1 /* ----------------------------------------------------------------------------- 2 Software License for The Fraunhofer FDK AAC Codec Library for Android 3 4 Copyright 1995 - 2018 Fraunhofer-Gesellschaft zur Frderung der angewandten 5 Forschung e.V. All rights reserved. 6 7 1. INTRODUCTION 8 The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software 9 that implements the MPEG Advanced Audio Coding ("AAC") encoding and decoding 10 scheme for digital audio. This FDK AAC Codec software is intended to be used on 11 a wide variety of Android devices. 12 13 AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient 14 general perceptual audio codecs. AAC-ELD is considered the best-performing 15 full-bandwidth communications codec by independent studies and is widely 16 deployed. AAC has been standardized by ISO and IEC as part of the MPEG 17 specifications. 18 19 Patent licenses for necessary patent claims for the FDK AAC Codec (including 20 those of Fraunhofer) may be obtained through Via Licensing 21 (www.vialicensing.com) or through the respective patent owners individually for 22 the purpose of encoding or decoding bit streams in products that are compliant 23 with the ISO/IEC MPEG audio standards. Please note that most manufacturers of 24 Android devices already license these patent claims through Via Licensing or 25 directly from the patent owners, and therefore FDK AAC Codec software may 26 already be covered under those patent licenses when it is used for those 27 licensed purposes only. 28 29 Commercially-licensed AAC software libraries, including floating-point versions 30 with enhanced sound quality, are also available from Fraunhofer. Users are 31 encouraged to check the Fraunhofer website for additional applications 32 information and documentation. 33 34 2. COPYRIGHT LICENSE 35 36 Redistribution and use in source and binary forms, with or without modification, 37 are permitted without payment of copyright license fees provided that you 38 satisfy the following conditions: 39 40 You must retain the complete text of this software license in redistributions of 41 the FDK AAC Codec or your modifications thereto in source code form. 42 43 You must retain the complete text of this software license in the documentation 44 and/or other materials provided with redistributions of the FDK AAC Codec or 45 your modifications thereto in binary form. You must make available free of 46 charge copies of the complete source code of the FDK AAC Codec and your 47 modifications thereto to recipients of copies in binary form. 48 49 The name of Fraunhofer may not be used to endorse or promote products derived 50 from this library without prior written permission. 51 52 You may not charge copyright license fees for anyone to use, copy or distribute 53 the FDK AAC Codec software or your modifications thereto. 54 55 Your modified versions of the FDK AAC Codec must carry prominent notices stating 56 that you changed the software and the date of any change. For modified versions 57 of the FDK AAC Codec, the term "Fraunhofer FDK AAC Codec Library for Android" 58 must be replaced by the term "Third-Party Modified Version of the Fraunhofer FDK 59 AAC Codec Library for Android." 60 61 3. NO PATENT LICENSE 62 63 NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without 64 limitation the patents of Fraunhofer, ARE GRANTED BY THIS SOFTWARE LICENSE. 65 Fraunhofer provides no warranty of patent non-infringement with respect to this 66 software. 67 68 You may use this FDK AAC Codec software or modifications thereto only for 69 purposes that are authorized by appropriate patent licenses. 70 71 4. DISCLAIMER 72 73 This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright 74 holders and contributors "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, 75 including but not limited to the implied warranties of merchantability and 76 fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 77 CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, 78 or consequential damages, including but not limited to procurement of substitute 79 goods or services; loss of use, data, or profits, or business interruption, 80 however caused and on any theory of liability, whether in contract, strict 81 liability, or tort (including negligence), arising in any way out of the use of 82 this software, even if advised of the possibility of such damage. 83 84 5. CONTACT INFORMATION 85 86 Fraunhofer Institute for Integrated Circuits IIS 87 Attention: Audio and Multimedia Departments - FDK AAC LL 88 Am Wolfsmantel 33 89 91058 Erlangen, Germany 90 91 www.iis.fraunhofer.de/amm 92 amm-info (at) iis.fraunhofer.de 93 ----------------------------------------------------------------------------- */ 94 95 /**************************** AAC encoder library ****************************** 96 97 Author(s): M. Werner, Tobias Chalupka 98 99 Description: Block switching 100 101 *******************************************************************************/ 102 103 /****************** Includes *****************************/ 104 105 #include "block_switch.h" 106 #include "genericStds.h" 107 108 #define LOWOV_WINDOW _LOWOV_WINDOW 109 110 /**************** internal function prototypes ***********/ 111 112 static FIXP_DBL FDKaacEnc_GetWindowEnergy(const FIXP_DBL in[], 113 const INT blSwWndIdx); 114 115 static void FDKaacEnc_CalcWindowEnergy( 116 BLOCK_SWITCHING_CONTROL *RESTRICT blockSwitchingControl, INT windowLen, 117 const INT_PCM *pTimeSignal); 118 119 /****************** Constants *****************************/ 120 /* LONG START 121 * SHORT STOP LOWOV */ 122 static const INT blockType2windowShape[2][5] = { 123 {SINE_WINDOW, KBD_WINDOW, WRONG_WINDOW, SINE_WINDOW, KBD_WINDOW}, /* LD */ 124 {KBD_WINDOW, SINE_WINDOW, SINE_WINDOW, KBD_WINDOW, WRONG_WINDOW}}; /* LC */ 125 126 /* IIR high pass coeffs */ 127 128 #ifndef SINETABLE_16BIT 129 130 static const FIXP_DBL hiPassCoeff[BLOCK_SWITCHING_IIR_LEN] = { 131 FL2FXCONST_DBL(-0.5095), FL2FXCONST_DBL(0.7548)}; 132 133 static const FIXP_DBL accWindowNrgFac = 134 FL2FXCONST_DBL(0.3f); /* factor for accumulating filtered window energies */ 135 static const FIXP_DBL oneMinusAccWindowNrgFac = FL2FXCONST_DBL(0.7f); 136 /* static const float attackRatio = 10.0; */ /* lower ratio limit for attacks */ 137 static const FIXP_DBL invAttackRatio = 138 FL2FXCONST_DBL(0.1f); /* inverted lower ratio limit for attacks */ 139 140 /* The next constants are scaled, because they are used for comparison with 141 * scaled values*/ 142 /* minimum energy for attacks */ 143 static const FIXP_DBL minAttackNrg = 144 (FL2FXCONST_DBL(1e+6f * NORM_PCM_ENERGY) >> 145 BLOCK_SWITCH_ENERGY_SHIFT); /* minimum energy for attacks */ 146 147 #else 148 149 static const FIXP_SGL hiPassCoeff[BLOCK_SWITCHING_IIR_LEN] = { 150 FL2FXCONST_SGL(-0.5095), FL2FXCONST_SGL(0.7548)}; 151 152 static const FIXP_DBL accWindowNrgFac = 153 FL2FXCONST_DBL(0.3f); /* factor for accumulating filtered window energies */ 154 static const FIXP_SGL oneMinusAccWindowNrgFac = FL2FXCONST_SGL(0.7f); 155 /* static const float attackRatio = 10.0; */ /* lower ratio limit for attacks */ 156 static const FIXP_SGL invAttackRatio = 157 FL2FXCONST_SGL(0.1f); /* inverted lower ratio limit for attacks */ 158 /* minimum energy for attacks */ 159 static const FIXP_DBL minAttackNrg = 160 (FL2FXCONST_DBL(1e+6f * NORM_PCM_ENERGY) >> 161 BLOCK_SWITCH_ENERGY_SHIFT); /* minimum energy for attacks */ 162 163 #endif 164 165 /**************** internal function prototypes ***********/ 166 167 /****************** Routines ****************************/ 168 void FDKaacEnc_InitBlockSwitching( 169 BLOCK_SWITCHING_CONTROL *blockSwitchingControl, INT isLowDelay) { 170 FDKmemclear(blockSwitchingControl, sizeof(BLOCK_SWITCHING_CONTROL)); 171 172 if (isLowDelay) { 173 blockSwitchingControl->nBlockSwitchWindows = 4; 174 blockSwitchingControl->allowShortFrames = 0; 175 blockSwitchingControl->allowLookAhead = 0; 176 } else { 177 blockSwitchingControl->nBlockSwitchWindows = 8; 178 blockSwitchingControl->allowShortFrames = 1; 179 blockSwitchingControl->allowLookAhead = 1; 180 } 181 182 blockSwitchingControl->noOfGroups = MAX_NO_OF_GROUPS; 183 184 /* Initialize startvalue for blocktype */ 185 blockSwitchingControl->lastWindowSequence = LONG_WINDOW; 186 blockSwitchingControl->windowShape = 187 blockType2windowShape[blockSwitchingControl->allowShortFrames] 188 [blockSwitchingControl->lastWindowSequence]; 189 } 190 191 static const INT suggestedGroupingTable[TRANS_FAC][MAX_NO_OF_GROUPS] = { 192 /* Attack in Window 0 */ {1, 3, 3, 1}, 193 /* Attack in Window 1 */ {1, 1, 3, 3}, 194 /* Attack in Window 2 */ {2, 1, 3, 2}, 195 /* Attack in Window 3 */ {3, 1, 3, 1}, 196 /* Attack in Window 4 */ {3, 1, 1, 3}, 197 /* Attack in Window 5 */ {3, 2, 1, 2}, 198 /* Attack in Window 6 */ {3, 3, 1, 1}, 199 /* Attack in Window 7 */ {3, 3, 1, 1}}; 200 201 /* change block type depending on current blocktype and whether there's an 202 * attack */ 203 /* assume no look-ahead */ 204 static const INT chgWndSq[2][N_BLOCKTYPES] = { 205 /* LONG WINDOW START_WINDOW SHORT_WINDOW STOP_WINDOW, 206 LOWOV_WINDOW, WRONG_WINDOW */ 207 /*no attack*/ {LONG_WINDOW, STOP_WINDOW, WRONG_WINDOW, LONG_WINDOW, 208 STOP_WINDOW, WRONG_WINDOW}, 209 /*attack */ {START_WINDOW, LOWOV_WINDOW, WRONG_WINDOW, START_WINDOW, 210 LOWOV_WINDOW, WRONG_WINDOW}}; 211 212 /* change block type depending on current blocktype and whether there's an 213 * attack */ 214 /* assume look-ahead */ 215 static const INT chgWndSqLkAhd[2][2][N_BLOCKTYPES] = { 216 /*attack LONG WINDOW START_WINDOW SHORT_WINDOW STOP_WINDOW LOWOV_WINDOW, WRONG_WINDOW */ /* last attack */ 217 /*no attack*/ { 218 {LONG_WINDOW, SHORT_WINDOW, STOP_WINDOW, LONG_WINDOW, WRONG_WINDOW, 219 WRONG_WINDOW}, /* no attack */ 220 /*attack */ {START_WINDOW, SHORT_WINDOW, SHORT_WINDOW, START_WINDOW, 221 WRONG_WINDOW, WRONG_WINDOW}}, /* no attack */ 222 /*no attack*/ {{LONG_WINDOW, SHORT_WINDOW, SHORT_WINDOW, LONG_WINDOW, 223 WRONG_WINDOW, WRONG_WINDOW}, /* attack */ 224 /*attack */ {START_WINDOW, SHORT_WINDOW, SHORT_WINDOW, 225 START_WINDOW, WRONG_WINDOW, 226 WRONG_WINDOW}} /* attack */ 227 }; 228 229 int FDKaacEnc_BlockSwitching(BLOCK_SWITCHING_CONTROL *blockSwitchingControl, 230 const INT granuleLength, const int isLFE, 231 const INT_PCM *pTimeSignal) { 232 UINT i; 233 FIXP_DBL enM1, enMax; 234 235 UINT nBlockSwitchWindows = blockSwitchingControl->nBlockSwitchWindows; 236 237 /* for LFE : only LONG window allowed */ 238 if (isLFE) { 239 /* case LFE: */ 240 /* only long blocks, always use sine windows (MPEG2 AAC, MPEG4 AAC) */ 241 blockSwitchingControl->lastWindowSequence = LONG_WINDOW; 242 blockSwitchingControl->windowShape = SINE_WINDOW; 243 blockSwitchingControl->noOfGroups = 1; 244 blockSwitchingControl->groupLen[0] = 1; 245 246 return (0); 247 }; 248 249 /* Save current attack index as last attack index */ 250 blockSwitchingControl->lastattack = blockSwitchingControl->attack; 251 blockSwitchingControl->lastAttackIndex = blockSwitchingControl->attackIndex; 252 253 /* Save current window energy as last window energy */ 254 FDKmemcpy(blockSwitchingControl->windowNrg[0], 255 blockSwitchingControl->windowNrg[1], 256 sizeof(blockSwitchingControl->windowNrg[0])); 257 FDKmemcpy(blockSwitchingControl->windowNrgF[0], 258 blockSwitchingControl->windowNrgF[1], 259 sizeof(blockSwitchingControl->windowNrgF[0])); 260 261 if (blockSwitchingControl->allowShortFrames) { 262 /* Calculate suggested grouping info for the last frame */ 263 264 /* Reset grouping info */ 265 FDKmemclear(blockSwitchingControl->groupLen, 266 sizeof(blockSwitchingControl->groupLen)); 267 268 /* Set grouping info */ 269 blockSwitchingControl->noOfGroups = MAX_NO_OF_GROUPS; 270 271 FDKmemcpy(blockSwitchingControl->groupLen, 272 suggestedGroupingTable[blockSwitchingControl->lastAttackIndex], 273 sizeof(blockSwitchingControl->groupLen)); 274 275 if (blockSwitchingControl->attack == TRUE) 276 blockSwitchingControl->maxWindowNrg = 277 FDKaacEnc_GetWindowEnergy(blockSwitchingControl->windowNrg[0], 278 blockSwitchingControl->lastAttackIndex); 279 else 280 blockSwitchingControl->maxWindowNrg = FL2FXCONST_DBL(0.0); 281 } 282 283 /* Calculate unfiltered and filtered energies in subwindows and combine to 284 * segments */ 285 FDKaacEnc_CalcWindowEnergy( 286 blockSwitchingControl, 287 granuleLength >> (nBlockSwitchWindows == 4 ? 2 : 3), pTimeSignal); 288 289 /* now calculate if there is an attack */ 290 291 /* reset attack */ 292 blockSwitchingControl->attack = FALSE; 293 294 /* look for attack */ 295 enMax = FL2FXCONST_DBL(0.0f); 296 enM1 = blockSwitchingControl->windowNrgF[0][nBlockSwitchWindows - 1]; 297 298 for (i = 0; i < nBlockSwitchWindows; i++) { 299 FIXP_DBL tmp = 300 fMultDiv2(oneMinusAccWindowNrgFac, blockSwitchingControl->accWindowNrg); 301 blockSwitchingControl->accWindowNrg = fMultAdd(tmp, accWindowNrgFac, enM1); 302 303 if (fMult(blockSwitchingControl->windowNrgF[1][i], invAttackRatio) > 304 blockSwitchingControl->accWindowNrg) { 305 blockSwitchingControl->attack = TRUE; 306 blockSwitchingControl->attackIndex = i; 307 } 308 enM1 = blockSwitchingControl->windowNrgF[1][i]; 309 enMax = fixMax(enMax, enM1); 310 } 311 312 if (enMax < minAttackNrg) blockSwitchingControl->attack = FALSE; 313 314 /* Check if attack spreads over frame border */ 315 if ((blockSwitchingControl->attack == FALSE) && 316 (blockSwitchingControl->lastattack == TRUE)) { 317 /* if attack is in last window repeat SHORT_WINDOW */ 318 if (((blockSwitchingControl->windowNrgF[0][nBlockSwitchWindows - 1] >> 4) > 319 fMult((FIXP_DBL)(10 << (DFRACT_BITS - 1 - 4)), 320 blockSwitchingControl->windowNrgF[1][1])) && 321 (blockSwitchingControl->lastAttackIndex == 322 (INT)nBlockSwitchWindows - 1)) { 323 blockSwitchingControl->attack = TRUE; 324 blockSwitchingControl->attackIndex = 0; 325 } 326 } 327 328 if (blockSwitchingControl->allowLookAhead) { 329 blockSwitchingControl->lastWindowSequence = 330 chgWndSqLkAhd[blockSwitchingControl->lastattack] 331 [blockSwitchingControl->attack] 332 [blockSwitchingControl->lastWindowSequence]; 333 } else { 334 /* Low Delay */ 335 blockSwitchingControl->lastWindowSequence = 336 chgWndSq[blockSwitchingControl->attack] 337 [blockSwitchingControl->lastWindowSequence]; 338 } 339 340 /* update window shape */ 341 blockSwitchingControl->windowShape = 342 blockType2windowShape[blockSwitchingControl->allowShortFrames] 343 [blockSwitchingControl->lastWindowSequence]; 344 345 return (0); 346 } 347 348 static FIXP_DBL FDKaacEnc_GetWindowEnergy(const FIXP_DBL in[], 349 const INT blSwWndIdx) { 350 /* For coherency, change FDKaacEnc_GetWindowEnergy() to calcluate the energy 351 for a block switching analysis windows, not for a short block. The same is 352 done FDKaacEnc_CalcWindowEnergy(). The result of 353 FDKaacEnc_GetWindowEnergy() is used for a comparision of the max energy of 354 left/right channel. */ 355 356 return in[blSwWndIdx]; 357 } 358 359 static void FDKaacEnc_CalcWindowEnergy( 360 BLOCK_SWITCHING_CONTROL *RESTRICT blockSwitchingControl, INT windowLen, 361 const INT_PCM *pTimeSignal) { 362 INT i; 363 UINT w; 364 365 #ifndef SINETABLE_16BIT 366 const FIXP_DBL hiPassCoeff0 = hiPassCoeff[0]; 367 const FIXP_DBL hiPassCoeff1 = hiPassCoeff[1]; 368 #else 369 const FIXP_SGL hiPassCoeff0 = hiPassCoeff[0]; 370 const FIXP_SGL hiPassCoeff1 = hiPassCoeff[1]; 371 #endif 372 373 FIXP_DBL temp_iirState0 = blockSwitchingControl->iirStates[0]; 374 FIXP_DBL temp_iirState1 = blockSwitchingControl->iirStates[1]; 375 376 /* sum up scalarproduct of timesignal as windowed Energies */ 377 for (w = 0; w < blockSwitchingControl->nBlockSwitchWindows; w++) { 378 ULONG temp_windowNrg = 0x0; 379 ULONG temp_windowNrgF = 0x0; 380 381 /* windowNrg = sum(timesample^2) */ 382 for (i = 0; i < windowLen; i++) { 383 FIXP_DBL tempUnfiltered, t1, t2; 384 /* tempUnfiltered is scaled with 1 to prevent overflows during calculation 385 * of tempFiltred */ 386 #if SAMPLE_BITS == DFRACT_BITS 387 tempUnfiltered = (FIXP_DBL)*pTimeSignal++ >> 1; 388 #else 389 tempUnfiltered = (FIXP_DBL)*pTimeSignal++ 390 << (DFRACT_BITS - SAMPLE_BITS - 1); 391 #endif 392 t1 = fMultDiv2(hiPassCoeff1, tempUnfiltered - temp_iirState0); 393 t2 = fMultDiv2(hiPassCoeff0, temp_iirState1); 394 temp_iirState0 = tempUnfiltered; 395 temp_iirState1 = (t1 - t2) << 1; 396 397 temp_windowNrg += (LONG)fPow2Div2(temp_iirState0) >> 398 (BLOCK_SWITCH_ENERGY_SHIFT - 1 - 2); 399 temp_windowNrgF += (LONG)fPow2Div2(temp_iirState1) >> 400 (BLOCK_SWITCH_ENERGY_SHIFT - 1 - 2); 401 } 402 blockSwitchingControl->windowNrg[1][w] = 403 (LONG)fMin(temp_windowNrg, (UINT)MAXVAL_DBL); 404 blockSwitchingControl->windowNrgF[1][w] = 405 (LONG)fMin(temp_windowNrgF, (UINT)MAXVAL_DBL); 406 } 407 blockSwitchingControl->iirStates[0] = temp_iirState0; 408 blockSwitchingControl->iirStates[1] = temp_iirState1; 409 } 410 411 static const UCHAR synchronizedBlockTypeTable[5][5] = { 412 /* LONG_WINDOW START_WINDOW SHORT_WINDOW STOP_WINDOW 413 LOWOV_WINDOW*/ 414 /* LONG_WINDOW */ {LONG_WINDOW, START_WINDOW, SHORT_WINDOW, STOP_WINDOW, 415 LOWOV_WINDOW}, 416 /* START_WINDOW */ 417 {START_WINDOW, START_WINDOW, SHORT_WINDOW, SHORT_WINDOW, LOWOV_WINDOW}, 418 /* SHORT_WINDOW */ 419 {SHORT_WINDOW, SHORT_WINDOW, SHORT_WINDOW, SHORT_WINDOW, WRONG_WINDOW}, 420 /* STOP_WINDOW */ 421 {STOP_WINDOW, SHORT_WINDOW, SHORT_WINDOW, STOP_WINDOW, LOWOV_WINDOW}, 422 /* LOWOV_WINDOW */ 423 {LOWOV_WINDOW, LOWOV_WINDOW, WRONG_WINDOW, LOWOV_WINDOW, LOWOV_WINDOW}, 424 }; 425 426 int FDKaacEnc_SyncBlockSwitching( 427 BLOCK_SWITCHING_CONTROL *blockSwitchingControlLeft, 428 BLOCK_SWITCHING_CONTROL *blockSwitchingControlRight, const INT nChannels, 429 const INT commonWindow) { 430 UCHAR patchType = LONG_WINDOW; 431 432 if (nChannels == 2 && commonWindow == TRUE) { 433 /* could be better with a channel loop (need a handle to psy_data) */ 434 /* get suggested Block Types and synchronize */ 435 patchType = synchronizedBlockTypeTable[patchType][blockSwitchingControlLeft 436 ->lastWindowSequence]; 437 patchType = synchronizedBlockTypeTable[patchType][blockSwitchingControlRight 438 ->lastWindowSequence]; 439 440 /* sanity check (no change from low overlap window to short winow and vice 441 * versa) */ 442 if (patchType == WRONG_WINDOW) return -1; /* mixed up AAC-LC and AAC-LD */ 443 444 /* Set synchronized Blocktype */ 445 blockSwitchingControlLeft->lastWindowSequence = patchType; 446 blockSwitchingControlRight->lastWindowSequence = patchType; 447 448 /* update window shape */ 449 blockSwitchingControlLeft->windowShape = 450 blockType2windowShape[blockSwitchingControlLeft->allowShortFrames] 451 [blockSwitchingControlLeft->lastWindowSequence]; 452 blockSwitchingControlRight->windowShape = 453 blockType2windowShape[blockSwitchingControlLeft->allowShortFrames] 454 [blockSwitchingControlRight->lastWindowSequence]; 455 } 456 457 if (blockSwitchingControlLeft->allowShortFrames) { 458 int i; 459 460 if (nChannels == 2) { 461 if (commonWindow == TRUE) { 462 /* Synchronize grouping info */ 463 int windowSequenceLeftOld = 464 blockSwitchingControlLeft->lastWindowSequence; 465 int windowSequenceRightOld = 466 blockSwitchingControlRight->lastWindowSequence; 467 468 /* Long Blocks */ 469 if (patchType != SHORT_WINDOW) { 470 /* Set grouping info */ 471 blockSwitchingControlLeft->noOfGroups = 1; 472 blockSwitchingControlRight->noOfGroups = 1; 473 blockSwitchingControlLeft->groupLen[0] = 1; 474 blockSwitchingControlRight->groupLen[0] = 1; 475 476 for (i = 1; i < MAX_NO_OF_GROUPS; i++) { 477 blockSwitchingControlLeft->groupLen[i] = 0; 478 blockSwitchingControlRight->groupLen[i] = 0; 479 } 480 } 481 482 /* Short Blocks */ 483 else { 484 /* in case all two channels were detected as short-blocks before 485 * syncing, use the grouping of channel with higher maxWindowNrg */ 486 if ((windowSequenceLeftOld == SHORT_WINDOW) && 487 (windowSequenceRightOld == SHORT_WINDOW)) { 488 if (blockSwitchingControlLeft->maxWindowNrg > 489 blockSwitchingControlRight->maxWindowNrg) { 490 /* Left Channel wins */ 491 blockSwitchingControlRight->noOfGroups = 492 blockSwitchingControlLeft->noOfGroups; 493 for (i = 0; i < MAX_NO_OF_GROUPS; i++) { 494 blockSwitchingControlRight->groupLen[i] = 495 blockSwitchingControlLeft->groupLen[i]; 496 } 497 } else { 498 /* Right Channel wins */ 499 blockSwitchingControlLeft->noOfGroups = 500 blockSwitchingControlRight->noOfGroups; 501 for (i = 0; i < MAX_NO_OF_GROUPS; i++) { 502 blockSwitchingControlLeft->groupLen[i] = 503 blockSwitchingControlRight->groupLen[i]; 504 } 505 } 506 } else if ((windowSequenceLeftOld == SHORT_WINDOW) && 507 (windowSequenceRightOld != SHORT_WINDOW)) { 508 /* else use grouping of short-block channel */ 509 blockSwitchingControlRight->noOfGroups = 510 blockSwitchingControlLeft->noOfGroups; 511 for (i = 0; i < MAX_NO_OF_GROUPS; i++) { 512 blockSwitchingControlRight->groupLen[i] = 513 blockSwitchingControlLeft->groupLen[i]; 514 } 515 } else if ((windowSequenceRightOld == SHORT_WINDOW) && 516 (windowSequenceLeftOld != SHORT_WINDOW)) { 517 blockSwitchingControlLeft->noOfGroups = 518 blockSwitchingControlRight->noOfGroups; 519 for (i = 0; i < MAX_NO_OF_GROUPS; i++) { 520 blockSwitchingControlLeft->groupLen[i] = 521 blockSwitchingControlRight->groupLen[i]; 522 } 523 } else { 524 /* syncing a start and stop window ... */ 525 blockSwitchingControlLeft->noOfGroups = 526 blockSwitchingControlRight->noOfGroups = 2; 527 blockSwitchingControlLeft->groupLen[0] = 528 blockSwitchingControlRight->groupLen[0] = 4; 529 blockSwitchingControlLeft->groupLen[1] = 530 blockSwitchingControlRight->groupLen[1] = 4; 531 } 532 } /* Short Blocks */ 533 } else { 534 /* stereo, no common window */ 535 if (blockSwitchingControlLeft->lastWindowSequence != SHORT_WINDOW) { 536 blockSwitchingControlLeft->noOfGroups = 1; 537 blockSwitchingControlLeft->groupLen[0] = 1; 538 for (i = 1; i < MAX_NO_OF_GROUPS; i++) { 539 blockSwitchingControlLeft->groupLen[i] = 0; 540 } 541 } 542 if (blockSwitchingControlRight->lastWindowSequence != SHORT_WINDOW) { 543 blockSwitchingControlRight->noOfGroups = 1; 544 blockSwitchingControlRight->groupLen[0] = 1; 545 for (i = 1; i < MAX_NO_OF_GROUPS; i++) { 546 blockSwitchingControlRight->groupLen[i] = 0; 547 } 548 } 549 } /* common window */ 550 } else { 551 /* Mono */ 552 if (blockSwitchingControlLeft->lastWindowSequence != SHORT_WINDOW) { 553 blockSwitchingControlLeft->noOfGroups = 1; 554 blockSwitchingControlLeft->groupLen[0] = 1; 555 556 for (i = 1; i < MAX_NO_OF_GROUPS; i++) { 557 blockSwitchingControlLeft->groupLen[i] = 0; 558 } 559 } 560 } 561 } /* allowShortFrames */ 562 563 /* Translate LOWOV_WINDOW block type to a meaningful window shape. */ 564 if (!blockSwitchingControlLeft->allowShortFrames) { 565 if (blockSwitchingControlLeft->lastWindowSequence != LONG_WINDOW && 566 blockSwitchingControlLeft->lastWindowSequence != STOP_WINDOW) { 567 blockSwitchingControlLeft->lastWindowSequence = LONG_WINDOW; 568 blockSwitchingControlLeft->windowShape = LOL_WINDOW; 569 } 570 } 571 if (nChannels == 2) { 572 if (!blockSwitchingControlRight->allowShortFrames) { 573 if (blockSwitchingControlRight->lastWindowSequence != LONG_WINDOW && 574 blockSwitchingControlRight->lastWindowSequence != STOP_WINDOW) { 575 blockSwitchingControlRight->lastWindowSequence = LONG_WINDOW; 576 blockSwitchingControlRight->windowShape = LOL_WINDOW; 577 } 578 } 579 } 580 581 return 0; 582 } 583
