| 1 | /* |
| 2 | * MLP parser |
| 3 | * Copyright (c) 2007 Ian Caulfield |
| 4 | * |
| 5 | * This file is part of FFmpeg. |
| 6 | * |
| 7 | * FFmpeg is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU Lesser General Public |
| 9 | * License as published by the Free Software Foundation; either |
| 10 | * version 2.1 of the License, or (at your option) any later version. |
| 11 | * |
| 12 | * FFmpeg is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 15 | * Lesser General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU Lesser General Public |
| 18 | * License along with FFmpeg; if not, write to the Free Software |
| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 20 | */ |
| 21 | |
| 22 | /** |
| 23 | * @file |
| 24 | * MLP parser |
| 25 | */ |
| 26 | |
| 27 | #include <stdint.h> |
| 28 | |
| 29 | #include "libavutil/channel_layout.h" |
| 30 | #include "libavutil/crc.h" |
| 31 | #include "libavutil/internal.h" |
| 32 | #include "get_bits.h" |
| 33 | #include "parser.h" |
| 34 | #include "mlp_parser.h" |
| 35 | #include "mlp.h" |
| 36 | |
| 37 | static const uint8_t mlp_quants[16] = { |
| 38 | 16, 20, 24, 0, 0, 0, 0, 0, |
| 39 | 0, 0, 0, 0, 0, 0, 0, 0, |
| 40 | }; |
| 41 | |
| 42 | static const uint8_t mlp_channels[32] = { |
| 43 | 1, 2, 3, 4, 3, 4, 5, 3, 4, 5, 4, 5, 6, 4, 5, 4, |
| 44 | 5, 6, 5, 5, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
| 45 | }; |
| 46 | |
| 47 | const uint64_t ff_mlp_layout[32] = { |
| 48 | AV_CH_LAYOUT_MONO, |
| 49 | AV_CH_LAYOUT_STEREO, |
| 50 | AV_CH_LAYOUT_2_1, |
| 51 | AV_CH_LAYOUT_QUAD, |
| 52 | AV_CH_LAYOUT_STEREO|AV_CH_LOW_FREQUENCY, |
| 53 | AV_CH_LAYOUT_2_1|AV_CH_LOW_FREQUENCY, |
| 54 | AV_CH_LAYOUT_QUAD|AV_CH_LOW_FREQUENCY, |
| 55 | AV_CH_LAYOUT_SURROUND, |
| 56 | AV_CH_LAYOUT_4POINT0, |
| 57 | AV_CH_LAYOUT_5POINT0_BACK, |
| 58 | AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY, |
| 59 | AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY, |
| 60 | AV_CH_LAYOUT_5POINT1_BACK, |
| 61 | AV_CH_LAYOUT_4POINT0, |
| 62 | AV_CH_LAYOUT_5POINT0_BACK, |
| 63 | AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY, |
| 64 | AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY, |
| 65 | AV_CH_LAYOUT_5POINT1_BACK, |
| 66 | AV_CH_LAYOUT_QUAD|AV_CH_LOW_FREQUENCY, |
| 67 | AV_CH_LAYOUT_5POINT0_BACK, |
| 68 | AV_CH_LAYOUT_5POINT1_BACK, |
| 69 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 |
| 70 | }; |
| 71 | |
| 72 | static const uint8_t thd_chancount[13] = { |
| 73 | // LR C LFE LRs LRvh LRc LRrs Cs Ts LRsd LRw Cvh LFE2 |
| 74 | 2, 1, 1, 2, 2, 2, 2, 1, 1, 2, 2, 1, 1 |
| 75 | }; |
| 76 | |
| 77 | static const uint64_t thd_layout[13] = { |
| 78 | AV_CH_FRONT_LEFT|AV_CH_FRONT_RIGHT, // LR |
| 79 | AV_CH_FRONT_CENTER, // C |
| 80 | AV_CH_LOW_FREQUENCY, // LFE |
| 81 | AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT, // LRs |
| 82 | AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT, // LRvh |
| 83 | AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER, // LRc |
| 84 | AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT, // LRrs |
| 85 | AV_CH_BACK_CENTER, // Cs |
| 86 | AV_CH_TOP_CENTER, // Ts |
| 87 | AV_CH_SURROUND_DIRECT_LEFT|AV_CH_SURROUND_DIRECT_RIGHT, // LRsd |
| 88 | AV_CH_WIDE_LEFT|AV_CH_WIDE_RIGHT, // LRw |
| 89 | AV_CH_TOP_FRONT_CENTER, // Cvh |
| 90 | AV_CH_LOW_FREQUENCY_2, // LFE2 |
| 91 | }; |
| 92 | |
| 93 | static int mlp_samplerate(int in) |
| 94 | { |
| 95 | if (in == 0xF) |
| 96 | return 0; |
| 97 | |
| 98 | return (in & 8 ? 44100 : 48000) << (in & 7) ; |
| 99 | } |
| 100 | |
| 101 | static int truehd_channels(int chanmap) |
| 102 | { |
| 103 | int channels = 0, i; |
| 104 | |
| 105 | for (i = 0; i < 13; i++) |
| 106 | channels += thd_chancount[i] * ((chanmap >> i) & 1); |
| 107 | |
| 108 | return channels; |
| 109 | } |
| 110 | |
| 111 | uint64_t ff_truehd_layout(int chanmap) |
| 112 | { |
| 113 | int i; |
| 114 | uint64_t layout = 0; |
| 115 | |
| 116 | for (i = 0; i < 13; i++) |
| 117 | layout |= thd_layout[i] * ((chanmap >> i) & 1); |
| 118 | |
| 119 | return layout; |
| 120 | } |
| 121 | |
| 122 | /** Read a major sync info header - contains high level information about |
| 123 | * the stream - sample rate, channel arrangement etc. Most of this |
| 124 | * information is not actually necessary for decoding, only for playback. |
| 125 | * gb must be a freshly initialized GetBitContext with no bits read. |
| 126 | */ |
| 127 | |
| 128 | int ff_mlp_read_major_sync(void *log, MLPHeaderInfo *mh, GetBitContext *gb) |
| 129 | { |
| 130 | int ratebits, channel_arrangement; |
| 131 | uint16_t checksum; |
| 132 | |
| 133 | av_assert1(get_bits_count(gb) == 0); |
| 134 | |
| 135 | if (gb->size_in_bits < 28 << 3) { |
| 136 | av_log(log, AV_LOG_ERROR, "packet too short, unable to read major sync\n"); |
| 137 | return -1; |
| 138 | } |
| 139 | |
| 140 | checksum = ff_mlp_checksum16(gb->buffer, 26); |
| 141 | if (checksum != AV_RL16(gb->buffer+26)) { |
| 142 | av_log(log, AV_LOG_ERROR, "major sync info header checksum error\n"); |
| 143 | return AVERROR_INVALIDDATA; |
| 144 | } |
| 145 | |
| 146 | if (get_bits_long(gb, 24) != 0xf8726f) /* Sync words */ |
| 147 | return AVERROR_INVALIDDATA; |
| 148 | |
| 149 | mh->stream_type = get_bits(gb, 8); |
| 150 | |
| 151 | if (mh->stream_type == 0xbb) { |
| 152 | mh->group1_bits = mlp_quants[get_bits(gb, 4)]; |
| 153 | mh->group2_bits = mlp_quants[get_bits(gb, 4)]; |
| 154 | |
| 155 | ratebits = get_bits(gb, 4); |
| 156 | mh->group1_samplerate = mlp_samplerate(ratebits); |
| 157 | mh->group2_samplerate = mlp_samplerate(get_bits(gb, 4)); |
| 158 | |
| 159 | skip_bits(gb, 11); |
| 160 | |
| 161 | mh->channel_arrangement= |
| 162 | channel_arrangement = get_bits(gb, 5); |
| 163 | mh->channels_mlp = mlp_channels[channel_arrangement]; |
| 164 | mh->channel_layout_mlp = ff_mlp_layout[channel_arrangement]; |
| 165 | } else if (mh->stream_type == 0xba) { |
| 166 | mh->group1_bits = 24; // TODO: Is this information actually conveyed anywhere? |
| 167 | mh->group2_bits = 0; |
| 168 | |
| 169 | ratebits = get_bits(gb, 4); |
| 170 | mh->group1_samplerate = mlp_samplerate(ratebits); |
| 171 | mh->group2_samplerate = 0; |
| 172 | |
| 173 | skip_bits(gb, 4); |
| 174 | |
| 175 | mh->channel_modifier_thd_stream0 = get_bits(gb, 2); |
| 176 | mh->channel_modifier_thd_stream1 = get_bits(gb, 2); |
| 177 | |
| 178 | mh->channel_arrangement= |
| 179 | channel_arrangement = get_bits(gb, 5); |
| 180 | mh->channels_thd_stream1 = truehd_channels(channel_arrangement); |
| 181 | mh->channel_layout_thd_stream1 = ff_truehd_layout(channel_arrangement); |
| 182 | |
| 183 | mh->channel_modifier_thd_stream2 = get_bits(gb, 2); |
| 184 | |
| 185 | channel_arrangement = get_bits(gb, 13); |
| 186 | mh->channels_thd_stream2 = truehd_channels(channel_arrangement); |
| 187 | mh->channel_layout_thd_stream2 = ff_truehd_layout(channel_arrangement); |
| 188 | } else |
| 189 | return AVERROR_INVALIDDATA; |
| 190 | |
| 191 | mh->access_unit_size = 40 << (ratebits & 7); |
| 192 | mh->access_unit_size_pow2 = 64 << (ratebits & 7); |
| 193 | |
| 194 | skip_bits_long(gb, 48); |
| 195 | |
| 196 | mh->is_vbr = get_bits1(gb); |
| 197 | |
| 198 | mh->peak_bitrate = (get_bits(gb, 15) * mh->group1_samplerate + 8) >> 4; |
| 199 | |
| 200 | mh->num_substreams = get_bits(gb, 4); |
| 201 | |
| 202 | skip_bits_long(gb, 4 + 11 * 8); |
| 203 | |
| 204 | return 0; |
| 205 | } |
| 206 | |
| 207 | typedef struct MLPParseContext |
| 208 | { |
| 209 | ParseContext pc; |
| 210 | |
| 211 | int bytes_left; |
| 212 | |
| 213 | int in_sync; |
| 214 | |
| 215 | int num_substreams; |
| 216 | } MLPParseContext; |
| 217 | |
| 218 | static av_cold int mlp_init(AVCodecParserContext *s) |
| 219 | { |
| 220 | ff_mlp_init_crc(); |
| 221 | return 0; |
| 222 | } |
| 223 | |
| 224 | static int mlp_parse(AVCodecParserContext *s, |
| 225 | AVCodecContext *avctx, |
| 226 | const uint8_t **poutbuf, int *poutbuf_size, |
| 227 | const uint8_t *buf, int buf_size) |
| 228 | { |
| 229 | MLPParseContext *mp = s->priv_data; |
| 230 | int sync_present; |
| 231 | uint8_t parity_bits; |
| 232 | int next; |
| 233 | int ret; |
| 234 | int i, p = 0; |
| 235 | |
| 236 | *poutbuf_size = 0; |
| 237 | if (buf_size == 0) |
| 238 | return 0; |
| 239 | |
| 240 | if (!mp->in_sync) { |
| 241 | // Not in sync - find a major sync header |
| 242 | |
| 243 | for (i = 0; i < buf_size; i++) { |
| 244 | mp->pc.state = (mp->pc.state << 8) | buf[i]; |
| 245 | if ((mp->pc.state & 0xfffffffe) == 0xf8726fba && |
| 246 | // ignore if we do not have the data for the start of header |
| 247 | mp->pc.index + i >= 7) { |
| 248 | mp->in_sync = 1; |
| 249 | mp->bytes_left = 0; |
| 250 | break; |
| 251 | } |
| 252 | } |
| 253 | |
| 254 | if (!mp->in_sync) { |
| 255 | if (ff_combine_frame(&mp->pc, END_NOT_FOUND, &buf, &buf_size) != -1) |
| 256 | av_log(avctx, AV_LOG_WARNING, "ff_combine_frame failed\n"); |
| 257 | return buf_size; |
| 258 | } |
| 259 | |
| 260 | if ((ret = ff_combine_frame(&mp->pc, i - 7, &buf, &buf_size)) < 0) { |
| 261 | av_log(avctx, AV_LOG_WARNING, "ff_combine_frame failed\n"); |
| 262 | return ret; |
| 263 | } |
| 264 | |
| 265 | return i - 7; |
| 266 | } |
| 267 | |
| 268 | if (mp->bytes_left == 0) { |
| 269 | // Find length of this packet |
| 270 | |
| 271 | /* Copy overread bytes from last frame into buffer. */ |
| 272 | for(; mp->pc.overread>0; mp->pc.overread--) { |
| 273 | mp->pc.buffer[mp->pc.index++]= mp->pc.buffer[mp->pc.overread_index++]; |
| 274 | } |
| 275 | |
| 276 | if (mp->pc.index + buf_size < 2) { |
| 277 | if (ff_combine_frame(&mp->pc, END_NOT_FOUND, &buf, &buf_size) != -1) |
| 278 | av_log(avctx, AV_LOG_WARNING, "ff_combine_frame failed\n"); |
| 279 | return buf_size; |
| 280 | } |
| 281 | |
| 282 | mp->bytes_left = ((mp->pc.index > 0 ? mp->pc.buffer[0] : buf[0]) << 8) |
| 283 | | (mp->pc.index > 1 ? mp->pc.buffer[1] : buf[1-mp->pc.index]); |
| 284 | mp->bytes_left = (mp->bytes_left & 0xfff) * 2; |
| 285 | if (mp->bytes_left <= 0) { // prevent infinite loop |
| 286 | goto lost_sync; |
| 287 | } |
| 288 | mp->bytes_left -= mp->pc.index; |
| 289 | } |
| 290 | |
| 291 | next = (mp->bytes_left > buf_size) ? END_NOT_FOUND : mp->bytes_left; |
| 292 | |
| 293 | if (ff_combine_frame(&mp->pc, next, &buf, &buf_size) < 0) { |
| 294 | mp->bytes_left -= buf_size; |
| 295 | return buf_size; |
| 296 | } |
| 297 | |
| 298 | mp->bytes_left = 0; |
| 299 | |
| 300 | sync_present = (AV_RB32(buf + 4) & 0xfffffffe) == 0xf8726fba; |
| 301 | |
| 302 | if (!sync_present) { |
| 303 | /* The first nibble of a frame is a parity check of the 4-byte |
| 304 | * access unit header and all the 2- or 4-byte substream headers. */ |
| 305 | // Only check when this isn't a sync frame - syncs have a checksum. |
| 306 | |
| 307 | parity_bits = 0; |
| 308 | for (i = -1; i < mp->num_substreams; i++) { |
| 309 | parity_bits ^= buf[p++]; |
| 310 | parity_bits ^= buf[p++]; |
| 311 | |
| 312 | if (i < 0 || buf[p-2] & 0x80) { |
| 313 | parity_bits ^= buf[p++]; |
| 314 | parity_bits ^= buf[p++]; |
| 315 | } |
| 316 | } |
| 317 | |
| 318 | if ((((parity_bits >> 4) ^ parity_bits) & 0xF) != 0xF) { |
| 319 | av_log(avctx, AV_LOG_INFO, "mlpparse: Parity check failed.\n"); |
| 320 | goto lost_sync; |
| 321 | } |
| 322 | } else { |
| 323 | GetBitContext gb; |
| 324 | MLPHeaderInfo mh; |
| 325 | |
| 326 | init_get_bits(&gb, buf + 4, (buf_size - 4) << 3); |
| 327 | if (ff_mlp_read_major_sync(avctx, &mh, &gb) < 0) |
| 328 | goto lost_sync; |
| 329 | |
| 330 | avctx->bits_per_raw_sample = mh.group1_bits; |
| 331 | if (avctx->bits_per_raw_sample > 16) |
| 332 | avctx->sample_fmt = AV_SAMPLE_FMT_S32; |
| 333 | else |
| 334 | avctx->sample_fmt = AV_SAMPLE_FMT_S16; |
| 335 | avctx->sample_rate = mh.group1_samplerate; |
| 336 | s->duration = mh.access_unit_size; |
| 337 | |
| 338 | if(!avctx->channels || !avctx->channel_layout) { |
| 339 | if (mh.stream_type == 0xbb) { |
| 340 | /* MLP stream */ |
| 341 | #if FF_API_REQUEST_CHANNELS |
| 342 | FF_DISABLE_DEPRECATION_WARNINGS |
| 343 | if (avctx->request_channels > 0 && avctx->request_channels <= 2 && |
| 344 | mh.num_substreams > 1) { |
| 345 | avctx->channels = 2; |
| 346 | avctx->channel_layout = AV_CH_LAYOUT_STEREO; |
| 347 | FF_ENABLE_DEPRECATION_WARNINGS |
| 348 | } else |
| 349 | #endif |
| 350 | if (avctx->request_channel_layout && |
| 351 | (avctx->request_channel_layout & AV_CH_LAYOUT_STEREO) == |
| 352 | avctx->request_channel_layout && |
| 353 | mh.num_substreams > 1) { |
| 354 | avctx->channels = 2; |
| 355 | avctx->channel_layout = AV_CH_LAYOUT_STEREO; |
| 356 | } else { |
| 357 | avctx->channels = mh.channels_mlp; |
| 358 | avctx->channel_layout = mh.channel_layout_mlp; |
| 359 | } |
| 360 | } else { /* mh.stream_type == 0xba */ |
| 361 | /* TrueHD stream */ |
| 362 | #if FF_API_REQUEST_CHANNELS |
| 363 | FF_DISABLE_DEPRECATION_WARNINGS |
| 364 | if (avctx->request_channels > 0 && avctx->request_channels <= 2 && |
| 365 | mh.num_substreams > 1) { |
| 366 | avctx->channels = 2; |
| 367 | avctx->channel_layout = AV_CH_LAYOUT_STEREO; |
| 368 | } else if (avctx->request_channels > 0 && |
| 369 | avctx->request_channels <= mh.channels_thd_stream1) { |
| 370 | avctx->channels = mh.channels_thd_stream1; |
| 371 | avctx->channel_layout = mh.channel_layout_thd_stream1; |
| 372 | FF_ENABLE_DEPRECATION_WARNINGS |
| 373 | } else |
| 374 | #endif |
| 375 | if (avctx->request_channel_layout && |
| 376 | (avctx->request_channel_layout & AV_CH_LAYOUT_STEREO) == |
| 377 | avctx->request_channel_layout && |
| 378 | mh.num_substreams > 1) { |
| 379 | avctx->channels = 2; |
| 380 | avctx->channel_layout = AV_CH_LAYOUT_STEREO; |
| 381 | } else if (!mh.channels_thd_stream2 || |
| 382 | (avctx->request_channel_layout && |
| 383 | (avctx->request_channel_layout & mh.channel_layout_thd_stream1) == |
| 384 | avctx->request_channel_layout)) { |
| 385 | avctx->channels = mh.channels_thd_stream1; |
| 386 | avctx->channel_layout = mh.channel_layout_thd_stream1; |
| 387 | } else { |
| 388 | avctx->channels = mh.channels_thd_stream2; |
| 389 | avctx->channel_layout = mh.channel_layout_thd_stream2; |
| 390 | } |
| 391 | } |
| 392 | } |
| 393 | |
| 394 | if (!mh.is_vbr) /* Stream is CBR */ |
| 395 | avctx->bit_rate = mh.peak_bitrate; |
| 396 | |
| 397 | mp->num_substreams = mh.num_substreams; |
| 398 | } |
| 399 | |
| 400 | *poutbuf = buf; |
| 401 | *poutbuf_size = buf_size; |
| 402 | |
| 403 | return next; |
| 404 | |
| 405 | lost_sync: |
| 406 | mp->in_sync = 0; |
| 407 | return 1; |
| 408 | } |
| 409 | |
| 410 | AVCodecParser ff_mlp_parser = { |
| 411 | .codec_ids = { AV_CODEC_ID_MLP, AV_CODEC_ID_TRUEHD }, |
| 412 | .priv_data_size = sizeof(MLPParseContext), |
| 413 | .parser_init = mlp_init, |
| 414 | .parser_parse = mlp_parse, |
| 415 | .parser_close = ff_parse_close, |
| 416 | }; |