1/* 2 * GXF demuxer. 3 * Copyright (c) 2006 Reimar Doeffinger 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#include "libavutil/common.h" 23#include "avformat.h" 24#include "gxf.h" 25 26struct gxf_stream_info { 27 int64_t first_field; 28 int64_t last_field; 29 AVRational frames_per_second; 30 int32_t fields_per_frame; 31}; 32 33/** 34 * \brief parses a packet header, extracting type and length 35 * \param pb ByteIOContext to read header from 36 * \param type detected packet type is stored here 37 * \param length detected packet length, excluding header is stored here 38 * \return 0 if header not found or contains invalid data, 1 otherwise 39 */ 40static int parse_packet_header(ByteIOContext *pb, GXFPktType *type, int *length) { 41 if (get_be32(pb)) 42 return 0; 43 if (get_byte(pb) != 1) 44 return 0; 45 *type = get_byte(pb); 46 *length = get_be32(pb); 47 if ((*length >> 24) || *length < 16) 48 return 0; 49 *length -= 16; 50 if (get_be32(pb)) 51 return 0; 52 if (get_byte(pb) != 0xe1) 53 return 0; 54 if (get_byte(pb) != 0xe2) 55 return 0; 56 return 1; 57} 58 59/** 60 * \brief check if file starts with a PKT_MAP header 61 */ 62static int gxf_probe(AVProbeData *p) { 63 static const uint8_t startcode[] = {0, 0, 0, 0, 1, 0xbc}; // start with map packet 64 static const uint8_t endcode[] = {0, 0, 0, 0, 0xe1, 0xe2}; 65 if (!memcmp(p->buf, startcode, sizeof(startcode)) && 66 !memcmp(&p->buf[16 - sizeof(endcode)], endcode, sizeof(endcode))) 67 return AVPROBE_SCORE_MAX; 68 return 0; 69} 70 71/** 72 * \brief gets the stream index for the track with the specified id, creates new 73 * stream if not found 74 * \param stream id of stream to find / add 75 * \param format stream format identifier 76 */ 77static int get_sindex(AVFormatContext *s, int id, int format) { 78 int i; 79 AVStream *st = NULL; 80 for (i = 0; i < s->nb_streams; i++) { 81 if (s->streams[i]->id == id) 82 return i; 83 } 84 st = av_new_stream(s, id); 85 if (!st) 86 return AVERROR(ENOMEM); 87 switch (format) { 88 case 3: 89 case 4: 90 st->codec->codec_type = CODEC_TYPE_VIDEO; 91 st->codec->codec_id = CODEC_ID_MJPEG; 92 break; 93 case 13: 94 case 15: 95 st->codec->codec_type = CODEC_TYPE_VIDEO; 96 st->codec->codec_id = CODEC_ID_DVVIDEO; 97 break; 98 case 14: 99 case 16: 100 st->codec->codec_type = CODEC_TYPE_VIDEO; 101 st->codec->codec_id = CODEC_ID_DVVIDEO; 102 break; 103 case 11: 104 case 12: 105 case 20: 106 st->codec->codec_type = CODEC_TYPE_VIDEO; 107 st->codec->codec_id = CODEC_ID_MPEG2VIDEO; 108 st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc. 109 break; 110 case 22: 111 case 23: 112 st->codec->codec_type = CODEC_TYPE_VIDEO; 113 st->codec->codec_id = CODEC_ID_MPEG1VIDEO; 114 st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc. 115 break; 116 case 9: 117 st->codec->codec_type = CODEC_TYPE_AUDIO; 118 st->codec->codec_id = CODEC_ID_PCM_S24LE; 119 st->codec->channels = 1; 120 st->codec->sample_rate = 48000; 121 st->codec->bit_rate = 3 * 1 * 48000 * 8; 122 st->codec->block_align = 3 * 1; 123 st->codec->bits_per_coded_sample = 24; 124 break; 125 case 10: 126 st->codec->codec_type = CODEC_TYPE_AUDIO; 127 st->codec->codec_id = CODEC_ID_PCM_S16LE; 128 st->codec->channels = 1; 129 st->codec->sample_rate = 48000; 130 st->codec->bit_rate = 2 * 1 * 48000 * 8; 131 st->codec->block_align = 2 * 1; 132 st->codec->bits_per_coded_sample = 16; 133 break; 134 case 17: 135 st->codec->codec_type = CODEC_TYPE_AUDIO; 136 st->codec->codec_id = CODEC_ID_AC3; 137 st->codec->channels = 2; 138 st->codec->sample_rate = 48000; 139 break; 140 // timecode tracks: 141 case 7: 142 case 8: 143 case 24: 144 st->codec->codec_type = CODEC_TYPE_DATA; 145 st->codec->codec_id = CODEC_ID_NONE; 146 break; 147 default: 148 st->codec->codec_type = CODEC_TYPE_UNKNOWN; 149 st->codec->codec_id = CODEC_ID_NONE; 150 break; 151 } 152 return s->nb_streams - 1; 153} 154 155/** 156 * \brief filters out interesting tags from material information. 157 * \param len length of tag section, will be adjusted to contain remaining bytes 158 * \param si struct to store collected information into 159 */ 160static void gxf_material_tags(ByteIOContext *pb, int *len, struct gxf_stream_info *si) { 161 si->first_field = AV_NOPTS_VALUE; 162 si->last_field = AV_NOPTS_VALUE; 163 while (*len >= 2) { 164 GXFMatTag tag = get_byte(pb); 165 int tlen = get_byte(pb); 166 *len -= 2; 167 if (tlen > *len) 168 return; 169 *len -= tlen; 170 if (tlen == 4) { 171 uint32_t value = get_be32(pb); 172 if (tag == MAT_FIRST_FIELD) 173 si->first_field = value; 174 else if (tag == MAT_LAST_FIELD) 175 si->last_field = value; 176 } else 177 url_fskip(pb, tlen); 178 } 179} 180 181/** 182 * \brief convert fps tag value to AVRational fps 183 * \param fps fps value from tag 184 * \return fps as AVRational, or 0 / 0 if unknown 185 */ 186static AVRational fps_tag2avr(int32_t fps) { 187 extern const AVRational ff_frame_rate_tab[]; 188 if (fps < 1 || fps > 9) fps = 9; 189 return ff_frame_rate_tab[9 - fps]; // values have opposite order 190} 191 192/** 193 * \brief convert UMF attributes flags to AVRational fps 194 * \param fps fps value from flags 195 * \return fps as AVRational, or 0 / 0 if unknown 196 */ 197static AVRational fps_umf2avr(uint32_t flags) { 198 static const AVRational map[] = {{50, 1}, {60000, 1001}, {24, 1}, 199 {25, 1}, {30000, 1001}}; 200 int idx = av_log2((flags & 0x7c0) >> 6); 201 return map[idx]; 202} 203 204/** 205 * \brief filters out interesting tags from track information. 206 * \param len length of tag section, will be adjusted to contain remaining bytes 207 * \param si struct to store collected information into 208 */ 209static void gxf_track_tags(ByteIOContext *pb, int *len, struct gxf_stream_info *si) { 210 si->frames_per_second = (AVRational){0, 0}; 211 si->fields_per_frame = 0; 212 while (*len >= 2) { 213 GXFTrackTag tag = get_byte(pb); 214 int tlen = get_byte(pb); 215 *len -= 2; 216 if (tlen > *len) 217 return; 218 *len -= tlen; 219 if (tlen == 4) { 220 uint32_t value = get_be32(pb); 221 if (tag == TRACK_FPS) 222 si->frames_per_second = fps_tag2avr(value); 223 else if (tag == TRACK_FPF && (value == 1 || value == 2)) 224 si->fields_per_frame = value; 225 } else 226 url_fskip(pb, tlen); 227 } 228} 229 230/** 231 * \brief read index from FLT packet into stream 0 av_index 232 */ 233static void gxf_read_index(AVFormatContext *s, int pkt_len) { 234 ByteIOContext *pb = s->pb; 235 AVStream *st = s->streams[0]; 236 uint32_t fields_per_map = get_le32(pb); 237 uint32_t map_cnt = get_le32(pb); 238 int i; 239 pkt_len -= 8; 240 if (map_cnt > 1000) { 241 av_log(s, AV_LOG_ERROR, "too many index entries %u (%x)\n", map_cnt, map_cnt); 242 map_cnt = 1000; 243 } 244 if (pkt_len < 4 * map_cnt) { 245 av_log(s, AV_LOG_ERROR, "invalid index length\n"); 246 url_fskip(pb, pkt_len); 247 return; 248 } 249 pkt_len -= 4 * map_cnt; 250 av_add_index_entry(st, 0, 0, 0, 0, 0); 251 for (i = 0; i < map_cnt; i++) 252 av_add_index_entry(st, (uint64_t)get_le32(pb) * 1024, 253 i * (uint64_t)fields_per_map + 1, 0, 0, 0); 254 url_fskip(pb, pkt_len); 255} 256 257static int gxf_header(AVFormatContext *s, AVFormatParameters *ap) { 258 ByteIOContext *pb = s->pb; 259 GXFPktType pkt_type; 260 int map_len; 261 int len; 262 AVRational main_timebase = {0, 0}; 263 struct gxf_stream_info si; 264 int i; 265 if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) { 266 av_log(s, AV_LOG_ERROR, "map packet not found\n"); 267 return 0; 268 } 269 map_len -= 2; 270 if (get_byte(pb) != 0x0e0 || get_byte(pb) != 0xff) { 271 av_log(s, AV_LOG_ERROR, "unknown version or invalid map preamble\n"); 272 return 0; 273 } 274 map_len -= 2; 275 len = get_be16(pb); // length of material data section 276 if (len > map_len) { 277 av_log(s, AV_LOG_ERROR, "material data longer than map data\n"); 278 return 0; 279 } 280 map_len -= len; 281 gxf_material_tags(pb, &len, &si); 282 url_fskip(pb, len); 283 map_len -= 2; 284 len = get_be16(pb); // length of track description 285 if (len > map_len) { 286 av_log(s, AV_LOG_ERROR, "track description longer than map data\n"); 287 return 0; 288 } 289 map_len -= len; 290 while (len > 0) { 291 int track_type, track_id, track_len; 292 AVStream *st; 293 int idx; 294 len -= 4; 295 track_type = get_byte(pb); 296 track_id = get_byte(pb); 297 track_len = get_be16(pb); 298 len -= track_len; 299 gxf_track_tags(pb, &track_len, &si); 300 url_fskip(pb, track_len); 301 if (!(track_type & 0x80)) { 302 av_log(s, AV_LOG_ERROR, "invalid track type %x\n", track_type); 303 continue; 304 } 305 track_type &= 0x7f; 306 if ((track_id & 0xc0) != 0xc0) { 307 av_log(s, AV_LOG_ERROR, "invalid track id %x\n", track_id); 308 continue; 309 } 310 track_id &= 0x3f; 311 idx = get_sindex(s, track_id, track_type); 312 if (idx < 0) continue; 313 st = s->streams[idx]; 314 if (!main_timebase.num || !main_timebase.den) { 315 main_timebase.num = si.frames_per_second.den; 316 main_timebase.den = si.frames_per_second.num * si.fields_per_frame; 317 } 318 st->start_time = si.first_field; 319 if (si.first_field != AV_NOPTS_VALUE && si.last_field != AV_NOPTS_VALUE) 320 st->duration = si.last_field - si.first_field; 321 } 322 if (len < 0) 323 av_log(s, AV_LOG_ERROR, "invalid track description length specified\n"); 324 if (map_len) 325 url_fskip(pb, map_len); 326 if (!parse_packet_header(pb, &pkt_type, &len)) { 327 av_log(s, AV_LOG_ERROR, "sync lost in header\n"); 328 return -1; 329 } 330 if (pkt_type == PKT_FLT) { 331 gxf_read_index(s, len); 332 if (!parse_packet_header(pb, &pkt_type, &len)) { 333 av_log(s, AV_LOG_ERROR, "sync lost in header\n"); 334 return -1; 335 } 336 } 337 if (pkt_type == PKT_UMF) { 338 if (len >= 0x39) { 339 AVRational fps; 340 len -= 0x39; 341 url_fskip(pb, 5); // preamble 342 url_fskip(pb, 0x30); // payload description 343 fps = fps_umf2avr(get_le32(pb)); 344 if (!main_timebase.num || !main_timebase.den) { 345 // this may not always be correct, but simply the best we can get 346 main_timebase.num = fps.den; 347 main_timebase.den = fps.num; 348 } 349 } else 350 av_log(s, AV_LOG_INFO, "UMF packet too short\n"); 351 } else 352 av_log(s, AV_LOG_INFO, "UMF packet missing\n"); 353 url_fskip(pb, len); 354 if (!main_timebase.num || !main_timebase.den) 355 main_timebase = (AVRational){1, 50}; // set some arbitrary fallback 356 for (i = 0; i < s->nb_streams; i++) { 357 AVStream *st = s->streams[i]; 358 av_set_pts_info(st, 32, main_timebase.num, main_timebase.den); 359 } 360 return 0; 361} 362 363#define READ_ONE() \ 364 { \ 365 if (!max_interval-- || url_feof(pb)) \ 366 goto out; \ 367 tmp = tmp << 8 | get_byte(pb); \ 368 } 369 370/** 371 * \brief resync the stream on the next media packet with specified properties 372 * \param max_interval how many bytes to search for matching packet at most 373 * \param track track id the media packet must belong to, -1 for any 374 * \param timestamp minimum timestamp (== field number) the packet must have, -1 for any 375 * \return timestamp of packet found 376 */ 377static int64_t gxf_resync_media(AVFormatContext *s, uint64_t max_interval, int track, int timestamp) { 378 uint32_t tmp; 379 uint64_t last_pos; 380 uint64_t last_found_pos = 0; 381 int cur_track; 382 int64_t cur_timestamp = AV_NOPTS_VALUE; 383 int len; 384 ByteIOContext *pb = s->pb; 385 GXFPktType type; 386 tmp = get_be32(pb); 387start: 388 while (tmp) 389 READ_ONE(); 390 READ_ONE(); 391 if (tmp != 1) 392 goto start; 393 last_pos = url_ftell(pb); 394 url_fseek(pb, -5, SEEK_CUR); 395 if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) { 396 url_fseek(pb, last_pos, SEEK_SET); 397 goto start; 398 } 399 get_byte(pb); 400 cur_track = get_byte(pb); 401 cur_timestamp = get_be32(pb); 402 last_found_pos = url_ftell(pb) - 16 - 6; 403 if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) { 404 url_fseek(pb, last_pos, SEEK_SET); 405 goto start; 406 } 407out: 408 if (last_found_pos) 409 url_fseek(pb, last_found_pos, SEEK_SET); 410 return cur_timestamp; 411} 412 413static int gxf_packet(AVFormatContext *s, AVPacket *pkt) { 414 ByteIOContext *pb = s->pb; 415 GXFPktType pkt_type; 416 int pkt_len; 417 while (!url_feof(pb)) { 418 AVStream *st; 419 int track_type, track_id, ret; 420 int field_nr, field_info, skip = 0; 421 int stream_index; 422 if (!parse_packet_header(pb, &pkt_type, &pkt_len)) { 423 if (!url_feof(pb)) 424 av_log(s, AV_LOG_ERROR, "sync lost\n"); 425 return -1; 426 } 427 if (pkt_type == PKT_FLT) { 428 gxf_read_index(s, pkt_len); 429 continue; 430 } 431 if (pkt_type != PKT_MEDIA) { 432 url_fskip(pb, pkt_len); 433 continue; 434 } 435 if (pkt_len < 16) { 436 av_log(s, AV_LOG_ERROR, "invalid media packet length\n"); 437 continue; 438 } 439 pkt_len -= 16; 440 track_type = get_byte(pb); 441 track_id = get_byte(pb); 442 stream_index = get_sindex(s, track_id, track_type); 443 if (stream_index < 0) 444 return stream_index; 445 st = s->streams[stream_index]; 446 field_nr = get_be32(pb); 447 field_info = get_be32(pb); 448 get_be32(pb); // "timeline" field number 449 get_byte(pb); // flags 450 get_byte(pb); // reserved 451 if (st->codec->codec_id == CODEC_ID_PCM_S24LE || 452 st->codec->codec_id == CODEC_ID_PCM_S16LE) { 453 int first = field_info >> 16; 454 int last = field_info & 0xffff; // last is exclusive 455 int bps = av_get_bits_per_sample(st->codec->codec_id)>>3; 456 if (first <= last && last*bps <= pkt_len) { 457 url_fskip(pb, first*bps); 458 skip = pkt_len - last*bps; 459 pkt_len = (last-first)*bps; 460 } else 461 av_log(s, AV_LOG_ERROR, "invalid first and last sample values\n"); 462 } 463 ret = av_get_packet(pb, pkt, pkt_len); 464 if (skip) 465 url_fskip(pb, skip); 466 pkt->stream_index = stream_index; 467 pkt->dts = field_nr; 468 return ret; 469 } 470 return AVERROR(EIO); 471} 472 473static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) { 474 uint64_t pos; 475 uint64_t maxlen = 100 * 1024 * 1024; 476 AVStream *st = s->streams[0]; 477 int64_t start_time = s->streams[stream_index]->start_time; 478 int64_t found; 479 int idx; 480 if (timestamp < start_time) timestamp = start_time; 481 idx = av_index_search_timestamp(st, timestamp - start_time, 482 AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD); 483 if (idx < 0) 484 return -1; 485 pos = st->index_entries[idx].pos; 486 if (idx < st->nb_index_entries - 2) 487 maxlen = st->index_entries[idx + 2].pos - pos; 488 maxlen = FFMAX(maxlen, 200 * 1024); 489 url_fseek(s->pb, pos, SEEK_SET); 490 found = gxf_resync_media(s, maxlen, -1, timestamp); 491 if (FFABS(found - timestamp) > 4) 492 return -1; 493 return 0; 494} 495 496static int64_t gxf_read_timestamp(AVFormatContext *s, int stream_index, 497 int64_t *pos, int64_t pos_limit) { 498 ByteIOContext *pb = s->pb; 499 int64_t res; 500 url_fseek(pb, *pos, SEEK_SET); 501 res = gxf_resync_media(s, pos_limit - *pos, -1, -1); 502 *pos = url_ftell(pb); 503 return res; 504} 505 506AVInputFormat gxf_demuxer = { 507 "gxf", 508 NULL_IF_CONFIG_SMALL("GXF format"), 509 0, 510 gxf_probe, 511 gxf_header, 512 gxf_packet, 513 NULL, 514 gxf_seek, 515 gxf_read_timestamp, 516}; 517