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Diffstat (limited to 'libAACenc/src/line_pe.cpp')
| -rw-r--r-- | libAACenc/src/line_pe.cpp | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/libAACenc/src/line_pe.cpp b/libAACenc/src/line_pe.cpp new file mode 100644 index 0000000..cf43a81 --- /dev/null +++ b/libAACenc/src/line_pe.cpp @@ -0,0 +1,145 @@ +/******************************** 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; +} |