Fraunhofer AAC codec.

License boilerplate update to follow.

Change-Id: I2810460c11a58b6d148d84673cc031f3685e79b5

1 files changed, 323 insertions, 0 deletions

diff --git a/libAACenc/src/quantize.cpp b/libAACenc/src/quantize.cpp
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+/******************************** MPEG Audio Encoder **************************
+
+                     (C) Copyright Fraunhofer IIS (1999)
+                               All Rights Reserved
+
+    Please be advised that this software and/or program delivery is
+    Confidential Information of Fraunhofer and subject to and covered by the
+
+    Fraunhofer IIS Software Evaluation Agreement
+    between Google Inc. and  Fraunhofer
+    effective and in full force since March 1, 2012.
+
+    You may use this software and/or program only under the terms and
+    conditions described in the above mentioned Fraunhofer IIS Software
+    Evaluation Agreement. Any other and/or further use requires a separate agreement.
+
+
+   This software and/or program is protected by copyright law and international
+   treaties. Any reproduction or distribution of this software and/or program,
+   or any portion of it, may result in severe civil and criminal penalties, and
+   will be prosecuted to the maximum extent possible under law.
+
+   $Id$
+   Initial author:       M.Werner
+   contents/description: Quantization
+
+******************************************************************************/
+
+#include "quantize.h"
+
+#include "aacEnc_rom.h"
+
+/*****************************************************************************
+
+    functionname: FDKaacEnc_quantizeLines
+    description: quantizes spectrum lines
+    returns:
+    input: global gain, number of lines to process, spectral data
+    output: quantized spectrum
+
+*****************************************************************************/
+static void FDKaacEnc_quantizeLines(INT      gain,
+                          INT      noOfLines,
+                          FIXP_DBL *mdctSpectrum,
+                          SHORT      *quaSpectrum)
+{
+  int   line;
+  FIXP_DBL k = FL2FXCONST_DBL(-0.0946f + 0.5f)>>16;
+  FIXP_QTD quantizer = FDKaacEnc_quantTableQ[(-gain)&3];
+  INT      quantizershift = ((-gain)>>2)+1;
+
+
+  for (line = 0; line < noOfLines; line++)
+  {
+    FIXP_DBL accu = fMultDiv2(mdctSpectrum[line],quantizer);
+
+    if (accu < FL2FXCONST_DBL(0.0f))
+    {
+      accu=-accu;
+      /* normalize */
+      INT   accuShift = CntLeadingZeros(accu) - 1;  /* CountLeadingBits() is not necessary here since test value is always > 0 */
+      accu <<= accuShift;
+      INT tabIndex = (INT)(accu>>(DFRACT_BITS-2-MANT_DIGITS))&(~MANT_SIZE);
+      INT totalShift = quantizershift-accuShift+1;
+      accu = fMultDiv2(FDKaacEnc_mTab_3_4[tabIndex],FDKaacEnc_quantTableE[totalShift&3]);
+      totalShift = (16-4)-(3*(totalShift>>2));
+      FDK_ASSERT(totalShift >=0); /* MAX_QUANT_VIOLATION */
+      accu>>=totalShift;
+      quaSpectrum[line] = (SHORT)(-((LONG)(k + accu) >> (DFRACT_BITS-1-16)));
+    }
+    else if(accu > FL2FXCONST_DBL(0.0f))
+    {
+      /* normalize */
+      INT   accuShift = CntLeadingZeros(accu) - 1;  /* CountLeadingBits() is not necessary here since test value is always > 0 */
+      accu <<= accuShift;
+      INT tabIndex = (INT)(accu>>(DFRACT_BITS-2-MANT_DIGITS))&(~MANT_SIZE);
+      INT totalShift = quantizershift-accuShift+1;
+      accu = fMultDiv2(FDKaacEnc_mTab_3_4[tabIndex],FDKaacEnc_quantTableE[totalShift&3]);
+      totalShift = (16-4)-(3*(totalShift>>2));
+      FDK_ASSERT(totalShift >=0); /* MAX_QUANT_VIOLATION */
+      accu>>=totalShift;
+      quaSpectrum[line] = (SHORT)((LONG)(k + accu) >> (DFRACT_BITS-1-16));
+    }
+    else
+      quaSpectrum[line]=0;
+  }
+}
+
+
+/*****************************************************************************
+
+    functionname:iFDKaacEnc_quantizeLines
+    description: iquantizes spectrum lines
+                 mdctSpectrum = iquaSpectrum^4/3 *2^(0.25*gain)
+    input: global gain, number of lines to process,quantized spectrum
+    output: spectral data
+
+*****************************************************************************/
+static void FDKaacEnc_invQuantizeLines(INT  gain,
+                             INT  noOfLines,
+                             SHORT *quantSpectrum,
+                             FIXP_DBL *mdctSpectrum)
+
+{
+  INT iquantizermod;
+  INT iquantizershift;
+  INT line;
+
+  iquantizermod = gain&3;
+  iquantizershift = gain>>2;
+
+  for (line = 0; line < noOfLines; line++) {
+
+    if(quantSpectrum[line] < 0) {
+      FIXP_DBL accu;
+      INT ex,specExp,tabIndex;
+      FIXP_DBL s,t;
+
+      accu = (FIXP_DBL) -quantSpectrum[line];
+
+      ex = CountLeadingBits(accu);
+      accu <<= ex;
+      specExp = (DFRACT_BITS-1) - ex;
+
+      FDK_ASSERT(specExp < 14);       /* this fails if abs(value) > 8191 */
+
+      tabIndex = (INT)(accu>>(DFRACT_BITS-2-MANT_DIGITS))&(~MANT_SIZE);
+
+      /* calculate "mantissa" ^4/3 */
+      s = FDKaacEnc_mTab_4_3Elc[tabIndex];
+
+      /* get approperiate exponent multiplier for specExp^3/4 combined with scfMod */
+      t = FDKaacEnc_specExpMantTableCombElc[iquantizermod][specExp];
+
+      /* multiply "mantissa" ^4/3 with exponent multiplier */
+      accu = fMult(s,t);
+
+      /* get approperiate exponent shifter */
+      specExp = FDKaacEnc_specExpTableComb[iquantizermod][specExp]-1; /* -1 to avoid overflows in accu */
+
+      if ((-iquantizershift-specExp) < 0)
+        accu <<= -(-iquantizershift-specExp);
+      else
+        accu >>= -iquantizershift-specExp;
+
+      mdctSpectrum[line] = -accu;
+    }
+    else if (quantSpectrum[line] > 0) {
+      FIXP_DBL accu;
+      INT ex,specExp,tabIndex;
+      FIXP_DBL s,t;
+
+      accu = (FIXP_DBL)(INT)quantSpectrum[line];
+
+      ex = CountLeadingBits(accu);
+      accu <<= ex;
+      specExp = (DFRACT_BITS-1) - ex;
+
+      FDK_ASSERT(specExp < 14);       /* this fails if abs(value) > 8191 */
+
+      tabIndex = (INT)(accu>>(DFRACT_BITS-2-MANT_DIGITS))&(~MANT_SIZE);
+
+      /* calculate "mantissa" ^4/3 */
+      s = FDKaacEnc_mTab_4_3Elc[tabIndex];
+
+      /* get approperiate exponent multiplier for specExp^3/4 combined with scfMod */
+      t = FDKaacEnc_specExpMantTableCombElc[iquantizermod][specExp];
+
+      /* multiply "mantissa" ^4/3 with exponent multiplier */
+      accu = fMult(s,t);
+
+      /* get approperiate exponent shifter */
+      specExp = FDKaacEnc_specExpTableComb[iquantizermod][specExp]-1; /* -1 to avoid overflows in accu */
+
+      if (( -iquantizershift-specExp) < 0)
+        accu <<= -(-iquantizershift-specExp);
+      else
+        accu >>= -iquantizershift-specExp;
+
+      mdctSpectrum[line] = accu;
+    }
+    else {
+      mdctSpectrum[line] = FL2FXCONST_DBL(0.0f);
+    }
+  }
+}
+
+/*****************************************************************************
+
+    functionname: FDKaacEnc_QuantizeSpectrum
+    description: quantizes the entire spectrum
+    returns:
+    input: number of scalefactor bands to be quantized, ...
+    output: quantized spectrum
+
+*****************************************************************************/
+void FDKaacEnc_QuantizeSpectrum(INT sfbCnt,
+                      INT maxSfbPerGroup,
+                      INT sfbPerGroup,
+                      INT *sfbOffset,
+                      FIXP_DBL *mdctSpectrum,
+                      INT globalGain,
+                      INT *scalefactors,
+                      SHORT *quantizedSpectrum)
+{
+  INT sfbOffs,sfb;
+
+  /* in FDKaacEnc_quantizeLines quaSpectrum is calculated with:
+        spec^(3/4) * 2^(-3/16*QSS) * 2^(3/4*scale) + k
+     simplify scaling calculation and reduce QSS before:
+        spec^(3/4) * 2^(-3/16*(QSS - 4*scale)) */
+
+  for(sfbOffs=0;sfbOffs<sfbCnt;sfbOffs+=sfbPerGroup)
+  for (sfb = 0; sfb < maxSfbPerGroup; sfb++)
+  {
+    INT scalefactor = scalefactors[sfbOffs+sfb] ;
+
+    FDKaacEnc_quantizeLines(globalGain - scalefactor, /* QSS */
+                  sfbOffset[sfbOffs+sfb+1] - sfbOffset[sfbOffs+sfb],
+                  mdctSpectrum + sfbOffset[sfbOffs+sfb],
+                  quantizedSpectrum + sfbOffset[sfbOffs+sfb]);
+  }
+}
+
+/*****************************************************************************
+
+    functionname: FDKaacEnc_calcSfbDist
+    description: calculates distortion of quantized values
+    returns: distortion
+    input: gain, number of lines to process, spectral data
+    output:
+
+*****************************************************************************/
+FIXP_DBL FDKaacEnc_calcSfbDist(FIXP_DBL *mdctSpectrum,
+                     SHORT *quantSpectrum,
+                     INT noOfLines,
+                     INT gain
+                     )
+{
+  INT i,scale;
+  FIXP_DBL xfsf;
+  FIXP_DBL diff;
+  FIXP_DBL invQuantSpec;
+
+  xfsf = FL2FXCONST_DBL(0.0f);
+
+  for (i=0; i<noOfLines; i++) {
+    /* quantization */
+    FDKaacEnc_quantizeLines(gain,
+                  1,
+                 &mdctSpectrum[i],
+                 &quantSpectrum[i]);
+
+    /* inverse quantization */
+    FDKaacEnc_invQuantizeLines(gain,1,&quantSpectrum[i],&invQuantSpec);
+
+    /* dist */
+    diff = fixp_abs(fixp_abs(invQuantSpec) - fixp_abs(mdctSpectrum[i]>>1));
+
+    scale = CountLeadingBits(diff);
+    diff = scaleValue(diff, scale);
+    diff = fPow2(diff);
+    scale = fixMin(2*(scale-1), DFRACT_BITS-1);
+
+    diff = scaleValue(diff, -scale);
+
+    xfsf = xfsf + diff;
+  }
+
+  xfsf = CalcLdData(xfsf);
+
+  return xfsf;
+}
+
+/*****************************************************************************
+
+    functionname: FDKaacEnc_calcSfbQuantEnergyAndDist
+    description: calculates energy and distortion of quantized values
+    returns:
+    input: gain, number of lines to process, quantized spectral data,
+           spectral data
+    output: energy, distortion
+
+*****************************************************************************/
+void FDKaacEnc_calcSfbQuantEnergyAndDist(FIXP_DBL *mdctSpectrum,
+                               SHORT *quantSpectrum,
+                               INT noOfLines,
+                               INT gain,
+                               FIXP_DBL *en,
+                               FIXP_DBL *dist)
+{
+  INT i,scale;
+  FIXP_DBL invQuantSpec;
+  FIXP_DBL diff;
+
+  *en   = FL2FXCONST_DBL(0.0f);
+  *dist = FL2FXCONST_DBL(0.0f);
+
+  for (i=0; i<noOfLines; i++) {
+    /* inverse quantization */
+    FDKaacEnc_invQuantizeLines(gain,1,&quantSpectrum[i],&invQuantSpec);
+
+    /* energy */
+    *en += fPow2(invQuantSpec);
+
+    /* dist */
+    diff = fixp_abs(fixp_abs(invQuantSpec) - fixp_abs(mdctSpectrum[i]>>1));
+
+    scale = CountLeadingBits(diff);
+    diff = scaleValue(diff, scale);
+    diff = fPow2(diff);
+
+    scale = fixMin(2*(scale-1), DFRACT_BITS-1);
+
+    diff = scaleValue(diff, -scale);
+
+    *dist += diff;
+  }
+
+  *en   = CalcLdData(*en)+FL2FXCONST_DBL(0.03125f);
+  *dist = CalcLdData(*dist);
+}
+