Libav
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00001 /* 00002 * GXF demuxer. 00003 * Copyright (c) 2006 Reimar Doeffinger 00004 * 00005 * This file is part of FFmpeg. 00006 * 00007 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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 "gxf.h" 00025 00026 struct gxf_stream_info { 00027 int64_t first_field; 00028 int64_t last_field; 00029 AVRational frames_per_second; 00030 int32_t fields_per_frame; 00031 }; 00032 00040 static int parse_packet_header(ByteIOContext *pb, GXFPktType *type, int *length) { 00041 if (get_be32(pb)) 00042 return 0; 00043 if (get_byte(pb) != 1) 00044 return 0; 00045 *type = get_byte(pb); 00046 *length = get_be32(pb); 00047 if ((*length >> 24) || *length < 16) 00048 return 0; 00049 *length -= 16; 00050 if (get_be32(pb)) 00051 return 0; 00052 if (get_byte(pb) != 0xe1) 00053 return 0; 00054 if (get_byte(pb) != 0xe2) 00055 return 0; 00056 return 1; 00057 } 00058 00062 static int gxf_probe(AVProbeData *p) { 00063 static const uint8_t startcode[] = {0, 0, 0, 0, 1, 0xbc}; // start with map packet 00064 static const uint8_t endcode[] = {0, 0, 0, 0, 0xe1, 0xe2}; 00065 if (!memcmp(p->buf, startcode, sizeof(startcode)) && 00066 !memcmp(&p->buf[16 - sizeof(endcode)], endcode, sizeof(endcode))) 00067 return AVPROBE_SCORE_MAX; 00068 return 0; 00069 } 00070 00077 static int get_sindex(AVFormatContext *s, int id, int format) { 00078 int i; 00079 AVStream *st = NULL; 00080 for (i = 0; i < s->nb_streams; i++) { 00081 if (s->streams[i]->id == id) 00082 return i; 00083 } 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(ByteIOContext *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 = get_byte(pb); 00165 int tlen = get_byte(pb); 00166 *len -= 2; 00167 if (tlen > *len) 00168 return; 00169 *len -= tlen; 00170 if (tlen == 4) { 00171 uint32_t value = get_be32(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 url_fskip(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(ByteIOContext *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 = get_byte(pb); 00214 int tlen = get_byte(pb); 00215 *len -= 2; 00216 if (tlen > *len) 00217 return; 00218 *len -= tlen; 00219 if (tlen == 4) { 00220 uint32_t value = get_be32(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 url_fskip(pb, tlen); 00227 } 00228 } 00229 00233 static void gxf_read_index(AVFormatContext *s, int pkt_len) { 00234 ByteIOContext *pb = s->pb; 00235 AVStream *st = s->streams[0]; 00236 uint32_t fields_per_map = get_le32(pb); 00237 uint32_t map_cnt = get_le32(pb); 00238 int i; 00239 pkt_len -= 8; 00240 if (map_cnt > 1000) { 00241 av_log(s, AV_LOG_ERROR, "too many index entries %u (%x)\n", map_cnt, map_cnt); 00242 map_cnt = 1000; 00243 } 00244 if (pkt_len < 4 * map_cnt) { 00245 av_log(s, AV_LOG_ERROR, "invalid index length\n"); 00246 url_fskip(pb, pkt_len); 00247 return; 00248 } 00249 pkt_len -= 4 * map_cnt; 00250 av_add_index_entry(st, 0, 0, 0, 0, 0); 00251 for (i = 0; i < map_cnt; i++) 00252 av_add_index_entry(st, (uint64_t)get_le32(pb) * 1024, 00253 i * (uint64_t)fields_per_map + 1, 0, 0, 0); 00254 url_fskip(pb, pkt_len); 00255 } 00256 00257 static int gxf_header(AVFormatContext *s, AVFormatParameters *ap) { 00258 ByteIOContext *pb = s->pb; 00259 GXFPktType pkt_type; 00260 int map_len; 00261 int len; 00262 AVRational main_timebase = {0, 0}; 00263 struct gxf_stream_info si; 00264 int i; 00265 if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) { 00266 av_log(s, AV_LOG_ERROR, "map packet not found\n"); 00267 return 0; 00268 } 00269 map_len -= 2; 00270 if (get_byte(pb) != 0x0e0 || get_byte(pb) != 0xff) { 00271 av_log(s, AV_LOG_ERROR, "unknown version or invalid map preamble\n"); 00272 return 0; 00273 } 00274 map_len -= 2; 00275 len = get_be16(pb); // length of material data section 00276 if (len > map_len) { 00277 av_log(s, AV_LOG_ERROR, "material data longer than map data\n"); 00278 return 0; 00279 } 00280 map_len -= len; 00281 gxf_material_tags(pb, &len, &si); 00282 url_fskip(pb, len); 00283 map_len -= 2; 00284 len = get_be16(pb); // length of track description 00285 if (len > map_len) { 00286 av_log(s, AV_LOG_ERROR, "track description longer than map data\n"); 00287 return 0; 00288 } 00289 map_len -= len; 00290 while (len > 0) { 00291 int track_type, track_id, track_len; 00292 AVStream *st; 00293 int idx; 00294 len -= 4; 00295 track_type = get_byte(pb); 00296 track_id = get_byte(pb); 00297 track_len = get_be16(pb); 00298 len -= track_len; 00299 gxf_track_tags(pb, &track_len, &si); 00300 url_fskip(pb, track_len); 00301 if (!(track_type & 0x80)) { 00302 av_log(s, AV_LOG_ERROR, "invalid track type %x\n", track_type); 00303 continue; 00304 } 00305 track_type &= 0x7f; 00306 if ((track_id & 0xc0) != 0xc0) { 00307 av_log(s, AV_LOG_ERROR, "invalid track id %x\n", track_id); 00308 continue; 00309 } 00310 track_id &= 0x3f; 00311 idx = get_sindex(s, track_id, track_type); 00312 if (idx < 0) continue; 00313 st = s->streams[idx]; 00314 if (!main_timebase.num || !main_timebase.den) { 00315 main_timebase.num = si.frames_per_second.den; 00316 main_timebase.den = si.frames_per_second.num * 2; 00317 } 00318 st->start_time = si.first_field; 00319 if (si.first_field != AV_NOPTS_VALUE && si.last_field != AV_NOPTS_VALUE) 00320 st->duration = si.last_field - si.first_field; 00321 } 00322 if (len < 0) 00323 av_log(s, AV_LOG_ERROR, "invalid track description length specified\n"); 00324 if (map_len) 00325 url_fskip(pb, map_len); 00326 if (!parse_packet_header(pb, &pkt_type, &len)) { 00327 av_log(s, AV_LOG_ERROR, "sync lost in header\n"); 00328 return -1; 00329 } 00330 if (pkt_type == PKT_FLT) { 00331 gxf_read_index(s, len); 00332 if (!parse_packet_header(pb, &pkt_type, &len)) { 00333 av_log(s, AV_LOG_ERROR, "sync lost in header\n"); 00334 return -1; 00335 } 00336 } 00337 if (pkt_type == PKT_UMF) { 00338 if (len >= 0x39) { 00339 AVRational fps; 00340 len -= 0x39; 00341 url_fskip(pb, 5); // preamble 00342 url_fskip(pb, 0x30); // payload description 00343 fps = fps_umf2avr(get_le32(pb)); 00344 if (!main_timebase.num || !main_timebase.den) { 00345 // this may not always be correct, but simply the best we can get 00346 main_timebase.num = fps.den; 00347 main_timebase.den = fps.num * 2; 00348 } 00349 } else 00350 av_log(s, AV_LOG_INFO, "UMF packet too short\n"); 00351 } else 00352 av_log(s, AV_LOG_INFO, "UMF packet missing\n"); 00353 url_fskip(pb, len); 00354 // set a fallback value, 60000/1001 is specified for audio-only files 00355 // so use that regardless of why we do not know the video frame rate. 00356 if (!main_timebase.num || !main_timebase.den) 00357 main_timebase = (AVRational){1001, 60000}; 00358 for (i = 0; i < s->nb_streams; i++) { 00359 AVStream *st = s->streams[i]; 00360 av_set_pts_info(st, 32, main_timebase.num, main_timebase.den); 00361 } 00362 return 0; 00363 } 00364 00365 #define READ_ONE() \ 00366 { \ 00367 if (!max_interval-- || url_feof(pb)) \ 00368 goto out; \ 00369 tmp = tmp << 8 | get_byte(pb); \ 00370 } 00371 00379 static int64_t gxf_resync_media(AVFormatContext *s, uint64_t max_interval, int track, int timestamp) { 00380 uint32_t tmp; 00381 uint64_t last_pos; 00382 uint64_t last_found_pos = 0; 00383 int cur_track; 00384 int64_t cur_timestamp = AV_NOPTS_VALUE; 00385 int len; 00386 ByteIOContext *pb = s->pb; 00387 GXFPktType type; 00388 tmp = get_be32(pb); 00389 start: 00390 while (tmp) 00391 READ_ONE(); 00392 READ_ONE(); 00393 if (tmp != 1) 00394 goto start; 00395 last_pos = url_ftell(pb); 00396 url_fseek(pb, -5, SEEK_CUR); 00397 if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) { 00398 url_fseek(pb, last_pos, SEEK_SET); 00399 goto start; 00400 } 00401 get_byte(pb); 00402 cur_track = get_byte(pb); 00403 cur_timestamp = get_be32(pb); 00404 last_found_pos = url_ftell(pb) - 16 - 6; 00405 if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) { 00406 url_fseek(pb, last_pos, SEEK_SET); 00407 goto start; 00408 } 00409 out: 00410 if (last_found_pos) 00411 url_fseek(pb, last_found_pos, SEEK_SET); 00412 return cur_timestamp; 00413 } 00414 00415 static int gxf_packet(AVFormatContext *s, AVPacket *pkt) { 00416 ByteIOContext *pb = s->pb; 00417 GXFPktType pkt_type; 00418 int pkt_len; 00419 while (!url_feof(pb)) { 00420 AVStream *st; 00421 int track_type, track_id, ret; 00422 int field_nr, field_info, skip = 0; 00423 int stream_index; 00424 if (!parse_packet_header(pb, &pkt_type, &pkt_len)) { 00425 if (!url_feof(pb)) 00426 av_log(s, AV_LOG_ERROR, "sync lost\n"); 00427 return -1; 00428 } 00429 if (pkt_type == PKT_FLT) { 00430 gxf_read_index(s, pkt_len); 00431 continue; 00432 } 00433 if (pkt_type != PKT_MEDIA) { 00434 url_fskip(pb, pkt_len); 00435 continue; 00436 } 00437 if (pkt_len < 16) { 00438 av_log(s, AV_LOG_ERROR, "invalid media packet length\n"); 00439 continue; 00440 } 00441 pkt_len -= 16; 00442 track_type = get_byte(pb); 00443 track_id = get_byte(pb); 00444 stream_index = get_sindex(s, track_id, track_type); 00445 if (stream_index < 0) 00446 return stream_index; 00447 st = s->streams[stream_index]; 00448 field_nr = get_be32(pb); 00449 field_info = get_be32(pb); 00450 get_be32(pb); // "timeline" field number 00451 get_byte(pb); // flags 00452 get_byte(pb); // reserved 00453 if (st->codec->codec_id == CODEC_ID_PCM_S24LE || 00454 st->codec->codec_id == CODEC_ID_PCM_S16LE) { 00455 int first = field_info >> 16; 00456 int last = field_info & 0xffff; // last is exclusive 00457 int bps = av_get_bits_per_sample(st->codec->codec_id)>>3; 00458 if (first <= last && last*bps <= pkt_len) { 00459 url_fskip(pb, first*bps); 00460 skip = pkt_len - last*bps; 00461 pkt_len = (last-first)*bps; 00462 } else 00463 av_log(s, AV_LOG_ERROR, "invalid first and last sample values\n"); 00464 } 00465 ret = av_get_packet(pb, pkt, pkt_len); 00466 if (skip) 00467 url_fskip(pb, skip); 00468 pkt->stream_index = stream_index; 00469 pkt->dts = field_nr; 00470 return ret; 00471 } 00472 return AVERROR(EIO); 00473 } 00474 00475 static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) { 00476 uint64_t pos; 00477 uint64_t maxlen = 100 * 1024 * 1024; 00478 AVStream *st = s->streams[0]; 00479 int64_t start_time = s->streams[stream_index]->start_time; 00480 int64_t found; 00481 int idx; 00482 if (timestamp < start_time) timestamp = start_time; 00483 idx = av_index_search_timestamp(st, timestamp - start_time, 00484 AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD); 00485 if (idx < 0) 00486 return -1; 00487 pos = st->index_entries[idx].pos; 00488 if (idx < st->nb_index_entries - 2) 00489 maxlen = st->index_entries[idx + 2].pos - pos; 00490 maxlen = FFMAX(maxlen, 200 * 1024); 00491 url_fseek(s->pb, pos, SEEK_SET); 00492 found = gxf_resync_media(s, maxlen, -1, timestamp); 00493 if (FFABS(found - timestamp) > 4) 00494 return -1; 00495 return 0; 00496 } 00497 00498 static int64_t gxf_read_timestamp(AVFormatContext *s, int stream_index, 00499 int64_t *pos, int64_t pos_limit) { 00500 ByteIOContext *pb = s->pb; 00501 int64_t res; 00502 url_fseek(pb, *pos, SEEK_SET); 00503 res = gxf_resync_media(s, pos_limit - *pos, -1, -1); 00504 *pos = url_ftell(pb); 00505 return res; 00506 } 00507 00508 AVInputFormat gxf_demuxer = { 00509 "gxf", 00510 NULL_IF_CONFIG_SMALL("GXF format"), 00511 0, 00512 gxf_probe, 00513 gxf_header, 00514 gxf_packet, 00515 NULL, 00516 gxf_seek, 00517 gxf_read_timestamp, 00518 };