Path: blob/master/BizHawk.Emulation.Cores/Consoles/PC Engine/ADPCM.cs
2 views
using System;
using BizHawk.Common;
using BizHawk.Emulation.Common;
using BizHawk.Emulation.Cores.Components;
namespace BizHawk.Emulation.Cores.PCEngine
{
public sealed class ADPCM : IMixedSoundProvider
{
ScsiCDBus SCSI;
PCEngine pce;
MetaspuSoundProvider SoundProvider = new MetaspuSoundProvider(ESynchMethod.ESynchMethod_V);
// ***************************************************************************
public ushort IOAddress;
public ushort ReadAddress;
public ushort WriteAddress;
public ushort AdpcmLength;
public int ReadTimer, WriteTimer;
public byte ReadBuffer, WriteBuffer;
public bool ReadPending, WritePending;
public byte[] RAM = new byte[0x10000];
// ***************************************************************************
public bool AdpcmIsPlaying;
public bool HalfReached;
public bool EndReached;
public bool AdpcmBusyWriting { get { return AdpcmCdDmaRequested; } }
public bool AdpcmBusyReading { get { return ReadPending; } }
public bool AdpcmCdDmaRequested { get { return (Port180B & 3) != 0; } }
// ***************************************************************************
public byte Port180A
{
set { WritePending = true; WriteTimer = 24; WriteBuffer = value; }
get { ReadPending = true; ReadTimer = 24; return ReadBuffer; }
}
public byte Port180B;
public byte Port180D;
byte port180E;
public byte Port180E
{
get { return port180E; }
set
{
port180E = value;
float khz = 32 / (16 - (Port180E & 0x0F));
destSamplesPerSourceSample = 44.1f / khz;
}
}
// ***************************************************************************
public ADPCM(PCEngine pcEngine, ScsiCDBus scsi)
{
pce = pcEngine;
SCSI = scsi;
MaxVolume = 24576;
}
public void AdpcmControlWrite(byte value)
{
//Log.Error("CD","ADPCM CONTROL WRITE {0:X2}",value);
if ((Port180D & 0x80) != 0 && (value & 0x80) == 0)
{
ReadAddress = 0;
WriteAddress = 0;
IOAddress = 0;
nibble = false;
AdpcmIsPlaying = false;
HalfReached = false;
EndReached = false;
playingSample = 0;
Playback44khzTimer = 0;
magnitude = 0;
}
if ((value & 8) != 0)
{
ReadAddress = IOAddress;
if ((value & 4) == 0)
ReadAddress--;
}
if ((Port180D & 2) == 0 && (value & 2) != 0)
{
WriteAddress = IOAddress;
if ((value & 1) == 0)
WriteAddress--;
}
if ((value & 0x10) != 0)
{
AdpcmLength = IOAddress;
EndReached = false;
}
if (AdpcmIsPlaying && (value & 0x20) == 0)
AdpcmIsPlaying = false; // clearing this bit stops playback
if (AdpcmIsPlaying == false && (value & 0x20) != 0)
{
if ((value & 0x40) == 0)
Console.WriteLine("a thing thats normally set is not set");
AdpcmIsPlaying = true;
playingSample = 2048;
magnitude = 0;
Playback44khzTimer = 0;
}
Port180D = value;
}
public void Think(int cycles)
{
Playback44khzTimer -= cycles;
if (Playback44khzTimer < 0)
{
Playback44khzTimer += 162.81f; // # of CPU cycles that translate to one 44100hz sample.
AdpcmEmitSample();
}
if (ReadTimer > 0) ReadTimer -= cycles;
if (WriteTimer > 0) WriteTimer -= cycles;
if (ReadPending && ReadTimer <= 0)
{
ReadBuffer = RAM[ReadAddress++];
ReadPending = false;
if (AdpcmLength > ushort.MinValue)
AdpcmLength--;
else
{
EndReached = true;
HalfReached = false;
//Port180D &= 0x9F;
}
}
if (WritePending && WriteTimer <= 0)
{
RAM[WriteAddress++] = WriteBuffer;
WritePending = false;
if (AdpcmLength < ushort.MaxValue)
AdpcmLength++;
HalfReached = AdpcmLength < 0x8000;
}
if (AdpcmCdDmaRequested)
{
if (SCSI.REQ && SCSI.IO && !SCSI.CD && !SCSI.ACK)
{
byte dmaByte = SCSI.DataBits;
RAM[WriteAddress++] = dmaByte;
AdpcmLength++;
SCSI.ACK = false;
SCSI.REQ = false;
SCSI.Think();
}
if (SCSI.DataTransferInProgress == false)
Port180B = 0;
}
pce.IntADPCM = HalfReached;
pce.IntStop = EndReached;
pce.RefreshIRQ2();
}
// ***************************************************************************
// Playback Functions
// ***************************************************************************
float Playback44khzTimer;
int playingSample;
float nextSampleTimer;
float destSamplesPerSourceSample;
bool nibble;
int magnitude;
static readonly int[] StepSize =
{
0x0002, 0x0006, 0x000A, 0x000E, 0x0012, 0x0016, 0x001A, 0x001E,
0x0002, 0x0006, 0x000A, 0x000E, 0x0013, 0x0017, 0x001B, 0x001F,
0x0002, 0x0006, 0x000B, 0x000F, 0x0015, 0x0019, 0x001E, 0x0022,
0x0002, 0x0007, 0x000C, 0x0011, 0x0017, 0x001C, 0x0021, 0x0026,
0x0002, 0x0007, 0x000D, 0x0012, 0x0019, 0x001E, 0x0024, 0x0029,
0x0003, 0x0009, 0x000F, 0x0015, 0x001C, 0x0022, 0x0028, 0x002E,
0x0003, 0x000A, 0x0011, 0x0018, 0x001F, 0x0026, 0x002D, 0x0034,
0x0003, 0x000A, 0x0012, 0x0019, 0x0022, 0x0029, 0x0031, 0x0038,
0x0004, 0x000C, 0x0015, 0x001D, 0x0026, 0x002E, 0x0037, 0x003F,
0x0004, 0x000D, 0x0016, 0x001F, 0x0029, 0x0032, 0x003B, 0x0044,
0x0005, 0x000F, 0x0019, 0x0023, 0x002E, 0x0038, 0x0042, 0x004C,
0x0005, 0x0010, 0x001B, 0x0026, 0x0032, 0x003D, 0x0048, 0x0053,
0x0006, 0x0012, 0x001F, 0x002B, 0x0038, 0x0044, 0x0051, 0x005D,
0x0006, 0x0013, 0x0021, 0x002E, 0x003D, 0x004A, 0x0058, 0x0065,
0x0007, 0x0016, 0x0025, 0x0034, 0x0043, 0x0052, 0x0061, 0x0070,
0x0008, 0x0018, 0x0029, 0x0039, 0x004A, 0x005A, 0x006B, 0x007B,
0x0009, 0x001B, 0x002D, 0x003F, 0x0052, 0x0064, 0x0076, 0x0088,
0x000A, 0x001E, 0x0032, 0x0046, 0x005A, 0x006E, 0x0082, 0x0096,
0x000B, 0x0021, 0x0037, 0x004D, 0x0063, 0x0079, 0x008F, 0x00A5,
0x000C, 0x0024, 0x003C, 0x0054, 0x006D, 0x0085, 0x009D, 0x00B5,
0x000D, 0x0027, 0x0042, 0x005C, 0x0078, 0x0092, 0x00AD, 0x00C7,
0x000E, 0x002B, 0x0049, 0x0066, 0x0084, 0x00A1, 0x00BF, 0x00DC,
0x0010, 0x0030, 0x0051, 0x0071, 0x0092, 0x00B2, 0x00D3, 0x00F3,
0x0011, 0x0034, 0x0058, 0x007B, 0x00A0, 0x00C3, 0x00E7, 0x010A,
0x0013, 0x003A, 0x0061, 0x0088, 0x00B0, 0x00D7, 0x00FE, 0x0125,
0x0015, 0x0040, 0x006B, 0x0096, 0x00C2, 0x00ED, 0x0118, 0x0143,
0x0017, 0x0046, 0x0076, 0x00A5, 0x00D5, 0x0104, 0x0134, 0x0163,
0x001A, 0x004E, 0x0082, 0x00B6, 0x00EB, 0x011F, 0x0153, 0x0187,
0x001C, 0x0055, 0x008F, 0x00C8, 0x0102, 0x013B, 0x0175, 0x01AE,
0x001F, 0x005E, 0x009D, 0x00DC, 0x011C, 0x015B, 0x019A, 0x01D9,
0x0022, 0x0067, 0x00AD, 0x00F2, 0x0139, 0x017E, 0x01C4, 0x0209,
0x0026, 0x0072, 0x00BF, 0x010B, 0x0159, 0x01A5, 0x01F2, 0x023E,
0x002A, 0x007E, 0x00D2, 0x0126, 0x017B, 0x01CF, 0x0223, 0x0277,
0x002E, 0x008A, 0x00E7, 0x0143, 0x01A1, 0x01FD, 0x025A, 0x02B6,
0x0033, 0x0099, 0x00FF, 0x0165, 0x01CB, 0x0231, 0x0297, 0x02FD,
0x0038, 0x00A8, 0x0118, 0x0188, 0x01F9, 0x0269, 0x02D9, 0x0349,
0x003D, 0x00B8, 0x0134, 0x01AF, 0x022B, 0x02A6, 0x0322, 0x039D,
0x0044, 0x00CC, 0x0154, 0x01DC, 0x0264, 0x02EC, 0x0374, 0x03FC,
0x004A, 0x00DF, 0x0175, 0x020A, 0x02A0, 0x0335, 0x03CB, 0x0460,
0x0052, 0x00F6, 0x019B, 0x023F, 0x02E4, 0x0388, 0x042D, 0x04D1,
0x005A, 0x010F, 0x01C4, 0x0279, 0x032E, 0x03E3, 0x0498, 0x054D,
0x0063, 0x012A, 0x01F1, 0x02B8, 0x037F, 0x0446, 0x050D, 0x05D4,
0x006D, 0x0148, 0x0223, 0x02FE, 0x03D9, 0x04B4, 0x058F, 0x066A,
0x0078, 0x0168, 0x0259, 0x0349, 0x043B, 0x052B, 0x061C, 0x070C,
0x0084, 0x018D, 0x0296, 0x039F, 0x04A8, 0x05B1, 0x06BA, 0x07C3,
0x0091, 0x01B4, 0x02D8, 0x03FB, 0x051F, 0x0642, 0x0766, 0x0889,
0x00A0, 0x01E0, 0x0321, 0x0461, 0x05A2, 0x06E2, 0x0823, 0x0963,
0x00B0, 0x0210, 0x0371, 0x04D1, 0x0633, 0x0793, 0x08F4, 0x0A54,
0x00C2, 0x0246, 0x03CA, 0x054E, 0x06D2, 0x0856, 0x09DA, 0x0B5E
};
static readonly int[] StepFactor = { -1, -1, -1, -1, 2, 4, 6, 8 };
int AddClamped(int num1, int num2, int min, int max)
{
int result = num1 + num2;
if (result < min) return min;
if (result > max) return max;
return result;
}
byte ReadNibble()
{
byte value;
if (nibble == false)
value = (byte)(RAM[ReadAddress] >> 4);
else
{
value = (byte)(RAM[ReadAddress] & 0xF);
AdpcmLength--;
ReadAddress++;
}
nibble ^= true;
return value;
}
void DecodeAdpcmSample()
{
byte sample = ReadNibble();
bool positive = (sample & 8) == 0;
int mag = sample & 7;
int m = StepFactor[mag];
int adjustment = StepSize[(magnitude * 8) + mag];
magnitude = AddClamped(magnitude, m, 0, 48);
if (positive == false) adjustment *= -1;
playingSample = AddClamped(playingSample, adjustment, 0, 4095);
}
void AdpcmEmitSample()
{
if (AdpcmIsPlaying == false)
SoundProvider.Buffer.enqueue_sample(0, 0);
else
{
if (nextSampleTimer <= 0)
{
DecodeAdpcmSample();
nextSampleTimer += destSamplesPerSourceSample;
}
nextSampleTimer--;
HalfReached = AdpcmLength < 0x8000;
if (AdpcmLength == 0)
{
AdpcmIsPlaying = false;
EndReached = true;
HalfReached = false;
}
short adjustedSample = (short)((playingSample - 2048) * MaxVolume / 2048);
SoundProvider.Buffer.enqueue_sample(adjustedSample, adjustedSample);
}
}
public void GetSamples(short[] samples)
{
SoundProvider.GetSamplesAsync(samples);
}
public void DiscardSamples()
{
SoundProvider.DiscardSamples();
}
public int MaxVolume { get; set; }
// ***************************************************************************
public void SyncState(Serializer ser)
{
ser.BeginSection("ADPCM");
ser.Sync("RAM", ref RAM, false);
ser.Sync("IOAddress", ref IOAddress);
ser.Sync("AdpcmLength", ref AdpcmLength);
ser.Sync("ReadAddress", ref ReadAddress);
ser.Sync("ReadTimer", ref ReadTimer);
ser.Sync("ReadPending", ref ReadPending);
ser.Sync("WriteAddress", ref WriteAddress);
ser.Sync("WriteTimer", ref WriteTimer);
ser.Sync("WriteBuffer", ref WriteBuffer);
ser.Sync("WritePending", ref WritePending);
ser.Sync("Port180B", ref Port180B);
ser.Sync("Port180D", ref Port180D);
ser.Sync("Port180E", ref port180E);
ser.Sync("AdpcmIsPlaying", ref AdpcmIsPlaying);
ser.Sync("HalfReached", ref HalfReached);
ser.Sync("EndReached", ref EndReached);
ser.Sync("Playback44khzTimer", ref Playback44khzTimer);
ser.Sync("PlayingSample", ref playingSample);
ser.Sync("NextSampleTimer", ref nextSampleTimer);
ser.Sync("Nibble", ref nibble);
ser.Sync("Magnitude", ref magnitude);
ser.EndSection();
if (ser.IsReader)
{
Port180E = port180E;
pce.IntADPCM = HalfReached;
pce.IntStop = EndReached;
pce.RefreshIRQ2();
}
}
}
}