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 FFmpeg. 8 * 9 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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 * divided 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 "libavutil/channel_layout.h" 39#include "libavutil/float_dsp.h" 40#include "libavutil/internal.h" 41#include "libavutil/libm.h" 42#include "avcodec.h" 43#include "bswapdsp.h" 44#include "get_bits.h" 45#include "fft.h" 46#include "internal.h" 47#include "sinewin.h" 48 49#include "imcdata.h" 50 51#define IMC_BLOCK_SIZE 64 52#define IMC_FRAME_ID 0x21 53#define BANDS 32 54#define COEFFS 256 55 56typedef struct IMCChannel { 57 float old_floor[BANDS]; 58 float flcoeffs1[BANDS]; 59 float flcoeffs2[BANDS]; 60 float flcoeffs3[BANDS]; 61 float flcoeffs4[BANDS]; 62 float flcoeffs5[BANDS]; 63 float flcoeffs6[BANDS]; 64 float CWdecoded[COEFFS]; 65 66 int bandWidthT[BANDS]; ///< codewords per band 67 int bitsBandT[BANDS]; ///< how many bits per codeword in band 68 int CWlengthT[COEFFS]; ///< how many bits in each codeword 69 int levlCoeffBuf[BANDS]; 70 int bandFlagsBuf[BANDS]; ///< flags for each band 71 int sumLenArr[BANDS]; ///< bits for all coeffs in band 72 int skipFlagRaw[BANDS]; ///< skip flags are stored in raw form or not 73 int skipFlagBits[BANDS]; ///< bits used to code skip flags 74 int skipFlagCount[BANDS]; ///< skipped coeffients per band 75 int skipFlags[COEFFS]; ///< skip coefficient decoding or not 76 int codewords[COEFFS]; ///< raw codewords read from bitstream 77 78 float last_fft_im[COEFFS]; 79 80 int decoder_reset; 81} IMCChannel; 82 83typedef struct { 84 IMCChannel chctx[2]; 85 86 /** MDCT tables */ 87 //@{ 88 float mdct_sine_window[COEFFS]; 89 float post_cos[COEFFS]; 90 float post_sin[COEFFS]; 91 float pre_coef1[COEFFS]; 92 float pre_coef2[COEFFS]; 93 //@} 94 95 float sqrt_tab[30]; 96 GetBitContext gb; 97 98 BswapDSPContext bdsp; 99 AVFloatDSPContext fdsp; 100 FFTContext fft; 101 DECLARE_ALIGNED(32, FFTComplex, samples)[COEFFS / 2]; 102 float *out_samples; 103 104 int coef0_pos; 105 106 int8_t cyclTab[32], cyclTab2[32]; 107 float weights1[31], weights2[31]; 108} IMCContext; 109 110static VLC huffman_vlc[4][4]; 111 112#define VLC_TABLES_SIZE 9512 113 114static const int vlc_offsets[17] = { 115 0, 640, 1156, 1732, 2308, 2852, 3396, 3924, 116 4452, 5220, 5860, 6628, 7268, 7908, 8424, 8936, VLC_TABLES_SIZE 117}; 118 119static VLC_TYPE vlc_tables[VLC_TABLES_SIZE][2]; 120 121static inline double freq2bark(double freq) 122{ 123 return 3.5 * atan((freq / 7500.0) * (freq / 7500.0)) + 13.0 * atan(freq * 0.00076); 124} 125 126static av_cold void iac_generate_tabs(IMCContext *q, int sampling_rate) 127{ 128 double freqmin[32], freqmid[32], freqmax[32]; 129 double scale = sampling_rate / (256.0 * 2.0 * 2.0); 130 double nyquist_freq = sampling_rate * 0.5; 131 double freq, bark, prev_bark = 0, tf, tb; 132 int i, j; 133 134 for (i = 0; i < 32; i++) { 135 freq = (band_tab[i] + band_tab[i + 1] - 1) * scale; 136 bark = freq2bark(freq); 137 138 if (i > 0) { 139 tb = bark - prev_bark; 140 q->weights1[i - 1] = pow(10.0, -1.0 * tb); 141 q->weights2[i - 1] = pow(10.0, -2.7 * tb); 142 } 143 prev_bark = bark; 144 145 freqmid[i] = freq; 146 147 tf = freq; 148 while (tf < nyquist_freq) { 149 tf += 0.5; 150 tb = freq2bark(tf); 151 if (tb > bark + 0.5) 152 break; 153 } 154 freqmax[i] = tf; 155 156 tf = freq; 157 while (tf > 0.0) { 158 tf -= 0.5; 159 tb = freq2bark(tf); 160 if (tb <= bark - 0.5) 161 break; 162 } 163 freqmin[i] = tf; 164 } 165 166 for (i = 0; i < 32; i++) { 167 freq = freqmax[i]; 168 for (j = 31; j > 0 && freq <= freqmid[j]; j--); 169 q->cyclTab[i] = j + 1; 170 171 freq = freqmin[i]; 172 for (j = 0; j < 32 && freq >= freqmid[j]; j++); 173 q->cyclTab2[i] = j - 1; 174 } 175} 176 177static av_cold int imc_decode_init(AVCodecContext *avctx) 178{ 179 int i, j, ret; 180 IMCContext *q = avctx->priv_data; 181 double r1, r2; 182 183 if (avctx->codec_id == AV_CODEC_ID_IMC) 184 avctx->channels = 1; 185 186 if (avctx->channels > 2) { 187 avpriv_request_sample(avctx, "Number of channels > 2"); 188 return AVERROR_PATCHWELCOME; 189 } 190 191 for (j = 0; j < avctx->channels; j++) { 192 q->chctx[j].decoder_reset = 1; 193 194 for (i = 0; i < BANDS; i++) 195 q->chctx[j].old_floor[i] = 1.0; 196 197 for (i = 0; i < COEFFS / 2; i++) 198 q->chctx[j].last_fft_im[i] = 0; 199 } 200 201 /* Build mdct window, a simple sine window normalized with sqrt(2) */ 202 ff_sine_window_init(q->mdct_sine_window, COEFFS); 203 for (i = 0; i < COEFFS; i++) 204 q->mdct_sine_window[i] *= sqrt(2.0); 205 for (i = 0; i < COEFFS / 2; i++) { 206 q->post_cos[i] = (1.0f / 32768) * cos(i / 256.0 * M_PI); 207 q->post_sin[i] = (1.0f / 32768) * sin(i / 256.0 * M_PI); 208 209 r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI); 210 r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI); 211 212 if (i & 0x1) { 213 q->pre_coef1[i] = (r1 + r2) * sqrt(2.0); 214 q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0); 215 } else { 216 q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0); 217 q->pre_coef2[i] = (r1 - r2) * sqrt(2.0); 218 } 219 } 220 221 /* Generate a square root table */ 222 223 for (i = 0; i < 30; i++) 224 q->sqrt_tab[i] = sqrt(i); 225 226 /* initialize the VLC tables */ 227 for (i = 0; i < 4 ; i++) { 228 for (j = 0; j < 4; j++) { 229 huffman_vlc[i][j].table = &vlc_tables[vlc_offsets[i * 4 + j]]; 230 huffman_vlc[i][j].table_allocated = vlc_offsets[i * 4 + j + 1] - vlc_offsets[i * 4 + j]; 231 init_vlc(&huffman_vlc[i][j], 9, imc_huffman_sizes[i], 232 imc_huffman_lens[i][j], 1, 1, 233 imc_huffman_bits[i][j], 2, 2, INIT_VLC_USE_NEW_STATIC); 234 } 235 } 236 237 if (avctx->codec_id == AV_CODEC_ID_IAC) { 238 iac_generate_tabs(q, avctx->sample_rate); 239 } else { 240 memcpy(q->cyclTab, cyclTab, sizeof(cyclTab)); 241 memcpy(q->cyclTab2, cyclTab2, sizeof(cyclTab2)); 242 memcpy(q->weights1, imc_weights1, sizeof(imc_weights1)); 243 memcpy(q->weights2, imc_weights2, sizeof(imc_weights2)); 244 } 245 246 if ((ret = ff_fft_init(&q->fft, 7, 1))) { 247 av_log(avctx, AV_LOG_INFO, "FFT init failed\n"); 248 return ret; 249 } 250 ff_bswapdsp_init(&q->bdsp); 251 avpriv_float_dsp_init(&q->fdsp, avctx->flags & CODEC_FLAG_BITEXACT); 252 avctx->sample_fmt = AV_SAMPLE_FMT_FLTP; 253 avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO 254 : AV_CH_LAYOUT_STEREO; 255 256 return 0; 257} 258 259static void imc_calculate_coeffs(IMCContext *q, float *flcoeffs1, 260 float *flcoeffs2, int *bandWidthT, 261 float *flcoeffs3, float *flcoeffs5) 262{ 263 float workT1[BANDS]; 264 float workT2[BANDS]; 265 float workT3[BANDS]; 266 float snr_limit = 1.e-30; 267 float accum = 0.0; 268 int i, cnt2; 269 270 for (i = 0; i < BANDS; i++) { 271 flcoeffs5[i] = workT2[i] = 0.0; 272 if (bandWidthT[i]) { 273 workT1[i] = flcoeffs1[i] * flcoeffs1[i]; 274 flcoeffs3[i] = 2.0 * flcoeffs2[i]; 275 } else { 276 workT1[i] = 0.0; 277 flcoeffs3[i] = -30000.0; 278 } 279 workT3[i] = bandWidthT[i] * workT1[i] * 0.01; 280 if (workT3[i] <= snr_limit) 281 workT3[i] = 0.0; 282 } 283 284 for (i = 0; i < BANDS; i++) { 285 for (cnt2 = i; cnt2 < q->cyclTab[i]; cnt2++) 286 flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i]; 287 workT2[cnt2 - 1] = workT2[cnt2 - 1] + workT3[i]; 288 } 289 290 for (i = 1; i < BANDS; i++) { 291 accum = (workT2[i - 1] + accum) * q->weights1[i - 1]; 292 flcoeffs5[i] += accum; 293 } 294 295 for (i = 0; i < BANDS; i++) 296 workT2[i] = 0.0; 297 298 for (i = 0; i < BANDS; i++) { 299 for (cnt2 = i - 1; cnt2 > q->cyclTab2[i]; cnt2--) 300 flcoeffs5[cnt2] += workT3[i]; 301 workT2[cnt2+1] += workT3[i]; 302 } 303 304 accum = 0.0; 305 306 for (i = BANDS-2; i >= 0; i--) { 307 accum = (workT2[i+1] + accum) * q->weights2[i]; 308 flcoeffs5[i] += accum; 309 // there is missing code here, but it seems to never be triggered 310 } 311} 312 313 314static void imc_read_level_coeffs(IMCContext *q, int stream_format_code, 315 int *levlCoeffs) 316{ 317 int i; 318 VLC *hufftab[4]; 319 int start = 0; 320 const uint8_t *cb_sel; 321 int s; 322 323 s = stream_format_code >> 1; 324 hufftab[0] = &huffman_vlc[s][0]; 325 hufftab[1] = &huffman_vlc[s][1]; 326 hufftab[2] = &huffman_vlc[s][2]; 327 hufftab[3] = &huffman_vlc[s][3]; 328 cb_sel = imc_cb_select[s]; 329 330 if (stream_format_code & 4) 331 start = 1; 332 if (start) 333 levlCoeffs[0] = get_bits(&q->gb, 7); 334 for (i = start; i < BANDS; i++) { 335 levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table, 336 hufftab[cb_sel[i]]->bits, 2); 337 if (levlCoeffs[i] == 17) 338 levlCoeffs[i] += get_bits(&q->gb, 4); 339 } 340} 341 342static void imc_read_level_coeffs_raw(IMCContext *q, int stream_format_code, 343 int *levlCoeffs) 344{ 345 int i; 346 347 q->coef0_pos = get_bits(&q->gb, 5); 348 levlCoeffs[0] = get_bits(&q->gb, 7); 349 for (i = 1; i < BANDS; i++) 350 levlCoeffs[i] = get_bits(&q->gb, 4); 351} 352 353static void imc_decode_level_coefficients(IMCContext *q, int *levlCoeffBuf, 354 float *flcoeffs1, float *flcoeffs2) 355{ 356 int i, level; 357 float tmp, tmp2; 358 // maybe some frequency division thingy 359 360 flcoeffs1[0] = 20000.0 / exp2 (levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125 361 flcoeffs2[0] = log2f(flcoeffs1[0]); 362 tmp = flcoeffs1[0]; 363 tmp2 = flcoeffs2[0]; 364 365 for (i = 1; i < BANDS; i++) { 366 level = levlCoeffBuf[i]; 367 if (level == 16) { 368 flcoeffs1[i] = 1.0; 369 flcoeffs2[i] = 0.0; 370 } else { 371 if (level < 17) 372 level -= 7; 373 else if (level <= 24) 374 level -= 32; 375 else 376 level -= 16; 377 378 tmp *= imc_exp_tab[15 + level]; 379 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25 380 flcoeffs1[i] = tmp; 381 flcoeffs2[i] = tmp2; 382 } 383 } 384} 385 386 387static void imc_decode_level_coefficients2(IMCContext *q, int *levlCoeffBuf, 388 float *old_floor, float *flcoeffs1, 389 float *flcoeffs2) 390{ 391 int i; 392 /* FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors 393 * and flcoeffs2 old scale factors 394 * might be incomplete due to a missing table that is in the binary code 395 */ 396 for (i = 0; i < BANDS; i++) { 397 flcoeffs1[i] = 0; 398 if (levlCoeffBuf[i] < 16) { 399 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i]; 400 flcoeffs2[i] = (levlCoeffBuf[i] - 7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25 401 } else { 402 flcoeffs1[i] = old_floor[i]; 403 } 404 } 405} 406 407static void imc_decode_level_coefficients_raw(IMCContext *q, int *levlCoeffBuf, 408 float *flcoeffs1, float *flcoeffs2) 409{ 410 int i, level, pos; 411 float tmp, tmp2; 412 413 pos = q->coef0_pos; 414 flcoeffs1[pos] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125 415 flcoeffs2[pos] = log2f(flcoeffs1[0]); 416 tmp = flcoeffs1[pos]; 417 tmp2 = flcoeffs2[pos]; 418 419 levlCoeffBuf++; 420 for (i = 0; i < BANDS; i++) { 421 if (i == pos) 422 continue; 423 level = *levlCoeffBuf++; 424 flcoeffs1[i] = tmp * powf(10.0, -level * 0.4375); //todo tab 425 flcoeffs2[i] = tmp2 - 1.4533435415 * level; // 1.4533435415 = log2(10) * 0.4375 426 } 427} 428 429/** 430 * Perform bit allocation depending on bits available 431 */ 432static int bit_allocation(IMCContext *q, IMCChannel *chctx, 433 int stream_format_code, int freebits, int flag) 434{ 435 int i, j; 436 const float limit = -1.e20; 437 float highest = 0.0; 438 int indx; 439 int t1 = 0; 440 int t2 = 1; 441 float summa = 0.0; 442 int iacc = 0; 443 int summer = 0; 444 int rres, cwlen; 445 float lowest = 1.e10; 446 int low_indx = 0; 447 float workT[32]; 448 int flg; 449 int found_indx = 0; 450 451 for (i = 0; i < BANDS; i++) 452 highest = FFMAX(highest, chctx->flcoeffs1[i]); 453 454 for (i = 0; i < BANDS - 1; i++) { 455 if (chctx->flcoeffs5[i] <= 0) { 456 av_log(NULL, AV_LOG_ERROR, "flcoeffs5 %f invalid\n", chctx->flcoeffs5[i]); 457 return AVERROR_INVALIDDATA; 458 } 459 chctx->flcoeffs4[i] = chctx->flcoeffs3[i] - log2f(chctx->flcoeffs5[i]); 460 } 461 chctx->flcoeffs4[BANDS - 1] = limit; 462 463 highest = highest * 0.25; 464 465 for (i = 0; i < BANDS; i++) { 466 indx = -1; 467 if ((band_tab[i + 1] - band_tab[i]) == chctx->bandWidthT[i]) 468 indx = 0; 469 470 if ((band_tab[i + 1] - band_tab[i]) > chctx->bandWidthT[i]) 471 indx = 1; 472 473 if (((band_tab[i + 1] - band_tab[i]) / 2) >= chctx->bandWidthT[i]) 474 indx = 2; 475 476 if (indx == -1) 477 return AVERROR_INVALIDDATA; 478 479 chctx->flcoeffs4[i] += xTab[(indx * 2 + (chctx->flcoeffs1[i] < highest)) * 2 + flag]; 480 } 481 482 if (stream_format_code & 0x2) { 483 chctx->flcoeffs4[0] = limit; 484 chctx->flcoeffs4[1] = limit; 485 chctx->flcoeffs4[2] = limit; 486 chctx->flcoeffs4[3] = limit; 487 } 488 489 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS - 1; i++) { 490 iacc += chctx->bandWidthT[i]; 491 summa += chctx->bandWidthT[i] * chctx->flcoeffs4[i]; 492 } 493 494 if (!iacc) 495 return AVERROR_INVALIDDATA; 496 497 chctx->bandWidthT[BANDS - 1] = 0; 498 summa = (summa * 0.5 - freebits) / iacc; 499 500 501 for (i = 0; i < BANDS / 2; i++) { 502 rres = summer - freebits; 503 if ((rres >= -8) && (rres <= 8)) 504 break; 505 506 summer = 0; 507 iacc = 0; 508 509 for (j = (stream_format_code & 0x2) ? 4 : 0; j < BANDS; j++) { 510 cwlen = av_clipf(((chctx->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6); 511 512 chctx->bitsBandT[j] = cwlen; 513 summer += chctx->bandWidthT[j] * cwlen; 514 515 if (cwlen > 0) 516 iacc += chctx->bandWidthT[j]; 517 } 518 519 flg = t2; 520 t2 = 1; 521 if (freebits < summer) 522 t2 = -1; 523 if (i == 0) 524 flg = t2; 525 if (flg != t2) 526 t1++; 527 528 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa; 529 } 530 531 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS; i++) { 532 for (j = band_tab[i]; j < band_tab[i + 1]; j++) 533 chctx->CWlengthT[j] = chctx->bitsBandT[i]; 534 } 535 536 if (freebits > summer) { 537 for (i = 0; i < BANDS; i++) { 538 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20 539 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415); 540 } 541 542 highest = 0.0; 543 544 do { 545 if (highest <= -1.e20) 546 break; 547 548 found_indx = 0; 549 highest = -1.e20; 550 551 for (i = 0; i < BANDS; i++) { 552 if (workT[i] > highest) { 553 highest = workT[i]; 554 found_indx = i; 555 } 556 } 557 558 if (highest > -1.e20) { 559 workT[found_indx] -= 2.0; 560 if (++chctx->bitsBandT[found_indx] == 6) 561 workT[found_indx] = -1.e20; 562 563 for (j = band_tab[found_indx]; j < band_tab[found_indx + 1] && (freebits > summer); j++) { 564 chctx->CWlengthT[j]++; 565 summer++; 566 } 567 } 568 } while (freebits > summer); 569 } 570 if (freebits < summer) { 571 for (i = 0; i < BANDS; i++) { 572 workT[i] = chctx->bitsBandT[i] ? (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] + 1.585) 573 : 1.e20; 574 } 575 if (stream_format_code & 0x2) { 576 workT[0] = 1.e20; 577 workT[1] = 1.e20; 578 workT[2] = 1.e20; 579 workT[3] = 1.e20; 580 } 581 while (freebits < summer) { 582 lowest = 1.e10; 583 low_indx = 0; 584 for (i = 0; i < BANDS; i++) { 585 if (workT[i] < lowest) { 586 lowest = workT[i]; 587 low_indx = i; 588 } 589 } 590 // if (lowest >= 1.e10) 591 // break; 592 workT[low_indx] = lowest + 2.0; 593 594 if (!--chctx->bitsBandT[low_indx]) 595 workT[low_indx] = 1.e20; 596 597 for (j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++) { 598 if (chctx->CWlengthT[j] > 0) { 599 chctx->CWlengthT[j]--; 600 summer--; 601 } 602 } 603 } 604 } 605 return 0; 606} 607 608static void imc_get_skip_coeff(IMCContext *q, IMCChannel *chctx) 609{ 610 int i, j; 611 612 memset(chctx->skipFlagBits, 0, sizeof(chctx->skipFlagBits)); 613 memset(chctx->skipFlagCount, 0, sizeof(chctx->skipFlagCount)); 614 for (i = 0; i < BANDS; i++) { 615 if (!chctx->bandFlagsBuf[i] || !chctx->bandWidthT[i]) 616 continue; 617 618 if (!chctx->skipFlagRaw[i]) { 619 chctx->skipFlagBits[i] = band_tab[i + 1] - band_tab[i]; 620 621 for (j = band_tab[i]; j < band_tab[i + 1]; j++) { 622 chctx->skipFlags[j] = get_bits1(&q->gb); 623 if (chctx->skipFlags[j]) 624 chctx->skipFlagCount[i]++; 625 } 626 } else { 627 for (j = band_tab[i]; j < band_tab[i + 1] - 1; j += 2) { 628 if (!get_bits1(&q->gb)) { // 0 629 chctx->skipFlagBits[i]++; 630 chctx->skipFlags[j] = 1; 631 chctx->skipFlags[j + 1] = 1; 632 chctx->skipFlagCount[i] += 2; 633 } else { 634 if (get_bits1(&q->gb)) { // 11 635 chctx->skipFlagBits[i] += 2; 636 chctx->skipFlags[j] = 0; 637 chctx->skipFlags[j + 1] = 1; 638 chctx->skipFlagCount[i]++; 639 } else { 640 chctx->skipFlagBits[i] += 3; 641 chctx->skipFlags[j + 1] = 0; 642 if (!get_bits1(&q->gb)) { // 100 643 chctx->skipFlags[j] = 1; 644 chctx->skipFlagCount[i]++; 645 } else { // 101 646 chctx->skipFlags[j] = 0; 647 } 648 } 649 } 650 } 651 652 if (j < band_tab[i + 1]) { 653 chctx->skipFlagBits[i]++; 654 if ((chctx->skipFlags[j] = get_bits1(&q->gb))) 655 chctx->skipFlagCount[i]++; 656 } 657 } 658 } 659} 660 661/** 662 * Increase highest' band coefficient sizes as some bits won't be used 663 */ 664static void imc_adjust_bit_allocation(IMCContext *q, IMCChannel *chctx, 665 int summer) 666{ 667 float workT[32]; 668 int corrected = 0; 669 int i, j; 670 float highest = 0; 671 int found_indx = 0; 672 673 for (i = 0; i < BANDS; i++) { 674 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20 675 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415); 676 } 677 678 while (corrected < summer) { 679 if (highest <= -1.e20) 680 break; 681 682 highest = -1.e20; 683 684 for (i = 0; i < BANDS; i++) { 685 if (workT[i] > highest) { 686 highest = workT[i]; 687 found_indx = i; 688 } 689 } 690 691 if (highest > -1.e20) { 692 workT[found_indx] -= 2.0; 693 if (++(chctx->bitsBandT[found_indx]) == 6) 694 workT[found_indx] = -1.e20; 695 696 for (j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) { 697 if (!chctx->skipFlags[j] && (chctx->CWlengthT[j] < 6)) { 698 chctx->CWlengthT[j]++; 699 corrected++; 700 } 701 } 702 } 703 } 704} 705 706static void imc_imdct256(IMCContext *q, IMCChannel *chctx, int channels) 707{ 708 int i; 709 float re, im; 710 float *dst1 = q->out_samples; 711 float *dst2 = q->out_samples + (COEFFS - 1); 712 713 /* prerotation */ 714 for (i = 0; i < COEFFS / 2; i++) { 715 q->samples[i].re = -(q->pre_coef1[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) - 716 (q->pre_coef2[i] * chctx->CWdecoded[i * 2]); 717 q->samples[i].im = (q->pre_coef2[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) - 718 (q->pre_coef1[i] * chctx->CWdecoded[i * 2]); 719 } 720 721 /* FFT */ 722 q->fft.fft_permute(&q->fft, q->samples); 723 q->fft.fft_calc(&q->fft, q->samples); 724 725 /* postrotation, window and reorder */ 726 for (i = 0; i < COEFFS / 2; i++) { 727 re = ( q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]); 728 im = (-q->samples[i].im * q->post_cos[i]) - ( q->samples[i].re * q->post_sin[i]); 729 *dst1 = (q->mdct_sine_window[COEFFS - 1 - i * 2] * chctx->last_fft_im[i]) 730 + (q->mdct_sine_window[i * 2] * re); 731 *dst2 = (q->mdct_sine_window[i * 2] * chctx->last_fft_im[i]) 732 - (q->mdct_sine_window[COEFFS - 1 - i * 2] * re); 733 dst1 += 2; 734 dst2 -= 2; 735 chctx->last_fft_im[i] = im; 736 } 737} 738 739static int inverse_quant_coeff(IMCContext *q, IMCChannel *chctx, 740 int stream_format_code) 741{ 742 int i, j; 743 int middle_value, cw_len, max_size; 744 const float *quantizer; 745 746 for (i = 0; i < BANDS; i++) { 747 for (j = band_tab[i]; j < band_tab[i + 1]; j++) { 748 chctx->CWdecoded[j] = 0; 749 cw_len = chctx->CWlengthT[j]; 750 751 if (cw_len <= 0 || chctx->skipFlags[j]) 752 continue; 753 754 max_size = 1 << cw_len; 755 middle_value = max_size >> 1; 756 757 if (chctx->codewords[j] >= max_size || chctx->codewords[j] < 0) 758 return AVERROR_INVALIDDATA; 759 760 if (cw_len >= 4) { 761 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1]; 762 if (chctx->codewords[j] >= middle_value) 763 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 8] * chctx->flcoeffs6[i]; 764 else 765 chctx->CWdecoded[j] = -quantizer[max_size - chctx->codewords[j] - 8 - 1] * chctx->flcoeffs6[i]; 766 }else{ 767 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (chctx->bandFlagsBuf[i] << 1)]; 768 if (chctx->codewords[j] >= middle_value) 769 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 1] * chctx->flcoeffs6[i]; 770 else 771 chctx->CWdecoded[j] = -quantizer[max_size - 2 - chctx->codewords[j]] * chctx->flcoeffs6[i]; 772 } 773 } 774 } 775 return 0; 776} 777 778 779static int imc_get_coeffs(IMCContext *q, IMCChannel *chctx) 780{ 781 int i, j, cw_len, cw; 782 783 for (i = 0; i < BANDS; i++) { 784 if (!chctx->sumLenArr[i]) 785 continue; 786 if (chctx->bandFlagsBuf[i] || chctx->bandWidthT[i]) { 787 for (j = band_tab[i]; j < band_tab[i + 1]; j++) { 788 cw_len = chctx->CWlengthT[j]; 789 cw = 0; 790 791 if (get_bits_count(&q->gb) + cw_len > 512) { 792 av_dlog(NULL, "Band %i coeff %i cw_len %i\n", i, j, cw_len); 793 return AVERROR_INVALIDDATA; 794 } 795 796 if (cw_len && (!chctx->bandFlagsBuf[i] || !chctx->skipFlags[j])) 797 cw = get_bits(&q->gb, cw_len); 798 799 chctx->codewords[j] = cw; 800 } 801 } 802 } 803 return 0; 804} 805 806static void imc_refine_bit_allocation(IMCContext *q, IMCChannel *chctx) 807{ 808 int i, j; 809 int bits, summer; 810 811 for (i = 0; i < BANDS; i++) { 812 chctx->sumLenArr[i] = 0; 813 chctx->skipFlagRaw[i] = 0; 814 for (j = band_tab[i]; j < band_tab[i + 1]; j++) 815 chctx->sumLenArr[i] += chctx->CWlengthT[j]; 816 if (chctx->bandFlagsBuf[i]) 817 if ((((band_tab[i + 1] - band_tab[i]) * 1.5) > chctx->sumLenArr[i]) && (chctx->sumLenArr[i] > 0)) 818 chctx->skipFlagRaw[i] = 1; 819 } 820 821 imc_get_skip_coeff(q, chctx); 822 823 for (i = 0; i < BANDS; i++) { 824 chctx->flcoeffs6[i] = chctx->flcoeffs1[i]; 825 /* band has flag set and at least one coded coefficient */ 826 if (chctx->bandFlagsBuf[i] && (band_tab[i + 1] - band_tab[i]) != chctx->skipFlagCount[i]) { 827 chctx->flcoeffs6[i] *= q->sqrt_tab[ band_tab[i + 1] - band_tab[i]] / 828 q->sqrt_tab[(band_tab[i + 1] - band_tab[i] - chctx->skipFlagCount[i])]; 829 } 830 } 831 832 /* calculate bits left, bits needed and adjust bit allocation */ 833 bits = summer = 0; 834 835 for (i = 0; i < BANDS; i++) { 836 if (chctx->bandFlagsBuf[i]) { 837 for (j = band_tab[i]; j < band_tab[i + 1]; j++) { 838 if (chctx->skipFlags[j]) { 839 summer += chctx->CWlengthT[j]; 840 chctx->CWlengthT[j] = 0; 841 } 842 } 843 bits += chctx->skipFlagBits[i]; 844 summer -= chctx->skipFlagBits[i]; 845 } 846 } 847 imc_adjust_bit_allocation(q, chctx, summer); 848} 849 850static int imc_decode_block(AVCodecContext *avctx, IMCContext *q, int ch) 851{ 852 int stream_format_code; 853 int imc_hdr, i, j, ret; 854 int flag; 855 int bits; 856 int counter, bitscount; 857 IMCChannel *chctx = q->chctx + ch; 858 859 860 /* Check the frame header */ 861 imc_hdr = get_bits(&q->gb, 9); 862 if (imc_hdr & 0x18) { 863 av_log(avctx, AV_LOG_ERROR, "frame header check failed!\n"); 864 av_log(avctx, AV_LOG_ERROR, "got %X.\n", imc_hdr); 865 return AVERROR_INVALIDDATA; 866 } 867 stream_format_code = get_bits(&q->gb, 3); 868 869 if (stream_format_code & 0x04) 870 chctx->decoder_reset = 1; 871 872 if (chctx->decoder_reset) { 873 for (i = 0; i < BANDS; i++) 874 chctx->old_floor[i] = 1.0; 875 for (i = 0; i < COEFFS; i++) 876 chctx->CWdecoded[i] = 0; 877 chctx->decoder_reset = 0; 878 } 879 880 flag = get_bits1(&q->gb); 881 if (stream_format_code & 0x1) 882 imc_decode_level_coefficients_raw(q, chctx->levlCoeffBuf, 883 chctx->flcoeffs1, chctx->flcoeffs2); 884 else if (stream_format_code & 0x1) 885 imc_read_level_coeffs_raw(q, stream_format_code, chctx->levlCoeffBuf); 886 else 887 imc_read_level_coeffs(q, stream_format_code, chctx->levlCoeffBuf); 888 889 if (stream_format_code & 0x4) 890 imc_decode_level_coefficients(q, chctx->levlCoeffBuf, 891 chctx->flcoeffs1, chctx->flcoeffs2); 892 else 893 imc_decode_level_coefficients2(q, chctx->levlCoeffBuf, chctx->old_floor, 894 chctx->flcoeffs1, chctx->flcoeffs2); 895 896 for(i=0; i<BANDS; i++) { 897 if(chctx->flcoeffs1[i] > INT_MAX) { 898 av_log(avctx, AV_LOG_ERROR, "scalefactor out of range\n"); 899 return AVERROR_INVALIDDATA; 900 } 901 } 902 903 memcpy(chctx->old_floor, chctx->flcoeffs1, 32 * sizeof(float)); 904 905 counter = 0; 906 if (stream_format_code & 0x1) { 907 for (i = 0; i < BANDS; i++) { 908 chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i]; 909 chctx->bandFlagsBuf[i] = 0; 910 chctx->flcoeffs3[i] = chctx->flcoeffs2[i] * 2; 911 chctx->flcoeffs5[i] = 1.0; 912 } 913 } else { 914 for (i = 0; i < BANDS; i++) { 915 if (chctx->levlCoeffBuf[i] == 16) { 916 chctx->bandWidthT[i] = 0; 917 counter++; 918 } else 919 chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i]; 920 } 921 922 memset(chctx->bandFlagsBuf, 0, BANDS * sizeof(int)); 923 for (i = 0; i < BANDS - 1; i++) 924 if (chctx->bandWidthT[i]) 925 chctx->bandFlagsBuf[i] = get_bits1(&q->gb); 926 927 imc_calculate_coeffs(q, chctx->flcoeffs1, chctx->flcoeffs2, 928 chctx->bandWidthT, chctx->flcoeffs3, 929 chctx->flcoeffs5); 930 } 931 932 bitscount = 0; 933 /* first 4 bands will be assigned 5 bits per coefficient */ 934 if (stream_format_code & 0x2) { 935 bitscount += 15; 936 937 chctx->bitsBandT[0] = 5; 938 chctx->CWlengthT[0] = 5; 939 chctx->CWlengthT[1] = 5; 940 chctx->CWlengthT[2] = 5; 941 for (i = 1; i < 4; i++) { 942 if (stream_format_code & 0x1) 943 bits = 5; 944 else 945 bits = (chctx->levlCoeffBuf[i] == 16) ? 0 : 5; 946 chctx->bitsBandT[i] = bits; 947 for (j = band_tab[i]; j < band_tab[i + 1]; j++) { 948 chctx->CWlengthT[j] = bits; 949 bitscount += bits; 950 } 951 } 952 } 953 if (avctx->codec_id == AV_CODEC_ID_IAC) { 954 bitscount += !!chctx->bandWidthT[BANDS - 1]; 955 if (!(stream_format_code & 0x2)) 956 bitscount += 16; 957 } 958 959 if ((ret = bit_allocation(q, chctx, stream_format_code, 960 512 - bitscount - get_bits_count(&q->gb), 961 flag)) < 0) { 962 av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n"); 963 chctx->decoder_reset = 1; 964 return ret; 965 } 966 967 if (stream_format_code & 0x1) { 968 for (i = 0; i < BANDS; i++) 969 chctx->skipFlags[i] = 0; 970 } else { 971 imc_refine_bit_allocation(q, chctx); 972 } 973 974 for (i = 0; i < BANDS; i++) { 975 chctx->sumLenArr[i] = 0; 976 977 for (j = band_tab[i]; j < band_tab[i + 1]; j++) 978 if (!chctx->skipFlags[j]) 979 chctx->sumLenArr[i] += chctx->CWlengthT[j]; 980 } 981 982 memset(chctx->codewords, 0, sizeof(chctx->codewords)); 983 984 if (imc_get_coeffs(q, chctx) < 0) { 985 av_log(avctx, AV_LOG_ERROR, "Read coefficients failed\n"); 986 chctx->decoder_reset = 1; 987 return AVERROR_INVALIDDATA; 988 } 989 990 if (inverse_quant_coeff(q, chctx, stream_format_code) < 0) { 991 av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n"); 992 chctx->decoder_reset = 1; 993 return AVERROR_INVALIDDATA; 994 } 995 996 memset(chctx->skipFlags, 0, sizeof(chctx->skipFlags)); 997 998 imc_imdct256(q, chctx, avctx->channels); 999 1000 return 0; 1001} 1002 1003static int imc_decode_frame(AVCodecContext *avctx, void *data, 1004 int *got_frame_ptr, AVPacket *avpkt) 1005{ 1006 AVFrame *frame = data; 1007 const uint8_t *buf = avpkt->data; 1008 int buf_size = avpkt->size; 1009 int ret, i; 1010 1011 IMCContext *q = avctx->priv_data; 1012 1013 LOCAL_ALIGNED_16(uint16_t, buf16, [IMC_BLOCK_SIZE / 2]); 1014 1015 if (buf_size < IMC_BLOCK_SIZE * avctx->channels) { 1016 av_log(avctx, AV_LOG_ERROR, "frame too small!\n"); 1017 return AVERROR_INVALIDDATA; 1018 } 1019 1020 /* get output buffer */ 1021 frame->nb_samples = COEFFS; 1022 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) 1023 return ret; 1024 1025 for (i = 0; i < avctx->channels; i++) { 1026 q->out_samples = (float *)frame->extended_data[i]; 1027 1028 q->bdsp.bswap16_buf(buf16, (const uint16_t *) buf, IMC_BLOCK_SIZE / 2); 1029 1030 init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8); 1031 1032 buf += IMC_BLOCK_SIZE; 1033 1034 if ((ret = imc_decode_block(avctx, q, i)) < 0) 1035 return ret; 1036 } 1037 1038 if (avctx->channels == 2) { 1039 q->fdsp.butterflies_float((float *)frame->extended_data[0], 1040 (float *)frame->extended_data[1], COEFFS); 1041 } 1042 1043 *got_frame_ptr = 1; 1044 1045 return IMC_BLOCK_SIZE * avctx->channels; 1046} 1047 1048 1049static av_cold int imc_decode_close(AVCodecContext * avctx) 1050{ 1051 IMCContext *q = avctx->priv_data; 1052 1053 ff_fft_end(&q->fft); 1054 1055 return 0; 1056} 1057 1058static av_cold void flush(AVCodecContext *avctx) 1059{ 1060 IMCContext *q = avctx->priv_data; 1061 1062 q->chctx[0].decoder_reset = 1063 q->chctx[1].decoder_reset = 1; 1064} 1065 1066#if CONFIG_IMC_DECODER 1067AVCodec ff_imc_decoder = { 1068 .name = "imc", 1069 .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"), 1070 .type = AVMEDIA_TYPE_AUDIO, 1071 .id = AV_CODEC_ID_IMC, 1072 .priv_data_size = sizeof(IMCContext), 1073 .init = imc_decode_init, 1074 .close = imc_decode_close, 1075 .decode = imc_decode_frame, 1076 .flush = flush, 1077 .capabilities = CODEC_CAP_DR1, 1078 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP, 1079 AV_SAMPLE_FMT_NONE }, 1080}; 1081#endif 1082#if CONFIG_IAC_DECODER 1083AVCodec ff_iac_decoder = { 1084 .name = "iac", 1085 .long_name = NULL_IF_CONFIG_SMALL("IAC (Indeo Audio Coder)"), 1086 .type = AVMEDIA_TYPE_AUDIO, 1087 .id = AV_CODEC_ID_IAC, 1088 .priv_data_size = sizeof(IMCContext), 1089 .init = imc_decode_init, 1090 .close = imc_decode_close, 1091 .decode = imc_decode_frame, 1092 .flush = flush, 1093 .capabilities = CODEC_CAP_DR1, 1094 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP, 1095 AV_SAMPLE_FMT_NONE }, 1096}; 1097#endif 1098