Пример #1
0
int CProgramConfig_GetElementTable(
        const CProgramConfig *pPce,
        MP4_ELEMENT_ID  elList[],
        const INT elListSize,
        UCHAR *pChMapIdx
       )
{
  int i, el = 0;

  FDK_ASSERT(elList != NULL);
  FDK_ASSERT(pChMapIdx != NULL);

  *pChMapIdx = 0;

  if ( elListSize
    < pPce->NumFrontChannelElements + pPce->NumSideChannelElements + pPce->NumBackChannelElements + pPce->NumLfeChannelElements
    )
  {
    return 0;
  }

  for (i=0; i < pPce->NumFrontChannelElements; i++)
  {
    elList[el++] = (pPce->FrontElementIsCpe[i]) ?  ID_CPE : ID_SCE;
  }

  for (i=0; i < pPce->NumSideChannelElements; i++)
  {
    elList[el++] = (pPce->SideElementIsCpe[i]) ?  ID_CPE : ID_SCE;
  }

  for (i=0; i < pPce->NumBackChannelElements; i++)
  {
    elList[el++] = (pPce->BackElementIsCpe[i]) ?  ID_CPE : ID_SCE;
  }

  for (i=0; i < pPce->NumLfeChannelElements; i++)
  {
    elList[el++] = ID_LFE;
  }


  /* Find an corresponding channel configuration if possible */
  switch (pPce->NumChannels) {
  case 1: case 2: case 3: case 4: case 5: case 6:
    /* One and two channels have no alternatives. The other ones are mapped directly to the
       corresponding channel config. Because of legacy reasons or for lack of alternative mappings. */
    *pChMapIdx = pPce->NumChannels;
    break;
  case 7:
    {
      C_ALLOC_SCRATCH_START(tmpPce, CProgramConfig, 1);
      /* Create a PCE for the config to test ... */
      CProgramConfig_GetDefault(tmpPce, 11);
      /* ... and compare it with the given one. */
      *pChMapIdx = (!(CProgramConfig_Compare(pPce, tmpPce)&0xE)) ? 11 : 0;
      /* If compare result is 0 or 1 we can be sure that it is channel config 11. */
      C_ALLOC_SCRATCH_END(tmpPce, CProgramConfig, 1);
    }
    break;
  case 8:
    { /* Try the four possible 7.1ch configurations. One after the other. */
      UCHAR testCfg[4] = { 32, 14, 12, 7};
      C_ALLOC_SCRATCH_START(tmpPce, CProgramConfig, 1);
      for (i=0; i<4; i+=1) {
        /* Create a PCE for the config to test ... */
        CProgramConfig_GetDefault(tmpPce, testCfg[i]);
        /* ... and compare it with the given one. */
        if (!(CProgramConfig_Compare(pPce, tmpPce)&0xE)) {
          /* If the compare result is 0 or 1 than the two channel configurations match. */
          /* Explicit mapping of 7.1 side channel configuration to 7.1 rear channel mapping. */
          *pChMapIdx = (testCfg[i]==32) ? 12 : testCfg[i];
        }
      }
      C_ALLOC_SCRATCH_END(tmpPce, CProgramConfig, 1);
    }
    break;
  default:
    /* The PCE does not match any predefined channel configuration. */
    *pChMapIdx = 0;
    break;
  }

  return el;
}
Пример #2
0
static
TRANSPORTDEC_ERROR synchronization(
        HANDLE_TRANSPORTDEC hTp,
        INT                *pHeaderBits
        )
{
  TRANSPORTDEC_ERROR err = TRANSPORTDEC_OK, errFirstFrame = TRANSPORTDEC_OK;
  HANDLE_FDK_BITSTREAM hBs = &hTp->bitStream[0];

  INT syncLayerFrameBits = 0; /* Length of sync layer frame (i.e. LOAS) */
  INT rawDataBlockLength = 0, rawDataBlockLengthPrevious;
  INT totalBits;
  INT headerBits = 0, headerBitsFirstFrame = 0, headerBitsPrevious;
  INT numFramesTraversed = 0, fTraverseMoreFrames, fConfigFound = 0, startPos, startPosFirstFrame = -1;
  INT numRawDataBlocksFirstFrame = 0, numRawDataBlocksPrevious, globalFramePosFirstFrame = 0, rawDataBlockLengthFirstFrame = 0;
  INT ignoreBufferFullness = hTp->flags & (TPDEC_IGNORE_BUFFERFULLNESS|TPDEC_SYNCOK);

  /* Synch parameters */
  INT syncLength;      /* Length of sync word in bits */
  UINT syncWord;       /* Sync word to be found */
  UINT syncMask;       /* Mask for sync word (for adding one bit, so comprising one bit less) */
  C_ALLOC_SCRATCH_START(contextFirstFrame, transportdec_parser_t, 1);

  totalBits = (INT)FDKgetValidBits(hBs);

  if (totalBits <= 0) {
    /* Return sync error, because this happens only in case of severly damaged bit streams.
       Returning TRANSPORTDEC_NOT_ENOUGH_BITS here is very dangerous. */
    /* numberOfRawDataBlocks must be always reset in case of sync errors. */
    hTp->numberOfRawDataBlocks = 0;
    goto bail;
  }

  fTraverseMoreFrames = (hTp->flags & (TPDEC_MINIMIZE_DELAY|TPDEC_EARLY_CONFIG)) && ! (hTp->flags & TPDEC_SYNCOK);

  /* Set transport specific sync parameters */
  switch (hTp->transportFmt) {
    case TT_MP4_ADTS:
      syncWord = ADTS_SYNCWORD;
      syncLength = ADTS_SYNCLENGTH;
      break;
    case TT_MP4_LOAS:
      syncWord = 0x2B7;
      syncLength = 11;
      break;
    default:
      syncWord = 0;
      syncLength = 0;
      break;
  }

  syncMask = (1<<syncLength)-1;

  do {
    INT bitsAvail = 0;     /* Bits available in bitstream buffer    */
    INT checkLengthBits;   /* Helper to check remaining bits and buffer boundaries */
    UINT synch;            /* Current sync word read from bitstream */

    headerBitsPrevious = headerBits;

    bitsAvail = (INT)FDKgetValidBits(hBs);

    if (hTp->numberOfRawDataBlocks == 0) {
      /* search synchword */

      FDK_ASSERT( (bitsAvail % TPDEC_SYNCSKIP) == 0);

      if ((bitsAvail-syncLength) < TPDEC_SYNCSKIP) {
        err = TRANSPORTDEC_NOT_ENOUGH_BITS;
        headerBits = 0;
      } else {

        synch = FDKreadBits(hBs, syncLength);

        if ( !(hTp->flags & TPDEC_SYNCOK) ) {
          for (; (bitsAvail-syncLength) >= TPDEC_SYNCSKIP; bitsAvail-=TPDEC_SYNCSKIP) {
            if (synch == syncWord) {
              break;
            }
            synch = ((synch << TPDEC_SYNCSKIP) & syncMask) | FDKreadBits(hBs, TPDEC_SYNCSKIP);
          }
        }
        if (synch != syncWord) {
          /* No correct syncword found. */
          err = TRANSPORTDEC_SYNC_ERROR;
        } else {
          err = TRANSPORTDEC_OK;
        }
        headerBits = syncLength;
      }
    } else {
      headerBits = 0;
    }

    /* Save previous raw data block data */
    rawDataBlockLengthPrevious = rawDataBlockLength;
    numRawDataBlocksPrevious = hTp->numberOfRawDataBlocks;

    /* Parse transport header (raw data block granularity) */
    startPos = FDKgetValidBits(hBs);

    if (err == TRANSPORTDEC_OK )
    {
      switch (hTp->transportFmt) {
        case TT_MP4_ADTS:
          if (hTp->numberOfRawDataBlocks <= 0)
          {
            int errC;

            /* Parse ADTS header */
            err = adtsRead_DecodeHeader( &hTp->parser.adts, &hTp->asc[0], hBs, ignoreBufferFullness );
            if (err != TRANSPORTDEC_OK) {
              if (err != TRANSPORTDEC_NOT_ENOUGH_BITS) {
                err = TRANSPORTDEC_SYNC_ERROR;
              }
            } else {
              errC = hTp->callbacks.cbUpdateConfig(hTp->callbacks.cbUpdateConfigData, &hTp->asc[0]);
              if (errC != 0) {
                err = TRANSPORTDEC_SYNC_ERROR;
              } else {
                hTp->numberOfRawDataBlocks = hTp->parser.adts.bs.num_raw_blocks+1;
                /* CAUTION: The PCE (if available) is declared to be a part of the header! */
                hTp->globalFramePos = FDKgetValidBits(hBs) + hTp->parser.adts.bs.num_pce_bits;
              }
            }
          }
          else {
            /* Reset CRC because the next bits are the beginning of a raw_data_block() */
            FDKcrcReset(&hTp->parser.adts.crcInfo);
            hTp->globalFramePos = FDKgetValidBits(hBs);
          }
          if (err == TRANSPORTDEC_OK) {
            hTp->numberOfRawDataBlocks--;
            rawDataBlockLength = adtsRead_GetRawDataBlockLength(&hTp->parser.adts, (hTp->parser.adts.bs.num_raw_blocks-hTp->numberOfRawDataBlocks));
            syncLayerFrameBits = (hTp->parser.adts.bs.frame_length<<3) - (startPos - FDKgetValidBits(hBs)) - syncLength;
            if (syncLayerFrameBits <= 0) {
              err = TRANSPORTDEC_SYNC_ERROR;
            }
          } else {
            hTp->numberOfRawDataBlocks = 0;
          }
          break;
        case TT_MP4_LOAS:
          if (hTp->numberOfRawDataBlocks <= 0)
          {
            syncLayerFrameBits = FDKreadBits(hBs, 13);
            hTp->parser.latm.m_audioMuxLengthBytes = syncLayerFrameBits;
            syncLayerFrameBits <<= 3;
          }
        case TT_MP4_LATM_MCP1:
        case TT_MP4_LATM_MCP0:
          if (hTp->numberOfRawDataBlocks <= 0)
          {
            hTp->globalFramePos = FDKgetValidBits(hBs);

            err = CLatmDemux_Read(
                    hBs,
                   &hTp->parser.latm,
                    hTp->transportFmt,
                   &hTp->callbacks,
                    hTp->asc,
                    ignoreBufferFullness);

            if (err != TRANSPORTDEC_OK) {
              if (err != TRANSPORTDEC_NOT_ENOUGH_BITS) {
                err = TRANSPORTDEC_SYNC_ERROR;
              }
            } else {
              hTp->numberOfRawDataBlocks = CLatmDemux_GetNrOfSubFrames(&hTp->parser.latm);
              syncLayerFrameBits -= startPos - FDKgetValidBits(hBs) - (13);            
            }
          } else {
            err = CLatmDemux_ReadPayloadLengthInfo(hBs, &hTp->parser.latm);
            if (err != TRANSPORTDEC_OK) {
              err = TRANSPORTDEC_SYNC_ERROR;
            }
          }
          if (err == TRANSPORTDEC_OK) {
            rawDataBlockLength = CLatmDemux_GetFrameLengthInBits(&hTp->parser.latm);
            hTp->numberOfRawDataBlocks--;
          } else {
            hTp->numberOfRawDataBlocks = 0;
          }
          break;
        default:
          {
            syncLayerFrameBits = 0;
          }
          break;
      }
    }

    headerBits += startPos - (INT)FDKgetValidBits(hBs);
    bitsAvail -= headerBits;

    checkLengthBits  = syncLayerFrameBits;

    /* Check if the whole frame would fit the bitstream buffer */
    if (err == TRANSPORTDEC_OK) {
      if ( (checkLengthBits+headerBits) > ((TRANSPORTDEC_INBUF_SIZE<<3)-7) ) {
        /* We assume that the size of the transport bit buffer has been
           chosen to meet all system requirements, thus this condition
           is considered a synchronisation error. */
        err = TRANSPORTDEC_SYNC_ERROR;
      } else {
        if ( bitsAvail < checkLengthBits ) {
          err = TRANSPORTDEC_NOT_ENOUGH_BITS;
        }
      }
    }

    if (err == TRANSPORTDEC_NOT_ENOUGH_BITS) {
      break;
    }


    if (err == TRANSPORTDEC_SYNC_ERROR) {
      int bits;

      /* Enforce re-sync of transport headers. */
      hTp->numberOfRawDataBlocks = 0;

      /* Ensure that the bit amount lands and a multiple of TPDEC_SYNCSKIP */
      bits = (bitsAvail + headerBits) % TPDEC_SYNCSKIP;
      /* Rewind - TPDEC_SYNCSKIP, in order to look for a synch one bit ahead next time. */
      FDKpushBiDirectional(hBs, -(headerBits - TPDEC_SYNCSKIP) + bits);
      bitsAvail += headerBits - TPDEC_SYNCSKIP - bits;
      headerBits = 0;      
    }

    /* Frame traversal */
    if ( fTraverseMoreFrames )
    {
      /* Save parser context for early config discovery "rewind all frames" */
      if ( (hTp->flags & TPDEC_EARLY_CONFIG) && !(hTp->flags & TPDEC_MINIMIZE_DELAY))
      {
        /* ignore buffer fullness if just traversing additional frames for ECD */
        ignoreBufferFullness = 1;

        /* Save context in order to return later */
        if ( err == TRANSPORTDEC_OK && startPosFirstFrame == -1 ) {
          startPosFirstFrame = FDKgetValidBits(hBs);
          numRawDataBlocksFirstFrame = hTp->numberOfRawDataBlocks;
          globalFramePosFirstFrame = hTp->globalFramePos;
          rawDataBlockLengthFirstFrame = rawDataBlockLength;
          headerBitsFirstFrame = headerBits;
          errFirstFrame = err;
          FDKmemcpy(contextFirstFrame, &hTp->parser, sizeof(transportdec_parser_t));
        }

        /* Break when config was found or it is not possible anymore to find a config */
        if (startPosFirstFrame != -1 && (fConfigFound || err != TRANSPORTDEC_OK)) {
          break;
        }
      }

      if (err == TRANSPORTDEC_OK) {
        FDKpushFor(hBs, rawDataBlockLength);
        bitsAvail -= rawDataBlockLength;
        numFramesTraversed++;
        /* Ignore error here itentionally. */
        transportDec_AdjustEndOfAccessUnit(hTp);
      }
    }
  } while ( fTraverseMoreFrames || (err == TRANSPORTDEC_SYNC_ERROR && !(hTp->flags & TPDEC_SYNCOK)));

  /* Restore context in case of ECD frame traversal */
  if ( startPosFirstFrame != -1 && (fConfigFound || err != TRANSPORTDEC_OK) ) {
    FDKpushBiDirectional(hBs, FDKgetValidBits(hBs) - startPosFirstFrame);
    FDKmemcpy(&hTp->parser, contextFirstFrame, sizeof(transportdec_parser_t));
    hTp->numberOfRawDataBlocks = numRawDataBlocksFirstFrame;
    hTp->globalFramePos = globalFramePosFirstFrame;
    rawDataBlockLength = rawDataBlockLengthFirstFrame;
    headerBits = headerBitsFirstFrame;
    err = errFirstFrame;
    numFramesTraversed = 0;
  } 

  /* Additional burst data mode buffer fullness check. */
  if ( !(hTp->flags & (TPDEC_IGNORE_BUFFERFULLNESS|TPDEC_SYNCOK)) && err == TRANSPORTDEC_OK) {
    err = additionalHoldOffNeeded(hTp, transportDec_GetBufferFullness(hTp), FDKgetValidBits(hBs) - syncLayerFrameBits);
    if (err == TRANSPORTDEC_NOT_ENOUGH_BITS) {
      hTp->holdOffFrames++;
    }
  }
  
  /* Rewind for retry because of not enough bits */
  if (err == TRANSPORTDEC_NOT_ENOUGH_BITS) {
    FDKpushBack(hBs, headerBits);
    headerBits = 0;
  }
  else {
    /* reset hold off frame counter */
    hTp->holdOffFrames = 0;
  }

  /* Return to last good frame in case of frame traversal but not ECD. */
  if (numFramesTraversed > 0) {
    FDKpushBack(hBs, rawDataBlockLengthPrevious);
    if (err != TRANSPORTDEC_OK) {
      hTp->numberOfRawDataBlocks = numRawDataBlocksPrevious;
      headerBits = headerBitsPrevious;
    }
    err = TRANSPORTDEC_OK;
  }

bail:
  hTp->auLength[0] = rawDataBlockLength;

  if (err == TRANSPORTDEC_OK) {
    hTp->flags |= TPDEC_SYNCOK;
  }

  if (pHeaderBits != NULL) {
    *pHeaderBits = headerBits;
  }

  if (err == TRANSPORTDEC_SYNC_ERROR) {
    hTp->flags &= ~TPDEC_SYNCOK;
  }

  C_ALLOC_SCRATCH_END(contextFirstFrame, transportdec_parser_t, 1);

  return err;
}
Пример #3
0
static
TRANSPORTDEC_ERROR synchronization(
        HANDLE_TRANSPORTDEC hTp,
        INT                *pHeaderBits
        )
{
  TRANSPORTDEC_ERROR err = TRANSPORTDEC_OK, errFirstFrame = TRANSPORTDEC_OK;
  HANDLE_FDK_BITSTREAM hBs = &hTp->bitStream[0];

  INT syncLayerFrameBits = 0; /* Length of sync layer frame (i.e. LOAS) */
  INT rawDataBlockLength = 0, rawDataBlockLengthPrevious;
  INT totalBits;
  INT headerBits = 0, headerBitsFirstFrame = 0, headerBitsPrevious;
  INT numFramesTraversed = 0, fTraverseMoreFrames, fConfigFound = (hTp->flags & TPDEC_CONFIG_FOUND), startPosFirstFrame = -1;
  INT numRawDataBlocksFirstFrame = 0, numRawDataBlocksPrevious, globalFramePosFirstFrame = 0, rawDataBlockLengthFirstFrame = 0;
  INT ignoreBufferFullness = hTp->flags & (TPDEC_LOST_FRAMES_PENDING|TPDEC_IGNORE_BUFFERFULLNESS|TPDEC_SYNCOK);

  /* Synch parameters */
  INT syncLength;      /* Length of sync word in bits */
  UINT syncWord;       /* Sync word to be found */
  UINT syncMask;       /* Mask for sync word (for adding one bit, so comprising one bit less) */
  C_ALLOC_SCRATCH_START(contextFirstFrame, transportdec_parser_t, 1);

  totalBits = (INT)FDKgetValidBits(hBs);

  if (totalBits <= 0) {
    err = TRANSPORTDEC_NOT_ENOUGH_BITS;
    goto bail;
  }

  fTraverseMoreFrames = (hTp->flags & (TPDEC_MINIMIZE_DELAY|TPDEC_EARLY_CONFIG)) && ! (hTp->flags & TPDEC_SYNCOK);

  /* Set transport specific sync parameters */
  switch (hTp->transportFmt) {
    case TT_MP4_ADTS:
      syncWord = ADTS_SYNCWORD;
      syncLength = ADTS_SYNCLENGTH;
      break;
    case TT_MP4_LOAS:
      syncWord = 0x2B7;
      syncLength = 11;
      break;
    default:
      syncWord = 0;
      syncLength = 0;
      break;
  }

  syncMask = (1<<syncLength)-1;

  do {
    INT bitsAvail = 0;     /* Bits available in bitstream buffer    */
    INT checkLengthBits;   /* Helper to check remaining bits and buffer boundaries */
    UINT synch;            /* Current sync word read from bitstream */

    headerBitsPrevious = headerBits;

    bitsAvail = (INT)FDKgetValidBits(hBs);

    if (hTp->numberOfRawDataBlocks == 0) {
      /* search synchword */

      FDK_ASSERT( (bitsAvail % TPDEC_SYNCSKIP) == 0);

      if ((bitsAvail-syncLength) < TPDEC_SYNCSKIP) {
        err = TRANSPORTDEC_NOT_ENOUGH_BITS;
        headerBits = 0;
      } else {

        synch = FDKreadBits(hBs, syncLength);

        if ( !(hTp->flags & TPDEC_SYNCOK) ) {
          for (; (bitsAvail-syncLength) >= TPDEC_SYNCSKIP; bitsAvail-=TPDEC_SYNCSKIP) {
            if (synch == syncWord) {
              break;
            }
            synch = ((synch << TPDEC_SYNCSKIP) & syncMask) | FDKreadBits(hBs, TPDEC_SYNCSKIP);
          }
        }
        if (synch != syncWord) {
          /* No correct syncword found. */
          err = TRANSPORTDEC_SYNC_ERROR;
        } else {
          err = TRANSPORTDEC_OK;
        }
        headerBits = syncLength;
      }
    } else {
      headerBits = 0;
    }

    /* Save previous raw data block data */
    rawDataBlockLengthPrevious = rawDataBlockLength;
    numRawDataBlocksPrevious = hTp->numberOfRawDataBlocks;

    /* Parse transport header (raw data block granularity) */

    if (err == TRANSPORTDEC_OK )
    {
      err = transportDec_readHeader(
              hTp,
              hBs,
              syncLength,
              ignoreBufferFullness,
             &rawDataBlockLength,
             &fTraverseMoreFrames,
             &syncLayerFrameBits,
             &fConfigFound,
             &headerBits
              );
    }

    bitsAvail -= headerBits;

    checkLengthBits  = syncLayerFrameBits;

    /* Check if the whole frame would fit the bitstream buffer */
    if (err == TRANSPORTDEC_OK) {
      if ( (checkLengthBits+headerBits) > ((TRANSPORTDEC_INBUF_SIZE<<3)-7) ) {
        /* We assume that the size of the transport bit buffer has been
           chosen to meet all system requirements, thus this condition
           is considered a synchronisation error. */
        err = TRANSPORTDEC_SYNC_ERROR;
      } else {
        if ( bitsAvail < checkLengthBits ) {
          err = TRANSPORTDEC_NOT_ENOUGH_BITS;
        }
      }
    }

    if (err == TRANSPORTDEC_NOT_ENOUGH_BITS) {
      break;
    }


    if (err == TRANSPORTDEC_SYNC_ERROR) {
      int bits;

      /* Enforce re-sync of transport headers. */
      hTp->numberOfRawDataBlocks = 0;

      /* Ensure that the bit amount lands at a multiple of TPDEC_SYNCSKIP */
      bits = (bitsAvail + headerBits) % TPDEC_SYNCSKIP;
      /* Rewind - TPDEC_SYNCSKIP, in order to look for a synch one bit ahead next time. */
      FDKpushBiDirectional(hBs, -(headerBits - TPDEC_SYNCSKIP) + bits);
      bitsAvail += headerBits - TPDEC_SYNCSKIP - bits;
      headerBits = 0;
    }

    /* Frame traversal */
    if ( fTraverseMoreFrames )
    {
      /* Save parser context for early config discovery "rewind all frames" */
      if ( (hTp->flags & TPDEC_EARLY_CONFIG) && !(hTp->flags & TPDEC_MINIMIZE_DELAY))
      {
        /* ignore buffer fullness if just traversing additional frames for ECD */
        ignoreBufferFullness = 1;

        /* Save context in order to return later */
        if ( err == TRANSPORTDEC_OK && startPosFirstFrame == -1 ) {
          startPosFirstFrame = FDKgetValidBits(hBs);
          numRawDataBlocksFirstFrame = hTp->numberOfRawDataBlocks;
          globalFramePosFirstFrame = hTp->globalFramePos;
          rawDataBlockLengthFirstFrame = rawDataBlockLength;
          headerBitsFirstFrame = headerBits;
          errFirstFrame = err;
          FDKmemcpy(contextFirstFrame, &hTp->parser, sizeof(transportdec_parser_t));
        }

        /* Break when config was found or it is not possible anymore to find a config */
        if (startPosFirstFrame != -1 && (fConfigFound || err != TRANSPORTDEC_OK))
        {
          /* In case of ECD and sync error, do not rewind anywhere. */
          if (err == TRANSPORTDEC_SYNC_ERROR)
          {
            startPosFirstFrame = -1;
            fConfigFound = 0;
            numFramesTraversed = 0;
          }
          break;
        }
      }

      if (err == TRANSPORTDEC_OK) {
        FDKpushFor(hBs, rawDataBlockLength);
        bitsAvail -= rawDataBlockLength;
        numFramesTraversed++;
        /* Ignore error here itentionally. */
        transportDec_AdjustEndOfAccessUnit(hTp);
      }
    }
  } while ( fTraverseMoreFrames || (err == TRANSPORTDEC_SYNC_ERROR && !(hTp->flags & TPDEC_SYNCOK)));

  /* Restore context in case of ECD frame traversal */
  if ( startPosFirstFrame != -1 && (fConfigFound || err != TRANSPORTDEC_OK) ) {
    FDKpushBiDirectional(hBs, FDKgetValidBits(hBs) - startPosFirstFrame);
    FDKmemcpy(&hTp->parser, contextFirstFrame, sizeof(transportdec_parser_t));
    hTp->numberOfRawDataBlocks = numRawDataBlocksFirstFrame;
    hTp->globalFramePos = globalFramePosFirstFrame;
    rawDataBlockLength = rawDataBlockLengthFirstFrame;
    headerBits = headerBitsFirstFrame;
    err = errFirstFrame;
    numFramesTraversed = 0;
  } 

  /* Additional burst data mode buffer fullness check. */
  if ( !(hTp->flags & (TPDEC_LOST_FRAMES_PENDING|TPDEC_IGNORE_BUFFERFULLNESS|TPDEC_SYNCOK)) && err == TRANSPORTDEC_OK) {
    err = additionalHoldOffNeeded(hTp, transportDec_GetBufferFullness(hTp), FDKgetValidBits(hBs) - syncLayerFrameBits);
    if (err == TRANSPORTDEC_NOT_ENOUGH_BITS) {
      hTp->holdOffFrames++;
    }
  }
  
  /* Rewind for retry because of not enough bits */
  if (err == TRANSPORTDEC_NOT_ENOUGH_BITS) {
    FDKpushBack(hBs, headerBits);
    headerBits = 0;
  }
  else {
    /* reset hold off frame counter */
    hTp->holdOffFrames = 0;
  }

  /* Return to last good frame in case of frame traversal but not ECD. */
  if (numFramesTraversed > 0) {
    FDKpushBack(hBs, rawDataBlockLengthPrevious);
    if (err != TRANSPORTDEC_OK) {
      hTp->numberOfRawDataBlocks = numRawDataBlocksPrevious;
      headerBits = headerBitsPrevious;
    }
    err = TRANSPORTDEC_OK;
  }

bail:
  hTp->auLength[0] = rawDataBlockLength;

  /* Detect pointless TRANSPORTDEC_NOT_ENOUGH_BITS error case, were the bit buffer is already full,
     or no new burst packet fits. Recover by advancing the bit buffer. */
  if ( (TRANSPORTDEC_NOT_ENOUGH_BITS == err) &&  (FDKgetValidBits(hBs) >= ((TRANSPORTDEC_INBUF_SIZE*8 - ((hTp->avgBitRate*hTp->burstPeriod)/1000)) - 7)) )
  {
    FDKpushFor(hBs, TPDEC_SYNCSKIP);
    err = TRANSPORTDEC_SYNC_ERROR;
  }

  if (err == TRANSPORTDEC_OK) {
    hTp->flags |= TPDEC_SYNCOK;
  }

  if (fConfigFound) {
    hTp->flags |= TPDEC_CONFIG_FOUND;
  }

  if (pHeaderBits != NULL) {
    *pHeaderBits = headerBits;
  }

  if (err == TRANSPORTDEC_SYNC_ERROR) {
    hTp->flags &= ~TPDEC_SYNCOK;
  }

  C_ALLOC_SCRATCH_END(contextFirstFrame, transportdec_parser_t, 1);

  return err;
}