3 * Copyright (c) 2006 Reimar Doeffinger
5 * This file is part of FFmpeg.
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.
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.
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
22 #include "libavutil/common.h"
26 #include "libavcodec/mpeg12data.h"
28 struct gxf_stream_info {
31 AVRational frames_per_second;
32 int32_t fields_per_frame;
33 int64_t track_aux_data;
37 * @brief parse gxf timecode and add it to metadata
39 static int add_timecode_metadata(AVDictionary **pm, const char *key, uint32_t timecode, int fields_per_frame)
42 int field = timecode & 0xff;
43 int frame = fields_per_frame ? field / fields_per_frame : field;
44 int second = (timecode >> 8) & 0xff;
45 int minute = (timecode >> 16) & 0xff;
46 int hour = (timecode >> 24) & 0x1f;
47 int drop = (timecode >> 29) & 1;
48 // bit 30: color_frame, unused
49 // ignore invalid time code
52 snprintf(tmp, sizeof(tmp), "%02d:%02d:%02d%c%02d",
53 hour, minute, second, drop ? ';' : ':', frame);
54 return av_dict_set(pm, key, tmp, 0);
58 * @brief parses a packet header, extracting type and length
59 * @param pb AVIOContext to read header from
60 * @param type detected packet type is stored here
61 * @param length detected packet length, excluding header is stored here
62 * @return 0 if header not found or contains invalid data, 1 otherwise
64 static int parse_packet_header(AVIOContext *pb, GXFPktType *type, int *length) {
70 *length = avio_rb32(pb);
71 if ((*length >> 24) || *length < 16)
76 if (avio_r8(pb) != 0xe1)
78 if (avio_r8(pb) != 0xe2)
84 * @brief check if file starts with a PKT_MAP header
86 static int gxf_probe(AVProbeData *p) {
87 static const uint8_t startcode[] = {0, 0, 0, 0, 1, 0xbc}; // start with map packet
88 static const uint8_t endcode[] = {0, 0, 0, 0, 0xe1, 0xe2};
89 if (!memcmp(p->buf, startcode, sizeof(startcode)) &&
90 !memcmp(&p->buf[16 - sizeof(endcode)], endcode, sizeof(endcode)))
91 return AVPROBE_SCORE_MAX;
96 * @brief gets the stream index for the track with the specified id, creates new
98 * @param id id of stream to find / add
99 * @param format stream format identifier
101 static int get_sindex(AVFormatContext *s, int id, int format) {
104 i = ff_find_stream_index(s, id);
107 st = avformat_new_stream(s, NULL);
109 return AVERROR(ENOMEM);
114 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
115 st->codec->codec_id = AV_CODEC_ID_MJPEG;
119 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
120 st->codec->codec_id = AV_CODEC_ID_DVVIDEO;
124 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
125 st->codec->codec_id = AV_CODEC_ID_DVVIDEO;
130 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
131 st->codec->codec_id = AV_CODEC_ID_MPEG2VIDEO;
132 st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
136 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
137 st->codec->codec_id = AV_CODEC_ID_MPEG1VIDEO;
138 st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
141 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
142 st->codec->codec_id = AV_CODEC_ID_PCM_S24LE;
143 st->codec->channels = 1;
144 st->codec->sample_rate = 48000;
145 st->codec->bit_rate = 3 * 1 * 48000 * 8;
146 st->codec->block_align = 3 * 1;
147 st->codec->bits_per_coded_sample = 24;
150 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
151 st->codec->codec_id = AV_CODEC_ID_PCM_S16LE;
152 st->codec->channels = 1;
153 st->codec->sample_rate = 48000;
154 st->codec->bit_rate = 2 * 1 * 48000 * 8;
155 st->codec->block_align = 2 * 1;
156 st->codec->bits_per_coded_sample = 16;
159 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
160 st->codec->codec_id = AV_CODEC_ID_AC3;
161 st->codec->channels = 2;
162 st->codec->sample_rate = 48000;
168 st->codec->codec_type = AVMEDIA_TYPE_DATA;
169 st->codec->codec_id = AV_CODEC_ID_NONE;
172 st->codec->codec_type = AVMEDIA_TYPE_UNKNOWN;
173 st->codec->codec_id = AV_CODEC_ID_NONE;
176 return s->nb_streams - 1;
180 * @brief filters out interesting tags from material information.
181 * @param len length of tag section, will be adjusted to contain remaining bytes
182 * @param si struct to store collected information into
184 static void gxf_material_tags(AVIOContext *pb, int *len, struct gxf_stream_info *si) {
185 si->first_field = AV_NOPTS_VALUE;
186 si->last_field = AV_NOPTS_VALUE;
188 GXFMatTag tag = avio_r8(pb);
189 int tlen = avio_r8(pb);
195 uint32_t value = avio_rb32(pb);
196 if (tag == MAT_FIRST_FIELD)
197 si->first_field = value;
198 else if (tag == MAT_LAST_FIELD)
199 si->last_field = value;
205 static const AVRational frame_rate_tab[] = {
218 * @brief convert fps tag value to AVRational fps
219 * @param fps fps value from tag
220 * @return fps as AVRational, or 0 / 0 if unknown
222 static AVRational fps_tag2avr(int32_t fps) {
223 if (fps < 1 || fps > 9) fps = 9;
224 return frame_rate_tab[fps - 1];
228 * @brief convert UMF attributes flags to AVRational fps
229 * @param flags UMF flags to convert
230 * @return fps as AVRational, or 0 / 0 if unknown
232 static AVRational fps_umf2avr(uint32_t flags) {
233 static const AVRational map[] = {{50, 1}, {60000, 1001}, {24, 1},
234 {25, 1}, {30000, 1001}};
235 int idx = av_log2((flags & 0x7c0) >> 6);
240 * @brief filters out interesting tags from track information.
241 * @param len length of tag section, will be adjusted to contain remaining bytes
242 * @param si struct to store collected information into
244 static void gxf_track_tags(AVIOContext *pb, int *len, struct gxf_stream_info *si) {
245 si->frames_per_second = (AVRational){0, 0};
246 si->fields_per_frame = 0;
247 si->track_aux_data = 0x80000000;
249 GXFTrackTag tag = avio_r8(pb);
250 int tlen = avio_r8(pb);
256 uint32_t value = avio_rb32(pb);
257 if (tag == TRACK_FPS)
258 si->frames_per_second = fps_tag2avr(value);
259 else if (tag == TRACK_FPF && (value == 1 || value == 2))
260 si->fields_per_frame = value;
261 } else if (tlen == 8 && tag == TRACK_AUX)
262 si->track_aux_data = avio_rl64(pb);
269 * @brief read index from FLT packet into stream 0 av_index
271 static void gxf_read_index(AVFormatContext *s, int pkt_len) {
272 AVIOContext *pb = s->pb;
273 AVStream *st = s->streams[0];
274 uint32_t fields_per_map = avio_rl32(pb);
275 uint32_t map_cnt = avio_rl32(pb);
278 if (s->flags & AVFMT_FLAG_IGNIDX) {
279 avio_skip(pb, pkt_len);
282 if (map_cnt > 1000) {
283 av_log(s, AV_LOG_ERROR, "too many index entries %u (%x)\n", map_cnt, map_cnt);
286 if (pkt_len < 4 * map_cnt) {
287 av_log(s, AV_LOG_ERROR, "invalid index length\n");
288 avio_skip(pb, pkt_len);
291 pkt_len -= 4 * map_cnt;
292 av_add_index_entry(st, 0, 0, 0, 0, 0);
293 for (i = 0; i < map_cnt; i++)
294 av_add_index_entry(st, (uint64_t)avio_rl32(pb) * 1024,
295 i * (uint64_t)fields_per_map + 1, 0, 0, 0);
296 avio_skip(pb, pkt_len);
299 static int gxf_header(AVFormatContext *s) {
300 AVIOContext *pb = s->pb;
304 AVRational main_timebase = {0, 0};
305 struct gxf_stream_info *si = s->priv_data;
307 if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) {
308 av_log(s, AV_LOG_ERROR, "map packet not found\n");
312 if (avio_r8(pb) != 0x0e0 || avio_r8(pb) != 0xff) {
313 av_log(s, AV_LOG_ERROR, "unknown version or invalid map preamble\n");
317 len = avio_rb16(pb); // length of material data section
319 av_log(s, AV_LOG_ERROR, "material data longer than map data\n");
323 gxf_material_tags(pb, &len, si);
326 len = avio_rb16(pb); // length of track description
328 av_log(s, AV_LOG_ERROR, "track description longer than map data\n");
333 int track_type, track_id, track_len;
337 track_type = avio_r8(pb);
338 track_id = avio_r8(pb);
339 track_len = avio_rb16(pb);
341 if (!(track_type & 0x80)) {
342 av_log(s, AV_LOG_ERROR, "invalid track type %x\n", track_type);
346 if ((track_id & 0xc0) != 0xc0) {
347 av_log(s, AV_LOG_ERROR, "invalid track id %x\n", track_id);
351 gxf_track_tags(pb, &track_len, si);
352 // check for timecode tracks
353 if (track_type == 7 || track_type == 8 || track_type == 24) {
354 add_timecode_metadata(&s->metadata, "timecode",
355 si->track_aux_data & 0xffffffff,
356 si->fields_per_frame);
359 avio_skip(pb, track_len);
361 idx = get_sindex(s, track_id, track_type);
362 if (idx < 0) continue;
363 st = s->streams[idx];
364 if (!main_timebase.num || !main_timebase.den) {
365 main_timebase.num = si->frames_per_second.den;
366 main_timebase.den = si->frames_per_second.num * 2;
368 st->start_time = si->first_field;
369 if (si->first_field != AV_NOPTS_VALUE && si->last_field != AV_NOPTS_VALUE)
370 st->duration = si->last_field - si->first_field;
373 av_log(s, AV_LOG_ERROR, "invalid track description length specified\n");
375 avio_skip(pb, map_len);
376 if (!parse_packet_header(pb, &pkt_type, &len)) {
377 av_log(s, AV_LOG_ERROR, "sync lost in header\n");
380 if (pkt_type == PKT_FLT) {
381 gxf_read_index(s, len);
382 if (!parse_packet_header(pb, &pkt_type, &len)) {
383 av_log(s, AV_LOG_ERROR, "sync lost in header\n");
387 if (pkt_type == PKT_UMF) {
391 avio_skip(pb, 5); // preamble
392 avio_skip(pb, 0x30); // payload description
393 fps = fps_umf2avr(avio_rl32(pb));
394 if (!main_timebase.num || !main_timebase.den) {
395 av_log(s, AV_LOG_WARNING, "No FPS track tag, using UMF fps tag."
396 " This might give wrong results.\n");
397 // this may not always be correct, but simply the best we can get
398 main_timebase.num = fps.den;
399 main_timebase.den = fps.num * 2;
405 add_timecode_metadata(&s->metadata, "timecode_at_mark_in",
406 avio_rl32(pb), si->fields_per_frame);
407 add_timecode_metadata(&s->metadata, "timecode_at_mark_out",
408 avio_rl32(pb), si->fields_per_frame);
411 av_log(s, AV_LOG_INFO, "UMF packet too short\n");
413 av_log(s, AV_LOG_INFO, "UMF packet missing\n");
415 // set a fallback value, 60000/1001 is specified for audio-only files
416 // so use that regardless of why we do not know the video frame rate.
417 if (!main_timebase.num || !main_timebase.den)
418 main_timebase = (AVRational){1001, 60000};
419 for (i = 0; i < s->nb_streams; i++) {
420 AVStream *st = s->streams[i];
421 avpriv_set_pts_info(st, 32, main_timebase.num, main_timebase.den);
428 if (!max_interval-- || url_feof(pb)) \
430 tmp = tmp << 8 | avio_r8(pb); \
434 * @brief resync the stream on the next media packet with specified properties
435 * @param max_interval how many bytes to search for matching packet at most
436 * @param track track id the media packet must belong to, -1 for any
437 * @param timestamp minimum timestamp (== field number) the packet must have, -1 for any
438 * @return timestamp of packet found
440 static int64_t gxf_resync_media(AVFormatContext *s, uint64_t max_interval, int track, int timestamp) {
443 uint64_t last_found_pos = 0;
445 int64_t cur_timestamp = AV_NOPTS_VALUE;
447 AVIOContext *pb = s->pb;
456 last_pos = avio_tell(pb);
457 if (avio_seek(pb, -5, SEEK_CUR) < 0)
459 if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) {
460 if (avio_seek(pb, last_pos, SEEK_SET) < 0)
465 cur_track = avio_r8(pb);
466 cur_timestamp = avio_rb32(pb);
467 last_found_pos = avio_tell(pb) - 16 - 6;
468 if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) {
469 if (avio_seek(pb, last_pos, SEEK_SET) >= 0)
474 avio_seek(pb, last_found_pos, SEEK_SET);
475 return cur_timestamp;
478 static int gxf_packet(AVFormatContext *s, AVPacket *pkt) {
479 AVIOContext *pb = s->pb;
482 struct gxf_stream_info *si = s->priv_data;
484 while (!pb->eof_reached) {
486 int track_type, track_id, ret;
487 int field_nr, field_info, skip = 0;
489 if (!parse_packet_header(pb, &pkt_type, &pkt_len)) {
491 av_log(s, AV_LOG_ERROR, "sync lost\n");
494 if (pkt_type == PKT_FLT) {
495 gxf_read_index(s, pkt_len);
498 if (pkt_type != PKT_MEDIA) {
499 avio_skip(pb, pkt_len);
503 av_log(s, AV_LOG_ERROR, "invalid media packet length\n");
507 track_type = avio_r8(pb);
508 track_id = avio_r8(pb);
509 stream_index = get_sindex(s, track_id, track_type);
510 if (stream_index < 0)
512 st = s->streams[stream_index];
513 field_nr = avio_rb32(pb);
514 field_info = avio_rb32(pb);
515 avio_rb32(pb); // "timeline" field number
516 avio_r8(pb); // flags
517 avio_r8(pb); // reserved
518 if (st->codec->codec_id == AV_CODEC_ID_PCM_S24LE ||
519 st->codec->codec_id == AV_CODEC_ID_PCM_S16LE) {
520 int first = field_info >> 16;
521 int last = field_info & 0xffff; // last is exclusive
522 int bps = av_get_bits_per_sample(st->codec->codec_id)>>3;
523 if (first <= last && last*bps <= pkt_len) {
524 avio_skip(pb, first*bps);
525 skip = pkt_len - last*bps;
526 pkt_len = (last-first)*bps;
528 av_log(s, AV_LOG_ERROR, "invalid first and last sample values\n");
530 ret = av_get_packet(pb, pkt, pkt_len);
533 pkt->stream_index = stream_index;
536 //set duration manually for DV or else lavf misdetects the frame rate
537 if (st->codec->codec_id == AV_CODEC_ID_DVVIDEO)
538 pkt->duration = si->fields_per_frame;
545 static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {
548 uint64_t maxlen = 100 * 1024 * 1024;
549 AVStream *st = s->streams[0];
550 int64_t start_time = s->streams[stream_index]->start_time;
553 if (timestamp < start_time) timestamp = start_time;
554 idx = av_index_search_timestamp(st, timestamp - start_time,
555 AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
558 pos = st->index_entries[idx].pos;
559 if (idx < st->nb_index_entries - 2)
560 maxlen = st->index_entries[idx + 2].pos - pos;
561 maxlen = FFMAX(maxlen, 200 * 1024);
562 res = avio_seek(s->pb, pos, SEEK_SET);
565 found = gxf_resync_media(s, maxlen, -1, timestamp);
566 if (FFABS(found - timestamp) > 4)
571 static int64_t gxf_read_timestamp(AVFormatContext *s, int stream_index,
572 int64_t *pos, int64_t pos_limit) {
573 AVIOContext *pb = s->pb;
575 if (avio_seek(pb, *pos, SEEK_SET) < 0)
576 return AV_NOPTS_VALUE;
577 res = gxf_resync_media(s, pos_limit - *pos, -1, -1);
578 *pos = avio_tell(pb);
582 AVInputFormat ff_gxf_demuxer = {
584 .long_name = NULL_IF_CONFIG_SMALL("GXF (General eXchange Format)"),
585 .priv_data_size = sizeof(struct gxf_stream_info),
586 .read_probe = gxf_probe,
587 .read_header = gxf_header,
588 .read_packet = gxf_packet,
589 .read_seek = gxf_seek,
590 .read_timestamp = gxf_read_timestamp,