coder.h

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/* ***** BEGIN LICENSE BLOCK ***** 
 * Version: RCSL 1.0/RPSL 1.0 
 *  
 * Portions Copyright (c) 1995-2002 RealNetworks, Inc. All Rights Reserved. 
 *      
 * The contents of this file, and the files included with this file, are 
 * subject to the current version of the RealNetworks Public Source License 
 * Version 1.0 (the "RPSL") available at 
 * http://www.helixcommunity.org/content/rpsl unless you have licensed 
 * the file under the RealNetworks Community Source License Version 1.0 
 * (the "RCSL") available at http://www.helixcommunity.org/content/rcsl, 
 * in which case the RCSL will apply. You may also obtain the license terms 
 * directly from RealNetworks.  You may not use this file except in 
 * compliance with the RPSL or, if you have a valid RCSL with RealNetworks 
 * applicable to this file, the RCSL.  Please see the applicable RPSL or 
 * RCSL for the rights, obligations and limitations governing use of the 
 * contents of the file.  
 *  
 * This file is part of the Helix DNA Technology. RealNetworks is the 
 * developer of the Original Code and owns the copyrights in the portions 
 * it created. 
 *  
 * This file, and the files included with this file, is distributed and made 
 * available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 
 * EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS ALL SUCH WARRANTIES, 
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 * FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 
 * 
 * Technology Compatibility Kit Test Suite(s) Location: 
 *    http://www.helixcommunity.org/content/tck 
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 * Contributor(s): 
 *  
 * ***** END LICENSE BLOCK ***** */ 
 
/**************************************************************************************
 * Fixed-point MP3 decoder
 * Jon Recker (jrecker@real.com), Ken Cooke (kenc@real.com)
 * June 2003
 *
 * coder.h - private, implementation-specific header file
 **************************************************************************************/
 
#ifndef _CODER_H
#define _CODER_H
 
#include "mp3common.h"
 
#if defined(ASSERT)
#undef ASSERT
#endif
#if defined(_WIN32) && defined(_M_IX86) && (defined (_DEBUG) || defined (REL_ENABLE_ASSERTS))
#define ASSERT(x) if (!(x)) __asm int 3;
#else
#define ASSERT(x) /* do nothing */
#endif
 
#ifndef MAX
#define MAX(a,b)  ((a) > (b) ? (a) : (b))
#endif
 
#ifndef MIN
#define MIN(a,b)  ((a) < (b) ? (a) : (b))
#endif
 
/* clip to range [-2^n, 2^n - 1] */
#define CLIP_2N(y, n) { \
  int sign = (y) >> 31;  \
  if (sign != (y) >> (n))  { \
    (y) = sign ^ ((1 << (n)) - 1); \
  } \
}
 
#define SIBYTES_MPEG1_MONO    17
#define SIBYTES_MPEG1_STEREO  32
#define SIBYTES_MPEG2_MONO     9
#define SIBYTES_MPEG2_STEREO  17
 
/* number of fraction bits for pow43Tab (see comments there) */
#define POW43_FRACBITS_LOW    22
#define POW43_FRACBITS_HIGH   12
 
#define DQ_FRACBITS_OUT     25  /* number of fraction bits in output of dequant */
#define IMDCT_SCALE       2 /* additional scaling (by sqrt(2)) for fast IMDCT36 */
 
#define HUFF_PAIRTABS     32
#define BLOCK_SIZE        18
#define NBANDS          32
#define MAX_REORDER_SAMPS   ((192-126)*3)   /* largest critical band for short blocks (see sfBandTable) */
#define VBUF_LENGTH       (17 * 2 * NBANDS) /* for double-sized vbuf FIFO */
 
/* additional external symbols to name-mangle for static linking */
#define SetBitstreamPointer STATNAME(SetBitstreamPointer)
#define GetBits       STATNAME(GetBits)
#define CalcBitsUsed    STATNAME(CalcBitsUsed)
#define DequantChannel    STATNAME(DequantChannel)
#define MidSideProc     STATNAME(MidSideProc)
#define IntensityProcMPEG1  STATNAME(IntensityProcMPEG1)
#define IntensityProcMPEG2  STATNAME(IntensityProcMPEG2)
#define PolyphaseMono   STATNAME(PolyphaseMono)
#define PolyphaseStereo   STATNAME(PolyphaseStereo)
#define FDCT32        STATNAME(FDCT32)
 
#define ISFMpeg1      STATNAME(ISFMpeg1)
#define ISFMpeg2      STATNAME(ISFMpeg2)
#define ISFIIP        STATNAME(ISFIIP)
#define uniqueIDTab     STATNAME(uniqueIDTab)
#define coef32        STATNAME(coef32)
#define polyCoef      STATNAME(polyCoef)
#define csa         STATNAME(csa)
#define imdctWin      STATNAME(imdctWin)
 
#define huffTable     STATNAME(huffTable)
#define huffTabOffset   STATNAME(huffTabOffset)
#define huffTabLookup   STATNAME(huffTabLookup)
#define quadTable     STATNAME(quadTable)
#define quadTabOffset   STATNAME(quadTabOffset)
#define quadTabMaxBits    STATNAME(quadTabMaxBits)
 
/* map these to the corresponding 2-bit values in the frame header */
typedef enum {
  Stereo = 0x00,  /* two independent channels, but L and R frames might have different # of bits */
  Joint = 0x01, /* coupled channels - layer III: mix of M-S and intensity, Layers I/II: intensity and direct coding only */
  Dual = 0x02,  /* two independent channels, L and R always have exactly 1/2 the total bitrate */
  Mono = 0x03   /* one channel */
} StereoMode;
 
typedef struct _BitStreamInfo {
  unsigned char *bytePtr;
  unsigned int iCache;
  int cachedBits;
  int nBytes;
} BitStreamInfo;
 
typedef struct _FrameHeader {
    MPEGVersion ver;  /* version ID */
    int layer;      /* layer index (1, 2, or 3) */
    int crc;      /* CRC flag: 0 = disabled, 1 = enabled */
    int brIdx;      /* bitrate index (0 - 15) */
    int srIdx;      /* sample rate index (0 - 2) */
    int paddingBit;   /* padding flag: 0 = no padding, 1 = single pad byte */
    int privateBit;   /* unused */
    StereoMode sMode; /* mono/stereo mode */
    int modeExt;    /* used to decipher joint stereo mode */
    int copyFlag;   /* copyright flag: 0 = no, 1 = yes */
    int origFlag;   /* original flag: 0 = copy, 1 = original */
    int emphasis;   /* deemphasis mode */
    int CRCWord;    /* CRC word (16 bits, 0 if crc not enabled) */
 
  const SFBandTable *sfBand;
} FrameHeader;
 
typedef struct _SideInfoSub {
    int part23Length;   /* number of bits in main data */ 
    int nBigvals;     /* 2x this = first set of Huffman cw's (maximum amplitude can be > 1) */
    int globalGain;     /* overall gain for dequantizer */
    int sfCompress;     /* unpacked to figure out number of bits in scale factors */
    int winSwitchFlag;    /* window switching flag */
    int blockType;      /* block type */
    int mixedBlock;     /* 0 = regular block (all short or long), 1 = mixed block */
    int tableSelect[3];   /* index of Huffman tables for the big values regions */
    int subBlockGain[3];  /* subblock gain offset, relative to global gain */
    int region0Count;   /* 1+region0Count = num scale factor bands in first region of bigvals */
    int region1Count;   /* 1+region1Count = num scale factor bands in second region of bigvals */
    int preFlag;      /* for optional high frequency boost */
    int sfactScale;     /* scaling of the scalefactors */
    int count1TableSelect;  /* index of Huffman table for quad codewords */
} SideInfoSub;
 
typedef struct _SideInfo {
  int mainDataBegin;
  int privateBits;
  int scfsi[MAX_NCHAN][MAX_SCFBD];        /* 4 scalefactor bands per channel */
  
  SideInfoSub sis[MAX_NGRAN][MAX_NCHAN];
} SideInfo;
 
typedef struct {
    int cbType;   /* pure long = 0, pure short = 1, mixed = 2 */
    int cbEndS[3];  /* number nonzero short cb's, per subbblock */
  int cbEndSMax;  /* max of cbEndS[] */
    int cbEndL;   /* number nonzero long cb's  */
} CriticalBandInfo;
 
typedef struct _DequantInfo {
  int workBuf[MAX_REORDER_SAMPS];   /* workbuf for reordering short blocks */
  CriticalBandInfo cbi[MAX_NCHAN];  /* filled in dequantizer, used in joint stereo reconstruction */
} DequantInfo;
 
typedef struct _HuffmanInfo {
  int huffDecBuf[MAX_NCHAN][MAX_NSAMP];   /* used both for decoded Huffman values and dequantized coefficients */
  int nonZeroBound[MAX_NCHAN];        /* number of coeffs in huffDecBuf[ch] which can be > 0 */
  int gb[MAX_NCHAN];              /* minimum number of guard bits in huffDecBuf[ch] */
} HuffmanInfo;
 
typedef enum _HuffTabType {
  noBits,
  oneShot,
  loopNoLinbits,
  loopLinbits,
  quadA,
  quadB,
  invalidTab
} HuffTabType;
 
typedef struct _HuffTabLookup {
  int linBits;
  HuffTabType tabType;
} HuffTabLookup;
 
typedef struct _IMDCTInfo {
  int outBuf[MAX_NCHAN][BLOCK_SIZE][NBANDS];  /* output of IMDCT */ 
  int overBuf[MAX_NCHAN][MAX_NSAMP / 2];    /* overlap-add buffer (by symmetry, only need 1/2 size) */
  int numPrevIMDCT[MAX_NCHAN];        /* how many IMDCT's calculated in this channel on prev. granule */
  int prevType[MAX_NCHAN];
  int prevWinSwitch[MAX_NCHAN];
  int gb[MAX_NCHAN];
} IMDCTInfo;
 
typedef struct _BlockCount {
  int nBlocksLong;
  int nBlocksTotal;
  int nBlocksPrev; 
  int prevType;
  int prevWinSwitch;
  int currWinSwitch;
  int gbIn;
  int gbOut;
} BlockCount;
 
/* max bits in scalefactors = 5, so use char's to save space */
typedef struct _ScaleFactorInfoSub {
  char l[23];            /* [band] */
  char s[13][3];         /* [band][window] */
} ScaleFactorInfoSub;  
 
/* used in MPEG 2, 2.5 intensity (joint) stereo only */
typedef struct _ScaleFactorJS {
  int intensityScale;   
  int slen[4];
  int nr[4];
} ScaleFactorJS;
 
typedef struct _ScaleFactorInfo {
  ScaleFactorInfoSub sfis[MAX_NGRAN][MAX_NCHAN];
  ScaleFactorJS sfjs;
} ScaleFactorInfo;
 
/* NOTE - could get by with smaller vbuf if memory is more important than speed
 *  (in Subband, instead of replicating each block in FDCT32 you would do a memmove on the
 *   last 15 blocks to shift them down one, a hardware style FIFO)
 */ 
typedef struct _SubbandInfo {
  int vbuf[MAX_NCHAN * VBUF_LENGTH];    /* vbuf for fast DCT-based synthesis PQMF - double size for speed (no modulo indexing) */
  int vindex;               /* internal index for tracking position in vbuf */
} SubbandInfo;
 
/* bitstream.c */
void SetBitstreamPointer(BitStreamInfo *bsi, int nBytes, unsigned char *buf);
unsigned int GetBits(BitStreamInfo *bsi, int nBits);
int CalcBitsUsed(BitStreamInfo *bsi, unsigned char *startBuf, int startOffset);
 
/* dequant.c, dqchan.c, stproc.c */
int DequantChannel(int *sampleBuf, int *workBuf, int *nonZeroBound, FrameHeader *fh, SideInfoSub *sis, 
          ScaleFactorInfoSub *sfis, CriticalBandInfo *cbi);
void MidSideProc(int x[MAX_NCHAN][MAX_NSAMP], int nSamps, int mOut[2]);
void IntensityProcMPEG1(int x[MAX_NCHAN][MAX_NSAMP], int nSamps, FrameHeader *fh, ScaleFactorInfoSub *sfis, 
            CriticalBandInfo *cbi, int midSideFlag, int mixFlag, int mOut[2]);
void IntensityProcMPEG2(int x[MAX_NCHAN][MAX_NSAMP], int nSamps, FrameHeader *fh, ScaleFactorInfoSub *sfis, 
            CriticalBandInfo *cbi, ScaleFactorJS *sfjs, int midSideFlag, int mixFlag, int mOut[2]);
 
/* dct32.c */
// about 1 ms faster in RAM, but very large
void FDCT32(int *x, int *d, int offset, int oddBlock, int gb);// __attribute__ ((section (".data")));
 
/* hufftabs.c */
extern const HuffTabLookup huffTabLookup[HUFF_PAIRTABS];
extern const int huffTabOffset[HUFF_PAIRTABS];
extern const unsigned short huffTable[];
extern const unsigned char quadTable[64+16];
extern const int quadTabOffset[2];
extern const int quadTabMaxBits[2];
 
/* polyphase.c (or asmpoly.s)
 * some platforms require a C++ compile of all source files,
 * so if we're compiling C as C++ and using native assembly
 * for these functions we need to prevent C++ name mangling.
 */
#ifdef __cplusplus
extern "C" {
#endif
void PolyphaseMono(short *pcm, int *vbuf, const int *coefBase);
void PolyphaseStereo(short *pcm, int *vbuf, const int *coefBase);
#ifdef __cplusplus
}
#endif
 
/* trigtabs.c */
extern const int imdctWin[4][36];
extern const int ISFMpeg1[2][7];
extern const int ISFMpeg2[2][2][16];
extern const int ISFIIP[2][2];
extern const int csa[8][2];
extern const int coef32[31];
extern const int polyCoef[264];
 
#endif  /* _CODER_H */