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

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

(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

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

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

   Author(s):

   Description:

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

#include "nf_est.h"

#include "sbr_misc.h"

#include "genericStds.h"

/* smoothFilter[4]  = {0.05857864376269f, 0.2f, 0.34142135623731f, 0.4f}; */

static const FIXP_DBL smoothFilter[4] = {0x077f813d, 0x19999995, 0x2bb3b1f5,

                                         0x33333335};

/* static const INT smoothFilterLength = 4; */

static const FIXP_DBL QuantOffset = (INT)0xfc000000; /* ld64(0.25) */

#ifndef min

#define min(a, b) (a < b ? a : b)

#endif

#ifndef max

#define max(a, b) (a > b ? a : b)

#endif

#define NOISE_FLOOR_OFFSET_SCALING (4)

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

/*!

  \brief     The function applies smoothing to the noise levels.

  \return    none

*/

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

static void smoothingOfNoiseLevels(

    FIXP_DBL *NoiseLevels, /*!< pointer to noise-floor levels.*/

    INT nEnvelopes,        /*!< Number of noise floor envelopes.*/

    INT noNoiseBands, /*!< Number of noise bands for every noise floor envelope.

                       */

    FIXP_DBL prevNoiseLevels[NF_SMOOTHING_LENGTH]

                            [MAX_NUM_NOISE_VALUES], /*!< Previous noise floor

                                                       envelopes. */

    const FIXP_DBL *

        pSmoothFilter, /*!< filter used for smoothing the noise floor levels. */

    INT transientFlag) /*!< flag indicating if a transient is present*/

{

  INT i, band, env;

  FIXP_DBL accu;

  for (env = 0; env < nEnvelopes; env++) {

    if (transientFlag) {

      for (i = 0; i < NF_SMOOTHING_LENGTH; i++) {

        FDKmemcpy(prevNoiseLevels[i], NoiseLevels + env * noNoiseBands,

                  noNoiseBands * sizeof(FIXP_DBL));

      }

    } else {

      for (i = 1; i < NF_SMOOTHING_LENGTH; i++) {

        FDKmemcpy(prevNoiseLevels[i - 1], prevNoiseLevels[i],

                  noNoiseBands * sizeof(FIXP_DBL));

      }

      FDKmemcpy(prevNoiseLevels[NF_SMOOTHING_LENGTH - 1],

                NoiseLevels + env * noNoiseBands,

                noNoiseBands * sizeof(FIXP_DBL));

    }

    for (band = 0; band < noNoiseBands; band++) {

      accu = FL2FXCONST_DBL(0.0f);

      for (i = 0; i < NF_SMOOTHING_LENGTH; i++) {

        accu += fMultDiv2(pSmoothFilter[i], prevNoiseLevels[i][band]);

      }

      FDK_ASSERT((band + env * noNoiseBands) < MAX_NUM_NOISE_VALUES);

      NoiseLevels[band + env * noNoiseBands] = accu << 1;

    }

  }

}

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

/*!

  \brief     Does the noise floor level estiamtion.

  The noiseLevel samples are scaled by the factor 0.25

  \return    none

*/

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

static void qmfBasedNoiseFloorDetection(

    FIXP_DBL *noiseLevel,            /*!< Pointer to vector to

                                        store the noise levels

                                        in.*/

    FIXP_DBL **quotaMatrixOrig,      /*!< Matrix holding the quota

                                        values of the original. */

    SCHAR *indexVector,              /*!< Index vector to obtain the

                                        patched data. */

    INT startIndex,                  /*!< Start index. */

    INT stopIndex,                   /*!< Stop index. */

    INT startChannel,                /*!< Start channel of the current

                                        noise floor band.*/

    INT stopChannel,                 /*!< Stop channel of the current

                                        noise floor band. */

    FIXP_DBL ana_max_level,          /*!< Maximum level of the

                                        adaptive noise.*/

    FIXP_DBL noiseFloorOffset,       /*!< Noise floor offset. */

    INT missingHarmonicFlag,         /*!< Flag indicating if a

                                        strong tonal component

                                        is missing.*/

    FIXP_DBL weightFac,              /*!< Weightening factor for the

                                        difference between orig and sbr.

                                      */

    INVF_MODE diffThres,             /*!< Threshold value to control the

                                        inverse filtering decision.*/

    INVF_MODE inverseFilteringLevel) /*!< Inverse filtering

                                        level of the current

                                        band.*/

{

  INT scale, l, k;

  FIXP_DBL meanOrig = FL2FXCONST_DBL(0.0f), meanSbr = FL2FXCONST_DBL(0.0f),

           diff;

  FIXP_DBL invIndex = GetInvInt(stopIndex - startIndex);

  FIXP_DBL invChannel = GetInvInt(stopChannel - startChannel);

  FIXP_DBL accu;

  /*

  Calculate the mean value, over the current time segment, for the original, the

  HFR and the difference, over all channels in the current frequency range.

  */

  if (missingHarmonicFlag == 1) {

    for (l = startChannel; l < stopChannel; l++) {

      /* tonalityOrig */

      accu = FL2FXCONST_DBL(0.0f);

      for (k = startIndex; k < stopIndex; k++) {

        accu += fMultDiv2(quotaMatrixOrig[k][l], invIndex);

      }

      meanOrig = fixMax(meanOrig, (accu << 1));

      /* tonalitySbr */

      accu = FL2FXCONST_DBL(0.0f);

      for (k = startIndex; k < stopIndex; k++) {

        accu += fMultDiv2(quotaMatrixOrig[k][indexVector[l]], invIndex);

      }

      meanSbr = fixMax(meanSbr, (accu << 1));

    }

  } else {

    for (l = startChannel; l < stopChannel; l++) {

      /* tonalityOrig */

      accu = FL2FXCONST_DBL(0.0f);

      for (k = startIndex; k < stopIndex; k++) {

        accu += fMultDiv2(quotaMatrixOrig[k][l], invIndex);

      }

      meanOrig += fMult((accu << 1), invChannel);

      /* tonalitySbr */

      accu = FL2FXCONST_DBL(0.0f);

      for (k = startIndex; k < stopIndex; k++) {

        accu += fMultDiv2(quotaMatrixOrig[k][indexVector[l]], invIndex);

      }

      meanSbr += fMult((accu << 1), invChannel);

    }

  }

  /* Small fix to avoid noise during silent passages.*/

  if (meanOrig <= FL2FXCONST_DBL(0.000976562f * RELAXATION_FLOAT) &&

      meanSbr <= FL2FXCONST_DBL(0.000976562f * RELAXATION_FLOAT)) {

    meanOrig = FL2FXCONST_DBL(101.5936673f * RELAXATION_FLOAT);

    meanSbr = FL2FXCONST_DBL(101.5936673f * RELAXATION_FLOAT);

  }

  meanOrig = fixMax(meanOrig, RELAXATION);

  meanSbr = fixMax(meanSbr, RELAXATION);

  if (missingHarmonicFlag == 1 || inverseFilteringLevel == INVF_MID_LEVEL ||

      inverseFilteringLevel == INVF_LOW_LEVEL ||

      inverseFilteringLevel == INVF_OFF || inverseFilteringLevel <= diffThres) {

    diff = RELAXATION;

  } else {

    accu = fDivNorm(meanSbr, meanOrig, &scale);

    diff = fixMax(RELAXATION, fMult(RELAXATION_FRACT, fMult(weightFac, accu)) >>

                                  (RELAXATION_SHIFT - scale));

  }

  /*

   * noise Level is now a positive value, i.e.

   * the more harmonic the signal is the higher noise level,

   * this makes no sense so we change the sign.

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

  accu = fDivNorm(diff, meanOrig, &scale);

  scale -= 2;

  if ((scale > 0) && (accu > ((FIXP_DBL)MAXVAL_DBL) >> scale)) {

    *noiseLevel = (FIXP_DBL)MAXVAL_DBL;

  } else {

    *noiseLevel = scaleValue(accu, scale);

  }

  /*

   * Add a noise floor offset to compensate for bias in the detector

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

  if (!missingHarmonicFlag) {

    *noiseLevel = fixMin(fMult(*noiseLevel, noiseFloorOffset),

                         (FIXP_DBL)MAXVAL_DBL >> NOISE_FLOOR_OFFSET_SCALING)

                  << NOISE_FLOOR_OFFSET_SCALING;

  }

  /*

   * check to see that we don't exceed the maximum allowed level

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

  *noiseLevel =

      fixMin(*noiseLevel,

             ana_max_level); /* ana_max_level is scaled with factor 0.25 */

}

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

/*!

  \brief     Does the noise floor level estiamtion.

  The function calls the Noisefloor estimation function

  for the time segments decided based upon the transient

  information. The block is always divided into one or two segments.

  \return    none

*/

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

void FDKsbrEnc_sbrNoiseFloorEstimateQmf(

    HANDLE_SBR_NOISE_FLOOR_ESTIMATE

        h_sbrNoiseFloorEstimate, /*!< Handle to SBR_NOISE_FLOOR_ESTIMATE struct

                                  */

    const SBR_FRAME_INFO

        *frame_info, /*!< Time frequency grid of the current frame. */

    FIXP_DBL

        *noiseLevels, /*!< Pointer to vector to store the noise levels in.*/

    FIXP_DBL **quotaMatrixOrig, /*!< Matrix holding the quota values of the

                                   original. */

    SCHAR *indexVector,         /*!< Index vector to obtain the patched data. */

    INT missingHarmonicsFlag,   /*!< Flag indicating if a strong tonal component

                                   will be missing. */

    INT startIndex,             /*!< Start index. */

    UINT numberOfEstimatesPerFrame, /*!< The number of tonality estimates per

                                       frame. */

    int transientFrame, /*!< A flag indicating if a transient is present. */

    INVF_MODE *pInvFiltLevels, /*!< Pointer to the vector holding the inverse

                                  filtering levels. */

    UINT sbrSyntaxFlags)

{

  INT nNoiseEnvelopes, startPos[2], stopPos[2], env, band;

  INT noNoiseBands = h_sbrNoiseFloorEstimate->noNoiseBands;

  INT *freqBandTable = h_sbrNoiseFloorEstimate->freqBandTableQmf;

  nNoiseEnvelopes = frame_info->nNoiseEnvelopes;

  startPos[0] = startIndex;

  if (nNoiseEnvelopes == 1) {

    stopPos[0] = startIndex + min(numberOfEstimatesPerFrame, 2);

  } else {

    stopPos[0] = startIndex + 1;

    startPos[1] = startIndex + 1;

    stopPos[1] = startIndex + min(numberOfEstimatesPerFrame, 2);

  }

  /*

   * Estimate the noise floor.

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

  for (env = 0; env < nNoiseEnvelopes; env++) {

    for (band = 0; band < noNoiseBands; band++) {

      FDK_ASSERT((band + env * noNoiseBands) < MAX_NUM_NOISE_VALUES);

      qmfBasedNoiseFloorDetection(

          &noiseLevels[band + env * noNoiseBands], quotaMatrixOrig, indexVector,

          startPos[env], stopPos[env], freqBandTable[band],

          freqBandTable[band + 1], h_sbrNoiseFloorEstimate->ana_max_level,

          h_sbrNoiseFloorEstimate->noiseFloorOffset[band], missingHarmonicsFlag,

          h_sbrNoiseFloorEstimate->weightFac,

          h_sbrNoiseFloorEstimate->diffThres, pInvFiltLevels[band]);

    }

  }

  /*

   * Smoothing of the values.

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

  smoothingOfNoiseLevels(noiseLevels, nNoiseEnvelopes,

                         h_sbrNoiseFloorEstimate->noNoiseBands,

                         h_sbrNoiseFloorEstimate->prevNoiseLevels,

                         h_sbrNoiseFloorEstimate->smoothFilter, transientFrame);

  /* quantisation*/

  for (env = 0; env < nNoiseEnvelopes; env++) {

    for (band = 0; band < noNoiseBands; band++) {

      FDK_ASSERT((band + env * noNoiseBands) < MAX_NUM_NOISE_VALUES);

      noiseLevels[band + env * noNoiseBands] =

          (FIXP_DBL)NOISE_FLOOR_OFFSET_64 -

          (FIXP_DBL)CalcLdData(noiseLevels[band + env * noNoiseBands] +

                               (FIXP_DBL)1) +

          QuantOffset;

    }

  }

}

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

/*!

  \brief

  \return    errorCode, noError if successful

*/

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

static INT downSampleLoRes(INT *v_result,                 /*!<    */

                           INT num_result,                /*!<    */

                           const UCHAR *freqBandTableRef, /*!<    */

                           INT num_Ref)                   /*!<    */

{

  INT step;

  INT i, j;

  INT org_length, result_length;

  INT v_index[MAX_FREQ_COEFFS / 2];

  /* init */

  org_length = num_Ref;

  result_length = num_result;

  v_index[0] = 0; /* Always use left border */

  i = 0;

  while (org_length > 0) /* Create downsample vector */

  {

    i++;

    step = org_length / result_length; /* floor; */

    org_length = org_length - step;

    result_length--;

    v_index[i] = v_index[i - 1] + step;

  }

  if (i != num_result) /* Should never happen */

    return (1);        /* error downsampling */

  for (j = 0; j <= i;

       j++) /* Use downsample vector to index LoResolution vector. */

  {

    v_result[j] = freqBandTableRef[v_index[j]];

  }

  return (0);

}

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

/*!

  \brief    Initialize an instance of the noise floor level estimation module.

  \return    errorCode, noError if successful

*/

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

INT FDKsbrEnc_InitSbrNoiseFloorEstimate(

    HANDLE_SBR_NOISE_FLOOR_ESTIMATE

        h_sbrNoiseFloorEstimate, /*!< Handle to SBR_NOISE_FLOOR_ESTIMATE struct

                                  */

    INT ana_max_level,           /*!< Maximum level of the adaptive noise. */

    const UCHAR *freqBandTable,  /*!< Frequency band table. */

    INT nSfb,                    /*!< Number of frequency bands. */

    INT noiseBands,              /*!< Number of noise bands per octave. */

    INT noiseFloorOffset,        /*!< Noise floor offset. */

    INT timeSlots,               /*!< Number of time slots in a frame. */

    UINT useSpeechConfig /*!< Flag: adapt tuning parameters according to speech

                          */

) {

  INT i, qexp, qtmp;

  FIXP_DBL tmp, exp;

  FDKmemclear(h_sbrNoiseFloorEstimate, sizeof(SBR_NOISE_FLOOR_ESTIMATE));

  h_sbrNoiseFloorEstimate->smoothFilter = smoothFilter;

  if (useSpeechConfig) {

    h_sbrNoiseFloorEstimate->weightFac = (FIXP_DBL)MAXVAL_DBL;

    h_sbrNoiseFloorEstimate->diffThres = INVF_LOW_LEVEL;

  } else {

    h_sbrNoiseFloorEstimate->weightFac = FL2FXCONST_DBL(0.25f);

    h_sbrNoiseFloorEstimate->diffThres = INVF_MID_LEVEL;

  }

  h_sbrNoiseFloorEstimate->timeSlots = timeSlots;

  h_sbrNoiseFloorEstimate->noiseBands = noiseBands;

  /* h_sbrNoiseFloorEstimate->ana_max_level is scaled by 0.25  */

  switch (ana_max_level) {

    case 6:

      h_sbrNoiseFloorEstimate->ana_max_level = (FIXP_DBL)MAXVAL_DBL;

      break;

    case 3:

      h_sbrNoiseFloorEstimate->ana_max_level = FL2FXCONST_DBL(0.5);

      break;

    case -3:

      h_sbrNoiseFloorEstimate->ana_max_level = FL2FXCONST_DBL(0.125);

      break;

    default:

      /* Should not enter here */

      h_sbrNoiseFloorEstimate->ana_max_level = (FIXP_DBL)MAXVAL_DBL;

      break;

  }

  /*

    calculate number of noise bands and allocate

  */

  if (FDKsbrEnc_resetSbrNoiseFloorEstimate(h_sbrNoiseFloorEstimate,

                                           freqBandTable, nSfb))

    return (1);

  if (noiseFloorOffset == 0) {

    tmp = ((FIXP_DBL)MAXVAL_DBL) >> NOISE_FLOOR_OFFSET_SCALING;

  } else {

    /* noiseFloorOffset has to be smaller than 12, because

       the result of the calculation below must be smaller than 1:

       (2^(noiseFloorOffset/3))*2^4<1                                        */

    FDK_ASSERT(noiseFloorOffset < 12);

    /* Assumes the noise floor offset in tuning table are in q31    */

    /* Change the qformat here when non-zero values would be filled */

    exp = fDivNorm((FIXP_DBL)noiseFloorOffset, 3, &qexp);

    tmp = fPow(2, DFRACT_BITS - 1, exp, qexp, &qtmp);

    tmp = scaleValue(tmp, qtmp - NOISE_FLOOR_OFFSET_SCALING);

  }

  for (i = 0; i < h_sbrNoiseFloorEstimate->noNoiseBands; i++) {

    h_sbrNoiseFloorEstimate->noiseFloorOffset[i] = tmp;

  }

  return (0);

}

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

/*!

  \brief     Resets the current instance of the noise floor estiamtion

          module.

  \return    errorCode, noError if successful

*/

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

INT FDKsbrEnc_resetSbrNoiseFloorEstimate(

    HANDLE_SBR_NOISE_FLOOR_ESTIMATE

        h_sbrNoiseFloorEstimate, /*!< Handle to SBR_NOISE_FLOOR_ESTIMATE struct

                                  */

    const UCHAR *freqBandTable,  /*!< Frequency band table. */

    INT nSfb /*!< Number of bands in the frequency band table. */

) {

  INT k2, kx;

  /*

   * Calculate number of noise bands

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

  k2 = freqBandTable[nSfb];

  kx = freqBandTable[0];

  if (h_sbrNoiseFloorEstimate->noiseBands == 0) {

    h_sbrNoiseFloorEstimate->noNoiseBands = 1;

  } else {

    /*

     * Calculate number of noise bands 1,2 or 3 bands/octave

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

    FIXP_DBL tmp, ratio, lg2;

    INT ratio_e, qlg2, nNoiseBands;

    ratio = fDivNorm(k2, kx, &ratio_e);

    lg2 = fLog2(ratio, ratio_e, &qlg2);

    tmp = fMult((FIXP_DBL)(h_sbrNoiseFloorEstimate->noiseBands << 24), lg2);

    tmp = scaleValue(tmp, qlg2 - 23);

    nNoiseBands = (INT)((tmp + (FIXP_DBL)1) >> 1);

    if (nNoiseBands > MAX_NUM_NOISE_COEFFS) {

      nNoiseBands = MAX_NUM_NOISE_COEFFS;

    }

    if (nNoiseBands == 0) {

      nNoiseBands = 1;

    }

    h_sbrNoiseFloorEstimate->noNoiseBands = nNoiseBands;

  }

  return (downSampleLoRes(h_sbrNoiseFloorEstimate->freqBandTableQmf,

                          h_sbrNoiseFloorEstimate->noNoiseBands, freqBandTable,

                          nSfb));

}

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

/*!

  \brief     Deletes the current instancce of the noise floor level

  estimation module.

  \return    none

*/

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

void FDKsbrEnc_deleteSbrNoiseFloorEstimate(

    HANDLE_SBR_NOISE_FLOOR_ESTIMATE

        h_sbrNoiseFloorEstimate) /*!< Handle to SBR_NOISE_FLOOR_ESTIMATE struct

                                  */

{

  if (h_sbrNoiseFloorEstimate) {

    /*

      nothing to do

    */

  }

}