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| /* ----------------------------------------------------------------------------------------------------------- |
| Software License for The Fraunhofer FDK AAC Codec Library for Android |
| |
| © Copyright 1995 - 2013 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. |
| All rights reserved. |
| |
| 1. INTRODUCTION |
| The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements |
| the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio. |
| This FDK AAC Codec software is intended to be used on a wide variety of Android devices. |
| |
| AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual |
| audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by |
| independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part |
| of the MPEG specifications. |
| |
| Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer) |
| may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners |
| individually for the purpose of encoding or decoding bit streams in products that are compliant with |
| the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license |
| these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec |
| software may already be covered under those patent licenses when it is used for those licensed purposes only. |
| |
| Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality, |
| are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional |
| applications information and documentation. |
| |
| 2. COPYRIGHT LICENSE |
| |
| Redistribution and use in source and binary forms, with or without modification, are permitted without |
| payment of copyright license fees provided that you satisfy the following conditions: |
| |
| You must retain the complete text of this software license in redistributions of the FDK AAC Codec or |
| your modifications thereto in source code form. |
| |
| You must retain the complete text of this software license in the documentation and/or other materials |
| provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form. |
| You must make available free of charge copies of the complete source code of the FDK AAC Codec and your |
| modifications thereto to recipients of copies in binary form. |
| |
| The name of Fraunhofer may not be used to endorse or promote products derived from this library without |
| prior written permission. |
| |
| You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec |
| software or your modifications thereto. |
| |
| Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software |
| and the date of any change. For modified versions of the FDK AAC Codec, the term |
| "Fraunhofer FDK AAC Codec Library for Android" must be replaced by the term |
| "Third-Party Modified Version of the Fraunhofer FDK AAC Codec Library for Android." |
| |
| 3. NO PATENT LICENSE |
| |
| NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer, |
| ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with |
| respect to this software. |
| |
| You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized |
| by appropriate patent licenses. |
| |
| 4. DISCLAIMER |
| |
| This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright holders and contributors |
| "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, including but not limited to the implied warranties |
| of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR |
| CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages, |
| including but not limited to procurement of substitute goods or services; loss of use, data, or profits, |
| or business interruption, however caused and on any theory of liability, whether in contract, strict |
| liability, or tort (including negligence), arising in any way out of the use of this software, even if |
| advised of the possibility of such damage. |
| |
| 5. CONTACT INFORMATION |
| |
| Fraunhofer Institute for Integrated Circuits IIS |
| Attention: Audio and Multimedia Departments - FDK AAC LL |
| Am Wolfsmantel 33 |
| 91058 Erlangen, Germany |
| |
| www.iis.fraunhofer.de/amm |
| amm-info@iis.fraunhofer.de |
| ----------------------------------------------------------------------------------------------------------- */ |
| |
| /******************************** MPEG Audio Encoder ************************** |
| |
| 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); |
| /* Make sure sfbNLines is never greater than sfbWidth due to unaccuracies (e.g. sfbEnergyLdData[sfbGrp+sfb] = 0x80000000) */ |
| peChanData->sfbNLines[sfbGrp+sfb] = fMin(sfbWidth, peChanData->sfbNLines[sfbGrp+sfb]); |
| } |
| 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[sfbGrp+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; |
| } |