Fraunhofer AAC codec.

License boilerplate update to follow.

Change-Id: I2810460c11a58b6d148d84673cc031f3685e79b5

1 files changed, 297 insertions, 0 deletions

diff --git a/libAACenc/src/band_nrg.cpp b/libAACenc/src/band_nrg.cpp
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+/*****************************  MPEG-4 AAC 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.
+
+
+   $Id$
+   Initial author:       M. Werner
+   contents/description: Band/Line energy calculations
+
+   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.
+
+******************************************************************************/
+
+#include "band_nrg.h"
+
+
+/*****************************************************************************
+  functionname: FDKaacEnc_CalcSfbMaxScaleSpec
+  description:
+  input:
+  output:
+*****************************************************************************/
+void
+FDKaacEnc_CalcSfbMaxScaleSpec(const FIXP_DBL *RESTRICT mdctSpectrum,
+                              const INT      *RESTRICT bandOffset,
+                              INT            *RESTRICT sfbMaxScaleSpec,
+                              const INT       numBands)
+{
+  INT i,j;
+  FIXP_DBL maxSpc, tmp;
+
+  for(i=0; i<numBands; i++) {
+    maxSpc = (FIXP_DBL)0;
+    for (j=bandOffset[i]; j<bandOffset[i+1]; j++) {
+      tmp = fixp_abs(mdctSpectrum[j]);
+      maxSpc = fixMax(maxSpc, tmp);
+    }
+    sfbMaxScaleSpec[i] = (maxSpc==(FIXP_DBL)0) ? (DFRACT_BITS-2) : CntLeadingZeros(maxSpc)-1;
+    /* CountLeadingBits() is not necessary here since test value is always > 0 */
+  }
+}
+
+/*****************************************************************************
+  functionname: FDKaacEnc_CheckBandEnergyOptim
+  description:
+  input:
+  output:
+*****************************************************************************/
+FIXP_DBL
+FDKaacEnc_CheckBandEnergyOptim(const FIXP_DBL *RESTRICT mdctSpectrum,
+                               INT            *RESTRICT sfbMaxScaleSpec,
+                               const INT      *RESTRICT bandOffset,
+                               const INT       numBands,
+                               FIXP_DBL       *RESTRICT bandEnergy,
+                               FIXP_DBL       *RESTRICT bandEnergyLdData,
+                               INT             minSpecShift)
+{
+  INT i, j, scale, nr = 0;
+  FIXP_DBL maxNrgLd = FL2FXCONST_DBL(-1.0f);
+  FIXP_DBL maxNrg = 0;
+  FIXP_DBL spec;
+
+  for(i=0; i<numBands; i++) {
+    scale = fixMax(0, sfbMaxScaleSpec[i]-4);
+    FIXP_DBL tmp = 0;
+    for (j=bandOffset[i]; j<bandOffset[i+1]; j++){
+       spec = mdctSpectrum[j]<<scale;
+       tmp = fPow2AddDiv2(tmp, spec);
+    }
+    bandEnergy[i] = tmp<<1;
+
+    /* calculate ld of bandNrg, subtract scaling */
+    bandEnergyLdData[i] = CalcLdData(bandEnergy[i]);
+    if (bandEnergyLdData[i] != FL2FXCONST_DBL(-1.0f)) {
+      bandEnergyLdData[i] -= scale*FL2FXCONST_DBL(2.0/64);
+    }
+    /* find index of maxNrg */
+    if (bandEnergyLdData[i] > maxNrgLd) {
+        maxNrgLd = bandEnergyLdData[i];
+        nr = i;
+    }
+  }
+
+  /* return unscaled maxNrg*/
+  scale = fixMax(0,sfbMaxScaleSpec[nr]-4);
+  scale = fixMax(2*(minSpecShift-scale),-(DFRACT_BITS-1));
+
+  maxNrg = scaleValue(bandEnergy[nr], scale);
+
+  return maxNrg;
+}
+
+/*****************************************************************************
+  functionname: FDKaacEnc_CalcBandEnergyOptimLong
+  description:
+  input:
+  output:
+*****************************************************************************/
+INT
+FDKaacEnc_CalcBandEnergyOptimLong(const FIXP_DBL *RESTRICT mdctSpectrum,
+                                  INT            *RESTRICT sfbMaxScaleSpec,
+                                  const INT      *RESTRICT bandOffset,
+                                  const INT       numBands,
+                                  FIXP_DBL       *RESTRICT bandEnergy,
+                                  FIXP_DBL       *RESTRICT bandEnergyLdData)
+{
+  INT i, j, shiftBits = 0;
+  FIXP_DBL maxNrgLd = FL2FXCONST_DBL(0.0f);
+
+  FIXP_DBL spec;
+
+  for(i=0; i<numBands; i++) {
+     INT leadingBits = sfbMaxScaleSpec[i]-4;            /* max sfbWidth = 96 ; 2^7=128 => 7/2 = 4 (spc*spc) */
+     FIXP_DBL tmp = FL2FXCONST_DBL(0.0);
+     /* don't use scaleValue() here, it increases workload quite sufficiently... */
+     if (leadingBits>=0) {
+        for (j=bandOffset[i];j<bandOffset[i+1];j++) {
+           spec = mdctSpectrum[j]<<leadingBits;
+           tmp = fPow2AddDiv2(tmp, spec);
+        }
+     } else {
+        INT shift = -leadingBits;
+        for (j=bandOffset[i];j<bandOffset[i+1];j++){
+           spec = mdctSpectrum[j]>>shift;
+           tmp = fPow2AddDiv2(tmp, spec);
+        }
+     }
+     bandEnergy[i] = tmp<<1;
+  }
+
+  /* calculate ld of bandNrg, subtract scaling */
+  LdDataVector(bandEnergy, bandEnergyLdData, numBands);
+  for(i=numBands; i--!=0; ) {
+      FIXP_DBL scaleDiff = (sfbMaxScaleSpec[i]-4)*FL2FXCONST_DBL(2.0/64);
+
+      bandEnergyLdData[i] = (bandEnergyLdData[i] >= ((FL2FXCONST_DBL(-1.f)>>1) + (scaleDiff>>1)))
+                          ? bandEnergyLdData[i]-scaleDiff : FL2FXCONST_DBL(-1.f);
+      /* find maxNrgLd */
+      maxNrgLd = fixMax(maxNrgLd, bandEnergyLdData[i]);
+  }
+
+  if (maxNrgLd<=(FIXP_DBL)0)
+  {
+     for(i=numBands; i--!=0; )
+     {
+         INT scale = fixMin((sfbMaxScaleSpec[i]-4)<<1,(DFRACT_BITS-1));
+         bandEnergy[i] = scaleValue(bandEnergy[i], -scale);
+     }
+     return 0;
+  }
+  else
+  {  /* scale down NRGs */
+     while (maxNrgLd>FL2FXCONST_DBL(0.0f))
+     {
+        maxNrgLd -=  FL2FXCONST_DBL(2.0/64);
+        shiftBits++;
+     }
+     for(i=numBands; i--!=0; )
+     {
+         INT scale = fixMin( ((sfbMaxScaleSpec[i]-4)+shiftBits)<<1, (DFRACT_BITS-1));
+         bandEnergyLdData[i] -= shiftBits*FL2FXCONST_DBL(2.0/64);
+         bandEnergy[i] = scaleValue(bandEnergy[i], -scale);
+     }
+     return shiftBits;
+  }
+}
+
+
+/*****************************************************************************
+  functionname: FDKaacEnc_CalcBandEnergyOptimShort
+  description:
+  input:
+  output:
+*****************************************************************************/
+void
+FDKaacEnc_CalcBandEnergyOptimShort(const FIXP_DBL *RESTRICT mdctSpectrum,
+                                   INT            *RESTRICT sfbMaxScaleSpec,
+                                   const INT      *RESTRICT bandOffset,
+                                   const INT       numBands,
+                                   FIXP_DBL       *RESTRICT bandEnergy)
+{
+  INT i, j;
+
+  for(i=0; i<numBands; i++)
+  {
+    int leadingBits = fixMax(0,sfbMaxScaleSpec[i]-4);            /* max sfbWidth = 96 ; 2^7=128 => 7/2 = 4 (spc*spc) */
+    FIXP_DBL tmp = FL2FXCONST_DBL(0.0);
+    for (j=bandOffset[i];j<bandOffset[i+1];j++)
+    {
+       FIXP_DBL spec = mdctSpectrum[j]<<leadingBits;
+       tmp = fPow2AddDiv2(tmp, spec);
+    }
+    bandEnergy[i] = tmp<<1;
+  }
+
+  for(i=0; i<numBands; i++)
+  {
+      INT scale = 2*fixMax(0,sfbMaxScaleSpec[i]-4);            /* max sfbWidth = 96 ; 2^7=128 => 7/2 = 4 (spc*spc) */
+      scale = fixMin(scale,(DFRACT_BITS-1));
+      bandEnergy[i] >>= scale;
+  }
+}
+
+
+/*****************************************************************************
+  functionname: FDKaacEnc_CalcBandNrgMSOpt
+  description:
+  input:
+  output:
+*****************************************************************************/
+void FDKaacEnc_CalcBandNrgMSOpt(const FIXP_DBL   *RESTRICT mdctSpectrumLeft,
+                                const FIXP_DBL   *RESTRICT mdctSpectrumRight,
+                                INT              *RESTRICT sfbMaxScaleSpecLeft,
+                                INT              *RESTRICT sfbMaxScaleSpecRight,
+                                const INT        *RESTRICT bandOffset,
+                                const INT         numBands,
+                                FIXP_DBL         *RESTRICT bandEnergyMid,
+                                FIXP_DBL         *RESTRICT bandEnergySide,
+                                INT               calcLdData,
+                                FIXP_DBL         *RESTRICT bandEnergyMidLdData,
+                                FIXP_DBL         *RESTRICT bandEnergySideLdData)
+{
+  INT i, j, minScale;
+  FIXP_DBL NrgMid, NrgSide, specm, specs;
+
+  for (i=0; i<numBands; i++) {
+
+    NrgMid = NrgSide = FL2FXCONST_DBL(0.0);
+    minScale = fixMin(sfbMaxScaleSpecLeft[i], sfbMaxScaleSpecRight[i])-4;
+    minScale = fixMax(0, minScale);
+
+    if (minScale > 0) {
+      for (j=bandOffset[i];j<bandOffset[i+1];j++) {
+          FIXP_DBL specL = mdctSpectrumLeft[j]<<(minScale-1);
+          FIXP_DBL specR = mdctSpectrumRight[j]<<(minScale-1);
+          specm = specL + specR;
+          specs = specL - specR;
+          NrgMid = fPow2AddDiv2(NrgMid, specm);
+          NrgSide = fPow2AddDiv2(NrgSide, specs);
+      }
+    } else {
+      for (j=bandOffset[i];j<bandOffset[i+1];j++) {
+          FIXP_DBL specL = mdctSpectrumLeft[j]>>1;
+          FIXP_DBL specR = mdctSpectrumRight[j]>>1;
+          specm = specL + specR;
+          specs = specL - specR;
+          NrgMid = fPow2AddDiv2(NrgMid, specm);
+          NrgSide = fPow2AddDiv2(NrgSide, specs);
+      }
+    }
+    bandEnergyMid[i] = NrgMid<<1;
+    bandEnergySide[i] = NrgSide<<1;
+  }
+
+  if(calcLdData) {
+    LdDataVector(bandEnergyMid, bandEnergyMidLdData, numBands);
+    LdDataVector(bandEnergySide, bandEnergySideLdData, numBands);
+  }
+
+  for (i=0; i<numBands; i++)
+  {
+    INT minScale = fixMin(sfbMaxScaleSpecLeft[i], sfbMaxScaleSpecRight[i]);
+    INT scale = fixMax(0, 2*(minScale-4));
+
+    if (calcLdData)
+    {
+       /* using the minimal scaling of left and right channel can cause very small energies;
+       check ldNrg before subtract scaling multiplication: fract*INT we don't need fMult */
+       
+       int minus = scale*FL2FXCONST_DBL(1.0/64);
+
+       if (bandEnergyMidLdData[i] != FL2FXCONST_DBL(-1.0f))
+         bandEnergyMidLdData[i] -= minus;
+
+       if (bandEnergySideLdData[i] != FL2FXCONST_DBL(-1.0f))
+         bandEnergySideLdData[i] -= minus;
+    }
+    scale = fixMin(scale, (DFRACT_BITS-1));
+    bandEnergyMid[i]  >>= scale;
+    bandEnergySide[i] >>= scale;
+  }
+}