CDUtility.h

#ifndef __MDFN_CDROM_CDUTILITY_H
#define __MDFN_CDROM_CDUTILITY_H

namespace CDUtility
{
 // Call once at app startup before creating any threads that could potentially cause re-entrancy to these functions.
 // It will also be called automatically if needed for the first time a function in this namespace that requires
 // the initialization function to be called is called, for potential
 // usage in constructors of statically-declared objects.
 void CDUtility_Init(void);

 // Quick definitions here:
 //
 // ABA - Absolute block address, synonymous to absolute MSF
 //  aba = (m_a * 60 * 75) + (s_a * 75) + f_a
 //
 // LBA - Logical block address(related: data CDs are required to have a pregap of 2 seconds, IE 150 frames/sectors)
 //  lba = aba - 150


 enum
 {
  ADR_NOQINFO = 0x00,
  ADR_CURPOS  = 0x01,
  ADR_MCN     = 0x02,
  ADR_ISRC    = 0x03
 };


 struct TOC_Track
 {
  uint8 adr;
  uint8 control;
  uint32 lba;
  bool valid;	// valid/present; oh CD-i...
 };

 // SubQ control field flags.
 enum
 {
  SUBQ_CTRLF_PRE  = 0x01,	// With 50/15us pre-emphasis.
  SUBQ_CTRLF_DCP  = 0x02,	// Digital copy permitted.
  SUBQ_CTRLF_DATA = 0x04,	// Data track.
  SUBQ_CTRLF_4CH  = 0x08,	// 4-channel CD-DA.
 };

 enum
 {
  DISC_TYPE_CDDA_OR_M1 = 0x00,
  DISC_TYPE_CD_I       = 0x10,
  DISC_TYPE_CD_XA      = 0x20
 };

 struct TOC
 {
  INLINE TOC()
  {
   Clear();
  }

  INLINE void Clear(void)
  {
   first_track = last_track = 0;
   disc_type = 0;

   memset(tracks, 0, sizeof(tracks));	// FIXME if we change TOC_Track to non-POD type.
  }

  INLINE int FindTrackByLBA(uint32 LBA) const
  {
   int32 lvt = 0;

   for(int32 track = 1; track <= 100; track++)
   {
    if(!tracks[track].valid)
     continue;

    if(LBA < tracks[track].lba)
     break;

    lvt = track;
   }

   return(lvt);
  }

  uint8 first_track;
  uint8 last_track;
  uint8 disc_type;
  TOC_Track tracks[100 + 1];  // [0] is unused, [100] is for the leadout track.
 };

 //
 // Address conversion functions.
 //
 static INLINE uint32 AMSF_to_ABA(int32 m_a, int32 s_a, int32 f_a)
 {
  return(f_a + 75 * s_a + 75 * 60 * m_a);
 }

 static INLINE void ABA_to_AMSF(uint32 aba, uint8 *m_a, uint8 *s_a, uint8 *f_a)
 {
  *m_a = aba / 75 / 60;
  *s_a = (aba - *m_a * 75 * 60) / 75;
  *f_a = aba - (*m_a * 75 * 60) - (*s_a * 75);
 }

 static INLINE int32 ABA_to_LBA(uint32 aba)
 {
  return(aba - 150);
 }

 static INLINE uint32 LBA_to_ABA(int32 lba)
 {
  return(lba + 150);
 }

 static INLINE int32 AMSF_to_LBA(uint8 m_a, uint8 s_a, uint8 f_a)
 {
  return(ABA_to_LBA(AMSF_to_ABA(m_a, s_a, f_a)));
 }

 static INLINE void LBA_to_AMSF(int32 lba, uint8 *m_a, uint8 *s_a, uint8 *f_a)
 {
  ABA_to_AMSF(LBA_to_ABA(lba), m_a, s_a, f_a);
 }

 //
 // BCD conversion functions
 //
 static INLINE bool BCD_is_valid(uint8 bcd_number)
 {
  if((bcd_number & 0xF0) >= 0xA0)
   return(false);

  if((bcd_number & 0x0F) >= 0x0A)
   return(false);

  return(true);
 }

 static INLINE uint8 BCD_to_U8(uint8 bcd_number)
 {
  return( ((bcd_number >> 4) * 10) + (bcd_number & 0x0F) );
 }

 static INLINE uint8 U8_to_BCD(uint8 num)
 {
  return( ((num / 10) << 4) + (num % 10) );
 }

 // should always perform the conversion, even if the bcd number is invalid.
 static INLINE bool BCD_to_U8_check(uint8 bcd_number, uint8 *out_number)
 {
  *out_number = BCD_to_U8(bcd_number);

  if(!BCD_is_valid(bcd_number))
   return(false);

  return(true);
 }

 //
 // Sector data encoding functions(to full 2352 bytes raw sector).
 //
 //  sector_data must be able to contain at least 2352 bytes.
 void encode_mode0_sector(uint32 aba, uint8 *sector_data);
 void encode_mode1_sector(uint32 aba, uint8 *sector_data);	// 2048 bytes of user data at offset 16
 void encode_mode2_sector(uint32 aba, uint8 *sector_data);	// 2336 bytes of user data at offset 16 
 void encode_mode2_form1_sector(uint32 aba, uint8 *sector_data);	// 2048+8 bytes of user data at offset 16
 void encode_mode2_form2_sector(uint32 aba, uint8 *sector_data);	// 2324+8 bytes of user data at offset 16


 // User data area pre-pause(MSF 00:00:00 through 00:01:74), lba -150 through -1
 // out_buf must be able to contain 2352+96 bytes.
 // "mode" is not used if the area is to be encoded as audio.
 // pass 0xFF for "mode" for "don't know", and to make guess based on the TOC.
 void synth_udapp_sector_lba(uint8 mode, const TOC& toc, const int32 lba, int32 lba_subq_relative_offs, uint8* out_buf);
 void subpw_synth_udapp_lba(const TOC& toc, const int32 lba, const int32 lba_subq_relative_offs, uint8* SubPWBuf);

 // out_buf must be able to contain 2352+96 bytes.
 // "mode" is not used if the area is to be encoded as audio.
 // pass 0xFF for "mode" for "don't know", and to make guess based on the TOC.
 void synth_leadout_sector_lba(uint8 mode, const TOC& toc, const int32 lba, uint8* out_buf);
 void subpw_synth_leadout_lba(const TOC& toc, const int32 lba, uint8* SubPWBuf);


 //
 // User data error detection and correction
 //

 // Check EDC of a mode 1 or mode 2 form 1 sector.
 //  Returns "true" if checksum is ok(matches).
 //  Returns "false" if checksum mismatch.
 //  sector_data should contain 2352 bytes of raw sector data.
 bool edc_check(const uint8 *sector_data, bool xa);

 // Check EDC and L-EC data of a mode 1 or mode 2 form 1 sector, and correct bit errors if any exist.
 //  Returns "true" if errors weren't detected, or they were corrected succesfully.
 //  Returns "false" if errors couldn't be corrected.
 //  sector_data should contain 2352 bytes of raw sector data.
 bool edc_lec_check_and_correct(uint8 *sector_data, bool xa);

 //
 // Subchannel(Q in particular) functions
 //

 // Returns false on checksum mismatch, true on match.
 bool subq_check_checksum(const uint8 *subq_buf);

 // Calculates the checksum of Q subchannel data(not including the checksum bytes of course ;)) from subq_buf, and stores it into the appropriate position
 // in subq_buf.
 void subq_generate_checksum(uint8 *subq_buf);

 // Deinterleaves 12 bytes of subchannel Q data from 96 bytes of interleaved subchannel PW data.
 void subq_deinterleave(const uint8 *subpw_buf, uint8 *subq_buf);

 // Deinterleaves 96 bytes of subchannel P-W data from 96 bytes of interleaved subchannel PW data.
 void subpw_deinterleave(const uint8 *in_buf, uint8 *out_buf);

 // Interleaves 96 bytes of subchannel P-W data from 96 bytes of uninterleaved subchannel PW data.
 void subpw_interleave(const uint8 *in_buf, uint8 *out_buf);

 // Extrapolates Q subchannel current position data from subq_input, with frame/sector delta position_delta, and writes to subq_output.
 // Only valid for ADR_CURPOS.
 // subq_input must pass subq_check_checksum().
 // TODO
 //void subq_extrapolate(const uint8 *subq_input, int32 position_delta, uint8 *subq_output);

 // (De)Scrambles data sector.
 void scrambleize_data_sector(uint8 *sector_data);
}

#endif