| |
| /* ----------------------------------------------------------------------------------------------------------- |
| 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: Quantization |
| |
| ******************************************************************************/ |
| |
| #include "quantize.h" |
| |
| #include "aacEnc_rom.h" |
| |
| /***************************************************************************** |
| |
| functionname: FDKaacEnc_quantizeLines |
| description: quantizes spectrum lines |
| returns: |
| input: global gain, number of lines to process, spectral data |
| output: quantized spectrum |
| |
| *****************************************************************************/ |
| static void FDKaacEnc_quantizeLines(INT gain, |
| INT noOfLines, |
| FIXP_DBL *mdctSpectrum, |
| SHORT *quaSpectrum) |
| { |
| int line; |
| FIXP_DBL k = FL2FXCONST_DBL(-0.0946f + 0.5f)>>16; |
| FIXP_QTD quantizer = FDKaacEnc_quantTableQ[(-gain)&3]; |
| INT quantizershift = ((-gain)>>2)+1; |
| |
| |
| for (line = 0; line < noOfLines; line++) |
| { |
| FIXP_DBL accu = fMultDiv2(mdctSpectrum[line],quantizer); |
| |
| if (accu < FL2FXCONST_DBL(0.0f)) |
| { |
| accu=-accu; |
| /* normalize */ |
| INT accuShift = CntLeadingZeros(accu) - 1; /* CountLeadingBits() is not necessary here since test value is always > 0 */ |
| accu <<= accuShift; |
| INT tabIndex = (INT)(accu>>(DFRACT_BITS-2-MANT_DIGITS))&(~MANT_SIZE); |
| INT totalShift = quantizershift-accuShift+1; |
| accu = fMultDiv2(FDKaacEnc_mTab_3_4[tabIndex],FDKaacEnc_quantTableE[totalShift&3]); |
| totalShift = (16-4)-(3*(totalShift>>2)); |
| FDK_ASSERT(totalShift >=0); /* MAX_QUANT_VIOLATION */ |
| accu >>= fixMin(totalShift,DFRACT_BITS-1); |
| quaSpectrum[line] = (SHORT)(-((LONG)(k + accu) >> (DFRACT_BITS-1-16))); |
| } |
| else if(accu > FL2FXCONST_DBL(0.0f)) |
| { |
| /* normalize */ |
| INT accuShift = CntLeadingZeros(accu) - 1; /* CountLeadingBits() is not necessary here since test value is always > 0 */ |
| accu <<= accuShift; |
| INT tabIndex = (INT)(accu>>(DFRACT_BITS-2-MANT_DIGITS))&(~MANT_SIZE); |
| INT totalShift = quantizershift-accuShift+1; |
| accu = fMultDiv2(FDKaacEnc_mTab_3_4[tabIndex],FDKaacEnc_quantTableE[totalShift&3]); |
| totalShift = (16-4)-(3*(totalShift>>2)); |
| FDK_ASSERT(totalShift >=0); /* MAX_QUANT_VIOLATION */ |
| accu >>= fixMin(totalShift,DFRACT_BITS-1); |
| quaSpectrum[line] = (SHORT)((LONG)(k + accu) >> (DFRACT_BITS-1-16)); |
| } |
| else |
| quaSpectrum[line]=0; |
| } |
| } |
| |
| |
| /***************************************************************************** |
| |
| functionname:iFDKaacEnc_quantizeLines |
| description: iquantizes spectrum lines |
| mdctSpectrum = iquaSpectrum^4/3 *2^(0.25*gain) |
| input: global gain, number of lines to process,quantized spectrum |
| output: spectral data |
| |
| *****************************************************************************/ |
| static void FDKaacEnc_invQuantizeLines(INT gain, |
| INT noOfLines, |
| SHORT *quantSpectrum, |
| FIXP_DBL *mdctSpectrum) |
| |
| { |
| INT iquantizermod; |
| INT iquantizershift; |
| INT line; |
| |
| iquantizermod = gain&3; |
| iquantizershift = gain>>2; |
| |
| for (line = 0; line < noOfLines; line++) { |
| |
| if(quantSpectrum[line] < 0) { |
| FIXP_DBL accu; |
| INT ex,specExp,tabIndex; |
| FIXP_DBL s,t; |
| |
| accu = (FIXP_DBL) -quantSpectrum[line]; |
| |
| ex = CountLeadingBits(accu); |
| accu <<= ex; |
| specExp = (DFRACT_BITS-1) - ex; |
| |
| FDK_ASSERT(specExp < 14); /* this fails if abs(value) > 8191 */ |
| |
| tabIndex = (INT)(accu>>(DFRACT_BITS-2-MANT_DIGITS))&(~MANT_SIZE); |
| |
| /* calculate "mantissa" ^4/3 */ |
| s = FDKaacEnc_mTab_4_3Elc[tabIndex]; |
| |
| /* get approperiate exponent multiplier for specExp^3/4 combined with scfMod */ |
| t = FDKaacEnc_specExpMantTableCombElc[iquantizermod][specExp]; |
| |
| /* multiply "mantissa" ^4/3 with exponent multiplier */ |
| accu = fMult(s,t); |
| |
| /* get approperiate exponent shifter */ |
| specExp = FDKaacEnc_specExpTableComb[iquantizermod][specExp]-1; /* -1 to avoid overflows in accu */ |
| |
| if ((-iquantizershift-specExp) < 0) |
| accu <<= -(-iquantizershift-specExp); |
| else |
| accu >>= -iquantizershift-specExp; |
| |
| mdctSpectrum[line] = -accu; |
| } |
| else if (quantSpectrum[line] > 0) { |
| FIXP_DBL accu; |
| INT ex,specExp,tabIndex; |
| FIXP_DBL s,t; |
| |
| accu = (FIXP_DBL)(INT)quantSpectrum[line]; |
| |
| ex = CountLeadingBits(accu); |
| accu <<= ex; |
| specExp = (DFRACT_BITS-1) - ex; |
| |
| FDK_ASSERT(specExp < 14); /* this fails if abs(value) > 8191 */ |
| |
| tabIndex = (INT)(accu>>(DFRACT_BITS-2-MANT_DIGITS))&(~MANT_SIZE); |
| |
| /* calculate "mantissa" ^4/3 */ |
| s = FDKaacEnc_mTab_4_3Elc[tabIndex]; |
| |
| /* get approperiate exponent multiplier for specExp^3/4 combined with scfMod */ |
| t = FDKaacEnc_specExpMantTableCombElc[iquantizermod][specExp]; |
| |
| /* multiply "mantissa" ^4/3 with exponent multiplier */ |
| accu = fMult(s,t); |
| |
| /* get approperiate exponent shifter */ |
| specExp = FDKaacEnc_specExpTableComb[iquantizermod][specExp]-1; /* -1 to avoid overflows in accu */ |
| |
| if (( -iquantizershift-specExp) < 0) |
| accu <<= -(-iquantizershift-specExp); |
| else |
| accu >>= -iquantizershift-specExp; |
| |
| mdctSpectrum[line] = accu; |
| } |
| else { |
| mdctSpectrum[line] = FL2FXCONST_DBL(0.0f); |
| } |
| } |
| } |
| |
| /***************************************************************************** |
| |
| functionname: FDKaacEnc_QuantizeSpectrum |
| description: quantizes the entire spectrum |
| returns: |
| input: number of scalefactor bands to be quantized, ... |
| output: quantized spectrum |
| |
| *****************************************************************************/ |
| void FDKaacEnc_QuantizeSpectrum(INT sfbCnt, |
| INT maxSfbPerGroup, |
| INT sfbPerGroup, |
| INT *sfbOffset, |
| FIXP_DBL *mdctSpectrum, |
| INT globalGain, |
| INT *scalefactors, |
| SHORT *quantizedSpectrum) |
| { |
| INT sfbOffs,sfb; |
| |
| /* in FDKaacEnc_quantizeLines quaSpectrum is calculated with: |
| spec^(3/4) * 2^(-3/16*QSS) * 2^(3/4*scale) + k |
| simplify scaling calculation and reduce QSS before: |
| spec^(3/4) * 2^(-3/16*(QSS - 4*scale)) */ |
| |
| for(sfbOffs=0;sfbOffs<sfbCnt;sfbOffs+=sfbPerGroup) |
| for (sfb = 0; sfb < maxSfbPerGroup; sfb++) |
| { |
| INT scalefactor = scalefactors[sfbOffs+sfb] ; |
| |
| FDKaacEnc_quantizeLines(globalGain - scalefactor, /* QSS */ |
| sfbOffset[sfbOffs+sfb+1] - sfbOffset[sfbOffs+sfb], |
| mdctSpectrum + sfbOffset[sfbOffs+sfb], |
| quantizedSpectrum + sfbOffset[sfbOffs+sfb]); |
| } |
| } |
| |
| /***************************************************************************** |
| |
| functionname: FDKaacEnc_calcSfbDist |
| description: calculates distortion of quantized values |
| returns: distortion |
| input: gain, number of lines to process, spectral data |
| output: |
| |
| *****************************************************************************/ |
| FIXP_DBL FDKaacEnc_calcSfbDist(FIXP_DBL *mdctSpectrum, |
| SHORT *quantSpectrum, |
| INT noOfLines, |
| INT gain |
| ) |
| { |
| INT i,scale; |
| FIXP_DBL xfsf; |
| FIXP_DBL diff; |
| FIXP_DBL invQuantSpec; |
| |
| xfsf = FL2FXCONST_DBL(0.0f); |
| |
| for (i=0; i<noOfLines; i++) { |
| /* quantization */ |
| FDKaacEnc_quantizeLines(gain, |
| 1, |
| &mdctSpectrum[i], |
| &quantSpectrum[i]); |
| |
| if (fAbs(quantSpectrum[i])>MAX_QUANT) { |
| return FL2FXCONST_DBL(0.0f); |
| } |
| /* inverse quantization */ |
| FDKaacEnc_invQuantizeLines(gain,1,&quantSpectrum[i],&invQuantSpec); |
| |
| /* dist */ |
| diff = fixp_abs(fixp_abs(invQuantSpec) - fixp_abs(mdctSpectrum[i]>>1)); |
| |
| scale = CountLeadingBits(diff); |
| diff = scaleValue(diff, scale); |
| diff = fPow2(diff); |
| scale = fixMin(2*(scale-1), DFRACT_BITS-1); |
| |
| diff = scaleValue(diff, -scale); |
| |
| xfsf = xfsf + diff; |
| } |
| |
| xfsf = CalcLdData(xfsf); |
| |
| return xfsf; |
| } |
| |
| /***************************************************************************** |
| |
| functionname: FDKaacEnc_calcSfbQuantEnergyAndDist |
| description: calculates energy and distortion of quantized values |
| returns: |
| input: gain, number of lines to process, quantized spectral data, |
| spectral data |
| output: energy, distortion |
| |
| *****************************************************************************/ |
| void FDKaacEnc_calcSfbQuantEnergyAndDist(FIXP_DBL *mdctSpectrum, |
| SHORT *quantSpectrum, |
| INT noOfLines, |
| INT gain, |
| FIXP_DBL *en, |
| FIXP_DBL *dist) |
| { |
| INT i,scale; |
| FIXP_DBL invQuantSpec; |
| FIXP_DBL diff; |
| |
| FIXP_DBL energy = FL2FXCONST_DBL(0.0f); |
| FIXP_DBL distortion = FL2FXCONST_DBL(0.0f); |
| |
| for (i=0; i<noOfLines; i++) { |
| |
| if (fAbs(quantSpectrum[i])>MAX_QUANT) { |
| *en = FL2FXCONST_DBL(0.0f); |
| *dist = FL2FXCONST_DBL(0.0f); |
| return; |
| } |
| |
| /* inverse quantization */ |
| FDKaacEnc_invQuantizeLines(gain,1,&quantSpectrum[i],&invQuantSpec); |
| |
| /* energy */ |
| energy += fPow2(invQuantSpec); |
| |
| /* dist */ |
| diff = fixp_abs(fixp_abs(invQuantSpec) - fixp_abs(mdctSpectrum[i]>>1)); |
| |
| scale = CountLeadingBits(diff); |
| diff = scaleValue(diff, scale); |
| diff = fPow2(diff); |
| |
| scale = fixMin(2*(scale-1), DFRACT_BITS-1); |
| |
| diff = scaleValue(diff, -scale); |
| |
| distortion += diff; |
| } |
| |
| *en = CalcLdData(energy)+FL2FXCONST_DBL(0.03125f); |
| *dist = CalcLdData(distortion); |
| } |
| |
