path: root/libAACenc/src/psy_configuration.cpp

/******************************** MPEG Audio Encoder **************************

                     (C) Copyright Fraunhofer IIS (1999)
                               All Rights Reserved

    Please be advised that this software and/or program delivery is
    Confidential Information of Fraunhofer and subject to and covered by the

    Fraunhofer IIS Software Evaluation Agreement
    between Google Inc. and  Fraunhofer
    effective and in full force since March 1, 2012.

    You may use this software and/or program only under the terms and
    conditions described in the above mentioned Fraunhofer IIS Software
    Evaluation Agreement. Any other and/or further use requires a separate agreement.


   This software and/or program is protected by copyright law and international
   treaties. Any reproduction or distribution of this software and/or program,
   or any portion of it, may result in severe civil and criminal penalties, and
   will be prosecuted to the maximum extent possible under law.

   $Id$
   Initial author:       M.Werner
   contents/description: Psychoaccoustic configuration

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

#include "psy_configuration.h"
#include "adj_thr.h"
#include "aacEnc_rom.h"

#include "genericStds.h"

#include "FDK_trigFcts.h"

typedef struct{
    LONG  sampleRate;
    const SFB_PARAM_LONG  *paramLong;
    const SFB_PARAM_SHORT *paramShort;
}SFB_INFO_TAB;


static const SFB_INFO_TAB sfbInfoTab[] = {
    {8000,  &p_FDKaacEnc_8000_long_1024,  &p_FDKaacEnc_8000_short_128},
    {11025, &p_FDKaacEnc_11025_long_1024, &p_FDKaacEnc_11025_short_128},
    {12000, &p_FDKaacEnc_12000_long_1024, &p_FDKaacEnc_12000_short_128},
    {16000, &p_FDKaacEnc_16000_long_1024, &p_FDKaacEnc_16000_short_128},
    {22050, &p_FDKaacEnc_22050_long_1024, &p_FDKaacEnc_22050_short_128},
    {24000, &p_FDKaacEnc_24000_long_1024, &p_FDKaacEnc_24000_short_128},
    {32000, &p_FDKaacEnc_32000_long_1024, &p_FDKaacEnc_32000_short_128},
    {44100, &p_FDKaacEnc_44100_long_1024, &p_FDKaacEnc_44100_short_128},
    {48000, &p_FDKaacEnc_48000_long_1024, &p_FDKaacEnc_48000_short_128},
    {64000, &p_FDKaacEnc_64000_long_1024, &p_FDKaacEnc_64000_short_128},
    {88200, &p_FDKaacEnc_88200_long_1024, &p_FDKaacEnc_88200_short_128},
    {96000, &p_FDKaacEnc_96000_long_1024, &p_FDKaacEnc_96000_short_128}

};

/* 22050 and 24000 Hz */
static const SFB_PARAM_LONG p_22050_long_512 = {
    31,
    {  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,
       4,  8,  8,  8, 12, 12, 12, 16, 20, 24,
      28, 32, 32, 32, 32, 32, 32, 32, 32, 32,
      32}
};

/* 32000 Hz */
static const SFB_PARAM_LONG p_32000_long_512 = {
    37,
    {  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,
       4,  4,  4,  4,  8,  8,  8,  8,  8, 12,
      12, 12, 12, 16, 16, 16, 20, 24, 24, 28,
      32, 32, 32, 32, 32, 32, 32}
};

/* 44100 Hz */
static const SFB_PARAM_LONG p_44100_long_512 = {
    36,
    {4,  4,  4,  4,  4,  4,  4,  4,  4,  4,
     4,  4,  4,  4,  4,  8,  8,  8,  8,  8,
    12, 12, 12, 12, 16, 20, 24, 28, 32, 32,
    32, 32, 32, 32, 32, 52}
};

static const SFB_INFO_TAB sfbInfoTabLD512[] = {
    { 8000, &p_22050_long_512, NULL},
    {11025, &p_22050_long_512, NULL},
    {12000, &p_22050_long_512, NULL},
    {16000, &p_22050_long_512, NULL},
    {22050, &p_22050_long_512, NULL},
    {24000, &p_22050_long_512, NULL},
    {32000, &p_32000_long_512, NULL},
    {44100, &p_44100_long_512, NULL},
    {48000, &p_44100_long_512, NULL},
    {64000, &p_44100_long_512, NULL},
    {88200, &p_44100_long_512, NULL},
    {96000, &p_44100_long_512, NULL},

};


/* 22050 and 24000 Hz */
static const SFB_PARAM_LONG p_22050_long_480 = {
    30,
    { 4,  4,  4,  4,  4,  4,  4,  4,  4,  4,
      4,  8,  8,  8, 12, 12, 12, 16, 20, 24,
     28, 32, 32, 32, 32, 32, 32, 32, 32, 32}
};

/* 32000 Hz */
static const SFB_PARAM_LONG p_32000_long_480 = {
    37,
    { 4,  4,  4,  4,  4,  4,  4,  4,  4,  4,
      4,  4,  4,  4,  4,  4,  8,  8,  8,  8,
      8,  8, 12, 12, 12, 16, 16, 20, 24, 32,
     32, 32, 32, 32, 32, 32, 32}
};

/* 44100 Hz */
static const SFB_PARAM_LONG p_44100_long_480 = {
    35,
    { 4,  4,  4,  4,  4,  4,  4,  4,  4,  4,
      4,  4,  4,  4,  8,  8,  8,  8,  8, 12,
     12, 12, 12, 12, 16, 16, 24, 28, 32, 32,
     32, 32, 32, 32, 48}
};

static const SFB_INFO_TAB sfbInfoTabLD480[] = {
    { 8000, &p_22050_long_480, NULL},
    {11025, &p_22050_long_480, NULL},
    {12000, &p_22050_long_480, NULL},
    {16000, &p_22050_long_480, NULL},
    {22050, &p_22050_long_480, NULL},
    {24000, &p_22050_long_480, NULL},
    {32000, &p_32000_long_480, NULL},
    {44100, &p_44100_long_480, NULL},
    {48000, &p_44100_long_480, NULL},
    {64000, &p_44100_long_480, NULL},
    {88200, &p_44100_long_480, NULL},
    {96000, &p_44100_long_480, NULL},

};

/* Fixed point precision definitions */
#define Q_BARCVAL        (25)

static AAC_ENCODER_ERROR FDKaacEnc_initSfbTable(LONG sampleRate, INT blockType, INT granuleLength, INT *sfbOffset, INT *sfbCnt)
{
  INT  i, specStartOffset = 0;
  const UCHAR* sfbWidth = NULL;
  const SFB_INFO_TAB *sfbInfo = NULL;
  int size;

  /*
    select table
  */
  switch(granuleLength) {
    case 1024:
    case  960:
      sfbInfo = sfbInfoTab;
      size = (INT)(sizeof(sfbInfoTab)/sizeof(SFB_INFO_TAB));
      break;
    case 512:
      sfbInfo = sfbInfoTabLD512;
      size = sizeof(sfbInfoTabLD512);
      break;
    case 480:
      sfbInfo = sfbInfoTabLD480;
      size = sizeof(sfbInfoTabLD480);
      break;
    default:
      return AAC_ENC_INVALID_FRAME_LENGTH;
  }

  for(i = 0; i < size; i++){
    if(sfbInfo[i].sampleRate == sampleRate){
      switch(blockType){
      case LONG_WINDOW:
      case START_WINDOW:
      case STOP_WINDOW:
        sfbWidth = sfbInfo[i].paramLong->sfbWidth;
        *sfbCnt  = sfbInfo[i].paramLong->sfbCnt;
        break;
      case SHORT_WINDOW:
        sfbWidth = sfbInfo[i].paramShort->sfbWidth;
        *sfbCnt  = sfbInfo[i].paramShort->sfbCnt;
        granuleLength /= TRANS_FAC;
        break;
      }
      break;
    }
  }
  if (i == size) {
    return AAC_ENC_UNSUPPORTED_SAMPLINGRATE;
  }

  /*
    calc sfb offsets
  */
  for(i = 0; i < *sfbCnt; i++){
      sfbOffset[i] = specStartOffset;
      specStartOffset += sfbWidth[i];
      if (specStartOffset >= granuleLength) {
          i++;
          break;
      }
  }
  *sfbCnt = fixMin(i,*sfbCnt);
  sfbOffset[*sfbCnt] = fixMin(specStartOffset,granuleLength);

  return AAC_ENC_OK;
}


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

    functionname: FDKaacEnc_BarcLineValue
    description:  Calculates barc value for one frequency line
    returns:      barc value of line
    input:        number of lines in transform, index of line to check, Fs
    output:

*****************************************************************************/
static FIXP_DBL FDKaacEnc_BarcLineValue(INT noOfLines, INT fftLine, LONG samplingFreq)
{

    FIXP_DBL FOURBY3EM4     = (FIXP_DBL)0x45e7b273; /* 4.0/3 * 0.0001 in q43 */
    FIXP_DBL PZZZ76         = (FIXP_DBL)0x639d5e4a; /* 0.00076 in q41 */
    FIXP_DBL ONE3P3         = (FIXP_DBL)0x35333333; /* 13.3 in q26 */
    FIXP_DBL THREEP5        = (FIXP_DBL)0x1c000000; /* 3.5 in q27 */
    FIXP_DBL INV480         = (FIXP_DBL)0x44444444; // 1/480 in q39

    FIXP_DBL center_freq, x1, x2;
    FIXP_DBL bvalFFTLine, atan1, atan2;

    /* Theoritical maximum of center_freq (samp_freq*0.5) is 96khz * 0.5 = 48000        */
    /* Theoritical maximum of x1 is 1.3333333e-4f * center_freq = 6.4, can keep in q28  */
    /* Theoritical maximum of x2 is 0.00076f * center_freq = 36.48, can keep in q25     */

    center_freq = fftLine * samplingFreq;       /* q11 or q8 */

    switch (noOfLines) {
      case 1024:
        center_freq = center_freq << 2; /* q13 */
        break;
      case 128:
        center_freq = center_freq << 5; /* q13 */
        break;
      case 512:
        center_freq = (fftLine * samplingFreq) << 3;   // q13
        break;
      case 480:
        center_freq = fMult(center_freq, INV480) << 4; // q13
        break;
      default:
        center_freq = (FIXP_DBL)0;
    }

    x1 = fMult(center_freq, FOURBY3EM4);        /* q13 * q43 - (DFRACT_BITS-1) = q25 */
    x2 = fMult(center_freq, PZZZ76) << 2;       /* q13 * q41 - (DFRACT_BITS-1) + 2 = q25 */

    atan1 = fixp_atan(x1);
    atan2 = fixp_atan(x2);

    /* q25 (q26 * q30 - (DFRACT_BITS-1)) + q25 (q27 * q30 * q30) */
    bvalFFTLine = fMult(ONE3P3, atan2) + fMult(THREEP5, fMult(atan1, atan1));
    return(bvalFFTLine);

}

/*
   do not consider energies below a certain input signal level,
   i.e. of -96dB or 1 bit at 16 bit PCM resolution,
   might need to be configurable to e.g. 24 bit PCM Input or a lower
   resolution for low bit rates
*/
static void FDKaacEnc_InitMinPCMResolution(int   numPb,
                                 int   *pbOffset,
                                 FIXP_DBL *sfbPCMquantThreshold)
{
  /* PCM_QUANT_NOISE = FDKpow(10.0f, - 20.f / 10.0f) * ABS_LOW * NORM_PCM_ENERGY * FDKpow(2,PCM_QUANT_THR_SCALE) */
  #define PCM_QUANT_NOISE  ((FIXP_DBL)0x00547062)

  for( int i = 0; i < numPb; i++ ) {
    sfbPCMquantThreshold[i] = (pbOffset[i+1] - pbOffset[i]) * PCM_QUANT_NOISE;
  }
}

static FIXP_DBL getMaskFactor(
        const FIXP_DBL dbVal_fix,
        const INT      dbVal_e,
        const FIXP_DBL ten_fix,
        const INT      ten_e
        )
{
    INT q_msk;
    FIXP_DBL mask_factor;

    mask_factor = fPow(ten_fix, DFRACT_BITS-1-ten_e, -dbVal_fix, DFRACT_BITS-1-dbVal_e, &q_msk);
    q_msk = fixMin(DFRACT_BITS-1,fixMax(-(DFRACT_BITS-1),q_msk));

    if ( (q_msk>0) && (mask_factor>(FIXP_DBL)MAXVAL_DBL>>q_msk) ) {
      mask_factor = (FIXP_DBL)MAXVAL_DBL;
    }
    else {
      mask_factor = scaleValue(mask_factor, q_msk);
    }

    return (mask_factor);
}

static void FDKaacEnc_initSpreading(INT numPb,
                          FIXP_DBL *pbBarcValue,
                          FIXP_DBL *pbMaskLoFactor,
                          FIXP_DBL *pbMaskHiFactor,
                          FIXP_DBL *pbMaskLoFactorSprEn,
                          FIXP_DBL *pbMaskHiFactorSprEn,
                          const LONG bitrate,
                          const INT blockType)

{
    INT i;
    FIXP_DBL MASKLOWSPREN, MASKHIGHSPREN;

    FIXP_DBL MASKHIGH               = (FIXP_DBL)0x30000000; /* 1.5 in q29 */
    FIXP_DBL MASKLOW                = (FIXP_DBL)0x60000000; /* 3.0 in q29 */
    FIXP_DBL MASKLOWSPRENLONG       = (FIXP_DBL)0x60000000; /* 3.0 in q29 */
    FIXP_DBL MASKHIGHSPRENLONG      = (FIXP_DBL)0x40000000; /* 2.0 in q29 */
    FIXP_DBL MASKHIGHSPRENLONGLOWBR = (FIXP_DBL)0x30000000; /* 1.5 in q29 */
    FIXP_DBL MASKLOWSPRENSHORT      = (FIXP_DBL)0x40000000; /* 2.0 in q29 */
    FIXP_DBL MASKHIGHSPRENSHORT     = (FIXP_DBL)0x30000000; /* 1.5 in q29 */
    FIXP_DBL TEN                    = (FIXP_DBL)0x50000000; /* 10.0 in q27 */

    if (blockType != SHORT_WINDOW)
    {
        MASKLOWSPREN = MASKLOWSPRENLONG;
        MASKHIGHSPREN = (bitrate>20000)?MASKHIGHSPRENLONG:MASKHIGHSPRENLONGLOWBR;
    }
    else
    {
        MASKLOWSPREN = MASKLOWSPRENSHORT;
        MASKHIGHSPREN = MASKHIGHSPRENSHORT;
    }

    for(i=0; i<numPb; i++)
    {
        if (i > 0)
        {
            pbMaskHiFactor[i] = getMaskFactor(
                    fMult(MASKHIGH, (pbBarcValue[i] - pbBarcValue[i-1])), 23,
                    TEN, 27);

            pbMaskLoFactor[i-1] = getMaskFactor(
                    fMult(MASKLOW, (pbBarcValue[i] - pbBarcValue[i-1])), 23,
                    TEN, 27);

            pbMaskHiFactorSprEn[i] = getMaskFactor(
                    fMult(MASKHIGHSPREN, (pbBarcValue[i] - pbBarcValue[i-1])), 23,
                    TEN, 27);

            pbMaskLoFactorSprEn[i-1] = getMaskFactor(
                    fMult(MASKLOWSPREN, (pbBarcValue[i] - pbBarcValue[i-1])), 23,
                    TEN, 27);
        }
        else
        {
            pbMaskHiFactor[i]            = (FIXP_DBL)0;
            pbMaskLoFactor[numPb-1]      = (FIXP_DBL)0;
            pbMaskHiFactorSprEn[i]       = (FIXP_DBL)0;
            pbMaskLoFactorSprEn[numPb-1] = (FIXP_DBL)0;
        }
    }
}

static void FDKaacEnc_initBarcValues(INT numPb,
                           INT *pbOffset,
                           INT numLines,
                           INT samplingFrequency,
                           FIXP_DBL *pbBval)
{
    INT i;
    FIXP_DBL MAX_BARC = (FIXP_DBL)0x30000000; /* 24.0 in q25 */

    for(i=0; i<numPb; i++)
    {
        FIXP_DBL v1, v2, cur_bark;
        v1 = FDKaacEnc_BarcLineValue(numLines, pbOffset[i], samplingFrequency);
        v2 = FDKaacEnc_BarcLineValue(numLines, pbOffset[i+1], samplingFrequency);
        cur_bark = (v1 >> 1) + (v2 >> 1);
        pbBval[i] = fixMin(cur_bark, MAX_BARC);
    }
}

static void FDKaacEnc_initMinSnr(const LONG   bitrate,
                      const LONG   samplerate,
                      const INT    numLines,
                      const INT   *sfbOffset,
                      const INT    sfbActive,
                      const INT    blockType,
                      FIXP_DBL    *sfbMinSnrLdData)
{
    INT sfb;

    /* Fix conversion variables */
    INT qbfac, qperwin, qdiv, qpeprt_const, qpeprt;
    INT qtmp, qsnr, sfbWidth;

    FIXP_DBL MAX_BARC       = (FIXP_DBL)0x30000000; /* 24.0 in q25 */
    FIXP_DBL MAX_BARCP1     = (FIXP_DBL)0x32000000; /* 25.0 in q25 */
    FIXP_DBL BITS2PEFAC     = (FIXP_DBL)0x4b851eb8; /* 1.18 in q30 */
    FIXP_DBL PERS2P4        = (FIXP_DBL)0x624dd2f2; /* 0.024 in q36 */
    FIXP_DBL ONEP5          = (FIXP_DBL)0x60000000; /* 1.5 in q30 */
    FIXP_DBL MAX_SNR        = (FIXP_DBL)0x33333333; /* 0.8 in q30 */
    FIXP_DBL MIN_SNR        = (FIXP_DBL)0x003126e9; /* 0.003 in q30 */

    FIXP_DBL barcFactor, pePerWindow, pePart, barcWidth;
    FIXP_DBL pePart_const, tmp, snr, one_qsnr, one_point5;

    /* relative number of active barks */
    barcFactor = fDivNorm(fixMin(FDKaacEnc_BarcLineValue(numLines, sfbOffset[sfbActive], samplerate), MAX_BARC),
        MAX_BARCP1, &qbfac);

    qbfac = DFRACT_BITS-1-qbfac;

    pePerWindow = fDivNorm(bitrate, samplerate, &qperwin);
    qperwin = DFRACT_BITS-1-qperwin;
    pePerWindow = fMult(pePerWindow, BITS2PEFAC);                   qperwin = qperwin + 30 - (DFRACT_BITS-1);
    pePerWindow = fMult(pePerWindow, PERS2P4);                      qperwin = qperwin + 36 - (DFRACT_BITS-1);

    switch (numLines) {
      case 1024:
        qperwin = qperwin - 10;
        break;
      case 128:
        qperwin = qperwin - 7;
        break;
      case 512:
        qperwin = qperwin - 9;
        break;
      case 480:
        qperwin = qperwin - 9;
        pePerWindow = fMult(pePerWindow, FL2FXCONST_DBL(480.f/512.f));
        break;
    }

    /* for short blocks it is assumed that more bits are available */
    if (blockType == SHORT_WINDOW)
    {
        pePerWindow = fMult(pePerWindow, ONEP5);
        qperwin = qperwin + 30 - (DFRACT_BITS-1);
    }
    pePart_const = fDivNorm(pePerWindow, barcFactor, &qdiv);      qpeprt_const = qperwin - qbfac + DFRACT_BITS-1-qdiv;

    for (sfb = 0; sfb < sfbActive; sfb++)
    {
        barcWidth = FDKaacEnc_BarcLineValue(numLines, sfbOffset[sfb+1], samplerate) -
            FDKaacEnc_BarcLineValue(numLines, sfbOffset[sfb], samplerate);

        /* adapt to sfb bands */
        pePart = fMult(pePart_const, barcWidth); qpeprt = qpeprt_const + 25 - (DFRACT_BITS-1);

        /* pe -> snr calculation */
        sfbWidth = (sfbOffset[sfb+1] - sfbOffset[sfb]);
        pePart = fDivNorm(pePart, sfbWidth, &qdiv); qpeprt += DFRACT_BITS-1-qdiv;

        tmp = f2Pow(pePart, DFRACT_BITS-1-qpeprt, &qtmp);
        qtmp = DFRACT_BITS-1-qtmp;

        /* Subtract 1.5 */
        qsnr = fixMin(qtmp, 30);
        tmp = tmp >> (qtmp - qsnr);

        if((30+1-qsnr) > (DFRACT_BITS-1))
            one_point5 = (FIXP_DBL)0;
        else
            one_point5 = (FIXP_DBL)(ONEP5 >> (30+1-qsnr));

        snr = (tmp>>1) - (one_point5); qsnr -= 1;

        /* max(snr, 1.0) */
        if(qsnr > 0)
            one_qsnr = (FIXP_DBL)(1 << qsnr);
        else
            one_qsnr = (FIXP_DBL)0;

        snr = fixMax(one_qsnr, snr);

        /* 1/snr */
        snr = fDivNorm(one_qsnr, snr, &qsnr);
        qsnr = DFRACT_BITS-1-qsnr;
        snr = (qsnr > 30)? (snr>>(qsnr-30)):snr;

        /* upper limit is -1 dB */
        snr = (snr > MAX_SNR) ? MAX_SNR : snr;

        /* lower limit is -25 dB */
        snr = (snr < MIN_SNR) ? MIN_SNR : snr;
        snr = snr << 1;

        sfbMinSnrLdData[sfb] = CalcLdData(snr);
    }
}

AAC_ENCODER_ERROR FDKaacEnc_InitPsyConfiguration(INT   bitrate,
                                                 INT   samplerate,
                                                 INT   bandwidth,
                                                 INT   blocktype,
                                                 INT   granuleLength,
                                                 INT   useIS,
                                                 PSY_CONFIGURATION *psyConf,
                                                 FB_TYPE filterbank)
{
    AAC_ENCODER_ERROR ErrorStatus;
    INT      sfb;
    FIXP_DBL sfbBarcVal[MAX_SFB];
    const INT frameLengthLong = granuleLength;
    const INT frameLengthShort = granuleLength/TRANS_FAC;

    FDKmemclear(psyConf, sizeof(PSY_CONFIGURATION));
    psyConf->granuleLength = granuleLength;
    psyConf->filterbank = filterbank;

    psyConf->allowIS       = (useIS) && ( (bitrate/bandwidth) < 5 );

    /* init sfb table */
    ErrorStatus = FDKaacEnc_initSfbTable(samplerate,blocktype,granuleLength,psyConf->sfbOffset,&psyConf->sfbCnt);
    if (ErrorStatus != AAC_ENC_OK)
      return ErrorStatus;

    /* calculate barc values for each pb */
    FDKaacEnc_initBarcValues(psyConf->sfbCnt,
                   psyConf->sfbOffset,
                   psyConf->sfbOffset[psyConf->sfbCnt],
                   samplerate,
                   sfbBarcVal);

    FDKaacEnc_InitMinPCMResolution(psyConf->sfbCnt,
                         psyConf->sfbOffset,
                         psyConf->sfbPcmQuantThreshold);

    /* calculate spreading function */
    FDKaacEnc_initSpreading(psyConf->sfbCnt,
                  sfbBarcVal,
                  psyConf->sfbMaskLowFactor,
                  psyConf->sfbMaskHighFactor,
                  psyConf->sfbMaskLowFactorSprEn,
                  psyConf->sfbMaskHighFactorSprEn,
                  bitrate,
                  blocktype);

    /* init ratio */

    psyConf->maxAllowedIncreaseFactor = 2;                                                 /* integer */
    psyConf->minRemainingThresholdFactor = (FIXP_SGL)0x0148; /* FL2FXCONST_SGL(0.01f); */  /* fract   */

    psyConf->clipEnergy = (FIXP_DBL)0x773593ff; /* FL2FXCONST_DBL(1.0e9*NORM_PCM_ENERGY); */

    if (blocktype!=SHORT_WINDOW) {
        psyConf->lowpassLine = (INT)((2*bandwidth*frameLengthLong)/samplerate);
        psyConf->lowpassLineLFE = LFE_LOWPASS_LINE;
    }
    else {
        psyConf->lowpassLine = (INT)((2*bandwidth*frameLengthShort)/samplerate);
        psyConf->lowpassLineLFE = 0; /* LFE only in lonf blocks */
        /* psyConf->clipEnergy /= (TRANS_FAC * TRANS_FAC); */
        psyConf->clipEnergy >>= 6;
    }

    for (sfb = 0; sfb < psyConf->sfbCnt; sfb++){
        if (psyConf->sfbOffset[sfb] >= psyConf->lowpassLine)
            break;
    }
    psyConf->sfbActive = sfb;

    for (sfb = 0; sfb < psyConf->sfbCnt; sfb++){
        if (psyConf->sfbOffset[sfb] >= psyConf->lowpassLineLFE)
            break;
    }
    psyConf->sfbActiveLFE = sfb;

    /* calculate minSnr */
    FDKaacEnc_initMinSnr(bitrate,
               samplerate,
               psyConf->sfbOffset[psyConf->sfbCnt],
               psyConf->sfbOffset,
               psyConf->sfbActive,
               blocktype,
               psyConf->sfbMinSnrLdData);

    return AAC_ENC_OK;
}