| |
| /* ----------------------------------------------------------------------------------------------------------- |
| Software License for The Fraunhofer FDK AAC Codec Library for Android |
| |
| © Copyright 1995 - 2012 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-4 AAC Encoder ************************** |
| |
| Initial author: M. Werner |
| contents/description: Band/Line energy calculations |
| |
| ******************************************************************************/ |
| |
| #include "band_nrg.h" |
| |
| |
| /***************************************************************************** |
| functionname: FDKaacEnc_CalcSfbMaxScaleSpec |
| description: |
| input: |
| output: |
| *****************************************************************************/ |
| void |
| FDKaacEnc_CalcSfbMaxScaleSpec(const FIXP_DBL *RESTRICT mdctSpectrum, |
| const INT *RESTRICT bandOffset, |
| INT *RESTRICT sfbMaxScaleSpec, |
| const INT numBands) |
| { |
| INT i,j; |
| FIXP_DBL maxSpc, tmp; |
| |
| for(i=0; i<numBands; i++) { |
| maxSpc = (FIXP_DBL)0; |
| for (j=bandOffset[i]; j<bandOffset[i+1]; j++) { |
| tmp = fixp_abs(mdctSpectrum[j]); |
| maxSpc = fixMax(maxSpc, tmp); |
| } |
| sfbMaxScaleSpec[i] = (maxSpc==(FIXP_DBL)0) ? (DFRACT_BITS-2) : CntLeadingZeros(maxSpc)-1; |
| /* CountLeadingBits() is not necessary here since test value is always > 0 */ |
| } |
| } |
| |
| /***************************************************************************** |
| functionname: FDKaacEnc_CheckBandEnergyOptim |
| description: |
| input: |
| output: |
| *****************************************************************************/ |
| FIXP_DBL |
| FDKaacEnc_CheckBandEnergyOptim(const FIXP_DBL *RESTRICT mdctSpectrum, |
| INT *RESTRICT sfbMaxScaleSpec, |
| const INT *RESTRICT bandOffset, |
| const INT numBands, |
| FIXP_DBL *RESTRICT bandEnergy, |
| FIXP_DBL *RESTRICT bandEnergyLdData, |
| INT minSpecShift) |
| { |
| INT i, j, scale, nr = 0; |
| FIXP_DBL maxNrgLd = FL2FXCONST_DBL(-1.0f); |
| FIXP_DBL maxNrg = 0; |
| FIXP_DBL spec; |
| |
| for(i=0; i<numBands; i++) { |
| scale = fixMax(0, sfbMaxScaleSpec[i]-4); |
| FIXP_DBL tmp = 0; |
| for (j=bandOffset[i]; j<bandOffset[i+1]; j++){ |
| spec = mdctSpectrum[j]<<scale; |
| tmp = fPow2AddDiv2(tmp, spec); |
| } |
| bandEnergy[i] = tmp<<1; |
| |
| /* calculate ld of bandNrg, subtract scaling */ |
| bandEnergyLdData[i] = CalcLdData(bandEnergy[i]); |
| if (bandEnergyLdData[i] != FL2FXCONST_DBL(-1.0f)) { |
| bandEnergyLdData[i] -= scale*FL2FXCONST_DBL(2.0/64); |
| } |
| /* find index of maxNrg */ |
| if (bandEnergyLdData[i] > maxNrgLd) { |
| maxNrgLd = bandEnergyLdData[i]; |
| nr = i; |
| } |
| } |
| |
| /* return unscaled maxNrg*/ |
| scale = fixMax(0,sfbMaxScaleSpec[nr]-4); |
| scale = fixMax(2*(minSpecShift-scale),-(DFRACT_BITS-1)); |
| |
| maxNrg = scaleValue(bandEnergy[nr], scale); |
| |
| return maxNrg; |
| } |
| |
| /***************************************************************************** |
| functionname: FDKaacEnc_CalcBandEnergyOptimLong |
| description: |
| input: |
| output: |
| *****************************************************************************/ |
| INT |
| FDKaacEnc_CalcBandEnergyOptimLong(const FIXP_DBL *RESTRICT mdctSpectrum, |
| INT *RESTRICT sfbMaxScaleSpec, |
| const INT *RESTRICT bandOffset, |
| const INT numBands, |
| FIXP_DBL *RESTRICT bandEnergy, |
| FIXP_DBL *RESTRICT bandEnergyLdData) |
| { |
| INT i, j, shiftBits = 0; |
| FIXP_DBL maxNrgLd = FL2FXCONST_DBL(0.0f); |
| |
| FIXP_DBL spec; |
| |
| for(i=0; i<numBands; i++) { |
| INT leadingBits = sfbMaxScaleSpec[i]-4; /* max sfbWidth = 96 ; 2^7=128 => 7/2 = 4 (spc*spc) */ |
| FIXP_DBL tmp = FL2FXCONST_DBL(0.0); |
| /* don't use scaleValue() here, it increases workload quite sufficiently... */ |
| if (leadingBits>=0) { |
| for (j=bandOffset[i];j<bandOffset[i+1];j++) { |
| spec = mdctSpectrum[j]<<leadingBits; |
| tmp = fPow2AddDiv2(tmp, spec); |
| } |
| } else { |
| INT shift = -leadingBits; |
| for (j=bandOffset[i];j<bandOffset[i+1];j++){ |
| spec = mdctSpectrum[j]>>shift; |
| tmp = fPow2AddDiv2(tmp, spec); |
| } |
| } |
| bandEnergy[i] = tmp<<1; |
| } |
| |
| /* calculate ld of bandNrg, subtract scaling */ |
| LdDataVector(bandEnergy, bandEnergyLdData, numBands); |
| for(i=numBands; i--!=0; ) { |
| FIXP_DBL scaleDiff = (sfbMaxScaleSpec[i]-4)*FL2FXCONST_DBL(2.0/64); |
| |
| bandEnergyLdData[i] = (bandEnergyLdData[i] >= ((FL2FXCONST_DBL(-1.f)>>1) + (scaleDiff>>1))) |
| ? bandEnergyLdData[i]-scaleDiff : FL2FXCONST_DBL(-1.f); |
| /* find maxNrgLd */ |
| maxNrgLd = fixMax(maxNrgLd, bandEnergyLdData[i]); |
| } |
| |
| if (maxNrgLd<=(FIXP_DBL)0) |
| { |
| for(i=numBands; i--!=0; ) |
| { |
| INT scale = fixMin((sfbMaxScaleSpec[i]-4)<<1,(DFRACT_BITS-1)); |
| bandEnergy[i] = scaleValue(bandEnergy[i], -scale); |
| } |
| return 0; |
| } |
| else |
| { /* scale down NRGs */ |
| while (maxNrgLd>FL2FXCONST_DBL(0.0f)) |
| { |
| maxNrgLd -= FL2FXCONST_DBL(2.0/64); |
| shiftBits++; |
| } |
| for(i=numBands; i--!=0; ) |
| { |
| INT scale = fixMin( ((sfbMaxScaleSpec[i]-4)+shiftBits)<<1, (DFRACT_BITS-1)); |
| bandEnergyLdData[i] -= shiftBits*FL2FXCONST_DBL(2.0/64); |
| bandEnergy[i] = scaleValue(bandEnergy[i], -scale); |
| } |
| return shiftBits; |
| } |
| } |
| |
| |
| /***************************************************************************** |
| functionname: FDKaacEnc_CalcBandEnergyOptimShort |
| description: |
| input: |
| output: |
| *****************************************************************************/ |
| void |
| FDKaacEnc_CalcBandEnergyOptimShort(const FIXP_DBL *RESTRICT mdctSpectrum, |
| INT *RESTRICT sfbMaxScaleSpec, |
| const INT *RESTRICT bandOffset, |
| const INT numBands, |
| FIXP_DBL *RESTRICT bandEnergy) |
| { |
| INT i, j; |
| |
| for(i=0; i<numBands; i++) |
| { |
| int leadingBits = fixMax(0,sfbMaxScaleSpec[i]-4); /* max sfbWidth = 96 ; 2^7=128 => 7/2 = 4 (spc*spc) */ |
| FIXP_DBL tmp = FL2FXCONST_DBL(0.0); |
| for (j=bandOffset[i];j<bandOffset[i+1];j++) |
| { |
| FIXP_DBL spec = mdctSpectrum[j]<<leadingBits; |
| tmp = fPow2AddDiv2(tmp, spec); |
| } |
| bandEnergy[i] = tmp<<1; |
| } |
| |
| for(i=0; i<numBands; i++) |
| { |
| INT scale = 2*fixMax(0,sfbMaxScaleSpec[i]-4); /* max sfbWidth = 96 ; 2^7=128 => 7/2 = 4 (spc*spc) */ |
| scale = fixMin(scale,(DFRACT_BITS-1)); |
| bandEnergy[i] >>= scale; |
| } |
| } |
| |
| |
| /***************************************************************************** |
| functionname: FDKaacEnc_CalcBandNrgMSOpt |
| description: |
| input: |
| output: |
| *****************************************************************************/ |
| void FDKaacEnc_CalcBandNrgMSOpt(const FIXP_DBL *RESTRICT mdctSpectrumLeft, |
| const FIXP_DBL *RESTRICT mdctSpectrumRight, |
| INT *RESTRICT sfbMaxScaleSpecLeft, |
| INT *RESTRICT sfbMaxScaleSpecRight, |
| const INT *RESTRICT bandOffset, |
| const INT numBands, |
| FIXP_DBL *RESTRICT bandEnergyMid, |
| FIXP_DBL *RESTRICT bandEnergySide, |
| INT calcLdData, |
| FIXP_DBL *RESTRICT bandEnergyMidLdData, |
| FIXP_DBL *RESTRICT bandEnergySideLdData) |
| { |
| INT i, j, minScale; |
| FIXP_DBL NrgMid, NrgSide, specm, specs; |
| |
| for (i=0; i<numBands; i++) { |
| |
| NrgMid = NrgSide = FL2FXCONST_DBL(0.0); |
| minScale = fixMin(sfbMaxScaleSpecLeft[i], sfbMaxScaleSpecRight[i])-4; |
| minScale = fixMax(0, minScale); |
| |
| if (minScale > 0) { |
| for (j=bandOffset[i];j<bandOffset[i+1];j++) { |
| FIXP_DBL specL = mdctSpectrumLeft[j]<<(minScale-1); |
| FIXP_DBL specR = mdctSpectrumRight[j]<<(minScale-1); |
| specm = specL + specR; |
| specs = specL - specR; |
| NrgMid = fPow2AddDiv2(NrgMid, specm); |
| NrgSide = fPow2AddDiv2(NrgSide, specs); |
| } |
| } else { |
| for (j=bandOffset[i];j<bandOffset[i+1];j++) { |
| FIXP_DBL specL = mdctSpectrumLeft[j]>>1; |
| FIXP_DBL specR = mdctSpectrumRight[j]>>1; |
| specm = specL + specR; |
| specs = specL - specR; |
| NrgMid = fPow2AddDiv2(NrgMid, specm); |
| NrgSide = fPow2AddDiv2(NrgSide, specs); |
| } |
| } |
| bandEnergyMid[i] = NrgMid<<1; |
| bandEnergySide[i] = NrgSide<<1; |
| } |
| |
| if(calcLdData) { |
| LdDataVector(bandEnergyMid, bandEnergyMidLdData, numBands); |
| LdDataVector(bandEnergySide, bandEnergySideLdData, numBands); |
| } |
| |
| for (i=0; i<numBands; i++) |
| { |
| INT minScale = fixMin(sfbMaxScaleSpecLeft[i], sfbMaxScaleSpecRight[i]); |
| INT scale = fixMax(0, 2*(minScale-4)); |
| |
| if (calcLdData) |
| { |
| /* using the minimal scaling of left and right channel can cause very small energies; |
| check ldNrg before subtract scaling multiplication: fract*INT we don't need fMult */ |
| |
| int minus = scale*FL2FXCONST_DBL(1.0/64); |
| |
| if (bandEnergyMidLdData[i] != FL2FXCONST_DBL(-1.0f)) |
| bandEnergyMidLdData[i] -= minus; |
| |
| if (bandEnergySideLdData[i] != FL2FXCONST_DBL(-1.0f)) |
| bandEnergySideLdData[i] -= minus; |
| } |
| scale = fixMin(scale, (DFRACT_BITS-1)); |
| bandEnergyMid[i] >>= scale; |
| bandEnergySide[i] >>= scale; |
| } |
| } |
