path: root/libMpegTPEnc/src/tpenc_latm.cpp

/* -----------------------------------------------------------------------------------------------------------
Software License for The Fraunhofer FDK AAC Codec Library for Android

� Copyright  1995 - 2012 Fraunhofer-Gesellschaft zur F�rderung der angewandten Forschung e.V.
  All rights reserved.

 1.    INTRODUCTION
The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements
the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio.
This FDK AAC Codec software is intended to be used on a wide variety of Android devices.

AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual
audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by
independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part
of the MPEG specifications.

Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer)
may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners
individually for the purpose of encoding or decoding bit streams in products that are compliant with
the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license
these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec
software may already be covered under those patent licenses when it is used for those licensed purposes only.

Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality,
are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional
applications information and documentation.

2.    COPYRIGHT LICENSE

Redistribution and use in source and binary forms, with or without modification, are permitted without
payment of copyright license fees provided that you satisfy the following conditions:

You must retain the complete text of this software license in redistributions of the FDK AAC Codec or
your modifications thereto in source code form.

You must retain the complete text of this software license in the documentation and/or other materials
provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form.
You must make available free of charge copies of the complete source code of the FDK AAC Codec and your
modifications thereto to recipients of copies in binary form.

The name of Fraunhofer may not be used to endorse or promote products derived from this library without
prior written permission.

You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec
software or your modifications thereto.

Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software
and the date of any change. For modified versions of the FDK AAC Codec, the term
"Fraunhofer FDK AAC Codec Library for Android" must be replaced by the term
"Third-Party Modified Version of the Fraunhofer FDK AAC Codec Library for Android."

3.    NO PATENT LICENSE

NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer,
ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with
respect to this software.

You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized
by appropriate patent licenses.

4.    DISCLAIMER

This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright holders and contributors
"AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, including but not limited to the implied warranties
of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages,
including but not limited to procurement of substitute goods or services; loss of use, data, or profits,
or business interruption, however caused and on any theory of liability, whether in contract, strict
liability, or tort (including negligence), arising in any way out of the use of this software, even if
advised of the possibility of such damage.

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 Encoder  **************************

   Author(s):
   Description:

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

#include "tpenc_latm.h"


#include "genericStds.h"

static const short celpFrameLengthTable[64] = {
 154, 170, 186, 147, 156, 165, 114, 120,
 186, 126, 132, 138, 142, 146, 154, 166,
 174, 182, 190, 198, 206, 210, 214, 110,
 114, 118, 120, 122, 218, 230, 242, 254,
 266, 278, 286, 294, 318, 342, 358, 374,
 390, 406, 422, 136, 142, 148, 154, 160,
 166, 170, 174, 186, 198, 206, 214, 222,
 230, 238, 216, 160, 280, 338, 0,   0
};

/*******
 write value to transport stream
 first two bits define the size of the value itself
 then the value itself, with a size of 0-3 bytes
*******/
static
UINT transportEnc_LatmWriteValue(HANDLE_FDK_BITSTREAM hBs, int value)
{
  UCHAR valueBytes = 4;
  unsigned int bitsWritten = 0;
  int i;

  if ( value < (1<<8) ) {
    valueBytes = 1;
  } else if ( value < (1<<16) ) {
    valueBytes = 2;
  } else if ( value < (1<<24) ) {
    valueBytes = 3;
  } else {
    valueBytes = 4;
  }

  FDKwriteBits(hBs, valueBytes-1, 2 ); /* size of value in Bytes */
  for (i=0; i<valueBytes; i++) {
    /* write most significant Byte first */
    FDKwriteBits(hBs, (UCHAR)(value>>((valueBytes-1-i)<<3)), 8);
  }

  bitsWritten = (valueBytes<<3)+2;

  return bitsWritten;
}

static
UINT transportEnc_LatmCountFixBitDemandHeader ( HANDLE_LATM_STREAM hAss )
{
  int bitDemand = 0;
  int insertSetupData = 0 ;

  /* only if start of new latm frame */
  if (hAss->subFrameCnt==0)
  {
    /* AudioSyncStream */

    if (hAss->tt == TT_MP4_LOAS) {
      bitDemand += 11 ;             /* syncword */
      bitDemand += 13 ;             /* audioMuxLengthBytes */
    }

    /* AudioMuxElement*/

    /* AudioMuxElement::Stream Mux Config */
    if (hAss->muxConfigPeriod > 0) {
      insertSetupData = (hAss->latmFrameCounter == 0);
    } else {
      insertSetupData = 0;
    }

    if (hAss->tt != TT_MP4_LATM_MCP0) {
      /* AudioMuxElement::useSameStreamMux Flag */
      bitDemand+=1;

      if( insertSetupData ) {
        bitDemand += hAss->streamMuxConfigBits;
      }
    }

    /* AudioMuxElement::otherDataBits */
    bitDemand += 8*hAss->otherDataLenBytes;

    /* AudioMuxElement::ByteAlign */
    if ( bitDemand % 8 ) {
       hAss->fillBits = 8 - (bitDemand % 8);
       bitDemand += hAss->fillBits ;
    } else {
      hAss->fillBits = 0;
    }
  }

  return bitDemand ;
}

static
UINT transportEnc_LatmCountVarBitDemandHeader ( HANDLE_LATM_STREAM hAss , unsigned int streamDataLength )
{
  int bitDemand = 0;
  int  prog, layer;

  /* Payload Length Info*/
  if( hAss->allStreamsSameTimeFraming ) {
    for( prog=0; prog<hAss->noProgram; prog++ ) {
      for( layer=0; layer<LATM_MAX_LAYERS; layer++ ) {
        LATM_LAYER_INFO *p_linfo = &(hAss->m_linfo[prog][layer]);

        if( p_linfo->streamID >= 0 ) {
          switch( p_linfo->frameLengthType ) {
          case 0:
            if ( streamDataLength > 0 ) {
              streamDataLength -= bitDemand ;
              while( streamDataLength >= (255<<3) ) {
                bitDemand+=8;
                streamDataLength -= (255<<3);
              }
              bitDemand += 8;
            }
            break;

          case 1:
          case 4:
          case 6:
            bitDemand += 2;
            break;

          default:
            return 0;
          }
        }
      }
    }
  } else {
    /* there are many possibilities to use this mechanism.  */
    switch( hAss->varMode ) {
    case LATMVAR_SIMPLE_SEQUENCE: {
      /* Use the sequence generated by the encoder */
      //int streamCntPosition = transportEnc_SetWritePointer( hAss->hAssemble, 0 );
      //int streamCntPosition = FDKgetValidBits( hAss->hAssemble );
      bitDemand+=4;

      hAss->varStreamCnt = 0;
      for( prog=0; prog<hAss->noProgram; prog++ ) {
        for( layer=0; layer<LATM_MAX_LAYERS; layer++ ) {
          LATM_LAYER_INFO *p_linfo = &(hAss->m_linfo[prog][layer]);

          if( p_linfo->streamID >= 0 ) {

            bitDemand+=4; /* streamID */
            switch( p_linfo->frameLengthType ) {
            case 0:
              streamDataLength -= bitDemand ;
              while( streamDataLength >= (255<<3) ) {
                bitDemand+=8;
                streamDataLength -= (255<<3);
              }

              bitDemand += 8;
              break;
              /*bitDemand += 1; endFlag
              break;*/

            case 1:
            case 4:
            case 6:

              break;

            default:
              return  0;
            }
            hAss->varStreamCnt++;
          }
        }
      }
      bitDemand+=4;
      //transportEnc_UpdateBitstreamField( hAss->hAssemble, streamCntPosition, hAss->varStreamCnt-1, 4 );
      //UINT pos = streamCntPosition-FDKgetValidBits(hAss->hAssemble);
      //FDKpushBack( hAss->hAssemble,  pos);
      //FDKwriteBits( hAss->hAssemble, hAss->varStreamCnt-1, 4);
      //FDKpushFor( hAss->hAssemble, pos-4);
    }
    break;

    default:
      return  0;
    }
  }

  return bitDemand ;
}

TRANSPORTENC_ERROR
CreateStreamMuxConfig(
                      HANDLE_LATM_STREAM hAss,
                      HANDLE_FDK_BITSTREAM hBs,
                      int bufferFullness,
                      CSTpCallBacks *cb
                     )
{
  INT streamIDcnt, tmp;
  int layer, prog;

  USHORT coreFrameOffset=0;

  hAss->audioMuxVersionA    = 0; /* for future extensions */
  hAss->streamMuxConfigBits = 0;

  FDKwriteBits( hBs, hAss->audioMuxVersion, 1 );                   /* audioMuxVersion */
  hAss->streamMuxConfigBits += 1;

  if ( hAss->audioMuxVersion == 1 ) {
    FDKwriteBits( hBs, hAss->audioMuxVersionA, 1 );                /* audioMuxVersionA */
    hAss->streamMuxConfigBits+=1;
  }

  if ( hAss->audioMuxVersionA == 0 )
  {
    if ( hAss->audioMuxVersion == 1 ) {
      hAss->streamMuxConfigBits+= transportEnc_LatmWriteValue( hBs, hAss->taraBufferFullness );/* taraBufferFullness */
    }
    FDKwriteBits( hBs, hAss->allStreamsSameTimeFraming ? 1:0, 1 ); /* allStreamsSameTimeFraming */
    FDKwriteBits( hBs, hAss->noSubframes-1, 6 );                   /* Number of Subframes */
    FDKwriteBits( hBs, hAss->noProgram-1, 4 );                     /* Number of Programs */

    hAss->streamMuxConfigBits+=11;

    streamIDcnt = 0;
    for( prog=0; prog<hAss->noProgram; prog++ ) {
      int transLayer = 0;

      FDKwriteBits( hBs, hAss->noLayer[prog]-1, 3 );
      hAss->streamMuxConfigBits+=3;

      for( layer=0; layer<LATM_MAX_LAYERS; layer++ ) {
        LATM_LAYER_INFO   *p_linfo = &(hAss->m_linfo[prog][layer]);
        CODER_CONFIG *p_lci   = hAss->config[prog][layer];

        p_linfo->streamID = -1;

        if( hAss->config[prog][layer] != NULL ) {
          int useSameConfig = 0;

          if( transLayer > 0 ) {
            FDKwriteBits( hBs, useSameConfig ? 1 : 0, 1 );
            hAss->streamMuxConfigBits+=1;
          }
          if( (useSameConfig == 0) || (transLayer==0) ) {
            UINT bits;

            if ( hAss->audioMuxVersion == 1 ) {
              FDKpushFor(hBs, 2); /* align to ASC, even if we do not know the length of the "ascLen" field yet */
            }

            bits = FDKgetValidBits( hBs );

            transportEnc_writeASC(
                    hBs,
                    hAss->config[prog][layer],
                    cb
                    );

            bits = FDKgetValidBits( hBs ) - bits;

            if ( hAss->audioMuxVersion == 1 ) {
              FDKpushBack(hBs, bits+2);
              hAss->streamMuxConfigBits += transportEnc_LatmWriteValue( hBs, bits );
              transportEnc_writeASC(
                      hBs,
                      hAss->config[prog][layer],
                      cb
                      );
            }

            hAss->streamMuxConfigBits += bits; /* add asc length to smc summary */
          }
          transLayer++;

          if( !hAss->allStreamsSameTimeFraming ) {
            if( streamIDcnt >= LATM_MAX_STREAM_ID )
              return TRANSPORTENC_INVALID_CONFIG;
          }
          p_linfo->streamID = streamIDcnt++;

          switch( p_lci->aot ) {
          case AOT_AAC_MAIN      :
          case AOT_AAC_LC        :
          case AOT_AAC_SSR       :
          case AOT_AAC_LTP       :
          case AOT_AAC_SCAL      :
          case AOT_ER_AAC_LD     :
          case AOT_ER_AAC_ELD    :
          case AOT_USAC:
          case AOT_RSVD50:
            p_linfo->frameLengthType = 0;

            FDKwriteBits( hBs, p_linfo->frameLengthType, 3 );                        /* frameLengthType */
            FDKwriteBits( hBs, bufferFullness, 8 );                           /* bufferFullness */
            hAss->streamMuxConfigBits+=11;

            if ( !hAss->allStreamsSameTimeFraming ) {
              CODER_CONFIG *p_lci_prev = hAss->config[prog][layer-1];
              if ( ((p_lci->aot == AOT_AAC_SCAL) || (p_lci->aot == AOT_ER_AAC_SCAL)) &&
                   ((p_lci_prev->aot == AOT_CELP) || (p_lci_prev->aot == AOT_ER_CELP)) ) {
                FDKwriteBits( hBs, coreFrameOffset, 6 );                      /* coreFrameOffset */
                hAss->streamMuxConfigBits+=6;
              }
            }
            break;

          case AOT_TWIN_VQ:
            p_linfo->frameLengthType = 1;
            tmp = ( (p_lci->bitsFrame+7) >> 3 ) - 20;                            /* transmission frame length in bytes */
            if( (tmp < 0) ) {
              return TRANSPORTENC_INVALID_TRANSMISSION_FRAME_LENGTH;
            }
            FDKwriteBits( hBs, p_linfo->frameLengthType, 3 );          /* frameLengthType */
            FDKwriteBits( hBs, tmp, 9 );
            hAss->streamMuxConfigBits+=12;

            p_linfo->frameLengthBits = (tmp+20) << 3;
            break;

          case AOT_CELP:
            p_linfo->frameLengthType = 4;
            FDKwriteBits( hBs, p_linfo->frameLengthType, 3 );          /* frameLengthType */
            hAss->streamMuxConfigBits+=3;
            {
              int i;
              for( i=0; i<62; i++ ) {
                if( celpFrameLengthTable[i] == p_lci->bitsFrame )
                  break;
              }
              if( i>=62 ) {
                return TRANSPORTENC_INVALID_CELP_FRAME_LENGTH;
              }

              FDKwriteBits( hBs, i, 6 );                                /* CELPframeLengthTabelIndex */
              hAss->streamMuxConfigBits+=6;
            }
            p_linfo->frameLengthBits = p_lci->bitsFrame;
            break;

          case AOT_HVXC:
            p_linfo->frameLengthType = 6;
            FDKwriteBits( hBs, p_linfo->frameLengthType, 3 );          /* frameLengthType */
            hAss->streamMuxConfigBits+=3;
            {
              int i;

              if( p_lci->bitsFrame == 40 ) {
                i = 0;
              } else if( p_lci->bitsFrame == 80 ) {
                i = 1;
              } else {
                return TRANSPORTENC_INVALID_FRAME_BITS;
              }
              FDKwriteBits( hBs, i, 1 );                                /* HVXCframeLengthTableIndex */
              hAss->streamMuxConfigBits+=1;
            }
            p_linfo->frameLengthBits = p_lci->bitsFrame;
            break;

          case AOT_NULL_OBJECT:
          default:
            return TRANSPORTENC_INVALID_AOT;
          }
        }
      }
    }

    FDKwriteBits( hBs, (hAss->otherDataLenBytes>0) ? 1:0, 1 );      /* otherDataPresent */
    hAss->streamMuxConfigBits+=1;

    if( hAss->otherDataLenBytes > 0 ) {

      INT otherDataLenTmp = hAss->otherDataLenBytes;
      INT escCnt = 0;
      INT otherDataLenEsc = 1;

      while(otherDataLenTmp) {
        otherDataLenTmp >>= 8;
        escCnt ++;
      }

      do {
        otherDataLenTmp = (hAss->otherDataLenBytes>>(escCnt*8)) & 0xFF;
        escCnt--;
        otherDataLenEsc = escCnt>0;

        FDKwriteBits( hBs, otherDataLenEsc, 1 );
        FDKwriteBits( hBs, otherDataLenTmp, 8 );
        hAss->streamMuxConfigBits+=9;
      } while(otherDataLenEsc);
    }

    {
      USHORT crcCheckPresent=0;
      USHORT crcCheckSum=0;

      FDKwriteBits( hBs, crcCheckPresent, 1 );               /* crcCheckPresent */
      hAss->streamMuxConfigBits+=1;
      if ( crcCheckPresent ){
        FDKwriteBits( hBs, crcCheckSum, 8 );                 /* crcCheckSum */
        hAss->streamMuxConfigBits+=8;
      }
    }

  } else {  /* if ( audioMuxVersionA == 0 ) */

    /* for future extensions */

  }

  return TRANSPORTENC_OK;
}


static TRANSPORTENC_ERROR
WriteAuPayloadLengthInfo( HANDLE_FDK_BITSTREAM hBitStream, int AuLengthBits )
{
  int restBytes;

  if( AuLengthBits % 8 )
    return TRANSPORTENC_INVALID_AU_LENGTH;

  while( AuLengthBits >= 255*8 ) {
    FDKwriteBits( hBitStream, 255, 8 );  /* 255 shows incomplete AU */
    AuLengthBits -= (255*8);
  }

  restBytes = (AuLengthBits) >> 3;
  FDKwriteBits( hBitStream, restBytes, 8 );

  return TRANSPORTENC_OK;
}

static
TRANSPORTENC_ERROR transportEnc_LatmSetNrOfSubframes( HANDLE_LATM_STREAM hAss,
                                                      INT noSubframes_next)    /* nr of access units / payloads within a latm frame */
{
  /* sanity chk */
  if (noSubframes_next < 1 || noSubframes_next > MAX_NR_OF_SUBFRAMES) {
    return TRANSPORTENC_LATM_INVALID_NR_OF_SUBFRAMES;
  }

  hAss->noSubframes_next = noSubframes_next;

  /* if at start then we can take over the value immediately, otherwise we have to wait for the next SMC */
  if ( (hAss->subFrameCnt == 0) && (hAss->latmFrameCounter == 0) ) {
    hAss->noSubframes = noSubframes_next;
  }

  return TRANSPORTENC_OK;
}

static
int allStreamsSameTimeFraming( HANDLE_LATM_STREAM hAss, UCHAR noProgram, UCHAR noLayer[] /* return */ )
{
  int prog, layer;

  signed int lastNoSamples   = -1;
  signed int minFrameSamples = FDK_INT_MAX;
  signed int maxFrameSamples = 0;

  signed int highestSamplingRate = -1;

  for( prog=0; prog<noProgram; prog++ ) {
    noLayer[prog] = 0;

    for( layer=0; layer<LATM_MAX_LAYERS; layer++ )
    {
      if( hAss->config[prog][layer] != NULL )
      {
        INT hsfSamplesFrame;

        noLayer[prog]++;

        if( highestSamplingRate < 0 )
          highestSamplingRate = hAss->config[prog][layer]->samplingRate;

        hsfSamplesFrame = hAss->config[prog][layer]->samplesPerFrame  * highestSamplingRate / hAss->config[prog][layer]->samplingRate;

        if( hsfSamplesFrame <= minFrameSamples ) minFrameSamples = hsfSamplesFrame;
        if( hsfSamplesFrame >= maxFrameSamples ) maxFrameSamples = hsfSamplesFrame;

        if( lastNoSamples == -1 ) {
          lastNoSamples                             = hsfSamplesFrame;
        } else {
          if( hsfSamplesFrame != lastNoSamples ) {
            return 0;
          }
        }
      }
    }
  }

  return 1;
}

/**
 * Initialize LATM/LOAS Stream and add layer 0 at program 0.
 */
static
TRANSPORTENC_ERROR transportEnc_InitLatmStream( HANDLE_LATM_STREAM hAss,
                                                int                fractDelayPresent,
                                                signed int         muxConfigPeriod, /* insert setup data every muxConfigPeriod frames */
                                                UINT               audioMuxVersion,
                                                TRANSPORT_TYPE     tt
                                              )
{
  TRANSPORTENC_ERROR ErrorStatus = TRANSPORTENC_OK;

  if (hAss == NULL)
    return TRANSPORTENC_INVALID_PARAMETER;

  hAss->tt = tt;

  hAss->noProgram = 1;

  hAss->audioMuxVersion = audioMuxVersion;

  /* Fill noLayer array using hAss->config */
  hAss->allStreamsSameTimeFraming = allStreamsSameTimeFraming( hAss, hAss->noProgram, hAss->noLayer );
  /* Only allStreamsSameTimeFraming==1 is supported */
  FDK_ASSERT(hAss->allStreamsSameTimeFraming);

  hAss->fractDelayPresent = fractDelayPresent;
  hAss->otherDataLenBytes = 0;

  hAss->varMode = LATMVAR_SIMPLE_SEQUENCE;

  /* initialize counters */
  hAss->subFrameCnt                  = 0;
  hAss->noSubframes                  = DEFAULT_LATM_NR_OF_SUBFRAMES;
  hAss->noSubframes_next             = DEFAULT_LATM_NR_OF_SUBFRAMES;

  /* sync layer related */
  hAss->audioMuxLengthBytes     = 0;

  hAss->latmFrameCounter        = 0;
  hAss->muxConfigPeriod = muxConfigPeriod;

  return ErrorStatus;
}


/**
 *
 */
UINT transportEnc_LatmCountTotalBitDemandHeader ( HANDLE_LATM_STREAM hAss , unsigned int streamDataLength )
{
  UINT bitDemand = 0;

  switch (hAss->tt) {
  case TT_MP4_LOAS:
  case TT_MP4_LATM_MCP0:
  case TT_MP4_LATM_MCP1:
    if (hAss->subFrameCnt == 0) {
      bitDemand  = transportEnc_LatmCountFixBitDemandHeader ( hAss );
    }
    bitDemand += transportEnc_LatmCountVarBitDemandHeader ( hAss , streamDataLength /*- bitDemand*/);
    break;
  default:
    break;
  }

  return bitDemand;
}

static TRANSPORTENC_ERROR
AdvanceAudioMuxElement (
        HANDLE_LATM_STREAM   hAss,
        HANDLE_FDK_BITSTREAM hBs,
        int                  auBits,
        int                  bufferFullness,
        CSTpCallBacks    *cb
        )
{
  TRANSPORTENC_ERROR ErrorStatus = TRANSPORTENC_OK;
  int insertMuxSetup;

  /* Insert setup data to assemble Buffer */
  if (hAss->subFrameCnt == 0)
  {
    if (hAss->muxConfigPeriod > 0) {
      insertMuxSetup = (hAss->latmFrameCounter == 0);
    } else  {
      insertMuxSetup = 0;
    }

    if (hAss->tt != TT_MP4_LATM_MCP0) {
      if( insertMuxSetup ) {
        FDKwriteBits( hBs, 0, 1 );  /* useSameStreamMux useNewStreamMux */
        CreateStreamMuxConfig(hAss, hBs, bufferFullness, cb);
        if (ErrorStatus != TRANSPORTENC_OK)
          return ErrorStatus;
      } else {
        FDKwriteBits( hBs, 1, 1 );   /* useSameStreamMux */
      }
    }
  }

  /* PayloadLengthInfo */
  {
    int prog, layer;

    for (prog = 0; prog < hAss->noProgram; prog++) {
      for (layer = 0; layer < hAss->noLayer[prog]; layer++) {
        ErrorStatus = WriteAuPayloadLengthInfo( hBs, auBits );
        if (ErrorStatus != TRANSPORTENC_OK)
          return ErrorStatus;
      }
    }
  }
  /* At this point comes the access unit. */

  return TRANSPORTENC_OK;
}

TRANSPORTENC_ERROR
transportEnc_LatmWrite (
        HANDLE_LATM_STREAM    hAss,
        HANDLE_FDK_BITSTREAM  hBs,
        int                   auBits,
        int                   bufferFullness,
        CSTpCallBacks     *cb
        )
{
  TRANSPORTENC_ERROR ErrorStatus;

  if (hAss->subFrameCnt == 0) {
    /* Start new frame */
    FDKresetBitbuffer(hBs, BS_WRITER);
  }

  hAss->latmSubframeStart = FDKgetValidBits(hBs);

  /* Insert syncword and syncword distance
     - only if loas
     - we must update the syncword distance (=audiomuxlengthbytes) later
   */
  if( hAss->tt == TT_MP4_LOAS && hAss->subFrameCnt == 0)
  {
    /* Start new LOAS frame */
    FDKwriteBits( hBs, 0x2B7, 11 );
    hAss->audioMuxLengthBytes = 0;
    hAss->audioMuxLengthBytesPos = FDKgetValidBits( hBs );  /* store read pointer position */
    FDKwriteBits( hBs, hAss->audioMuxLengthBytes, 13 );
  }

  ErrorStatus = AdvanceAudioMuxElement(
          hAss,
          hBs,
          auBits,
          bufferFullness,
          cb
          );

  if (ErrorStatus != TRANSPORTENC_OK)
    return ErrorStatus;

  return ErrorStatus;
}

void transportEnc_LatmAdjustSubframeBits(HANDLE_LATM_STREAM    hAss,
                                         int                  *bits)
{
  /* Substract bits from possible previous subframe */
  *bits -= hAss->latmSubframeStart;
  /* Add fill bits */
  if (hAss->subFrameCnt == 0)
    *bits += hAss->fillBits;
}


void transportEnc_LatmGetFrame(HANDLE_LATM_STREAM    hAss,
                               HANDLE_FDK_BITSTREAM  hBs,
                               int                  *bytes)
{

  hAss->subFrameCnt++;
  if (hAss->subFrameCnt >= hAss->noSubframes)
  {

    /* Add LOAS frame length if required. */
    if (hAss->tt == TT_MP4_LOAS)
    {
      int latmBytes;

      latmBytes = (FDKgetValidBits(hBs)+7) >> 3;

      /* write length info into assembler buffer */
      hAss->audioMuxLengthBytes = latmBytes - 3; /* 3=Syncword + length */
      {
        FDK_BITSTREAM tmpBuf;

        FDKinitBitStream( &tmpBuf, hBs->hBitBuf.Buffer, hBs->hBitBuf.bufSize, 0, BS_WRITER ) ;
        FDKpushFor( &tmpBuf, hAss->audioMuxLengthBytesPos );
        FDKwriteBits( &tmpBuf, hAss->audioMuxLengthBytes, 13 );
        FDKsyncCache( &tmpBuf );
      }
    }

    /* Write AudioMuxElement byte alignment fill bits */
    FDKwriteBits(hBs, 0, hAss->fillBits);

    FDK_ASSERT( (FDKgetValidBits(hBs) % 8) == 0);

    hAss->subFrameCnt = 0;

    FDKsyncCache(hBs);
    *bytes = (FDKgetValidBits(hBs) + 7)>>3;
    //FDKfetchBuffer(hBs, buffer, (UINT*)bytes);

    if (hAss->muxConfigPeriod > 0)
    {
      hAss->latmFrameCounter++;

      if (hAss->latmFrameCounter >= hAss->muxConfigPeriod) {
        hAss->latmFrameCounter = 0;
        hAss->noSubframes = hAss->noSubframes_next;
      }
    }
  } else {
    /* No data this time */
    *bytes = 0;
  }
}

/**
 * Init LATM/LOAS
 */
TRANSPORTENC_ERROR transportEnc_Latm_Init(
        HANDLE_LATM_STREAM  hAss,
        HANDLE_FDK_BITSTREAM hBs,
        CODER_CONFIG  *layerConfig,
        UINT audioMuxVersion,
        TRANSPORT_TYPE tt,
        CSTpCallBacks *cb
        )
{
  TRANSPORTENC_ERROR ErrorStatus;
  int fractDelayPresent = 0;
  int prog, layer;

  int setupDataDistanceFrames = layerConfig->headerPeriod;

  FDK_ASSERT(setupDataDistanceFrames>=0);

  for (prog=0; prog<LATM_MAX_PROGRAMS; prog++) {
    for (layer=0; layer<LATM_MAX_LAYERS; layer++) {
      hAss->config[prog][layer] = NULL;
      hAss->m_linfo[prog][layer].streamID = -1;
    }
  }

  hAss->config[0][0] = layerConfig;
  hAss->m_linfo[0][0].streamID = 0;

  ErrorStatus = transportEnc_InitLatmStream( hAss,
                                             fractDelayPresent,
                                             setupDataDistanceFrames,
                                             (audioMuxVersion)?1:0,
                                             tt
                                             );
  if (ErrorStatus != TRANSPORTENC_OK)
    goto bail;

  ErrorStatus = transportEnc_LatmSetNrOfSubframes(
                                                   hAss,
                                                   layerConfig->nSubFrames
                                                  );
  if (ErrorStatus != TRANSPORTENC_OK)
    goto bail;

  /* Get the size of the StreamMuxConfig somehow */
  AdvanceAudioMuxElement(hAss, hBs, 0, 0, cb);
  //CreateStreamMuxConfig(hAss, hBs, 0);

bail:
  return ErrorStatus;
}