
			{
				for (uint32_t c = 0; c < 3; c++)
					std::swap(blog_endpoints[c][0], blog_endpoints[c][1]);

				for (uint32_t i = 0; i < 16; i++)
					if ((pPat[i] & 0x7F) == 0)
						log_blk.m_weights[i] = 7 - log_blk.m_weights[i];
			}

			if (swap_flags[1])
			{
				for (uint32_t c = 0; c < 3; c++)
					std::swap(blog_endpoints[c][2], blog_endpoints[c][3]);

				for (uint32_t i = 0; i < 16; i++)
					if ((pPat[i] & 0x7F) == 1)
						log_blk.m_weights[i] = 7 - log_blk.m_weights[i];
			}

			// Try packing the endpoints
			bool failed_flag = false;

			for (uint32_t c = 0; c < 3; c++)
			{
				const int max_delta = (1 << (num_delta_bits[c] - 1)) - 1;

				const int min_delta = -(max_delta + 1);
				assert((max_delta - min_delta) == delta_bitmasks[c]);

				log_blk.m_endpoints[c][0] = blog_endpoints[c][0];

				int delta0 = (int)blog_endpoints[c][1] - (int)blog_endpoints[c][0];
				int delta1 = (int)blog_endpoints[c][2] - (int)blog_endpoints[c][0];
				int delta2 = (int)blog_endpoints[c][3] - (int)blog_endpoints[c][0];

				if ((delta0 < min_delta) || (delta0 > max_delta) ||
					(delta1 < min_delta) || (delta1 > max_delta) ||
					(delta2 < min_delta) || (delta2 > max_delta))
				{
					failed_flag = true;
					break;
				}

				log_blk.m_endpoints[c][1] = delta0 & delta_bitmasks[c];
				log_blk.m_endpoints[c][2] = delta1 & delta_bitmasks[c];
				log_blk.m_endpoints[c][3] = delta2 & delta_bitmasks[c];
			}

			if (failed_flag)
				continue;

			log_blk.m_mode = mode;
			log_blk.m_partition_pattern = pat_index;
			pack_bc6h_block(*pPacked_block, log_blk);

			//half_float blk[16 * 3];
			//unpack_bc6h(pPacked_block, blk, false);

			return;
		}

		bc6h_enc_block_2subset_mode9_3bit_weights(pPacked_block, common_part_index, pEndpoints, pWeights);
	}

	bool bc6h_enc_block_solid_color(bc6h_block* pPacked_block, const half_float pColor[3])
	{
		assert(g_bc6h_enc_initialized);

		if ((pColor[0] | pColor[1] | pColor[2]) & 0x8000)
			return false;

		// ASTC block unpacker won't allow Inf/NaN's to come through.
		//if (is_half_inf_or_nan(pColor[0]) || is_half_inf_or_nan(pColor[1]) || is_half_inf_or_nan(pColor[2]))
		//	return false;

		uint8_t weights[16];
		memset(weights, 0, sizeof(weights));

		half_float endpoints[3][2];
		endpoints[0][0] = pColor[0];
		endpoints[0][1] = pColor[0];
				
		endpoints[1][0] = pColor[1];
		endpoints[1][1] = pColor[1];

		endpoints[2][0] = pColor[2];
		endpoints[2][1] = pColor[2];
				
		bc6h_enc_block_1subset_4bit_weights(pPacked_block, endpoints, weights);

		return true;
	}

	//--------------------------------------------------------------------------------------------------------------------------
	// basisu_astc_hdr_core.cpp

	static bool g_astc_hdr_core_initialized;
	static int8_t g_astc_partition_id_to_common_bc7_pat_index[1024];

	//--------------------------------------------------------------------------------------------------------------------------

	void astc_hdr_core_init()
	{
		if (g_astc_hdr_core_initialized)
			return;

		memset(g_astc_partition_id_to_common_bc7_pat_index, 0xFF, sizeof(g_astc_partition_id_to_common_bc7_pat_index));

		for (uint32_t part_index = 0; part_index < basist::TOTAL_ASTC_BC6H_COMMON_PARTITIONS2; ++part_index)
		{
			const uint32_t astc_pattern = basist::g_astc_bc7_common_partitions2[part_index].m_astc;
			//const uint32_t bc7_pattern = basist::g_astc_bc7_common_partitions2[part_index].m_bc7;

			assert(astc_pattern < 1024);
			g_astc_partition_id_to_common_bc7_pat_index[astc_pattern] = (int8_t)part_index;
		}

		g_astc_hdr_core_initialized = true;
	}

	//--------------------------------------------------------------------------------------------------------------------------

	static inline int astc_hdr_sign_extend(int src, int num_src_bits)
	{
		assert(basisu::in_range(num_src_bits, 2, 31));

		const bool negative = (src & (1 << (num_src_bits - 1))) != 0;
		if (negative)
			return src | ~((1 << num_src_bits) - 1);
		else
			return src & ((1 << num_src_bits) - 1);
	}

	static inline void astc_hdr_pack_bit(
		int& dst, int dst_bit,
		int src_val, int src_bit = 0)
	{
		assert(dst_bit >= 0 && dst_bit <= 31);
		int bit = basisu::get_bit(src_val, src_bit);
		dst |= (bit << dst_bit);
	}

	//--------------------------------------------------------------------------------------------------------------------------

	void decode_mode7_to_qlog12_ise20(
		const uint8_t* pEndpoints,
		int e[2][3],
		int* pScale)
	{
		assert(g_astc_hdr_core_initialized);

		for (uint32_t i = 0; i < NUM_MODE7_ENDPOINTS; i++)
		{
			assert(pEndpoints[i] <= 255);
		}

		const int v0 = pEndpoints[0], v1 = pEndpoints[1], v2 = pEndpoints[2], v3 = pEndpoints[3];

		// Extract mode bits and unpack to major component and mode.
		const int modeval = ((v0 & 0xC0) >> 6) | ((v1 & 0x80) >> 5) | ((v2 & 0x80) >> 4);

		int majcomp, mode;
		if ((modeval & 0xC) != 0xC)
		{
			majcomp = modeval >> 2;
			mode = modeval & 3;
		}
		else if (modeval != 0xF)
		{
			majcomp = modeval & 3;
			mode = 4;
		}
		else
		{
			majcomp = 0;
			mode = 5;
		}

		// Extract low-order bits of r, g, b, and s.
		int red = v0 & 0x3f;
		int green = v1 & 0x1f;
		int blue = v2 & 0x1f;
		int scale = v3 & 0x1f;

		// Extract high-order bits, which may be assigned depending on mode
		int x0 = (v1 >> 6) & 1;
		int x1 = (v1 >> 5) & 1;
		int x2 = (v2 >> 6) & 1;
		int x3 = (v2 >> 5) & 1;
		int x4 = (v3 >> 7) & 1;
		int x5 = (v3 >> 6) & 1;
		int x6 = (v3 >> 5) & 1;

		// Now move the high-order xs into the right place.
		const int ohm = 1 << mode;
		if (ohm & 0x30) green |= x0 << 6;
		if (ohm & 0x3A) green |= x1 << 5;
		if (ohm & 0x30) blue |= x2 << 6;
		if (ohm & 0x3A) blue |= x3 << 5;
		if (ohm & 0x3D) scale |= x6 << 5;
		if (ohm & 0x2D) scale |= x5 << 6;
		if (ohm & 0x04) scale |= x4 << 7;
		if (ohm & 0x3B) red |= x4 << 6;
		if (ohm & 0x04) red |= x3 << 6;
		if (ohm & 0x10) red |= x5 << 7;
		if (ohm & 0x0F) red |= x2 << 7;
		if (ohm & 0x05) red |= x1 << 8;
		if (ohm & 0x0A) red |= x0 << 8;
		if (ohm & 0x05) red |= x0 << 9;
		if (ohm & 0x02) red |= x6 << 9;
		if (ohm & 0x01) red |= x3 << 10;
		if (ohm & 0x02) red |= x5 << 10;

		// Shift the bits to the top of the 12-bit result.
		static const int s_shamts[6] = { 1,1,2,3,4,5 };

		const int shamt = s_shamts[mode];
		red <<= shamt;
		green <<= shamt;
		blue <<= shamt;
		scale <<= shamt;

		// Minor components are stored as differences
		if (mode != 5)
		{
			green = red - green;
			blue = red - blue;
		}

		// Swizzle major component into place
		if (majcomp == 1)
			std::swap(red, green);

		if (majcomp == 2)
			std::swap(red, blue);

		// Clamp output values, set alpha to 1.0
		e[1][0] = basisu::clamp(red, 0, 0xFFF);
		e[1][1] = basisu::clamp(green, 0, 0xFFF);
		e[1][2] = basisu::clamp(blue, 0, 0xFFF);

		e[0][0] = basisu::clamp(red - scale, 0, 0xFFF);
		e[0][1] = basisu::clamp(green - scale, 0, 0xFFF);
		e[0][2] = basisu::clamp(blue - scale, 0, 0xFFF);

		if (pScale)
			*pScale = scale;
	}

	//--------------------------------------------------------------------------------------------------------------------------

	bool decode_mode7_to_qlog12(
		const uint8_t* pEndpoints,
		int e[2][3],
		int* pScale,
		uint32_t ise_endpoint_range)
	{
		assert(g_astc_hdr_core_initialized);

		if (ise_endpoint_range == astc_helpers::BISE_256_LEVELS)
		{
			decode_mode7_to_qlog12_ise20(pEndpoints, e, pScale);
		}
		else
		{
			uint8_t dequantized_endpoints[NUM_MODE7_ENDPOINTS];

			for (uint32_t i = 0; i < NUM_MODE7_ENDPOINTS; i++)
				dequantized_endpoints[i] = astc_helpers::g_dequant_tables.get_endpoint_tab(ise_endpoint_range).m_ISE_to_val[pEndpoints[i]];

			decode_mode7_to_qlog12_ise20(dequantized_endpoints, e, pScale);
		}

		for (uint32_t i = 0; i < 2; i++)
		{
			if (e[i][0] > (int)MAX_QLOG12)
				return false;

			if (e[i][1] > (int)MAX_QLOG12)
				return false;

			if (e[i][2] > (int)MAX_QLOG12)
				return false;
		}

		return true;
	}

	//--------------------------------------------------------------------------------------------------------------------------

	void decode_mode11_to_qlog12_ise20(
		const uint8_t* pEndpoints,
		int e[2][3])
	{
#ifdef _DEBUG
		for (uint32_t i = 0; i < NUM_MODE11_ENDPOINTS; i++)
		{
			assert(pEndpoints[i] <= 255);
		}
#endif

		const uint32_t maj_comp = basisu::get_bit(pEndpoints[4], 7) | (basisu::get_bit(pEndpoints[5], 7) << 1);

		if (maj_comp == 3)
		{
			// Direct, qlog8 and qlog7
			e[0][0] = pEndpoints[0] << 4;
			e[1][0] = pEndpoints[1] << 4;

			e[0][1] = pEndpoints[2] << 4;
			e[1][1] = pEndpoints[3] << 4;

			e[0][2] = (pEndpoints[4] & 127) << 5;
			e[1][2] = (pEndpoints[5] & 127) << 5;
		}
		else
		{
			int v0 = pEndpoints[0];
			int v1 = pEndpoints[1];
			int v2 = pEndpoints[2];
			int v3 = pEndpoints[3];
			int v4 = pEndpoints[4];
			int v5 = pEndpoints[5];

			int mode = 0;
			astc_hdr_pack_bit(mode, 0, v1, 7);
			astc_hdr_pack_bit(mode, 1, v2, 7);
			astc_hdr_pack_bit(mode, 2, v3, 7);

			int va = v0;
			astc_hdr_pack_bit(va, 8, v1, 6);

			int vb0 = v2 & 63;
			int vb1 = v3 & 63;
			int vc = v1 & 63;

			int vd0 = v4 & 0x7F; // this takes more bits than is sometimes needed
			int vd1 = v5 & 0x7F; // this takes more bits than is sometimes needed
			static const int8_t dbitstab[8] = { 7,6,7,6,5,6,5,6 };
			vd0 = astc_hdr_sign_extend(vd0, dbitstab[mode]);
			vd1 = astc_hdr_sign_extend(vd1, dbitstab[mode]);

			int x0 = basisu::get_bit(v2, 6);
			int x1 = basisu::get_bit(v3, 6);
			int x2 = basisu::get_bit(v4, 6);
			int x3 = basisu::get_bit(v5, 6);
			int x4 = basisu::get_bit(v4, 5);
			int x5 = basisu::get_bit(v5, 5);

			const uint32_t ohm = 1U << mode;
			if (ohm & 0xA4) va |= (x0 << 9);
			if (ohm & 0x08) va |= (x2 << 9);
			if (ohm & 0x50) va |= (x4 << 9);
			if (ohm & 0x50) va |= (x5 << 10);
			if (ohm & 0xA0) va |= (x1 << 10);
			if (ohm & 0xC0) va |= (x2 << 11);
			if (ohm & 0x04) vc |= (x1 << 6);
			if (ohm & 0xE8) vc |= (x3 << 6);
			if (ohm & 0x20) vc |= (x2 << 7);
			if (ohm & 0x5B) vb0 |= (x0 << 6);
			if (ohm & 0x5B) vb1 |= (x1 << 6);
			if (ohm & 0x12) vb0 |= (x2 << 7);
			if (ohm & 0x12) vb1 |= (x3 << 7);

			const int shamt = (mode >> 1) ^ 3;
			
			va  = (uint32_t)va  << shamt;
			vb0 = (uint32_t)vb0 << shamt;
			vb1 = (uint32_t)vb1 << shamt;
			vc  = (uint32_t)vc  << shamt;
			vd0 = (uint32_t)vd0 << shamt;
			vd1 = (uint32_t)vd1 << shamt;

			// qlog12
			e[1][0] = basisu::clamp<int>(va, 0, 0xFFF);
			e[1][1] = basisu::clamp<int>(va - vb0, 0, 0xFFF);
			e[1][2] = basisu::clamp<int>(va - vb1, 0, 0xFFF);

			e[0][0] = basisu::clamp<int>(va - vc, 0, 0xFFF);
			e[0][1] = basisu::clamp<int>(va - vb0 - vc - vd0, 0, 0xFFF);
			e[0][2] = basisu::clamp<int>(va - vb1 - vc - vd1, 0, 0xFFF);

			if (maj_comp)
			{
				std::swap(e[0][0], e[0][maj_comp]);
				std::swap(e[1][0], e[1][maj_comp]);
			}
		}
	}

	//--------------------------------------------------------------------------------------------------------------------------

	bool decode_mode11_to_qlog12(
		const uint8_t* pEndpoints,
		int e[2][3],
		uint32_t ise_endpoint_range)
	{
		assert(g_astc_hdr_core_initialized);
		assert((ise_endpoint_range >= astc_helpers::FIRST_VALID_ENDPOINT_ISE_RANGE) && (ise_endpoint_range <= astc_helpers::LAST_VALID_ENDPOINT_ISE_RANGE));

		if (ise_endpoint_range == astc_helpers::BISE_256_LEVELS)
		{
			decode_mode11_to_qlog12_ise20(pEndpoints, e);
		}
		else
		{
			uint8_t dequantized_endpoints[NUM_MODE11_ENDPOINTS];

			for (uint32_t i = 0; i < NUM_MODE11_ENDPOINTS; i++)
				dequantized_endpoints[i] = astc_helpers::g_dequant_tables.get_endpoint_tab(ise_endpoint_range).m_ISE_to_val[pEndpoints[i]];

			decode_mode11_to_qlog12_ise20(dequantized_endpoints, e);
		}

		for (uint32_t i = 0; i < 2; i++)
		{
			if (e[i][0] > (int)MAX_QLOG12)
				return false;

			if (e[i][1] > (int)MAX_QLOG12)
				return false;

			if (e[i][2] > (int)MAX_QLOG12)
				return false;
		}

		return true;
	}

	//--------------------------------------------------------------------------------------------------------------------------

	bool transcode_bc6h_1subset(half_float h_e[3][2], const astc_helpers::log_astc_block& best_blk, bc6h_block& transcoded_bc6h_blk)
	{
		assert(g_astc_hdr_core_initialized);
		assert((best_blk.m_weight_ise_range >= 1) && (best_blk.m_weight_ise_range <= 8));
		
		if (best_blk.m_weight_ise_range == 5)
		{
			// Use 3-bit BC6H weights which are a perfect match for 3-bit ASTC weights, but encode 1-subset as 2 equal subsets
			bc6h_enc_block_1subset_3bit_weights(&transcoded_bc6h_blk, h_e, best_blk.m_weights);
		}
		else
		{
			uint8_t bc6h_weights[16];

			if (best_blk.m_weight_ise_range == 1)
			{
				// weight ISE 1: 3 levels
				static const uint8_t s_astc1_to_bc6h_3[3] = { 0, 8, 15 };

				for (uint32_t i = 0; i < 16; i++)
					bc6h_weights[i] = s_astc1_to_bc6h_3[best_blk.m_weights[i]];
			}
			else if (best_blk.m_weight_ise_range == 2)
			{
				// weight ISE 2: 4 levels
				static const uint8_t s_astc2_to_bc6h_4[4] = { 0, 5, 10, 15 };

				for (uint32_t i = 0; i < 16; i++)
					bc6h_weights[i] = s_astc2_to_bc6h_4[best_blk.m_weights[i]];
			}
			else if (best_blk.m_weight_ise_range == 3)
			{
				// weight ISE 3: 5 levels
				static const uint8_t s_astc3_to_bc6h_4[5] = { 0, 4, 7, 11, 15 };

				for (uint32_t i = 0; i < 16; i++)
					bc6h_weights[i] = s_astc3_to_bc6h_4[best_blk.m_weights[i]];
			}
			else if (best_blk.m_weight_ise_range == 4)
			{
				// weight ISE 4: 6 levels
				static const uint8_t s_astc4_to_bc6h_4[6] = { 0, 15, 3, 12, 6, 9 };

				for (uint32_t i = 0; i < 16; i++)
					bc6h_weights[i] = s_astc4_to_bc6h_4[best_blk.m_weights[i]];
			}
			else if (best_blk.m_weight_ise_range == 6)
			{
				// weight ISE 6: 10 levels
				static const uint8_t s_astc6_to_bc6h_4[10] = { 0, 15, 2, 13, 3, 12, 5, 10, 6, 9 };

				for (uint32_t i = 0; i < 16; i++)
					bc6h_weights[i] = s_astc6_to_bc6h_4[best_blk.m_weights[i]];
			}
			else if (best_blk.m_weight_ise_range == 7)
			{
				// weight ISE 7: 12 levels
				static const uint8_t s_astc7_to_bc6h_4[12] = { 0, 15, 4, 11, 1, 14, 5, 10, 2, 13, 6, 9 };

				for (uint32_t i = 0; i < 16; i++)
					bc6h_weights[i] = s_astc7_to_bc6h_4[best_blk.m_weights[i]];
			}
			else if (best_blk.m_weight_ise_range == 8)
			{
				// 16 levels
				memcpy(bc6h_weights, best_blk.m_weights, 16);
			}
			else
			{
				assert(0);
				return false;
			}

			bc6h_enc_block_1subset_4bit_weights(&transcoded_bc6h_blk, h_e, bc6h_weights);
		}

		return true;
	}

	//--------------------------------------------------------------------------------------------------------------------------

	bool transcode_bc6h_2subsets(uint32_t common_part_index, const astc_helpers::log_astc_block& best_blk, bc6h_block& transcoded_bc6h_blk)
	{
		assert(g_astc_hdr_core_initialized);
		assert(best_blk.m_num_partitions == 2);
		assert(common_part_index < basist::TOTAL_ASTC_BC6H_COMMON_PARTITIONS2);
		
		half_float bc6h_endpoints[2][3][2]; // [subset][comp][lh_index]

		// UASTC HDR checks
		// Both CEM's must be equal in 2-subset UASTC HDR.
		if (best_blk.m_color_endpoint_modes[0] != best_blk.m_color_endpoint_modes[1])
			return false;
		if ((best_blk.m_color_endpoint_modes[0] != 7) && (best_blk.m_color_endpoint_modes[0] != 11))
			return false;
				
		if (best_blk.m_color_endpoint_modes[0] == 7)
		{
			if (!(((best_blk.m_weight_ise_range == 1) && (best_blk.m_endpoint_ise_range == 20)) ||
		 		  ((best_blk.m_weight_ise_range == 2) && (best_blk.m_endpoint_ise_range == 20)) ||
				  ((best_blk.m_weight_ise_range == 3) && (best_blk.m_endpoint_ise_range == 19)) ||
				  ((best_blk.m_weight_ise_range == 4) && (best_blk.m_endpoint_ise_range == 17)) ||
				  ((best_blk.m_weight_ise_range == 5) && (best_blk.m_endpoint_ise_range == 15))))
			{
				return false;
			}
		}
		else
		{
			if (!(((best_blk.m_weight_ise_range == 1) && (best_blk.m_endpoint_ise_range == 14)) ||
				  ((best_blk.m_weight_ise_range == 2) && (best_blk.m_endpoint_ise_range == 12))))
			{
				return false;
			}
		}

		for (uint32_t s = 0; s < 2; s++)
		{
			int e[2][3];
			if (best_blk.m_color_endpoint_modes[0] == 7)
			{
				bool success = decode_mode7_to_qlog12(best_blk.m_endpoints + s * NUM_MODE7_ENDPOINTS, e, nullptr, best_blk.m_endpoint_ise_range);
				if (!success)
					return false;
			}
			else
			{
				bool success = decode_mode11_to_qlog12(best_blk.m_endpoints + s * NUM_MODE11_ENDPOINTS, e, best_blk.m_endpoint_ise_range);
				if (!success)
					return false;
			}

			for (uint32_t c = 0; c < 3; c++)
			{
				bc6h_endpoints[s][c][0] = qlog_to_half(e[0][c], 12);
				if (is_half_inf_or_nan(bc6h_endpoints[s][c][0]))
					return false;

				bc6h_endpoints[s][c][1] = qlog_to_half(e[1][c], 12);
				if (is_half_inf_or_nan(bc6h_endpoints[s][c][1]))
					return false;
			}
		}

		uint8_t bc6h_weights[16];
		if (best_blk.m_weight_ise_range == 1)
		{
			static const uint8_t s_astc1_to_bc6h_3[3] = { 0, 4, 7 };

			for (uint32_t i = 0; i < 16; i++)
				bc6h_weights[i] = s_astc1_to_bc6h_3[best_blk.m_weights[i]];
		}
		else if (best_blk.m_weight_ise_range == 2)
		{
			static const uint8_t s_astc2_to_bc6h_3[4] = { 0, 2, 5, 7 };

			for (uint32_t i = 0; i < 16; i++)
				bc6h_weights[i] = s_astc2_to_bc6h_3[best_blk.m_weights[i]];
		}
		else if (best_blk.m_weight_ise_range == 3)
		{
			static const uint8_t s_astc3_to_bc6h_3[5] = { 0, 2, 4, 5, 7 };

			for (uint32_t i = 0; i < 16; i++)
				bc6h_weights[i] = s_astc3_to_bc6h_3[best_blk.m_weights[i]];
		}
		else if (best_blk.m_weight_ise_range == 4)
		{
			static const uint8_t s_astc4_to_bc6h_3[6] = { 0, 7, 1, 6, 3, 4 };

			for (uint32_t i = 0; i < 16; i++)
				bc6h_weights[i] = s_astc4_to_bc6h_3[best_blk.m_weights[i]];
		}
		else if (best_blk.m_weight_ise_range == 5)
		{
			memcpy(bc6h_weights, best_blk.m_weights, 16);
		}
		else
		{
			assert(0);
			return false;
		}

		bc6h_enc_block_2subset_3bit_weights(&transcoded_bc6h_blk, common_part_index, bc6h_endpoints, bc6h_weights);

		return true;
	}

	//--------------------------------------------------------------------------------------------------------------------------
	// Transcodes an UASTC HDR block to BC6H. Must have been encoded to UASTC HDR, or this fails.
	bool astc_hdr_transcode_to_bc6h(const astc_blk& src_blk, bc6h_block& dst_blk)
	{
		assert(g_astc_hdr_core_initialized);
		if (!g_astc_hdr_core_initialized)
		{
			assert(0);
			return false;
		}

		astc_helpers::log_astc_block log_blk;

		if (!astc_helpers::unpack_block(&src_blk, log_blk, 4, 4))
		{
			// Failed unpacking ASTC data
			return false;
		}

		return astc_hdr_transcode_to_bc6h(log_blk, dst_blk);
	}

	//--------------------------------------------------------------------------------------------------------------------------
	// Transcodes an UASTC HDR block to BC6H. Must have been encoded to UASTC HDR, or this fails.
	bool astc_hdr_transcode_to_bc6h(const astc_helpers::log_astc_block& log_blk, bc6h_block& dst_blk)
	{
		assert(g_astc_hdr_core_initialized);
		if (!g_astc_hdr_core_initialized)
		{
			assert(0);
			return false;
		}
				
		if (log_blk.m_solid_color_flag_ldr)
		{
			// Don't support LDR solid colors.
			return false;
		}

		if (log_blk.m_solid_color_flag_hdr)
		{
			// Solid color HDR block
			return bc6h_enc_block_solid_color(&dst_blk, log_blk.m_solid_color);
		}

		// Only support 4x4 grid sizes
		if ((log_blk.m_grid_width != 4) || (log_blk.m_grid_height != 4))
			return false;
				
		// Don't support dual plane encoding
		if (log_blk.m_dual_plane)
			return false;

		if (log_blk.m_num_partitions == 1)
		{
			// Handle 1 partition (or subset)
			
			// UASTC HDR checks
			if ((log_blk.m_weight_ise_range < 1) || (log_blk.m_weight_ise_range > 8))
				return false;
									
			int e[2][3];
			bool success;

			if (log_blk.m_color_endpoint_modes[0] == 7)
			{
				if (log_blk.m_endpoint_ise_range != 20)
					return false;

				success = decode_mode7_to_qlog12(log_blk.m_endpoints, e, nullptr, log_blk.m_endpoint_ise_range);
			}
			else if (log_blk.m_color_endpoint_modes[0] == 11)
			{
				// UASTC HDR checks
				if (log_blk.m_weight_ise_range <= 7)
				{
					if (log_blk.m_endpoint_ise_range != 20)
						return false;
				}
				else if (log_blk.m_endpoint_ise_range != 19)
				{
					return false;
				}

				success = decode_mode11_to_qlog12(log_blk.m_endpoints, e, log_blk.m_endpoint_ise_range);
			}
			else
			{
				return false;
			}

			if (!success)
				return false;

			// Transform endpoints to half float
			half_float h_e[3][2] =
			{
				{ qlog_to_half(e[0][0], 12), qlog_to_half(e[1][0], 12) },
				{ qlog_to_half(e[0][1], 12), qlog_to_half(e[1][1], 12) },
				{ qlog_to_half(e[0][2], 12), qlog_to_half(e[1][2], 12) }
			};

			// Sanity check for NaN/Inf
			for (uint32_t i = 0; i < 2; i++)
				if (is_half_inf_or_nan(h_e[0][i]) || is_half_inf_or_nan(h_e[1][i]) || is_half_inf_or_nan(h_e[2][i]))
					return false;
			
			// Transcode to bc6h
			if (!transcode_bc6h_1subset(h_e, log_blk, dst_blk))
				return false;
		}
		else if (log_blk.m_num_partitions == 2)
		{
			// Handle 2 partition (or subset)
			int common_bc7_pat_index = g_astc_partition_id_to_common_bc7_pat_index[log_blk.m_partition_id];
			if (common_bc7_pat_index < 0)
				return false;

			assert(common_bc7_pat_index < (int)basist::TOTAL_ASTC_BC6H_COMMON_PARTITIONS2);
						
			if (!transcode_bc6h_2subsets(common_bc7_pat_index, log_blk, dst_blk))
				return false;
		}
		else
		{
			// Only supports 1 or 2 partitions (or subsets)
			return false;
		}

		return true;
	}
			
	// ASTC 6x6 support
	namespace astc_6x6_hdr
	{
		const block_mode_desc g_block_mode_descs[TOTAL_BLOCK_MODE_DECS] =
		{
			// ------ mode 11
			{ false, 11, 1, 6, 6, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_3_LEVELS, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_3_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 11, 1, 6, 6, astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_80_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			{ false, 11, 1, 6, 5, astc_helpers::BISE_96_LEVELS, astc_helpers::BISE_5_LEVELS,  astc_helpers::BISE_96_LEVELS, astc_helpers::BISE_5_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 11, 1, 5, 6, astc_helpers::BISE_96_LEVELS, astc_helpers::BISE_5_LEVELS,  astc_helpers::BISE_96_LEVELS, astc_helpers::BISE_5_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			{ false, 11, 1, 6, 4, astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_8_LEVELS,   astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_8_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 11, 1, 4, 6, astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_8_LEVELS,   astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_8_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			{ false, 11, 1, 6, 3, astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_16_LEVELS,   astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_16_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 11, 1, 3, 6, astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_16_LEVELS,   astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_16_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			{ false, 11, 1, 5, 5, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_8_LEVELS,  astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_8_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 11, 1, 4, 4, astc_helpers::BISE_192_LEVELS, astc_helpers::BISE_16_LEVELS,  astc_helpers::BISE_192_LEVELS, astc_helpers::BISE_16_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			{ false, 11, 1, 3, 3, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_16_LEVELS, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_16_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			// ------ mode 7
			{ false, 7, 1, 6, 6, astc_helpers::BISE_96_LEVELS, astc_helpers::BISE_5_LEVELS,   astc_helpers::BISE_96_LEVELS,  astc_helpers::BISE_5_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			{ false, 7, 1, 6, 6, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_3_LEVELS,  astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_3_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 7, 1, 6, 6, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_4_LEVELS,  astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },

			{ false, 7, 1, 5, 6, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_6_LEVELS,   astc_helpers::BISE_256_LEVELS,  astc_helpers::BISE_6_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 7, 1, 6, 5, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_6_LEVELS,   astc_helpers::BISE_256_LEVELS,  astc_helpers::BISE_6_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },

			{ false, 7, 1, 3, 6, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_20_LEVELS,   astc_helpers::BISE_256_LEVELS,  astc_helpers::BISE_20_LEVELS, BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 7, 1, 6, 3, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_20_LEVELS,   astc_helpers::BISE_256_LEVELS,  astc_helpers::BISE_20_LEVELS, BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			// ------ mode 11, 2 subset
			{ false, 11, 2, 6, 6, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_2_LEVELS,  astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_2_LEVELS, BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			// 6x3/3x6
			{ false, 11, 2, 6, 3, astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_3_LEVELS,  astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_3_LEVELS, BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 11, 2, 3, 6, astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_3_LEVELS,  astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_3_LEVELS, BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			// 3x6/6x3
			{ false, 11, 2, 3, 6, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_4_LEVELS,  astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 11, 2, 6, 3, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_4_LEVELS,  astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			// 3x6/6x3
			{ false, 11, 2, 4, 6, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_3_LEVELS,  astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_3_LEVELS, 0, 0 },
			{ false, 11, 2, 6, 4, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_3_LEVELS,  astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_3_LEVELS, 0, 0 },

			// ------ mode 7, 2 subset

			// 6x5/5x6
			{ false, 7, 2, 5, 6, astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_3_LEVELS,   astc_helpers::BISE_80_LEVELS,  astc_helpers::BISE_3_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 7, 2, 6, 5, astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_3_LEVELS,   astc_helpers::BISE_80_LEVELS,  astc_helpers::BISE_3_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },

			// 6x4/4x6 mode 7
			{ false, 7, 2, 4, 6, astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_80_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 7, 2, 6, 4, astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_80_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },

			// 6x6
			{ false, 7, 2, 6, 6, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_3_LEVELS,   astc_helpers::BISE_32_LEVELS,  astc_helpers::BISE_3_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },

			// 6x6
			{ false, 7, 2, 6, 6, astc_helpers::BISE_192_LEVELS, astc_helpers::BISE_2_LEVELS,   astc_helpers::BISE_192_LEVELS,  astc_helpers::BISE_2_LEVELS, 0, 0 },

			// 5x5
			{ false, 7, 2, 5, 5, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_4_LEVELS, 0, 0 },

			// 6x3/3x6 mode 7
			{ false, 7, 2, 3, 6, astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_8_LEVELS,   astc_helpers::BISE_48_LEVELS,  astc_helpers::BISE_8_LEVELS, 0, 0 },
			{ false, 7, 2, 6, 3, astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_8_LEVELS,   astc_helpers::BISE_48_LEVELS,  astc_helpers::BISE_8_LEVELS, 0, 0 },

			// 6x3/3x6 mode 7
			{ false, 7, 2, 3, 6, astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_6_LEVELS,   astc_helpers::BISE_80_LEVELS,  astc_helpers::BISE_6_LEVELS, 0, 0 },
			{ false, 7, 2, 6, 3, astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_6_LEVELS,   astc_helpers::BISE_80_LEVELS,  astc_helpers::BISE_6_LEVELS, 0, 0 },

			// ------ dual plane

			// 3x6
			{ true, 11, 1, 3, 6, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ true, 11, 1, 3, 6, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 1 },
			{ true, 11, 1, 3, 6, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 2 },

			// 6x3
			{ true, 11, 1, 6, 3, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ true, 11, 1, 6, 3, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 1 },
			{ true, 11, 1, 6, 3, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 2 },

			// 3x3
			{ true, 11, 1, 3, 3, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_16_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_16_LEVELS, BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ true, 11, 1, 3, 3, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_16_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_16_LEVELS, BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 1 },
			{ true, 11, 1, 3, 3, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_16_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_16_LEVELS, BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 2 },

			// 4x4
			{ true, 11, 1, 4, 4, astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_5_LEVELS,   astc_helpers::BISE_48_LEVELS,  astc_helpers::BISE_5_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },
			{ true, 11, 1, 4, 4, astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_5_LEVELS,   astc_helpers::BISE_48_LEVELS,  astc_helpers::BISE_5_LEVELS, BASIST_HDR_6X6_LEVEL2, 1 },
			{ true, 11, 1, 4, 4, astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_5_LEVELS,   astc_helpers::BISE_48_LEVELS,  astc_helpers::BISE_5_LEVELS, BASIST_HDR_6X6_LEVEL2, 2 },

			// 5x5
			{ true, 11, 1, 5, 5, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_2_LEVELS,   astc_helpers::BISE_256_LEVELS,  astc_helpers::BISE_2_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },
			{ true, 11, 1, 5, 5, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_2_LEVELS,   astc_helpers::BISE_256_LEVELS,  astc_helpers::BISE_2_LEVELS, BASIST_HDR_6X6_LEVEL2, 1 },
			{ true, 11, 1, 5, 5, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_2_LEVELS,   astc_helpers::BISE_256_LEVELS,  astc_helpers::BISE_2_LEVELS, BASIST_HDR_6X6_LEVEL2, 2 },

			// ------ 2x2 modes for RDO
			// note 2x2 modes will be upsampled to 4x4 during transcoding (the min # of weight bits is 7 in ASTC)
			{ true, 11, 1, 2, 2, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_256_LEVELS,  astc_helpers::BISE_8_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ true, 11, 1, 2, 2, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_256_LEVELS,  astc_helpers::BISE_8_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 1 },
			{ true, 11, 1, 2, 2, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_256_LEVELS,  astc_helpers::BISE_8_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 2 },
			{ false, 11, 1, 2, 2, astc_helpers::BISE_128_LEVELS, astc_helpers::BISE_2_LEVELS,   astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_3_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			// ------ 3 subsets

			// 6x6
			{ false, 7, 3, 6, 6, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_2_LEVELS,   astc_helpers::BISE_32_LEVELS,  astc_helpers::BISE_2_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },

			// 5x5
			{ false, 7, 3, 5, 5, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_2_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_2_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },

			// 4x4
			{ false, 7, 3, 4, 4, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_3_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_3_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 7, 3, 4, 4, astc_helpers::BISE_40_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_40_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 7, 3, 4, 4, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_5_LEVELS,   astc_helpers::BISE_32_LEVELS,  astc_helpers::BISE_5_LEVELS, 0, 0 },

			// 3x3
			{ false, 7, 3, 3, 3, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_8_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_8_LEVELS, 0, 0 },

			// 6x4 
			{ false, 7, 3, 6, 4, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_2_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_2_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 7, 3, 4, 6, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_2_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_2_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },

			// 6x4
			{ false, 7, 3, 6, 4, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_3_LEVELS,   astc_helpers::BISE_32_LEVELS,  astc_helpers::BISE_3_LEVELS, 0, 0 },
			{ false, 7, 3, 4, 6, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_3_LEVELS,   astc_helpers::BISE_32_LEVELS,  astc_helpers::BISE_3_LEVELS, 0, 0 },

			// 6x5
			{ false, 7, 3, 6, 5, astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_2_LEVELS,   astc_helpers::BISE_48_LEVELS,  astc_helpers::BISE_2_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 7, 3, 5, 6, astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_2_LEVELS,   astc_helpers::BISE_48_LEVELS,  astc_helpers::BISE_2_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },

			// 6x3
			{ false, 7, 3, 6, 3, astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_3_LEVELS,   astc_helpers::BISE_48_LEVELS,  astc_helpers::BISE_3_LEVELS, 0, 0 },
			{ false, 7, 3, 3, 6, astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_3_LEVELS,   astc_helpers::BISE_48_LEVELS,  astc_helpers::BISE_3_LEVELS, 0, 0 },

			// 6x3
			{ false, 7, 3, 6, 3, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_32_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 7, 3, 3, 6, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_32_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },

			// 6x3
			{ false, 7, 3, 6, 3, astc_helpers::BISE_24_LEVELS, astc_helpers::BISE_5_LEVELS,   astc_helpers::BISE_24_LEVELS,  astc_helpers::BISE_5_LEVELS, 0, 0 },
			{ false, 7, 3, 3, 6, astc_helpers::BISE_24_LEVELS, astc_helpers::BISE_5_LEVELS,   astc_helpers::BISE_24_LEVELS,  astc_helpers::BISE_5_LEVELS, 0, 0 },

			// 5x4
			{ false, 7, 3, 5, 4, astc_helpers::BISE_40_LEVELS, astc_helpers::BISE_3_LEVELS,   astc_helpers::BISE_40_LEVELS,  astc_helpers::BISE_3_LEVELS, 0, 0 },
			{ false, 7, 3, 4, 5, astc_helpers::BISE_40_LEVELS, astc_helpers::BISE_3_LEVELS,   astc_helpers::BISE_40_LEVELS,  astc_helpers::BISE_3_LEVELS, 0, 0 },
		};
						
		const reuse_xy_delta g_reuse_xy_deltas[NUM_REUSE_XY_DELTAS] =
		{
			{ -1, 0 }, { -2, 0 }, { -3, 0 }, { -4, 0 },
			{ 3, -1 }, { 2, -1 }, { 1, -1 }, { 0, -1 }, { -1, -1 }, { -2, -1 }, { -3, -1 }, { -4, -1 },
			{ 3, -2 }, { 2, -2 }, { 1, -2 }, { 0, -2 }, { -1, -2 }, { -2, -2 }, { -3, -2 }, { -4, -2 },
			{ 3, -3 }, { 2, -3 }, { 1, -3 }, { 0, -3 }, { -1, -3 }, { -2, -3 }, { -3, -3 }, { -4, -3 },
			{ 3, -4 }, { 2, -4 }, { 1, -4 }, { 0, -4 }
		};

		//--------------------------------------------------------------------------------------------------------------------------

		void requantize_astc_weights(uint32_t n, const uint8_t* pSrc_ise_vals, uint32_t from_ise_range, uint8_t* pDst_ise_vals, uint32_t to_ise_range)
		{
			if (from_ise_range == to_ise_range)
			{
				if (pDst_ise_vals != pSrc_ise_vals)
					memcpy(pDst_ise_vals, pSrc_ise_vals, n);
				return;
			}

			const auto& dequant_tab = astc_helpers::g_dequant_tables.get_weight_tab(from_ise_range).m_ISE_to_val;
			const auto& quant_tab = astc_helpers::g_dequant_tables.get_weight_tab(to_ise_range).m_val_to_ise;

			for (uint32_t i = 0; i < n; i++)
				pDst_ise_vals[i] = quant_tab[dequant_tab[pSrc_ise_vals[i]]];
		}

		//--------------------------------------------------------------------------------------------------------------------------

		inline int get_bit(
			int src_val, int src_bit)
		{
			assert(src_bit >= 0 && src_bit <= 31);
			int bit = (src_val >> src_bit) & 1;
			return bit;
		}

		inline void pack_bit(
			int& dst, int dst_bit,
			int src_val, int src_bit = 0)
		{
			assert(dst_bit >= 0 && dst_bit <= 31);
			int bit = get_bit(src_val, src_bit);
			dst |= (bit << dst_bit);
		}

		// Valid for weight ISE ranges 12-192 levels. Preserves upper 2 or 3 bits post-quantization.
		static uint8_t g_quantize_tables_preserve2[astc_helpers::TOTAL_ISE_RANGES - 1][256];
		static uint8_t g_quantize_tables_preserve3[astc_helpers::TOTAL_ISE_RANGES - 1][256];

		const uint32_t g_part2_unique_index_to_seed[NUM_UNIQUE_PARTITIONS2] =
		{
			86, 959, 936, 476, 1007, 672, 447, 423, 488, 422, 273, 65, 267, 786, 585, 195, 108, 731, 878, 812, 264, 125, 868, 581, 258, 390, 549, 872, 661, 352, 645, 543, 988, 
			906, 903, 616, 482, 529, 3, 286, 272, 303, 151, 504, 498, 260, 79, 66, 608, 769, 305, 610, 1014, 967, 835, 789, 7, 951, 691, 15, 763, 976, 438, 314, 601, 673, 177, 
			252, 615, 436, 220, 899, 623, 433, 674, 278, 797, 107, 847, 114, 470, 760, 821, 490, 329, 945, 387, 471, 225, 172, 83, 418, 966, 439, 316, 247, 43, 343, 625, 798, 
			1, 61, 73, 307, 136, 474, 42, 664, 1013, 249, 389, 227, 374, 121, 48, 538, 226, 309, 554, 802, 834, 335, 495, 10, 955, 461, 293, 508, 153, 101, 63, 139, 31, 687, 
			132, 174, 324, 545, 289, 39, 178, 594, 963, 854, 222, 323, 998, 964, 598, 475, 720, 1019, 983, 91, 703, 614, 394, 612, 281, 207, 930, 758, 586, 128, 517, 426, 306, 
			168, 713, 36, 458, 876, 368, 780, 5, 9, 214, 109, 553, 726, 175, 103, 753, 684, 44, 665, 53, 500, 367, 611, 119, 732, 639, 326, 203, 156, 686, 910, 255, 62, 392, 591, 
			112, 88, 213, 19, 1022, 478, 90, 486, 799, 702, 730, 414, 99, 1008, 142, 886, 373, 216, 69, 393, 299, 648, 415, 822, 912, 110, 567, 550, 693, 2, 138, 59, 271, 562, 295, 
			714, 719, 199, 893, 831, 1006, 662, 235, 262, 78, 51, 902, 298, 190, 169, 583, 347, 890, 958, 909, 49, 987, 696, 633, 480, 50, 764, 826, 1023, 1016, 437, 891, 774, 257, 
			724, 791, 526, 593, 690, 638, 858, 895, 794, 995, 130, 87, 877, 819, 318, 649, 376, 211, 284, 937, 370, 688, 229, 994, 115, 842, 60, 521, 95, 694, 804, 146, 754, 487, 55, 
			17, 770, 450, 223, 4, 137, 911, 236, 683, 523, 47, 181, 24, 270, 602, 736, 11, 355, 148, 351, 762, 1009, 16, 210, 619, 805, 874, 807, 887, 403, 999, 810, 27, 402, 551, 135, 
			778, 33, 409, 993, 71, 363, 159, 183, 77, 596, 670, 380, 968, 811, 404, 348, 539, 158, 578, 196, 621, 68, 530, 193, 100, 167, 919, 353, 366, 327, 643, 948, 518, 756, 801, 558, 
			28, 705, 116, 94, 898, 453, 622, 647, 231, 445, 652, 230, 191, 277, 292, 254, 198, 766, 386, 232, 29, 70, 942, 740, 291, 607, 411, 496, 839, 8, 675, 319, 742, 21, 547, 627, 716, 
			663, 23, 914, 631, 595, 499, 685, 950, 510, 54, 587, 432, 45, 646, 25, 122, 947, 171, 862, 441, 808, 722, 14, 74, 658, 129, 266, 1001, 534, 395, 527, 250, 206, 237, 67, 897, 634, 
			572, 569, 533, 37, 341, 89, 463, 419, 75, 134, 283, 943, 519, 362, 144, 681, 407, 954, 131, 455, 934, 46, 513, 339, 194, 361, 606, 852, 546, 655, 1015, 147, 506, 240, 56, 836, 76, 
			98, 600, 430, 388, 980, 695, 817, 279, 58, 215, 149, 170, 531, 870, 18, 727, 154, 26, 938, 929, 302, 697, 452, 218, 700, 524, 828, 751, 869, 217, 440, 354
		};

		const uint32_t g_part3_unique_index_to_seed[NUM_UNIQUE_PARTITIONS3] =
		{
			0, 8, 11, 14, 15, 17, 18, 19, 26, 31, 34, 35, 36, 38, 44, 47, 48, 49, 51, 56,
			59, 61, 70, 74, 76, 82, 88, 90, 96, 100, 103, 104, 108, 110, 111, 117, 122, 123,
			126, 127, 132, 133, 135, 139, 147, 150, 151, 152, 156, 157, 163, 166, 168, 171,
			175, 176, 179, 181, 182, 183, 186, 189, 192, 199, 203, 205, 207, 210, 214, 216,
			222, 247, 249, 250, 252, 254, 260, 261, 262, 263, 266, 272, 273, 275, 276, 288,
			291, 292, 293, 294, 297, 302, 309, 310, 313, 314, 318, 327, 328, 331, 335, 337,
			346, 356, 357, 358, 363, 365, 368, 378, 381, 384, 386, 390, 391, 392, 396, 397,
			398, 399, 401, 410, 411, 419, 427, 430, 431, 437, 439, 440, 451, 455, 457, 458,
			459, 460, 462, 468, 470, 471, 472, 474, 475, 477, 479, 482, 483, 488, 493, 495,
			496, 502, 503, 504, 507, 510, 511, 512, 515, 516, 518, 519, 522, 523, 525, 526,
			527, 538, 543, 544, 546, 547, 549, 550, 552, 553, 554, 562, 570, 578, 579, 581,
			582, 588, 589, 590, 593, 595, 600, 606, 611, 613, 618, 623, 625, 632, 637, 638,
			645, 646, 650, 651, 658, 659, 662, 666, 667, 669, 670, 678, 679, 685, 686, 687,
			688, 691, 694, 696, 698, 699, 700, 701, 703, 704, 707, 713, 714, 715, 717, 719,
			722, 724, 727, 730, 731, 734, 738, 739, 743, 747, 748, 750, 751, 753, 758, 760,
			764, 766, 769, 775, 776, 783, 784, 785, 787, 791, 793, 798, 799, 802, 804, 805,
			806, 807, 808, 809, 810, 813, 822, 823, 825, 831, 835, 837, 838, 839, 840, 842,
			845, 846, 848, 853, 854, 858, 859, 860, 866, 874, 882, 884, 887, 888, 892, 894,
			898, 902, 907, 914, 915, 918, 919, 922, 923, 925, 927, 931, 932, 937, 938, 940,
			943, 944, 945, 953, 955, 958, 959, 963, 966, 971, 974, 979, 990, 991, 998, 999,
			1007, 1010, 1011, 1012, 1015, 1020, 1023
		};

		static void init_quantize_tables()
		{
			for (uint32_t ise_range = astc_helpers::BISE_192_LEVELS; ise_range >= astc_helpers::BISE_12_LEVELS; ise_range--)
			{
				const uint32_t num_levels = astc_helpers::get_ise_levels(ise_range);
				const auto& ise_to_val_tab = astc_helpers::g_dequant_tables.get_endpoint_tab(ise_range).m_ISE_to_val;

				for (uint32_t desired_val = 0; desired_val < 256; desired_val++)
				{
					{
						uint32_t best_err = UINT32_MAX;
						int best_ise_val = -1;

						for (uint32_t ise_val = 0; ise_val < num_levels; ise_val++)
						{
							const uint32_t quant_val = ise_to_val_tab[ise_val];

							if ((quant_val & 0b11000000) != (desired_val & 0b11000000))
								continue;

							uint32_t err = basisu::squarei((int)quant_val - (int)desired_val);
							if (err < best_err)
							{
								best_err = err;
								best_ise_val = ise_val;
							}

						} // ise_val

						assert(best_ise_val != -1);

						g_quantize_tables_preserve2[ise_range][desired_val] = (uint8_t)best_ise_val;
					}

					{
						uint32_t best_err = UINT32_MAX;
						int best_ise_val = -1;

						for (uint32_t ise_val = 0; ise_val < num_levels; ise_val++)
						{
							const uint32_t quant_val = ise_to_val_tab[ise_val];

							if ((quant_val & 0b11100000) != (desired_val & 0b11100000))
								continue;

							uint32_t err = basisu::squarei((int)quant_val - (int)desired_val);
							if (err < best_err)
							{
								best_err = err;
								best_ise_val = ise_val;
							}

						} // ise_val

						assert(best_ise_val != -1);

						g_quantize_tables_preserve3[ise_range][desired_val] = (uint8_t)best_ise_val;
					}

				} // desired_val

#if 0
				for (uint32_t i = 0; i < 256; i++)
				{
					if (g_quantize_tables_preserve2[ise_range][i] != astc_helpers::g_dequant_tables.get_endpoint_tab(ise_range).m_val_to_ise[i])
					{
						fmt_printf("P2, Range: {}, {} vs. {}\n", ise_range, g_quantize_tables_preserve2[ise_range][i], astc_helpers::g_dequant_tables.get_endpoint_tab(ise_range).m_val_to_ise[i]);
					}

					if (g_quantize_tables_preserve3[ise_range][i] != astc_helpers::g_dequant_tables.get_endpoint_tab(ise_range).m_val_to_ise[i])
					{
						fmt_printf("P3, Range: {}, {} vs. {}\n", ise_range, g_quantize_tables_preserve3[ise_range][i], astc_helpers::g_dequant_tables.get_endpoint_tab(ise_range).m_val_to_ise[i]);
					}
				}
#endif

			} // ise_range
		}

		void requantize_ise_endpoints(uint32_t cem, uint32_t src_ise_endpoint_range, const uint8_t* pSrc_endpoints, uint32_t dst_ise_endpoint_range, uint8_t* pDst_endpoints)
		{
			assert(pSrc_endpoints != pDst_endpoints);
			assert((src_ise_endpoint_range >= astc_helpers::FIRST_VALID_ENDPOINT_ISE_RANGE) && (src_ise_endpoint_range <= astc_helpers::LAST_VALID_ENDPOINT_ISE_RANGE));
			assert((dst_ise_endpoint_range >= astc_helpers::FIRST_VALID_ENDPOINT_ISE_RANGE) && (dst_ise_endpoint_range <= astc_helpers::LAST_VALID_ENDPOINT_ISE_RANGE));

			// must be >=12 ISE levels for g_quantize_tables_preserve2 etc.
			assert(dst_ise_endpoint_range >= astc_helpers::BISE_12_LEVELS);

			const uint32_t n = (cem == 11) ? basist::NUM_MODE11_ENDPOINTS : basist::NUM_MODE7_ENDPOINTS;

			if (src_ise_endpoint_range == dst_ise_endpoint_range)
			{
				memcpy(pDst_endpoints, pSrc_endpoints, n);
				return;
			}

			uint8_t temp_endpoints[basist::NUM_MODE11_ENDPOINTS];
			if (src_ise_endpoint_range != astc_helpers::BISE_256_LEVELS)
			{
				assert(n <= basist::NUM_MODE11_ENDPOINTS);

				const auto& endpoint_dequant_tab = astc_helpers::g_dequant_tables.get_endpoint_tab(src_ise_endpoint_range).m_ISE_to_val;

				for (uint32_t i = 0; i < n; i++)
					temp_endpoints[i] = endpoint_dequant_tab[pSrc_endpoints[i]];

				pSrc_endpoints = temp_endpoints;
			}

			if (dst_ise_endpoint_range == astc_helpers::BISE_256_LEVELS)
			{
				memcpy(pDst_endpoints, pSrc_endpoints, n);
				return;
			}

			const auto& quant_tab = astc_helpers::g_dequant_tables.get_endpoint_tab(dst_ise_endpoint_range).m_val_to_ise;

			const auto& dequant_tab = astc_helpers::g_dequant_tables.get_endpoint_tab(dst_ise_endpoint_range).m_ISE_to_val;
			BASISU_NOTE_UNUSED(dequant_tab);

#if 1
			// A smarter value quantization that preserves the key upper bits. (If these bits get corrupted, the entire meaning of the encoding can get lost.)
			if (cem == 11)
			{
				assert(n == 6);

				int maj_comp = 0;
				pack_bit(maj_comp, 0, pSrc_endpoints[4], 7);
				pack_bit(maj_comp, 1, pSrc_endpoints[5], 7);

				if (maj_comp == 3)
				{
					// Direct
					pDst_endpoints[0] = quant_tab[pSrc_endpoints[0]];
					pDst_endpoints[1] = quant_tab[pSrc_endpoints[1]];
					pDst_endpoints[2] = quant_tab[pSrc_endpoints[2]];
					pDst_endpoints[3] = quant_tab[pSrc_endpoints[3]];
					// No need for preserve1 tables, we can use the regular quantization tables because they preserve the MSB.
					pDst_endpoints[4] = quant_tab[pSrc_endpoints[4]];
					pDst_endpoints[5] = quant_tab[pSrc_endpoints[5]];

					assert((dequant_tab[pDst_endpoints[4]] & 128) == (pSrc_endpoints[4] & 128));
					assert((dequant_tab[pDst_endpoints[5]] & 128) == (pSrc_endpoints[5] & 128));
				}
				else
				{
					pDst_endpoints[0] = quant_tab[pSrc_endpoints[0]];
					pDst_endpoints[1] = g_quantize_tables_preserve2[dst_ise_endpoint_range][pSrc_endpoints[1]];
					pDst_endpoints[2] = g_quantize_tables_preserve2[dst_ise_endpoint_range][pSrc_endpoints[2]];
					pDst_endpoints[3] = g_quantize_tables_preserve2[dst_ise_endpoint_range][pSrc_endpoints[3]];
					pDst_endpoints[4] = g_quantize_tables_preserve3[dst_ise_endpoint_range][pSrc_endpoints[4]];
					pDst_endpoints[5] = g_quantize_tables_preserve3[dst_ise_endpoint_range][pSrc_endpoints[5]];

					assert((dequant_tab[pDst_endpoints[1]] & 0b11000000) == (pSrc_endpoints[1] & 0b11000000));
					assert((dequant_tab[pDst_endpoints[2]] & 0b11000000) == (pSrc_endpoints[2] & 0b11000000));
					assert((dequant_tab[pDst_endpoints[3]] & 0b11000000) == (pSrc_endpoints[3] & 0b11000000));
					assert((dequant_tab[pDst_endpoints[4]] & 0b11100000) == (pSrc_endpoints[4] & 0b11100000));
					assert((dequant_tab[pDst_endpoints[5]] & 0b11100000) == (pSrc_endpoints[5] & 0b11100000));
				}
			}
			else if (cem == 7)
			{
				assert(n == 4);

				pDst_endpoints[0] = g_quantize_tables_preserve2[dst_ise_endpoint_range][pSrc_endpoints[0]];
				pDst_endpoints[1] = g_quantize_tables_preserve3[dst_ise_endpoint_range][pSrc_endpoints[1]];
				pDst_endpoints[2] = g_quantize_tables_preserve3[dst_ise_endpoint_range][pSrc_endpoints[2]];
				pDst_endpoints[3] = g_quantize_tables_preserve3[dst_ise_endpoint_range][pSrc_endpoints[3]];

				assert((dequant_tab[pDst_endpoints[0]] & 0b11000000) == (pSrc_endpoints[0] & 0b11000000));
				assert((dequant_tab[pDst_endpoints[1]] & 0b11100000) == (pSrc_endpoints[1] & 0b11100000));
				assert((dequant_tab[pDst_endpoints[2]] & 0b11100000) == (pSrc_endpoints[2] & 0b11100000));
				assert((dequant_tab[pDst_endpoints[3]] & 0b11100000) == (pSrc_endpoints[3] & 0b11100000));
			}
			else
			{
				assert(0);
			}
#else
			for (uint32_t i = 0; i < n; i++)
			{
				uint32_t v = pSrc_endpoints[i];
				assert(v <= 255);

				pDst_endpoints[i] = quant_tab[v];
			}
#endif
		}

		void copy_weight_grid(bool dual_plane, uint32_t grid_x, uint32_t grid_y, const uint8_t* transcode_weights, astc_helpers::log_astc_block& decomp_blk)
		{
			assert(decomp_blk.m_weight_ise_range >= astc_helpers::BISE_2_LEVELS);
			assert(decomp_blk.m_weight_ise_range <= astc_helpers::BISE_32_LEVELS);

			// Special case for 2x2 which isn't typically valid ASTC (too few weight bits without dual plane). Upsample to 4x4.
			if ((!dual_plane) && (grid_x == 2) && (grid_y == 2))
			{
				decomp_blk.m_grid_width = 4;
				decomp_blk.m_grid_height = 4;

				//const uint32_t total_weight_levels = astc_helpers::bise_levels(decomp_blk.m_weight_ise_range);
				const auto& dequant_weight = astc_helpers::g_dequant_tables.get_weight_tab(decomp_blk.m_weight_ise_range).m_ISE_to_val;
				const auto& quant_weight = astc_helpers::g_dequant_tables.get_weight_tab(decomp_blk.m_weight_ise_range).m_val_to_ise;

				astc_helpers::weighted_sample weights[16];

				compute_upsample_weights(4, 4, 2, 2, weights);

				for (uint32_t y = 0; y < 4; y++)
				{
					for (uint32_t x = 0; x < 4; x++)
					{
						const astc_helpers::weighted_sample& sample = weights[x + y * 4];

						uint32_t total_weight = 8;

						for (uint32_t yo = 0; yo < 2; yo++)
						{
							for (uint32_t xo = 0; xo < 2; xo++)
							{
								if (!sample.m_weights[yo][xo])
									continue;

								total_weight += dequant_weight[transcode_weights[basisu::in_bounds((x + xo) + (y + yo) * grid_x, 0, grid_x * grid_y)]] * sample.m_weights[yo][xo];
							} // x
						} // y

						total_weight >>= 4;

						assert(total_weight <= 64);

						decomp_blk.m_weights[x + y * 4] = quant_weight[total_weight];
					}
				}
			}
			else
			{
				const uint32_t num_planes = dual_plane ? 2 : 1;

				decomp_blk.m_grid_width = (uint8_t)grid_x;
				decomp_blk.m_grid_height = (uint8_t)grid_y;
				memcpy(decomp_blk.m_weights, transcode_weights, grid_x * grid_y * num_planes);
			}
		}

		// cur_y is the current destination row
		// prev_y is the row we want to access
		static inline int calc_row_index(int cur_y, int prev_y, int cur_row_index)
		{
			assert((cur_y >= 0) && (prev_y >= 0));
			assert((cur_row_index >= 0) && (cur_row_index < REUSE_MAX_BUFFER_ROWS));

			int delta_y = prev_y - cur_y;
			assert((delta_y > -REUSE_MAX_BUFFER_ROWS) && (delta_y <= 0));

			cur_row_index += delta_y;
			if (cur_row_index < 0)
				cur_row_index += REUSE_MAX_BUFFER_ROWS;

			assert((cur_row_index >= 0) && (cur_row_index < REUSE_MAX_BUFFER_ROWS));

			return cur_row_index;
		}

		bool decode_values(basist::bitwise_decoder& decoder, uint32_t total_values, uint32_t ise_range, uint8_t* pValues)
		{
			assert(ise_range <= astc_helpers::BISE_256_LEVELS);

			const uint32_t ep_bits = astc_helpers::g_ise_range_table[ise_range][0];
			const uint32_t ep_trits = astc_helpers::g_ise_range_table[ise_range][1];
			const uint32_t ep_quints = astc_helpers::g_ise_range_table[ise_range][2];

			uint32_t total_tqs = 0;
			uint32_t bundle_size = 0, mul = 0;
			if (ep_trits)
			{
				total_tqs = (total_values + 4) / 5;
				bundle_size = 5;
				mul = 3;
			}
			else if (ep_quints)
			{
				total_tqs = (total_values + 2) / 3;
				bundle_size = 3;
				mul = 5;
			}

			const uint32_t MAX_TQ_VALUES = 32;
			assert(total_tqs <= MAX_TQ_VALUES);
			uint32_t tq_values[MAX_TQ_VALUES];

			for (uint32_t i = 0; i < total_tqs; i++)
			{
				uint32_t num_bits = ep_trits ? 8 : 7;

				if (i == (total_tqs - 1))
				{
					uint32_t num_remaining = total_values - (total_tqs - 1) * bundle_size;
					if (ep_trits)
					{
						switch (num_remaining)
						{
						case 1: num_bits = 2; break;
						case 2: num_bits = 4; break;
						case 3: num_bits = 5; break;
						case 4: num_bits = 7; break;
						default: break;
						}
					}
					else if (ep_quints)
					{
						switch (num_remaining)
						{
						case 1: num_bits = 3; break;
						case 2: num_bits = 5; break;
						default: break;
						}
					}
				}

				tq_values[i] = (uint32_t)decoder.get_bits(num_bits);
			} // i

			uint32_t accum = 0;
			uint32_t accum_remaining = 0;
			uint32_t next_tq_index = 0;

			for (uint32_t i = 0; i < total_values; i++)
			{
				uint32_t value = (uint32_t)decoder.get_bits(ep_bits);

				if (total_tqs)
				{
					if (!accum_remaining)
					{
						assert(next_tq_index < total_tqs);
						accum = tq_values[next_tq_index++];
						accum_remaining = bundle_size;
					}

					uint32_t v = accum % mul;
					accum /= mul;
					accum_remaining--;

					value |= (v << ep_bits);
				}

				pValues[i] = (uint8_t)value;
			}

			return true;
		}

		static inline uint32_t get_num_endpoint_vals(uint32_t cem)
		{
			assert((cem == 7) || (cem == 11));
			return (cem == 11) ? basist::NUM_MODE11_ENDPOINTS : basist::NUM_MODE7_ENDPOINTS;
		}
				
		const uint32_t g_bc6h_weights4[16] = { 0, 4, 9, 13, 17, 21, 26, 30, 34, 38, 43, 47, 51, 55, 60, 64 };

#if 0
		static BASISU_FORCE_INLINE int pos_lrintf(float x)
		{
			assert(x >= 0.0f);
			return (int)(x + .5f);
		}

		static BASISU_FORCE_INLINE basist::half_float fast_float_to_half_non_neg_no_nan_inf(float val)
		{
			union { float f; int32_t i; uint32_t u; } fi = { val };
			const int flt_m = fi.i & 0x7FFFFF, flt_e = (fi.i >> 23) & 0xFF;
			int e = 0, m = 0;

			assert(((fi.i >> 31) == 0) && (flt_e != 0xFF));

			// not zero or denormal
			if (flt_e != 0)
			{
				int new_exp = flt_e - 127;
				if (new_exp > 15)
					e = 31;
				else if (new_exp < -14)
					m = pos_lrintf((1 << 24) * fabsf(fi.f));
				else
				{
					e = new_exp + 15;
					m = pos_lrintf(flt_m * (1.0f / ((float)(1 << 13))));
				}
			}

			assert((0 <= m) && (m <= 1024));
			if (m == 1024)
			{
				e++;
				m = 0;
			}

			assert((e >= 0) && (e <= 31));
			assert((m >= 0) && (m <= 1023));

			basist::half_float result = (basist::half_float)((e << 10) | m);
			return result;
		}
#endif

		union fu32
		{
			uint32_t u;
			float f;
		};

		static BASISU_FORCE_INLINE basist::half_float fast_float_to_half_no_clamp_neg_nan_or_inf(float f)
		{
			assert(!isnan(f) && !isinf(f));
			assert((f >= 0.0f) && (f <= basist::MAX_HALF_FLOAT));

			// Sutract 112 from the exponent, to change the bias from 127 to 15.
			static const fu32 g_f_to_h{ 0x7800000 };

			fu32 fu;

			fu.f = f * g_f_to_h.f;

			uint32_t h = (basist::half_float)((fu.u >> (23 - 10)) & 0x7FFF);

			// round to even
			uint32_t mant = fu.u & 8191; // examine lowest 13 bits
			h += (mant > 4096);

			if (h > basist::MAX_HALF_FLOAT_AS_INT_BITS)
				h = basist::MAX_HALF_FLOAT_AS_INT_BITS;

			return (basist::half_float)h;
		}

		static BASISU_FORCE_INLINE float ftoh(float f)
		{
			//float res = (float)fast_float_to_half_non_neg_no_nan_inf(fabsf(f)) * ((f < 0.0f) ? -1.0f : 1.0f);
			float res = (float)fast_float_to_half_no_clamp_neg_nan_or_inf(fabsf(f)) * ((f < 0.0f) ? -1.0f : 1.0f);
			return res;
		}
		
		// Supports positive and denormals only. No NaN or Inf.
		static BASISU_FORCE_INLINE float fast_half_to_float_pos_not_inf_or_nan(basist::half_float h)
		{
			assert(!basist::half_is_signed(h) && !basist::is_half_inf_or_nan(h));

			// add 112 to the exponent (112+half float's exp bias of 15=float32's bias of 127)
			static const fu32 K = { 0x77800000 };

			fu32 o;
			o.u = h << 13;
			o.f *= K.f;

			return o.f;
		}

		static BASISU_FORCE_INLINE float inv_sqrt(float v)
		{
			union
			{
				float flt;
				uint32_t ui;
			} un;

			un.flt = v;
			un.ui = 0x5F1FFFF9UL - (un.ui >> 1);

			return 0.703952253f * un.flt * (2.38924456f - v * (un.flt * un.flt));
		}

		static const int FAST_BC6H_STD_DEV_THRESH = 256;
		static const int FAST_BC6H_COMPLEX_STD_DEV_THRESH = 512;
		static const int FAST_BC6H_VERY_COMPLEX_STD_DEV_THRESH = 2048;

		static void assign_weights_simple_4(
			const basist::half_float* pPixels,
			uint8_t* pWeights,
			int min_r, int min_g, int min_b,
			int max_r, int max_g, int max_b, int64_t block_max_var)
		{
			BASISU_NOTE_UNUSED(block_max_var);
			
			float fmin_r = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)min_r);
			float fmin_g = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)min_g);
			float fmin_b = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)min_b);

			float fmax_r = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)max_r);
			float fmax_g = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)max_g);
			float fmax_b = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)max_b);

			float fdir_r = fmax_r - fmin_r;
			float fdir_g = fmax_g - fmin_g;
			float fdir_b = fmax_b - fmin_b;

			float l = inv_sqrt(fdir_r * fdir_r + fdir_g * fdir_g + fdir_b * fdir_b);
			if (l != 0.0f)
			{
				fdir_r *= l;
				fdir_g *= l;
				fdir_b *= l;
			}

			float lr = ftoh(fmin_r * fdir_r + fmin_g * fdir_g + fmin_b * fdir_b);
			float hr = ftoh(fmax_r * fdir_r + fmax_g * fdir_g + fmax_b * fdir_b);

			float frr = (hr == lr) ? 0.0f : (14.93333f / (float)(hr - lr));

			lr = (-lr * frr) + 0.53333f;
			for (uint32_t i = 0; i < 16; i++)
			{
				const float r = fast_half_to_float_pos_not_inf_or_nan(pPixels[i * 3 + 0]);
				const float g = fast_half_to_float_pos_not_inf_or_nan(pPixels[i * 3 + 1]);
				const float b = fast_half_to_float_pos_not_inf_or_nan(pPixels[i * 3 + 2]);
				const float w = ftoh(r * fdir_r + g * fdir_g + b * fdir_b);

				pWeights[i] = (uint8_t)basisu::clamp((int)(w * frr + lr), 0, 15);
			}
		}
		
		static double assign_weights_4(
			const vec3F* pFloat_pixels, const float* pPixel_scales,
			uint8_t* pWeights,
			int min_r, int min_g, int min_b,
			int max_r, int max_g, int max_b, int64_t block_max_var, bool try_2subsets_flag, 
			const fast_bc6h_params& params)
		{
			float cr[16], cg[16], cb[16];

			for (uint32_t i = 0; i < 16; i++)
			{
				const uint32_t w = g_bc6h_weights4[i];

				cr[i] = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)((min_r * (64 - w) + max_r * w + 32) >> 6));
				cg[i] = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)((min_g * (64 - w) + max_g * w + 32) >> 6));
				cb[i] = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)((min_b * (64 - w) + max_b * w + 32) >> 6));
			}

			double total_err = 0.0f;

			if (params.m_brute_force_weight4_assignment)
			{
				for (uint32_t i = 0; i < 16; i++)
				{
					const float qr = pFloat_pixels[i].c[0], qg = pFloat_pixels[i].c[1], qb = pFloat_pixels[i].c[2];

					float best_err = basisu::squaref(cr[0] - qr) + basisu::squaref(cg[0] - qg) + basisu::squaref(cb[0] - qb);
					uint32_t best_idx = 0;

					for (uint32_t j = 1; j < 16; j++)
					{
						float rd = cr[j] - qr, gd = cg[j] - qg, bd = cb[j] - qb;
						float e = rd * rd + gd * gd + bd * bd;

						if (e < best_err)
						{
							best_err = e;
							best_idx = j;
						}
					}

					pWeights[i] = (uint8_t)best_idx;

					total_err += best_err * pPixel_scales[i];
				}
			}
			else
			{
				const float dir_r = cr[15] - cr[0], dir_g = cg[15] - cg[0], dir_b = cb[15] - cb[0];

				float dots[16];
				for (uint32_t i = 0; i < 16; i++)
					dots[i] = cr[i] * dir_r + cg[i] * dir_g + cb[i] * dir_b;

				float mid_dots[15];
				bool monotonically_increasing = true;
				for (uint32_t i = 0; i < 15; i++)
				{
					mid_dots[i] = (dots[i] + dots[i + 1]) * .5f;

					if (dots[i] > dots[i + 1])
						monotonically_increasing = false;
				}

				const bool check_more_colors = block_max_var > (FAST_BC6H_VERY_COMPLEX_STD_DEV_THRESH * FAST_BC6H_VERY_COMPLEX_STD_DEV_THRESH * 16); // watch prec

				if (!monotonically_increasing)
				{
					// Seems very rare, not worth optimizing the other cases
					for (uint32_t i = 0; i < 16; i++)
					{
						const float qr = pFloat_pixels[i].c[0], qg = pFloat_pixels[i].c[1], qb = pFloat_pixels[i].c[2];

						float d = qr * dir_r + qg * dir_g + qb * dir_b;

						float best_e = fabsf(d - dots[0]);
						int best_idx = 0;

						for (int j = 1; j < 16; j++)
						{
							float e = fabsf(d - dots[j]);
							if (e < best_e)
							{
								best_e = e;
								best_idx = j;
							}
						}

						assert((best_idx >= 0) && (best_idx <= 15));

						pWeights[i] = (uint8_t)best_idx;

						float err = basisu::squaref(qr - cr[best_idx]) + basisu::squaref(qg - cg[best_idx]) + basisu::squaref(qb - cb[best_idx]);
						total_err += err * pPixel_scales[i];
					}
				}
				else if ((!try_2subsets_flag) || (!check_more_colors))
				{
					for (uint32_t i = 0; i < 16; i++)
					{
						const float qr = pFloat_pixels[i].c[0], qg = pFloat_pixels[i].c[1], qb = pFloat_pixels[i].c[2];

						uint32_t best_idx = 0;

						float d = qr * dir_r + qg * dir_g + qb * dir_b;

						int low = 0;

						int mid = low + 7;
						if (d >= mid_dots[mid]) low = mid + 1;
						mid = low + 3;
						if (d >= mid_dots[mid]) low = mid + 1;
						mid = low + 1;
						if (d >= mid_dots[mid]) low = mid + 1;
						mid = low;
						if (d >= mid_dots[mid]) low = mid + 1;

						best_idx = low;
						assert((best_idx >= 0) && (best_idx <= 15));

						pWeights[i] = (uint8_t)best_idx;

						// Giesen's MRSSE (Mean Relative Sum of Squared Errors). 
						// Our ASTC HDR encoder uses slightly slower approx. MSLE, and it's too late/risky to eval the difference vs. MRSSE on the larger ASTC HDR blocks.
						float err = basisu::squaref(qr - cr[best_idx]) + basisu::squaref(qg - cg[best_idx]) + basisu::squaref(qb - cb[best_idx]);
						total_err += err * pPixel_scales[i];
					}
				}
				else
				{
					for (uint32_t i = 0; i < 16; i++)
					{
						const float qr = pFloat_pixels[i].c[0], qg = pFloat_pixels[i].c[1], qb = pFloat_pixels[i].c[2];

						uint32_t best_idx = 0;

						float d = qr * dir_r + qg * dir_g + qb * dir_b;

						int low = 0;

						int mid = low + 7;
						if (d >= mid_dots[mid]) low = mid + 1;
						mid = low + 3;
						if (d >= mid_dots[mid]) low = mid + 1;
						mid = low + 1;
						if (d >= mid_dots[mid]) low = mid + 1;
						mid = low;
						if (d >= mid_dots[mid]) low = mid + 1;

						best_idx = low;
						assert((best_idx >= 0) && (best_idx <= 15));

						float err = basisu::squaref(qr - cr[best_idx]) + basisu::squaref(qg - cg[best_idx]) + basisu::squaref(qb - cb[best_idx]);

						{
							int alt_idx = best_idx + 1;
							if (alt_idx > 15)
								alt_idx = 13;

							float alt_err = basisu::squaref(qr - cr[alt_idx]) + basisu::squaref(qg - cg[alt_idx]) + basisu::squaref(qb - cb[alt_idx]);
							if (alt_err < err)
							{
								err = alt_err;
								best_idx = alt_idx;
							}
						}

						{
							int alt_idx2 = best_idx - 1;
							if (alt_idx2 < 0)
								alt_idx2 = 2;
							float alt_err2 = basisu::squaref(qr - cr[alt_idx2]) + basisu::squaref(qg - cg[alt_idx2]) + basisu::squaref(qb - cb[alt_idx2]);
							if (alt_err2 < err)
							{
								err = alt_err2;
								best_idx = alt_idx2;
							}
						}

						pWeights[i] = (uint8_t)best_idx;

						total_err += err * pPixel_scales[i];
					}
				}
			}

			return total_err;
		}

		static void assign_weights3(uint8_t trial_weights[16],
			uint32_t best_pat_bits,
			uint32_t subset_min_r[2], uint32_t subset_min_g[2], uint32_t subset_min_b[2],
			uint32_t subset_max_r[2], uint32_t subset_max_g[2], uint32_t subset_max_b[2],
			const vec3F* pFloat_pixels)
		{
			float subset_cr[2][8], subset_cg[2][8], subset_cb[2][8];

			for (uint32_t subset = 0; subset < 2; subset++)
			{
				const uint32_t min_r = subset_min_r[subset], min_g = subset_min_g[subset], min_b = subset_min_b[subset];
				const uint32_t max_r = subset_max_r[subset], max_g = subset_max_g[subset], max_b = subset_max_b[subset];

				for (uint32_t j = 0; j < 8; j++)
				{
					const uint32_t w = g_bc7_weights3[j];

					subset_cr[subset][j] = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)((min_r * (64 - w) + max_r * w + 32) >> 6));
					subset_cg[subset][j] = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)((min_g * (64 - w) + max_g * w + 32) >> 6));
					subset_cb[subset][j] = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)((min_b * (64 - w) + max_b * w + 32) >> 6));
				} // j

			} // subset

			// TODO: Plane optimization?

			for (uint32_t i = 0; i < 16; i++)
			{
				const uint32_t subset = (best_pat_bits >> i) & 1;
				const float qr = pFloat_pixels[i].c[0], qg = pFloat_pixels[i].c[1], qb = pFloat_pixels[i].c[2];

				float best_error = basisu::squaref(subset_cr[subset][0] - qr) + basisu::squaref(subset_cg[subset][0] - qg) + basisu::squaref(subset_cb[subset][0] - qb);
				uint32_t best_idx = 0;
								
				for (uint32_t j = 1; j < 8; j++)
				{
					float e = basisu::squaref(subset_cr[subset][j] - qr) + basisu::squaref(subset_cg[subset][j] - qg) + basisu::squaref(subset_cb[subset][j] - qb);
					if (e < best_error)
					{
						best_error = e;
						best_idx = j;
					}
				}

				trial_weights[i] = (uint8_t)best_idx;

			} // i
		}

		static double assign_weights_error_3(uint8_t trial_weights[16],
			uint32_t best_pat_bits,
			uint32_t subset_min_r[2], uint32_t subset_min_g[2], uint32_t subset_min_b[2],
			uint32_t subset_max_r[2], uint32_t subset_max_g[2], uint32_t subset_max_b[2],
			const vec3F* pFloat_pixels, const float* pPixel_scales)
		{
			float subset_cr[2][8], subset_cg[2][8], subset_cb[2][8];

			for (uint32_t subset = 0; subset < 2; subset++)
			{
				const uint32_t min_r = subset_min_r[subset], min_g = subset_min_g[subset], min_b = subset_min_b[subset];
				const uint32_t max_r = subset_max_r[subset], max_g = subset_max_g[subset], max_b = subset_max_b[subset];

				for (uint32_t j = 0; j < 8; j++)
				{
					const uint32_t w = g_bc7_weights3[j];

					subset_cr[subset][j] = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)((min_r * (64 - w) + max_r * w + 32) >> 6));
					subset_cg[subset][j] = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)((min_g * (64 - w) + max_g * w + 32) >> 6));
					subset_cb[subset][j] = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)((min_b * (64 - w) + max_b * w + 32) >> 6));
				} // j

			} // subset

			double trial_error = 0.0f;

			// TODO: Plane optimization?

			for (uint32_t i = 0; i < 16; i++)
			{
				const uint32_t subset = (best_pat_bits >> i) & 1;
				const float qr = pFloat_pixels[i].c[0], qg = pFloat_pixels[i].c[1], qb = pFloat_pixels[i].c[2];

				float best_error = basisu::squaref(subset_cr[subset][0] - qr) + basisu::squaref(subset_cg[subset][0] - qg) + basisu::squaref(subset_cb[subset][0] - qb);
				uint32_t best_idx = 0;

				for (uint32_t j = 1; j < 8; j++)
				{
					float e = basisu::squaref(subset_cr[subset][j] - qr) + basisu::squaref(subset_cg[subset][j] - qg) + basisu::squaref(subset_cb[subset][j] - qb);
					if (e < best_error)
					{
						best_error = e;
						best_idx = j;
					}
				}

				trial_weights[i] = (uint8_t)best_idx;

				trial_error += best_error * pPixel_scales[i];

			} // i

			return trial_error;
		}

		static basist::vec4F g_bc6h_ls_weights_3[8];
		static basist::vec4F g_bc6h_ls_weights_4[16];
				
		const uint32_t BC6H_NUM_PATS = 32;
		static uint32_t g_bc6h_pats2[BC6H_NUM_PATS];

		static void fast_encode_bc6h_init()
		{
			for (uint32_t i = 0; i < 8; i++)
			{
				const float w = (float)g_bc7_weights3[i] * (1.0f / 64.0f);
				g_bc6h_ls_weights_3[i].set(w * w, (1.0f - w) * w, (1.0f - w) * (1.0f - w), w);
			}

			for (uint32_t i = 0; i < 16; i++)
			{
				const float w = (float)g_bc6h_weights4[i] * (1.0f / 64.0f);
				g_bc6h_ls_weights_4[i].set(w * w, (1.0f - w) * w, (1.0f - w) * (1.0f - w), w);
			}

			for (uint32_t pat_index = 0; pat_index < BC6H_NUM_PATS; pat_index++)
			{
				uint32_t pat_bits = 0;

				for (uint32_t j = 0; j < 16; j++)
					pat_bits |= (g_bc7_partition2[pat_index * 16 + j] << j);

				g_bc6h_pats2[pat_index] = pat_bits;
			}
		}

		static int bc6h_dequantize(int val, int bits)
		{
			assert(val < (1 << bits));

			int result;
			if (bits >= 15)
				result = val;
			else if (!val)
				result = 0;
			else if (val == ((1 << bits) - 1))
				result = 0xFFFF;
			else
				result = ((val << 16) + 0x8000) >> bits;
			return result;
		}

		static inline basist::half_float bc6h_convert_to_half(int val)
		{
			assert(val < 65536);

			// scale by 31/64
			return (basist::half_float)((val * 31) >> 6);
		}

		static void bc6h_quant_dequant_endpoints(uint32_t& min_r, uint32_t& min_g, uint32_t& min_b, uint32_t& max_r, uint32_t& max_g, uint32_t& max_b, int bits) // bits=10
		{
			min_r = bc6h_convert_to_half(bc6h_dequantize(basist::bc6h_half_to_blog((basist::half_float)min_r, bits), bits));
			min_g = bc6h_convert_to_half(bc6h_dequantize(basist::bc6h_half_to_blog((basist::half_float)min_g, bits), bits));
			min_b = bc6h_convert_to_half(bc6h_dequantize(basist::bc6h_half_to_blog((basist::half_float)min_b, bits), bits));

			max_r = bc6h_convert_to_half(bc6h_dequantize(basist::bc6h_half_to_blog((basist::half_float)max_r, bits), bits));
			max_g = bc6h_convert_to_half(bc6h_dequantize(basist::bc6h_half_to_blog((basist::half_float)max_g, bits), bits));
			max_b = bc6h_convert_to_half(bc6h_dequantize(basist::bc6h_half_to_blog((basist::half_float)max_b, bits), bits));
		}

		static void bc6h_quant_endpoints(
			uint32_t min_hr, uint32_t min_hg, uint32_t min_hb, uint32_t max_hr, uint32_t max_hg, uint32_t max_hb,
			uint32_t& min_r, uint32_t& min_g, uint32_t& min_b, uint32_t& max_r, uint32_t& max_g, uint32_t& max_b, 
			int bits)
		{
			min_r = basist::bc6h_half_to_blog((basist::half_float)min_hr, bits);
			min_g = basist::bc6h_half_to_blog((basist::half_float)min_hg, bits);
			min_b = basist::bc6h_half_to_blog((basist::half_float)min_hb, bits);

			max_r = basist::bc6h_half_to_blog((basist::half_float)max_hr, bits);
			max_g = basist::bc6h_half_to_blog((basist::half_float)max_hg, bits);
			max_b = basist::bc6h_half_to_blog((basist::half_float)max_hb, bits);
		}

		static void bc6h_dequant_endpoints(
			uint32_t min_br, uint32_t min_bg, uint32_t min_bb, uint32_t max_br, uint32_t max_bg, uint32_t max_bb,
			uint32_t& min_hr, uint32_t& min_hg, uint32_t& min_hb, uint32_t& max_hr, uint32_t& max_hg, uint32_t& max_hb,
			int bits)
		{
			min_hr = bc6h_convert_to_half(bc6h_dequantize(min_br, bits));
			min_hg = bc6h_convert_to_half(bc6h_dequantize(min_bg, bits));
			min_hb = bc6h_convert_to_half(bc6h_dequantize(min_bb, bits));

			max_hr = bc6h_convert_to_half(bc6h_dequantize(max_br, bits));
			max_hg = bc6h_convert_to_half(bc6h_dequantize(max_bg, bits));
			max_hb = bc6h_convert_to_half(bc6h_dequantize(max_bb, bits));
		}

		static BASISU_FORCE_INLINE int popcount32(uint32_t x) 
		{
#if defined(__EMSCRIPTEN__) || defined(__clang__) || defined(__GNUC__)
			return __builtin_popcount(x);
#elif defined(_MSC_VER)
			return __popcnt(x);
#else
			int count = 0;
			while (x) 
			{
				x &= (x - 1);
				++count;
			}
			return count;
#endif
		}

		static BASISU_FORCE_INLINE int fast_roundf_int(float x)
		{
			return (x >= 0.0f) ? (int)(x + 0.5f) : (int)(x - 0.5f);
		}
												
		static void fast_encode_bc6h_2subsets_pattern(
			uint32_t best_pat_index, uint32_t best_pat_bits,
			const basist::half_float* pPixels, const vec3F* pFloat_pixels, const float* pPixel_scales,
			double& cur_error, basist::bc6h_logical_block& log_blk,
			int64_t block_max_var,
			int mean_r, int mean_g, int mean_b, 
			const fast_bc6h_params& params)
		{
			BASISU_NOTE_UNUSED(block_max_var);
						
			uint32_t subset_means[2][3] = { { 0 } };
			for (uint32_t i = 0; i < 16; i++)
			{
				const uint32_t subset_index = (best_pat_bits >> i) & 1;
				const uint32_t r = pPixels[i * 3 + 0], g = pPixels[i * 3 + 1], b = pPixels[i * 3 + 2];
				
				subset_means[subset_index][0] += r;
				subset_means[subset_index][1] += g;
				subset_means[subset_index][2] += b;
			}

			for (uint32_t s = 0; s < 2; s++)
				for (uint32_t c = 0; c < 3; c++)
					subset_means[s][c] = (subset_means[s][c] + 8) / 16;

			int64_t subset_icov[2][6] = { { 0 } };

			for (uint32_t i = 0; i < 16; i++)
			{
				const uint32_t subset_index = (best_pat_bits >> i) & 1;
				const int r = (int)pPixels[i * 3 + 0] - mean_r, g = (int)pPixels[i * 3 + 1] - mean_g, b = (int)pPixels[i * 3 + 2] - mean_b;

				subset_icov[subset_index][0] += r * r;
				subset_icov[subset_index][1] += r * g;
				subset_icov[subset_index][2] += r * b;
				subset_icov[subset_index][3] += g * g;
				subset_icov[subset_index][4] += g * b;
				subset_icov[subset_index][5] += b * b;
			}

			vec3F subset_axis[2];

			for (uint32_t subset_index = 0; subset_index < 2; subset_index++)
			{
				float cov[6];
				for (uint32_t i = 0; i < 6; i++)
					cov[i] = (float)subset_icov[subset_index][i];

				const float sc = 1.0f / (basisu::maximum(cov[0], cov[3], cov[5]) + basisu::REALLY_SMALL_FLOAT_VAL);
				const float wx = sc * cov[0], wy = sc * cov[3], wz = sc * cov[5];

				const float alt_xr = cov[0] * wx + cov[1] * wy + cov[2] * wz;
				const float alt_xg = cov[1] * wx + cov[3] * wy + cov[4] * wz;
				const float alt_xb = cov[2] * wx + cov[4] * wy + cov[5] * wz;

				float l = basisu::squaref(alt_xr) + basisu::squaref(alt_xg) + basisu::squaref(alt_xb);

				float axis_r = 0.57735027f, axis_g = 0.57735027f, axis_b = 0.57735027f;
				if (fabs(l) >= basisu::SMALL_FLOAT_VAL)
				{
					const float inv_l = inv_sqrt(l);
					axis_r = alt_xr * inv_l;
					axis_g = alt_xg * inv_l;
					axis_b = alt_xb * inv_l;
				}

				subset_axis[subset_index].set(axis_r, axis_g, axis_b);
			} // s
						
			float subset_min_dot[2] = { basisu::BIG_FLOAT_VAL, basisu::BIG_FLOAT_VAL };
			float subset_max_dot[2] = { -basisu::BIG_FLOAT_VAL, -basisu::BIG_FLOAT_VAL };
			int subset_min_idx[2] = { 0 }, subset_max_idx[2] = { 0 };

			for (uint32_t i = 0; i < 16; i++)
			{
				const uint32_t subset_index = (best_pat_bits >> i) & 1;
				const float r = (float)pPixels[i * 3 + 0], g = (float)pPixels[i * 3 + 1], b = (float)pPixels[i * 3 + 2];
				const float dot = r * subset_axis[subset_index].c[0] + g * subset_axis[subset_index].c[1] + b * subset_axis[subset_index].c[2];

				if (dot < subset_min_dot[subset_index])
				{
					subset_min_dot[subset_index] = dot;
					subset_min_idx[subset_index] = i;
				}

				if (dot > subset_max_dot[subset_index])
				{
					subset_max_dot[subset_index] = dot;
					subset_max_idx[subset_index] = i;
				}
			} // i

			uint32_t subset_min_r[2], subset_min_g[2], subset_min_b[2];
			uint32_t subset_max_r[2], subset_max_g[2], subset_max_b[2];

			for (uint32_t subset_index = 0; subset_index < 2; subset_index++)
			{
				const uint32_t min_index = subset_min_idx[subset_index] * 3, max_index = subset_max_idx[subset_index] * 3;

				subset_min_r[subset_index] = pPixels[min_index + 0];
				subset_min_g[subset_index] = pPixels[min_index + 1];
				subset_min_b[subset_index] = pPixels[min_index + 2];

				subset_max_r[subset_index] = pPixels[max_index + 0];
				subset_max_g[subset_index] = pPixels[max_index + 1];
				subset_max_b[subset_index] = pPixels[max_index + 2];

			} // subset_index

			// least squares with unquantized endpoints
			const bool use_ls = true;
			if (use_ls)
			{
				uint8_t trial_weights[16];
				assign_weights3(trial_weights, best_pat_bits, subset_min_r, subset_min_g, subset_min_b, subset_max_r, subset_max_g, subset_max_b, pFloat_pixels);

				float z00[2] = { 0.0f }, z01[2] = { 0.0f }, z10[2] = { 0.0f }, z11[2] = { 0.0f };
				float q00_r[2] = { 0.0f }, q10_r[2] = { 0.0f }, t_r[2] = { 0.0f };
				float q00_g[2] = { 0.0f }, q10_g[2] = { 0.0f }, t_g[2] = { 0.0f };
				float q00_b[2] = { 0.0f }, q10_b[2] = { 0.0f }, t_b[2] = { 0.0f };

				for (uint32_t i = 0; i < 16; i++)
				{
					const uint32_t subset = (best_pat_bits >> i) & 1;

					float r = (float)pPixels[i * 3 + 0];
					float g = (float)pPixels[i * 3 + 1];
					float b = (float)pPixels[i * 3 + 2];

					const uint32_t sel = trial_weights[i];

					z00[subset] += g_bc6h_ls_weights_3[sel][0];
					z10[subset] += g_bc6h_ls_weights_3[sel][1];
					z11[subset] += g_bc6h_ls_weights_3[sel][2];

					float w = g_bc6h_ls_weights_3[sel][3];

					q00_r[subset] += w * r;
					t_r[subset] += r;

					q00_g[subset] += w * g;
					t_g[subset] += g;

					q00_b[subset] += w * b;
					t_b[subset] += b;
				}

				for (uint32_t subset = 0; subset < 2; subset++)
				{
					q10_r[subset] = t_r[subset] - q00_r[subset];
					q10_g[subset] = t_g[subset] - q00_g[subset];
					q10_b[subset] = t_b[subset] - q00_b[subset];

					z01[subset] = z10[subset];

					float det = z00[subset] * z11[subset] - z01[subset] * z10[subset];
					if (fabs(det) >= basisu::SMALL_FLOAT_VAL)
					{
						det = 1.0f / det;

						float iz00 = z11[subset] * det;
						float iz01 = -z01[subset] * det;
						float iz10 = -z10[subset] * det;
						float iz11 = z00[subset] * det;

						subset_max_r[subset] = basisu::clamp<int>(fast_roundf_int(iz00 * q00_r[subset] + iz01 * q10_r[subset]), 0, (int)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);
						subset_min_r[subset] = basisu::clamp<int>(fast_roundf_int(iz10 * q00_r[subset] + iz11 * q10_r[subset]), 0, (int)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);

						subset_max_g[subset] = basisu::clamp<int>(fast_roundf_int(iz00 * q00_g[subset] + iz01 * q10_g[subset]), 0, (int)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);
						subset_min_g[subset] = basisu::clamp<int>(fast_roundf_int(iz10 * q00_g[subset] + iz11 * q10_g[subset]), 0, (int)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);

						subset_max_b[subset] = basisu::clamp<int>(fast_roundf_int(iz00 * q00_b[subset] + iz01 * q10_b[subset]), 0, (int)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);
						subset_min_b[subset] = basisu::clamp<int>(fast_roundf_int(iz10 * q00_b[subset] + iz11 * q10_b[subset]), 0, (int)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);
					}
				} // subset
			}

			const int BC6H_2SUBSET_ABS_ENDPOINT_MODE = 9;

			int bc6h_mode_index = BC6H_2SUBSET_ABS_ENDPOINT_MODE, num_endpoint_bits = 6;
			uint32_t abs_blog_endpoints[3][4];

			if (params.m_num_diff_endpoint_modes_to_try)
			{
				// ordered from largest base bits to least
				static const int s_bc6h_mode_order2[2] = { 5, 1 }; 
				static const int s_bc6h_mode_order4[4] = { 0, 5, 7, 1 };
				static const int s_bc6h_mode_order9[9] = { 2, 3, 4, 0,  5, 6, 7, 8,  1 };

				uint32_t num_endpoint_modes = 2;
				const int* pBC6H_mode_order = s_bc6h_mode_order2;

				if (params.m_num_diff_endpoint_modes_to_try >= 9)
				{
					num_endpoint_modes = 9;
					pBC6H_mode_order = s_bc6h_mode_order9;
				}
				else if (params.m_num_diff_endpoint_modes_to_try >= 4)
				{
					num_endpoint_modes = 4;
					pBC6H_mode_order = s_bc6h_mode_order4;
				}

				// Find the BC6H mode that will conservatively encode our trial endpoints. The mode chosen will handle any endpoint swaps.
				for (uint32_t bc6h_mode_iter = 0; bc6h_mode_iter < num_endpoint_modes; bc6h_mode_iter++)
				{
					const uint32_t mode = pBC6H_mode_order[bc6h_mode_iter];

					const uint32_t num_base_bits = g_bc6h_mode_sig_bits[mode][0];
					const int base_bitmask = (1 << num_base_bits) - 1;
					BASISU_NOTE_UNUSED(base_bitmask);

					const uint32_t num_delta_bits[3] = { g_bc6h_mode_sig_bits[mode][1], g_bc6h_mode_sig_bits[mode][2], g_bc6h_mode_sig_bits[mode][3] };
					const int delta_bitmasks[3] = { (1 << num_delta_bits[0]) - 1, (1 << num_delta_bits[1]) - 1, (1 << num_delta_bits[2]) - 1 };

					for (uint32_t subset_index = 0; subset_index < 2; subset_index++)
					{
						bc6h_quant_endpoints(
							subset_min_r[subset_index], subset_min_g[subset_index], subset_min_b[subset_index], subset_max_r[subset_index], subset_max_g[subset_index], subset_max_b[subset_index],
							abs_blog_endpoints[0][subset_index * 2 + 0], abs_blog_endpoints[1][subset_index * 2 + 0], abs_blog_endpoints[2][subset_index * 2 + 0],
							abs_blog_endpoints[0][subset_index * 2 + 1], abs_blog_endpoints[1][subset_index * 2 + 1], abs_blog_endpoints[2][subset_index * 2 + 1],
							num_base_bits);
					}

					uint32_t c;
					for (c = 0; c < 3; c++)
					{
						// a very conservative check because we don't have the weight indices yet, so we don't know how to swap end point values
						// purposely enforcing a symmetric limit here so we can invert any endpoints later if needed
						const int max_delta = (1 << (num_delta_bits[c] - 1)) - 1;
						const int min_delta = -max_delta;

						int delta0 = (int)abs_blog_endpoints[c][1] - (int)abs_blog_endpoints[c][0];
						if ((delta0 < min_delta) || (delta0 > max_delta))
							break;

						int delta1 = (int)abs_blog_endpoints[c][2] - (int)abs_blog_endpoints[c][0];
						if ((delta1 < min_delta) || (delta1 > max_delta))
							break;

						int delta2 = (int)abs_blog_endpoints[c][3] - (int)abs_blog_endpoints[c][0];
						if ((delta2 < min_delta) || (delta2 > max_delta))
							break;

						// in case the endpoints are swapped
						int delta3 = (int)abs_blog_endpoints[c][2] - (int)abs_blog_endpoints[c][1];
						if ((delta3 < min_delta) || (delta3 > max_delta))
							break;

						int delta4 = (int)abs_blog_endpoints[c][3] - (int)abs_blog_endpoints[c][1];
						if ((delta4 < min_delta) || (delta4 > max_delta))
							break;
					}

					if (c == 3)
					{
						bc6h_mode_index = mode;
						num_endpoint_bits = num_base_bits;
						break;
					}
				}
			}

			if (bc6h_mode_index == BC6H_2SUBSET_ABS_ENDPOINT_MODE)
			{
				for (uint32_t subset_index = 0; subset_index < 2; subset_index++)
				{
					bc6h_quant_endpoints(
						subset_min_r[subset_index], subset_min_g[subset_index], subset_min_b[subset_index], subset_max_r[subset_index], subset_max_g[subset_index], subset_max_b[subset_index],
						abs_blog_endpoints[0][subset_index * 2 + 0], abs_blog_endpoints[1][subset_index * 2 + 0], abs_blog_endpoints[2][subset_index * 2 + 0],
						abs_blog_endpoints[0][subset_index * 2 + 1], abs_blog_endpoints[1][subset_index * 2 + 1], abs_blog_endpoints[2][subset_index * 2 + 1],
						num_endpoint_bits);
				}
			}

			for (uint32_t subset_index = 0; subset_index < 2; subset_index++)
			{
				bc6h_dequant_endpoints(
					abs_blog_endpoints[0][subset_index * 2 + 0], abs_blog_endpoints[1][subset_index * 2 + 0], abs_blog_endpoints[2][subset_index * 2 + 0],
					abs_blog_endpoints[0][subset_index * 2 + 1], abs_blog_endpoints[1][subset_index * 2 + 1], abs_blog_endpoints[2][subset_index * 2 + 1],
					subset_min_r[subset_index], subset_min_g[subset_index], subset_min_b[subset_index],
					subset_max_r[subset_index], subset_max_g[subset_index], subset_max_b[subset_index], num_endpoint_bits);
			}

			uint8_t trial_weights[16];
			double trial_error = assign_weights_error_3(trial_weights, best_pat_bits, subset_min_r, subset_min_g, subset_min_b, subset_max_r, subset_max_g, subset_max_b, pFloat_pixels, pPixel_scales);

			if (trial_error < cur_error)
			{
				basist::bc6h_logical_block trial_log_blk;

				trial_log_blk.m_mode = bc6h_mode_index;
				trial_log_blk.m_partition_pattern = best_pat_index;
				
				memcpy(trial_log_blk.m_endpoints, abs_blog_endpoints, sizeof(trial_log_blk.m_endpoints));
				memcpy(trial_log_blk.m_weights, trial_weights, 16);
							
				if (trial_log_blk.m_weights[0] & 4)
				{
					for (uint32_t c = 0; c < 3; c++)
						std::swap(trial_log_blk.m_endpoints[c][0], trial_log_blk.m_endpoints[c][1]);

					for (uint32_t i = 0; i < 16; i++)
					{
						const uint32_t subset_index = (best_pat_bits >> i) & 1;
						if (subset_index == 0)
							trial_log_blk.m_weights[i] = 7 - trial_log_blk.m_weights[i];
					}
				}

				const uint32_t subset2_anchor_index = g_bc7_table_anchor_index_second_subset[best_pat_index];
				if (trial_log_blk.m_weights[subset2_anchor_index] & 4)
				{
					for (uint32_t c = 0; c < 3; c++)
						std::swap(trial_log_blk.m_endpoints[c][2], trial_log_blk.m_endpoints[c][3]);

					for (uint32_t i = 0; i < 16; i++)
					{
						const uint32_t subset_index = (best_pat_bits >> i) & 1;
						if (subset_index == 1)
							trial_log_blk.m_weights[i] = 7 - trial_log_blk.m_weights[i];
					}
				}
								
				if (bc6h_mode_index != BC6H_2SUBSET_ABS_ENDPOINT_MODE)
				{
					const uint32_t num_delta_bits[3] = { g_bc6h_mode_sig_bits[bc6h_mode_index][1], g_bc6h_mode_sig_bits[bc6h_mode_index][2], g_bc6h_mode_sig_bits[bc6h_mode_index][3] };
					const int delta_bitmasks[3] = { (1 << num_delta_bits[0]) - 1, (1 << num_delta_bits[1]) - 1, (1 << num_delta_bits[2]) - 1 };

					for (uint32_t c = 0; c < 3; c++)
					{
						const int delta0 = (int)trial_log_blk.m_endpoints[c][1] - (int)trial_log_blk.m_endpoints[c][0];
						const int delta1 = (int)trial_log_blk.m_endpoints[c][2] - (int)trial_log_blk.m_endpoints[c][0];
						const int delta2 = (int)trial_log_blk.m_endpoints[c][3] - (int)trial_log_blk.m_endpoints[c][0];

#ifdef _DEBUG
						// sanity check the final endpoints
						const int max_delta = (1 << (num_delta_bits[c] - 1)) - 1;
						const int min_delta = -(max_delta + 1);
						assert((max_delta - min_delta) == delta_bitmasks[c]);

						if ((delta0 < min_delta) || (delta0 > max_delta) || (delta1 < min_delta) || (delta1 > max_delta) || (delta2 < min_delta) || (delta2 > max_delta))
						{
							assert(0);
							break;
						}
#endif

						trial_log_blk.m_endpoints[c][1] = delta0 & delta_bitmasks[c];
						trial_log_blk.m_endpoints[c][2] = delta1 & delta_bitmasks[c];
						trial_log_blk.m_endpoints[c][3] = delta2 & delta_bitmasks[c];

					} // c
				}

				cur_error = trial_error;
				log_blk = trial_log_blk;
			}
		}

		static void fast_encode_bc6h_2subsets(
			const basist::half_float* pPixels, const vec3F* pFloat_pixels, const float* pPixel_scales,
			double& cur_error, basist::bc6h_logical_block& log_blk,
			int64_t block_max_var,
			int mean_r, int mean_g, int mean_b, float block_axis_r, float block_axis_g, float block_axis_b, 
			const fast_bc6h_params& params)
		{
			assert((params.m_max_2subset_pats_to_try > 0) && (params.m_max_2subset_pats_to_try <= BC6H_NUM_PATS));

			if (params.m_max_2subset_pats_to_try == BC6H_NUM_PATS)
			{
				for (uint32_t i = 0; i < BC6H_NUM_PATS; i++)
				{
					const uint32_t best_pat_index = i;
					const uint32_t best_pat_bits = g_bc6h_pats2[best_pat_index];

					fast_encode_bc6h_2subsets_pattern(
						best_pat_index, best_pat_bits,
						pPixels, pFloat_pixels, pPixel_scales,
						cur_error, log_blk,
						block_max_var,
						mean_r, mean_g, mean_b, params);
				}
				return;
			}
			
			uint32_t desired_pat_bits = 0;
			for (uint32_t i = 0; i < 16; i++)
			{
				float f = (float)(pPixels[i * 3 + 0] - mean_r) * block_axis_r +
					(float)(pPixels[i * 3 + 1] - mean_g) * block_axis_g +
					(float)(pPixels[i * 3 + 2] - mean_b) * block_axis_b;

				desired_pat_bits |= (((f >= 0.0f) ? 1 : 0) << i);
			} // i

			if (params.m_max_2subset_pats_to_try == 1)
			{
				uint32_t best_diff = UINT32_MAX;
				for (uint32_t p = 0; p < BC6H_NUM_PATS; p++)
				{
					const uint32_t bc6h_pat_bits = g_bc6h_pats2[p];

					int diff = popcount32(bc6h_pat_bits ^ desired_pat_bits);
					int diff_inv = 16 - diff;

					uint32_t min_diff = (basisu::minimum<int>(diff, diff_inv) << 8) | p;
					if (min_diff < best_diff)
						best_diff = min_diff;
				} // p

				const uint32_t best_pat_index = best_diff & 0xFF;
				const uint32_t best_pat_bits = g_bc6h_pats2[best_pat_index];

				fast_encode_bc6h_2subsets_pattern(
					best_pat_index, best_pat_bits,
					pPixels, pFloat_pixels, pPixel_scales,
					cur_error, log_blk,
					block_max_var,
					mean_r, mean_g, mean_b, params);
			}
			else
			{
				assert(params.m_max_2subset_pats_to_try <= BC6H_NUM_PATS);
				uint32_t pat_diffs[BC6H_NUM_PATS];

				for (uint32_t p = 0; p < BC6H_NUM_PATS; p++)
				{
					const uint32_t bc6h_pat_bits = g_bc6h_pats2[p];

					int diff = popcount32(bc6h_pat_bits ^ desired_pat_bits);
					int diff_inv = 16 - diff;

					pat_diffs[p] = (basisu::minimum<int>(diff, diff_inv) << 8) | p;
				} // p

				std::sort(pat_diffs, pat_diffs + BC6H_NUM_PATS);

				for (uint32_t pat_iter = 0; pat_iter < params.m_max_2subset_pats_to_try; pat_iter++)
				{
					const uint32_t best_pat_index = pat_diffs[pat_iter] & 0xFF;
					const uint32_t best_pat_bits = g_bc6h_pats2[best_pat_index];

					fast_encode_bc6h_2subsets_pattern(
						best_pat_index, best_pat_bits,
						pPixels, pFloat_pixels, pPixel_scales,
						cur_error, log_blk,
						block_max_var,
						mean_r, mean_g, mean_b, params);
				}
			}
		}

		void fast_encode_bc6h(const basist::half_float* pPixels, basist::bc6h_block* pBlock, const fast_bc6h_params &params)
		{
			basist::bc6h_logical_block log_blk;
			log_blk.clear();

			log_blk.m_mode = basist::BC6H_FIRST_1SUBSET_MODE_INDEX;

			uint32_t omin_r = UINT32_MAX, omin_g = UINT32_MAX, omin_b = UINT32_MAX;
			uint32_t omax_r = 0, omax_g = 0, omax_b = 0;
			uint32_t total_r = 0, total_g = 0, total_b = 0;
						
			for (uint32_t i = 0; i < 16; i++)
			{
				uint32_t r = pPixels[i * 3 + 0];
				uint32_t g = pPixels[i * 3 + 1];
				uint32_t b = pPixels[i * 3 + 2];
								
				total_r += r;
				total_g += g;
				total_b += b;

				omin_r = basisu::minimum(omin_r, r);
				omin_g = basisu::minimum(omin_g, g);
				omin_b = basisu::minimum(omin_b, b);

				omax_r = basisu::maximum(omax_r, r);
				omax_g = basisu::maximum(omax_g, g);
				omax_b = basisu::maximum(omax_b, b);
			}

			if ((omin_r == omax_r) && (omin_g == omax_g) && (omin_b == omax_b))
			{
				// Solid block
				log_blk.m_endpoints[0][0] = basist::bc6h_half_to_blog16((basist::half_float)omin_r);
				log_blk.m_endpoints[0][1] = 0;

				log_blk.m_endpoints[1][0] = basist::bc6h_half_to_blog16((basist::half_float)omin_g);
				log_blk.m_endpoints[1][1] = 0;

				log_blk.m_endpoints[2][0] = basist::bc6h_half_to_blog16((basist::half_float)omin_b);
				log_blk.m_endpoints[2][1] = 0;
				
				log_blk.m_mode = 13;
				pack_bc6h_block(*pBlock, log_blk);

				return;
			}
			
			uint32_t min_r, min_g, min_b, max_r, max_g, max_b;

			int mean_r = (total_r + 8) / 16;
			int mean_g = (total_g + 8) / 16;
			int mean_b = (total_b + 8) / 16;

			int64_t icov[6] = { 0, 0, 0, 0, 0, 0 };

			for (uint32_t i = 0; i < 16; i++)
			{
				int r = (int)pPixels[i * 3 + 0] - mean_r;
				int g = (int)pPixels[i * 3 + 1] - mean_g;
				int b = (int)pPixels[i * 3 + 2] - mean_b;

				icov[0] += r * r;
				icov[1] += r * g;
				icov[2] += r * b;
				icov[3] += g * g;
				icov[4] += g * b;
				icov[5] += b * b;
			}
						
			int64_t block_max_var = basisu::maximum(icov[0], icov[3], icov[5]); // not divided by 16, i.e. scaled by 16
			
			if (block_max_var < (FAST_BC6H_STD_DEV_THRESH * FAST_BC6H_STD_DEV_THRESH * 16))
			{
				// Simple block
				min_r = (omax_r - omin_r) / 32 + omin_r;
				min_g = (omax_g - omin_g) / 32 + omin_g;
				min_b = (omax_b - omin_b) / 32 + omin_b;

				max_r = ((omax_r - omin_r) * 31) / 32 + omin_r;
				max_g = ((omax_g - omin_g) * 31) / 32 + omin_g;
				max_b = ((omax_b - omin_b) * 31) / 32 + omin_b;

				assert((max_r < MAX_HALF_FLOAT_AS_INT_BITS) && (max_g < MAX_HALF_FLOAT_AS_INT_BITS) && (max_b < MAX_HALF_FLOAT_AS_INT_BITS));

				bc6h_quant_dequant_endpoints(min_r, min_g, min_b, max_r, max_g, max_b, 10);

				assign_weights_simple_4(pPixels, log_blk.m_weights, min_r, min_g, min_b, max_r, max_g, max_b, block_max_var);

				log_blk.m_endpoints[0][0] = basist::bc6h_half_to_blog((basist::half_float)min_r, 10);
				log_blk.m_endpoints[0][1] = basist::bc6h_half_to_blog((basist::half_float)max_r, 10);

				log_blk.m_endpoints[1][0] = basist::bc6h_half_to_blog((basist::half_float)min_g, 10);
				log_blk.m_endpoints[1][1] = basist::bc6h_half_to_blog((basist::half_float)max_g, 10);

				log_blk.m_endpoints[2][0] = basist::bc6h_half_to_blog((basist::half_float)min_b, 10);
				log_blk.m_endpoints[2][1] = basist::bc6h_half_to_blog((basist::half_float)max_b, 10);

				if (log_blk.m_weights[0] & 8)
				{
					for (uint32_t i = 0; i < 16; i++)
						log_blk.m_weights[i] = 15 - log_blk.m_weights[i];

					for (uint32_t c = 0; c < 3; c++)
					{
						std::swap(log_blk.m_endpoints[c][0], log_blk.m_endpoints[c][1]);
					}
				}

				pack_bc6h_block(*pBlock, log_blk);

				return;
			}

			// block_max_var cannot be 0 here, also trace cannot be 0

			// Complex block (edges/strong gradients)
			bool try_2subsets = false;
			double cur_err = 0.0f;
			vec3F float_pixels[16];
			float pixel_scales[16];

			// covar rows are:
			// 0, 1, 2
			// 1, 3, 4
			// 2, 4, 5
			float cov[6];
			for (uint32_t i = 0; i < 6; i++)
				cov[i] = (float)icov[i];

			const float sc = 1.0f / (float)block_max_var;
			const float wx = sc * cov[0], wy = sc * cov[3], wz = sc * cov[5];

			const float alt_xr = cov[0] * wx + cov[1] * wy + cov[2] * wz;
			const float alt_xg = cov[1] * wx + cov[3] * wy + cov[4] * wz;
			const float alt_xb = cov[2] * wx + cov[4] * wy + cov[5] * wz;

			float l = basisu::squaref(alt_xr) + basisu::squaref(alt_xg) + basisu::squaref(alt_xb);

			float axis_r = 0.57735027f, axis_g = 0.57735027f, axis_b = 0.57735027f;
			if (fabs(l) >= basisu::SMALL_FLOAT_VAL)
			{
				const float inv_l = inv_sqrt(l);
				axis_r = alt_xr * inv_l;
				axis_g = alt_xg * inv_l;
				axis_b = alt_xb * inv_l;
			}

			const float tr = axis_r * cov[0] + axis_g * cov[1] + axis_b * cov[2];
			const float tg = axis_r * cov[1] + axis_g * cov[3] + axis_b * cov[4];
			const float tb = axis_r * cov[2] + axis_g * cov[4] + axis_b * cov[5];
			const float principle_axis_var = tr * axis_r + tg * axis_g + tb * axis_b;

			const float inv_principle_axis_var = 1.0f / (principle_axis_var + basisu::REALLY_SMALL_FLOAT_VAL);
			axis_r = tr * inv_principle_axis_var;
			axis_g = tg * inv_principle_axis_var;
			axis_b = tb * inv_principle_axis_var;

			float total_var = cov[0] + cov[3] + cov[5];

			// If the principle axis variance vs. the block's total variance accounts for less than this threshold, it's a "very complex" block that may benefit from 2 subsets.
			const float COMPLEX_BLOCK_PRINCIPLE_AXIS_FRACT_THRESH = .995f;
			try_2subsets = principle_axis_var < (total_var * COMPLEX_BLOCK_PRINCIPLE_AXIS_FRACT_THRESH);

			uint32_t min_idx = 0, max_idx = 0;
			float min_dot = basisu::BIG_FLOAT_VAL, max_dot = -basisu::BIG_FLOAT_VAL;
								
			for (uint32_t i = 0; i < 16; i++)
			{
				float r = (float)pPixels[i * 3 + 0];
				float g = (float)pPixels[i * 3 + 1];
				float b = (float)pPixels[i * 3 + 2];

				float_pixels[i].c[0] = fast_half_to_float_pos_not_inf_or_nan((half_float)r);
				float_pixels[i].c[1] = fast_half_to_float_pos_not_inf_or_nan((half_float)g);
				float_pixels[i].c[2] = fast_half_to_float_pos_not_inf_or_nan((half_float)b);

				pixel_scales[i] = 1.0f / (basisu::squaref(float_pixels[i].c[0]) + basisu::squaref(float_pixels[i].c[1]) + basisu::squaref(float_pixels[i].c[2]) + (float)MIN_HALF_FLOAT);

				float dot = r * axis_r + g * axis_g + b * axis_b;

				if (dot < min_dot)
				{
					min_dot = dot;
					min_idx = i;
				}

				if (dot > max_dot)
				{
					max_dot = dot;
					max_idx = i;
				}
			}

			min_r = pPixels[min_idx * 3 + 0];
			min_g = pPixels[min_idx * 3 + 1];
			min_b = pPixels[min_idx * 3 + 2];

			max_r = pPixels[max_idx * 3 + 0];
			max_g = pPixels[max_idx * 3 + 1];
			max_b = pPixels[max_idx * 3 + 2];

			assert((max_r < MAX_HALF_FLOAT_AS_INT_BITS) && (max_g < MAX_HALF_FLOAT_AS_INT_BITS) && (max_b < MAX_HALF_FLOAT_AS_INT_BITS));

			bc6h_quant_dequant_endpoints(min_r, min_g, min_b, max_r, max_g, max_b, 10);

			cur_err = assign_weights_4(float_pixels, pixel_scales, log_blk.m_weights, min_r, min_g, min_b, max_r, max_g, max_b, block_max_var, try_2subsets, params);
						
			const uint32_t MAX_LS_PASSES = params.m_hq_ls ? 2 : 1;
			for (uint32_t pass = 0; pass < MAX_LS_PASSES; pass++)
			{
				float z00 = 0.0f, z01 = 0.0f, z10 = 0.0f, z11 = 0.0f;
				float q00_r = 0.0f, q10_r = 0.0f, t_r = 0.0f;
				float q00_g = 0.0f, q10_g = 0.0f, t_g = 0.0f;
				float q00_b = 0.0f, q10_b = 0.0f, t_b = 0.0f;

				for (uint32_t i = 0; i < 16; i++)
				{
					float r = (float)pPixels[i * 3 + 0];
					float g = (float)pPixels[i * 3 + 1];
					float b = (float)pPixels[i * 3 + 2];

					const uint32_t sel = log_blk.m_weights[i];

					z00 += g_bc6h_ls_weights_4[sel][0];
					z10 += g_bc6h_ls_weights_4[sel][1];
					z11 += g_bc6h_ls_weights_4[sel][2];

					float w = g_bc6h_ls_weights_4[sel][3];

					q00_r += w * r;
					t_r += r;

					q00_g += w * g;
					t_g += g;

					q00_b += w * b;
					t_b += b;
				}

				q10_r = t_r - q00_r;
				q10_g = t_g - q00_g;
				q10_b = t_b - q00_b;

				z01 = z10;

				float det = z00 * z11 - z01 * z10;
				if (fabs(det) < basisu::SMALL_FLOAT_VAL)
					break;

				det = 1.0f / det;

				float iz00 = z11 * det;
				float iz01 = -z01 * det;
				float iz10 = -z10 * det;
				float iz11 = z00 * det;

				uint32_t trial_max_r = (int)basisu::clamp<float>(std::round(iz00 * q00_r + iz01 * q10_r), 0, (float)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);
				uint32_t trial_min_r = (int)basisu::clamp<float>(std::round(iz10 * q00_r + iz11 * q10_r), 0, (float)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);

				uint32_t trial_max_g = (int)basisu::clamp<float>(std::round(iz00 * q00_g + iz01 * q10_g), 0, (float)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);
				uint32_t trial_min_g = (int)basisu::clamp<float>(std::round(iz10 * q00_g + iz11 * q10_g), 0, (float)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);

				uint32_t trial_max_b = (int)basisu::clamp<float>(std::round(iz00 * q00_b + iz01 * q10_b), 0, (float)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);
				uint32_t trial_min_b = (int)basisu::clamp<float>(std::round(iz10 * q00_b + iz11 * q10_b), 0, (float)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);

				bc6h_quant_dequant_endpoints(trial_min_r, trial_min_g, trial_min_b, trial_max_r, trial_max_g, trial_max_b, 10);

				uint8_t trial_weights[16];
				double trial_err = assign_weights_4(float_pixels, pixel_scales, trial_weights, trial_min_r, trial_min_g, trial_min_b, trial_max_r, trial_max_g, trial_max_b, block_max_var, try_2subsets, params);

				if (trial_err < cur_err)
				{
					cur_err = trial_err;

					min_r = trial_min_r;
					max_r = trial_max_r;

					min_g = trial_min_g;
					max_g = trial_max_g;

					min_b = trial_min_b;
					max_b = trial_max_b;
												
					memcpy(log_blk.m_weights, trial_weights, 16);
				}
				else
				{
					break;
				}

			} // pass

#if 0
			//if (full_flag)
			if ((try_2subsets) && (block_max_var > (FAST_BC6H_COMPLEX_STD_DEV_THRESH * FAST_BC6H_COMPLEX_STD_DEV_THRESH * 16)))
			{
				min_r = 0;
				max_r = 0;
				min_g = 0;
				max_g = 0;
				min_b = 0;
				max_b = 0;
			}
#endif

			log_blk.m_endpoints[0][0] = basist::bc6h_half_to_blog((basist::half_float)min_r, 10);
			log_blk.m_endpoints[0][1] = basist::bc6h_half_to_blog((basist::half_float)max_r, 10);

			log_blk.m_endpoints[1][0] = basist::bc6h_half_to_blog((basist::half_float)min_g, 10);
			log_blk.m_endpoints[1][1] = basist::bc6h_half_to_blog((basist::half_float)max_g, 10);

			log_blk.m_endpoints[2][0] = basist::bc6h_half_to_blog((basist::half_float)min_b, 10);
			log_blk.m_endpoints[2][1] = basist::bc6h_half_to_blog((basist::half_float)max_b, 10);

			if (log_blk.m_weights[0] & 8)
			{
				for (uint32_t i = 0; i < 16; i++)
					log_blk.m_weights[i] = 15 - log_blk.m_weights[i];

				for (uint32_t c = 0; c < 3; c++)
				{
					std::swap(log_blk.m_endpoints[c][0], log_blk.m_endpoints[c][1]);
				}
			}
			
			if ((params.m_max_2subset_pats_to_try > 0) && ((try_2subsets) && (block_max_var > (FAST_BC6H_COMPLEX_STD_DEV_THRESH * FAST_BC6H_COMPLEX_STD_DEV_THRESH * 16))))
			{
				fast_encode_bc6h_2subsets(pPixels, float_pixels, pixel_scales, cur_err, log_blk, block_max_var, mean_r, mean_g, mean_b, axis_r, axis_g, axis_b, params);
			}

			pack_bc6h_block(*pBlock, log_blk);
		}

		bool decode_6x6_hdr(const uint8_t *pComp_data, uint32_t comp_data_size, basisu::vector2D<astc_helpers::astc_block>& decoded_blocks, uint32_t& width, uint32_t& height)
		{
			const uint32_t BLOCK_W = 6, BLOCK_H = 6;

			//interval_timer tm;
			//tm.start();

			width = 0;
			height = 0;

			if (comp_data_size <= (2 * 3 + 1))
				return false;

			basist::bitwise_decoder decoder;
			if (!decoder.init(pComp_data, comp_data_size))
				return false;

			if (decoder.get_bits(16) != 0xABCD)
				return false;

			width = decoder.get_bits(16);
			height = decoder.get_bits(16);

			if (!width || !height || (width > MAX_ASTC_HDR_6X6_DIM) || (height > MAX_ASTC_HDR_6X6_DIM))
				return false;

			const uint32_t num_blocks_x = (width + BLOCK_W - 1) / BLOCK_W;
			const uint32_t num_blocks_y = (height + BLOCK_H - 1) / BLOCK_H;

			const uint32_t total_blocks = num_blocks_x * num_blocks_y;

			decoded_blocks.resize(num_blocks_x, num_blocks_y);
			//memset(decoded_blocks.get_ptr(), 0, decoded_blocks.size_in_bytes());

			// These are the decoded log blocks, NOT the output log blocks.
			basisu::vector2D<astc_helpers::log_astc_block> decoded_log_blocks(num_blocks_x, REUSE_MAX_BUFFER_ROWS);
			memset(decoded_log_blocks.get_ptr(), 0, decoded_log_blocks.size_in_bytes());

			uint32_t cur_bx = 0, cur_by = 0;
			int cur_row_index = 0;

			uint32_t step_counter = 0;
			BASISU_NOTE_UNUSED(step_counter);

			while (cur_by < num_blocks_y)
			{
				step_counter++;

				//if ((cur_bx == 9) && (cur_by == 13))
				//	printf("!");

#if SYNC_MARKERS
				uint32_t mk = decoder.get_bits(16);
				if (mk != 0xDEAD)
				{
					printf("!");
					assert(0);
					return false;
				}
#endif
				if (decoder.get_bits_remaining() < 1)
					return false;

				encoding_type et = encoding_type::cBlock;

				uint32_t b0 = decoder.get_bits(1);
				if (!b0)
				{
					uint32_t b1 = decoder.get_bits(1);
					if (b1)
						et = encoding_type::cReuse;
					else
					{
						uint32_t b2 = decoder.get_bits(1);
						if (b2)
							et = encoding_type::cSolid;
						else
							et = encoding_type::cRun;
					}
				}

				switch (et)
				{
				case encoding_type::cRun:
				{
					if (!cur_bx && !cur_by)
						return false;

					const uint32_t run_len = decoder.decode_vlc(5) + 1;

					uint32_t num_blocks_remaining = total_blocks - (cur_bx + cur_by * num_blocks_x);
					if (run_len > num_blocks_remaining)
						return false;

					uint32_t prev_bx = cur_bx, prev_by = cur_by;

					if (cur_bx)
						prev_bx--;
					else
					{
						prev_bx = num_blocks_x - 1;
						prev_by--;
					}

					const astc_helpers::log_astc_block& prev_log_blk = decoded_log_blocks(prev_bx, calc_row_index(cur_by, prev_by, cur_row_index));
					const astc_helpers::astc_block& prev_phys_blk = decoded_blocks(prev_bx, prev_by);

					assert((prev_log_blk.m_user_mode == 255) || (prev_log_blk.m_user_mode < TOTAL_BLOCK_MODE_DECS));

					for (uint32_t i = 0; i < run_len; i++)
					{
						decoded_log_blocks(cur_bx, calc_row_index(cur_by, cur_by, cur_row_index)) = prev_log_blk;
						decoded_blocks(cur_bx, cur_by) = prev_phys_blk;

						cur_bx++;
						if (cur_bx == num_blocks_x)
						{
							cur_bx = 0;
							cur_by++;
							cur_row_index = (cur_row_index + 1) % REUSE_MAX_BUFFER_ROWS;
						}
					}

					break;
				}
				case encoding_type::cSolid:
				{
					const basist::half_float rh = (basist::half_float)decoder.get_bits(15);
					const basist::half_float gh = (basist::half_float)decoder.get_bits(15);
					const basist::half_float bh = (basist::half_float)decoder.get_bits(15);

					astc_helpers::log_astc_block& log_blk = decoded_log_blocks(cur_bx, calc_row_index(cur_by, cur_by, cur_row_index));

					log_blk.clear();
					log_blk.m_user_mode = 255;
					log_blk.m_solid_color_flag_hdr = true;
					log_blk.m_solid_color[0] = rh;
					log_blk.m_solid_color[1] = gh;
					log_blk.m_solid_color[2] = bh;
					log_blk.m_solid_color[3] = basist::float_to_half(1.0f);

					bool status = astc_helpers::pack_astc_block(decoded_blocks(cur_bx, cur_by), log_blk);
					if (!status)
						return false;

					cur_bx++;
					if (cur_bx == num_blocks_x)
					{
						cur_bx = 0;
						cur_by++;
						cur_row_index = (cur_row_index + 1) % REUSE_MAX_BUFFER_ROWS;
					}

					break;
				}
				case encoding_type::cReuse:
				{
					if (!cur_bx && !cur_by)
						return false;

					const uint32_t reuse_delta_index = decoder.get_bits(REUSE_XY_DELTA_BITS);

					const int reuse_delta_x = g_reuse_xy_deltas[reuse_delta_index].m_x;
					const int reuse_delta_y = g_reuse_xy_deltas[reuse_delta_index].m_y;

					const int prev_bx = cur_bx + reuse_delta_x, prev_by = cur_by + reuse_delta_y;
					if ((prev_bx < 0) || (prev_bx >= (int)num_blocks_x))
						return false;
					if (prev_by < 0)
						return false;

					const astc_helpers::log_astc_block& prev_log_blk = decoded_log_blocks(prev_bx, calc_row_index(cur_by, prev_by, cur_row_index));

					if (prev_log_blk.m_solid_color_flag_hdr)
						return false;
					assert(prev_log_blk.m_user_mode < TOTAL_BLOCK_MODE_DECS);

					astc_helpers::log_astc_block& log_blk = decoded_log_blocks(cur_bx, calc_row_index(cur_by, cur_by, cur_row_index));
					astc_helpers::astc_block& phys_blk = decoded_blocks(cur_bx, cur_by);

					log_blk = prev_log_blk;

					const uint32_t total_grid_weights = log_blk.m_grid_width * log_blk.m_grid_height * (log_blk.m_dual_plane ? 2 : 1);

					bool status = decode_values(decoder, total_grid_weights, log_blk.m_weight_ise_range, log_blk.m_weights);
					if (!status)
						return false;

#if 0
					const astc_helpers::astc_block& prev_phys_blk = decoded_blocks(prev_bx, prev_by);

					astc_helpers::log_astc_block decomp_blk;
					status = astc_helpers::unpack_block(&prev_phys_blk, decomp_blk, BLOCK_W, BLOCK_H);
					if (!status)
						return false;

					uint8_t transcode_weights[MAX_BLOCK_W * MAX_BLOCK_H * 2];
					requantize_astc_weights(total_grid_weights, log_blk.m_weights, log_blk.m_weight_ise_range, transcode_weights, decomp_blk.m_weight_ise_range);

					copy_weight_grid(log_blk.m_dual_plane, log_blk.m_grid_width, log_blk.m_grid_height, transcode_weights, decomp_blk);
#else
					assert(log_blk.m_user_mode < TOTAL_BLOCK_MODE_DECS);
					const block_mode_desc& bmd = g_block_mode_descs[(uint32_t)log_blk.m_user_mode];
					const uint32_t num_endpoint_values = get_num_endpoint_vals(bmd.m_cem);

					assert(bmd.m_grid_x == log_blk.m_grid_width && bmd.m_grid_y == log_blk.m_grid_height);
					assert(bmd.m_dp == log_blk.m_dual_plane);
					assert(bmd.m_cem == log_blk.m_color_endpoint_modes[0]);
					assert(bmd.m_num_partitions == log_blk.m_num_partitions);
					assert(bmd.m_dp_channel == log_blk.m_color_component_selector);

					// important: bmd.m_weight_ise_range/m_endpoint_ise_range may not match the logical block's due to deltas.

					astc_helpers::log_astc_block decomp_blk;
					decomp_blk.clear();
					decomp_blk.m_dual_plane = bmd.m_dp;
					decomp_blk.m_color_component_selector = (uint8_t)bmd.m_dp_channel;
					decomp_blk.m_partition_id = log_blk.m_partition_id;

					decomp_blk.m_num_partitions = (uint8_t)bmd.m_num_partitions;

					for (uint32_t p = 0; p < bmd.m_num_partitions; p++)
						decomp_blk.m_color_endpoint_modes[p] = (uint8_t)bmd.m_cem;

					decomp_blk.m_endpoint_ise_range = (uint8_t)bmd.m_transcode_endpoint_ise_range;
					decomp_blk.m_weight_ise_range = (uint8_t)bmd.m_transcode_weight_ise_range;

					for (uint32_t p = 0; p < bmd.m_num_partitions; p++)
						requantize_ise_endpoints(bmd.m_cem, log_blk.m_endpoint_ise_range, log_blk.m_endpoints + num_endpoint_values * p, bmd.m_transcode_endpoint_ise_range, decomp_blk.m_endpoints + num_endpoint_values * p);

					uint8_t transcode_weights[BLOCK_W * BLOCK_H * 2];
					requantize_astc_weights(total_grid_weights, log_blk.m_weights, log_blk.m_weight_ise_range, transcode_weights, bmd.m_transcode_weight_ise_range);

					copy_weight_grid(bmd.m_dp, bmd.m_grid_x, bmd.m_grid_y, transcode_weights, decomp_blk);
#endif
					status = astc_helpers::pack_astc_block(phys_blk, decomp_blk);
					if (!status)
						return false;

					cur_bx++;
					if (cur_bx == num_blocks_x)
					{
						cur_bx = 0;
						cur_by++;
						cur_row_index = (cur_row_index + 1) % REUSE_MAX_BUFFER_ROWS;
					}

					break;
				}
				case encoding_type::cBlock:
				{
					const block_mode bm = (block_mode)decoder.decode_truncated_binary((uint32_t)block_mode::cBMTotalModes);
					const endpoint_mode em = (endpoint_mode)decoder.decode_truncated_binary((uint32_t)endpoint_mode::cTotal);

					switch (em)
					{
					case endpoint_mode::cUseLeft:
					case endpoint_mode::cUseUpper:
					{
						int neighbor_bx = cur_bx, neighbor_by = cur_by;

						if (em == endpoint_mode::cUseLeft)
							neighbor_bx--;
						else
							neighbor_by--;

						if ((neighbor_bx < 0) || (neighbor_by < 0))
							return false;

						const astc_helpers::log_astc_block& neighbor_blk = decoded_log_blocks(neighbor_bx, calc_row_index(cur_by, neighbor_by, cur_row_index));
						if (!neighbor_blk.m_color_endpoint_modes[0])
							return false;

						const block_mode_desc& bmd = g_block_mode_descs[(uint32_t)bm];
						const uint32_t num_endpoint_values = get_num_endpoint_vals(bmd.m_cem);

						if (bmd.m_cem != neighbor_blk.m_color_endpoint_modes[0])
							return false;

						astc_helpers::log_astc_block& log_blk = decoded_log_blocks(cur_bx, calc_row_index(cur_by, cur_by, cur_row_index));
						astc_helpers::astc_block& phys_blk = decoded_blocks(cur_bx, cur_by);

						log_blk.clear();
						assert((uint32_t)bm <= UINT8_MAX);
						log_blk.m_user_mode = (uint8_t)bm;
						log_blk.m_num_partitions = 1;
						log_blk.m_color_endpoint_modes[0] = (uint8_t)bmd.m_cem;
						// Important: Notice how we're copying the neighbor's endpoint ISE range. Not using the mode's endpoint ISE range here.
						// This is to avoid introducing more quantization error.
						log_blk.m_endpoint_ise_range = neighbor_blk.m_endpoint_ise_range;
						log_blk.m_weight_ise_range = (uint8_t)bmd.m_weight_ise_range;
						log_blk.m_grid_width = (uint8_t)bmd.m_grid_x;
						log_blk.m_grid_height = (uint8_t)bmd.m_grid_y;
						log_blk.m_dual_plane = (uint8_t)bmd.m_dp;
						log_blk.m_color_component_selector = (uint8_t)bmd.m_dp_channel;

						memcpy(log_blk.m_endpoints, neighbor_blk.m_endpoints, num_endpoint_values);

						const uint32_t total_grid_weights = bmd.m_grid_x * bmd.m_grid_y * (bmd.m_dp ? 2 : 1);

						bool status = decode_values(decoder, total_grid_weights, bmd.m_weight_ise_range, log_blk.m_weights);
						if (!status)
							return false;

						astc_helpers::log_astc_block decomp_blk;
						decomp_blk.clear();

						decomp_blk.m_num_partitions = 1;
						decomp_blk.m_color_endpoint_modes[0] = (uint8_t)bmd.m_cem;
						decomp_blk.m_endpoint_ise_range = (uint8_t)bmd.m_transcode_endpoint_ise_range;
						decomp_blk.m_weight_ise_range = (uint8_t)bmd.m_transcode_weight_ise_range;
						decomp_blk.m_dual_plane = (uint8_t)bmd.m_dp;
						decomp_blk.m_color_component_selector = (uint8_t)bmd.m_dp_channel;

						requantize_ise_endpoints(bmd.m_cem, log_blk.m_endpoint_ise_range, log_blk.m_endpoints, bmd.m_transcode_endpoint_ise_range, decomp_blk.m_endpoints);

						uint8_t transcode_weights[BLOCK_W * BLOCK_H * 2];
						requantize_astc_weights(total_grid_weights, log_blk.m_weights, bmd.m_weight_ise_range, transcode_weights, bmd.m_transcode_weight_ise_range);

						copy_weight_grid(bmd.m_dp, bmd.m_grid_x, bmd.m_grid_y, transcode_weights, decomp_blk);

						status = astc_helpers::pack_astc_block(phys_blk, decomp_blk);
						if (!status)
							return false;

						cur_bx++;
						if (cur_bx == num_blocks_x)
						{
							cur_bx = 0;
							cur_by++;
							cur_row_index = (cur_row_index + 1) % REUSE_MAX_BUFFER_ROWS;
						}

						break;
					}
					case endpoint_mode::cUseLeftDelta:
					case endpoint_mode::cUseUpperDelta:
					{
						int neighbor_bx = cur_bx, neighbor_by = cur_by;

						if (em == endpoint_mode::cUseLeftDelta)
							neighbor_bx--;
						else
							neighbor_by--;

						if ((neighbor_bx < 0) || (neighbor_by < 0))
							return false;

						const astc_helpers::log_astc_block& neighbor_blk = decoded_log_blocks(neighbor_bx, calc_row_index(cur_by, neighbor_by, cur_row_index));
						if (!neighbor_blk.m_color_endpoint_modes[0])
							return false;

						const block_mode_desc& bmd = g_block_mode_descs[(uint32_t)bm];
						const uint32_t num_endpoint_values = get_num_endpoint_vals(bmd.m_cem);

						if (bmd.m_cem != neighbor_blk.m_color_endpoint_modes[0])
							return false;

						astc_helpers::log_astc_block& log_blk = decoded_log_blocks(cur_bx, calc_row_index(cur_by, cur_by, cur_row_index));
						astc_helpers::astc_block& phys_blk = decoded_blocks(cur_bx, cur_by);

						log_blk.clear();
						assert((uint32_t)bm <= UINT8_MAX);
						log_blk.m_user_mode = (uint8_t)bm;
						log_blk.m_num_partitions = 1;
						log_blk.m_color_endpoint_modes[0] = (uint8_t)bmd.m_cem;
						log_blk.m_dual_plane = bmd.m_dp;
						log_blk.m_color_component_selector = (uint8_t)bmd.m_dp_channel;

						log_blk.m_endpoint_ise_range = (uint8_t)bmd.m_endpoint_ise_range;
						requantize_ise_endpoints(bmd.m_cem, neighbor_blk.m_endpoint_ise_range, neighbor_blk.m_endpoints, bmd.m_endpoint_ise_range, log_blk.m_endpoints);

						const int total_endpoint_delta_vals = 1 << NUM_ENDPOINT_DELTA_BITS;
						const int low_delta_limit = -(total_endpoint_delta_vals / 2); // high_delta_limit = (total_endpoint_delta_vals / 2) - 1;

						const auto& ise_to_rank = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_ISE_to_rank;
						const auto& rank_to_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_rank_to_ISE;
						const int total_endpoint_levels = astc_helpers::get_ise_levels(log_blk.m_endpoint_ise_range);

						for (uint32_t i = 0; i < num_endpoint_values; i++)
						{
							int cur_val = ise_to_rank[log_blk.m_endpoints[i]];

							int delta = (int)decoder.get_bits(NUM_ENDPOINT_DELTA_BITS) + low_delta_limit;

							cur_val += delta;
							if ((cur_val < 0) || (cur_val >= total_endpoint_levels))
								return false;

							log_blk.m_endpoints[i] = rank_to_ise[cur_val];
						}

						log_blk.m_weight_ise_range = (uint8_t)bmd.m_weight_ise_range;
						log_blk.m_grid_width = (uint8_t)bmd.m_grid_x;
						log_blk.m_grid_height = (uint8_t)bmd.m_grid_y;

						const uint32_t total_grid_weights = bmd.m_grid_x * bmd.m_grid_y * (bmd.m_dp ? 2 : 1);

						bool status = decode_values(decoder, total_grid_weights, bmd.m_weight_ise_range, log_blk.m_weights);
						if (!status)
							return false;

						astc_helpers::log_astc_block decomp_blk;
						decomp_blk.clear();

						decomp_blk.m_num_partitions = 1;
						decomp_blk.m_color_endpoint_modes[0] = (uint8_t)bmd.m_cem;
						decomp_blk.m_endpoint_ise_range = (uint8_t)bmd.m_transcode_endpoint_ise_range;
						decomp_blk.m_weight_ise_range = (uint8_t)bmd.m_transcode_weight_ise_range;
						decomp_blk.m_dual_plane = (uint8_t)bmd.m_dp;
						decomp_blk.m_color_component_selector = (uint8_t)bmd.m_dp_channel;

						requantize_ise_endpoints(bmd.m_cem, log_blk.m_endpoint_ise_range, log_blk.m_endpoints, bmd.m_transcode_endpoint_ise_range, decomp_blk.m_endpoints);

						uint8_t transcode_weights[BLOCK_W * BLOCK_H * 2];
						requantize_astc_weights(total_grid_weights, log_blk.m_weights, bmd.m_weight_ise_range, transcode_weights, bmd.m_transcode_weight_ise_range);

						copy_weight_grid(bmd.m_dp, bmd.m_grid_x, bmd.m_grid_y, transcode_weights, decomp_blk);

						status = astc_helpers::pack_astc_block(phys_blk, decomp_blk);
						if (!status)
							return false;

						cur_bx++;
						if (cur_bx == num_blocks_x)
						{
							cur_bx = 0;
							cur_by++;
							cur_row_index = (cur_row_index + 1) % REUSE_MAX_BUFFER_ROWS;
						}

						break;
					}
					case endpoint_mode::cRaw:
					{
						const block_mode_desc& bmd = g_block_mode_descs[(uint32_t)bm];

						const uint32_t num_endpoint_values = get_num_endpoint_vals(bmd.m_cem);

						astc_helpers::log_astc_block& log_blk = decoded_log_blocks(cur_bx, calc_row_index(cur_by, cur_by, cur_row_index));
						astc_helpers::astc_block& phys_blk = decoded_blocks(cur_bx, cur_by);

						log_blk.clear();

						assert((uint32_t)bm <= UINT8_MAX);
						log_blk.m_user_mode = (uint8_t)bm;

						log_blk.m_num_partitions = (uint8_t)bmd.m_num_partitions;

						for (uint32_t p = 0; p < bmd.m_num_partitions; p++)
							log_blk.m_color_endpoint_modes[p] = (uint8_t)bmd.m_cem;

						log_blk.m_endpoint_ise_range = (uint8_t)bmd.m_endpoint_ise_range;
						log_blk.m_weight_ise_range = (uint8_t)bmd.m_weight_ise_range;

						log_blk.m_grid_width = (uint8_t)bmd.m_grid_x;
						log_blk.m_grid_height = (uint8_t)bmd.m_grid_y;
						log_blk.m_dual_plane = (uint8_t)bmd.m_dp;
						log_blk.m_color_component_selector = (uint8_t)bmd.m_dp_channel;

						if (bmd.m_num_partitions == 2)
						{
							const uint32_t unique_partition_index = decoder.decode_truncated_binary(NUM_UNIQUE_PARTITIONS2);
							log_blk.m_partition_id = (uint16_t)g_part2_unique_index_to_seed[unique_partition_index];
						}
						else if (bmd.m_num_partitions == 3)
						{
							const uint32_t unique_partition_index = decoder.decode_truncated_binary(NUM_UNIQUE_PARTITIONS3);
							log_blk.m_partition_id = (uint16_t)g_part3_unique_index_to_seed[unique_partition_index];
						}

						bool status = decode_values(decoder, num_endpoint_values * bmd.m_num_partitions, bmd.m_endpoint_ise_range, log_blk.m_endpoints);
						if (!status)
							return false;

						const uint32_t total_grid_weights = bmd.m_grid_x * bmd.m_grid_y * (bmd.m_dp ? 2 : 1);

						status = decode_values(decoder, total_grid_weights, bmd.m_weight_ise_range, log_blk.m_weights);
						if (!status)
							return false;

						astc_helpers::log_astc_block decomp_blk;
						decomp_blk.clear();
						decomp_blk.m_dual_plane = bmd.m_dp;
						decomp_blk.m_color_component_selector = (uint8_t)bmd.m_dp_channel;
						decomp_blk.m_partition_id = log_blk.m_partition_id;

						decomp_blk.m_num_partitions = (uint8_t)bmd.m_num_partitions;

						for (uint32_t p = 0; p < bmd.m_num_partitions; p++)
							decomp_blk.m_color_endpoint_modes[p] = (uint8_t)bmd.m_cem;

						decomp_blk.m_endpoint_ise_range = (uint8_t)bmd.m_transcode_endpoint_ise_range;
						decomp_blk.m_weight_ise_range = (uint8_t)bmd.m_transcode_weight_ise_range;

						for (uint32_t p = 0; p < bmd.m_num_partitions; p++)
							requantize_ise_endpoints(bmd.m_cem, bmd.m_endpoint_ise_range, log_blk.m_endpoints + num_endpoint_values * p, bmd.m_transcode_endpoint_ise_range, decomp_blk.m_endpoints + num_endpoint_values * p);

						uint8_t transcode_weights[BLOCK_W * BLOCK_H * 2];
						requantize_astc_weights(total_grid_weights, log_blk.m_weights, bmd.m_weight_ise_range, transcode_weights, bmd.m_transcode_weight_ise_range);

						copy_weight_grid(bmd.m_dp, bmd.m_grid_x, bmd.m_grid_y, transcode_weights, decomp_blk);

						status = astc_helpers::pack_astc_block(phys_blk, decomp_blk);
						if (!status)
							return false;

						cur_bx++;
						if (cur_bx == num_blocks_x)
						{
							cur_bx = 0;
							cur_by++;
							cur_row_index = (cur_row_index + 1) % REUSE_MAX_BUFFER_ROWS;
						}

						break;
					}
					default:
					{
						assert(0);
						return false;
					}
					}

					break;
				}
				default:
				{
					assert(0);
					return false;
				}
				}
			}

			if (decoder.get_bits(16) != 0xA742)
			{
				//fmt_error_printf("End marker not found!\n");
				return false;
			}

			//fmt_printf("Total decode_file() time: {} secs\n", tm.get_elapsed_secs());

			return true;
		}

	} // namespace astc_6x6_hdr

#endif // BASISD_SUPPORT_UASTC_HDR

} // namespace basist