1 2/* ----------------------------------------------------------------------------------------------------------- 3Software License for The Fraunhofer FDK AAC Codec Library for Android 4 5� Copyright 1995 - 2013 Fraunhofer-Gesellschaft zur F�rderung der angewandten Forschung e.V. 6 All rights reserved. 7 8 1. INTRODUCTION 9The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements 10the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio. 11This FDK AAC Codec software is intended to be used on a wide variety of Android devices. 12 13AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual 14audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by 15independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part 16of the MPEG specifications. 17 18Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer) 19may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners 20individually for the purpose of encoding or decoding bit streams in products that are compliant with 21the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license 22these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec 23software may already be covered under those patent licenses when it is used for those licensed purposes only. 24 25Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality, 26are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional 27applications information and documentation. 28 292. COPYRIGHT LICENSE 30 31Redistribution and use in source and binary forms, with or without modification, are permitted without 32payment of copyright license fees provided that you satisfy the following conditions: 33 34You must retain the complete text of this software license in redistributions of the FDK AAC Codec or 35your modifications thereto in source code form. 36 37You must retain the complete text of this software license in the documentation and/or other materials 38provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form. 39You must make available free of charge copies of the complete source code of the FDK AAC Codec and your 40modifications thereto to recipients of copies in binary form. 41 42The name of Fraunhofer may not be used to endorse or promote products derived from this library without 43prior written permission. 44 45You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec 46software or your modifications thereto. 47 48Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software 49and the date of any change. For modified versions of the FDK AAC Codec, the term 50"Fraunhofer FDK AAC Codec Library for Android" must be replaced by the term 51"Third-Party Modified Version of the Fraunhofer FDK AAC Codec Library for Android." 52 533. NO PATENT LICENSE 54 55NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer, 56ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with 57respect to this software. 58 59You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized 60by appropriate patent licenses. 61 624. DISCLAIMER 63 64This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright holders and contributors 65"AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, including but not limited to the implied warranties 66of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 67CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages, 68including but not limited to procurement of substitute goods or services; loss of use, data, or profits, 69or business interruption, however caused and on any theory of liability, whether in contract, strict 70liability, or tort (including negligence), arising in any way out of the use of this software, even if 71advised of the possibility of such damage. 72 735. CONTACT INFORMATION 74 75Fraunhofer Institute for Integrated Circuits IIS 76Attention: Audio and Multimedia Departments - FDK AAC LL 77Am Wolfsmantel 33 7891058 Erlangen, Germany 79 80www.iis.fraunhofer.de/amm 81amm-info@iis.fraunhofer.de 82----------------------------------------------------------------------------------------------------------- */ 83 84/***************************** MPEG-4 AAC Decoder ************************** 85 86 Author(s): Josef Hoepfl 87 Description: joint stereo processing 88 89******************************************************************************/ 90 91#include "stereo.h" 92 93 94#include "aac_rom.h" 95#include "FDK_bitstream.h" 96#include "channelinfo.h" 97 98enum 99{ 100 L = 0, 101 R = 1 102}; 103 104 105int CJointStereo_Read( 106 HANDLE_FDK_BITSTREAM bs, 107 CJointStereoData *pJointStereoData, 108 const int windowGroups, 109 const int scaleFactorBandsTransmitted, 110 const UINT flags 111 ) 112{ 113 int group,band; 114 115 pJointStereoData->MsMaskPresent = (UCHAR) FDKreadBits(bs,2); 116 117 FDKmemclear(pJointStereoData->MsUsed, scaleFactorBandsTransmitted*sizeof(UCHAR)); 118 119 switch (pJointStereoData->MsMaskPresent) 120 { 121 case 0 : /* no M/S */ 122 /* all flags are already cleared */ 123 break ; 124 125 case 1 : /* read ms_used */ 126 127 for (group=0; group<windowGroups; group++) 128 { 129 for (band=0; band<scaleFactorBandsTransmitted; band++) 130 { 131 pJointStereoData->MsUsed[band] |= (FDKreadBits(bs,1) << group); 132 } 133 } 134 break ; 135 136 case 2 : /* full spectrum M/S */ 137 138 for (band=0; band<scaleFactorBandsTransmitted; band++) 139 { 140 pJointStereoData->MsUsed[band] = 255 ; /* set all flags to 1 */ 141 } 142 break ; 143 } 144 145 return 0; 146} 147 148void CJointStereo_ApplyMS( 149 CAacDecoderChannelInfo *pAacDecoderChannelInfo[2], 150 const SHORT *pScaleFactorBandOffsets, 151 const UCHAR *pWindowGroupLength, 152 const int windowGroups, 153 const int scaleFactorBandsTransmittedL, 154 const int scaleFactorBandsTransmittedR 155 ) 156{ 157 CJointStereoData *pJointStereoData = &pAacDecoderChannelInfo[L]->pComData->jointStereoData; 158 int window, group, scaleFactorBandsTransmitted; 159 160 FDK_ASSERT(scaleFactorBandsTransmittedL == scaleFactorBandsTransmittedR); 161 scaleFactorBandsTransmitted = scaleFactorBandsTransmittedL; 162 for (window = 0, group = 0; group < windowGroups; group++) 163 { 164 UCHAR groupMask = 1 << group; 165 166 for (int groupwin=0; groupwin<pWindowGroupLength[group]; groupwin++, window++) 167 { 168 int band; 169 FIXP_DBL *leftSpectrum, *rightSpectrum; 170 SHORT *leftScale = &pAacDecoderChannelInfo[L]->pDynData->aSfbScale[window*16]; 171 SHORT *rightScale = &pAacDecoderChannelInfo[R]->pDynData->aSfbScale[window*16]; 172 173 leftSpectrum = SPEC(pAacDecoderChannelInfo[L]->pSpectralCoefficient, window, pAacDecoderChannelInfo[L]->granuleLength); 174 rightSpectrum = SPEC(pAacDecoderChannelInfo[R]->pSpectralCoefficient, window, pAacDecoderChannelInfo[R]->granuleLength); 175 176 for (band=0; band<scaleFactorBandsTransmitted; band++) 177 { 178 if (pJointStereoData->MsUsed[band] & groupMask) 179 { 180 int lScale=leftScale[band]; 181 int rScale=rightScale[band]; 182 int commonScale=lScale > rScale ? lScale:rScale; 183 184 /* ISO/IEC 14496-3 Chapter 4.6.8.1.1 : 185 M/S joint channel coding can only be used if common_window is �1�. */ 186 FDK_ASSERT(GetWindowSequence(&pAacDecoderChannelInfo[L]->icsInfo) == GetWindowSequence(&pAacDecoderChannelInfo[R]->icsInfo)); 187 FDK_ASSERT(GetWindowShape(&pAacDecoderChannelInfo[L]->icsInfo) == GetWindowShape(&pAacDecoderChannelInfo[R]->icsInfo)); 188 189 commonScale++; 190 leftScale[band]=commonScale; 191 rightScale[band]=commonScale; 192 193 lScale = fMin(DFRACT_BITS-1, commonScale - lScale); 194 rScale = fMin(DFRACT_BITS-1, commonScale - rScale); 195 196 FDK_ASSERT(lScale >= 0 && rScale >= 0); 197 198 for (int index=pScaleFactorBandOffsets[band]; index<pScaleFactorBandOffsets[band+1]; index++) 199 { 200 FIXP_DBL leftCoefficient = leftSpectrum [index] ; 201 FIXP_DBL rightCoefficient = rightSpectrum [index] ; 202 203 leftCoefficient >>= lScale ; 204 rightCoefficient >>= rScale ; 205 206 leftSpectrum [index] = leftCoefficient + rightCoefficient ; 207 rightSpectrum [index] = leftCoefficient - rightCoefficient ; 208 } 209 } 210 } 211 } 212 } 213 214 /* Reset MsUsed flags if no explicit signalling was transmitted. Necessary for intensity coding. 215 PNS correlation signalling was mapped before calling CJointStereo_ApplyMS(). */ 216 if (pJointStereoData->MsMaskPresent == 2) { 217 FDKmemclear(pJointStereoData->MsUsed, JointStereoMaximumBands * sizeof(UCHAR)); 218 } 219} 220 221void CJointStereo_ApplyIS( 222 CAacDecoderChannelInfo *pAacDecoderChannelInfo[2], 223 const SHORT *pScaleFactorBandOffsets, 224 const UCHAR *pWindowGroupLength, 225 const int windowGroups, 226 const int scaleFactorBandsTransmitted, 227 const UINT CommonWindow 228 ) 229{ 230 CJointStereoData *pJointStereoData = &pAacDecoderChannelInfo[L]->pComData->jointStereoData; 231 232 for (int window=0,group=0; group<windowGroups; group++) 233 { 234 UCHAR *CodeBook; 235 SHORT *ScaleFactor; 236 UCHAR groupMask = 1 << group; 237 238 CodeBook = &pAacDecoderChannelInfo[R]->pDynData->aCodeBook[group*16]; 239 ScaleFactor = &pAacDecoderChannelInfo[R]->pDynData->aScaleFactor[group*16]; 240 241 for (int groupwin=0; groupwin<pWindowGroupLength[group]; groupwin++, window++) 242 { 243 FIXP_DBL *leftSpectrum, *rightSpectrum; 244 SHORT *leftScale = &pAacDecoderChannelInfo[L]->pDynData->aSfbScale[window*16]; 245 SHORT *rightScale = &pAacDecoderChannelInfo[R]->pDynData->aSfbScale[window*16]; 246 int band; 247 248 leftSpectrum = SPEC(pAacDecoderChannelInfo[L]->pSpectralCoefficient, window, pAacDecoderChannelInfo[L]->granuleLength); 249 rightSpectrum = SPEC(pAacDecoderChannelInfo[R]->pSpectralCoefficient, window, pAacDecoderChannelInfo[R]->granuleLength); 250 251 for (band=0; band<scaleFactorBandsTransmitted; band++) 252 { 253 if ((CodeBook [band] == INTENSITY_HCB) || 254 (CodeBook [band] == INTENSITY_HCB2)) 255 { 256 int bandScale = -(ScaleFactor [band] + 100) ; 257 258 int msb = bandScale >> 2 ; 259 int lsb = bandScale & 0x03 ; 260 261 /* exponent of MantissaTable[lsb][0] is 1, thus msb+1 below. */ 262 FIXP_DBL scale = MantissaTable[lsb][0]; 263 264 /* ISO/IEC 14496-3 Chapter 4.6.8.2.3 : 265 The use of intensity stereo coding is signaled by the use of the pseudo codebooks 266 INTENSITY_HCB and INTENSITY_HCB2 (15 and 14) only in the right channel of a 267 channel_pair_element() having a common ics_info() (common_window == 1). */ 268 FDK_ASSERT(GetWindowSequence(&pAacDecoderChannelInfo[L]->icsInfo) == GetWindowSequence(&pAacDecoderChannelInfo[R]->icsInfo)); 269 FDK_ASSERT(GetWindowShape(&pAacDecoderChannelInfo[L]->icsInfo) == GetWindowShape(&pAacDecoderChannelInfo[R]->icsInfo)); 270 271 rightScale[band] = leftScale[band]+msb+1; 272 273 if (CommonWindow && (pJointStereoData->MsUsed[band] & groupMask)) 274 { 275 276 if (CodeBook[band] == INTENSITY_HCB) /* _NOT_ in-phase */ 277 { 278 scale = -scale ; 279 } 280 } 281 else 282 { 283 if (CodeBook[band] == INTENSITY_HCB2) /* out-of-phase */ 284 { 285 scale = -scale ; 286 } 287 } 288 289 for (int index=pScaleFactorBandOffsets[band]; index<pScaleFactorBandOffsets[band+1]; index++) 290 { 291 rightSpectrum[index] = fMult(leftSpectrum[index],scale); 292 } 293 } 294 } 295 } 296 } 297} 298