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

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

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

/**************************** AAC encoder library ******************************

   Author(s):   M. Lohwasser

   Description: pns.c

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

#include "aacenc_pns.h"

#include "psy_data.h"

#include "pnsparam.h"

#include "noisedet.h"

#include "bit_cnt.h"

#include "interface.h"

/* minCorrelationEnergy = (1.0e-10f)^2 ~ 2^-67 = 2^-47 * 2^-20 */

static const FIXP_DBL minCorrelationEnergy =

    FL2FXCONST_DBL(0.0); /* FL2FXCONST_DBL((float)FDKpow(2.0,-47)); */

/* noiseCorrelationThresh = 0.6^2 */

static const FIXP_DBL noiseCorrelationThresh = FL2FXCONST_DBL(0.36);

static void FDKaacEnc_FDKaacEnc_noiseDetection(

    PNS_CONFIG *pnsConf, PNS_DATA *pnsData, const INT sfbActive,

    const INT *sfbOffset, INT tnsOrder, INT tnsPredictionGain, INT tnsActive,

    FIXP_DBL *mdctSpectrum, INT *sfbMaxScaleSpec, FIXP_SGL *sfbtonality);

static void FDKaacEnc_CalcNoiseNrgs(const INT sfbActive, INT *pnsFlag,

                                    FIXP_DBL *sfbEnergyLdData, INT *noiseNrg);

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

    functionname: initPnsConfiguration

    description:  fill pnsConf with pns parameters

    returns:      error status

    input:        PNS Config struct (modified)

                  bitrate, samplerate, usePns,

                  number of sfb's, pointer to sfb offset

    output:       error code

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

AAC_ENCODER_ERROR FDKaacEnc_InitPnsConfiguration(

    PNS_CONFIG *pnsConf, INT bitRate, INT sampleRate, INT usePns, INT sfbCnt,

    const INT *sfbOffset, const INT numChan, const INT isLC) {

  AAC_ENCODER_ERROR ErrorStatus;

  /* init noise detection */

  ErrorStatus = FDKaacEnc_GetPnsParam(&pnsConf->np, bitRate, sampleRate, sfbCnt,

                                      sfbOffset, &usePns, numChan, isLC);

  if (ErrorStatus != AAC_ENC_OK) return ErrorStatus;

  pnsConf->minCorrelationEnergy = minCorrelationEnergy;

  pnsConf->noiseCorrelationThresh = noiseCorrelationThresh;

  pnsConf->usePns = usePns;

  return AAC_ENC_OK;

}

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

    functionname: FDKaacEnc_PnsDetect

    description:  do decision, if PNS shall used or not

    returns:

    input:        pns config structure

                  pns data structure (modified),

                  lastWindowSequence (long or short blocks)

                  sfbActive

                  pointer to Sfb Energy, Threshold, Offset

                  pointer to mdct Spectrum

                  length of each group

                  pointer to tonality calculated in chaosmeasure

                  tns order and prediction gain

                  calculated noiseNrg at active PNS

    output:       pnsFlag in pns data structure

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

void FDKaacEnc_PnsDetect(PNS_CONFIG *pnsConf, PNS_DATA *pnsData,

                         const INT lastWindowSequence, const INT sfbActive,

                         const INT maxSfbPerGroup, FIXP_DBL *sfbThresholdLdData,

                         const INT *sfbOffset, FIXP_DBL *mdctSpectrum,

                         INT *sfbMaxScaleSpec, FIXP_SGL *sfbtonality,

                         INT tnsOrder, INT tnsPredictionGain, INT tnsActive,

                         FIXP_DBL *sfbEnergyLdData, INT *noiseNrg)

{

  int sfb;

  int startNoiseSfb;

  /* Reset pns info. */

  FDKmemclear(pnsData->pnsFlag, sizeof(pnsData->pnsFlag));

  for (sfb = 0; sfb < MAX_GROUPED_SFB; sfb++) {

    noiseNrg[sfb] = NO_NOISE_PNS;

  }

  /* Disable PNS and skip detection in certain cases. */

  if (pnsConf->usePns == 0) {

    return;

  } else {

    /* AAC - LC core encoder */

    if ((pnsConf->np.detectionAlgorithmFlags & IS_LOW_COMPLEXITY) &&

        (lastWindowSequence == SHORT_WINDOW)) {

      return;

    }

    /* AAC - (E)LD core encoder */

    if (!(pnsConf->np.detectionAlgorithmFlags & IS_LOW_COMPLEXITY) &&

        (pnsConf->np.detectionAlgorithmFlags & JUST_LONG_WINDOW) &&

        (lastWindowSequence != LONG_WINDOW)) {

      return;

    }

  }

  /*

    call noise detection

  */

  FDKaacEnc_FDKaacEnc_noiseDetection(

      pnsConf, pnsData, sfbActive, sfbOffset, tnsOrder, tnsPredictionGain,

      tnsActive, mdctSpectrum, sfbMaxScaleSpec, sfbtonality);

  /* set startNoiseSfb (long) */

  startNoiseSfb = pnsConf->np.startSfb;

  /* Set noise substitution status */

  for (sfb = 0; sfb < sfbActive; sfb++) {

    /* No PNS below startNoiseSfb */

    if (sfb < startNoiseSfb) {

      pnsData->pnsFlag[sfb] = 0;

      continue;

    }

    /*

      do noise substitution if

      fuzzy measure is high enough

      sfb freq > minimum sfb freq

      signal in coder band is not masked

    */

    if ((pnsData->noiseFuzzyMeasure[sfb] > FL2FXCONST_SGL(0.5)) &&

        ((sfbThresholdLdData[sfb] +

          FL2FXCONST_DBL(0.5849625f /

                         64.0f)) /* thr * 1.5 = thrLd +ld(1.5)/64 */

         < sfbEnergyLdData[sfb])) {

      /*

        mark in psyout flag array that we will code

        this band with PNS

      */

      pnsData->pnsFlag[sfb] = 1; /* PNS_ON */

    } else {

      pnsData->pnsFlag[sfb] = 0; /* PNS_OFF */

    }

    /* no PNS if LTP is active */

  }

  /* avoid PNS holes */

  if ((pnsData->noiseFuzzyMeasure[0] > FL2FXCONST_SGL(0.5f)) &&

      (pnsData->pnsFlag[1])) {

    pnsData->pnsFlag[0] = 1;

  }

  for (sfb = 1; sfb < maxSfbPerGroup - 1; sfb++) {

    if ((pnsData->noiseFuzzyMeasure[sfb] > pnsConf->np.gapFillThr) &&

        (pnsData->pnsFlag[sfb - 1]) && (pnsData->pnsFlag[sfb + 1])) {

      pnsData->pnsFlag[sfb] = 1;

    }

  }

  if (maxSfbPerGroup > 0) {

    /* avoid PNS hole */

    if ((pnsData->noiseFuzzyMeasure[maxSfbPerGroup - 1] >

         pnsConf->np.gapFillThr) &&

        (pnsData->pnsFlag[maxSfbPerGroup - 2])) {

      pnsData->pnsFlag[maxSfbPerGroup - 1] = 1;

    }

    /* avoid single PNS band */

    if (pnsData->pnsFlag[maxSfbPerGroup - 2] == 0) {

      pnsData->pnsFlag[maxSfbPerGroup - 1] = 0;

    }

  }

  /* avoid single PNS bands */

  if (pnsData->pnsFlag[1] == 0) {

    pnsData->pnsFlag[0] = 0;

  }

  for (sfb = 1; sfb < maxSfbPerGroup - 1; sfb++) {

    if ((pnsData->pnsFlag[sfb - 1] == 0) && (pnsData->pnsFlag[sfb + 1] == 0)) {

      pnsData->pnsFlag[sfb] = 0;

    }

  }

  /*

    calculate noiseNrg's

  */

  FDKaacEnc_CalcNoiseNrgs(sfbActive, pnsData->pnsFlag, sfbEnergyLdData,

                          noiseNrg);

}

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

    functionname:FDKaacEnc_FDKaacEnc_noiseDetection

    description: wrapper for noisedet.c

    returns:

    input:       pns config structure

                 pns data structure (modified),

                 sfbActive

                 tns order and prediction gain

                 pointer to mdct Spectrumand Sfb Energy

                 pointer to Sfb tonality

    output:      noiseFuzzyMeasure in structure pnsData

                 flags tonal / nontonal

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

static void FDKaacEnc_FDKaacEnc_noiseDetection(

    PNS_CONFIG *pnsConf, PNS_DATA *pnsData, const INT sfbActive,

    const INT *sfbOffset, int tnsOrder, INT tnsPredictionGain, INT tnsActive,

    FIXP_DBL *mdctSpectrum, INT *sfbMaxScaleSpec, FIXP_SGL *sfbtonality) {

  INT condition = TRUE;

  if (!(pnsConf->np.detectionAlgorithmFlags & IS_LOW_COMPLEXITY)) {

    condition = (tnsOrder > 3);

  }

  /*

  no PNS if heavy TNS activity

  clear pnsData->noiseFuzzyMeasure

  */

  if ((pnsConf->np.detectionAlgorithmFlags & USE_TNS_GAIN_THR) &&

      (tnsPredictionGain >= pnsConf->np.tnsGainThreshold) && condition &&

      !((pnsConf->np.detectionAlgorithmFlags & USE_TNS_PNS) &&

        (tnsPredictionGain >= pnsConf->np.tnsPNSGainThreshold) &&

        (tnsActive))) {

    /* clear all noiseFuzzyMeasure */

    FDKmemclear(pnsData->noiseFuzzyMeasure, sfbActive * sizeof(FIXP_SGL));

  } else {

    /*

    call noise detection, output in pnsData->noiseFuzzyMeasure,

    use real mdct spectral data

    */

    FDKaacEnc_noiseDetect(mdctSpectrum, sfbMaxScaleSpec, sfbActive, sfbOffset,

                          pnsData->noiseFuzzyMeasure, &pnsConf->np,

                          sfbtonality);

  }

}

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

    functionname:FDKaacEnc_CalcNoiseNrgs

    description: Calculate the NoiseNrg's

    returns:

    input:       sfbActive

                 if pnsFlag calculate NoiseNrg

                 pointer to sfbEnergy and groupLen

                 pointer to noiseNrg (modified)

    output:      noiseNrg's in pnsFlaged sfb's

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

static void FDKaacEnc_CalcNoiseNrgs(const INT sfbActive, INT *RESTRICT pnsFlag,

                                    FIXP_DBL *RESTRICT sfbEnergyLdData,

                                    INT *RESTRICT noiseNrg) {

  int sfb;

  INT tmp = (-LOG_NORM_PCM) << 2;

  for (sfb = 0; sfb < sfbActive; sfb++) {

    if (pnsFlag[sfb]) {

      INT nrg = (-sfbEnergyLdData[sfb] + FL2FXCONST_DBL(0.5f / 64.0f)) >>

                (DFRACT_BITS - 1 - 7);

      noiseNrg[sfb] = tmp - nrg;

    }

  }

}

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

    functionname:FDKaacEnc_CodePnsChannel

    description: Execute pns decission

    returns:

    input:       sfbActive

                 pns config structure

                 use PNS if pnsFlag

                 pointer to Sfb Energy, noiseNrg, Threshold

    output:      set sfbThreshold high to code pe with 0,

                 noiseNrg marks flag for pns coding

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

void FDKaacEnc_CodePnsChannel(const INT sfbActive, PNS_CONFIG *pnsConf,

                              INT *RESTRICT pnsFlag,

                              FIXP_DBL *RESTRICT sfbEnergyLdData,

                              INT *RESTRICT noiseNrg,

                              FIXP_DBL *RESTRICT sfbThresholdLdData) {

  INT sfb;

  INT lastiNoiseEnergy = 0;

  INT firstPNSband = 1; /* TRUE for first PNS-coded band */

  /* no PNS */

  if (!pnsConf->usePns) {

    for (sfb = 0; sfb < sfbActive; sfb++) {

      /* no PNS coding */

      noiseNrg[sfb] = NO_NOISE_PNS;

    }

    return;

  }

  /* code PNS */

  for (sfb = 0; sfb < sfbActive; sfb++) {

    if (pnsFlag[sfb]) {

      /* high sfbThreshold causes pe = 0 */

      if (noiseNrg[sfb] != NO_NOISE_PNS)

        sfbThresholdLdData[sfb] =

            sfbEnergyLdData[sfb] + FL2FXCONST_DBL(1.0f / LD_DATA_SCALING);

      /* set noiseNrg in valid region */

      if (!firstPNSband) {

        INT deltaiNoiseEnergy = noiseNrg[sfb] - lastiNoiseEnergy;

        if (deltaiNoiseEnergy > CODE_BOOK_PNS_LAV)

          noiseNrg[sfb] -= deltaiNoiseEnergy - CODE_BOOK_PNS_LAV;

        else if (deltaiNoiseEnergy < -CODE_BOOK_PNS_LAV)

          noiseNrg[sfb] -= deltaiNoiseEnergy + CODE_BOOK_PNS_LAV;

      } else {

        firstPNSband = 0;

      }

      lastiNoiseEnergy = noiseNrg[sfb];

    } else {

      /* no PNS coding */

      noiseNrg[sfb] = NO_NOISE_PNS;

    }

  }

}

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

    functionname:FDKaacEnc_PreProcessPnsChannelPair

    description: Calculate the correlation of noise in a channel pair

    returns:

    input:       sfbActive

                 pointer to sfb energies left, right and mid channel

                 pns config structure

                 pns data structure left and right (modified)

    output:      noiseEnergyCorrelation in pns data structure

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

void FDKaacEnc_PreProcessPnsChannelPair(

    const INT sfbActive, FIXP_DBL *RESTRICT sfbEnergyLeft,

    FIXP_DBL *RESTRICT sfbEnergyRight, FIXP_DBL *RESTRICT sfbEnergyLeftLD,

    FIXP_DBL *RESTRICT sfbEnergyRightLD, FIXP_DBL *RESTRICT sfbEnergyMid,

    PNS_CONFIG *RESTRICT pnsConf, PNS_DATA *pnsDataLeft,

    PNS_DATA *pnsDataRight) {

  INT sfb;

  FIXP_DBL ccf;

  if (!pnsConf->usePns) return;

  FIXP_DBL *RESTRICT pNoiseEnergyCorrelationL =

      pnsDataLeft->noiseEnergyCorrelation;

  FIXP_DBL *RESTRICT pNoiseEnergyCorrelationR =

      pnsDataRight->noiseEnergyCorrelation;

  for (sfb = 0; sfb < sfbActive; sfb++) {

    FIXP_DBL quot = (sfbEnergyLeftLD[sfb] >> 1) + (sfbEnergyRightLD[sfb] >> 1);

    if (quot < FL2FXCONST_DBL(-32.0f / (float)LD_DATA_SCALING))

      ccf = FL2FXCONST_DBL(0.0f);

    else {

      FIXP_DBL accu =

          sfbEnergyMid[sfb] -

          (((sfbEnergyLeft[sfb] >> 1) + (sfbEnergyRight[sfb] >> 1)) >> 1);

      INT sign = (accu < FL2FXCONST_DBL(0.0f)) ? 1 : 0;

      accu = fixp_abs(accu);

      ccf = CalcLdData(accu) +

            FL2FXCONST_DBL((float)1.0f / (float)LD_DATA_SCALING) -

            quot; /* ld(accu*2) = ld(accu) + 1 */

      ccf = (ccf >= FL2FXCONST_DBL(0.0))

                ? ((FIXP_DBL)MAXVAL_DBL)

                : (sign) ? -CalcInvLdData(ccf) : CalcInvLdData(ccf);

    }

    pNoiseEnergyCorrelationL[sfb] = ccf;

    pNoiseEnergyCorrelationR[sfb] = ccf;

  }

}

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

    functionname:FDKaacEnc_PostProcessPnsChannelPair

    description: if PNS used at left and right channel,

                 use msMask to flag correlation

    returns:

    input:       sfbActive

                 pns config structure

                 pns data structure left and right (modified)

                 pointer to msMask, flags correlation by pns coding (modified)

                 Digest of MS coding

    output:      pnsFlag in pns data structure,

                 msFlag in msMask (flags correlation)

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

void FDKaacEnc_PostProcessPnsChannelPair(const INT sfbActive,

                                         PNS_CONFIG *pnsConf,

                                         PNS_DATA *pnsDataLeft,

                                         PNS_DATA *pnsDataRight,

                                         INT *RESTRICT msMask, INT *msDigest) {

  INT sfb;

  if (!pnsConf->usePns) return;

  for (sfb = 0; sfb < sfbActive; sfb++) {

    /*

      MS post processing

    */

    if (msMask[sfb]) {

      if ((pnsDataLeft->pnsFlag[sfb]) && (pnsDataRight->pnsFlag[sfb])) {

        /* AAC only: Standard */

        /* do this to avoid ms flags in layers that should not have it */

        if (pnsDataLeft->noiseEnergyCorrelation[sfb] <=

            pnsConf->noiseCorrelationThresh) {

          msMask[sfb] = 0;

          *msDigest = MS_SOME;

        }

      } else {

        /*

          No PNS coding

        */

        pnsDataLeft->pnsFlag[sfb] = 0;

        pnsDataRight->pnsFlag[sfb] = 0;

      }

    }

    /*

      Use MS flag to signal noise correlation if

      pns is active in both channels

    */

    if ((pnsDataLeft->pnsFlag[sfb]) && (pnsDataRight->pnsFlag[sfb])) {

      if (pnsDataLeft->noiseEnergyCorrelation[sfb] >

          pnsConf->noiseCorrelationThresh) {

        msMask[sfb] = 1;

        *msDigest = MS_SOME;

      }

    }

  }

}