xref: /external/aac/libAACenc/src/tonality.cpp

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

� Copyright  1995 - 2013 Fraunhofer-Gesellschaft zur F�rderung der angewandten Forschung e.V.
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 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,
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2.    COPYRIGHT LICENSE

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5.    CONTACT INFORMATION

Fraunhofer Institute for Integrated Circuits IIS
Attention: Audio and Multimedia Departments - FDK AAC LL
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----------------------------------------------------------------------------------------------------------- */

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

   author:   M. Werner
   contents/description: Convert chaos measure to the tonality index

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

#include "tonality.h"
#include "chaosmeasure.h"

static const FIXP_DBL normlog = (FIXP_DBL)0xd977d949; /*FL2FXCONST_DBL(-0.4342944819f * FDKlog(2.0)/FDKlog(2.7182818)); */

static void FDKaacEnc_CalcSfbTonality(FIXP_DBL      *RESTRICT spectrum,
							INT           *RESTRICT sfbMaxScaleSpec,
                            FIXP_DBL      *RESTRICT chaosMeasure,
                            FIXP_SGL      *RESTRICT sfbTonality,
                            INT           sfbCnt,
                            const INT     *RESTRICT sfbOffset,
                            FIXP_DBL      *RESTRICT sfbEnergyLD64 );


void FDKaacEnc_CalculateFullTonality(FIXP_DBL      *RESTRICT spectrum,
						             INT           *RESTRICT sfbMaxScaleSpec,
                                     FIXP_DBL      *RESTRICT sfbEnergyLD64,
                                     FIXP_SGL      *RESTRICT sfbTonality,
                                     INT            sfbCnt,
                                     const INT     *sfbOffset,
                                     INT            usePns)
{
  INT j;
#if defined(ARCH_PREFER_MULT_32x16)
  FIXP_SGL alpha_0 = FL2FXCONST_SGL(0.25f);       /* used in smooth ChaosMeasure */
  FIXP_SGL alpha_1 = FL2FXCONST_SGL(1.0f-0.25f);  /* used in smooth ChaosMeasure */
#else
  FIXP_DBL alpha_0 = FL2FXCONST_DBL(0.25f);       /* used in smooth ChaosMeasure */
  FIXP_DBL alpha_1 = FL2FXCONST_DBL(1.0f-0.25f);  /* used in smooth ChaosMeasure */
#endif
  INT numberOfLines = sfbOffset[sfbCnt];

  if (!usePns)
    return;

  C_ALLOC_SCRATCH_START(chaosMeasurePerLine, FIXP_DBL, (1024));
  /* calculate chaos measure */
  FDKaacEnc_CalculateChaosMeasure(spectrum,
                        numberOfLines,
                        chaosMeasurePerLine);

  /* smooth ChaosMeasure */
  for (j=1;j<numberOfLines;j++) {
    FIXP_DBL tmp = fMultDiv2(alpha_1, chaosMeasurePerLine[j]);
    chaosMeasurePerLine[j] = fMultAdd(tmp, alpha_0, chaosMeasurePerLine[j-1]);
  }

  FDKaacEnc_CalcSfbTonality(spectrum,
                  sfbMaxScaleSpec,
                  chaosMeasurePerLine,
                  sfbTonality,
                  sfbCnt,
                  sfbOffset,
                  sfbEnergyLD64);

  C_ALLOC_SCRATCH_END(chaosMeasurePerLine, FIXP_DBL, (1024));
}


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

    functionname: CalculateTonalityIndex
    description:  computes tonality values out of unpredictability values
                  limits range and computes log()
    returns:
    input:        ptr to energies, ptr to chaos measure values,
                  number of sfb
    output:       sfb wise tonality values

*****************************************************************************/
static void FDKaacEnc_CalcSfbTonality(FIXP_DBL      *RESTRICT spectrum,
                            INT           *RESTRICT sfbMaxScaleSpec,
                            FIXP_DBL      *RESTRICT chaosMeasure,
                            FIXP_SGL      *RESTRICT sfbTonality,
                            INT           sfbCnt,
                            const INT     *RESTRICT sfbOffset,
                            FIXP_DBL      *RESTRICT sfbEnergyLD64 )
{
    INT i, j;

    for (i=0; i<sfbCnt; i++) {
      FIXP_DBL chaosMeasureSfbLD64;
      INT shiftBits = fixMax(0,sfbMaxScaleSpec[i] - 4);  /* max sfbWidth = 96 ; 2^7=128 => 7/2 = 4 (spc*spc) */

      FIXP_DBL chaosMeasureSfb = FL2FXCONST_DBL(0.0);

      /* calc chaosMeasurePerSfb */
      for (j=(sfbOffset[i+1]-sfbOffset[i])-1; j>=0; j--) {
        FIXP_DBL tmp = (*spectrum++)<<shiftBits;
        FIXP_DBL lineNrg = fMultDiv2(tmp, tmp);
        chaosMeasureSfb = fMultAddDiv2(chaosMeasureSfb, lineNrg, *chaosMeasure++);
      }

      /* calc tonalityPerSfb */
      if (chaosMeasureSfb != FL2FXCONST_DBL(0.0))
      {
        /* add ld(convtone)/64 and 2/64 bec.fMultDiv2 */
        chaosMeasureSfbLD64 = CalcLdData((chaosMeasureSfb)) - sfbEnergyLD64[i];
        chaosMeasureSfbLD64 += FL2FXCONST_DBL(3.0f/64) - ((FIXP_DBL)(shiftBits)<<(DFRACT_BITS-6));

        if (chaosMeasureSfbLD64 > FL2FXCONST_DBL(-0.0519051) )     /* > ld(0.05)+ld(2) */
        {
          if (chaosMeasureSfbLD64 <= FL2FXCONST_DBL(0.0) )
		    sfbTonality[i] = FX_DBL2FX_SGL(fMultDiv2( chaosMeasureSfbLD64 , normlog ) << 7);
          else
            sfbTonality[i] = FL2FXCONST_SGL(0.0);
        }
        else
          sfbTonality[i] = (FIXP_SGL)MAXVAL_SGL;
      }
      else
        sfbTonality[i] = (FIXP_SGL)MAXVAL_SGL;
    }
}