ms_stereo.cpp - Android社区 - https://www.androidos.net.cn/

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

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)
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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
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You must retain the complete text of this software license in redistributions of the FDK AAC Codec or
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This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright holders and contributors
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5.    CONTACT INFORMATION

Fraunhofer Institute for Integrated Circuits IIS
Attention: Audio and Multimedia Departments - FDK AAC LL
Am Wolfsmantel 33
91058 Erlangen, Germany

www.iis.fraunhofer.de/amm
amm-info@iis.fraunhofer.de
----------------------------------------------------------------------------------------------------------- */

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

Initial author:       M.Werner
   contents/description: MS stereo processing

******************************************************************************/
#include "ms_stereo.h"

#include "psy_const.h"

/* static const float scaleMinThres = 1.0f; */ /* 0.75f for 3db boost */

void FDKaacEnc_MsStereoProcessing(PSY_DATA   *RESTRICT psyData[(2)],
                        PSY_OUT_CHANNEL* psyOutChannel[2],
                        const INT  *isBook,
                        INT        *msDigest,       /* output */
                        INT        *msMask,         /* output */
                        const INT   sfbCnt,
                        const INT   sfbPerGroup,
                        const INT   maxSfbPerGroup,
                        const INT  *sfbOffset)
{
    FIXP_DBL        *sfbEnergyLeft = psyData[0]->sfbEnergy.Long;                       /* modified where msMask==1 */
    FIXP_DBL        *sfbEnergyRight = psyData[1]->sfbEnergy.Long;                      /* modified where msMask==1 */
    const FIXP_DBL  *sfbEnergyMid = psyData[0]->sfbEnergyMS.Long;
    const FIXP_DBL  *sfbEnergySide = psyData[1]->sfbEnergyMS.Long;
    FIXP_DBL        *sfbThresholdLeft = psyData[0]->sfbThreshold.Long;                 /* modified where msMask==1 */
    FIXP_DBL        *sfbThresholdRight = psyData[1]->sfbThreshold.Long;                /* modified where msMask==1 */

FIXP_DBL        *sfbSpreadEnLeft = psyData[0]->sfbSpreadEnergy.Long;
    FIXP_DBL        *sfbSpreadEnRight = psyData[1]->sfbSpreadEnergy.Long;

FIXP_DBL        *sfbEnergyLeftLdData = psyOutChannel[0]->sfbEnergyLdData;        /* modified where msMask==1 */
    FIXP_DBL        *sfbEnergyRightLdData = psyOutChannel[1]->sfbEnergyLdData;       /* modified where msMask==1 */
    FIXP_DBL        *sfbEnergyMidLdData = psyData[0]->sfbEnergyMSLdData;
    FIXP_DBL        *sfbEnergySideLdData = psyData[1]->sfbEnergyMSLdData;
    FIXP_DBL        *sfbThresholdLeftLdData = psyOutChannel[0]->sfbThresholdLdData;  /* modified where msMask==1 */
    FIXP_DBL        *sfbThresholdRightLdData = psyOutChannel[1]->sfbThresholdLdData; /* modified where msMask==1 */

FIXP_DBL        *mdctSpectrumLeft = psyData[0]->mdctSpectrum;                      /* modified where msMask==1 */
    FIXP_DBL        *mdctSpectrumRight = psyData[1]->mdctSpectrum;                     /* modified where msMask==1 */

INT             sfb,sfboffs, j;           /* loop counters         */
    FIXP_DBL        pnlrLdData, pnmsLdData;
    FIXP_DBL        minThresholdLdData;
    FIXP_DBL        minThreshold;
    INT             useMS;

INT             msMaskTrueSomewhere = 0;  /* to determine msDigest */
    INT             numMsMaskFalse = 0;       /* number of non-intensity bands where L/R coding is used */

for(sfb=0; sfb<sfbCnt; sfb+=sfbPerGroup) {
      for(sfboffs=0;sfboffs<maxSfbPerGroup;sfboffs++) {

if ( (isBook==NULL) ? 1 : (isBook[sfb+sfboffs] == 0) ) {
          FIXP_DBL tmp;

/*
          minThreshold=min(sfbThresholdLeft[sfb+sfboffs], sfbThresholdRight[sfb+sfboffs])*scaleMinThres;
          pnlr = (sfbThresholdLeft[sfb+sfboffs]/
                 max(sfbEnergyLeft[sfb+sfboffs],sfbThresholdLeft[sfb+sfboffs]))*
                 (sfbThresholdRight[sfb+sfboffs]/
                 max(sfbEnergyRight[sfb+sfboffs],sfbThresholdRight[sfb+sfboffs]));
          pnms = (minThreshold/max(sfbEnergyMid[sfb+sfboffs],minThreshold))*
                 (minThreshold/max(sfbEnergySide[sfb+sfboffs],minThreshold));
          useMS = (pnms > pnlr);
*/

/* we assume that scaleMinThres == 1.0f and we can drop it */
          minThresholdLdData = fixMin(sfbThresholdLeftLdData[sfb+sfboffs], sfbThresholdRightLdData[sfb+sfboffs]);

/* pnlrLdData = sfbThresholdLeftLdData[sfb+sfboffs] -
                        max(sfbEnergyLeftLdData[sfb+sfboffs], sfbThresholdLeftLdData[sfb+sfboffs]) +
                        sfbThresholdRightLdData[sfb+sfboffs] -
                        max(sfbEnergyRightLdData[sfb+sfboffs], sfbThresholdRightLdData[sfb+sfboffs]); */
          tmp = fixMax(sfbEnergyLeftLdData[sfb+sfboffs], sfbThresholdLeftLdData[sfb+sfboffs]);
          pnlrLdData = (sfbThresholdLeftLdData[sfb+sfboffs]>>1) - (tmp>>1);
          pnlrLdData = pnlrLdData + (sfbThresholdRightLdData[sfb+sfboffs]>>1);
          tmp = fixMax(sfbEnergyRightLdData[sfb+sfboffs], sfbThresholdRightLdData[sfb+sfboffs]);
          pnlrLdData = pnlrLdData - (tmp>>1);

/* pnmsLdData = minThresholdLdData - max(sfbEnergyMidLdData[sfb+sfboffs], minThresholdLdData) +
                        minThresholdLdData - max(sfbEnergySideLdData[sfb+sfboffs], minThresholdLdData); */
          tmp = fixMax(sfbEnergyMidLdData[sfb+sfboffs], minThresholdLdData);
          pnmsLdData = minThresholdLdData - (tmp>>1);
          tmp = fixMax(sfbEnergySideLdData[sfb+sfboffs], minThresholdLdData);
          pnmsLdData = pnmsLdData - (tmp>>1);
          useMS = (pnmsLdData > (pnlrLdData));

if (useMS) {
            msMask[sfb+sfboffs] = 1;
            msMaskTrueSomewhere = 1;
            for(j=sfbOffset[sfb+sfboffs]; j<sfbOffset[sfb+sfboffs+1]; j++) {
              FIXP_DBL specL, specR;
              specL = mdctSpectrumLeft[j]>>1;
              specR = mdctSpectrumRight[j]>>1;
              mdctSpectrumLeft[j] = specL + specR;
              mdctSpectrumRight[j] = specL - specR;
            }
            minThreshold = fixMin(sfbThresholdLeft[sfb+sfboffs], sfbThresholdRight[sfb+sfboffs]);
            sfbThresholdLeft[sfb+sfboffs] = sfbThresholdRight[sfb+sfboffs] = minThreshold;
            sfbThresholdLeftLdData[sfb+sfboffs] = sfbThresholdRightLdData[sfb+sfboffs] = minThresholdLdData;
            sfbEnergyLeft[sfb+sfboffs] = sfbEnergyMid[sfb+sfboffs];
            sfbEnergyRight[sfb+sfboffs] = sfbEnergySide[sfb+sfboffs];
            sfbEnergyLeftLdData[sfb+sfboffs] = sfbEnergyMidLdData[sfb+sfboffs];
            sfbEnergyRightLdData[sfb+sfboffs] = sfbEnergySideLdData[sfb+sfboffs];

sfbSpreadEnLeft[sfb+sfboffs] = sfbSpreadEnRight[sfb+sfboffs] =
                     fixMin( sfbSpreadEnLeft[sfb+sfboffs],
                             sfbSpreadEnRight[sfb+sfboffs] ) >> 1;

}
          else {
            msMask[sfb+sfboffs] = 0;
            numMsMaskFalse++;
          } /* useMS */
        } /* isBook */
        else {
          /* keep mDigest from IS module */
          if (msMask[sfb+sfboffs]) {
            msMaskTrueSomewhere = 1;
          }
          /* prohibit MS_MASK_ALL in combination with IS */
          numMsMaskFalse = 9;
        } /* isBook */
      } /* sfboffs */
    } /* sfb */

if(msMaskTrueSomewhere == 1) {
      if ((numMsMaskFalse == 0) || ((numMsMaskFalse < maxSfbPerGroup) && (numMsMaskFalse < 9))) {
        *msDigest = SI_MS_MASK_ALL;
        /* loop through M/S bands; if msMask==0, set it to 1 and apply M/S */
        for (sfb = 0; sfb < sfbCnt; sfb += sfbPerGroup) {
          for (sfboffs = 0; sfboffs < maxSfbPerGroup; sfboffs++) {
            if (( (isBook == NULL) ? 1 : (isBook[sfb+sfboffs] == 0) ) && (msMask[sfb+sfboffs] == 0)) {
              msMask[sfb+sfboffs] = 1;
              /* apply M/S coding */
              for(j=sfbOffset[sfb+sfboffs]; j<sfbOffset[sfb+sfboffs+1]; j++) {
                FIXP_DBL specL, specR;
                specL = mdctSpectrumLeft[j]>>1;
                specR = mdctSpectrumRight[j]>>1;
                mdctSpectrumLeft[j] = specL + specR;
                mdctSpectrumRight[j] = specL - specR;
              }
              minThreshold = fixMin(sfbThresholdLeft[sfb+sfboffs], sfbThresholdRight[sfb+sfboffs]);
              sfbThresholdLeft[sfb+sfboffs] = sfbThresholdRight[sfb+sfboffs] = minThreshold;
              minThresholdLdData = fixMin(sfbThresholdLeftLdData[sfb+sfboffs], sfbThresholdRightLdData[sfb+sfboffs]);
              sfbThresholdLeftLdData[sfb+sfboffs] = sfbThresholdRightLdData[sfb+sfboffs] = minThresholdLdData;
              sfbEnergyLeft[sfb+sfboffs] = sfbEnergyMid[sfb+sfboffs];
              sfbEnergyRight[sfb+sfboffs] = sfbEnergySide[sfb+sfboffs];
              sfbEnergyLeftLdData[sfb+sfboffs] = sfbEnergyMidLdData[sfb+sfboffs];
              sfbEnergyRightLdData[sfb+sfboffs] = sfbEnergySideLdData[sfb+sfboffs];

sfbSpreadEnLeft[sfb+sfboffs] = sfbSpreadEnRight[sfb+sfboffs] =
                       fixMin( sfbSpreadEnLeft[sfb+sfboffs],
                               sfbSpreadEnRight[sfb+sfboffs] ) >> 1;
            }
          }
        }
      } else {
        *msDigest = SI_MS_MASK_SOME;
      }
    } else {
      *msDigest = SI_MS_MASK_NONE;
    }
}

C++程序 | 252行 | 13.05 KB

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