/*

* Copyright (c) 2010 Ixonos Plc.

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - Initial contribution

*

* Contributors:

* Ixonos Plc

*

* Description:

*

*/

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

  mp4aud.cpp - MPEG-4 Audio interface to MPEG-4 Systems layer.

  Author(s): Juha Ojanpera

  Copyright (c) 2001-2004 by Nokia Research Center, Speech and Audio Systems.

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

/*-- Project Headers. --*/

#include "nok_bits.h"

#include "mp4aud.h"

#include "AACAPI.h"

const int32 sample_rates[] = {

  96000, 88200, 64000, 48000, 44100, 32000, 24000, 22050, 16000, 12000, 

  11025, 8000, 0, 0, 0, 0

};

/*

 * Reads program configuration element from the specified bitstream.

 */

static INLINE int16

GetPCE(TBitStream *bs, ProgConfig *p, TInt *numChans)

{

  int16 i;

  p->tag = (int16) BsGetBits(bs, LEN_TAG);

  p->profile = (int16) BsGetBits(bs, LEN_PROFILE);

  p->sample_rate_idx = (int16) BsGetBits(bs, LEN_SAMP_IDX);

  p->front.num_ele = (int16) BsGetBits(bs, LEN_NUM_ELE);

  p->side.num_ele = (int16) BsGetBits(bs, LEN_NUM_ELE);

  p->back.num_ele = (int16) BsGetBits(bs, LEN_NUM_ELE);

  p->lfe.num_ele = (int16) BsGetBits(bs, LEN_NUM_LFE);

  p->data.num_ele = (int16) BsGetBits(bs, LEN_NUM_DAT);

  p->coupling.num_ele = (int16) BsGetBits(bs, LEN_NUM_CCE);

  p->mono_mix.present = (int16) BsGetBits(bs, 1);

  if(p->mono_mix.present == 1)

    p->mono_mix.ele_tag = (int16) BsGetBits(bs, LEN_TAG);

  p->stereo_mix.present = (int16) BsGetBits(bs, 1);

  if(p->stereo_mix.present == 1)

    p->stereo_mix.ele_tag = (int16) BsGetBits(bs, LEN_TAG);

  p->matrix_mix.present = (int16) BsGetBits(bs, 1);

  if(p->matrix_mix.present == 1)

  {

    p->matrix_mix.ele_tag = (int16) BsGetBits(bs, LEN_MMIX_IDX);

    p->matrix_mix.pseudo_enab = (int16) BsGetBits(bs, LEN_PSUR_ENAB);

  }

  for(i = 0; i < p->front.num_ele; i++)

  {

    p->front.ele_is_cpe[i] = (int16) BsGetBits(bs, LEN_ELE_IS_CPE);

    p->front.ele_tag[i] = (int16) BsGetBits(bs, LEN_TAG);

    *numChans += (p->front.ele_is_cpe[i] == 1) ? 2 : 1;

  }

  for(i = 0; i < p->side.num_ele; i++)

  {

    p->side.ele_is_cpe[i] = (int16) BsGetBits(bs, LEN_ELE_IS_CPE);

    p->side.ele_tag[i] = (int16) BsGetBits(bs, LEN_TAG);

    *numChans += (p->front.ele_is_cpe[i] == 1) ? 2 : 1;

  }

  for(i = 0; i < p->back.num_ele; i++)

  {

    p->back.ele_is_cpe[i] = (int16) BsGetBits(bs, LEN_ELE_IS_CPE);

    p->back.ele_tag[i] = (int16) BsGetBits(bs, LEN_TAG);

    *numChans += (p->front.ele_is_cpe[i] == 1) ? 2 : 1;

  }

  for(i = 0; i < p->lfe.num_ele; i++)

  {

    *numChans += 1;

    p->lfe.ele_is_cpe[i] = 0;

    p->lfe.ele_tag[i] = (int16) BsGetBits(bs, LEN_TAG);

  }

  for(i = 0; i < p->data.num_ele; i++)

  {

    p->data.ele_is_cpe[i] = 0;

    p->data.ele_tag[i] = (int16) BsGetBits(bs, LEN_TAG);

  }

  for(i = 0; i < p->coupling.num_ele; i++)

  {

    p->coupling.ele_is_cpe[i] = (int16) BsGetBits(bs, LEN_ELE_IS_CPE);

    p->coupling.ele_tag[i] = (int16) BsGetBits(bs, LEN_TAG);

  }

  BsByteAlign(bs);

  p->num_comment_bytes = (int16) BsGetBits(bs, LEN_COMMENT_BYTES);

  for(i = 0; i < p->num_comment_bytes; i++)

    p->comments[i] = (uint8) BsGetBits(bs, LEN_BYTE);

  p->comments[i] = 0;

  return (p->tag);

}

/*

 * Determines sampling rate index for the MPEG-4 decoder. The input sampling

 * rate as specified in the audio config part is not one of the rates listed

 * in the standard.

 */

static INLINE int16

DetermineSamplingFreqIdx(int32 samplingFreq)

{

  int16 idx;

  if(samplingFreq >= 92017L)                               idx = 0;

  else if(samplingFreq < 92017L && samplingFreq >= 75132L) idx = 1;

  else if(samplingFreq < 75132L && samplingFreq >= 55426)  idx = 2;

  else if(samplingFreq < 55426L && samplingFreq >= 46009L) idx = 3;

  else if(samplingFreq < 46009L && samplingFreq >= 37566L) idx = 4;

  else if(samplingFreq < 37566L && samplingFreq >= 27713L) idx = 5;

  else if(samplingFreq < 27713L && samplingFreq >= 23004L) idx = 6;

  else if(samplingFreq < 23004L && samplingFreq >= 18783L) idx = 7;

  else if(samplingFreq < 18783L && samplingFreq >= 13856L) idx = 8;

  else if(samplingFreq < 13856L && samplingFreq >= 11502L) idx = 9;

  else if(samplingFreq < 11502L && samplingFreq >= 9391L)  idx = 10;

  else                                                     idx = 11;

  return (idx);

}

/*

 * Reads GA decoder configuration information from the specified bitstream.

 */

static INLINE BOOL

ReadGASpecificInfo(TBitStream *bs, AudioSpecificInfo *audInfo, ProgConfig *progCfg)

{

  int16 extensionFlag;

  GaSpecificInfo *gaInfo = &audInfo->gaInfo;

  gaInfo->FrameLengthFlag = (BOOL) BsGetBits(bs, 1);

  gaInfo->DependsOnCoreCoder = (BOOL) BsGetBits(bs, 1);

  gaInfo->CoreCoderDelay = (gaInfo->DependsOnCoreCoder) ? (int16) BsGetBits(bs, 14) : (int16)0;

  extensionFlag = (int16) BsGetBits(bs, 1);

  if(audInfo->channelConfiguration == 0)

  {

    TInt numChans = 0;

    GetPCE(bs, progCfg, &numChans);

    audInfo->channelConfiguration = (uint8) numChans;

    if (audInfo->samplingFreqIdx != (uint8) progCfg->sample_rate_idx)

        {

        return FALSE;

        }

  }

  /*

   * Determine the sampling rate index so that sampling rate dependent

   * tables can be initialized.

   */

  if(audInfo->samplingFreqIdx == 0xf && audInfo->channelConfiguration != 0)

  {

    audInfo->samplingFreqIdx = (uint8) DetermineSamplingFreqIdx(audInfo->samplingFrequency);

    progCfg->sample_rate_idx = audInfo->samplingFreqIdx;

  }

  else

    {

    audInfo->samplingFreqIdx = (uint8) progCfg->sample_rate_idx;

    }

  if(audInfo->audioObject == AAC_SCALABLE || audInfo->audioObject == ER_AAC_SCALABLE)

    gaInfo->layerNr = (uint8) BsGetBits(bs, 3);

  if(extensionFlag)

  {

    if(audInfo->audioObject == ER_BSAC)

    {

      gaInfo->numOfSubframe = (uint8) BsGetBits(bs, 5);

      gaInfo->layer_length = (uint8) BsGetBits(bs, 11);

    }

    switch(audInfo->audioObject)

    {

      case ER_AAC_LC:

      case ER_AAC_LTP:

      case ER_AAC_SCALABLE:

      case ER_TWINVQ:

      case ER_AAC_LD:

        gaInfo->aacSectionDataResilienceFlag = (BOOL) BsGetBits(bs, 1);

        gaInfo->aacScalefactorDataResilienceFlag = (BOOL) BsGetBits(bs, 1);

        gaInfo->aacSpectralDataResilienceFlag = (BOOL) BsGetBits(bs, 1);

        break;

      default:

        break;

    }

    extensionFlag = (int16) BsGetBits(bs, 1);

    if(extensionFlag)

    {

      ;

    }

  }

  return TRUE;

}

/*

 * Reads MPEG-4 audio decoder specific configuration information.

 *

 * Retuns TRUE on success, FALSE otherwise. FALSE indicates that 

 * unsupported decoder configuration (e.g., object type) was detected.

 */

static INLINE BOOL

ReadAudioSpecificConfig(TBitStream *bs, AudioSpecificInfo *audInfo, 

            ProgConfig *progCfg, int32 bufLen)

{

  int16 bitsLeft;

  AudioObjectType audObj;

  /*-- Read common configuration information. --*/

  audObj = audInfo->audioObject = (AudioObjectType)(BsGetBits(bs, 5) - 1);

  audInfo->samplingFreqIdx = (uint8) BsGetBits(bs, 4);

  audInfo->samplingFrequency = sample_rates[audInfo->samplingFreqIdx];

  if(audInfo->samplingFreqIdx == 0xf)

    audInfo->samplingFrequency = (int32) BsGetBits(bs, 24);

  audInfo->channelConfiguration = (uint8) BsGetBits(bs, 4);

  audInfo->extAudioObject = (AudioObjectType) 0;

  audInfo->sbrPresentFlag = 0;

  if(audInfo->audioObject == AAC_SBR)

  {

    audInfo->extAudioObject = audInfo->audioObject;

    audInfo->sbrPresentFlag = 1;

    audInfo->extSamplingFreqIdx = (uint8) BsGetBits(bs, 4);

    if(audInfo->extSamplingFreqIdx == 0xf)

      audInfo->extSamplingFrequency = (int32) BsGetBits(bs, 24);

    audObj = audInfo->audioObject = (AudioObjectType)(BsGetBits(bs, 5) - 1);

  }

  /*-- Read object type specific configuration information. --*/

  switch(audInfo->audioObject)

  {

    case AAC_MAIN:

    case AAC_LC:

    case AAC_LTP:

      progCfg->profile = (int16) audObj;

      progCfg->sample_rate_idx = audInfo->samplingFreqIdx;

      if (ReadGASpecificInfo(bs, audInfo, progCfg) == FALSE)

        {

        return FALSE;

        }

      if(audInfo->samplingFreqIdx != 0xf)

        audInfo->samplingFrequency = sample_rates[audInfo->samplingFreqIdx];

      break;

    default:

      audObj = NULL_OBJECT;

      break;

  }

  bitsLeft = (int16) ((bufLen << 3) - BsGetBitsRead(bs));

  if(audInfo->extAudioObject != AAC_SBR && bitsLeft >= 16)

  {

    audInfo->syncExtensionType = (int16) BsGetBits(bs, 11);

    if(audInfo->syncExtensionType == 0x2b7)

    {

      audInfo->extAudioObject = (AudioObjectType)(BsGetBits(bs, 5) - 1);

      if(audInfo->extAudioObject == AAC_SBR)

      {

        audInfo->sbrPresentFlag = (uint8) BsGetBits(bs, 1);

        if(audInfo->sbrPresentFlag)

        {

          audInfo->extSamplingFreqIdx = (uint8) BsGetBits(bs, 4);

          if(audInfo->extSamplingFreqIdx == 0xf)

            audInfo->extSamplingFrequency = (int32) BsGetBits(bs, 24);

        }

      }

    }

  }

  return ((audObj == NULL_OBJECT) ? (BOOL) FALSE : (BOOL) TRUE);

}

BOOL

ReadMP4AudioConfig(uint8 *buffer, uint32 bufLen, mp4AACTransportHandle *mp4AAC_ff)

{

  TBitStream bs;

  BOOL retValue;

  BsInit(&bs, buffer, bufLen);

  retValue = ReadAudioSpecificConfig(&bs, &mp4AAC_ff->audioInfo, &mp4AAC_ff->progCfg, bufLen);

  return (retValue);

}

void

WriteMP4AudioConfig(uint8 *buffer, uint32 bufLen, mp4AACTransportHandle /* *mp4AAC_ff*/)

{

  TBitStream bs;

  BsInit(&bs, buffer, bufLen);

  /*-- Change object type to LC. --*/

  BsPutBits(&bs, 5, 2);

}