path: root/libAACenc/src/metadata_compressor.cpp

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

© Copyright  1995 - 2013 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 (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
----------------------------------------------------------------------------------------------------------- */

/**********************  Fraunhofer IIS FDK AAC Encoder lib  ******************

   Author(s): M. Neusinger
   Description: Compressor for AAC Metadata Generator

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


#include "metadata_compressor.h"
#include "channel_map.h"


#define LOG2                                    0.69314718056f  /* natural logarithm of 2 */
#define ILOG2                                   1.442695041f    /* 1/LOG2 */
#define FIXP_ILOG2_DIV2                         (FL2FXCONST_DBL(ILOG2/2))

/*----------------- defines ----------------------*/

#define MAX_DRC_CHANNELS        (8)          /*!< Max number of audio input channels. */
#define DOWNMIX_SHIFT           (3)          /*!< Max 8 channel. */
#define WEIGHTING_FILTER_SHIFT  (2)          /*!< Scaling used in weighting filter. */

#define METADATA_INT_BITS      10
#define METADATA_LINT_BITS     20
#define METADATA_INT_SCALE     (INT64(1)<<(METADATA_INT_BITS))
#define METADATA_FRACT_BITS    (DFRACT_BITS-1-METADATA_INT_BITS)
#define METADATA_FRACT_SCALE   (INT64(1)<<(METADATA_FRACT_BITS))

/**
 *  Enum for channel assignment.
 */
enum {
    L   = 0,
    R   = 1,
    C   = 2,
    LFE = 3,
    LS  = 4,
    RS  = 5,
    S   = 6,
    LS2 = 7,
    RS2 = 8
};

/*--------------- structure definitions --------------------*/

/**
 *  Structure holds weighting filter filter states.
 */
struct WEIGHTING_STATES {
    FIXP_DBL x1;
    FIXP_DBL x2;
    FIXP_DBL y1;
    FIXP_DBL y2;
};

/**
 *  Dynamic Range Control compressor structure.
 */
struct DRC_COMP {

    FIXP_DBL     maxBoostThr[2];             /*!< Max boost threshold. */
    FIXP_DBL     boostThr[2];                /*!< Boost threshold. */
    FIXP_DBL     earlyCutThr[2];             /*!< Early cut threshold. */
    FIXP_DBL     cutThr[2];                  /*!< Cut threshold. */
    FIXP_DBL     maxCutThr[2];               /*!< Max cut threshold. */

    FIXP_DBL     boostFac[2];                /*!< Precalculated factor for boost compression. */
    FIXP_DBL     earlyCutFac[2];             /*!< Precalculated factor for early cut compression. */
    FIXP_DBL     cutFac[2];                  /*!< Precalculated factor for cut compression. */

    FIXP_DBL     maxBoost[2];                /*!< Maximum boost. */
    FIXP_DBL     maxCut[2];                  /*!< Maximum cut. */
    FIXP_DBL     maxEarlyCut[2];             /*!< Maximum early cut. */

    FIXP_DBL     fastAttack[2];              /*!< Fast attack coefficient. */
    FIXP_DBL     fastDecay[2];               /*!< Fast release coefficient. */
    FIXP_DBL     slowAttack[2];              /*!< Slow attack coefficient. */
    FIXP_DBL     slowDecay[2];               /*!< Slow release coefficient. */
    UINT         holdOff[2];                 /*!< Hold time in blocks. */

    FIXP_DBL     attackThr[2];               /*!< Slow/fast attack threshold. */
    FIXP_DBL     decayThr[2];                /*!< Slow/fast release threshold. */

    DRC_PROFILE  profile[2];                 /*!< DRC profile. */
    INT          blockLength;                /*!< Block length in samples. */
    UINT         sampleRate;                 /*!< Sample rate. */
    CHANNEL_MODE chanConfig;                 /*!< Channel configuration. */

    UCHAR        useWeighting;               /*!< Use weighting filter. */

    UINT         channels;                   /*!< Number of channels. */
    UINT         fullChannels;               /*!< Number of full range channels. */
    INT          channelIdx[9];              /*!< Offsets of interleaved channel samples (L, R, C, LFE, Ls, Rs, S, Ls2, Rs2). */

    FIXP_DBL     smoothLevel[2];             /*!< level smoothing states */
    FIXP_DBL     smoothGain[2];              /*!< gain smoothing states */
    UINT         holdCnt[2];                 /*!< hold counter */

    FIXP_DBL     limGain[2];                 /*!< limiter gain */
    FIXP_DBL     limDecay;                   /*!< limiter decay (linear) */
    FIXP_DBL     prevPeak[2];                /*!< max peak of previous block (stereo/mono)*/

    WEIGHTING_STATES filter[MAX_DRC_CHANNELS]; /*!< array holds weighting filter states */

};

/*---------------- constants -----------------------*/

/**
 *  Profile tables.
 */
static const FIXP_DBL tabMaxBoostThr[] = {
    (FIXP_DBL)(-43<<METADATA_FRACT_BITS),
    (FIXP_DBL)(-53<<METADATA_FRACT_BITS),
    (FIXP_DBL)(-55<<METADATA_FRACT_BITS),
    (FIXP_DBL)(-65<<METADATA_FRACT_BITS),
    (FIXP_DBL)(-50<<METADATA_FRACT_BITS),
    (FIXP_DBL)(-40<<METADATA_FRACT_BITS)
};
static const FIXP_DBL tabBoostThr[] = {
    (FIXP_DBL)(-31<<METADATA_FRACT_BITS),
    (FIXP_DBL)(-41<<METADATA_FRACT_BITS),
    (FIXP_DBL)(-31<<METADATA_FRACT_BITS),
    (FIXP_DBL)(-41<<METADATA_FRACT_BITS),
    (FIXP_DBL)(-31<<METADATA_FRACT_BITS),
    (FIXP_DBL)(-31<<METADATA_FRACT_BITS)
};
static const FIXP_DBL tabEarlyCutThr[] = {
    (FIXP_DBL)(-26<<METADATA_FRACT_BITS),
    (FIXP_DBL)(-21<<METADATA_FRACT_BITS),
    (FIXP_DBL)(-26<<METADATA_FRACT_BITS),
    (FIXP_DBL)(-21<<METADATA_FRACT_BITS),
    (FIXP_DBL)(-26<<METADATA_FRACT_BITS),
    (FIXP_DBL)(-20<<METADATA_FRACT_BITS)
};
static const FIXP_DBL tabCutThr[]      = {
    (FIXP_DBL)(-16<<METADATA_FRACT_BITS),
    (FIXP_DBL)(-11<<METADATA_FRACT_BITS),
    (FIXP_DBL)(-16<<METADATA_FRACT_BITS),
    (FIXP_DBL)(-21<<METADATA_FRACT_BITS),
    (FIXP_DBL)(-16<<METADATA_FRACT_BITS),
    (FIXP_DBL)(-10<<METADATA_FRACT_BITS)
};
static const FIXP_DBL tabMaxCutThr[]   = {
    (FIXP_DBL)(4<<METADATA_FRACT_BITS),
    (FIXP_DBL)(9<<METADATA_FRACT_BITS),
    (FIXP_DBL)(4<<METADATA_FRACT_BITS),
    (FIXP_DBL)(9<<METADATA_FRACT_BITS),
    (FIXP_DBL)(4<<METADATA_FRACT_BITS),
    (FIXP_DBL)(4<<METADATA_FRACT_BITS)
};
static const FIXP_DBL tabBoostRatio[] = {
    FL2FXCONST_DBL( ((1.f/2.f) - 1.f) ),
    FL2FXCONST_DBL( ((1.f/2.f) - 1.f) ),
    FL2FXCONST_DBL( ((1.f/2.f) - 1.f) ),
    FL2FXCONST_DBL( ((1.f/2.f) - 1.f) ),
    FL2FXCONST_DBL( ((1.f/5.f) - 1.f) ),
    FL2FXCONST_DBL( ((1.f/5.f) - 1.f) )
};
static const FIXP_DBL tabEarlyCutRatio[] = {
    FL2FXCONST_DBL( ((1.f/2.f) - 1.f) ),
    FL2FXCONST_DBL( ((1.f/2.f) - 1.f) ),
    FL2FXCONST_DBL( ((1.f/2.f) - 1.f) ),
    FL2FXCONST_DBL( ((1.f/1.f) - 1.f) ),
    FL2FXCONST_DBL( ((1.f/2.f) - 1.f) ),
    FL2FXCONST_DBL( ((1.f/2.f) - 1.f) )
};
static const FIXP_DBL tabCutRatio[]      = {
    FL2FXCONST_DBL( ((1.f/20.f) - 1.f) ),
    FL2FXCONST_DBL( ((1.f/20.f) - 1.f) ),
    FL2FXCONST_DBL( ((1.f/20.f) - 1.f) ),
    FL2FXCONST_DBL( ((1.f/ 2.f) - 1.f) ),
    FL2FXCONST_DBL( ((1.f/20.f) - 1.f) ),
    FL2FXCONST_DBL( ((1.f/20.f) - 1.f) )
};
static const FIXP_DBL tabMaxBoost[] = {
    (FIXP_DBL)( 6<<METADATA_FRACT_BITS),
    (FIXP_DBL)( 6<<METADATA_FRACT_BITS),
    (FIXP_DBL)(12<<METADATA_FRACT_BITS),
    (FIXP_DBL)(12<<METADATA_FRACT_BITS),
    (FIXP_DBL)(15<<METADATA_FRACT_BITS),
    (FIXP_DBL)(15<<METADATA_FRACT_BITS)
};
static const FIXP_DBL tabMaxCut[]   = {
    (FIXP_DBL)(24<<METADATA_FRACT_BITS),
    (FIXP_DBL)(24<<METADATA_FRACT_BITS),
    (FIXP_DBL)(24<<METADATA_FRACT_BITS),
    (FIXP_DBL)(15<<METADATA_FRACT_BITS),
    (FIXP_DBL)(24<<METADATA_FRACT_BITS),
    (FIXP_DBL)(24<<METADATA_FRACT_BITS)
};
static const FIXP_DBL tabFastAttack[] = {
    FL2FXCONST_DBL((10.f/1000.f)/METADATA_INT_SCALE),
    FL2FXCONST_DBL((10.f/1000.f)/METADATA_INT_SCALE),
    FL2FXCONST_DBL((10.f/1000.f)/METADATA_INT_SCALE),
    FL2FXCONST_DBL((10.f/1000.f)/METADATA_INT_SCALE),
    FL2FXCONST_DBL((10.f/1000.f)/METADATA_INT_SCALE),
    FL2FXCONST_DBL( (0.f/1000.f)/METADATA_INT_SCALE)
};
static const FIXP_DBL tabFastDecay[]  = {
    FL2FXCONST_DBL((1000.f/1000.f)/METADATA_INT_SCALE),
    FL2FXCONST_DBL((1000.f/1000.f)/METADATA_INT_SCALE),
    FL2FXCONST_DBL((1000.f/1000.f)/METADATA_INT_SCALE),
    FL2FXCONST_DBL((1000.f/1000.f)/METADATA_INT_SCALE),
    FL2FXCONST_DBL( (200.f/1000.f)/METADATA_INT_SCALE),
    FL2FXCONST_DBL(   (0.f/1000.f)/METADATA_INT_SCALE)
};
static const FIXP_DBL tabSlowAttack[] = {
    FL2FXCONST_DBL((100.f/1000.f)/METADATA_INT_SCALE),
    FL2FXCONST_DBL((100.f/1000.f)/METADATA_INT_SCALE),
    FL2FXCONST_DBL((100.f/1000.f)/METADATA_INT_SCALE),
    FL2FXCONST_DBL((100.f/1000.f)/METADATA_INT_SCALE),
    FL2FXCONST_DBL((100.f/1000.f)/METADATA_INT_SCALE),
    FL2FXCONST_DBL(  (0.f/1000.f)/METADATA_INT_SCALE)
};
static const FIXP_DBL tabSlowDecay[]  = {
    FL2FXCONST_DBL( (3000.f/1000.f)/METADATA_INT_SCALE),
    FL2FXCONST_DBL( (3000.f/1000.f)/METADATA_INT_SCALE),
    FL2FXCONST_DBL((10000.f/1000.f)/METADATA_INT_SCALE),
    FL2FXCONST_DBL( (3000.f/1000.f)/METADATA_INT_SCALE),
    FL2FXCONST_DBL( (1000.f/1000.f)/METADATA_INT_SCALE),
    FL2FXCONST_DBL(    (0.f/1000.f)/METADATA_INT_SCALE)
};

static const INT tabHoldOff[]    = { 10, 10, 10, 10, 10, 0 };

static const FIXP_DBL tabAttackThr[] = {
    (FIXP_DBL)(15<<METADATA_FRACT_BITS),
    (FIXP_DBL)(15<<METADATA_FRACT_BITS),
    (FIXP_DBL)(15<<METADATA_FRACT_BITS),
    (FIXP_DBL)(15<<METADATA_FRACT_BITS),
    (FIXP_DBL)(10<<METADATA_FRACT_BITS),
    (FIXP_DBL)(0<<METADATA_FRACT_BITS)
};
static const FIXP_DBL tabDecayThr[]  = {
    (FIXP_DBL)(20<<METADATA_FRACT_BITS),
    (FIXP_DBL)(20<<METADATA_FRACT_BITS),
    (FIXP_DBL)(20<<METADATA_FRACT_BITS),
    (FIXP_DBL)(20<<METADATA_FRACT_BITS),
    (FIXP_DBL)(10<<METADATA_FRACT_BITS),
    (FIXP_DBL)( 0<<METADATA_FRACT_BITS)
};

/**
 *  Weighting filter coefficients (biquad bandpass).
 */
static const FIXP_DBL b0 = FL2FXCONST_DBL(0.53050662f);                                      /* b1 = 0, b2 = -b0 */
static const FIXP_DBL a1 = FL2FXCONST_DBL(-0.95237983f), a2 = FL2FXCONST_DBL(-0.02248836f);  /* a0 = 1 */


/*------------- function definitions ----------------*/

/**
 * \brief  Calculate scaling factor for denoted processing block.
 *
 * \param blockLength   Length of processing block.
 *
 * \return    shiftFactor
 */
static UINT getShiftFactor(
        const UINT                length
        )
{
    UINT ldN;
    for(ldN=1;(((UINT)1)<<ldN) < length;ldN++);

    return ldN;
}

/**
 * \brief  Sum up fixpoint values with best possible accuracy.
 *
 * \param value1        First input value.
 * \param q1            Scaling factor of first input value.
 * \param pValue2       Pointer to second input value, will be modified on return.
 * \param pQ2           Pointer to second scaling factor, will be modified on return.
 *
 * \return    void
 */
static void fixpAdd(
        const FIXP_DBL                  value1,
        const int                       q1,
        FIXP_DBL *const                 pValue2,
        int *const                      pQ2
        )
{
  const int headroom1 = fNormz(fixp_abs(value1))-1;
  const int headroom2 = fNormz(fixp_abs(*pValue2))-1;
  int resultScale = fixMax(q1-headroom1, (*pQ2)-headroom2);

  if ( (value1!=FL2FXCONST_DBL(0.f)) && (*pValue2!=FL2FXCONST_DBL(0.f)) ) {
    resultScale++;
  }

  *pValue2 = scaleValue(value1, q1-resultScale) + scaleValue(*pValue2, (*pQ2)-resultScale);
  *pQ2 = (*pValue2!=(FIXP_DBL)0) ? resultScale : DFRACT_BITS-1;
}

/**
 * \brief  Function for converting time constant to filter coefficient.
 *
 * \param t             Time constant.
 * \param sampleRate    Sampling rate in Hz.
 * \param blockLength   Length of processing block in samples per channel.
 *
 * \return    result = 1.0 - exp(-1.0/((t) * (f)))
 */
static FIXP_DBL tc2Coeff(
        const FIXP_DBL            t,
        const INT                 sampleRate,
        const INT                 blockLength
        )
{
   FIXP_DBL sampleRateFract;
   FIXP_DBL blockLengthFract;
   FIXP_DBL f, product;
   FIXP_DBL exponent, result;
   INT e_res;

   /* f = sampleRate/blockLength */
   sampleRateFract = (FIXP_DBL)(sampleRate<<(DFRACT_BITS-1-METADATA_LINT_BITS));
   blockLengthFract = (FIXP_DBL)(blockLength<<(DFRACT_BITS-1-METADATA_LINT_BITS));
   f = fDivNorm(sampleRateFract, blockLengthFract, &e_res);
   f = scaleValue(f, e_res-METADATA_INT_BITS); /* convert to METADATA_FRACT */

   /* product = t*f */
   product = fMultNorm(t, f, &e_res);
   product = scaleValue(product, e_res+METADATA_INT_BITS); /* convert to METADATA_FRACT */

   /* exponent = (-1.0/((t) * (f))) */
   exponent = fDivNorm(METADATA_FRACT_SCALE, product, &e_res);
   exponent = scaleValue(exponent, e_res-METADATA_INT_BITS); /* convert to METADATA_FRACT */

   /* exponent * ld(e) */
   exponent = fMult(exponent,FIXP_ILOG2_DIV2)<<1; /* e^(x) = 2^(x*ld(e)) */

   /* exp(-1.0/((t) * (f))) */
   result = f2Pow(-exponent, DFRACT_BITS-1-METADATA_FRACT_BITS, &e_res);

   /* result = 1.0 - exp(-1.0/((t) * (f))) */
   result = FL2FXCONST_DBL(1.0f) - scaleValue(result, e_res);

   return result;
}

INT FDK_DRC_Generator_Open(
        HDRC_COMP                      *phDrcComp
        )
{
    INT err = 0;
    HDRC_COMP hDcComp = NULL;

    if (phDrcComp == NULL) {
      err = -1;
      goto bail;
    }

    /* allocate memory */
    hDcComp = (HDRC_COMP)FDKcalloc(1, sizeof(DRC_COMP));

    if (hDcComp == NULL) {
      err = -1;
      goto bail;
    }

    FDKmemclear(hDcComp, sizeof(DRC_COMP));

    /* Return drc compressor instance */
    *phDrcComp = hDcComp;
    return err;
bail:
    FDK_DRC_Generator_Close(&hDcComp);
    return err;
}

INT FDK_DRC_Generator_Close(
        HDRC_COMP                      *phDrcComp
        )
{
    if (phDrcComp == NULL) {
      return -1;
    }
    if (*phDrcComp != NULL) {
      FDKfree(*phDrcComp);
      *phDrcComp = NULL;
    }
    return 0;
}


INT FDK_DRC_Generator_Initialize(
        HDRC_COMP                       drcComp,
        const DRC_PROFILE               profileLine,
        const DRC_PROFILE               profileRF,
        const INT                       blockLength,
        const UINT                      sampleRate,
        const CHANNEL_MODE              channelMode,
        const CHANNEL_ORDER             channelOrder,
        const UCHAR                     useWeighting
        )
{
    int i;
    CHANNEL_MAPPING channelMapping;

    drcComp->limDecay = FL2FXCONST_DBL( ((0.006f / 256) * blockLength) / METADATA_INT_SCALE );

    /* Save parameters. */
    drcComp->blockLength = blockLength;
    drcComp->sampleRate  = sampleRate;
    drcComp->chanConfig = channelMode;
    drcComp->useWeighting = useWeighting;

    if (FDK_DRC_Generator_setDrcProfile(drcComp, profileLine, profileRF)!=0) { /* expects initialized blockLength and sampleRate */
      return (-1);
    }

    /* Set number of channels and channel offsets. */
    if (FDKaacEnc_InitChannelMapping(channelMode, channelOrder, &channelMapping)!=AAC_ENC_OK) {
      return (-2);
    }

    for (i = 0; i < 9; i++) drcComp->channelIdx[i] = -1;

    switch (channelMode) {
    case MODE_1: /* mono */
        drcComp->channelIdx[C]   = channelMapping.elInfo[0].ChannelIndex[0];
        break;
    case MODE_2: /* stereo */
        drcComp->channelIdx[L]   = channelMapping.elInfo[0].ChannelIndex[0];
        drcComp->channelIdx[R]   = channelMapping.elInfo[0].ChannelIndex[1];
        break;
    case MODE_1_2: /* 3ch */
        drcComp->channelIdx[L]   = channelMapping.elInfo[1].ChannelIndex[0];
        drcComp->channelIdx[R]   = channelMapping.elInfo[1].ChannelIndex[1];
        drcComp->channelIdx[C]   = channelMapping.elInfo[0].ChannelIndex[0];
        break;
    case MODE_1_2_1: /* 4ch */
        drcComp->channelIdx[L]   = channelMapping.elInfo[1].ChannelIndex[0];
        drcComp->channelIdx[R]   = channelMapping.elInfo[1].ChannelIndex[1];
        drcComp->channelIdx[C]   = channelMapping.elInfo[0].ChannelIndex[0];
        drcComp->channelIdx[S]   = channelMapping.elInfo[2].ChannelIndex[0];
        break;
    case MODE_1_2_2: /* 5ch */
        drcComp->channelIdx[L]   = channelMapping.elInfo[1].ChannelIndex[0];
        drcComp->channelIdx[R]   = channelMapping.elInfo[1].ChannelIndex[1];
        drcComp->channelIdx[C]   = channelMapping.elInfo[0].ChannelIndex[0];
        drcComp->channelIdx[LS]  = channelMapping.elInfo[2].ChannelIndex[0];
        drcComp->channelIdx[RS]  = channelMapping.elInfo[2].ChannelIndex[1];
        break;
    case MODE_1_2_2_1:  /* 5.1 ch */
        drcComp->channelIdx[L]   = channelMapping.elInfo[1].ChannelIndex[0];
        drcComp->channelIdx[R]   = channelMapping.elInfo[1].ChannelIndex[1];
        drcComp->channelIdx[C]   = channelMapping.elInfo[0].ChannelIndex[0];
        drcComp->channelIdx[LFE] = channelMapping.elInfo[3].ChannelIndex[0];
        drcComp->channelIdx[LS]  = channelMapping.elInfo[2].ChannelIndex[0];
        drcComp->channelIdx[RS]  = channelMapping.elInfo[2].ChannelIndex[1];
        break;
    case MODE_1_2_2_2_1: /* 7.1 ch */
        drcComp->channelIdx[L]   = channelMapping.elInfo[1].ChannelIndex[0];
        drcComp->channelIdx[R]   = channelMapping.elInfo[1].ChannelIndex[1];
        drcComp->channelIdx[C]   = channelMapping.elInfo[0].ChannelIndex[0];
        drcComp->channelIdx[LFE] = channelMapping.elInfo[4].ChannelIndex[0];
        drcComp->channelIdx[LS]  = channelMapping.elInfo[2].ChannelIndex[0];
        drcComp->channelIdx[RS]  = channelMapping.elInfo[2].ChannelIndex[1];
        drcComp->channelIdx[LS2] = channelMapping.elInfo[3].ChannelIndex[0];
        drcComp->channelIdx[RS2] = channelMapping.elInfo[3].ChannelIndex[1];
        break;
    case MODE_1_1:
    case MODE_1_1_1_1:
    case MODE_1_1_1_1_1_1:
    case MODE_1_1_1_1_1_1_1_1:
    case MODE_1_1_1_1_1_1_1_1_1_1_1_1:
    case MODE_2_2:
    case MODE_2_2_2:
    case MODE_2_2_2_2:
    case MODE_2_2_2_2_2_2:
    default:
        return (-1);
    }

    drcComp->fullChannels = channelMapping.nChannelsEff;
    drcComp->channels     = channelMapping.nChannels;

    /* Init states. */
    drcComp->smoothLevel[0] = drcComp->smoothLevel[1] = (FIXP_DBL)(-135<<METADATA_FRACT_BITS);

    FDKmemclear(drcComp->smoothGain, sizeof(drcComp->smoothGain));
    FDKmemclear(drcComp->holdCnt, sizeof(drcComp->holdCnt));
    FDKmemclear(drcComp->limGain, sizeof(drcComp->limGain));
    FDKmemclear(drcComp->prevPeak, sizeof(drcComp->prevPeak));
    FDKmemclear(drcComp->filter, sizeof(drcComp->filter));

    return (0);
}


INT FDK_DRC_Generator_setDrcProfile(
        HDRC_COMP                       drcComp,
        const DRC_PROFILE               profileLine,
        const DRC_PROFILE               profileRF
        )
{
    int profileIdx, i;

    drcComp->profile[0] = profileLine;
    drcComp->profile[1] = profileRF;

    for (i = 0; i < 2; i++) {
        /* get profile index */
        switch (drcComp->profile[i]) {
            case DRC_NONE:
            case DRC_FILMSTANDARD:  profileIdx = 0; break;
            case DRC_FILMLIGHT:     profileIdx = 1; break;
            case DRC_MUSICSTANDARD: profileIdx = 2; break;
            case DRC_MUSICLIGHT:    profileIdx = 3; break;
            case DRC_SPEECH:        profileIdx = 4; break;
            case DRC_DELAY_TEST:    profileIdx = 5; break;
            default: return (-1);
        }

        /* get parameters for selected profile */
        if (profileIdx >= 0) {
            drcComp->maxBoostThr[i] = tabMaxBoostThr[profileIdx];
            drcComp->boostThr[i]    = tabBoostThr[profileIdx];
            drcComp->earlyCutThr[i] = tabEarlyCutThr[profileIdx];
            drcComp->cutThr[i]      = tabCutThr[profileIdx];
            drcComp->maxCutThr[i]   = tabMaxCutThr[profileIdx];

            drcComp->boostFac[i]    = tabBoostRatio[profileIdx];
            drcComp->earlyCutFac[i] = tabEarlyCutRatio[profileIdx];
            drcComp->cutFac[i]      = tabCutRatio[profileIdx];

            drcComp->maxBoost[i]    = tabMaxBoost[profileIdx];
            drcComp->maxCut[i]      = tabMaxCut[profileIdx];
            drcComp->maxEarlyCut[i] = - fMult((drcComp->cutThr[i] - drcComp->earlyCutThr[i]), drcComp->earlyCutFac[i]); /* no scaling after mult needed, earlyCutFac is in FIXP_DBL */

            drcComp->fastAttack[i]  = tc2Coeff(tabFastAttack[profileIdx], drcComp->sampleRate, drcComp->blockLength);
            drcComp->fastDecay[i]   = tc2Coeff(tabFastDecay[profileIdx], drcComp->sampleRate, drcComp->blockLength);
            drcComp->slowAttack[i]  = tc2Coeff(tabSlowAttack[profileIdx], drcComp->sampleRate, drcComp->blockLength);
            drcComp->slowDecay[i]   = tc2Coeff(tabSlowDecay[profileIdx], drcComp->sampleRate, drcComp->blockLength);
            drcComp->holdOff[i]     = tabHoldOff[profileIdx] * 256 / drcComp->blockLength;

            drcComp->attackThr[i]   = tabAttackThr[profileIdx];
            drcComp->decayThr[i]    = tabDecayThr[profileIdx];
        }

        drcComp->smoothGain[i] = FL2FXCONST_DBL(0.f);
    }
    return (0);
}


INT FDK_DRC_Generator_Calc(
        HDRC_COMP                       drcComp,
        const INT_PCM * const           inSamples,
        const INT                       dialnorm,
        const INT                       drc_TargetRefLevel,
        const INT                       comp_TargetRefLevel,
        FIXP_DBL                        clev,
        FIXP_DBL                        slev,
        INT * const                     pDynrng,
        INT * const                     pCompr
        )
{
    int i, c;
    FIXP_DBL peak[2];


    /**************************************************************************
    * compressor
    **************************************************************************/
      if ((drcComp->profile[0] != DRC_NONE) || (drcComp->profile[1] != DRC_NONE)) {
        /* Calc loudness level */
        FIXP_DBL level_b = FL2FXCONST_DBL(0.f);
        int      level_e = DFRACT_BITS-1;

        /* Increase energy time resolution with shorter processing blocks. 32 is an empiric value. */
        const int granuleLength = fixMin(32, drcComp->blockLength);

        if (drcComp->useWeighting) {
            FIXP_DBL x1, x2, y, y1, y2;
            /* sum of filter coefficients about 2.5 -> squared value is 6.25
               WEIGHTING_FILTER_SHIFT is 2 -> scaling about 16, therefore reduce granuleShift by 1.
             */
            const int granuleShift = getShiftFactor(granuleLength)-1;

            for (c = 0; c < (int)drcComp->channels; c++) {
                const INT_PCM* pSamples = &inSamples[c];

                if (c == drcComp->channelIdx[LFE]) {
                  continue;  /* skip LFE */
                }

                /* get filter states */
                x1 = drcComp->filter[c].x1;
                x2 = drcComp->filter[c].x2;
                y1 = drcComp->filter[c].y1;
                y2 = drcComp->filter[c].y2;

                i = 0;

                do {

                  int offset = i;
                  FIXP_DBL accu = FL2FXCONST_DBL(0.f);

                  for (i=offset; i < fixMin(offset+granuleLength,drcComp->blockLength); i++) {
                    /* apply weighting filter */
                    FIXP_DBL x = FX_PCM2FX_DBL((FIXP_PCM)pSamples[i*drcComp->channels]) >> WEIGHTING_FILTER_SHIFT;

                    /* y = b0 * (x - x2) - a1 * y1 - a2 * y2; */
                    y = fMult(b0,x-x2) - fMult(a1,y1) - fMult(a2,y2);

                    x2 = x1;
                    x1 = x;
                    y2 = y1;
                    y1 = y;

                    accu += fPow2Div2(y)>>(granuleShift-1);     /* partial energy */
                  } /* i */

                  fixpAdd(accu, granuleShift+2*WEIGHTING_FILTER_SHIFT, &level_b, &level_e); /* sup up partial energies */

                } while ( i < drcComp->blockLength );


                /* save filter states */
                drcComp->filter[c].x1 = x1;
                drcComp->filter[c].x2 = x2;
                drcComp->filter[c].y1 = y1;
                drcComp->filter[c].y2 = y2;
            } /* c */
        } /* weighting */
        else {
            const int granuleShift = getShiftFactor(granuleLength);

            for (c = 0; c < (int)drcComp->channels; c++) {
                const INT_PCM* pSamples = &inSamples[c];

                if ((int)c == drcComp->channelIdx[LFE]) {
                  continue;  /* skip LFE */
                }

                i = 0;

                do {
                  int offset = i;
                  FIXP_DBL accu = FL2FXCONST_DBL(0.f);

                  for (i=offset; i < fixMin(offset+granuleLength,drcComp->blockLength); i++) {
                    /* partial energy */
                    accu += fPow2Div2((FIXP_PCM)pSamples[i*drcComp->channels])>>(granuleShift-1);
                  } /* i */

                  fixpAdd(accu, granuleShift, &level_b, &level_e); /* sup up partial energies */

                } while ( i < drcComp->blockLength );
            }
        } /* weighting */

        /*
         * Convert to dBFS, apply dialnorm
         */
        /* level scaling */

        /* descaled level in ld64 representation */
        FIXP_DBL ldLevel = CalcLdData(level_b) + (FIXP_DBL)((level_e-12)<<(DFRACT_BITS-1-LD_DATA_SHIFT)) - CalcLdData((FIXP_DBL)(drcComp->blockLength<<(DFRACT_BITS-1-12)));

        /* if (level < 1e-10) level = 1e-10f; */
        ldLevel = FDKmax(ldLevel, FL2FXCONST_DBL(-0.51905126482615036685473741085772f));

        /* level = 10 * log(level)/log(10) + 3;
         *       = 10*log(2)/log(10) * ld(level) + 3;
         *       = 10 * 0.30102999566398119521373889472449 * ld(level) + 3
         *       = 10 * (0.30102999566398119521373889472449 * ld(level) + 0.3)
         *       = 10 * (0.30102999566398119521373889472449 * ld64(level) + 0.3/64) * 64
         *
         *    additional scaling with METADATA_FRACT_BITS:
         *       = 10 * (0.30102999566398119521373889472449 * ld64(level) + 0.3/64) * 64 * 2^(METADATA_FRACT_BITS)
         *       = 10 * (0.30102999566398119521373889472449 * ld64(level) + 0.3/64) * 2^(METADATA_FRACT_BITS+LD_DATA_SHIFT)
         *       = 10*2^(METADATA_FRACT_BITS+LD_DATA_SHIFT) * ( 0.30102999566398119521373889472449 * ld64(level) + 0.3/64 )
         * */
        FIXP_DBL level = fMult((FIXP_DBL)(10<<(METADATA_FRACT_BITS+LD_DATA_SHIFT)), fMult( FL2FXCONST_DBL(0.30102999566398119521373889472449f), ldLevel) + (FIXP_DBL)(FL2FXCONST_DBL(0.3f)>>LD_DATA_SHIFT) );

        /* level -= dialnorm + 31 */   /* this is fixed to Dolby-ReferenceLevel as compressor profiles are defined relative to this */
        level -= ((FIXP_DBL)(dialnorm<<(METADATA_FRACT_BITS-16))  + (FIXP_DBL)(31<<METADATA_FRACT_BITS));

        for (i = 0; i < 2; i++) {
            if (drcComp->profile[i] == DRC_NONE) {
                /* no compression */
                drcComp->smoothGain[i] = FL2FXCONST_DBL(0.f);
            }
            else {
                FIXP_DBL gain, alpha, lvl2smthlvl;

                /* calc static gain */
                if (level <= drcComp->maxBoostThr[i]) {
                    /* max boost */
                    gain = drcComp->maxBoost[i];
                }
                else if (level < drcComp->boostThr[i]) {
                    /* boost range */
                    gain = fMult((level - drcComp->boostThr[i]),drcComp->boostFac[i]);
                }
                else if (level <= drcComp->earlyCutThr[i]) {
                    /* null band */
                    gain = FL2FXCONST_DBL(0.f);
                }
                else if (level <= drcComp->cutThr[i]) {
                    /* early cut range */
                    gain = fMult((level - drcComp->earlyCutThr[i]), drcComp->earlyCutFac[i]);
                }
                else if (level < drcComp->maxCutThr[i]) {
                    /* cut range */
                    gain = fMult((level - drcComp->cutThr[i]), drcComp->cutFac[i]) - drcComp->maxEarlyCut[i];
                }
                else {
                    /* max cut */
                    gain = -drcComp->maxCut[i];
                }

                /* choose time constant */
                lvl2smthlvl = level - drcComp->smoothLevel[i];
                if (gain < drcComp->smoothGain[i]) {
                    /* attack */
                    if (lvl2smthlvl > drcComp->attackThr[i]) {
                        /* fast attack */
                        alpha = drcComp->fastAttack[i];
                    }
                    else {
                        /* slow attack */
                        alpha = drcComp->slowAttack[i];
                    }
                }
                else {
                    /* release */
                    if (lvl2smthlvl < -drcComp->decayThr[i]) {
                        /* fast release */
                        alpha = drcComp->fastDecay[i];
                    }
                    else {
                        /* slow release */
                        alpha = drcComp->slowDecay[i];
                    }
                }

                /* smooth gain & level */
                if ((gain < drcComp->smoothGain[i]) || (drcComp->holdCnt[i] == 0)) { /* hold gain unless we have an attack or hold period is over */
                    FIXP_DBL accu;

                    /* drcComp->smoothLevel[i] = (1-alpha) * drcComp->smoothLevel[i] + alpha * level; */
                    accu =  fMult((FL2FXCONST_DBL(1.f)-alpha), drcComp->smoothLevel[i]);
                    accu += fMult(alpha,level);
                    drcComp->smoothLevel[i] = accu;

                    /* drcComp->smoothGain[i]  = (1-alpha) * drcComp->smoothGain[i] + alpha * gain; */
                    accu =  fMult((FL2FXCONST_DBL(1.f)-alpha), drcComp->smoothGain[i]);
                    accu += fMult(alpha,gain);
                    drcComp->smoothGain[i] = accu;
                }

                /* hold counter */
                if (drcComp->holdCnt[i]) {
                  drcComp->holdCnt[i]--;
                }
                if (gain < drcComp->smoothGain[i]) {
                  drcComp->holdCnt[i] = drcComp->holdOff[i];
                }
            } /* profile != DRC_NONE */
        } /* for i=1..2 */
      } else {
        /* no compression */
        drcComp->smoothGain[0] = FL2FXCONST_DBL(0.f);
        drcComp->smoothGain[1] = FL2FXCONST_DBL(0.f);
      }

    /**************************************************************************
    * limiter
    **************************************************************************/

    /* find peak level */
    peak[0] = peak[1] = FL2FXCONST_DBL(0.f);
    for (i = 0; i < drcComp->blockLength; i++) {
        FIXP_DBL tmp;
        const INT_PCM* pSamples = &inSamples[i*drcComp->channels];
        INT_PCM maxSample = 0;

        /* single channels */
        for (c = 0; c < (int)drcComp->channels; c++) {
            maxSample = FDKmax(maxSample, fAbs(pSamples[c]));
        }
        peak[0] = fixMax(peak[0], FX_PCM2FX_DBL(maxSample)>>DOWNMIX_SHIFT);

        /* Lt/Rt downmix */
        if (drcComp->fullChannels > 2) {
            /* Lt */
            tmp = FL2FXCONST_DBL(0.f);

            if (drcComp->channelIdx[LS] >= 0) tmp -= fMultDiv2(FL2FXCONST_DBL(0.707f), (FIXP_PCM)pSamples[drcComp->channelIdx[LS]])>>(DOWNMIX_SHIFT-1);          /* Ls */
            if (drcComp->channelIdx[LS2] >= 0) tmp -= fMultDiv2(FL2FXCONST_DBL(0.707f), (FIXP_PCM)pSamples[drcComp->channelIdx[LS2]])>>(DOWNMIX_SHIFT-1);        /* Ls2 */
            if (drcComp->channelIdx[RS] >= 0) tmp -= fMultDiv2(FL2FXCONST_DBL(0.707f), (FIXP_PCM)pSamples[drcComp->channelIdx[RS]])>>(DOWNMIX_SHIFT-1);          /* Rs */
            if (drcComp->channelIdx[RS2] >= 0) tmp -= fMultDiv2(FL2FXCONST_DBL(0.707f), (FIXP_PCM)pSamples[drcComp->channelIdx[RS2]])>>(DOWNMIX_SHIFT-1);        /* Rs2 */
            if ((drcComp->channelIdx[LS] >= 0) && (drcComp->channelIdx[LS2] >= 0)) tmp = fMult(FL2FXCONST_DBL(0.707f), tmp);                                     /* 7.1ch */
            if (drcComp->channelIdx[S] >= 0) tmp -= fMultDiv2(FL2FXCONST_DBL(0.707f), (FIXP_PCM)pSamples[drcComp->channelIdx[S]])>>(DOWNMIX_SHIFT-1);            /* S */
            if (drcComp->channelIdx[C] >= 0) tmp += fMultDiv2(FL2FXCONST_DBL(0.707f), (FIXP_PCM)pSamples[drcComp->channelIdx[C]])>>(DOWNMIX_SHIFT-1);            /* C */
            tmp += (FX_PCM2FX_DBL((FIXP_PCM)pSamples[drcComp->channelIdx[L]])>>DOWNMIX_SHIFT);                                                                   /* L */

            peak[0] = fixMax(peak[0], fixp_abs(tmp));

            /* Rt */
            tmp = FL2FXCONST_DBL(0.f);
            if (drcComp->channelIdx[LS] >= 0) tmp += fMultDiv2(FL2FXCONST_DBL(0.707f), (FIXP_PCM)pSamples[drcComp->channelIdx[LS]])>>(DOWNMIX_SHIFT-1);          /* Ls */
            if (drcComp->channelIdx[LS2] >= 0) tmp += fMultDiv2(FL2FXCONST_DBL(0.707f), (FIXP_PCM)pSamples[drcComp->channelIdx[LS2]])>>(DOWNMIX_SHIFT-1);        /* Ls2 */
            if (drcComp->channelIdx[RS] >= 0) tmp += fMultDiv2(FL2FXCONST_DBL(0.707f), (FIXP_PCM)pSamples[drcComp->channelIdx[RS]])>>(DOWNMIX_SHIFT-1);          /* Rs */
            if (drcComp->channelIdx[RS2] >= 0) tmp += fMultDiv2(FL2FXCONST_DBL(0.707f), (FIXP_PCM)pSamples[drcComp->channelIdx[RS2]])>>(DOWNMIX_SHIFT-1);        /* Rs2 */
            if ((drcComp->channelIdx[RS] >= 0) && (drcComp->channelIdx[RS2] >= 0)) tmp = fMult(FL2FXCONST_DBL(0.707f), tmp);                                     /* 7.1ch */
            if (drcComp->channelIdx[S] >= 0) tmp += fMultDiv2(FL2FXCONST_DBL(0.707f), (FIXP_PCM)pSamples[drcComp->channelIdx[S]])>>(DOWNMIX_SHIFT-1);            /* S */
            if (drcComp->channelIdx[C] >= 0) tmp += fMultDiv2(FL2FXCONST_DBL(0.707f), (FIXP_PCM)pSamples[drcComp->channelIdx[C]])>>(DOWNMIX_SHIFT-1);            /* C */
            tmp += (FX_PCM2FX_DBL((FIXP_PCM)pSamples[drcComp->channelIdx[R]])>>DOWNMIX_SHIFT);                                                                   /* R */

            peak[0] = fixMax(peak[0], fixp_abs(tmp));
        }

        /* Lo/Ro downmix */
        if (drcComp->fullChannels > 2) {
            /* Lo */
            tmp = FL2FXCONST_DBL(0.f);
            if (drcComp->channelIdx[LS] >= 0) tmp += fMultDiv2(slev, (FIXP_PCM)pSamples[drcComp->channelIdx[LS]])>>(DOWNMIX_SHIFT-1);                            /* Ls */
            if (drcComp->channelIdx[LS2] >= 0) tmp += fMultDiv2(slev, (FIXP_PCM)pSamples[drcComp->channelIdx[LS2]])>>(DOWNMIX_SHIFT-1);                          /* Ls2 */
            if ((drcComp->channelIdx[LS] >= 0) && (drcComp->channelIdx[LS2] >= 0)) tmp = fMult(FL2FXCONST_DBL(0.707f), tmp);                                     /* 7.1ch */
            if (drcComp->channelIdx[S] >= 0) tmp += fMultDiv2(slev, fMult(FL2FXCONST_DBL(0.7f), (FIXP_PCM)pSamples[drcComp->channelIdx[S]]))>>(DOWNMIX_SHIFT-1); /* S */
            if (drcComp->channelIdx[C] >= 0) tmp += fMultDiv2(clev, (FIXP_PCM)pSamples[drcComp->channelIdx[C]])>>(DOWNMIX_SHIFT-1);                              /* C */
            tmp += (FX_PCM2FX_DBL((FIXP_PCM)pSamples[drcComp->channelIdx[L]])>>DOWNMIX_SHIFT);                                                                   /* L */

            peak[0] = fixMax(peak[0], fixp_abs(tmp));

            /* Ro */
            tmp = FL2FXCONST_DBL(0.f);
            if (drcComp->channelIdx[RS] >= 0) tmp += fMultDiv2(slev, (FIXP_PCM)pSamples[drcComp->channelIdx[RS]])>>(DOWNMIX_SHIFT-1);                            /* Rs */
            if (drcComp->channelIdx[RS2] >= 0) tmp += fMultDiv2(slev, (FIXP_PCM)pSamples[drcComp->channelIdx[RS2]])>>(DOWNMIX_SHIFT-1);                          /* Rs2 */
            if ((drcComp->channelIdx[RS] >= 0) && (drcComp->channelIdx[RS2] >= 0)) tmp = fMult(FL2FXCONST_DBL(0.707f), tmp);                                     /* 7.1ch */
            if (drcComp->channelIdx[S] >= 0) tmp += fMultDiv2(slev, fMult(FL2FXCONST_DBL(0.7f), (FIXP_PCM)pSamples[drcComp->channelIdx[S]]))>>(DOWNMIX_SHIFT-1); /* S */
            if (drcComp->channelIdx[C] >= 0) tmp += fMultDiv2(clev, (FIXP_PCM)pSamples[drcComp->channelIdx[C]])>>(DOWNMIX_SHIFT-1);                              /* C */
            tmp += (FX_PCM2FX_DBL((FIXP_PCM)pSamples[drcComp->channelIdx[R]])>>DOWNMIX_SHIFT);                                                                   /* R */

            peak[0] = fixMax(peak[0], fixp_abs(tmp));
        }

        peak[1] = fixMax(peak[0], peak[1]);

        /* Mono Downmix - for comp_val only */
        if (drcComp->fullChannels > 1) {
            tmp = FL2FXCONST_DBL(0.f);
            if (drcComp->channelIdx[LS] >= 0) tmp += fMultDiv2(slev, (FIXP_PCM)pSamples[drcComp->channelIdx[LS]])>>(DOWNMIX_SHIFT-1);                            /* Ls */
            if (drcComp->channelIdx[LS2] >= 0) tmp += fMultDiv2(slev, (FIXP_PCM)pSamples[drcComp->channelIdx[LS2]])>>(DOWNMIX_SHIFT-1);                          /* Ls2 */
            if (drcComp->channelIdx[RS] >= 0) tmp += fMultDiv2(slev, (FIXP_PCM)pSamples[drcComp->channelIdx[RS]])>>(DOWNMIX_SHIFT-1);                            /* Rs */
            if (drcComp->channelIdx[RS2] >= 0) tmp += fMultDiv2(slev, (FIXP_PCM)pSamples[drcComp->channelIdx[RS2]])>>(DOWNMIX_SHIFT-1);                          /* Rs2 */
            if ((drcComp->channelIdx[LS] >= 0) && (drcComp->channelIdx[LS2] >= 0)) tmp = fMult(FL2FXCONST_DBL(0.707f), tmp);                                     /* 7.1ch */
            /*if ((drcComp->channelIdx[RS] >= 0) && (drcComp->channelIdx[RS2] >= 0)) tmp *=0.707f;*/                                                             /* 7.1ch */
            if (drcComp->channelIdx[S] >= 0) tmp += fMultDiv2(slev, fMult(FL2FXCONST_DBL(0.7f), (FIXP_PCM)pSamples[drcComp->channelIdx[S]]))>>(DOWNMIX_SHIFT-1); /* S */
            if (drcComp->channelIdx[C] >= 0) tmp += fMultDiv2(clev, (FIXP_PCM)pSamples[drcComp->channelIdx[C]])>>(DOWNMIX_SHIFT-1);                              /* C */
            tmp += (FX_PCM2FX_DBL((FIXP_PCM)pSamples[drcComp->channelIdx[L]])>>DOWNMIX_SHIFT);                                                                   /* L */
            tmp += (FX_PCM2FX_DBL((FIXP_PCM)pSamples[drcComp->channelIdx[R]])>>DOWNMIX_SHIFT);                                                                   /* R */

            peak[1] = fixMax(peak[1], fixp_abs(tmp));
        }
    }

    for (i=0; i<2; i++) {
      FIXP_DBL tmp = drcComp->prevPeak[i];
      drcComp->prevPeak[i] = peak[i];
      peak[i] = fixMax(peak[i], tmp);

      /*
       * Convert to dBFS, apply dialnorm
       */
      /* descaled peak in ld64 representation */
      FIXP_DBL ld_peak = CalcLdData(peak[i]) + (FIXP_DBL)((LONG)DOWNMIX_SHIFT<<(DFRACT_BITS-1-LD_DATA_SHIFT));

      /* if (peak < 1e-6) level = 1e-6f; */
      ld_peak = FDKmax(ld_peak, FL2FXCONST_DBL(-0.31143075889569022011284244651463f));

      /* peak[i] = 20 * log(peak[i])/log(10) + 0.2f + (drcComp->smoothGain[i]*2^METADATA_FRACT_BITS)
       * peak[i] = 20 * log(2)/log(10) * ld(peak[i]) + 0.2f + (drcComp->smoothGain[i]*2^METADATA_FRACT_BITS)
       * peak[i] = 10 * 2*0.30102999566398119521373889472449 * ld(peak[i]) + 0.2f + (drcComp->smoothGain[i]*2^METADATA_FRACT_BITS)
       *
       *    additional scaling with METADATA_FRACT_BITS:
       * peak[i] = (10 * 2*0.30102999566398119521373889472449 * ld64(peak[i]) * 64 + 0.2f + (drcComp->smoothGain[i]*2^METADATA_FRACT_BITS))*2^(-METADATA_FRACT_BITS)
       * peak[i] = 10*2^(METADATA_FRACT_BITS+LD_DATA_SHIFT) * 2*0.30102999566398119521373889472449 * ld64(peak[i])
       *         + 0.2f*2^(-METADATA_FRACT_BITS) + drcComp->smoothGain[i]
       */
      peak[i] = fMult((FIXP_DBL)(10<<(METADATA_FRACT_BITS+LD_DATA_SHIFT)), fMult( FL2FX_DBL(2*0.30102999566398119521373889472449f), ld_peak));
      peak[i] += (FL2FX_DBL(0.2f)>>METADATA_INT_BITS);           /* add a little bit headroom */
      peak[i] +=  drcComp->smoothGain[i];
    }

    /* peak -= dialnorm + 31; */  /* this is Dolby style only */
    peak[0] -= (FIXP_DBL)((dialnorm-drc_TargetRefLevel)<<(METADATA_FRACT_BITS-16)); /* peak[0] -= dialnorm - drc_TargetRefLevel */

    /* peak += 11; */   /* this is Dolby style only */      /* RF mode output is 11dB higher */
    /*peak += comp_TargetRefLevel - drc_TargetRefLevel;*/
    peak[1] -= (FIXP_DBL)((dialnorm-comp_TargetRefLevel)<<(METADATA_FRACT_BITS-16)); /* peak[1] -= dialnorm - comp_TargetRefLevel */

    /* limiter gain */
    drcComp->limGain[0] += drcComp->limDecay;               /* linear limiter release */
    drcComp->limGain[0] = fixMin(drcComp->limGain[0], -peak[0]);

    drcComp->limGain[1] += 2*drcComp->limDecay;             /* linear limiter release */
    drcComp->limGain[1] = fixMin(drcComp->limGain[1], -peak[1]);

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

    /* apply limiting, return DRC gains*/
    {
        FIXP_DBL tmp;

        tmp = drcComp->smoothGain[0];
        if (drcComp->limGain[0] < FL2FXCONST_DBL(0.f)) {
          tmp += drcComp->limGain[0];
        }
        *pDynrng = (LONG) scaleValue(tmp, -(METADATA_FRACT_BITS-16));

        tmp = drcComp->smoothGain[1];
        if (drcComp->limGain[1] < FL2FXCONST_DBL(0.f)) {
          tmp += drcComp->limGain[1];
        }
        *pCompr  = (LONG) scaleValue(tmp, -(METADATA_FRACT_BITS-16));
    }

    return 0;
}


DRC_PROFILE FDK_DRC_Generator_getDrcProfile(const HDRC_COMP drcComp)
{
    return drcComp->profile[0];
}

DRC_PROFILE FDK_DRC_Generator_getCompProfile(const HDRC_COMP drcComp)
{
    return drcComp->profile[1];
}