aboutsummaryrefslogtreecommitdiffstats
path: root/libAACenc/src/quantize.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'libAACenc/src/quantize.cpp')
-rw-r--r--libAACenc/src/quantize.cpp323
1 files changed, 323 insertions, 0 deletions
diff --git a/libAACenc/src/quantize.cpp b/libAACenc/src/quantize.cpp
new file mode 100644
index 0000000..b8eb5de
--- /dev/null
+++ b/libAACenc/src/quantize.cpp
@@ -0,0 +1,323 @@
+/******************************** 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);
+}
+
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-27 11:39:03 +0000