path: root/libMpegTPDec/src/tpdec_asc.cpp

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

                        (C) Copyright Fraunhofer IIS (2004)
                               All Rights Reserved

    Please be advised that this software and/or program delivery is
    Confidential Information of Fraunhofer and subject to and covered by the

    Fraunhofer IIS Software Evaluation Agreement
    between Google Inc. and  Fraunhofer
    effective and in full force since March 1, 2012.

    You may use this software and/or program only under the terms and
    conditions described in the above mentioned Fraunhofer IIS Software
    Evaluation Agreement. Any other and/or further use requires a separate agreement.


   $Id$
   Author(s):   Daniel Homm
   Description:

   This software and/or program is protected by copyright law and international
   treaties. Any reproduction or distribution of this software and/or program,
   or any portion of it, may result in severe civil and criminal penalties, and
   will be prosecuted to the maximum extent possible under law.

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

#include "tpdec_lib.h"
#include "tp_data.h"


void CProgramConfig_Reset(CProgramConfig *pPce)
{
  pPce->elCounter = 0;
}

void CProgramConfig_Init(CProgramConfig *pPce)
{
  FDKmemclear(pPce, sizeof(CProgramConfig));
#ifdef TP_PCE_ENABLE
  pPce->SamplingFrequencyIndex = 0xf;
#endif
}

int  CProgramConfig_IsValid ( const CProgramConfig *pPce )
{
  return ( (pPce->isValid) ? 1 : 0);
}

#ifdef TP_PCE_ENABLE
void CProgramConfig_Read(
                          CProgramConfig *pPce,
                          HANDLE_FDK_BITSTREAM bs,
                          UINT alignmentAnchor
                        )
{
  int i;

  pPce->NumEffectiveChannels = 0;
  pPce->NumChannels = 0;
  pPce->ElementInstanceTag = (UCHAR) FDKreadBits(bs,4);
  pPce->Profile = (UCHAR) FDKreadBits(bs,2);
  pPce->SamplingFrequencyIndex = (UCHAR) FDKreadBits(bs,4);
  pPce->NumFrontChannelElements = (UCHAR) FDKreadBits(bs,4);
  pPce->NumSideChannelElements = (UCHAR) FDKreadBits(bs,4);
  pPce->NumBackChannelElements = (UCHAR) FDKreadBits(bs,4);
  pPce->NumLfeChannelElements = (UCHAR) FDKreadBits(bs,2);
  pPce->NumAssocDataElements = (UCHAR) FDKreadBits(bs,3);
  pPce->NumValidCcElements = (UCHAR) FDKreadBits(bs,4);

  if ((pPce->MonoMixdownPresent = (UCHAR) FDKreadBits(bs,1)) != 0)
  {
    pPce->MonoMixdownElementNumber = (UCHAR) FDKreadBits(bs,4);
  }

  if ((pPce->StereoMixdownPresent = (UCHAR) FDKreadBits(bs,1)) != 0)
  {
    pPce->StereoMixdownElementNumber = (UCHAR) FDKreadBits(bs,4);
  }

  if ((pPce->MatrixMixdownIndexPresent = (UCHAR) FDKreadBits(bs,1)) != 0)
  {
    pPce->MatrixMixdownIndex = (UCHAR) FDKreadBits(bs,2);
    pPce->PseudoSurroundEnable = (UCHAR) FDKreadBits(bs,1);
  }

  for (i=0; i < pPce->NumFrontChannelElements; i++)
  {
    pPce->FrontElementIsCpe[i] = (UCHAR) FDKreadBits(bs,1);
    pPce->FrontElementTagSelect[i] = (UCHAR) FDKreadBits(bs,4);
    pPce->NumChannels += pPce->FrontElementIsCpe[i] ? 2 : 1;
  }

  for (i=0; i < pPce->NumSideChannelElements; i++)
  {
    pPce->SideElementIsCpe[i] = (UCHAR) FDKreadBits(bs,1);
    pPce->SideElementTagSelect[i] = (UCHAR) FDKreadBits(bs,4);
    pPce->NumChannels += pPce->SideElementIsCpe[i] ? 2 : 1;
  }

  for (i=0; i < pPce->NumBackChannelElements; i++)
  {
    pPce->BackElementIsCpe[i] = (UCHAR) FDKreadBits(bs,1);
    pPce->BackElementTagSelect[i] = (UCHAR) FDKreadBits(bs,4);
    pPce->NumChannels += pPce->BackElementIsCpe[i] ? 2 : 1;
  }

  pPce->NumEffectiveChannels = pPce->NumChannels;

  for (i=0; i < pPce->NumLfeChannelElements; i++)
  {
    pPce->LfeElementTagSelect[i] = (UCHAR) FDKreadBits(bs,4);
    pPce->NumChannels += 1;
  }

  for (i=0; i < pPce->NumAssocDataElements; i++)
  {
    pPce->AssocDataElementTagSelect[i] = (UCHAR) FDKreadBits(bs,4);
  }

  for (i=0; i < pPce->NumValidCcElements; i++)
  {
    pPce->CcElementIsIndSw[i] = (UCHAR) FDKreadBits(bs,1);
    pPce->ValidCcElementTagSelect[i] = (UCHAR) FDKreadBits(bs,4);
  }

  FDKbyteAlign(bs, alignmentAnchor);

  pPce->CommentFieldBytes = (UCHAR) FDKreadBits(bs,8);

  for (i=0; i < pPce->CommentFieldBytes; i++)
  {
    UCHAR text;

    text = (UCHAR)FDKreadBits(bs,8);

    if (i < PC_COMMENTLENGTH)
    {
      pPce->Comment[i] = text;
    }
  }

  pPce->isValid = 1;
}
#endif /* TP_PCE_ENABLE */

/**
 * \brief get implicit audio channel type for given channelConfig and MPEG ordered channel index
 * \param channelConfig MPEG channelConfiguration from 1 upto 7
 * \param index MPEG channel order index
 * \return audio channel type.
 */
void getImplicitAudioChannelTypeAndIndex(
        AUDIO_CHANNEL_TYPE *chType,
        UCHAR *chIndex,
        UINT channelConfig,
        UINT index
        )
{
  if (index < 3) {
    *chType = ACT_FRONT;
    *chIndex = index;
  } else {
    switch (channelConfig) {
      case MODE_1_2_1:
      case MODE_1_2_2:
      case MODE_1_2_2_1:
        switch (index) {
          case 3:
          case 4:
            *chType = ACT_BACK;
            *chIndex = index - 3;
            break;
          case 5:
            *chType = ACT_LFE;
            *chIndex = 0;
            break;
        }
        break;
      case MODE_1_2_2_2_1:
        switch (index) {
          case 3:
          case 4:
            *chType = ACT_SIDE;
            *chIndex = index - 3;
            break;
          case 5:
          case 6:
            *chType = ACT_BACK;
            *chIndex = index - 5;
            break;
          case 7:
            *chType = ACT_LFE;
            *chIndex = 0;
            break;
        }
        break;
      default:
        *chType = ACT_NONE;
        break;
    }
  }
}

int CProgramConfig_LookupElement(
        CProgramConfig *pPce,
        const UINT      channelConfig,
        const UINT      tag,
        const UINT      channelIdx,
        UCHAR           chMapping[],
        AUDIO_CHANNEL_TYPE chType[],
        UCHAR           chIndex[],
        UCHAR          *elMapping,
        MP4_ELEMENT_ID  elList[],
        MP4_ELEMENT_ID  elType
       )
{
  if (channelConfig > 0)
  {
    /* Constant channel mapping must have
       been set during initialization. */
    if ( elType == ID_SCE
      || elType == ID_CPE
      || elType == ID_LFE )
    {
      *elMapping = pPce->elCounter;
      if (elList[pPce->elCounter] != elType) {
        /* Not in the list */
        return 0;
      }
      /* Assume all front channels */
      getImplicitAudioChannelTypeAndIndex(&chType[channelIdx], &chIndex[channelIdx], channelConfig, channelIdx);
      if (elType == ID_CPE) {
        chType[channelIdx+1] = chType[channelIdx];
        chIndex[channelIdx+1] = chIndex[channelIdx]+1;
      }
      pPce->elCounter++;
    }
    /* Accept all non-channel elements, too. */
    return 1;
  }
  else
  {
#ifdef TP_PCE_ENABLE
    if (!pPce->isValid)
#endif /* TP_PCE_ENABLE */
    {
      /* Implicit channel mapping. */
      if ( elType == ID_SCE
        || elType == ID_CPE
        || elType == ID_LFE )
      {
        /* Store all channel element IDs */
        elList[pPce->elCounter] = elType;
        *elMapping = pPce->elCounter++;
      }
    }
#ifdef  TP_PCE_ENABLE
    else {
      /* Accept the additional channel(s), only if the tag is in the lists */
      int isCpe = 0, i;
      int cc = 0, fc = 0, sc = 0, bc = 0, lc = 0, ec = 0; /* Channel and element counters */

      switch (elType)
      {
      case ID_CPE:
        isCpe = 1;
      case ID_SCE:
        /* search in front channels */
        for (i = 0; i < pPce->NumFrontChannelElements; i++) {
          if (isCpe == pPce->FrontElementIsCpe[i] && pPce->FrontElementTagSelect[i] == tag) {
            chMapping[cc] = channelIdx;
            chType[cc] = ACT_FRONT;
            chIndex[cc] = fc;
            if (isCpe) {
              chMapping[cc+1] = channelIdx+1;
              chType[cc+1] = ACT_FRONT;
              chIndex[cc+1] = fc+1;
            }
            *elMapping = ec;
            return 1;
          }
          ec++;
          if (pPce->FrontElementIsCpe[i]) {
            cc+=2; fc+=2;
          } else {
            cc++; fc++;
          }
        }
        /* search in side channels */
        for (i = 0; i < pPce->NumSideChannelElements; i++) {
          if (isCpe == pPce->SideElementIsCpe[i] && pPce->SideElementTagSelect[i] == tag) {
            chMapping[cc] = channelIdx;
            chType[cc] = ACT_SIDE;
            chIndex[cc] = sc;
            if (isCpe) {
              chMapping[cc+1] = channelIdx+1;
              chType[cc+1] = ACT_SIDE;
              chIndex[cc+1] = sc+1;
            }
            *elMapping = ec;
            return 1;
          }
          ec++;
          if (pPce->SideElementIsCpe[i]) {
            cc+=2; sc+=2;
          } else {
            cc++; sc++;
          }
        }
        /* search in back channels */
        for (i = 0; i < pPce->NumBackChannelElements; i++) {
          if (isCpe == pPce->BackElementIsCpe[i] && pPce->BackElementTagSelect[i] == tag) {
            chMapping[cc] = channelIdx;
            chType[cc] = ACT_BACK;
            chIndex[cc] = bc;
            if (isCpe) {
              chMapping[cc+1] = channelIdx+1;
              chType[cc+1] = ACT_BACK;
              chIndex[cc+1] = bc+1;
            }
            *elMapping = ec;
            return 1;
          }
          ec++;
          if (pPce->BackElementIsCpe[i]) {
            cc+=2; bc+=2;
          } else {
            cc++; bc++;
          }
        }
        break;

      case ID_LFE:
        /* Initialize channel counter and element counter */
        cc = pPce->NumEffectiveChannels;
        ec = pPce->NumFrontChannelElements+ pPce->NumSideChannelElements + pPce->NumBackChannelElements;
        /* search in lfe channels */
        for (i = 0; i < pPce->NumLfeChannelElements; i++) {
          if ( pPce->LfeElementTagSelect[i] == tag ) {
            chMapping[cc] = channelIdx;
            *elMapping = ec;
            chType[cc] = ACT_LFE;
            chIndex[cc] = lc;
            return 1;
          }
          ec++;
          cc++;
          lc++;
        }
        break;

      /* Non audio elements */
      case ID_CCE:
        /* search in cce channels */
        for (i = 0; i < pPce->NumValidCcElements; i++) {
          if (pPce->ValidCcElementTagSelect[i] == tag) {
            return 1;
          }
        }
        break;
      case ID_DSE:
        /* search associated data elements */
        for (i = 0; i < pPce->NumAssocDataElements; i++) {
          if (pPce->AssocDataElementTagSelect[i] == tag) {
            return 1;
          }
        }
        break;
      default:
        return 0;
      }
      return 0;  /* not found in any list */
    }
#endif /* TP_PCE_ENABLE */
  }

  return 1;
}

#ifdef  TP_PCE_ENABLE
int CProgramConfig_GetElementTable(
        const CProgramConfig *pPce,
        MP4_ELEMENT_ID  elList[]
       )
{
  int i, el = 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;
  }


  return el;
}
#endif

static AUDIO_OBJECT_TYPE getAOT(HANDLE_FDK_BITSTREAM bs)
{
  int tmp = 0;

  tmp = FDKreadBits(bs,5);
  if (tmp == AOT_ESCAPE) {
    int tmp2 = FDKreadBits(bs,6);
    tmp = 32 + tmp2;
  }

  return (AUDIO_OBJECT_TYPE)tmp;
}

static INT getSampleRate(HANDLE_FDK_BITSTREAM bs, UCHAR *index, int nBits)
{
  INT sampleRate;
  int idx;

  idx = FDKreadBits(bs, nBits);
  if( idx == (1<<nBits)-1 ) {
    if(FDKgetValidBits(bs) < 24) {
      return 0;
    }
    sampleRate = FDKreadBits(bs,24);
  } else {
    sampleRate = SamplingRateTable[idx];
  }

  *index = idx;

  return sampleRate;
}

#ifdef TP_GA_ENABLE
static
TRANSPORTDEC_ERROR GaSpecificConfig_Parse( CSGaSpecificConfig    *self,
                                           CSAudioSpecificConfig *asc,
                                           HANDLE_FDK_BITSTREAM   bs,
                                           UINT                   ascStartAnchor )
{
  TRANSPORTDEC_ERROR ErrorStatus = TRANSPORTDEC_OK;

  self->m_frameLengthFlag = FDKreadBits(bs,1);

  self->m_dependsOnCoreCoder = FDKreadBits(bs,1);

  if( self->m_dependsOnCoreCoder )
    self->m_coreCoderDelay = FDKreadBits(bs,14);

  self->m_extensionFlag = FDKreadBits(bs,1);

  if( asc->m_channelConfiguration == 0 ) {
    CProgramConfig_Read(&asc->m_progrConfigElement, bs, ascStartAnchor);
  }

  if ((asc->m_aot == AOT_AAC_SCAL) || (asc->m_aot == AOT_ER_AAC_SCAL)) {
    self->m_layer = FDKreadBits(bs,3);
  }

  if (self->m_extensionFlag) {
    if (asc->m_aot == AOT_ER_BSAC) {
      self->m_numOfSubFrame = FDKreadBits(bs,5);
      self->m_layerLength   = FDKreadBits(bs,11);
    }

    if ((asc->m_aot == AOT_ER_AAC_LC)   || (asc->m_aot == AOT_ER_AAC_LTP)  ||
        (asc->m_aot == AOT_ER_AAC_SCAL) || (asc->m_aot == AOT_ER_AAC_LD))
    {
      asc->m_vcb11Flag = FDKreadBits(bs,1); /* aacSectionDataResilienceFlag */
      asc->m_rvlcFlag  = FDKreadBits(bs,1); /* aacScalefactorDataResilienceFlag */
      asc->m_hcrFlag   = FDKreadBits(bs,1); /* aacSpectralDataResilienceFlag */
    }

    self->m_extensionFlag3 = FDKreadBits(bs,1);

  }
  return (ErrorStatus);
}
#endif /* TP_GA_ENABLE */





#ifdef TP_ELD_ENABLE

static INT ld_sbr_header( const CSAudioSpecificConfig *asc,
                           HANDLE_FDK_BITSTREAM hBs, 
                           CSTpCallBacks *cb )
{
  const int channelConfiguration = asc->m_channelConfiguration;
  int i = 0;
  INT error = 0;

  if (channelConfiguration == 2) {
    error = cb->cbSbr(cb->cbSbrData, hBs, asc->m_samplingFrequency, asc->m_extensionSamplingFrequency, asc->m_samplesPerFrame, AOT_ER_AAC_ELD, ID_CPE, i++);
  } else {
    error = cb->cbSbr(cb->cbSbrData, hBs, asc->m_samplingFrequency, asc->m_extensionSamplingFrequency, asc->m_samplesPerFrame, AOT_ER_AAC_ELD, ID_SCE, i++);
  }

  switch ( channelConfiguration ) {
    case 5:
      error |= cb->cbSbr(cb->cbSbrData, hBs, asc->m_samplingFrequency, asc->m_extensionSamplingFrequency, asc->m_samplesPerFrame, AOT_ER_AAC_ELD, ID_CPE, i++);
    case 3:
      error |= cb->cbSbr(cb->cbSbrData, hBs, asc->m_samplingFrequency, asc->m_extensionSamplingFrequency, asc->m_samplesPerFrame, AOT_ER_AAC_ELD, ID_CPE, i++);
      break;

    case 7:
      error |= cb->cbSbr(cb->cbSbrData, hBs, asc->m_samplingFrequency, asc->m_extensionSamplingFrequency, asc->m_samplesPerFrame, AOT_ER_AAC_ELD, ID_SCE, i++);
    case 6:
      error |= cb->cbSbr(cb->cbSbrData, hBs, asc->m_samplingFrequency, asc->m_extensionSamplingFrequency, asc->m_samplesPerFrame, AOT_ER_AAC_ELD, ID_CPE, i++);
    case 4:
      error |= cb->cbSbr(cb->cbSbrData, hBs, asc->m_samplingFrequency, asc->m_extensionSamplingFrequency, asc->m_samplesPerFrame, AOT_ER_AAC_ELD, ID_CPE, i++);
      break;
  }

  return error;
}

static
TRANSPORTDEC_ERROR EldSpecificConfig_Parse(
        CSAudioSpecificConfig *asc,
        HANDLE_FDK_BITSTREAM hBs,
        CSTpCallBacks *cb
        )
{
  TRANSPORTDEC_ERROR ErrorStatus = TRANSPORTDEC_OK;
  CSEldSpecificConfig *esc = &asc->m_sc.m_eldSpecificConfig;
  ASC_ELD_EXT_TYPE eldExtType;
  int eldExtLen, len, cnt;

  FDKmemclear(esc, sizeof(CSEldSpecificConfig));

  esc->m_frameLengthFlag = FDKreadBits(hBs, 1 );
  if (esc->m_frameLengthFlag) {
    asc->m_samplesPerFrame = 480;
  } else {
    asc->m_samplesPerFrame = 512;
  }

  asc->m_vcb11Flag = FDKreadBits(hBs, 1 );
  asc->m_rvlcFlag  = FDKreadBits(hBs, 1 );
  asc->m_hcrFlag   = FDKreadBits(hBs, 1 );

  esc->m_sbrPresentFlag     = FDKreadBits(hBs, 1 );

  if (esc->m_sbrPresentFlag == 1) {
    esc->m_sbrSamplingRate    = FDKreadBits(hBs, 1 ); /* 0: single rate, 1: dual rate */
    esc->m_sbrCrcFlag         = FDKreadBits(hBs, 1 );

    asc->m_extensionSamplingFrequency = asc->m_samplingFrequency << esc->m_sbrSamplingRate;

    if (cb->cbSbr != NULL){
      if ( 0 != ld_sbr_header(asc, hBs, cb) ) {
        return TRANSPORTDEC_PARSE_ERROR;
      }
    }
  }
  esc->m_useLdQmfTimeAlign = 0;

  /* new ELD syntax */
  /* parse ExtTypeConfigData */
  while ((eldExtType = (ASC_ELD_EXT_TYPE)FDKreadBits(hBs, 4 )) != ELDEXT_TERM) {
    eldExtLen = len = FDKreadBits(hBs, 4 );
    if ( len == 0xf ) {
      len = FDKreadBits(hBs, 8 );
      eldExtLen += len;

      if ( len == 0xff ) {
        len = FDKreadBits(hBs, 16 );
        eldExtLen += len;
      }
    }

    switch (eldExtType) {
      case ELDEXT_LDSAC:
        esc->m_useLdQmfTimeAlign = 1;
        if (cb->cbSsc != NULL) {
          ErrorStatus = (TRANSPORTDEC_ERROR)cb->cbSsc(
                  cb->cbSscData,
                  hBs,
                  asc->m_aot,
                  asc->m_samplingFrequency,
                  1,  /* muxMode */
                  len
                  );
        } else {
          ErrorStatus = TRANSPORTDEC_UNSUPPORTED_FORMAT;
        }
        if (ErrorStatus != TRANSPORTDEC_OK) {
          goto bail;
        }
        break;
      default:
        for(cnt=0; cnt<len; cnt++) {
          FDKreadBits(hBs, 8 );
        }
        break;
      /* add future eld extension configs here */
    }
  }
bail:
  return (ErrorStatus);
}
#endif /* TP_ELD_ENABLE */


static
TRANSPORTDEC_ERROR AudioSpecificConfig_ExtensionParse(CSAudioSpecificConfig *self, HANDLE_FDK_BITSTREAM bs, CSTpCallBacks *cb)
{
  TP_ASC_EXTENSION_ID  lastAscExt, ascExtId = ASCEXT_UNKOWN;
  INT  bitsAvailable = (INT)FDKgetValidBits(bs);
  
  while (bitsAvailable >= 11)
  {
    lastAscExt = ascExtId;
    ascExtId   = (TP_ASC_EXTENSION_ID)FDKreadBits(bs, 11);
    bitsAvailable -= 11;

    switch (ascExtId) {
    case ASCEXT_SBR:    /* 0x2b7 */
      if ( (self->m_extensionAudioObjectType != AOT_SBR) && (bitsAvailable >= 5) ) {
        self->m_extensionAudioObjectType = getAOT(bs);

        if ( (self->m_extensionAudioObjectType == AOT_SBR)
          || (self->m_extensionAudioObjectType == AOT_ER_BSAC) )
        { /* Get SBR extension configuration */
          self->m_sbrPresentFlag = FDKreadBits(bs, 1);
          bitsAvailable -= 1;

          if ( self->m_sbrPresentFlag == 1 ) {
            self->m_extensionSamplingFrequency = getSampleRate(bs, &self->m_extensionSamplingFrequencyIndex, 4);

            if ((INT)self->m_extensionSamplingFrequency <= 0) {
              return TRANSPORTDEC_PARSE_ERROR;
            }
          }
          if ( self->m_extensionAudioObjectType == AOT_ER_BSAC ) {
            self->m_extensionChannelConfiguration = FDKreadBits(bs, 4);
            bitsAvailable -= 4;
          }
        }
        /* Update counter because of variable length fields (AOT and sampling rate) */
        bitsAvailable = (INT)FDKgetValidBits(bs);
      }
      break;
    case ASCEXT_PS:     /* 0x548 */
      if ( (lastAscExt == ASCEXT_SBR)
        && (self->m_extensionAudioObjectType == AOT_SBR)
        && (bitsAvailable > 0) )
      { /* Get PS extension configuration */
        self->m_psPresentFlag = FDKreadBits(bs, 1);
        bitsAvailable -= 1;
      }
      break;
    case ASCEXT_MPS:    /* 0x76a */
      if ( self->m_extensionAudioObjectType == AOT_MPEGS )
        break;
    case ASCEXT_LDMPS:  /* 0x7cc */
      if ( (ascExtId == ASCEXT_LDMPS)
        && (self->m_extensionAudioObjectType == AOT_LD_MPEGS) )
        break;
      if (bitsAvailable >= 1)
      {
        bitsAvailable -= 1;
        if ( FDKreadBits(bs, 1) ) {  /* self->m_mpsPresentFlag */
          int sscLen = FDKreadBits(bs, 8);
          bitsAvailable -= 8;
          if (sscLen == 0xFF) {
            sscLen += FDKreadBits(bs, 16);
            bitsAvailable -= 16;
          }
          if (cb->cbSsc != NULL) {
            cb->cbSsc(
                    cb->cbSscData,
                    bs,
                    self->m_aot,
                    self->m_samplingFrequency,
                    1,
                    sscLen
                    );
          } else
            FDKpushFor(bs, sscLen);  /* Skip SSC to be able to read the next extension if there is one. */

          bitsAvailable -= sscLen*8;
        }
      }
      break;
    default:
      return TRANSPORTDEC_UNSUPPORTED_FORMAT;
    }
  }

  return TRANSPORTDEC_OK;
}

/*
 * API Functions
 */

void AudioSpecificConfig_Init(CSAudioSpecificConfig *asc)
{
  FDKmemclear(asc, sizeof(CSAudioSpecificConfig));

  /* Init all values that should not be zero. */
  asc->m_aot                    = AOT_NONE;
  asc->m_samplingFrequencyIndex = 0xf;
  asc->m_epConfig               = -1;
  asc->m_extensionAudioObjectType        = AOT_NULL_OBJECT;
#ifdef TP_PCE_ENABLE
  CProgramConfig_Init(&asc->m_progrConfigElement);
#endif
}

TRANSPORTDEC_ERROR AudioSpecificConfig_Parse(
        CSAudioSpecificConfig *self,
        HANDLE_FDK_BITSTREAM   bs,
        int                    fExplicitBackwardCompatible,
        CSTpCallBacks      *cb
        )
{
  TRANSPORTDEC_ERROR ErrorStatus = TRANSPORTDEC_OK;
  UINT ascStartAnchor = FDKgetValidBits(bs);
  int frameLengthFlag = -1;

  AudioSpecificConfig_Init(self);

  self->m_aot = getAOT(bs);
  self->m_samplingFrequency = getSampleRate(bs, &self->m_samplingFrequencyIndex, 4);
  if (self->m_samplingFrequency <= 0) {
    return TRANSPORTDEC_PARSE_ERROR;
  }

  self->m_channelConfiguration = FDKreadBits(bs,4);

  /* SBR extension ( explicit non-backwards compatible mode ) */
  self->m_sbrPresentFlag = 0;
  self->m_psPresentFlag  = 0;

  if ( self->m_aot == AOT_SBR || self->m_aot == AOT_PS ) {
    self->m_extensionAudioObjectType = AOT_SBR;

    self->m_sbrPresentFlag = 1;
    if ( self->m_aot == AOT_PS ) {
      self->m_psPresentFlag = 1;
    }

    self->m_extensionSamplingFrequency = getSampleRate(bs, &self->m_extensionSamplingFrequencyIndex, 4);
    self->m_aot = getAOT(bs);

  } else {
    self->m_extensionAudioObjectType = AOT_NULL_OBJECT;
  }

  /* Parse whatever specific configs */
  switch (self->m_aot)
  {
#ifdef TP_GA_ENABLE
    case AOT_AAC_LC:
    case AOT_ER_AAC_LC:
    case AOT_ER_AAC_LD:
    case AOT_ER_AAC_SCAL:
    case AOT_ER_BSAC:
      if ((ErrorStatus = GaSpecificConfig_Parse(&self->m_sc.m_gaSpecificConfig, self, bs, ascStartAnchor)) != TRANSPORTDEC_OK ) {
        return (ErrorStatus);
      }
      frameLengthFlag = self->m_sc.m_gaSpecificConfig.m_frameLengthFlag;
      break;
#endif /* TP_GA_ENABLE */
    case AOT_MPEGS:
      if (cb->cbSsc != NULL) {
        cb->cbSsc(
                cb->cbSscData,
                bs,
                self->m_aot,
                self->m_samplingFrequency,
                1,
                0  /* don't know the length */
                );
      } else {
        return TRANSPORTDEC_UNSUPPORTED_FORMAT;
      }
      break;
#ifdef TP_ELD_ENABLE
    case AOT_ER_AAC_ELD:
      if ((ErrorStatus = EldSpecificConfig_Parse(self, bs, cb)) != TRANSPORTDEC_OK ) {
        return (ErrorStatus);
      }
      frameLengthFlag = self->m_sc.m_eldSpecificConfig.m_frameLengthFlag;
      self->m_sbrPresentFlag = self->m_sc.m_eldSpecificConfig.m_sbrPresentFlag;
      self->m_extensionSamplingFrequency = (self->m_sc.m_eldSpecificConfig.m_sbrSamplingRate+1) * self->m_samplingFrequency;
      break;
#endif /* TP_ELD_ENABLE */

    default:
      return TRANSPORTDEC_UNSUPPORTED_FORMAT;
      break;
  }

  /* Frame length */
  switch (self->m_aot)
  {
#if defined(TP_GA_ENABLE) || defined(TP_USAC_ENABLE)
    case AOT_AAC_LC:
    case AOT_ER_AAC_LC:
    case AOT_ER_AAC_SCAL:
    case AOT_ER_BSAC:
    /*case AOT_USAC:*/
      if (!frameLengthFlag)
        self->m_samplesPerFrame = 1024;
      else
        self->m_samplesPerFrame = 960;
      break;
#endif /* TP_GA_ENABLE */
#if defined(TP_GA_ENABLE)
    case AOT_ER_AAC_LD:
      if (!frameLengthFlag)
        self->m_samplesPerFrame = 512;
      else
        self->m_samplesPerFrame = 480;
      break;
#endif /* defined(TP_GA_ENABLE) */
    default:
      break;
  }

  switch (self->m_aot)
  {
    case AOT_ER_AAC_LC:
    case AOT_ER_AAC_LD:
    case AOT_ER_AAC_ELD:
    case AOT_ER_AAC_SCAL:
    case AOT_ER_CELP:
    case AOT_ER_HVXC:
    case AOT_ER_BSAC:
      self->m_epConfig = FDKreadBits(bs,2);

      if (self->m_epConfig > 1) {
        return TRANSPORTDEC_UNSUPPORTED_FORMAT; // EPCONFIG;
      }
      break;
    default:
      break;
  }

  if (fExplicitBackwardCompatible) {
    ErrorStatus = AudioSpecificConfig_ExtensionParse(self, bs, cb);
  }

  return (ErrorStatus);
}