| /* ----------------------------------------------------------------------------- |
| Software License for The Fraunhofer FDK AAC Codec Library for Android |
| |
| © Copyright 1995 - 2018 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 |
| ----------------------------------------------------------------------------- */ |
| |
| /**************************** AAC encoder library ****************************** |
| |
| Author(s): M. Werner |
| |
| 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 *RESTRICT const peChanData, |
| const FIXP_DBL *RESTRICT const sfbEnergyLdData, |
| const FIXP_DBL *RESTRICT const sfbThresholdLdData, |
| const FIXP_DBL *RESTRICT const sfbFormFactorLdData, |
| const INT *RESTRICT const 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 const peChanData, |
| const FIXP_DBL *RESTRICT const sfbEnergyLdData, |
| const FIXP_DBL *RESTRICT const sfbThresholdLdData, |
| const INT sfbCnt, const INT sfbPerGroup, |
| const INT maxSfbPerGroup, |
| const INT *RESTRICT const isBook, |
| const INT *RESTRICT const isScale) { |
| INT sfbGrp, sfb, thisSfb; |
| INT nLines; |
| FIXP_DBL logDataRatio; |
| FIXP_DBL scaleLd = (FIXP_DBL)0; |
| INT lastValIs = 0; |
| |
| FIXP_DBL pe = 0; |
| FIXP_DBL constPart = 0; |
| FIXP_DBL nActiveLines = 0; |
| |
| FIXP_DBL tmpPe, tmpConstPart, tmpNActiveLines; |
| |
| for (sfbGrp = 0; sfbGrp < sfbCnt; sfbGrp += sfbPerGroup) { |
| for (sfb = 0; sfb < maxSfbPerGroup; sfb++) { |
| tmpPe = (FIXP_DBL)0; |
| tmpConstPart = (FIXP_DBL)0; |
| tmpNActiveLines = (FIXP_DBL)0; |
| |
| thisSfb = sfbGrp + sfb; |
| |
| if (sfbEnergyLdData[thisSfb] > sfbThresholdLdData[thisSfb]) { |
| logDataRatio = sfbEnergyLdData[thisSfb] - sfbThresholdLdData[thisSfb]; |
| nLines = peChanData->sfbNLines[thisSfb]; |
| |
| FIXP_DBL factor = nLines << (LD_DATA_SHIFT + PE_CONSTPART_SHIFT + 1); |
| if (logDataRatio >= C1LdData) { |
| /* scale sfbPe and sfbConstPart with PE_CONSTPART_SHIFT */ |
| tmpPe = fMultDiv2(logDataRatio, factor); |
| tmpConstPart = fMultDiv2(sfbEnergyLdData[thisSfb] + scaleLd, factor); |
| } else { |
| /* scale sfbPe and sfbConstPart with PE_CONSTPART_SHIFT */ |
| tmpPe = fMultDiv2( |
| ((FIXP_DBL)C2LdData + fMult(C3LdData, logDataRatio)), factor); |
| tmpConstPart = |
| fMultDiv2(((FIXP_DBL)C2LdData + |
| fMult(C3LdData, sfbEnergyLdData[thisSfb] + scaleLd)), |
| factor); |
| |
| nLines = fMultI(C3LdData, nLines); |
| } |
| tmpNActiveLines = (FIXP_DBL)nLines; |
| } else if (isBook[thisSfb]) { |
| /* provide for cost of scale factor for Intensity */ |
| INT delta = isScale[thisSfb] - lastValIs; |
| lastValIs = isScale[thisSfb]; |
| peChanData->sfbPe[thisSfb] = FDKaacEnc_bitCountScalefactorDelta(delta) |
| << PE_CONSTPART_SHIFT; |
| peChanData->sfbConstPart[thisSfb] = 0; |
| peChanData->sfbNActiveLines[thisSfb] = 0; |
| } |
| peChanData->sfbPe[thisSfb] = tmpPe; |
| peChanData->sfbConstPart[thisSfb] = tmpConstPart; |
| peChanData->sfbNActiveLines[thisSfb] = tmpNActiveLines; |
| |
| /* sum up peChanData values */ |
| pe += tmpPe; |
| constPart += tmpConstPart; |
| nActiveLines += tmpNActiveLines; |
| } |
| } |
| |
| /* correct scaled pe and constPart values */ |
| peChanData->pe = pe >> PE_CONSTPART_SHIFT; |
| peChanData->constPart = constPart >> PE_CONSTPART_SHIFT; |
| |
| peChanData->nActiveLines = nActiveLines; |
| } |