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

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

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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.

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Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality,
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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 **************************

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;
    }
}

C++程序 | 205行 | 9.23 KB

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