1/* 2 * RealAudio Lossless decoder 3 * 4 * Copyright (c) 2012 Konstantin Shishkov 5 * 6 * This file is part of FFmpeg. 7 * 8 * FFmpeg is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU Lesser General Public 10 * License as published by the Free Software Foundation; either 11 * version 2.1 of the License, or (at your option) any later version. 12 * 13 * FFmpeg is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 16 * Lesser General Public License for more details. 17 * 18 * You should have received a copy of the GNU Lesser General Public 19 * License along with FFmpeg; if not, write to the Free Software 20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 21 */ 22 23/** 24 * @file 25 * This is a decoder for Real Audio Lossless format. 26 * Dedicated to the mastermind behind it, Ralph Wiggum. 27 */ 28 29#include "libavutil/attributes.h" 30#include "libavutil/channel_layout.h" 31#include "avcodec.h" 32#include "codec_internal.h" 33#include "get_bits.h" 34#include "golomb.h" 35#include "internal.h" 36#include "unary.h" 37#include "ralfdata.h" 38 39#define FILTER_NONE 0 40#define FILTER_RAW 642 41 42typedef struct VLCSet { 43 VLC filter_params; 44 VLC bias; 45 VLC coding_mode; 46 VLC filter_coeffs[10][11]; 47 VLC short_codes[15]; 48 VLC long_codes[125]; 49} VLCSet; 50 51#define RALF_MAX_PKT_SIZE 8192 52 53typedef struct RALFContext { 54 int version; 55 int max_frame_size; 56 VLCSet sets[3]; 57 int32_t channel_data[2][4096]; 58 59 int filter_params; ///< combined filter parameters for the current channel data 60 int filter_length; ///< length of the filter for the current channel data 61 int filter_bits; ///< filter precision for the current channel data 62 int32_t filter[64]; 63 64 unsigned bias[2]; ///< a constant value added to channel data after filtering 65 66 int num_blocks; ///< number of blocks inside the frame 67 int sample_offset; 68 int block_size[1 << 12]; ///< size of the blocks 69 int block_pts[1 << 12]; ///< block start time (in milliseconds) 70 71 uint8_t pkt[16384]; 72 int has_pkt; 73} RALFContext; 74 75#define MAX_ELEMS 644 // no RALF table uses more than that 76 77static av_cold int init_ralf_vlc(VLC *vlc, const uint8_t *data, int elems) 78{ 79 uint8_t lens[MAX_ELEMS]; 80 uint16_t codes[MAX_ELEMS]; 81 int counts[17], prefixes[18]; 82 int i, cur_len; 83 int max_bits = 0; 84 int nb = 0; 85 86 for (i = 0; i <= 16; i++) 87 counts[i] = 0; 88 for (i = 0; i < elems; i++) { 89 cur_len = (nb ? *data & 0xF : *data >> 4) + 1; 90 counts[cur_len]++; 91 max_bits = FFMAX(max_bits, cur_len); 92 lens[i] = cur_len; 93 data += nb; 94 nb ^= 1; 95 } 96 prefixes[1] = 0; 97 for (i = 1; i <= 16; i++) 98 prefixes[i + 1] = (prefixes[i] + counts[i]) << 1; 99 100 for (i = 0; i < elems; i++) 101 codes[i] = prefixes[lens[i]]++; 102 103 return ff_init_vlc_sparse(vlc, FFMIN(max_bits, 9), elems, 104 lens, 1, 1, codes, 2, 2, NULL, 0, 0, 0); 105} 106 107static av_cold int decode_close(AVCodecContext *avctx) 108{ 109 RALFContext *ctx = avctx->priv_data; 110 int i, j, k; 111 112 for (i = 0; i < 3; i++) { 113 ff_free_vlc(&ctx->sets[i].filter_params); 114 ff_free_vlc(&ctx->sets[i].bias); 115 ff_free_vlc(&ctx->sets[i].coding_mode); 116 for (j = 0; j < 10; j++) 117 for (k = 0; k < 11; k++) 118 ff_free_vlc(&ctx->sets[i].filter_coeffs[j][k]); 119 for (j = 0; j < 15; j++) 120 ff_free_vlc(&ctx->sets[i].short_codes[j]); 121 for (j = 0; j < 125; j++) 122 ff_free_vlc(&ctx->sets[i].long_codes[j]); 123 } 124 125 return 0; 126} 127 128static av_cold int decode_init(AVCodecContext *avctx) 129{ 130 RALFContext *ctx = avctx->priv_data; 131 int i, j, k; 132 int ret, channels; 133 134 if (avctx->extradata_size < 24 || memcmp(avctx->extradata, "LSD:", 4)) { 135 av_log(avctx, AV_LOG_ERROR, "Extradata is not groovy, dude\n"); 136 return AVERROR_INVALIDDATA; 137 } 138 139 ctx->version = AV_RB16(avctx->extradata + 4); 140 if (ctx->version != 0x103) { 141 avpriv_request_sample(avctx, "Unknown version %X", ctx->version); 142 return AVERROR_PATCHWELCOME; 143 } 144 145 channels = AV_RB16(avctx->extradata + 8); 146 avctx->sample_rate = AV_RB32(avctx->extradata + 12); 147 if (channels < 1 || channels > 2 148 || avctx->sample_rate < 8000 || avctx->sample_rate > 96000) { 149 av_log(avctx, AV_LOG_ERROR, "Invalid coding parameters %d Hz %d ch\n", 150 avctx->sample_rate, channels); 151 return AVERROR_INVALIDDATA; 152 } 153 avctx->sample_fmt = AV_SAMPLE_FMT_S16P; 154 av_channel_layout_uninit(&avctx->ch_layout); 155 av_channel_layout_default(&avctx->ch_layout, channels); 156 157 ctx->max_frame_size = AV_RB32(avctx->extradata + 16); 158 if (ctx->max_frame_size > (1 << 20) || !ctx->max_frame_size) { 159 av_log(avctx, AV_LOG_ERROR, "invalid frame size %d\n", 160 ctx->max_frame_size); 161 } 162 ctx->max_frame_size = FFMAX(ctx->max_frame_size, avctx->sample_rate); 163 164 for (i = 0; i < 3; i++) { 165 ret = init_ralf_vlc(&ctx->sets[i].filter_params, filter_param_def[i], 166 FILTERPARAM_ELEMENTS); 167 if (ret < 0) 168 return ret; 169 ret = init_ralf_vlc(&ctx->sets[i].bias, bias_def[i], BIAS_ELEMENTS); 170 if (ret < 0) 171 return ret; 172 ret = init_ralf_vlc(&ctx->sets[i].coding_mode, coding_mode_def[i], 173 CODING_MODE_ELEMENTS); 174 if (ret < 0) 175 return ret; 176 for (j = 0; j < 10; j++) { 177 for (k = 0; k < 11; k++) { 178 ret = init_ralf_vlc(&ctx->sets[i].filter_coeffs[j][k], 179 filter_coeffs_def[i][j][k], 180 FILTER_COEFFS_ELEMENTS); 181 if (ret < 0) 182 return ret; 183 } 184 } 185 for (j = 0; j < 15; j++) { 186 ret = init_ralf_vlc(&ctx->sets[i].short_codes[j], 187 short_codes_def[i][j], SHORT_CODES_ELEMENTS); 188 if (ret < 0) 189 return ret; 190 } 191 for (j = 0; j < 125; j++) { 192 ret = init_ralf_vlc(&ctx->sets[i].long_codes[j], 193 long_codes_def[i][j], LONG_CODES_ELEMENTS); 194 if (ret < 0) 195 return ret; 196 } 197 } 198 199 return 0; 200} 201 202static inline int extend_code(GetBitContext *gb, int val, int range, int bits) 203{ 204 if (val == 0) { 205 val = -range - get_ue_golomb(gb); 206 } else if (val == range * 2) { 207 val = range + get_ue_golomb(gb); 208 } else { 209 val -= range; 210 } 211 if (bits) 212 val = ((unsigned)val << bits) | get_bits(gb, bits); 213 return val; 214} 215 216static int decode_channel(RALFContext *ctx, GetBitContext *gb, int ch, 217 int length, int mode, int bits) 218{ 219 int i, t; 220 int code_params; 221 VLCSet *set = ctx->sets + mode; 222 VLC *code_vlc; int range, range2, add_bits; 223 int *dst = ctx->channel_data[ch]; 224 225 ctx->filter_params = get_vlc2(gb, set->filter_params.table, 9, 2); 226 if (ctx->filter_params > 1) { 227 ctx->filter_bits = (ctx->filter_params - 2) >> 6; 228 ctx->filter_length = ctx->filter_params - (ctx->filter_bits << 6) - 1; 229 } 230 231 if (ctx->filter_params == FILTER_RAW) { 232 for (i = 0; i < length; i++) 233 dst[i] = get_bits(gb, bits); 234 ctx->bias[ch] = 0; 235 return 0; 236 } 237 238 ctx->bias[ch] = get_vlc2(gb, set->bias.table, 9, 2); 239 ctx->bias[ch] = extend_code(gb, ctx->bias[ch], 127, 4); 240 241 if (ctx->filter_params == FILTER_NONE) { 242 memset(dst, 0, sizeof(*dst) * length); 243 return 0; 244 } 245 246 if (ctx->filter_params > 1) { 247 int cmode = 0, coeff = 0; 248 VLC *vlc = set->filter_coeffs[ctx->filter_bits] + 5; 249 250 add_bits = ctx->filter_bits; 251 252 for (i = 0; i < ctx->filter_length; i++) { 253 t = get_vlc2(gb, vlc[cmode].table, vlc[cmode].bits, 2); 254 t = extend_code(gb, t, 21, add_bits); 255 if (!cmode) 256 coeff -= 12U << add_bits; 257 coeff = (unsigned)t - coeff; 258 ctx->filter[i] = coeff; 259 260 cmode = coeff >> add_bits; 261 if (cmode < 0) { 262 cmode = -1 - av_log2(-cmode); 263 if (cmode < -5) 264 cmode = -5; 265 } else if (cmode > 0) { 266 cmode = 1 + av_log2(cmode); 267 if (cmode > 5) 268 cmode = 5; 269 } 270 } 271 } 272 273 code_params = get_vlc2(gb, set->coding_mode.table, set->coding_mode.bits, 2); 274 if (code_params >= 15) { 275 add_bits = av_clip((code_params / 5 - 3) / 2, 0, 10); 276 if (add_bits > 9 && (code_params % 5) != 2) 277 add_bits--; 278 range = 10; 279 range2 = 21; 280 code_vlc = set->long_codes + (code_params - 15); 281 } else { 282 add_bits = 0; 283 range = 6; 284 range2 = 13; 285 code_vlc = set->short_codes + code_params; 286 } 287 288 for (i = 0; i < length; i += 2) { 289 int code1, code2; 290 291 t = get_vlc2(gb, code_vlc->table, code_vlc->bits, 2); 292 code1 = t / range2; 293 code2 = t % range2; 294 dst[i] = extend_code(gb, code1, range, 0) * (1U << add_bits); 295 dst[i + 1] = extend_code(gb, code2, range, 0) * (1U << add_bits); 296 if (add_bits) { 297 dst[i] |= get_bits(gb, add_bits); 298 dst[i + 1] |= get_bits(gb, add_bits); 299 } 300 } 301 302 return 0; 303} 304 305static void apply_lpc(RALFContext *ctx, int ch, int length, int bits) 306{ 307 int i, j, acc; 308 int *audio = ctx->channel_data[ch]; 309 int bias = 1 << (ctx->filter_bits - 1); 310 int max_clip = (1 << bits) - 1, min_clip = -max_clip - 1; 311 312 for (i = 1; i < length; i++) { 313 int flen = FFMIN(ctx->filter_length, i); 314 315 acc = 0; 316 for (j = 0; j < flen; j++) 317 acc += (unsigned)ctx->filter[j] * audio[i - j - 1]; 318 if (acc < 0) { 319 acc = (acc + bias - 1) >> ctx->filter_bits; 320 acc = FFMAX(acc, min_clip); 321 } else { 322 acc = ((unsigned)acc + bias) >> ctx->filter_bits; 323 acc = FFMIN(acc, max_clip); 324 } 325 audio[i] += acc; 326 } 327} 328 329static int decode_block(AVCodecContext *avctx, GetBitContext *gb, 330 int16_t *dst0, int16_t *dst1) 331{ 332 RALFContext *ctx = avctx->priv_data; 333 int len, ch, ret; 334 int dmode, mode[2], bits[2]; 335 int *ch0, *ch1; 336 int i; 337 unsigned int t, t2; 338 339 len = 12 - get_unary(gb, 0, 6); 340 341 if (len <= 7) len ^= 1; // codes for length = 6 and 7 are swapped 342 len = 1 << len; 343 344 if (ctx->sample_offset + len > ctx->max_frame_size) { 345 av_log(avctx, AV_LOG_ERROR, 346 "Decoder's stomach is crying, it ate too many samples\n"); 347 return AVERROR_INVALIDDATA; 348 } 349 350 if (avctx->ch_layout.nb_channels > 1) 351 dmode = get_bits(gb, 2) + 1; 352 else 353 dmode = 0; 354 355 mode[0] = (dmode == 4) ? 1 : 0; 356 mode[1] = (dmode >= 2) ? 2 : 0; 357 bits[0] = 16; 358 bits[1] = (mode[1] == 2) ? 17 : 16; 359 360 for (ch = 0; ch < avctx->ch_layout.nb_channels; ch++) { 361 if ((ret = decode_channel(ctx, gb, ch, len, mode[ch], bits[ch])) < 0) 362 return ret; 363 if (ctx->filter_params > 1 && ctx->filter_params != FILTER_RAW) { 364 ctx->filter_bits += 3; 365 apply_lpc(ctx, ch, len, bits[ch]); 366 } 367 if (get_bits_left(gb) < 0) 368 return AVERROR_INVALIDDATA; 369 } 370 ch0 = ctx->channel_data[0]; 371 ch1 = ctx->channel_data[1]; 372 switch (dmode) { 373 case 0: 374 for (i = 0; i < len; i++) 375 dst0[i] = ch0[i] + ctx->bias[0]; 376 break; 377 case 1: 378 for (i = 0; i < len; i++) { 379 dst0[i] = ch0[i] + ctx->bias[0]; 380 dst1[i] = ch1[i] + ctx->bias[1]; 381 } 382 break; 383 case 2: 384 for (i = 0; i < len; i++) { 385 ch0[i] += ctx->bias[0]; 386 dst0[i] = ch0[i]; 387 dst1[i] = ch0[i] - (ch1[i] + ctx->bias[1]); 388 } 389 break; 390 case 3: 391 for (i = 0; i < len; i++) { 392 t = ch0[i] + ctx->bias[0]; 393 t2 = ch1[i] + ctx->bias[1]; 394 dst0[i] = t + t2; 395 dst1[i] = t; 396 } 397 break; 398 case 4: 399 for (i = 0; i < len; i++) { 400 t = ch1[i] + ctx->bias[1]; 401 t2 = ((ch0[i] + ctx->bias[0]) * 2) | (t & 1); 402 dst0[i] = (int)(t2 + t) / 2; 403 dst1[i] = (int)(t2 - t) / 2; 404 } 405 break; 406 } 407 408 ctx->sample_offset += len; 409 410 return 0; 411} 412 413static int decode_frame(AVCodecContext *avctx, AVFrame *frame, 414 int *got_frame_ptr, AVPacket *avpkt) 415{ 416 RALFContext *ctx = avctx->priv_data; 417 int16_t *samples0; 418 int16_t *samples1; 419 int ret; 420 GetBitContext gb; 421 int table_size, table_bytes, i; 422 const uint8_t *src, *block_pointer; 423 int src_size; 424 int bytes_left; 425 426 if (ctx->has_pkt) { 427 ctx->has_pkt = 0; 428 table_bytes = (AV_RB16(avpkt->data) + 7) >> 3; 429 if (table_bytes + 3 > avpkt->size || avpkt->size > RALF_MAX_PKT_SIZE) { 430 av_log(avctx, AV_LOG_ERROR, "Wrong packet's breath smells of wrong data!\n"); 431 return AVERROR_INVALIDDATA; 432 } 433 if (memcmp(ctx->pkt, avpkt->data, 2 + table_bytes)) { 434 av_log(avctx, AV_LOG_ERROR, "Wrong packet tails are wrong!\n"); 435 return AVERROR_INVALIDDATA; 436 } 437 438 src = ctx->pkt; 439 src_size = RALF_MAX_PKT_SIZE + avpkt->size; 440 memcpy(ctx->pkt + RALF_MAX_PKT_SIZE, avpkt->data + 2 + table_bytes, 441 avpkt->size - 2 - table_bytes); 442 } else { 443 if (avpkt->size == RALF_MAX_PKT_SIZE) { 444 memcpy(ctx->pkt, avpkt->data, avpkt->size); 445 ctx->has_pkt = 1; 446 *got_frame_ptr = 0; 447 448 return avpkt->size; 449 } 450 src = avpkt->data; 451 src_size = avpkt->size; 452 } 453 454 frame->nb_samples = ctx->max_frame_size; 455 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) 456 return ret; 457 samples0 = (int16_t *)frame->data[0]; 458 samples1 = (int16_t *)frame->data[1]; 459 460 if (src_size < 5) { 461 av_log(avctx, AV_LOG_ERROR, "too short packets are too short!\n"); 462 return AVERROR_INVALIDDATA; 463 } 464 table_size = AV_RB16(src); 465 table_bytes = (table_size + 7) >> 3; 466 if (src_size < table_bytes + 3) { 467 av_log(avctx, AV_LOG_ERROR, "short packets are short!\n"); 468 return AVERROR_INVALIDDATA; 469 } 470 init_get_bits(&gb, src + 2, table_size); 471 ctx->num_blocks = 0; 472 while (get_bits_left(&gb) > 0) { 473 if (ctx->num_blocks >= FF_ARRAY_ELEMS(ctx->block_size)) 474 return AVERROR_INVALIDDATA; 475 ctx->block_size[ctx->num_blocks] = get_bits(&gb, 13 + avctx->ch_layout.nb_channels); 476 if (get_bits1(&gb)) { 477 ctx->block_pts[ctx->num_blocks] = get_bits(&gb, 9); 478 } else { 479 ctx->block_pts[ctx->num_blocks] = 0; 480 } 481 ctx->num_blocks++; 482 } 483 484 block_pointer = src + table_bytes + 2; 485 bytes_left = src_size - table_bytes - 2; 486 ctx->sample_offset = 0; 487 for (i = 0; i < ctx->num_blocks; i++) { 488 if (bytes_left < ctx->block_size[i]) { 489 av_log(avctx, AV_LOG_ERROR, "I'm pedaling backwards\n"); 490 break; 491 } 492 init_get_bits(&gb, block_pointer, ctx->block_size[i] * 8); 493 if (decode_block(avctx, &gb, samples0 + ctx->sample_offset, 494 samples1 + ctx->sample_offset) < 0) { 495 av_log(avctx, AV_LOG_ERROR, "Sir, I got carsick in your office. Not decoding the rest of packet.\n"); 496 break; 497 } 498 block_pointer += ctx->block_size[i]; 499 bytes_left -= ctx->block_size[i]; 500 } 501 502 frame->nb_samples = ctx->sample_offset; 503 *got_frame_ptr = ctx->sample_offset > 0; 504 505 return avpkt->size; 506} 507 508static void decode_flush(AVCodecContext *avctx) 509{ 510 RALFContext *ctx = avctx->priv_data; 511 512 ctx->has_pkt = 0; 513} 514 515 516const FFCodec ff_ralf_decoder = { 517 .p.name = "ralf", 518 .p.long_name = NULL_IF_CONFIG_SMALL("RealAudio Lossless"), 519 .p.type = AVMEDIA_TYPE_AUDIO, 520 .p.id = AV_CODEC_ID_RALF, 521 .priv_data_size = sizeof(RALFContext), 522 .init = decode_init, 523 .close = decode_close, 524 FF_CODEC_DECODE_CB(decode_frame), 525 .flush = decode_flush, 526 .p.capabilities = AV_CODEC_CAP_CHANNEL_CONF | 527 AV_CODEC_CAP_DR1, 528 .p.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P, 529 AV_SAMPLE_FMT_NONE }, 530 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP, 531}; 532