Libav 0.7.1
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00001 /* 00002 * GXF demuxer. 00003 * Copyright (c) 2006 Reimar Doeffinger 00004 * 00005 * This file is part of Libav. 00006 * 00007 * Libav is free software; you can redistribute it and/or 00008 * modify it under the terms of the GNU Lesser General Public 00009 * License as published by the Free Software Foundation; either 00010 * version 2.1 of the License, or (at your option) any later version. 00011 * 00012 * Libav is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00015 * Lesser General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU Lesser General Public 00018 * License along with Libav; if not, write to the Free Software 00019 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00020 */ 00021 00022 #include "libavutil/common.h" 00023 #include "avformat.h" 00024 #include "internal.h" 00025 #include "gxf.h" 00026 00027 struct gxf_stream_info { 00028 int64_t first_field; 00029 int64_t last_field; 00030 AVRational frames_per_second; 00031 int32_t fields_per_frame; 00032 }; 00033 00041 static int parse_packet_header(AVIOContext *pb, GXFPktType *type, int *length) { 00042 if (avio_rb32(pb)) 00043 return 0; 00044 if (avio_r8(pb) != 1) 00045 return 0; 00046 *type = avio_r8(pb); 00047 *length = avio_rb32(pb); 00048 if ((*length >> 24) || *length < 16) 00049 return 0; 00050 *length -= 16; 00051 if (avio_rb32(pb)) 00052 return 0; 00053 if (avio_r8(pb) != 0xe1) 00054 return 0; 00055 if (avio_r8(pb) != 0xe2) 00056 return 0; 00057 return 1; 00058 } 00059 00063 static int gxf_probe(AVProbeData *p) { 00064 static const uint8_t startcode[] = {0, 0, 0, 0, 1, 0xbc}; // start with map packet 00065 static const uint8_t endcode[] = {0, 0, 0, 0, 0xe1, 0xe2}; 00066 if (!memcmp(p->buf, startcode, sizeof(startcode)) && 00067 !memcmp(&p->buf[16 - sizeof(endcode)], endcode, sizeof(endcode))) 00068 return AVPROBE_SCORE_MAX; 00069 return 0; 00070 } 00071 00078 static int get_sindex(AVFormatContext *s, int id, int format) { 00079 int i; 00080 AVStream *st = NULL; 00081 i = ff_find_stream_index(s, id); 00082 if (i >= 0) 00083 return i; 00084 st = av_new_stream(s, id); 00085 if (!st) 00086 return AVERROR(ENOMEM); 00087 switch (format) { 00088 case 3: 00089 case 4: 00090 st->codec->codec_type = AVMEDIA_TYPE_VIDEO; 00091 st->codec->codec_id = CODEC_ID_MJPEG; 00092 break; 00093 case 13: 00094 case 15: 00095 st->codec->codec_type = AVMEDIA_TYPE_VIDEO; 00096 st->codec->codec_id = CODEC_ID_DVVIDEO; 00097 break; 00098 case 14: 00099 case 16: 00100 st->codec->codec_type = AVMEDIA_TYPE_VIDEO; 00101 st->codec->codec_id = CODEC_ID_DVVIDEO; 00102 break; 00103 case 11: 00104 case 12: 00105 case 20: 00106 st->codec->codec_type = AVMEDIA_TYPE_VIDEO; 00107 st->codec->codec_id = CODEC_ID_MPEG2VIDEO; 00108 st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc. 00109 break; 00110 case 22: 00111 case 23: 00112 st->codec->codec_type = AVMEDIA_TYPE_VIDEO; 00113 st->codec->codec_id = CODEC_ID_MPEG1VIDEO; 00114 st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc. 00115 break; 00116 case 9: 00117 st->codec->codec_type = AVMEDIA_TYPE_AUDIO; 00118 st->codec->codec_id = CODEC_ID_PCM_S24LE; 00119 st->codec->channels = 1; 00120 st->codec->sample_rate = 48000; 00121 st->codec->bit_rate = 3 * 1 * 48000 * 8; 00122 st->codec->block_align = 3 * 1; 00123 st->codec->bits_per_coded_sample = 24; 00124 break; 00125 case 10: 00126 st->codec->codec_type = AVMEDIA_TYPE_AUDIO; 00127 st->codec->codec_id = CODEC_ID_PCM_S16LE; 00128 st->codec->channels = 1; 00129 st->codec->sample_rate = 48000; 00130 st->codec->bit_rate = 2 * 1 * 48000 * 8; 00131 st->codec->block_align = 2 * 1; 00132 st->codec->bits_per_coded_sample = 16; 00133 break; 00134 case 17: 00135 st->codec->codec_type = AVMEDIA_TYPE_AUDIO; 00136 st->codec->codec_id = CODEC_ID_AC3; 00137 st->codec->channels = 2; 00138 st->codec->sample_rate = 48000; 00139 break; 00140 // timecode tracks: 00141 case 7: 00142 case 8: 00143 case 24: 00144 st->codec->codec_type = AVMEDIA_TYPE_DATA; 00145 st->codec->codec_id = CODEC_ID_NONE; 00146 break; 00147 default: 00148 st->codec->codec_type = AVMEDIA_TYPE_UNKNOWN; 00149 st->codec->codec_id = CODEC_ID_NONE; 00150 break; 00151 } 00152 return s->nb_streams - 1; 00153 } 00154 00160 static void gxf_material_tags(AVIOContext *pb, int *len, struct gxf_stream_info *si) { 00161 si->first_field = AV_NOPTS_VALUE; 00162 si->last_field = AV_NOPTS_VALUE; 00163 while (*len >= 2) { 00164 GXFMatTag tag = avio_r8(pb); 00165 int tlen = avio_r8(pb); 00166 *len -= 2; 00167 if (tlen > *len) 00168 return; 00169 *len -= tlen; 00170 if (tlen == 4) { 00171 uint32_t value = avio_rb32(pb); 00172 if (tag == MAT_FIRST_FIELD) 00173 si->first_field = value; 00174 else if (tag == MAT_LAST_FIELD) 00175 si->last_field = value; 00176 } else 00177 avio_skip(pb, tlen); 00178 } 00179 } 00180 00186 static AVRational fps_tag2avr(int32_t fps) { 00187 extern const AVRational ff_frame_rate_tab[]; 00188 if (fps < 1 || fps > 9) fps = 9; 00189 return ff_frame_rate_tab[9 - fps]; // values have opposite order 00190 } 00191 00197 static AVRational fps_umf2avr(uint32_t flags) { 00198 static const AVRational map[] = {{50, 1}, {60000, 1001}, {24, 1}, 00199 {25, 1}, {30000, 1001}}; 00200 int idx = av_log2((flags & 0x7c0) >> 6); 00201 return map[idx]; 00202 } 00203 00209 static void gxf_track_tags(AVIOContext *pb, int *len, struct gxf_stream_info *si) { 00210 si->frames_per_second = (AVRational){0, 0}; 00211 si->fields_per_frame = 0; 00212 while (*len >= 2) { 00213 GXFTrackTag tag = avio_r8(pb); 00214 int tlen = avio_r8(pb); 00215 *len -= 2; 00216 if (tlen > *len) 00217 return; 00218 *len -= tlen; 00219 if (tlen == 4) { 00220 uint32_t value = avio_rb32(pb); 00221 if (tag == TRACK_FPS) 00222 si->frames_per_second = fps_tag2avr(value); 00223 else if (tag == TRACK_FPF && (value == 1 || value == 2)) 00224 si->fields_per_frame = value; 00225 } else 00226 avio_skip(pb, tlen); 00227 } 00228 } 00229 00233 static void gxf_read_index(AVFormatContext *s, int pkt_len) { 00234 AVIOContext *pb = s->pb; 00235 AVStream *st = s->streams[0]; 00236 uint32_t fields_per_map = avio_rl32(pb); 00237 uint32_t map_cnt = avio_rl32(pb); 00238 int i; 00239 pkt_len -= 8; 00240 if (s->flags & AVFMT_FLAG_IGNIDX) { 00241 avio_skip(pb, pkt_len); 00242 return; 00243 } 00244 if (map_cnt > 1000) { 00245 av_log(s, AV_LOG_ERROR, "too many index entries %u (%x)\n", map_cnt, map_cnt); 00246 map_cnt = 1000; 00247 } 00248 if (pkt_len < 4 * map_cnt) { 00249 av_log(s, AV_LOG_ERROR, "invalid index length\n"); 00250 avio_skip(pb, pkt_len); 00251 return; 00252 } 00253 pkt_len -= 4 * map_cnt; 00254 av_add_index_entry(st, 0, 0, 0, 0, 0); 00255 for (i = 0; i < map_cnt; i++) 00256 av_add_index_entry(st, (uint64_t)avio_rl32(pb) * 1024, 00257 i * (uint64_t)fields_per_map + 1, 0, 0, 0); 00258 avio_skip(pb, pkt_len); 00259 } 00260 00261 static int gxf_header(AVFormatContext *s, AVFormatParameters *ap) { 00262 AVIOContext *pb = s->pb; 00263 GXFPktType pkt_type; 00264 int map_len; 00265 int len; 00266 AVRational main_timebase = {0, 0}; 00267 struct gxf_stream_info *si = s->priv_data; 00268 int i; 00269 if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) { 00270 av_log(s, AV_LOG_ERROR, "map packet not found\n"); 00271 return 0; 00272 } 00273 map_len -= 2; 00274 if (avio_r8(pb) != 0x0e0 || avio_r8(pb) != 0xff) { 00275 av_log(s, AV_LOG_ERROR, "unknown version or invalid map preamble\n"); 00276 return 0; 00277 } 00278 map_len -= 2; 00279 len = avio_rb16(pb); // length of material data section 00280 if (len > map_len) { 00281 av_log(s, AV_LOG_ERROR, "material data longer than map data\n"); 00282 return 0; 00283 } 00284 map_len -= len; 00285 gxf_material_tags(pb, &len, si); 00286 avio_skip(pb, len); 00287 map_len -= 2; 00288 len = avio_rb16(pb); // length of track description 00289 if (len > map_len) { 00290 av_log(s, AV_LOG_ERROR, "track description longer than map data\n"); 00291 return 0; 00292 } 00293 map_len -= len; 00294 while (len > 0) { 00295 int track_type, track_id, track_len; 00296 AVStream *st; 00297 int idx; 00298 len -= 4; 00299 track_type = avio_r8(pb); 00300 track_id = avio_r8(pb); 00301 track_len = avio_rb16(pb); 00302 len -= track_len; 00303 gxf_track_tags(pb, &track_len, si); 00304 avio_skip(pb, track_len); 00305 if (!(track_type & 0x80)) { 00306 av_log(s, AV_LOG_ERROR, "invalid track type %x\n", track_type); 00307 continue; 00308 } 00309 track_type &= 0x7f; 00310 if ((track_id & 0xc0) != 0xc0) { 00311 av_log(s, AV_LOG_ERROR, "invalid track id %x\n", track_id); 00312 continue; 00313 } 00314 track_id &= 0x3f; 00315 idx = get_sindex(s, track_id, track_type); 00316 if (idx < 0) continue; 00317 st = s->streams[idx]; 00318 if (!main_timebase.num || !main_timebase.den) { 00319 main_timebase.num = si->frames_per_second.den; 00320 main_timebase.den = si->frames_per_second.num * 2; 00321 } 00322 st->start_time = si->first_field; 00323 if (si->first_field != AV_NOPTS_VALUE && si->last_field != AV_NOPTS_VALUE) 00324 st->duration = si->last_field - si->first_field; 00325 } 00326 if (len < 0) 00327 av_log(s, AV_LOG_ERROR, "invalid track description length specified\n"); 00328 if (map_len) 00329 avio_skip(pb, map_len); 00330 if (!parse_packet_header(pb, &pkt_type, &len)) { 00331 av_log(s, AV_LOG_ERROR, "sync lost in header\n"); 00332 return -1; 00333 } 00334 if (pkt_type == PKT_FLT) { 00335 gxf_read_index(s, len); 00336 if (!parse_packet_header(pb, &pkt_type, &len)) { 00337 av_log(s, AV_LOG_ERROR, "sync lost in header\n"); 00338 return -1; 00339 } 00340 } 00341 if (pkt_type == PKT_UMF) { 00342 if (len >= 0x39) { 00343 AVRational fps; 00344 len -= 0x39; 00345 avio_skip(pb, 5); // preamble 00346 avio_skip(pb, 0x30); // payload description 00347 fps = fps_umf2avr(avio_rl32(pb)); 00348 if (!main_timebase.num || !main_timebase.den) { 00349 // this may not always be correct, but simply the best we can get 00350 main_timebase.num = fps.den; 00351 main_timebase.den = fps.num * 2; 00352 } 00353 } else 00354 av_log(s, AV_LOG_INFO, "UMF packet too short\n"); 00355 } else 00356 av_log(s, AV_LOG_INFO, "UMF packet missing\n"); 00357 avio_skip(pb, len); 00358 // set a fallback value, 60000/1001 is specified for audio-only files 00359 // so use that regardless of why we do not know the video frame rate. 00360 if (!main_timebase.num || !main_timebase.den) 00361 main_timebase = (AVRational){1001, 60000}; 00362 for (i = 0; i < s->nb_streams; i++) { 00363 AVStream *st = s->streams[i]; 00364 av_set_pts_info(st, 32, main_timebase.num, main_timebase.den); 00365 } 00366 return 0; 00367 } 00368 00369 #define READ_ONE() \ 00370 { \ 00371 if (!max_interval-- || pb->eof_reached) \ 00372 goto out; \ 00373 tmp = tmp << 8 | avio_r8(pb); \ 00374 } 00375 00383 static int64_t gxf_resync_media(AVFormatContext *s, uint64_t max_interval, int track, int timestamp) { 00384 uint32_t tmp; 00385 uint64_t last_pos; 00386 uint64_t last_found_pos = 0; 00387 int cur_track; 00388 int64_t cur_timestamp = AV_NOPTS_VALUE; 00389 int len; 00390 AVIOContext *pb = s->pb; 00391 GXFPktType type; 00392 tmp = avio_rb32(pb); 00393 start: 00394 while (tmp) 00395 READ_ONE(); 00396 READ_ONE(); 00397 if (tmp != 1) 00398 goto start; 00399 last_pos = avio_tell(pb); 00400 if (avio_seek(pb, -5, SEEK_CUR) < 0) 00401 goto out; 00402 if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) { 00403 if (avio_seek(pb, last_pos, SEEK_SET) < 0) 00404 goto out; 00405 goto start; 00406 } 00407 avio_r8(pb); 00408 cur_track = avio_r8(pb); 00409 cur_timestamp = avio_rb32(pb); 00410 last_found_pos = avio_tell(pb) - 16 - 6; 00411 if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) { 00412 if (avio_seek(pb, last_pos, SEEK_SET) >= 0) 00413 goto start; 00414 } 00415 out: 00416 if (last_found_pos) 00417 avio_seek(pb, last_found_pos, SEEK_SET); 00418 return cur_timestamp; 00419 } 00420 00421 static int gxf_packet(AVFormatContext *s, AVPacket *pkt) { 00422 AVIOContext *pb = s->pb; 00423 GXFPktType pkt_type; 00424 int pkt_len; 00425 struct gxf_stream_info *si = s->priv_data; 00426 00427 while (!pb->eof_reached) { 00428 AVStream *st; 00429 int track_type, track_id, ret; 00430 int field_nr, field_info, skip = 0; 00431 int stream_index; 00432 if (!parse_packet_header(pb, &pkt_type, &pkt_len)) { 00433 if (!pb->eof_reached) 00434 av_log(s, AV_LOG_ERROR, "sync lost\n"); 00435 return -1; 00436 } 00437 if (pkt_type == PKT_FLT) { 00438 gxf_read_index(s, pkt_len); 00439 continue; 00440 } 00441 if (pkt_type != PKT_MEDIA) { 00442 avio_skip(pb, pkt_len); 00443 continue; 00444 } 00445 if (pkt_len < 16) { 00446 av_log(s, AV_LOG_ERROR, "invalid media packet length\n"); 00447 continue; 00448 } 00449 pkt_len -= 16; 00450 track_type = avio_r8(pb); 00451 track_id = avio_r8(pb); 00452 stream_index = get_sindex(s, track_id, track_type); 00453 if (stream_index < 0) 00454 return stream_index; 00455 st = s->streams[stream_index]; 00456 field_nr = avio_rb32(pb); 00457 field_info = avio_rb32(pb); 00458 avio_rb32(pb); // "timeline" field number 00459 avio_r8(pb); // flags 00460 avio_r8(pb); // reserved 00461 if (st->codec->codec_id == CODEC_ID_PCM_S24LE || 00462 st->codec->codec_id == CODEC_ID_PCM_S16LE) { 00463 int first = field_info >> 16; 00464 int last = field_info & 0xffff; // last is exclusive 00465 int bps = av_get_bits_per_sample(st->codec->codec_id)>>3; 00466 if (first <= last && last*bps <= pkt_len) { 00467 avio_skip(pb, first*bps); 00468 skip = pkt_len - last*bps; 00469 pkt_len = (last-first)*bps; 00470 } else 00471 av_log(s, AV_LOG_ERROR, "invalid first and last sample values\n"); 00472 } 00473 ret = av_get_packet(pb, pkt, pkt_len); 00474 if (skip) 00475 avio_skip(pb, skip); 00476 pkt->stream_index = stream_index; 00477 pkt->dts = field_nr; 00478 00479 //set duration manually for DV or else lavf misdetects the frame rate 00480 if (st->codec->codec_id == CODEC_ID_DVVIDEO) 00481 pkt->duration = si->fields_per_frame; 00482 00483 return ret; 00484 } 00485 return AVERROR(EIO); 00486 } 00487 00488 static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) { 00489 int res = 0; 00490 uint64_t pos; 00491 uint64_t maxlen = 100 * 1024 * 1024; 00492 AVStream *st = s->streams[0]; 00493 int64_t start_time = s->streams[stream_index]->start_time; 00494 int64_t found; 00495 int idx; 00496 if (timestamp < start_time) timestamp = start_time; 00497 idx = av_index_search_timestamp(st, timestamp - start_time, 00498 AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD); 00499 if (idx < 0) 00500 return -1; 00501 pos = st->index_entries[idx].pos; 00502 if (idx < st->nb_index_entries - 2) 00503 maxlen = st->index_entries[idx + 2].pos - pos; 00504 maxlen = FFMAX(maxlen, 200 * 1024); 00505 res = avio_seek(s->pb, pos, SEEK_SET); 00506 if (res < 0) 00507 return res; 00508 found = gxf_resync_media(s, maxlen, -1, timestamp); 00509 if (FFABS(found - timestamp) > 4) 00510 return -1; 00511 return 0; 00512 } 00513 00514 static int64_t gxf_read_timestamp(AVFormatContext *s, int stream_index, 00515 int64_t *pos, int64_t pos_limit) { 00516 AVIOContext *pb = s->pb; 00517 int64_t res; 00518 if (avio_seek(pb, *pos, SEEK_SET) < 0) 00519 return AV_NOPTS_VALUE; 00520 res = gxf_resync_media(s, pos_limit - *pos, -1, -1); 00521 *pos = avio_tell(pb); 00522 return res; 00523 } 00524 00525 AVInputFormat ff_gxf_demuxer = { 00526 "gxf", 00527 NULL_IF_CONFIG_SMALL("GXF format"), 00528 sizeof(struct gxf_stream_info), 00529 gxf_probe, 00530 gxf_header, 00531 gxf_packet, 00532 NULL, 00533 gxf_seek, 00534 gxf_read_timestamp, 00535 };