fdk-aac/libSBRenc/src/ps_main.cpp

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

© Copyright  1995 - 2018 Fraunhofer-Gesellschaft zur Förderung 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
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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.

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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
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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,
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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
----------------------------------------------------------------------------- */

/**************************** SBR encoder library ******************************

   Author(s):   M. Multrus

   Description: PS Wrapper, Downmix

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

#include "ps_main.h"

/* Includes ******************************************************************/
#include "ps_bitenc.h"
#include "sbrenc_ram.h"

/*--------------- function declarations --------------------*/
static void psFindBestScaling(
    HANDLE_PARAMETRIC_STEREO hParametricStereo,
    FIXP_DBL *hybridData[HYBRID_FRAMESIZE][MAX_PS_CHANNELS][2],
    UCHAR *dynBandScale, FIXP_DBL *maxBandValue, SCHAR *dmxScale);

/*------------- function definitions ----------------*/
FDK_PSENC_ERROR PSEnc_Create(HANDLE_PARAMETRIC_STEREO *phParametricStereo) {
  FDK_PSENC_ERROR error = PSENC_OK;
  HANDLE_PARAMETRIC_STEREO hParametricStereo = NULL;

  if (phParametricStereo == NULL) {
    error = PSENC_INVALID_HANDLE;
  } else {
    int i;

    if (NULL == (hParametricStereo = GetRam_ParamStereo())) {
      error = PSENC_MEMORY_ERROR;
      goto bail;
    }
    FDKmemclear(hParametricStereo, sizeof(PARAMETRIC_STEREO));

    if (PSENC_OK !=
        (error = FDKsbrEnc_CreatePSEncode(&hParametricStereo->hPsEncode))) {
      error = PSENC_MEMORY_ERROR;
      goto bail;
    }

    for (i = 0; i < MAX_PS_CHANNELS; i++) {
      if (FDKhybridAnalysisOpen(
              &hParametricStereo->fdkHybAnaFilter[i],
              hParametricStereo->__staticHybAnaStatesLF[i],
              sizeof(hParametricStereo->__staticHybAnaStatesLF[i]),
              hParametricStereo->__staticHybAnaStatesHF[i],
              sizeof(hParametricStereo->__staticHybAnaStatesHF[i])) != 0) {
        error = PSENC_MEMORY_ERROR;
        goto bail;
      }
    }
  }

bail:
  if (phParametricStereo != NULL) {
    *phParametricStereo = hParametricStereo; /* return allocated handle */
  }

  if (error != PSENC_OK) {
    PSEnc_Destroy(phParametricStereo);
  }
  return error;
}

FDK_PSENC_ERROR PSEnc_Init(HANDLE_PARAMETRIC_STEREO hParametricStereo,
                           const HANDLE_PSENC_CONFIG hPsEncConfig,
                           INT noQmfSlots, INT noQmfBands, UCHAR *dynamic_RAM) {
  FDK_PSENC_ERROR error = PSENC_OK;

  if ((NULL == hParametricStereo) || (NULL == hPsEncConfig)) {
    error = PSENC_INVALID_HANDLE;
  } else {
    int ch, i;

    hParametricStereo->initPS = 1;
    hParametricStereo->noQmfSlots = noQmfSlots;
    hParametricStereo->noQmfBands = noQmfBands;

    /* clear delay lines */
    FDKmemclear(hParametricStereo->qmfDelayLines,
                sizeof(hParametricStereo->qmfDelayLines));

    hParametricStereo->qmfDelayScale = FRACT_BITS - 1;

    /* create configuration for hybrid filter bank */
    for (ch = 0; ch < MAX_PS_CHANNELS; ch++) {
      FDKhybridAnalysisInit(&hParametricStereo->fdkHybAnaFilter[ch],
                            THREE_TO_TEN, 64, 64, 1);
    } /* ch */

    FDKhybridSynthesisInit(&hParametricStereo->fdkHybSynFilter, THREE_TO_TEN,
                           64, 64);

    /* determine average delay */
    hParametricStereo->psDelay =
        (HYBRID_FILTER_DELAY * hParametricStereo->noQmfBands);

    if ((hPsEncConfig->maxEnvelopes < PSENC_NENV_1) ||
        (hPsEncConfig->maxEnvelopes > PSENC_NENV_MAX)) {
      hPsEncConfig->maxEnvelopes = PSENC_NENV_DEFAULT;
    }
    hParametricStereo->maxEnvelopes = hPsEncConfig->maxEnvelopes;

    if (PSENC_OK !=
        (error = FDKsbrEnc_InitPSEncode(
             hParametricStereo->hPsEncode, (PS_BANDS)hPsEncConfig->nStereoBands,
             hPsEncConfig->iidQuantErrorThreshold))) {
      goto bail;
    }

    for (ch = 0; ch < MAX_PS_CHANNELS; ch++) {
      FIXP_DBL *pDynReal = GetRam_Sbr_envRBuffer(ch, dynamic_RAM);
      FIXP_DBL *pDynImag = GetRam_Sbr_envIBuffer(ch, dynamic_RAM);

      for (i = 0; i < HYBRID_FRAMESIZE; i++) {
        hParametricStereo->pHybridData[i + HYBRID_READ_OFFSET][ch][0] =
            &pDynReal[i * MAX_HYBRID_BANDS];
        hParametricStereo->pHybridData[i + HYBRID_READ_OFFSET][ch][1] =
            &pDynImag[i * MAX_HYBRID_BANDS];
        ;
      }

      for (i = 0; i < HYBRID_READ_OFFSET; i++) {
        hParametricStereo->pHybridData[i][ch][0] =
            hParametricStereo->__staticHybridData[i][ch][0];
        hParametricStereo->pHybridData[i][ch][1] =
            hParametricStereo->__staticHybridData[i][ch][1];
      }
    } /* ch */

    /* clear static hybrid buffer */
    FDKmemclear(hParametricStereo->__staticHybridData,
                sizeof(hParametricStereo->__staticHybridData));

    /* clear bs buffer */
    FDKmemclear(hParametricStereo->psOut, sizeof(hParametricStereo->psOut));

    hParametricStereo->psOut[0].enablePSHeader =
        1; /* write ps header in first frame */

    /* clear scaling buffer */
    FDKmemclear(hParametricStereo->dynBandScale, sizeof(UCHAR) * PS_MAX_BANDS);
    FDKmemclear(hParametricStereo->maxBandValue,
                sizeof(FIXP_DBL) * PS_MAX_BANDS);

  } /* valid handle */
bail:
  return error;
}

FDK_PSENC_ERROR PSEnc_Destroy(HANDLE_PARAMETRIC_STEREO *phParametricStereo) {
  FDK_PSENC_ERROR error = PSENC_OK;

  if (NULL != phParametricStereo) {
    HANDLE_PARAMETRIC_STEREO hParametricStereo = *phParametricStereo;
    if (hParametricStereo != NULL) {
      FDKsbrEnc_DestroyPSEncode(&hParametricStereo->hPsEncode);
      FreeRam_ParamStereo(phParametricStereo);
    }
  }

  return error;
}

static FDK_PSENC_ERROR ExtractPSParameters(
    HANDLE_PARAMETRIC_STEREO hParametricStereo, const int sendHeader,
    FIXP_DBL *hybridData[HYBRID_FRAMESIZE][MAX_PS_CHANNELS][2]) {
  FDK_PSENC_ERROR error = PSENC_OK;

  if (hParametricStereo == NULL) {
    error = PSENC_INVALID_HANDLE;
  } else {
    /* call ps encode function */
    if (hParametricStereo->initPS) {
      hParametricStereo->psOut[1] = hParametricStereo->psOut[0];
    }
    hParametricStereo->psOut[0] = hParametricStereo->psOut[1];

    if (PSENC_OK !=
        (error = FDKsbrEnc_PSEncode(
             hParametricStereo->hPsEncode, &hParametricStereo->psOut[1],
             hParametricStereo->dynBandScale, hParametricStereo->maxEnvelopes,
             hybridData, hParametricStereo->noQmfSlots, sendHeader))) {
      goto bail;
    }

    if (hParametricStereo->initPS) {
      hParametricStereo->psOut[0] = hParametricStereo->psOut[1];
      hParametricStereo->initPS = 0;
    }
  }
bail:
  return error;
}

static FDK_PSENC_ERROR DownmixPSQmfData(
    HANDLE_PARAMETRIC_STEREO hParametricStereo,
    HANDLE_QMF_FILTER_BANK sbrSynthQmf, FIXP_DBL **RESTRICT mixRealQmfData,
    FIXP_DBL **RESTRICT mixImagQmfData, INT_PCM *downsampledOutSignal,
    const UINT downsampledOutSignalBufSize,
    FIXP_DBL *hybridData[HYBRID_FRAMESIZE][MAX_PS_CHANNELS][2],
    const INT noQmfSlots, const INT psQmfScale[MAX_PS_CHANNELS],
    SCHAR *qmfScale) {
  FDK_PSENC_ERROR error = PSENC_OK;

  if (hParametricStereo == NULL) {
    error = PSENC_INVALID_HANDLE;
  } else {
    int n, k;
    C_AALLOC_SCRATCH_START(pWorkBuffer, FIXP_DBL, 2 * 64)

    /* define scalings */
    int dynQmfScale = fixMax(
        0, hParametricStereo->dmxScale -
               1); /* scale one bit more for addition of left and right */
    int downmixScale = psQmfScale[0] - dynQmfScale;
    const FIXP_DBL maxStereoScaleFactor = MAXVAL_DBL; /* 2.f/2.f */

    for (n = 0; n < noQmfSlots; n++) {
      FIXP_DBL tmpHybrid[2][MAX_HYBRID_BANDS];

      for (k = 0; k < 71; k++) {
        int dynScale, sc; /* scaling */
        FIXP_DBL tmpLeftReal, tmpRightReal, tmpLeftImag, tmpRightImag;
        FIXP_DBL tmpScaleFactor, stereoScaleFactor;

        tmpLeftReal = hybridData[n][0][0][k];
        tmpLeftImag = hybridData[n][0][1][k];
        tmpRightReal = hybridData[n][1][0][k];
        tmpRightImag = hybridData[n][1][1][k];

        sc = fixMax(
            0, CntLeadingZeros(fixMax(
                   fixMax(fixp_abs(tmpLeftReal), fixp_abs(tmpLeftImag)),
                   fixMax(fixp_abs(tmpRightReal), fixp_abs(tmpRightImag)))) -
                   2);

        tmpLeftReal <<= sc;
        tmpLeftImag <<= sc;
        tmpRightReal <<= sc;
        tmpRightImag <<= sc;
        dynScale = fixMin(sc - dynQmfScale, DFRACT_BITS - 1);

        /* calc stereo scale factor to avoid loss of energy in bands */
        /* stereo scale factor = min(2.0f, sqrt( (abs(l(k, n)^2 + abs(r(k, n)^2
         * )))/(0.5f*abs(l(k, n) + r(k, n))) )) */
        stereoScaleFactor = fPow2Div2(tmpLeftReal) + fPow2Div2(tmpLeftImag) +
                            fPow2Div2(tmpRightReal) + fPow2Div2(tmpRightImag);

        /* might be that tmpScaleFactor becomes negative, so fabs(.) */
        tmpScaleFactor =
            fixp_abs(stereoScaleFactor + fMult(tmpLeftReal, tmpRightReal) +
                     fMult(tmpLeftImag, tmpRightImag));

        /* min(2.0f, sqrt(stereoScaleFactor/(0.5f*tmpScaleFactor)))  */
        if ((stereoScaleFactor >> 1) <
            fMult(maxStereoScaleFactor, tmpScaleFactor)) {
          int sc_num = CountLeadingBits(stereoScaleFactor);
          int sc_denum = CountLeadingBits(tmpScaleFactor);
          sc = -(sc_num - sc_denum);

          tmpScaleFactor = schur_div((stereoScaleFactor << (sc_num)) >> 1,
                                     tmpScaleFactor << sc_denum, 16);

          /* prevent odd scaling for next sqrt calculation */
          if (sc & 0x1) {
            sc++;
            tmpScaleFactor >>= 1;
          }
          stereoScaleFactor = sqrtFixp(tmpScaleFactor);
          stereoScaleFactor <<= (sc >> 1);
        } else {
          stereoScaleFactor = maxStereoScaleFactor;
        }

        /* write data to hybrid output */
        tmpHybrid[0][k] = fMultDiv2(stereoScaleFactor,
                                    (FIXP_DBL)(tmpLeftReal + tmpRightReal)) >>
                          dynScale;
        tmpHybrid[1][k] = fMultDiv2(stereoScaleFactor,
                                    (FIXP_DBL)(tmpLeftImag + tmpRightImag)) >>
                          dynScale;

      } /* hybrid bands - k */

      FDKhybridSynthesisApply(&hParametricStereo->fdkHybSynFilter, tmpHybrid[0],
                              tmpHybrid[1], mixRealQmfData[n],
                              mixImagQmfData[n]);

      qmfSynthesisFilteringSlot(
          sbrSynthQmf, mixRealQmfData[n], mixImagQmfData[n], downmixScale - 7,
          downmixScale - 7,
          downsampledOutSignal + (n * sbrSynthQmf->no_channels), 1,
          pWorkBuffer);

    } /* slots */

    *qmfScale = -downmixScale + 7;

    C_AALLOC_SCRATCH_END(pWorkBuffer, FIXP_DBL, 2 * 64)

    {
      const INT noQmfSlots2 = hParametricStereo->noQmfSlots >> 1;
      const int noQmfBands = hParametricStereo->noQmfBands;

      INT scale, i, j, slotOffset;

      FIXP_DBL tmp[2][64];

      for (i = 0; i < noQmfSlots2; i++) {
        FDKmemcpy(tmp[0], hParametricStereo->qmfDelayLines[0][i],
                  noQmfBands * sizeof(FIXP_DBL));
        FDKmemcpy(tmp[1], hParametricStereo->qmfDelayLines[1][i],
                  noQmfBands * sizeof(FIXP_DBL));

        FDKmemcpy(hParametricStereo->qmfDelayLines[0][i],
                  mixRealQmfData[i + noQmfSlots2],
                  noQmfBands * sizeof(FIXP_DBL));
        FDKmemcpy(hParametricStereo->qmfDelayLines[1][i],
                  mixImagQmfData[i + noQmfSlots2],
                  noQmfBands * sizeof(FIXP_DBL));

        FDKmemcpy(mixRealQmfData[i + noQmfSlots2], mixRealQmfData[i],
                  noQmfBands * sizeof(FIXP_DBL));
        FDKmemcpy(mixImagQmfData[i + noQmfSlots2], mixImagQmfData[i],
                  noQmfBands * sizeof(FIXP_DBL));

        FDKmemcpy(mixRealQmfData[i], tmp[0], noQmfBands * sizeof(FIXP_DBL));
        FDKmemcpy(mixImagQmfData[i], tmp[1], noQmfBands * sizeof(FIXP_DBL));
      }

      if (hParametricStereo->qmfDelayScale > *qmfScale) {
        scale = hParametricStereo->qmfDelayScale - *qmfScale;
        slotOffset = 0;
      } else {
        scale = *qmfScale - hParametricStereo->qmfDelayScale;
        slotOffset = noQmfSlots2;
      }

      for (i = 0; i < noQmfSlots2; i++) {
        for (j = 0; j < noQmfBands; j++) {
          mixRealQmfData[i + slotOffset][j] >>= scale;
          mixImagQmfData[i + slotOffset][j] >>= scale;
        }
      }

      scale = *qmfScale;
      *qmfScale = fMin(*qmfScale, hParametricStereo->qmfDelayScale);
      hParametricStereo->qmfDelayScale = scale;
    }

  } /* valid handle */

  return error;
}

INT FDKsbrEnc_PSEnc_WritePSData(HANDLE_PARAMETRIC_STEREO hParametricStereo,
                                HANDLE_FDK_BITSTREAM hBitstream) {
  return (
      (hParametricStereo != NULL)
          ? FDKsbrEnc_WritePSBitstream(&hParametricStereo->psOut[0], hBitstream)
          : 0);
}

FDK_PSENC_ERROR FDKsbrEnc_PSEnc_ParametricStereoProcessing(
    HANDLE_PARAMETRIC_STEREO hParametricStereo, INT_PCM *samples[2],
    UINT samplesBufSize, QMF_FILTER_BANK **hQmfAnalysis,
    FIXP_DBL **RESTRICT downmixedRealQmfData,
    FIXP_DBL **RESTRICT downmixedImagQmfData, INT_PCM *downsampledOutSignal,
    HANDLE_QMF_FILTER_BANK sbrSynthQmf, SCHAR *qmfScale, const int sendHeader) {
  FDK_PSENC_ERROR error = PSENC_OK;
  INT psQmfScale[MAX_PS_CHANNELS] = {0};
  int psCh, i;
  C_AALLOC_SCRATCH_START(pWorkBuffer, FIXP_DBL, 4 * 64)

  for (psCh = 0; psCh < MAX_PS_CHANNELS; psCh++) {
    for (i = 0; i < hQmfAnalysis[psCh]->no_col; i++) {
      qmfAnalysisFilteringSlot(
          hQmfAnalysis[psCh], &pWorkBuffer[2 * 64], /* qmfReal[64] */
          &pWorkBuffer[3 * 64],                     /* qmfImag[64] */
          samples[psCh] + i * hQmfAnalysis[psCh]->no_channels, 1,
          &pWorkBuffer[0 * 64] /* qmf workbuffer 2*64 */
      );

      FDKhybridAnalysisApply(
          &hParametricStereo->fdkHybAnaFilter[psCh],
          &pWorkBuffer[2 * 64], /* qmfReal[64] */
          &pWorkBuffer[3 * 64], /* qmfImag[64] */
          hParametricStereo->pHybridData[i + HYBRID_READ_OFFSET][psCh][0],
          hParametricStereo->pHybridData[i + HYBRID_READ_OFFSET][psCh][1]);

    } /* no_col loop  i  */

    psQmfScale[psCh] = hQmfAnalysis[psCh]->outScalefactor;

  } /* for psCh */

  C_AALLOC_SCRATCH_END(pWorkBuffer, FIXP_DBL, 4 * 64)

  /* find best scaling in new QMF and Hybrid data */
  psFindBestScaling(
      hParametricStereo, &hParametricStereo->pHybridData[HYBRID_READ_OFFSET],
      hParametricStereo->dynBandScale, hParametricStereo->maxBandValue,
      &hParametricStereo->dmxScale);

  /* extract the ps parameters */
  if (PSENC_OK !=
      (error = ExtractPSParameters(hParametricStereo, sendHeader,
                                   &hParametricStereo->pHybridData[0]))) {
    goto bail;
  }

  /* save hybrid date for next frame */
  for (i = 0; i < HYBRID_READ_OFFSET; i++) {
    FDKmemcpy(
        hParametricStereo->pHybridData[i][0][0],
        hParametricStereo->pHybridData[hParametricStereo->noQmfSlots + i][0][0],
        MAX_HYBRID_BANDS * sizeof(FIXP_DBL)); /* left, real */
    FDKmemcpy(
        hParametricStereo->pHybridData[i][0][1],
        hParametricStereo->pHybridData[hParametricStereo->noQmfSlots + i][0][1],
        MAX_HYBRID_BANDS * sizeof(FIXP_DBL)); /* left, imag */
    FDKmemcpy(
        hParametricStereo->pHybridData[i][1][0],
        hParametricStereo->pHybridData[hParametricStereo->noQmfSlots + i][1][0],
        MAX_HYBRID_BANDS * sizeof(FIXP_DBL)); /* right, real */
    FDKmemcpy(
        hParametricStereo->pHybridData[i][1][1],
        hParametricStereo->pHybridData[hParametricStereo->noQmfSlots + i][1][1],
        MAX_HYBRID_BANDS * sizeof(FIXP_DBL)); /* right, imag */
  }

  /* downmix and hybrid synthesis */
  if (PSENC_OK !=
      (error = DownmixPSQmfData(
           hParametricStereo, sbrSynthQmf, downmixedRealQmfData,
           downmixedImagQmfData, downsampledOutSignal, samplesBufSize,
           &hParametricStereo->pHybridData[HYBRID_READ_OFFSET],
           hParametricStereo->noQmfSlots, psQmfScale, qmfScale))) {
    goto bail;
  }

bail:

  return error;
}

static void psFindBestScaling(
    HANDLE_PARAMETRIC_STEREO hParametricStereo,
    FIXP_DBL *hybridData[HYBRID_FRAMESIZE][MAX_PS_CHANNELS][2],
    UCHAR *dynBandScale, FIXP_DBL *maxBandValue, SCHAR *dmxScale) {
  HANDLE_PS_ENCODE hPsEncode = hParametricStereo->hPsEncode;

  INT group, bin, col, band;
  const INT frameSize = hParametricStereo->noQmfSlots;
  const INT psBands = (INT)hPsEncode->psEncMode;
  const INT nIidGroups = hPsEncode->nQmfIidGroups + hPsEncode->nSubQmfIidGroups;

  /* group wise scaling */
  FIXP_DBL maxVal[2][PS_MAX_BANDS];
  FIXP_DBL maxValue = FL2FXCONST_DBL(0.f);

  FDKmemclear(maxVal, sizeof(maxVal));

  /* start with hybrid data */
  for (group = 0; group < nIidGroups; group++) {
    /* Translate group to bin */
    bin = hPsEncode->subband2parameterIndex[group];

    /* Translate from 20 bins to 10 bins */
    if (hPsEncode->psEncMode == PS_BANDS_COARSE) {
      bin >>= 1;
    }

    /* QMF downmix scaling */
    for (col = 0; col < frameSize; col++) {
      int i, section = (col < frameSize - HYBRID_READ_OFFSET) ? 0 : 1;
      FIXP_DBL tmp = maxVal[section][bin];
      for (i = hPsEncode->iidGroupBorders[group];
           i < hPsEncode->iidGroupBorders[group + 1]; i++) {
        tmp = fixMax(tmp, (FIXP_DBL)fixp_abs(hybridData[col][0][0][i]));
        tmp = fixMax(tmp, (FIXP_DBL)fixp_abs(hybridData[col][0][1][i]));
        tmp = fixMax(tmp, (FIXP_DBL)fixp_abs(hybridData[col][1][0][i]));
        tmp = fixMax(tmp, (FIXP_DBL)fixp_abs(hybridData[col][1][1][i]));
      }
      maxVal[section][bin] = tmp;
    }
  } /* nIidGroups */

  /* convert maxSpec to maxScaling, find scaling space */
  for (band = 0; band < psBands; band++) {
#ifndef MULT_16x16
    dynBandScale[band] =
        CountLeadingBits(fixMax(maxVal[0][band], maxBandValue[band]));
#else
    dynBandScale[band] = fixMax(
        0, CountLeadingBits(fixMax(maxVal[0][band], maxBandValue[band])) -
               FRACT_BITS);
#endif
    maxValue = fixMax(maxValue, fixMax(maxVal[0][band], maxVal[1][band]));
    maxBandValue[band] = fixMax(maxVal[0][band], maxVal[1][band]);
  }

    /* calculate maximal scaling for QMF downmix */
#ifndef MULT_16x16
  *dmxScale = fixMin(DFRACT_BITS, CountLeadingBits(maxValue));
#else
  *dmxScale = fixMax(0, fixMin(FRACT_BITS, CountLeadingBits((maxValue))));
#endif
}