1 2 /* ----------------------------------------------------------------------------------------------------------- 3 Software License for The Fraunhofer FDK AAC Codec Library for Android 4 5 Copyright 1995 - 2012 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): Christian Griebel 87 Description: Dynamic range control (DRC) decoder tool for SBR 88 89 ******************************************************************************/ 90 91 #include "sbrdec_drc.h" 92 93 94 /* DRC - Offset table for QMF interpolation. */ 95 static const int offsetTab[2][16] = 96 { 97 { 0, 4, 8, 12, 16, 20, 24, 28, 0, 0, 0, 0, 0, 0, 0, 0 }, /* 1024 framing */ 98 { 0, 4, 8, 12, 16, 19, 22, 26, 0, 0, 0, 0, 0, 0, 0, 0 } /* 960 framing */ 99 }; 100 101 /*! 102 \brief Initialize DRC QMF factors 103 104 \hDrcData Handle to DRC channel data. 105 106 \return none 107 */ 108 void sbrDecoder_drcInitChannel ( 109 HANDLE_SBR_DRC_CHANNEL hDrcData ) 110 { 111 int band; 112 113 if (hDrcData == NULL) { 114 return; 115 } 116 117 for (band = 0; band < (64); band++) { 118 hDrcData->prevFact_mag[band] = FL2FXCONST_DBL(0.5f); 119 } 120 121 for (band = 0; band < SBRDEC_MAX_DRC_BANDS; band++) { 122 hDrcData->currFact_mag[band] = FL2FXCONST_DBL(0.5f); 123 hDrcData->nextFact_mag[band] = FL2FXCONST_DBL(0.5f); 124 } 125 126 hDrcData->prevFact_exp = 1; 127 hDrcData->currFact_exp = 1; 128 hDrcData->nextFact_exp = 1; 129 130 hDrcData->numBandsCurr = 0; 131 hDrcData->numBandsNext = 0; 132 133 hDrcData->winSequenceCurr = 0; 134 hDrcData->winSequenceNext = 0; 135 136 hDrcData->drcInterpolationSchemeCurr = 0; 137 hDrcData->drcInterpolationSchemeNext = 0; 138 139 hDrcData->enable = 0; 140 } 141 142 143 /*! 144 \brief Swap DRC QMF scaling factors after they have been applied. 145 146 \hDrcData Handle to DRC channel data. 147 148 \return none 149 */ 150 void sbrDecoder_drcUpdateChannel ( 151 HANDLE_SBR_DRC_CHANNEL hDrcData ) 152 { 153 if (hDrcData == NULL) { 154 return; 155 } 156 if (hDrcData->enable != 1) { 157 return; 158 } 159 160 /* swap previous data */ 161 FDKmemcpy( hDrcData->currFact_mag, 162 hDrcData->nextFact_mag, 163 SBRDEC_MAX_DRC_BANDS * sizeof(FIXP_DBL) ); 164 165 hDrcData->currFact_exp = hDrcData->nextFact_exp; 166 167 hDrcData->numBandsCurr = hDrcData->numBandsNext; 168 169 FDKmemcpy( hDrcData->bandTopCurr, 170 hDrcData->bandTopNext, 171 SBRDEC_MAX_DRC_BANDS * sizeof(USHORT) ); 172 173 hDrcData->drcInterpolationSchemeCurr = hDrcData->drcInterpolationSchemeNext; 174 175 hDrcData->winSequenceCurr = hDrcData->winSequenceNext; 176 } 177 178 179 /*! 180 \brief Apply DRC factors slot based. 181 182 \hDrcData Handle to DRC channel data. 183 \qmfRealSlot Pointer to real valued QMF data of one time slot. 184 \qmfImagSlot Pointer to the imaginary QMF data of one time slot. 185 \col Number of the time slot. 186 \numQmfSubSamples Total number of time slots for one frame. 187 \scaleFactor Pointer to the out scale factor of the time slot. 188 189 \return None. 190 */ 191 void sbrDecoder_drcApplySlot ( 192 HANDLE_SBR_DRC_CHANNEL hDrcData, 193 FIXP_DBL *qmfRealSlot, 194 FIXP_DBL *qmfImagSlot, 195 int col, 196 int numQmfSubSamples, 197 int maxShift 198 ) 199 { 200 const int *offset; 201 202 int band, bottomMdct, topMdct, bin, useLP; 203 int indx = numQmfSubSamples - (numQmfSubSamples >> 1) - 10; /* l_border */ 204 int frameLenFlag = (numQmfSubSamples == 30) ? 1 : 0; 205 206 const FIXP_DBL *fact_mag = NULL; 207 INT fact_exp = 0; 208 UINT numBands = 0; 209 USHORT *bandTop = NULL; 210 int shortDrc = 0; 211 212 FIXP_DBL alphaValue = FL2FXCONST_DBL(0.0f); 213 214 if (hDrcData == NULL) { 215 return; 216 } 217 if (hDrcData->enable != 1) { 218 return; 219 } 220 221 offset = offsetTab[frameLenFlag]; 222 223 useLP = (qmfImagSlot == NULL) ? 1 : 0; 224 225 col += indx; 226 bottomMdct = 0; 227 bin = 0; 228 229 /* get respective data and calc interpolation factor */ 230 if (col < (numQmfSubSamples>>1)) { /* first half of current frame */ 231 if (hDrcData->winSequenceCurr != 2) { /* long window */ 232 int j = col + (numQmfSubSamples>>1); 233 234 if (hDrcData->drcInterpolationSchemeCurr == 0) { 235 INT k = (frameLenFlag) ? 0x4444444 : 0x4000000; 236 237 alphaValue = (FIXP_DBL)(j * k); 238 } 239 else { 240 if (j >= offset[hDrcData->drcInterpolationSchemeCurr - 1]) { 241 alphaValue = (FIXP_DBL)MAXVAL_DBL; 242 } 243 } 244 } 245 else { /* short windows */ 246 shortDrc = 1; 247 } 248 249 fact_mag = hDrcData->currFact_mag; 250 fact_exp = hDrcData->currFact_exp; 251 numBands = hDrcData->numBandsCurr; 252 bandTop = hDrcData->bandTopCurr; 253 } 254 else if (col < numQmfSubSamples) { /* second half of current frame */ 255 if (hDrcData->winSequenceNext != 2) { /* next: long window */ 256 int j = col - (numQmfSubSamples>>1); 257 258 if (hDrcData->drcInterpolationSchemeNext == 0) { 259 INT k = (frameLenFlag) ? 0x4444444 : 0x4000000; 260 261 alphaValue = (FIXP_DBL)(j * k); 262 } 263 else { 264 if (j >= offset[hDrcData->drcInterpolationSchemeNext - 1]) { 265 alphaValue = (FIXP_DBL)MAXVAL_DBL; 266 } 267 } 268 269 fact_mag = hDrcData->nextFact_mag; 270 fact_exp = hDrcData->nextFact_exp; 271 numBands = hDrcData->numBandsNext; 272 bandTop = hDrcData->bandTopNext; 273 } 274 else { /* next: short windows */ 275 if (hDrcData->winSequenceCurr != 2) { /* current: long window */ 276 alphaValue = (FIXP_DBL)0; 277 278 fact_mag = hDrcData->nextFact_mag; 279 fact_exp = hDrcData->nextFact_exp; 280 numBands = hDrcData->numBandsNext; 281 bandTop = hDrcData->bandTopNext; 282 } 283 else { /* current: short windows */ 284 shortDrc = 1; 285 286 fact_mag = hDrcData->currFact_mag; 287 fact_exp = hDrcData->currFact_exp; 288 numBands = hDrcData->numBandsCurr; 289 bandTop = hDrcData->bandTopCurr; 290 } 291 } 292 } 293 else { /* first half of next frame */ 294 if (hDrcData->winSequenceNext != 2) { /* long window */ 295 int j = col - (numQmfSubSamples>>1); 296 297 if (hDrcData->drcInterpolationSchemeNext == 0) { 298 INT k = (frameLenFlag) ? 0x4444444 : 0x4000000; 299 300 alphaValue = (FIXP_DBL)(j * k); 301 } 302 else { 303 if (j >= offset[hDrcData->drcInterpolationSchemeNext - 1]) { 304 alphaValue = (FIXP_DBL)MAXVAL_DBL; 305 } 306 } 307 } 308 else { /* short windows */ 309 shortDrc = 1; 310 } 311 312 fact_mag = hDrcData->nextFact_mag; 313 fact_exp = hDrcData->nextFact_exp; 314 numBands = hDrcData->numBandsNext; 315 bandTop = hDrcData->bandTopNext; 316 317 col -= numQmfSubSamples; 318 } 319 320 321 /* process bands */ 322 for (band = 0; band < (int)numBands; band++) { 323 int bottomQmf, topQmf; 324 325 FIXP_DBL drcFact_mag = (FIXP_DBL)MAXVAL_DBL; 326 327 topMdct = (bandTop[band]+1) << 2; 328 329 if (!shortDrc) { /* long window */ 330 if (frameLenFlag) { 331 /* 960 framing */ 332 bottomMdct = 30 * (bottomMdct / 30); 333 topMdct = 30 * (topMdct / 30); 334 335 bottomQmf = fMultIfloor((FIXP_DBL)0x4444444, bottomMdct); 336 topQmf = fMultIfloor((FIXP_DBL)0x4444444, topMdct); 337 } 338 else { 339 /* 1024 framing */ 340 bottomMdct &= ~0x1f; 341 topMdct &= ~0x1f; 342 343 bottomQmf = bottomMdct >> 5; 344 topQmf = topMdct >> 5; 345 } 346 347 if (band == ((int)numBands-1)) { 348 topQmf = (64); 349 } 350 351 for (bin = bottomQmf; bin < topQmf; bin++) { 352 FIXP_DBL drcFact1_mag = hDrcData->prevFact_mag[bin]; 353 FIXP_DBL drcFact2_mag = fact_mag[band]; 354 355 /* normalize scale factors */ 356 if (hDrcData->prevFact_exp < maxShift) { 357 drcFact1_mag >>= maxShift - hDrcData->prevFact_exp; 358 } 359 if (fact_exp < maxShift) { 360 drcFact2_mag >>= maxShift - fact_exp; 361 } 362 363 /* interpolate */ 364 if (alphaValue == (FIXP_DBL)0) { 365 drcFact_mag = drcFact1_mag; 366 } else if (alphaValue == (FIXP_DBL)MAXVAL_DBL) { 367 drcFact_mag = drcFact2_mag; 368 } else { 369 drcFact_mag = fMult(alphaValue, drcFact2_mag) + fMult(((FIXP_DBL)MAXVAL_DBL - alphaValue), drcFact1_mag); 370 } 371 372 /* apply scaling */ 373 qmfRealSlot[bin] = fMult(qmfRealSlot[bin], drcFact_mag); 374 if (!useLP) { 375 qmfImagSlot[bin] = fMult(qmfImagSlot[bin], drcFact_mag); 376 } 377 378 /* save previous factors */ 379 if (col == (numQmfSubSamples>>1)-1) { 380 hDrcData->prevFact_mag[bin] = fact_mag[band]; 381 } 382 } 383 } 384 else { /* short windows */ 385 int startSample, stopSample; 386 FIXP_DBL invFrameSizeDiv8 = (frameLenFlag) ? (FIXP_DBL)0x1111111 : (FIXP_DBL)0x1000000; 387 388 if (frameLenFlag) { 389 /* 960 framing */ 390 bottomMdct = 30/8 * (bottomMdct*8/30); 391 topMdct = 30/8 * (topMdct*8/30); 392 } 393 else { 394 /* 1024 framing */ 395 bottomMdct &= ~0x03; 396 topMdct &= ~0x03; 397 } 398 399 /* startSample is truncated to the nearest corresponding start subsample in 400 the QMF of the short window bottom is present in:*/ 401 startSample = ((fMultIfloor( invFrameSizeDiv8, bottomMdct ) & 0x7) * numQmfSubSamples) >> 3; 402 403 /* stopSample is rounded upwards to the nearest corresponding stop subsample 404 in the QMF of the short window top is present in. */ 405 stopSample = ((fMultIceil( invFrameSizeDiv8, topMdct ) & 0xf) * numQmfSubSamples) >> 3; 406 407 bottomQmf = fMultIfloor( invFrameSizeDiv8, ((bottomMdct%(numQmfSubSamples<<2)) << 5) ); 408 topQmf = fMultIfloor( invFrameSizeDiv8, ((topMdct%(numQmfSubSamples<<2)) << 5) ); 409 410 /* extend last band */ 411 if (band == ((int)numBands-1)) { 412 topQmf = (64); 413 stopSample = numQmfSubSamples; 414 } 415 416 if (topQmf == 0) { 417 topQmf = (64); 418 } 419 420 /* save previous factors */ 421 if (stopSample == numQmfSubSamples) { 422 int tmpBottom = bottomQmf; 423 424 if (((numQmfSubSamples-1) & ~0x03) > startSample) { 425 tmpBottom = 0; /* band starts in previous short window */ 426 } 427 428 for (bin = tmpBottom; bin < topQmf; bin++) { 429 hDrcData->prevFact_mag[bin] = fact_mag[band]; 430 } 431 } 432 433 /* apply */ 434 if ((col >= startSample) && (col < stopSample)) { 435 if ((col & ~0x03) > startSample) { 436 bottomQmf = 0; /* band starts in previous short window */ 437 } 438 if (col < ((stopSample-1) & ~0x03)) { 439 topQmf = (64); /* band ends in next short window */ 440 } 441 442 drcFact_mag = fact_mag[band]; 443 444 /* normalize scale factor */ 445 if (fact_exp < maxShift) { 446 drcFact_mag >>= maxShift - fact_exp; 447 } 448 449 /* apply scaling */ 450 for (bin = bottomQmf; bin < topQmf; bin++) { 451 qmfRealSlot[bin] = fMult(qmfRealSlot[bin], drcFact_mag); 452 if (!useLP) { 453 qmfImagSlot[bin] = fMult(qmfImagSlot[bin], drcFact_mag); 454 } 455 } 456 } 457 } 458 459 bottomMdct = topMdct; 460 } /* end of bands loop */ 461 462 if (col == (numQmfSubSamples>>1)-1) { 463 hDrcData->prevFact_exp = fact_exp; 464 } 465 } 466 467 468 /*! 469 \brief Apply DRC factors frame based. 470 471 \hDrcData Handle to DRC channel data. 472 \qmfRealSlot Pointer to real valued QMF data of the whole frame. 473 \qmfImagSlot Pointer to the imaginary QMF data of the whole frame. 474 \numQmfSubSamples Total number of time slots for one frame. 475 \scaleFactor Pointer to the out scale factor of the frame. 476 477 \return None. 478 */ 479 void sbrDecoder_drcApply ( 480 HANDLE_SBR_DRC_CHANNEL hDrcData, 481 FIXP_DBL **QmfBufferReal, 482 FIXP_DBL **QmfBufferImag, 483 int numQmfSubSamples, 484 int *scaleFactor 485 ) 486 { 487 int col; 488 int maxShift = 0; 489 490 if (hDrcData == NULL) { 491 return; 492 } 493 if ( (hDrcData->enable == 0) 494 || ((hDrcData->numBandsCurr == 0) && (hDrcData->numBandsNext == 0)) 495 ) { 496 return; /* Avoid changing the scaleFactor even though the processing is disabled. */ 497 } 498 499 /* get max scale factor */ 500 if (hDrcData->prevFact_exp > maxShift) { 501 maxShift = hDrcData->prevFact_exp; 502 } 503 if (hDrcData->currFact_exp > maxShift) { 504 maxShift = hDrcData->currFact_exp; 505 } 506 if (hDrcData->nextFact_exp > maxShift) { 507 maxShift = hDrcData->nextFact_exp; 508 } 509 510 for (col = 0; col < numQmfSubSamples; col++) 511 { 512 FIXP_DBL *qmfSlotReal = QmfBufferReal[col]; 513 FIXP_DBL *qmfSlotImag = (QmfBufferImag == NULL) ? NULL : QmfBufferImag[col]; 514 515 sbrDecoder_drcApplySlot ( 516 hDrcData, 517 qmfSlotReal, 518 qmfSlotImag, 519 col, 520 numQmfSubSamples, 521 maxShift 522 ); 523 } 524 525 *scaleFactor += maxShift; 526 } 527 528
