1/* 2 * IMC compatible decoder 3 * Copyright (c) 2002-2004 Maxim Poliakovski 4 * Copyright (c) 2006 Benjamin Larsson 5 * Copyright (c) 2006 Konstantin Shishkov 6 * 7 * This file is part of Libav. 8 * 9 * Libav is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU Lesser General Public 11 * License as published by the Free Software Foundation; either 12 * version 2.1 of the License, or (at your option) any later version. 13 * 14 * Libav is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 17 * Lesser General Public License for more details. 18 * 19 * You should have received a copy of the GNU Lesser General Public 20 * License along with Libav; if not, write to the Free Software 21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 22 */ 23 24/** 25 * @file 26 * IMC - Intel Music Coder 27 * A mdct based codec using a 256 points large transform 28 * divied into 32 bands with some mix of scale factors. 29 * Only mono is supported. 30 * 31 */ 32 33 34#include <math.h> 35#include <stddef.h> 36#include <stdio.h> 37 38#include "avcodec.h" 39#include "get_bits.h" 40#include "dsputil.h" 41#include "fft.h" 42#include "libavutil/audioconvert.h" 43#include "sinewin.h" 44 45#include "imcdata.h" 46 47#define IMC_BLOCK_SIZE 64 48#define IMC_FRAME_ID 0x21 49#define BANDS 32 50#define COEFFS 256 51 52typedef struct { 53 AVFrame frame; 54 55 float old_floor[BANDS]; 56 float flcoeffs1[BANDS]; 57 float flcoeffs2[BANDS]; 58 float flcoeffs3[BANDS]; 59 float flcoeffs4[BANDS]; 60 float flcoeffs5[BANDS]; 61 float flcoeffs6[BANDS]; 62 float CWdecoded[COEFFS]; 63 64 /** MDCT tables */ 65 //@{ 66 float mdct_sine_window[COEFFS]; 67 float post_cos[COEFFS]; 68 float post_sin[COEFFS]; 69 float pre_coef1[COEFFS]; 70 float pre_coef2[COEFFS]; 71 float last_fft_im[COEFFS]; 72 //@} 73 74 int bandWidthT[BANDS]; ///< codewords per band 75 int bitsBandT[BANDS]; ///< how many bits per codeword in band 76 int CWlengthT[COEFFS]; ///< how many bits in each codeword 77 int levlCoeffBuf[BANDS]; 78 int bandFlagsBuf[BANDS]; ///< flags for each band 79 int sumLenArr[BANDS]; ///< bits for all coeffs in band 80 int skipFlagRaw[BANDS]; ///< skip flags are stored in raw form or not 81 int skipFlagBits[BANDS]; ///< bits used to code skip flags 82 int skipFlagCount[BANDS]; ///< skipped coeffients per band 83 int skipFlags[COEFFS]; ///< skip coefficient decoding or not 84 int codewords[COEFFS]; ///< raw codewords read from bitstream 85 float sqrt_tab[30]; 86 GetBitContext gb; 87 int decoder_reset; 88 float one_div_log2; 89 90 DSPContext dsp; 91 FFTContext fft; 92 DECLARE_ALIGNED(32, FFTComplex, samples)[COEFFS/2]; 93 float *out_samples; 94} IMCContext; 95 96static VLC huffman_vlc[4][4]; 97 98#define VLC_TABLES_SIZE 9512 99 100static const int vlc_offsets[17] = { 101 0, 640, 1156, 1732, 2308, 2852, 3396, 3924, 102 4452, 5220, 5860, 6628, 7268, 7908, 8424, 8936, VLC_TABLES_SIZE}; 103 104static VLC_TYPE vlc_tables[VLC_TABLES_SIZE][2]; 105 106static av_cold int imc_decode_init(AVCodecContext * avctx) 107{ 108 int i, j, ret; 109 IMCContext *q = avctx->priv_data; 110 double r1, r2; 111 112 if (avctx->channels != 1) { 113 av_log_ask_for_sample(avctx, "Number of channels is not supported\n"); 114 return AVERROR_PATCHWELCOME; 115 } 116 117 q->decoder_reset = 1; 118 119 for(i = 0; i < BANDS; i++) 120 q->old_floor[i] = 1.0; 121 122 /* Build mdct window, a simple sine window normalized with sqrt(2) */ 123 ff_sine_window_init(q->mdct_sine_window, COEFFS); 124 for(i = 0; i < COEFFS; i++) 125 q->mdct_sine_window[i] *= sqrt(2.0); 126 for(i = 0; i < COEFFS/2; i++){ 127 q->post_cos[i] = (1.0f / 32768) * cos(i / 256.0 * M_PI); 128 q->post_sin[i] = (1.0f / 32768) * sin(i / 256.0 * M_PI); 129 130 r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI); 131 r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI); 132 133 if (i & 0x1) 134 { 135 q->pre_coef1[i] = (r1 + r2) * sqrt(2.0); 136 q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0); 137 } 138 else 139 { 140 q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0); 141 q->pre_coef2[i] = (r1 - r2) * sqrt(2.0); 142 } 143 144 q->last_fft_im[i] = 0; 145 } 146 147 /* Generate a square root table */ 148 149 for(i = 0; i < 30; i++) { 150 q->sqrt_tab[i] = sqrt(i); 151 } 152 153 /* initialize the VLC tables */ 154 for(i = 0; i < 4 ; i++) { 155 for(j = 0; j < 4; j++) { 156 huffman_vlc[i][j].table = &vlc_tables[vlc_offsets[i * 4 + j]]; 157 huffman_vlc[i][j].table_allocated = vlc_offsets[i * 4 + j + 1] - vlc_offsets[i * 4 + j]; 158 init_vlc(&huffman_vlc[i][j], 9, imc_huffman_sizes[i], 159 imc_huffman_lens[i][j], 1, 1, 160 imc_huffman_bits[i][j], 2, 2, INIT_VLC_USE_NEW_STATIC); 161 } 162 } 163 q->one_div_log2 = 1/log(2); 164 165 if ((ret = ff_fft_init(&q->fft, 7, 1))) { 166 av_log(avctx, AV_LOG_INFO, "FFT init failed\n"); 167 return ret; 168 } 169 dsputil_init(&q->dsp, avctx); 170 avctx->sample_fmt = AV_SAMPLE_FMT_FLT; 171 avctx->channel_layout = AV_CH_LAYOUT_MONO; 172 173 avcodec_get_frame_defaults(&q->frame); 174 avctx->coded_frame = &q->frame; 175 176 return 0; 177} 178 179static void imc_calculate_coeffs(IMCContext* q, float* flcoeffs1, float* flcoeffs2, int* bandWidthT, 180 float* flcoeffs3, float* flcoeffs5) 181{ 182 float workT1[BANDS]; 183 float workT2[BANDS]; 184 float workT3[BANDS]; 185 float snr_limit = 1.e-30; 186 float accum = 0.0; 187 int i, cnt2; 188 189 for(i = 0; i < BANDS; i++) { 190 flcoeffs5[i] = workT2[i] = 0.0; 191 if (bandWidthT[i]){ 192 workT1[i] = flcoeffs1[i] * flcoeffs1[i]; 193 flcoeffs3[i] = 2.0 * flcoeffs2[i]; 194 } else { 195 workT1[i] = 0.0; 196 flcoeffs3[i] = -30000.0; 197 } 198 workT3[i] = bandWidthT[i] * workT1[i] * 0.01; 199 if (workT3[i] <= snr_limit) 200 workT3[i] = 0.0; 201 } 202 203 for(i = 0; i < BANDS; i++) { 204 for(cnt2 = i; cnt2 < cyclTab[i]; cnt2++) 205 flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i]; 206 workT2[cnt2-1] = workT2[cnt2-1] + workT3[i]; 207 } 208 209 for(i = 1; i < BANDS; i++) { 210 accum = (workT2[i-1] + accum) * imc_weights1[i-1]; 211 flcoeffs5[i] += accum; 212 } 213 214 for(i = 0; i < BANDS; i++) 215 workT2[i] = 0.0; 216 217 for(i = 0; i < BANDS; i++) { 218 for(cnt2 = i-1; cnt2 > cyclTab2[i]; cnt2--) 219 flcoeffs5[cnt2] += workT3[i]; 220 workT2[cnt2+1] += workT3[i]; 221 } 222 223 accum = 0.0; 224 225 for(i = BANDS-2; i >= 0; i--) { 226 accum = (workT2[i+1] + accum) * imc_weights2[i]; 227 flcoeffs5[i] += accum; 228 //there is missing code here, but it seems to never be triggered 229 } 230} 231 232 233static void imc_read_level_coeffs(IMCContext* q, int stream_format_code, int* levlCoeffs) 234{ 235 int i; 236 VLC *hufftab[4]; 237 int start = 0; 238 const uint8_t *cb_sel; 239 int s; 240 241 s = stream_format_code >> 1; 242 hufftab[0] = &huffman_vlc[s][0]; 243 hufftab[1] = &huffman_vlc[s][1]; 244 hufftab[2] = &huffman_vlc[s][2]; 245 hufftab[3] = &huffman_vlc[s][3]; 246 cb_sel = imc_cb_select[s]; 247 248 if(stream_format_code & 4) 249 start = 1; 250 if(start) 251 levlCoeffs[0] = get_bits(&q->gb, 7); 252 for(i = start; i < BANDS; i++){ 253 levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table, hufftab[cb_sel[i]]->bits, 2); 254 if(levlCoeffs[i] == 17) 255 levlCoeffs[i] += get_bits(&q->gb, 4); 256 } 257} 258 259static void imc_decode_level_coefficients(IMCContext* q, int* levlCoeffBuf, float* flcoeffs1, 260 float* flcoeffs2) 261{ 262 int i, level; 263 float tmp, tmp2; 264 //maybe some frequency division thingy 265 266 flcoeffs1[0] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125 267 flcoeffs2[0] = log(flcoeffs1[0])/log(2); 268 tmp = flcoeffs1[0]; 269 tmp2 = flcoeffs2[0]; 270 271 for(i = 1; i < BANDS; i++) { 272 level = levlCoeffBuf[i]; 273 if (level == 16) { 274 flcoeffs1[i] = 1.0; 275 flcoeffs2[i] = 0.0; 276 } else { 277 if (level < 17) 278 level -=7; 279 else if (level <= 24) 280 level -=32; 281 else 282 level -=16; 283 284 tmp *= imc_exp_tab[15 + level]; 285 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25 286 flcoeffs1[i] = tmp; 287 flcoeffs2[i] = tmp2; 288 } 289 } 290} 291 292 293static void imc_decode_level_coefficients2(IMCContext* q, int* levlCoeffBuf, float* old_floor, float* flcoeffs1, 294 float* flcoeffs2) { 295 int i; 296 //FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors 297 // and flcoeffs2 old scale factors 298 // might be incomplete due to a missing table that is in the binary code 299 for(i = 0; i < BANDS; i++) { 300 flcoeffs1[i] = 0; 301 if(levlCoeffBuf[i] < 16) { 302 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i]; 303 flcoeffs2[i] = (levlCoeffBuf[i]-7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25 304 } else { 305 flcoeffs1[i] = old_floor[i]; 306 } 307 } 308} 309 310/** 311 * Perform bit allocation depending on bits available 312 */ 313static int bit_allocation (IMCContext* q, int stream_format_code, int freebits, int flag) { 314 int i, j; 315 const float limit = -1.e20; 316 float highest = 0.0; 317 int indx; 318 int t1 = 0; 319 int t2 = 1; 320 float summa = 0.0; 321 int iacc = 0; 322 int summer = 0; 323 int rres, cwlen; 324 float lowest = 1.e10; 325 int low_indx = 0; 326 float workT[32]; 327 int flg; 328 int found_indx = 0; 329 330 for(i = 0; i < BANDS; i++) 331 highest = FFMAX(highest, q->flcoeffs1[i]); 332 333 for(i = 0; i < BANDS-1; i++) { 334 q->flcoeffs4[i] = q->flcoeffs3[i] - log(q->flcoeffs5[i])/log(2); 335 } 336 q->flcoeffs4[BANDS - 1] = limit; 337 338 highest = highest * 0.25; 339 340 for(i = 0; i < BANDS; i++) { 341 indx = -1; 342 if ((band_tab[i+1] - band_tab[i]) == q->bandWidthT[i]) 343 indx = 0; 344 345 if ((band_tab[i+1] - band_tab[i]) > q->bandWidthT[i]) 346 indx = 1; 347 348 if (((band_tab[i+1] - band_tab[i])/2) >= q->bandWidthT[i]) 349 indx = 2; 350 351 if (indx == -1) 352 return AVERROR_INVALIDDATA; 353 354 q->flcoeffs4[i] = q->flcoeffs4[i] + xTab[(indx*2 + (q->flcoeffs1[i] < highest)) * 2 + flag]; 355 } 356 357 if (stream_format_code & 0x2) { 358 q->flcoeffs4[0] = limit; 359 q->flcoeffs4[1] = limit; 360 q->flcoeffs4[2] = limit; 361 q->flcoeffs4[3] = limit; 362 } 363 364 for(i = (stream_format_code & 0x2)?4:0; i < BANDS-1; i++) { 365 iacc += q->bandWidthT[i]; 366 summa += q->bandWidthT[i] * q->flcoeffs4[i]; 367 } 368 q->bandWidthT[BANDS-1] = 0; 369 summa = (summa * 0.5 - freebits) / iacc; 370 371 372 for(i = 0; i < BANDS/2; i++) { 373 rres = summer - freebits; 374 if((rres >= -8) && (rres <= 8)) break; 375 376 summer = 0; 377 iacc = 0; 378 379 for(j = (stream_format_code & 0x2)?4:0; j < BANDS; j++) { 380 cwlen = av_clipf(((q->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6); 381 382 q->bitsBandT[j] = cwlen; 383 summer += q->bandWidthT[j] * cwlen; 384 385 if (cwlen > 0) 386 iacc += q->bandWidthT[j]; 387 } 388 389 flg = t2; 390 t2 = 1; 391 if (freebits < summer) 392 t2 = -1; 393 if (i == 0) 394 flg = t2; 395 if(flg != t2) 396 t1++; 397 398 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa; 399 } 400 401 for(i = (stream_format_code & 0x2)?4:0; i < BANDS; i++) { 402 for(j = band_tab[i]; j < band_tab[i+1]; j++) 403 q->CWlengthT[j] = q->bitsBandT[i]; 404 } 405 406 if (freebits > summer) { 407 for(i = 0; i < BANDS; i++) { 408 workT[i] = (q->bitsBandT[i] == 6) ? -1.e20 : (q->bitsBandT[i] * -2 + q->flcoeffs4[i] - 0.415); 409 } 410 411 highest = 0.0; 412 413 do{ 414 if (highest <= -1.e20) 415 break; 416 417 found_indx = 0; 418 highest = -1.e20; 419 420 for(i = 0; i < BANDS; i++) { 421 if (workT[i] > highest) { 422 highest = workT[i]; 423 found_indx = i; 424 } 425 } 426 427 if (highest > -1.e20) { 428 workT[found_indx] -= 2.0; 429 if (++(q->bitsBandT[found_indx]) == 6) 430 workT[found_indx] = -1.e20; 431 432 for(j = band_tab[found_indx]; j < band_tab[found_indx+1] && (freebits > summer); j++){ 433 q->CWlengthT[j]++; 434 summer++; 435 } 436 } 437 }while (freebits > summer); 438 } 439 if (freebits < summer) { 440 for(i = 0; i < BANDS; i++) { 441 workT[i] = q->bitsBandT[i] ? (q->bitsBandT[i] * -2 + q->flcoeffs4[i] + 1.585) : 1.e20; 442 } 443 if (stream_format_code & 0x2) { 444 workT[0] = 1.e20; 445 workT[1] = 1.e20; 446 workT[2] = 1.e20; 447 workT[3] = 1.e20; 448 } 449 while (freebits < summer){ 450 lowest = 1.e10; 451 low_indx = 0; 452 for(i = 0; i < BANDS; i++) { 453 if (workT[i] < lowest) { 454 lowest = workT[i]; 455 low_indx = i; 456 } 457 } 458 //if(lowest >= 1.e10) break; 459 workT[low_indx] = lowest + 2.0; 460 461 if (!(--q->bitsBandT[low_indx])) 462 workT[low_indx] = 1.e20; 463 464 for(j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++){ 465 if(q->CWlengthT[j] > 0){ 466 q->CWlengthT[j]--; 467 summer--; 468 } 469 } 470 } 471 } 472 return 0; 473} 474 475static void imc_get_skip_coeff(IMCContext* q) { 476 int i, j; 477 478 memset(q->skipFlagBits, 0, sizeof(q->skipFlagBits)); 479 memset(q->skipFlagCount, 0, sizeof(q->skipFlagCount)); 480 for(i = 0; i < BANDS; i++) { 481 if (!q->bandFlagsBuf[i] || !q->bandWidthT[i]) 482 continue; 483 484 if (!q->skipFlagRaw[i]) { 485 q->skipFlagBits[i] = band_tab[i+1] - band_tab[i]; 486 487 for(j = band_tab[i]; j < band_tab[i+1]; j++) { 488 if ((q->skipFlags[j] = get_bits1(&q->gb))) 489 q->skipFlagCount[i]++; 490 } 491 } else { 492 for(j = band_tab[i]; j < (band_tab[i+1]-1); j += 2) { 493 if(!get_bits1(&q->gb)){//0 494 q->skipFlagBits[i]++; 495 q->skipFlags[j]=1; 496 q->skipFlags[j+1]=1; 497 q->skipFlagCount[i] += 2; 498 }else{ 499 if(get_bits1(&q->gb)){//11 500 q->skipFlagBits[i] +=2; 501 q->skipFlags[j]=0; 502 q->skipFlags[j+1]=1; 503 q->skipFlagCount[i]++; 504 }else{ 505 q->skipFlagBits[i] +=3; 506 q->skipFlags[j+1]=0; 507 if(!get_bits1(&q->gb)){//100 508 q->skipFlags[j]=1; 509 q->skipFlagCount[i]++; 510 }else{//101 511 q->skipFlags[j]=0; 512 } 513 } 514 } 515 } 516 517 if (j < band_tab[i+1]) { 518 q->skipFlagBits[i]++; 519 if ((q->skipFlags[j] = get_bits1(&q->gb))) 520 q->skipFlagCount[i]++; 521 } 522 } 523 } 524} 525 526/** 527 * Increase highest' band coefficient sizes as some bits won't be used 528 */ 529static void imc_adjust_bit_allocation (IMCContext* q, int summer) { 530 float workT[32]; 531 int corrected = 0; 532 int i, j; 533 float highest = 0; 534 int found_indx=0; 535 536 for(i = 0; i < BANDS; i++) { 537 workT[i] = (q->bitsBandT[i] == 6) ? -1.e20 : (q->bitsBandT[i] * -2 + q->flcoeffs4[i] - 0.415); 538 } 539 540 while (corrected < summer) { 541 if(highest <= -1.e20) 542 break; 543 544 highest = -1.e20; 545 546 for(i = 0; i < BANDS; i++) { 547 if (workT[i] > highest) { 548 highest = workT[i]; 549 found_indx = i; 550 } 551 } 552 553 if (highest > -1.e20) { 554 workT[found_indx] -= 2.0; 555 if (++(q->bitsBandT[found_indx]) == 6) 556 workT[found_indx] = -1.e20; 557 558 for(j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) { 559 if (!q->skipFlags[j] && (q->CWlengthT[j] < 6)) { 560 q->CWlengthT[j]++; 561 corrected++; 562 } 563 } 564 } 565 } 566} 567 568static void imc_imdct256(IMCContext *q) { 569 int i; 570 float re, im; 571 572 /* prerotation */ 573 for(i=0; i < COEFFS/2; i++){ 574 q->samples[i].re = -(q->pre_coef1[i] * q->CWdecoded[COEFFS-1-i*2]) - 575 (q->pre_coef2[i] * q->CWdecoded[i*2]); 576 q->samples[i].im = (q->pre_coef2[i] * q->CWdecoded[COEFFS-1-i*2]) - 577 (q->pre_coef1[i] * q->CWdecoded[i*2]); 578 } 579 580 /* FFT */ 581 q->fft.fft_permute(&q->fft, q->samples); 582 q->fft.fft_calc (&q->fft, q->samples); 583 584 /* postrotation, window and reorder */ 585 for(i = 0; i < COEFFS/2; i++){ 586 re = (q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]); 587 im = (-q->samples[i].im * q->post_cos[i]) - (q->samples[i].re * q->post_sin[i]); 588 q->out_samples[i*2] = (q->mdct_sine_window[COEFFS-1-i*2] * q->last_fft_im[i]) + (q->mdct_sine_window[i*2] * re); 589 q->out_samples[COEFFS-1-i*2] = (q->mdct_sine_window[i*2] * q->last_fft_im[i]) - (q->mdct_sine_window[COEFFS-1-i*2] * re); 590 q->last_fft_im[i] = im; 591 } 592} 593 594static int inverse_quant_coeff (IMCContext* q, int stream_format_code) { 595 int i, j; 596 int middle_value, cw_len, max_size; 597 const float* quantizer; 598 599 for(i = 0; i < BANDS; i++) { 600 for(j = band_tab[i]; j < band_tab[i+1]; j++) { 601 q->CWdecoded[j] = 0; 602 cw_len = q->CWlengthT[j]; 603 604 if (cw_len <= 0 || q->skipFlags[j]) 605 continue; 606 607 max_size = 1 << cw_len; 608 middle_value = max_size >> 1; 609 610 if (q->codewords[j] >= max_size || q->codewords[j] < 0) 611 return AVERROR_INVALIDDATA; 612 613 if (cw_len >= 4){ 614 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1]; 615 if (q->codewords[j] >= middle_value) 616 q->CWdecoded[j] = quantizer[q->codewords[j] - 8] * q->flcoeffs6[i]; 617 else 618 q->CWdecoded[j] = -quantizer[max_size - q->codewords[j] - 8 - 1] * q->flcoeffs6[i]; 619 }else{ 620 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (q->bandFlagsBuf[i] << 1)]; 621 if (q->codewords[j] >= middle_value) 622 q->CWdecoded[j] = quantizer[q->codewords[j] - 1] * q->flcoeffs6[i]; 623 else 624 q->CWdecoded[j] = -quantizer[max_size - 2 - q->codewords[j]] * q->flcoeffs6[i]; 625 } 626 } 627 } 628 return 0; 629} 630 631 632static int imc_get_coeffs (IMCContext* q) { 633 int i, j, cw_len, cw; 634 635 for(i = 0; i < BANDS; i++) { 636 if(!q->sumLenArr[i]) continue; 637 if (q->bandFlagsBuf[i] || q->bandWidthT[i]) { 638 for(j = band_tab[i]; j < band_tab[i+1]; j++) { 639 cw_len = q->CWlengthT[j]; 640 cw = 0; 641 642 if (get_bits_count(&q->gb) + cw_len > 512){ 643//av_log(NULL,0,"Band %i coeff %i cw_len %i\n",i,j,cw_len); 644 return AVERROR_INVALIDDATA; 645 } 646 647 if(cw_len && (!q->bandFlagsBuf[i] || !q->skipFlags[j])) 648 cw = get_bits(&q->gb, cw_len); 649 650 q->codewords[j] = cw; 651 } 652 } 653 } 654 return 0; 655} 656 657static int imc_decode_frame(AVCodecContext * avctx, void *data, 658 int *got_frame_ptr, AVPacket *avpkt) 659{ 660 const uint8_t *buf = avpkt->data; 661 int buf_size = avpkt->size; 662 663 IMCContext *q = avctx->priv_data; 664 665 int stream_format_code; 666 int imc_hdr, i, j, ret; 667 int flag; 668 int bits, summer; 669 int counter, bitscount; 670 LOCAL_ALIGNED_16(uint16_t, buf16, [IMC_BLOCK_SIZE / 2]); 671 672 if (buf_size < IMC_BLOCK_SIZE) { 673 av_log(avctx, AV_LOG_ERROR, "imc frame too small!\n"); 674 return AVERROR_INVALIDDATA; 675 } 676 677 /* get output buffer */ 678 q->frame.nb_samples = COEFFS; 679 if ((ret = avctx->get_buffer(avctx, &q->frame)) < 0) { 680 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 681 return ret; 682 } 683 q->out_samples = (float *)q->frame.data[0]; 684 685 q->dsp.bswap16_buf(buf16, (const uint16_t*)buf, IMC_BLOCK_SIZE / 2); 686 687 init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8); 688 689 /* Check the frame header */ 690 imc_hdr = get_bits(&q->gb, 9); 691 if (imc_hdr != IMC_FRAME_ID) { 692 av_log(avctx, AV_LOG_ERROR, "imc frame header check failed!\n"); 693 av_log(avctx, AV_LOG_ERROR, "got %x instead of 0x21.\n", imc_hdr); 694 return AVERROR_INVALIDDATA; 695 } 696 stream_format_code = get_bits(&q->gb, 3); 697 698 if(stream_format_code & 1){ 699 av_log(avctx, AV_LOG_ERROR, "Stream code format %X is not supported\n", stream_format_code); 700 return AVERROR_INVALIDDATA; 701 } 702 703// av_log(avctx, AV_LOG_DEBUG, "stream_format_code = %d\n", stream_format_code); 704 705 if (stream_format_code & 0x04) 706 q->decoder_reset = 1; 707 708 if(q->decoder_reset) { 709 memset(q->out_samples, 0, sizeof(q->out_samples)); 710 for(i = 0; i < BANDS; i++)q->old_floor[i] = 1.0; 711 for(i = 0; i < COEFFS; i++)q->CWdecoded[i] = 0; 712 q->decoder_reset = 0; 713 } 714 715 flag = get_bits1(&q->gb); 716 imc_read_level_coeffs(q, stream_format_code, q->levlCoeffBuf); 717 718 if (stream_format_code & 0x4) 719 imc_decode_level_coefficients(q, q->levlCoeffBuf, q->flcoeffs1, q->flcoeffs2); 720 else 721 imc_decode_level_coefficients2(q, q->levlCoeffBuf, q->old_floor, q->flcoeffs1, q->flcoeffs2); 722 723 memcpy(q->old_floor, q->flcoeffs1, 32 * sizeof(float)); 724 725 counter = 0; 726 for (i=0 ; i<BANDS ; i++) { 727 if (q->levlCoeffBuf[i] == 16) { 728 q->bandWidthT[i] = 0; 729 counter++; 730 } else 731 q->bandWidthT[i] = band_tab[i+1] - band_tab[i]; 732 } 733 memset(q->bandFlagsBuf, 0, BANDS * sizeof(int)); 734 for(i = 0; i < BANDS-1; i++) { 735 if (q->bandWidthT[i]) 736 q->bandFlagsBuf[i] = get_bits1(&q->gb); 737 } 738 739 imc_calculate_coeffs(q, q->flcoeffs1, q->flcoeffs2, q->bandWidthT, q->flcoeffs3, q->flcoeffs5); 740 741 bitscount = 0; 742 /* first 4 bands will be assigned 5 bits per coefficient */ 743 if (stream_format_code & 0x2) { 744 bitscount += 15; 745 746 q->bitsBandT[0] = 5; 747 q->CWlengthT[0] = 5; 748 q->CWlengthT[1] = 5; 749 q->CWlengthT[2] = 5; 750 for(i = 1; i < 4; i++){ 751 bits = (q->levlCoeffBuf[i] == 16) ? 0 : 5; 752 q->bitsBandT[i] = bits; 753 for(j = band_tab[i]; j < band_tab[i+1]; j++) { 754 q->CWlengthT[j] = bits; 755 bitscount += bits; 756 } 757 } 758 } 759 760 if((ret = bit_allocation (q, stream_format_code, 761 512 - bitscount - get_bits_count(&q->gb), flag)) < 0) { 762 av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n"); 763 q->decoder_reset = 1; 764 return ret; 765 } 766 767 for(i = 0; i < BANDS; i++) { 768 q->sumLenArr[i] = 0; 769 q->skipFlagRaw[i] = 0; 770 for(j = band_tab[i]; j < band_tab[i+1]; j++) 771 q->sumLenArr[i] += q->CWlengthT[j]; 772 if (q->bandFlagsBuf[i]) 773 if( (((band_tab[i+1] - band_tab[i]) * 1.5) > q->sumLenArr[i]) && (q->sumLenArr[i] > 0)) 774 q->skipFlagRaw[i] = 1; 775 } 776 777 imc_get_skip_coeff(q); 778 779 for(i = 0; i < BANDS; i++) { 780 q->flcoeffs6[i] = q->flcoeffs1[i]; 781 /* band has flag set and at least one coded coefficient */ 782 if (q->bandFlagsBuf[i] && (band_tab[i+1] - band_tab[i]) != q->skipFlagCount[i]){ 783 q->flcoeffs6[i] *= q->sqrt_tab[band_tab[i+1] - band_tab[i]] / 784 q->sqrt_tab[(band_tab[i+1] - band_tab[i] - q->skipFlagCount[i])]; 785 } 786 } 787 788 /* calculate bits left, bits needed and adjust bit allocation */ 789 bits = summer = 0; 790 791 for(i = 0; i < BANDS; i++) { 792 if (q->bandFlagsBuf[i]) { 793 for(j = band_tab[i]; j < band_tab[i+1]; j++) { 794 if(q->skipFlags[j]) { 795 summer += q->CWlengthT[j]; 796 q->CWlengthT[j] = 0; 797 } 798 } 799 bits += q->skipFlagBits[i]; 800 summer -= q->skipFlagBits[i]; 801 } 802 } 803 imc_adjust_bit_allocation(q, summer); 804 805 for(i = 0; i < BANDS; i++) { 806 q->sumLenArr[i] = 0; 807 808 for(j = band_tab[i]; j < band_tab[i+1]; j++) 809 if (!q->skipFlags[j]) 810 q->sumLenArr[i] += q->CWlengthT[j]; 811 } 812 813 memset(q->codewords, 0, sizeof(q->codewords)); 814 815 if(imc_get_coeffs(q) < 0) { 816 av_log(avctx, AV_LOG_ERROR, "Read coefficients failed\n"); 817 q->decoder_reset = 1; 818 return AVERROR_INVALIDDATA; 819 } 820 821 if(inverse_quant_coeff(q, stream_format_code) < 0) { 822 av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n"); 823 q->decoder_reset = 1; 824 return AVERROR_INVALIDDATA; 825 } 826 827 memset(q->skipFlags, 0, sizeof(q->skipFlags)); 828 829 imc_imdct256(q); 830 831 *got_frame_ptr = 1; 832 *(AVFrame *)data = q->frame; 833 834 return IMC_BLOCK_SIZE; 835} 836 837 838static av_cold int imc_decode_close(AVCodecContext * avctx) 839{ 840 IMCContext *q = avctx->priv_data; 841 842 ff_fft_end(&q->fft); 843 844 return 0; 845} 846 847 848AVCodec ff_imc_decoder = { 849 .name = "imc", 850 .type = AVMEDIA_TYPE_AUDIO, 851 .id = CODEC_ID_IMC, 852 .priv_data_size = sizeof(IMCContext), 853 .init = imc_decode_init, 854 .close = imc_decode_close, 855 .decode = imc_decode_frame, 856 .capabilities = CODEC_CAP_DR1, 857 .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"), 858}; 859