1 2 /* ----------------------------------------------------------------------------------------------------------- 3 Software License for The Fraunhofer FDK AAC Codec Library for Android 4 5 Copyright 1995 - 2013 Fraunhofer-Gesellschaft zur Frderung der angewandten Forschung e.V. 6 All rights reserved. 7 8 1. INTRODUCTION 9 The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements 10 the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio. 11 This FDK AAC Codec software is intended to be used on a wide variety of Android devices. 12 13 AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual 14 audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by 15 independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part 16 of the MPEG specifications. 17 18 Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer) 19 may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners 20 individually for the purpose of encoding or decoding bit streams in products that are compliant with 21 the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license 22 these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec 23 software may already be covered under those patent licenses when it is used for those licensed purposes only. 24 25 Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality, 26 are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional 27 applications information and documentation. 28 29 2. COPYRIGHT LICENSE 30 31 Redistribution and use in source and binary forms, with or without modification, are permitted without 32 payment of copyright license fees provided that you satisfy the following conditions: 33 34 You must retain the complete text of this software license in redistributions of the FDK AAC Codec or 35 your modifications thereto in source code form. 36 37 You must retain the complete text of this software license in the documentation and/or other materials 38 provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form. 39 You must make available free of charge copies of the complete source code of the FDK AAC Codec and your 40 modifications thereto to recipients of copies in binary form. 41 42 The name of Fraunhofer may not be used to endorse or promote products derived from this library without 43 prior written permission. 44 45 You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec 46 software or your modifications thereto. 47 48 Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software 49 and 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 53 3. NO PATENT LICENSE 54 55 NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer, 56 ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with 57 respect to this software. 58 59 You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized 60 by appropriate patent licenses. 61 62 4. DISCLAIMER 63 64 This 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 66 of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 67 CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages, 68 including but not limited to procurement of substitute goods or services; loss of use, data, or profits, 69 or business interruption, however caused and on any theory of liability, whether in contract, strict 70 liability, or tort (including negligence), arising in any way out of the use of this software, even if 71 advised of the possibility of such damage. 72 73 5. CONTACT INFORMATION 74 75 Fraunhofer Institute for Integrated Circuits IIS 76 Attention: Audio and Multimedia Departments - FDK AAC LL 77 Am Wolfsmantel 33 78 91058 Erlangen, Germany 79 80 www.iis.fraunhofer.de/amm 81 amm-info (at) iis.fraunhofer.de 82 ----------------------------------------------------------------------------------------------------------- */ 83 84 /***************************** MPEG-4 AAC Decoder ************************** 85 86 Author(s): Josef Hoepfl 87 Description: perceptual noise substitution tool 88 89 ******************************************************************************/ 90 91 #include "aacdec_pns.h" 92 93 94 #include "aac_ram.h" 95 #include "aac_rom.h" 96 #include "channelinfo.h" 97 #include "block.h" 98 #include "FDK_bitstream.h" 99 100 #include "genericStds.h" 101 102 103 #define NOISE_OFFSET 90 /* cf. ISO 14496-3 p. 175 */ 104 105 /*! 106 \brief Reset InterChannel and PNS data 107 108 The function resets the InterChannel and PNS data 109 */ 110 void CPns_ResetData( 111 CPnsData *pPnsData, 112 CPnsInterChannelData *pPnsInterChannelData 113 ) 114 { 115 /* Assign pointer always, since pPnsData is not persistent data */ 116 pPnsData->pPnsInterChannelData = pPnsInterChannelData; 117 pPnsData->PnsActive = 0; 118 pPnsData->CurrentEnergy = 0; 119 120 FDKmemclear(pPnsData->pnsUsed,(8*16)*sizeof(UCHAR)); 121 FDKmemclear(pPnsInterChannelData->correlated,(8*16)*sizeof(UCHAR)); 122 } 123 124 /*! 125 \brief Initialize PNS data 126 127 The function initializes the PNS data 128 */ 129 void CPns_InitPns( 130 CPnsData *pPnsData, 131 CPnsInterChannelData *pPnsInterChannelData, 132 INT* currentSeed, INT* randomSeed) 133 { 134 /* save pointer to inter channel data */ 135 pPnsData->pPnsInterChannelData = pPnsInterChannelData; 136 137 /* use pointer because seed has to be 138 same, left and right channel ! */ 139 pPnsData->currentSeed = currentSeed; 140 pPnsData->randomSeed = randomSeed; 141 } 142 143 /*! 144 \brief Indicates if PNS is used 145 146 The function returns a value indicating whether PNS is used or not 147 acordding to the noise energy 148 149 \return PNS used 150 */ 151 int CPns_IsPnsUsed (const CPnsData *pPnsData, 152 const int group, 153 const int band) 154 { 155 unsigned pns_band = group*16+band; 156 157 return pPnsData->pnsUsed[pns_band] & (UCHAR)1; 158 } 159 160 /*! 161 \brief Set correlation 162 163 The function activates the noise correlation between the channel pair 164 */ 165 void CPns_SetCorrelation(CPnsData *pPnsData, 166 const int group, 167 const int band, 168 const int outofphase) 169 { 170 CPnsInterChannelData *pInterChannelData = pPnsData->pPnsInterChannelData; 171 unsigned pns_band = group*16+band; 172 173 pInterChannelData->correlated[pns_band] = (outofphase) ? 3 : 1; 174 } 175 176 /*! 177 \brief Indicates if correlation is used 178 179 The function indicates if the noise correlation between the channel pair 180 is activated 181 182 \return PNS is correlated 183 */ 184 static 185 int CPns_IsCorrelated(const CPnsData *pPnsData, 186 const int group, 187 const int band) 188 { 189 CPnsInterChannelData *pInterChannelData = pPnsData->pPnsInterChannelData; 190 unsigned pns_band = group*16+band; 191 192 return (pInterChannelData->correlated[pns_band] & 0x01) ? 1 : 0; 193 } 194 195 /*! 196 \brief Indicates if correlated out of phase mode is used. 197 198 The function indicates if the noise correlation between the channel pair 199 is activated in out-of-phase mode. 200 201 \return PNS is out-of-phase 202 */ 203 static 204 int CPns_IsOutOfPhase(const CPnsData *pPnsData, 205 const int group, 206 const int band) 207 { 208 CPnsInterChannelData *pInterChannelData = pPnsData->pPnsInterChannelData; 209 unsigned pns_band = group*16+band; 210 211 return (pInterChannelData->correlated[pns_band] & 0x02) ? 1 : 0; 212 } 213 214 /*! 215 \brief Read PNS information 216 217 The function reads the PNS information from the bitstream 218 */ 219 void CPns_Read (CPnsData *pPnsData, 220 HANDLE_FDK_BITSTREAM bs, 221 const CodeBookDescription *hcb, 222 SHORT *pScaleFactor, 223 UCHAR global_gain, 224 int band, 225 int group /* = 0 */) 226 { 227 int delta ; 228 UINT pns_band = group*16+band; 229 230 if (pPnsData->PnsActive) { 231 /* Next PNS band case */ 232 delta = CBlock_DecodeHuffmanWord (bs, hcb) - 60; 233 } else { 234 /* First PNS band case */ 235 int noiseStartValue = FDKreadBits(bs,9); 236 237 delta = noiseStartValue - 256 ; 238 pPnsData->PnsActive = 1; 239 pPnsData->CurrentEnergy = global_gain - NOISE_OFFSET; 240 } 241 242 pPnsData->CurrentEnergy += delta ; 243 pScaleFactor[pns_band] = pPnsData->CurrentEnergy; 244 245 pPnsData->pnsUsed[pns_band] = 1; 246 } 247 248 249 /** 250 * \brief Generate a vector of noise of given length. The noise values are 251 * scaled in order to yield a noise energy of 1.0 252 * \param spec pointer to were the noise values will be written to. 253 * \param size amount of noise values to be generated. 254 * \param pRandomState pointer to the state of the random generator being used. 255 * \return exponent of generated noise vector. 256 */ 257 static int GenerateRandomVector (FIXP_DBL *RESTRICT spec, 258 int size, 259 int *pRandomState) 260 { 261 int i, invNrg_e = 0, nrg_e = 0; 262 FIXP_DBL invNrg_m, nrg_m = FL2FXCONST_DBL(0.0f) ; 263 FIXP_DBL *RESTRICT ptr = spec; 264 int randomState = *pRandomState; 265 266 #define GEN_NOISE_NRG_SCALE 7 267 268 /* Generate noise and calculate energy. */ 269 for (i=0; i<size; i++) 270 { 271 randomState = (1664525L * randomState) + 1013904223L; // Numerical Recipes 272 nrg_m = fPow2AddDiv2(nrg_m, (FIXP_DBL)randomState>>GEN_NOISE_NRG_SCALE); 273 *ptr++ = (FIXP_DBL)randomState; 274 } 275 nrg_e = GEN_NOISE_NRG_SCALE*2 + 1; 276 277 /* weight noise with = 1 / sqrt_nrg; */ 278 invNrg_m = invSqrtNorm2(nrg_m<<1, &invNrg_e); 279 invNrg_e += -((nrg_e-1)>>1); 280 281 for (i=size; i--; ) 282 { 283 spec[i] = fMult(spec[i], invNrg_m); 284 } 285 286 /* Store random state */ 287 *pRandomState = randomState; 288 289 return invNrg_e; 290 } 291 292 static void ScaleBand (FIXP_DBL *RESTRICT spec, int size, int scaleFactor, int specScale, int noise_e, int out_of_phase) 293 { 294 int i, shift, sfExponent; 295 FIXP_DBL sfMatissa; 296 297 /* Get gain from scale factor value = 2^(scaleFactor * 0.25) */ 298 sfMatissa = MantissaTable[scaleFactor & 0x03][0]; 299 /* sfExponent = (scaleFactor >> 2) + ExponentTable[scaleFactor & 0x03][0]; */ 300 /* Note: ExponentTable[scaleFactor & 0x03][0] is always 1. */ 301 sfExponent = (scaleFactor >> 2) + 1; 302 303 if (out_of_phase != 0) { 304 sfMatissa = -sfMatissa; 305 } 306 307 /* +1 because of fMultDiv2 below. */ 308 shift = sfExponent - specScale + 1 + noise_e; 309 310 /* Apply gain to noise values */ 311 if (shift>=0) { 312 shift = fixMin( shift, DFRACT_BITS-1 ); 313 for (i = size ; i-- != 0; ) { 314 spec [i] = fMultDiv2 (spec [i], sfMatissa) << shift; 315 } 316 } else { 317 shift = fixMin( -shift, DFRACT_BITS-1 ); 318 for (i = size ; i-- != 0; ) { 319 spec [i] = fMultDiv2 (spec [i], sfMatissa) >> shift; 320 } 321 } 322 } 323 324 325 /*! 326 \brief Apply PNS 327 328 The function applies PNS (i.e. it generates noise) on the bands 329 flagged as noisy bands 330 331 */ 332 void CPns_Apply (const CPnsData *pPnsData, 333 const CIcsInfo *pIcsInfo, 334 SPECTRAL_PTR pSpectrum, 335 const SHORT *pSpecScale, 336 const SHORT *pScaleFactor, 337 const SamplingRateInfo *pSamplingRateInfo, 338 const INT granuleLength, 339 const int channel) 340 { 341 if (pPnsData->PnsActive) { 342 const short *BandOffsets = GetScaleFactorBandOffsets(pIcsInfo, pSamplingRateInfo); 343 344 int ScaleFactorBandsTransmitted = GetScaleFactorBandsTransmitted(pIcsInfo); 345 346 for (int window = 0, group = 0; group < GetWindowGroups(pIcsInfo); group++) { 347 for (int groupwin = 0; groupwin < GetWindowGroupLength(pIcsInfo, group); groupwin++, window++) { 348 FIXP_DBL *spectrum = SPEC(pSpectrum, window, granuleLength); 349 350 for (int band = 0 ; band < ScaleFactorBandsTransmitted; band++) { 351 if (CPns_IsPnsUsed (pPnsData, group, band)) { 352 UINT pns_band = group*16+band; 353 354 int bandWidth = BandOffsets [band + 1] - BandOffsets [band] ; 355 int noise_e; 356 357 FDK_ASSERT(bandWidth >= 0); 358 359 if (channel > 0 && CPns_IsCorrelated(pPnsData, group, band)) 360 { 361 noise_e = GenerateRandomVector (spectrum + BandOffsets [band], bandWidth, 362 &pPnsData->randomSeed [pns_band]) ; 363 } 364 else 365 { 366 pPnsData->randomSeed [pns_band] = *pPnsData->currentSeed ; 367 368 noise_e = GenerateRandomVector (spectrum + BandOffsets [band], bandWidth, 369 pPnsData->currentSeed) ; 370 } 371 372 int outOfPhase = CPns_IsOutOfPhase (pPnsData, group, band); 373 374 ScaleBand (spectrum + BandOffsets [band], bandWidth, 375 pScaleFactor[pns_band], 376 pSpecScale[window], noise_e, outOfPhase) ; 377 } 378 } 379 } 380 } 381 } 382 } 383
