tpdec_latm.cpp - Android社区 - https://www.androidos.net.cn/

/* -----------------------------------------------------------------------------------------------------------
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5.    CONTACT INFORMATION

Fraunhofer Institute for Integrated Circuits IIS
Attention: Audio and Multimedia Departments - FDK AAC LL
Am Wolfsmantel 33
91058 Erlangen, Germany

www.iis.fraunhofer.de/amm
amm-info@iis.fraunhofer.de
----------------------------------------------------------------------------------------------------------- */

/*****************************  MPEG-4 AAC Decoder  **************************

Author(s):   Daniel Homm
   Description:

******************************************************************************/

#include "tpdec_latm.h"

#include "FDK_bitstream.h"

#define TPDEC_TRACKINDEX(p,l) (2*(p) + (l))

static
UINT CLatmDemux_GetValue(HANDLE_FDK_BITSTREAM bs)
{
  UCHAR bytesForValue = 0, tmp = 0;
  int value = 0;

bytesForValue = (UCHAR) FDKreadBits(bs,2);

for (UINT i=0; i<=bytesForValue; i++) {
    value <<= 8;
    tmp = (UCHAR) FDKreadBits(bs,8);
    value += tmp;
  }

return value;
}

static
TRANSPORTDEC_ERROR CLatmDemux_ReadAudioMuxElement(
        HANDLE_FDK_BITSTREAM bs,
        CLatmDemux *pLatmDemux,
        int m_muxConfigPresent,
        CSTpCallBacks *pTpDecCallbacks,
        CSAudioSpecificConfig *pAsc
        )
{
  TRANSPORTDEC_ERROR ErrorStatus = TRANSPORTDEC_OK;

if (m_muxConfigPresent) {
    pLatmDemux->m_useSameStreamMux = FDKreadBits(bs,1);

if (!pLatmDemux->m_useSameStreamMux) {
      if ((ErrorStatus = CLatmDemux_ReadStreamMuxConfig(bs, pLatmDemux, pTpDecCallbacks, pAsc))) {
        return (ErrorStatus);
      }
    }
  }

if (pLatmDemux->m_AudioMuxVersionA == 0) {
    /* Do only once per call, because parsing and decoding is done in-line. */
    if ((ErrorStatus = CLatmDemux_ReadPayloadLengthInfo(bs,pLatmDemux))) {
      return (ErrorStatus);
    }
  } else {
    /* audioMuxVersionA > 0 is reserved for future extensions */
    ErrorStatus = TRANSPORTDEC_UNSUPPORTED_FORMAT;
  }

return (ErrorStatus);
}

TRANSPORTDEC_ERROR CLatmDemux_Read(
        HANDLE_FDK_BITSTREAM bs,
        CLatmDemux *pLatmDemux,
        TRANSPORT_TYPE tt,
        CSTpCallBacks *pTpDecCallbacks,
        CSAudioSpecificConfig *pAsc,
        const INT ignoreBufferFullness
        )
{
  UINT cntBits;
  UINT cmpBufferFullness;
  UINT audioMuxLengthBytesLast = 0;
  TRANSPORTDEC_ERROR ErrorStatus = TRANSPORTDEC_OK;

cntBits = FDKgetValidBits(bs);

if ((INT)cntBits < MIN_LATM_HEADERLENGTH) {
    return TRANSPORTDEC_NOT_ENOUGH_BITS;
  }

if ((ErrorStatus = CLatmDemux_ReadAudioMuxElement(bs, pLatmDemux, (tt != TT_MP4_LATM_MCP0), pTpDecCallbacks, pAsc)))
    return (ErrorStatus);

if (!ignoreBufferFullness)
  {
    cmpBufferFullness =   24+audioMuxLengthBytesLast*8
                        + pLatmDemux->m_linfo[0][0].m_bufferFullness* pAsc[TPDEC_TRACKINDEX(0,0)].m_channelConfiguration*32;

/* evaluate buffer fullness */

if (pLatmDemux->m_linfo[0][0].m_bufferFullness != 0xFF)
    {
      if (!pLatmDemux->BufferFullnessAchieved)
      {
        if (cntBits < cmpBufferFullness)
        {
          /* condition for start of decoding is not fulfilled */

/* the current frame will not be decoded */
          return TRANSPORTDEC_NOT_ENOUGH_BITS;
        }
        else
        {
          pLatmDemux->BufferFullnessAchieved = 1;
        }
      }
    }
  }

return (ErrorStatus);
}

TRANSPORTDEC_ERROR CLatmDemux_ReadStreamMuxConfig(
        HANDLE_FDK_BITSTREAM bs,
        CLatmDemux *pLatmDemux,
        CSTpCallBacks *pTpDecCallbacks,
        CSAudioSpecificConfig *pAsc
        )
{
  LATM_LAYER_INFO *p_linfo = NULL;
  TRANSPORTDEC_ERROR ErrorStatus = TRANSPORTDEC_OK;

pLatmDemux->m_AudioMuxVersion = FDKreadBits(bs,1);

if (pLatmDemux->m_AudioMuxVersion == 0) {
    pLatmDemux->m_AudioMuxVersionA = 0;
  } else {
    pLatmDemux->m_AudioMuxVersionA = FDKreadBits(bs,1);
  }

if (pLatmDemux->m_AudioMuxVersionA == 0) {
    if (pLatmDemux->m_AudioMuxVersion == 1) {
      pLatmDemux->m_taraBufferFullness = CLatmDemux_GetValue(bs);
    }
    pLatmDemux->m_allStreamsSameTimeFraming = FDKreadBits(bs,1);
    pLatmDemux->m_noSubFrames = FDKreadBits(bs,6) + 1;
    pLatmDemux->m_numProgram  = FDKreadBits(bs,4) + 1;

if (pLatmDemux->m_numProgram > 1) {
      return TRANSPORTDEC_UNSUPPORTED_FORMAT;
    }

int idCnt = 0;
    for (UINT prog = 0; prog < pLatmDemux->m_numProgram; prog++) {
      pLatmDemux->m_numLayer = FDKreadBits(bs,3) + 1;
      if (pLatmDemux->m_numLayer > 2) {
        return TRANSPORTDEC_UNSUPPORTED_FORMAT;
      }

for (UINT lay = 0; lay < pLatmDemux->m_numLayer; lay++) {
        p_linfo = &pLatmDemux->m_linfo[prog][lay];

p_linfo->m_streamID = idCnt++;
        p_linfo->m_frameLengthInBits = 0;

if( (prog == 0) && (lay == 0) ) {
          pLatmDemux->m_useSameConfig = 0;
        } else {
          pLatmDemux->m_useSameConfig = FDKreadBits(bs,1);
        }

if (pLatmDemux->m_useSameConfig) {
          if (lay > 1) {
            FDKmemcpy(&pAsc[TPDEC_TRACKINDEX(prog,lay)], &pAsc[TPDEC_TRACKINDEX(prog,lay-1)], sizeof(CSAudioSpecificConfig));
          } else {
            return TRANSPORTDEC_PARSE_ERROR;
          }
        } else {
          if (pLatmDemux->m_AudioMuxVersion == 1)
          {
            FDK_BITSTREAM tmpBs;
            UINT ascStartPos, ascLen=0;

ascLen = CLatmDemux_GetValue(bs);
            ascStartPos = FDKgetValidBits(bs);
            tmpBs = *bs;
            FDKsyncCache(&tmpBs);
            tmpBs.hBitBuf.ValidBits = ascLen;
            
            /* Read ASC */
            if ((ErrorStatus = AudioSpecificConfig_Parse(&pAsc[TPDEC_TRACKINDEX(prog,lay)], &tmpBs, 1, pTpDecCallbacks))) {
              return (ErrorStatus);
            }

/* The field p_linfo->m_ascLen could be wrong, so check if */
            if ( 0 > (INT)FDKgetValidBits(&tmpBs)) {
              return TRANSPORTDEC_PARSE_ERROR;
            }
            FDKpushFor(bs, ascLen); /* position bitstream after ASC */
          }
          else {
            /* Read ASC */
            if ((ErrorStatus = AudioSpecificConfig_Parse(&pAsc[TPDEC_TRACKINDEX(prog,lay)], bs, 0, pTpDecCallbacks))) {
              return (ErrorStatus);
            }
          }
          {
            int cbError;

cbError = pTpDecCallbacks->cbUpdateConfig(pTpDecCallbacks->cbUpdateConfigData, &pAsc[TPDEC_TRACKINDEX(prog,lay)]);
            if (cbError != 0) {
              return TRANSPORTDEC_UNKOWN_ERROR;
            }
          }
        }

p_linfo->m_frameLengthType = FDKreadBits(bs,3);
        switch( p_linfo->m_frameLengthType ) {
        case 0:
          p_linfo->m_bufferFullness = FDKreadBits(bs,8);

if (!pLatmDemux->m_allStreamsSameTimeFraming) {
            if ((lay > 0) && (pAsc[TPDEC_TRACKINDEX(prog,lay)].m_aot == AOT_AAC_SCAL || pAsc[TPDEC_TRACKINDEX(prog,lay)].m_aot == AOT_ER_AAC_SCAL)) {
              return TRANSPORTDEC_UNSUPPORTED_FORMAT;
            }
          }
          break;
        case 1:
          /* frameLength = FDKreadBits(bs,9); */
        case 3:
        case 4:
        case 5:
          /* CELP */
        case 6:
        case 7:
          /* HVXC */
        default:
          return TRANSPORTDEC_PARSE_ERROR; //_LATM_INVALIDFRAMELENGTHTYPE;

}  /* switch framelengthtype*/

}  /* layer loop */
    }  /* prog loop */

pLatmDemux->m_otherDataPresent = FDKreadBits(bs,1);
    pLatmDemux->m_otherDataLength  = 0;

if (pLatmDemux->m_otherDataPresent) {
      int otherDataLenEsc  = 0;
      do {
        pLatmDemux->m_otherDataLength <<= 8;   // *= 256
        otherDataLenEsc = FDKreadBits(bs,1);
        pLatmDemux->m_otherDataLength += FDKreadBits(bs,8);
      } while (otherDataLenEsc);
    }

pLatmDemux->m_crcCheckPresent = FDKreadBits(bs,1);
    pLatmDemux->m_crcCheckSum     = 0;

if (pLatmDemux->m_crcCheckPresent) {
      pLatmDemux->m_crcCheckSum = FDKreadBits(bs,8);
    }

}
  else {
    /* audioMuxVersionA > 0 is reserved for future extensions */
    ErrorStatus = TRANSPORTDEC_UNSUPPORTED_FORMAT;
  }
  return (ErrorStatus);
}

TRANSPORTDEC_ERROR CLatmDemux_ReadPayloadLengthInfo(HANDLE_FDK_BITSTREAM bs, CLatmDemux *pLatmDemux)
{
  TRANSPORTDEC_ERROR ErrorStatus = TRANSPORTDEC_OK;
  int totalPayloadBits = 0;

if( pLatmDemux->m_allStreamsSameTimeFraming == 1 ) {
    for (UINT prog=0; prog<pLatmDemux->m_numProgram; prog++ ) {
      for (UINT lay=0; lay<pLatmDemux->m_numLayer; lay++ ) {
        LATM_LAYER_INFO *p_linfo = &pLatmDemux->m_linfo[prog][lay];

switch (p_linfo->m_frameLengthType ) {
        case 0:
          p_linfo->m_frameLengthInBits = CLatmDemux_ReadAuChunkLengthInfo(bs);
          totalPayloadBits += p_linfo->m_frameLengthInBits;
          break;
        case 3:
        case 5:
        case 7:
        default:
          return TRANSPORTDEC_PARSE_ERROR; //AAC_DEC_LATM_INVALIDFRAMELENGTHTYPE;
        }
      }
    }
  }
  else {
    ErrorStatus = TRANSPORTDEC_PARSE_ERROR; //AAC_DEC_LATM_TIMEFRAMING;
  }
  if (pLatmDemux->m_audioMuxLengthBytes > 0 && totalPayloadBits > pLatmDemux->m_audioMuxLengthBytes*8) {
    return TRANSPORTDEC_PARSE_ERROR;
  }
  return (ErrorStatus);
}

int CLatmDemux_ReadAuChunkLengthInfo(HANDLE_FDK_BITSTREAM bs)
{
  UCHAR endFlag;
  int len = 0;

do {
    UCHAR tmp = (UCHAR) FDKreadBits(bs,8);
    endFlag = (tmp < 255);

len += tmp;

} while( endFlag == 0 );

len <<= 3;  /* convert from bytes to bits */

return len;
}

int CLatmDemux_GetFrameLengthInBits(CLatmDemux *pLatmDemux)
{
  return pLatmDemux->m_linfo[0][0].m_frameLengthInBits;
}

int CLatmDemux_GetOtherDataPresentFlag(CLatmDemux *pLatmDemux)
{
  return pLatmDemux->m_otherDataPresent ? 1 : 0;
}

int CLatmDemux_GetOtherDataLength(CLatmDemux *pLatmDemux)
{
  return pLatmDemux->m_otherDataLength;
}

UINT CLatmDemux_GetNrOfSubFrames(CLatmDemux *pLatmDemux)
{
  return pLatmDemux->m_noSubFrames;
}

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