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authorDave Burke <daveburke@google.com>2012-04-17 09:51:45 -0700
committerDave Burke <daveburke@google.com>2012-04-17 23:04:43 -0700
commit9bf37cc9712506b2483650c82d3c41152337ef7e (patch)
tree77db44e2bae06e3d144b255628be2b7a55c581d3 /libAACenc/src/line_pe.cpp
parenta37315fe10ee143d6d0b28c19d41a476a23e63ea (diff)
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Fraunhofer AAC codec.
License boilerplate update to follow. Change-Id: I2810460c11a58b6d148d84673cc031f3685e79b5
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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: Perceptual entropie module
+
+******************************************************************************/
+
+#include "line_pe.h"
+#include "sf_estim.h"
+#include "bit_cnt.h"
+
+#include "genericStds.h"
+
+static const FIXP_DBL C1LdData = FL2FXCONST_DBL(3.0/LD_DATA_SCALING); /* C1 = 3.0 = log(8.0)/log(2) */
+static const FIXP_DBL C2LdData = FL2FXCONST_DBL(1.3219281/LD_DATA_SCALING); /* C2 = 1.3219281 = log(2.5)/log(2) */
+static const FIXP_DBL C3LdData = FL2FXCONST_DBL(0.5593573); /* 1-C2/C1 */
+
+
+/* constants that do not change during successive pe calculations */
+void FDKaacEnc_prepareSfbPe(PE_CHANNEL_DATA *peChanData,
+ const FIXP_DBL *sfbEnergyLdData,
+ const FIXP_DBL *sfbThresholdLdData,
+ const FIXP_DBL *sfbFormFactorLdData,
+ const INT *sfbOffset,
+ const INT sfbCnt,
+ const INT sfbPerGroup,
+ const INT maxSfbPerGroup)
+{
+ INT sfbGrp,sfb;
+ INT sfbWidth;
+ FIXP_DBL avgFormFactorLdData;
+ const FIXP_DBL formFacScaling = FL2FXCONST_DBL((float)FORM_FAC_SHIFT/LD_DATA_SCALING);
+
+ for (sfbGrp = 0;sfbGrp < sfbCnt;sfbGrp+=sfbPerGroup) {
+ for (sfb=0; sfb<maxSfbPerGroup; sfb++) {
+ if ((FIXP_DBL)sfbEnergyLdData[sfbGrp+sfb] > (FIXP_DBL)sfbThresholdLdData[sfbGrp+sfb]) {
+ sfbWidth = sfbOffset[sfbGrp+sfb+1] - sfbOffset[sfbGrp+sfb];
+ /* estimate number of active lines */
+ avgFormFactorLdData = ((-sfbEnergyLdData[sfbGrp+sfb]>>1) + (CalcLdInt(sfbWidth)>>1))>>1;
+ peChanData->sfbNLines[sfbGrp+sfb] =
+ (INT)CalcInvLdData( (sfbFormFactorLdData[sfbGrp+sfb] + formFacScaling) + avgFormFactorLdData);
+ }
+ else {
+ peChanData->sfbNLines[sfbGrp+sfb] = 0;
+ }
+ }
+ }
+}
+
+/*
+ formula for one sfb:
+ pe = n * ld(en/thr), if ld(en/thr) >= C1
+ pe = n * (C2 + C3 * ld(en/thr)), if ld(en/thr) < C1
+ n: estimated number of lines in sfb,
+ ld(x) = log(x)/log(2)
+
+ constPart is sfbPe without the threshold part n*ld(thr) or n*C3*ld(thr)
+*/
+void FDKaacEnc_calcSfbPe(PE_CHANNEL_DATA *RESTRICT peChanData,
+ const FIXP_DBL *RESTRICT sfbEnergyLdData,
+ const FIXP_DBL *RESTRICT sfbThresholdLdData,
+ const INT sfbCnt,
+ const INT sfbPerGroup,
+ const INT maxSfbPerGroup,
+ const INT *isBook,
+ const INT *isScale)
+{
+ INT sfbGrp,sfb;
+ INT nLines;
+ FIXP_DBL logDataRatio;
+ INT lastValIs = 0;
+
+ peChanData->pe = 0;
+ peChanData->constPart = 0;
+ peChanData->nActiveLines = 0;
+
+ for(sfbGrp = 0;sfbGrp < sfbCnt;sfbGrp+=sfbPerGroup){
+ for (sfb=0; sfb<maxSfbPerGroup; sfb++) {
+ if ((FIXP_DBL)sfbEnergyLdData[sfbGrp+sfb] > (FIXP_DBL)sfbThresholdLdData[sfbGrp+sfb]) {
+ logDataRatio = (FIXP_DBL)(sfbEnergyLdData[sfbGrp+sfb] - sfbThresholdLdData[sfbGrp+sfb]);
+ nLines = peChanData->sfbNLines[sfbGrp+sfb];
+ if (logDataRatio >= C1LdData) {
+ /* scale sfbPe and sfbConstPart with PE_CONSTPART_SHIFT */
+ peChanData->sfbPe[sfbGrp+sfb] = fMultDiv2(logDataRatio, (FIXP_DBL)(nLines<<(LD_DATA_SHIFT+PE_CONSTPART_SHIFT+1)));
+ peChanData->sfbConstPart[sfbGrp+sfb] =
+ fMultDiv2(sfbEnergyLdData[sfbGrp+sfb], (FIXP_DBL)(nLines<<(LD_DATA_SHIFT+PE_CONSTPART_SHIFT+1))); ;
+
+ }
+ else {
+ /* scale sfbPe and sfbConstPart with PE_CONSTPART_SHIFT */
+ peChanData->sfbPe[sfbGrp+sfb] =
+ fMultDiv2(((FIXP_DBL)C2LdData + fMult(C3LdData,logDataRatio)), (FIXP_DBL)(nLines<<(LD_DATA_SHIFT+PE_CONSTPART_SHIFT+1)));
+
+ peChanData->sfbConstPart[sfbGrp+sfb] =
+ fMultDiv2(((FIXP_DBL)C2LdData + fMult(C3LdData,sfbEnergyLdData[sfbGrp+sfb])),
+ (FIXP_DBL)(nLines<<(LD_DATA_SHIFT+PE_CONSTPART_SHIFT+1))) ;
+
+ nLines = fMultI(C3LdData, nLines);
+ }
+ peChanData->sfbNActiveLines[sfbGrp+sfb] = nLines;
+ }
+ else if( isBook[sfb] ) {
+ /* provide for cost of scale factor for Intensity */
+ INT delta = isScale[sfbGrp+sfb] - lastValIs;
+ lastValIs = isScale[sfbGrp+sfb];
+ peChanData->sfbPe[sfbGrp+sfb] = FDKaacEnc_bitCountScalefactorDelta(delta)<<PE_CONSTPART_SHIFT;
+ peChanData->sfbConstPart[sfbGrp+sfb] = 0;
+ peChanData->sfbNActiveLines[sfbGrp+sfb] = 0;
+ }
+ else {
+ peChanData->sfbPe[sfbGrp+sfb] = 0;
+ peChanData->sfbConstPart[sfbGrp+sfb] = 0;
+ peChanData->sfbNActiveLines[sfbGrp+sfb] = 0;
+ }
+ /* sum up peChanData values */
+ peChanData->pe += peChanData->sfbPe[sfbGrp+sfb];
+ peChanData->constPart += peChanData->sfbConstPart[sfbGrp+sfb];
+ peChanData->nActiveLines += peChanData->sfbNActiveLines[sfbGrp+sfb];
+ }
+ }
+ /* correct scaled pe and constPart values */
+ peChanData->pe>>=PE_CONSTPART_SHIFT;
+ peChanData->constPart>>=PE_CONSTPART_SHIFT;
+}