ac3dec_parse.cpp

这是在PCA下的基于IPP库示例代码例子,在网上下了IPP的库之后,设置相关参数就可以编译该代码.

/*//////////////////////////////////////////////////////////////////////////////
//
//                  INTEL CORPORATION PROPRIETARY INFORMATION
//     This software is supplied under the terms of a license agreement or
//     nondisclosure agreement with Intel Corporation and may not be copied
//     or disclosed except in accordance with the terms of that agreement.
//          Copyright(c) 2002-2005 Intel Corporation. All Rights Reserved.
//
*/
#include "umc_ac3_decoder.h"
#include "ac3dec_tables.h"

#ifdef _BIG_ENDIAN_
#define BSWAP(x) (x)
#else
#define BSWAP(x) (Ipp32u)(((x) << 24) | (((x)&0xff00) << 8) | (((x) >> 8)&0xff00) | ((x&0xff000000) >> 24));
#endif

static unsigned int table[33] = {
  0x00000000,
  0x00000001,
  0x00000003,
  0x00000007,
  0x0000000F,
  0x0000001F,
  0x0000003F,
  0x0000007F,
  0x000000FF,
  0x000001FF,
  0x000003FF,
  0x000007FF,
  0x00000FFF,
  0x00001FFF,
  0x00003FFF,
  0x00007FFF,
  0x0000FFFF,
  0x0001FFFF,
  0x0003FFFF,
  0x0007FFFF,
  0x000FFFFF,
  0x001FFFFF,
  0x003FFFFF,
  0x007FFFFF,
  0x00FFFFFF,
  0x01FFFFFF,
  0x03FFFFFF,
  0x07FFFFFF,
  0x0FFFFFFF,
  0x1FFFFFFF,
  0x3FFFFFFF,
  0x7FFFFFFF,
  0xFFFFFFFF,
};

int UMC::AC3Decoder::getbits(int n)
{
  unsigned int cw = 0;

  dataBuffer.total_bits_read += n;

  if (dataBuffer.iBitOffset < n) {
    cw = dataBuffer.cw & table[dataBuffer.iBitOffset];

    dataBuffer.iDWDoneNum++;
    dataBuffer.cw = BSWAP(*(dataBuffer.pBuffer + dataBuffer.iDWDoneNum));

    n -= dataBuffer.iBitOffset;
    cw = cw << n;
    dataBuffer.iBitOffset = 32;
  }

  dataBuffer.iBitOffset -= n;
  cw |= (dataBuffer.cw >> (dataBuffer.iBitOffset)) & table[n];

  return cw;
}

int UMC::AC3Decoder::ParseSyncInfo()
{
 /* Get crc1 - we don't actually use this data though */
  getbits(16);

 /* Get the sampling rate */
  syncinfo.fscod = (Ipp16u)getbits(2);
  if (syncinfo.fscod == 3)
    return 1;

 /* Get the frame size code */
  syncinfo.frmsizecod = (Ipp16u)getbits(6);
  if (syncinfo.frmsizecod > 37)
    return -1;

 /* Parse information */
  syncinfo.SampleRate = (float)SAMPLING_RATE[syncinfo.fscod];
  syncinfo.bit_rate = FRAMESIZECODE[syncinfo.frmsizecod].bit_rate;
  syncinfo.frame_size =
    FRAMESIZECODE[syncinfo.frmsizecod].frm_size[syncinfo.fscod];

  return 0;
}

static const float dialnormTable[32] = {
  1.0000000000f, 0.0312500000f, 0.0350769386f, 0.0393725336f,
  0.0441941731f, 0.0496062823f, 0.0556811690f, 0.0625000000f,
  0.0701538771f, 0.0787450671f, 0.0883883461f, 0.0992125645f,
  0.1113623381f, 0.1250000000f, 0.1403077543f, 0.1574901342f,
  0.1767766923f, 0.1984251291f, 0.2227246761f, 0.2500000000f,
  0.2806155086f, 0.3149802685f, 0.3535533845f, 0.3968502581f,
  0.4454493523f, 0.5000000000f, 0.5612310171f, 0.6299605370f,
  0.7071067691f, 0.7937005162f, 0.8908987045f, 1.0000000000f
};

int UMC::AC3Decoder::ParseBsi()
{
  int i, tmp;

 /* Check the AC-3 version number */
  bsi.bsid = (Ipp16u)getbits(5);
  if (bsi.bsid > 8)
    return -2;

 /* Get the audio service provided by the stream */
  bsi.bsmod = (Ipp16u)getbits(3);

 /* Get the audio coding mode (ie how many channels) */
  bsi.acmod = (Ipp16u)getbits(3);

  bsi.karaokeMode = 0;
  if ((bsi.bsmod == 7) && (bsi.acmod > 1)) {
    bsi.karaokeMode = 1;
  }

 /* Predecode the number of full bandwidth channels as we use this number a lot */
  bsi.nfchans = NFCHANS[bsi.acmod];

 /* If it is in use, get the centre channel mix level */
  if ((bsi.acmod & 0x1) && (bsi.acmod != 0x1))
    bsi.cmixlev = (Ipp16u)getbits(2);

 /* If it is in use, get the surround channel mix level */
  if (bsi.acmod & 0x4)
    bsi.surmixlev = (Ipp16u)getbits(2);

 /* Get the dolby surround mode if in 2/0 mode */
  if (bsi.acmod == 0x2)
    bsi.dsurmod = (Ipp16u)getbits(2);

 /* Is the low frequency effects channel on? */
  bsi.lfeon = (Ipp16u)getbits(1);

 /* Get the dialogue normalization level */
  tmp = (Ipp32s)getbits(5);
  bsi.dialnorm = dialnormTable[tmp];

 /* Does compression gain exist? */
  bsi.compre = (Ipp16u)getbits(1);
  if (bsi.compre) {
 /* Get compression gain */
    tmp = (Ipp32s)getbits(8);
    bsi.compr = (tmp << 24) >> 8;
  }

 /* Does language code exist? */
  bsi.langcode = (Ipp16u)getbits(1);
  if (bsi.langcode) {
 /* Get langauge code */
    bsi.langcod = (Ipp16u)getbits(8);
  }

 /* Does audio production info exist? */
  bsi.audprodie = (Ipp16u)getbits(1);
  if (bsi.audprodie) {
 /* Get mix level */
    bsi.mixlevel = (Ipp16u)getbits(5);

 /* Get room type */
    bsi.roomtyp = (Ipp16u)getbits(2);
  }

 /* If we're in dual mono mode then get some extra info */
  if (bsi.acmod == 0) {
 /* Get the dialogue normalization level two */
    tmp = (Ipp32s)getbits(5);
    bsi.dialnorm2 = dialnormTable[tmp];

 /* Does compression gain two exist? */
    bsi.compr2e = (Ipp16u)getbits(1);
    if (bsi.compr2e) {
 /* Get compression gain two */
      tmp = (Ipp32s)getbits(8);
      bsi.compr2 = (tmp << 24) >> 8;
    }

 /* Does language code two exist? */
    bsi.langcod2e = (Ipp16u)getbits(1);
    if (bsi.langcod2e) {
 /* Get langauge code two */
      bsi.langcod2 = (Ipp16u)getbits(8);
    }

 /* Does audio production info two exist? */
    bsi.audprodi2e = (Ipp16u)getbits(1);
    if (bsi.audprodi2e) {
 /* Get mix level two */
      bsi.mixlevel2 = (Ipp16u)getbits(5);

 /* Get room type two */
      bsi.roomtyp2 = (Ipp16u)getbits(2);
    }
  }

 /* Get the c o p y r i g h t  b i t */
  bsi.copyrightb = (Ipp16u)getbits(1);

 /* Get the original bit */
  bsi.origbs = (Ipp16u)getbits(1);

 /* Does timecode one exist? */
  bsi.timecod1e = (Ipp16u)getbits(1);

  if (bsi.timecod1e)
    bsi.timecod1 = (Ipp16u)getbits(14);

 /* Does timecode two exist? */
  bsi.timecod2e = (Ipp16u)getbits(1);

  if (bsi.timecod2e)
    bsi.timecod2 = (Ipp16u)getbits(14);

 /* Does addition info exist? */
  bsi.addbsie = (Ipp16u)getbits(1);

  if (bsi.addbsie) {
 /* Get how much info is there */
    bsi.addbsil = (Ipp16u)getbits(6);

 /* Get the additional info */
    for (i = 0; i < (int)(bsi.addbsil + 1); i++)
      bsi.addbsi[i] = (Ipp8u)getbits(8);
  }

  return 0;
}

int UMC::AC3Decoder::ParseAudblk(int nblk)
{
  int ncplsubnd;
  int tmp;
  int i, j;

  if (nblk == 0) {      /* audioblock 0? If so, reset these parameters */
    audblk[nblk]->dynrng = 0;
    audblk[nblk]->dynrng2 = 0;
    audblk[nblk]->cpldeltnseg = 0;

    for (i = 0; i < bsi.nfchans; i++) {
      audblk[nblk]->deltnseg[i] = 0;
    }

    for (i = 0; i < 18; i++) {
      audblk[nblk]->phscor[i] = 0;
    }
    audblk[nblk]->phsoutmod = 7;
  }

  for (i = 0; i < bsi.nfchans; i++) {
 /* Is this channel an interleaved ? */
    audblk[nblk]->blksw[i] = (Ipp16u)(getbits(1));
  }

  for (i = 0; i < bsi.nfchans; i++) {
 /* Should we dither this channel? */
    audblk[nblk]->dithflag[i] = (Ipp16u)(getbits(1));
  }

 /* Does dynamic range control exist? */
  audblk[nblk]->dynrnge = (Ipp16u)(getbits(1));
  if (audblk[nblk]->dynrnge) {
 /* Get dynamic range info */
    tmp = (Ipp32s)(getbits(8));
    audblk[nblk]->dynrng = (tmp << 24) >> 9;
  }

 /* If we're in dual mono mode then get the second channel DR info */
  if (bsi.acmod == 0) {
 /* Does dynamic range control two exist? */
    audblk[nblk]->dynrng2e = (Ipp16u)(getbits(1));
    if (audblk[nblk]->dynrng2e) {
 /* Get dynamic range info */
      tmp = (Ipp32s)(getbits(8));
      audblk[nblk]->dynrng2 = (tmp << 24) >> 9;
    }
  }

 /* Does coupling strategy exist? */
  audblk[nblk]->cplstre = (Ipp16u)(getbits(1));

  if ((nblk == 0) && (audblk[nblk]->cplstre == 0)) {
    return 0;
  }

  if (audblk[nblk]->cplstre) {
 /* Is coupling turned on? */
    audblk[nblk]->cplinu = (Ipp16u)(getbits(1));
    if (audblk[nblk]->cplinu) {
      for (i = 0; i < bsi.nfchans; i++)
        audblk[nblk]->chincpl[i] = (Ipp16u)(getbits(1));

      if (bsi.acmod == 0x2)
        audblk[nblk]->phsflginu = (Ipp16u)(getbits(1));
      else
        audblk[nblk]->phsflginu = 0;

      audblk[nblk]->cplbegf = (Ipp16u)(getbits(4));
      audblk[nblk]->cplendf = (Ipp16u)(getbits(4));
      ncplsubnd = (int)audblk[nblk]->cplendf - audblk[nblk]->cplbegf + 3;

 /* Calculate the start and end bins of the coupling channel */
      audblk[nblk]->cplstrtmant = (Ipp16u)((audblk[nblk]->cplbegf * 12) + 37);
      audblk[nblk]->cplendmant =
        (Ipp16u)(((audblk[nblk]->cplendf + 3) * 12) + 37);

 /* The number of combined subbands is ncplsubnd minus each combined band */
      audblk[nblk]->ncplbnd = (Ipp16u)ncplsubnd;
      audblk[nblk]->cplbndstrc[0] = 0;
      for (i = 1; i < ncplsubnd; i++) {
        audblk[nblk]->cplbndstrc[i] = (Ipp16u)(getbits(1));
#ifndef REF_DECODER_COMPATIBLE
        audblk[nblk]->ncplbnd -= (int)audblk[nblk]->cplbndstrc[i];
#endif
      }

    } else {
      for (i = 0; i < bsi.nfchans; i++)
        audblk[nblk]->chincpl[i] = 0;

      audblk[nblk]->phsflginu = 0;
    }
  }

  if (audblk[nblk]->cplinu) {
 /* Loop through all the channels and get their coupling co-ords */
    for (i = 0; i < bsi.nfchans; i++) {