fdk-aac/libDRCdec/src/drcDec_gainDecoder.cpp

/* -----------------------------------------------------------------------------
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----------------------------------------------------------------------------- */

/************************* MPEG-D DRC decoder library **************************

   Author(s):

   Description:

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

#include "drcDec_types.h"
#include "drcDec_gainDecoder.h"
#include "drcGainDec_preprocess.h"
#include "drcGainDec_init.h"
#include "drcGainDec_process.h"
#include "drcDec_tools.h"

/*******************************************/
/* static functions                        */
/*******************************************/

static int _fitsLocation(DRC_INSTRUCTIONS_UNI_DRC* pInst,
                         const GAIN_DEC_LOCATION drcLocation) {
  int downmixId = pInst->drcApplyToDownmix ? pInst->downmixId[0] : 0;
  switch (drcLocation) {
    case GAIN_DEC_DRC1:
      return (downmixId == 0);
    case GAIN_DEC_DRC1_DRC2:
      return ((downmixId == 0) || (downmixId == DOWNMIX_ID_ANY_DOWNMIX));
    case GAIN_DEC_DRC2:
      return (downmixId == DOWNMIX_ID_ANY_DOWNMIX);
    case GAIN_DEC_DRC3:
      return ((downmixId != 0) && (downmixId != DOWNMIX_ID_ANY_DOWNMIX));
    case GAIN_DEC_DRC2_DRC3:
      return (downmixId != 0);
  }
  return 0;
}

static void _setChannelGains(HANDLE_DRC_GAIN_DECODER hGainDec,
                             const int numChannelGains,
                             const FIXP_DBL* channelGainDb) {
  int i, channelGain_e;
  FIXP_DBL channelGain;
  FDK_ASSERT(numChannelGains <= 8);
  for (i = 0; i < numChannelGains; i++) {
    if (channelGainDb[i] == (FIXP_DBL)MINVAL_DBL) {
      hGainDec->channelGain[i] = (FIXP_DBL)0;
    } else {
      /* add loudness normalisation gain (dB) to channel gain (dB) */
      FIXP_DBL tmp_channelGainDb = (channelGainDb[i] >> 1) +
                                   (hGainDec->loudnessNormalisationGainDb >> 2);
      tmp_channelGainDb =
          SATURATE_LEFT_SHIFT(tmp_channelGainDb, 1, DFRACT_BITS);
      channelGain = dB2lin(tmp_channelGainDb, 8, &channelGain_e);
      hGainDec->channelGain[i] = scaleValue(channelGain, channelGain_e - 8);
    }
  }
}

/*******************************************/
/* public functions                        */
/*******************************************/

DRC_ERROR
drcDec_GainDecoder_Open(HANDLE_DRC_GAIN_DECODER* phGainDec) {
  DRC_GAIN_DECODER* hGainDec = NULL;

  hGainDec = (DRC_GAIN_DECODER*)FDKcalloc(1, sizeof(DRC_GAIN_DECODER));
  if (hGainDec == NULL) return DE_MEMORY_ERROR;

  hGainDec->multiBandActiveDrcIndex = -1;
  hGainDec->channelGainActiveDrcIndex = -1;

  *phGainDec = hGainDec;

  return DE_OK;
}

DRC_ERROR
drcDec_GainDecoder_Init(HANDLE_DRC_GAIN_DECODER hGainDec, const int frameSize,
                        const int sampleRate) {
  DRC_ERROR err = DE_OK;

  err = initGainDec(hGainDec, frameSize, sampleRate);
  if (err) return err;

  initDrcGainBuffers(hGainDec->frameSize, &hGainDec->drcGainBuffers);

  return err;
}

DRC_ERROR
drcDec_GainDecoder_SetCodecDependentParameters(
    HANDLE_DRC_GAIN_DECODER hGainDec, const DELAY_MODE delayMode,
    const int timeDomainSupported,
    const SUBBAND_DOMAIN_MODE subbandDomainSupported) {
  if ((delayMode != DM_REGULAR_DELAY) && (delayMode != DM_LOW_DELAY)) {
    return DE_NOT_OK;
  }
  hGainDec->delayMode = delayMode;
  hGainDec->timeDomainSupported = timeDomainSupported;
  hGainDec->subbandDomainSupported = subbandDomainSupported;

  return DE_OK;
}

DRC_ERROR
drcDec_GainDecoder_Config(HANDLE_DRC_GAIN_DECODER hGainDec,
                          HANDLE_UNI_DRC_CONFIG hUniDrcConfig,
                          const UCHAR numSelectedDrcSets,
                          const SCHAR* selectedDrcSetIds,
                          const UCHAR* selectedDownmixIds) {
  DRC_ERROR err = DE_OK;
  int a;

  hGainDec->nActiveDrcs = 0;
  hGainDec->multiBandActiveDrcIndex = -1;
  hGainDec->channelGainActiveDrcIndex = -1;
  for (a = 0; a < numSelectedDrcSets; a++) {
    err = initActiveDrc(hGainDec, hUniDrcConfig, selectedDrcSetIds[a],
                        selectedDownmixIds[a]);
    if (err) return err;
  }

  err = initActiveDrcOffset(hGainDec);
  if (err) return err;

  return err;
}

DRC_ERROR
drcDec_GainDecoder_Close(HANDLE_DRC_GAIN_DECODER* phGainDec) {
  if (*phGainDec != NULL) {
    FDKfree(*phGainDec);
    *phGainDec = NULL;
  }

  return DE_OK;
}

DRC_ERROR
drcDec_GainDecoder_Preprocess(HANDLE_DRC_GAIN_DECODER hGainDec,
                              HANDLE_UNI_DRC_GAIN hUniDrcGain,
                              const FIXP_DBL loudnessNormalizationGainDb,
                              const FIXP_SGL boost, const FIXP_SGL compress) {
  DRC_ERROR err = DE_OK;
  int a, c;

  /* lnbPointer is the index on the most recent node buffer */
  hGainDec->drcGainBuffers.lnbPointer++;
  if (hGainDec->drcGainBuffers.lnbPointer >= NUM_LNB_FRAMES)
    hGainDec->drcGainBuffers.lnbPointer = 0;

  for (a = 0; a < hGainDec->nActiveDrcs; a++) {
    /* prepare gain interpolation of sequences used by copying and modifying
     * nodes in node buffers */
    err = prepareDrcGain(hGainDec, hUniDrcGain, compress, boost,
                         loudnessNormalizationGainDb, a);
    if (err) return err;
  }

  for (a = 0; a < MAX_ACTIVE_DRCS; a++) {
    for (c = 0; c < 8; c++) {
      hGainDec->activeDrc[a]
          .lnbIndexForChannel[c][hGainDec->drcGainBuffers.lnbPointer] =
          -1; /* "no DRC processing" */
    }
    hGainDec->activeDrc[a].subbandGainsReady = 0;
  }

  for (c = 0; c < 8; c++) {
    hGainDec->drcGainBuffers
        .channelGain[c][hGainDec->drcGainBuffers.lnbPointer] =
        FL2FXCONST_DBL(1.0f / (float)(1 << 8));
  }

  return err;
}

/* create gain sequence out of gain sequences of last frame for concealment and
 * flushing */
DRC_ERROR
drcDec_GainDecoder_Conceal(HANDLE_DRC_GAIN_DECODER hGainDec,
                           HANDLE_UNI_DRC_CONFIG hUniDrcConfig,
                           HANDLE_UNI_DRC_GAIN hUniDrcGain) {
  int seq, gainSequenceCount;
  DRC_COEFFICIENTS_UNI_DRC* pCoef =
      selectDrcCoefficients(hUniDrcConfig, LOCATION_SELECTED);
  if (pCoef == NULL) return DE_OK;

  gainSequenceCount = fMin(pCoef->gainSequenceCount, (UCHAR)12);

  for (seq = 0; seq < gainSequenceCount; seq++) {
    int lastNodeIndex = 0;
    FIXP_SGL lastGainDb = (FIXP_SGL)0;

    lastNodeIndex = hUniDrcGain->nNodes[seq] - 1;
    if ((lastNodeIndex >= 0) && (lastNodeIndex < 16)) {
      lastGainDb = hUniDrcGain->gainNode[seq][lastNodeIndex].gainDb;
    }

    hUniDrcGain->nNodes[seq] = 1;
    if (lastGainDb > (FIXP_SGL)0) {
      hUniDrcGain->gainNode[seq][0].gainDb =
          FX_DBL2FX_SGL(fMult(FL2FXCONST_SGL(0.9f), lastGainDb));
    } else {
      hUniDrcGain->gainNode[seq][0].gainDb =
          FX_DBL2FX_SGL(fMult(FL2FXCONST_SGL(0.98f), lastGainDb));
    }
    hUniDrcGain->gainNode[seq][0].time = hGainDec->frameSize - 1;
  }
  return DE_OK;
}

void drcDec_GainDecoder_SetChannelGains(HANDLE_DRC_GAIN_DECODER hGainDec,
                                        const int numChannels,
                                        const int frameSize,
                                        const FIXP_DBL* channelGainDb,
                                        const int audioBufferChannelOffset,
                                        FIXP_DBL* audioBuffer) {
  int c, i;

  if (hGainDec->channelGainActiveDrcIndex >= 0) {
    /* channel gains will be applied in drcDec_GainDecoder_ProcessTimeDomain or
     * drcDec_GainDecoder_ProcessSubbandDomain, respectively. */
    _setChannelGains(hGainDec, numChannels, channelGainDb);

    if (!hGainDec->status) { /* overwrite previous channel gains at startup */
      DRC_GAIN_BUFFERS* pDrcGainBuffers = &hGainDec->drcGainBuffers;
      for (c = 0; c < numChannels; c++) {
        for (i = 0; i < NUM_LNB_FRAMES; i++) {
          pDrcGainBuffers->channelGain[c][i] = hGainDec->channelGain[c];
        }
      }
      hGainDec->status = 1;
    }
  } else {
    /* smooth and apply channel gains */
    FIXP_DBL prevChannelGain[8];
    for (c = 0; c < numChannels; c++) {
      prevChannelGain[c] = hGainDec->channelGain[c];
    }

    _setChannelGains(hGainDec, numChannels, channelGainDb);

    if (!hGainDec->status) { /* overwrite previous channel gains at startup */
      for (c = 0; c < numChannels; c++)
        prevChannelGain[c] = hGainDec->channelGain[c];
      hGainDec->status = 1;
    }

    for (c = 0; c < numChannels; c++) {
      INT n_min = fMin(fMin(CntLeadingZeros(prevChannelGain[c]),
                            CntLeadingZeros(hGainDec->channelGain[c])) -
                           1,
                       9);
      FIXP_DBL gain = prevChannelGain[c] << n_min;
      FIXP_DBL stepsize = ((hGainDec->channelGain[c] << n_min) - gain);
      if (stepsize != (FIXP_DBL)0) {
        if (frameSize == 1024)
          stepsize = stepsize >> 10;
        else
          stepsize = (LONG)stepsize / frameSize;
      }
      n_min = 9 - n_min;
#ifdef FUNCTION_drcDec_GainDecoder_SetChannelGains_func1
      drcDec_GainDecoder_SetChannelGains_func1(audioBuffer, gain, stepsize,
                                               n_min, frameSize);
#else
      for (i = 0; i < frameSize; i++) {
        audioBuffer[i] = fMultDiv2(audioBuffer[i], gain) << n_min;
        gain += stepsize;
      }
#endif
      audioBuffer += audioBufferChannelOffset;
    }
  }
}

DRC_ERROR
drcDec_GainDecoder_ProcessTimeDomain(
    HANDLE_DRC_GAIN_DECODER hGainDec, const int delaySamples,
    const GAIN_DEC_LOCATION drcLocation, const int channelOffset,
    const int drcChannelOffset, const int numChannelsProcessed,
    const int timeDataChannelOffset, FIXP_DBL* audioIOBuffer) {
  DRC_ERROR err = DE_OK;
  int a;

  if (!hGainDec->timeDomainSupported) {
    return DE_NOT_OK;
  }

  for (a = 0; a < hGainDec->nActiveDrcs; a++) {
    if (!_fitsLocation(hGainDec->activeDrc[a].pInst, drcLocation)) continue;

    /* Apply DRC */
    err = processDrcTime(hGainDec, a, delaySamples, channelOffset,
                         drcChannelOffset, numChannelsProcessed,
                         timeDataChannelOffset, audioIOBuffer);
    if (err) return err;
  }

  return err;
}

DRC_ERROR
drcDec_GainDecoder_ProcessSubbandDomain(
    HANDLE_DRC_GAIN_DECODER hGainDec, const int delaySamples,
    const GAIN_DEC_LOCATION drcLocation, const int channelOffset,
    const int drcChannelOffset, const int numChannelsProcessed,
    const int processSingleTimeslot, FIXP_DBL* audioIOBufferReal[],
    FIXP_DBL* audioIOBufferImag[]) {
  DRC_ERROR err = DE_OK;
  int a;

  if (hGainDec->subbandDomainSupported == SDM_OFF) {
    return DE_NOT_OK;
  }

  for (a = 0; a < hGainDec->nActiveDrcs; a++) {
    if (!_fitsLocation(hGainDec->activeDrc[a].pInst, drcLocation)) continue;

    /* Apply DRC */
    err = processDrcSubband(hGainDec, a, delaySamples, channelOffset,
                            drcChannelOffset, numChannelsProcessed,
                            processSingleTimeslot, audioIOBufferReal,
                            audioIOBufferImag);
    if (err) return err;
  }

  return err;
}

DRC_ERROR
drcDec_GainDecoder_SetLoudnessNormalizationGainDb(
    HANDLE_DRC_GAIN_DECODER hGainDec, FIXP_DBL loudnessNormalizationGainDb) {
  hGainDec->loudnessNormalisationGainDb = loudnessNormalizationGainDb;

  return DE_OK;
}

int drcDec_GainDecoder_GetFrameSize(HANDLE_DRC_GAIN_DECODER hGainDec) {
  if (hGainDec == NULL) return -1;

  return hGainDec->frameSize;
}

int drcDec_GainDecoder_GetDeltaTminDefault(HANDLE_DRC_GAIN_DECODER hGainDec) {
  if (hGainDec == NULL) return -1;

  return hGainDec->deltaTminDefault;
}