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/channel_layout.h"
23 #include "libavutil/common.h"
27 #include "libavcodec/mpeg12data.h"
29 struct gxf_stream_info {
32 AVRational frames_per_second;
33 int32_t fields_per_frame;
34 int64_t track_aux_data;
38 * @brief parse gxf timecode and add it to metadata
40 static int add_timecode_metadata(AVDictionary **pm, const char *key, uint32_t timecode, int fields_per_frame)
43 int field = timecode & 0xff;
44 int frame = fields_per_frame ? field / fields_per_frame : field;
45 int second = (timecode >> 8) & 0xff;
46 int minute = (timecode >> 16) & 0xff;
47 int hour = (timecode >> 24) & 0x1f;
48 int drop = (timecode >> 29) & 1;
49 // bit 30: color_frame, unused
50 // ignore invalid time code
53 snprintf(tmp, sizeof(tmp), "%02d:%02d:%02d%c%02d",
54 hour, minute, second, drop ? ';' : ':', frame);
55 return av_dict_set(pm, key, tmp, 0);
59 * @brief parses a packet header, extracting type and length
60 * @param pb AVIOContext to read header from
61 * @param type detected packet type is stored here
62 * @param length detected packet length, excluding header is stored here
63 * @return 0 if header not found or contains invalid data, 1 otherwise
65 static int parse_packet_header(AVIOContext *pb, GXFPktType *type, int *length) {
71 *length = avio_rb32(pb);
72 if ((*length >> 24) || *length < 16)
77 if (avio_r8(pb) != 0xe1)
79 if (avio_r8(pb) != 0xe2)
85 * @brief check if file starts with a PKT_MAP header
87 static int gxf_probe(AVProbeData *p) {
88 static const uint8_t startcode[] = {0, 0, 0, 0, 1, 0xbc}; // start with map packet
89 static const uint8_t endcode[] = {0, 0, 0, 0, 0xe1, 0xe2};
90 if (!memcmp(p->buf, startcode, sizeof(startcode)) &&
91 !memcmp(&p->buf[16 - sizeof(endcode)], endcode, sizeof(endcode)))
92 return AVPROBE_SCORE_MAX;
97 * @brief gets the stream index for the track with the specified id, creates new
99 * @param id id of stream to find / add
100 * @param format stream format identifier
102 static int get_sindex(AVFormatContext *s, int id, int format) {
105 i = ff_find_stream_index(s, id);
108 st = avformat_new_stream(s, NULL);
110 return AVERROR(ENOMEM);
115 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
116 st->codec->codec_id = AV_CODEC_ID_MJPEG;
120 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
121 st->codec->codec_id = AV_CODEC_ID_DVVIDEO;
125 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
126 st->codec->codec_id = AV_CODEC_ID_DVVIDEO;
131 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
132 st->codec->codec_id = AV_CODEC_ID_MPEG2VIDEO;
133 st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
137 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
138 st->codec->codec_id = AV_CODEC_ID_MPEG1VIDEO;
139 st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
142 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
143 st->codec->codec_id = AV_CODEC_ID_PCM_S24LE;
144 st->codec->channels = 1;
145 st->codec->channel_layout = AV_CH_LAYOUT_MONO;
146 st->codec->sample_rate = 48000;
147 st->codec->bit_rate = 3 * 1 * 48000 * 8;
148 st->codec->block_align = 3 * 1;
149 st->codec->bits_per_coded_sample = 24;
152 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
153 st->codec->codec_id = AV_CODEC_ID_PCM_S16LE;
154 st->codec->channels = 1;
155 st->codec->channel_layout = AV_CH_LAYOUT_MONO;
156 st->codec->sample_rate = 48000;
157 st->codec->bit_rate = 2 * 1 * 48000 * 8;
158 st->codec->block_align = 2 * 1;
159 st->codec->bits_per_coded_sample = 16;
162 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
163 st->codec->codec_id = AV_CODEC_ID_AC3;
164 st->codec->channels = 2;
165 st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
166 st->codec->sample_rate = 48000;
172 st->codec->codec_type = AVMEDIA_TYPE_DATA;
173 st->codec->codec_id = AV_CODEC_ID_NONE;
176 st->codec->codec_type = AVMEDIA_TYPE_UNKNOWN;
177 st->codec->codec_id = AV_CODEC_ID_NONE;
180 return s->nb_streams - 1;
184 * @brief filters out interesting tags from material information.
185 * @param len length of tag section, will be adjusted to contain remaining bytes
186 * @param si struct to store collected information into
188 static void gxf_material_tags(AVIOContext *pb, int *len, struct gxf_stream_info *si) {
189 si->first_field = AV_NOPTS_VALUE;
190 si->last_field = AV_NOPTS_VALUE;
192 GXFMatTag tag = avio_r8(pb);
193 int tlen = avio_r8(pb);
199 uint32_t value = avio_rb32(pb);
200 if (tag == MAT_FIRST_FIELD)
201 si->first_field = value;
202 else if (tag == MAT_LAST_FIELD)
203 si->last_field = value;
209 static const AVRational frame_rate_tab[] = {
222 * @brief convert fps tag value to AVRational fps
223 * @param fps fps value from tag
224 * @return fps as AVRational, or 0 / 0 if unknown
226 static AVRational fps_tag2avr(int32_t fps) {
227 if (fps < 1 || fps > 9) fps = 9;
228 return frame_rate_tab[fps - 1];
232 * @brief convert UMF attributes flags to AVRational fps
233 * @param flags UMF flags to convert
234 * @return fps as AVRational, or 0 / 0 if unknown
236 static AVRational fps_umf2avr(uint32_t flags) {
237 static const AVRational map[] = {{50, 1}, {60000, 1001}, {24, 1},
238 {25, 1}, {30000, 1001}};
239 int idx = av_log2((flags & 0x7c0) >> 6);
244 * @brief filters out interesting tags from track information.
245 * @param len length of tag section, will be adjusted to contain remaining bytes
246 * @param si struct to store collected information into
248 static void gxf_track_tags(AVIOContext *pb, int *len, struct gxf_stream_info *si) {
249 si->frames_per_second = (AVRational){0, 0};
250 si->fields_per_frame = 0;
251 si->track_aux_data = 0x80000000;
253 GXFTrackTag tag = avio_r8(pb);
254 int tlen = avio_r8(pb);
260 uint32_t value = avio_rb32(pb);
261 if (tag == TRACK_FPS)
262 si->frames_per_second = fps_tag2avr(value);
263 else if (tag == TRACK_FPF && (value == 1 || value == 2))
264 si->fields_per_frame = value;
265 } else if (tlen == 8 && tag == TRACK_AUX)
266 si->track_aux_data = avio_rl64(pb);
273 * @brief read index from FLT packet into stream 0 av_index
275 static void gxf_read_index(AVFormatContext *s, int pkt_len) {
276 AVIOContext *pb = s->pb;
278 uint32_t fields_per_map = avio_rl32(pb);
279 uint32_t map_cnt = avio_rl32(pb);
282 if ((s->flags & AVFMT_FLAG_IGNIDX) || !s->streams) {
283 avio_skip(pb, pkt_len);
287 if (map_cnt > 1000) {
288 av_log(s, AV_LOG_ERROR, "too many index entries %u (%x)\n", map_cnt, map_cnt);
291 if (pkt_len < 4 * map_cnt) {
292 av_log(s, AV_LOG_ERROR, "invalid index length\n");
293 avio_skip(pb, pkt_len);
296 pkt_len -= 4 * map_cnt;
297 av_add_index_entry(st, 0, 0, 0, 0, 0);
298 for (i = 0; i < map_cnt; i++)
299 av_add_index_entry(st, (uint64_t)avio_rl32(pb) * 1024,
300 i * (uint64_t)fields_per_map + 1, 0, 0, 0);
301 avio_skip(pb, pkt_len);
304 static int gxf_header(AVFormatContext *s) {
305 AVIOContext *pb = s->pb;
309 AVRational main_timebase = {0, 0};
310 struct gxf_stream_info *si = s->priv_data;
312 if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) {
313 av_log(s, AV_LOG_ERROR, "map packet not found\n");
317 if (avio_r8(pb) != 0x0e0 || avio_r8(pb) != 0xff) {
318 av_log(s, AV_LOG_ERROR, "unknown version or invalid map preamble\n");
322 len = avio_rb16(pb); // length of material data section
324 av_log(s, AV_LOG_ERROR, "material data longer than map data\n");
328 gxf_material_tags(pb, &len, si);
331 len = avio_rb16(pb); // length of track description
333 av_log(s, AV_LOG_ERROR, "track description longer than map data\n");
338 int track_type, track_id, track_len;
342 track_type = avio_r8(pb);
343 track_id = avio_r8(pb);
344 track_len = avio_rb16(pb);
346 if (!(track_type & 0x80)) {
347 av_log(s, AV_LOG_ERROR, "invalid track type %x\n", track_type);
351 if ((track_id & 0xc0) != 0xc0) {
352 av_log(s, AV_LOG_ERROR, "invalid track id %x\n", track_id);
356 gxf_track_tags(pb, &track_len, si);
357 // check for timecode tracks
358 if (track_type == 7 || track_type == 8 || track_type == 24) {
359 add_timecode_metadata(&s->metadata, "timecode",
360 si->track_aux_data & 0xffffffff,
361 si->fields_per_frame);
364 avio_skip(pb, track_len);
366 idx = get_sindex(s, track_id, track_type);
367 if (idx < 0) continue;
368 st = s->streams[idx];
369 if (!main_timebase.num || !main_timebase.den) {
370 main_timebase.num = si->frames_per_second.den;
371 main_timebase.den = si->frames_per_second.num * 2;
373 st->start_time = si->first_field;
374 if (si->first_field != AV_NOPTS_VALUE && si->last_field != AV_NOPTS_VALUE)
375 st->duration = si->last_field - si->first_field;
378 av_log(s, AV_LOG_ERROR, "invalid track description length specified\n");
380 avio_skip(pb, map_len);
381 if (!parse_packet_header(pb, &pkt_type, &len)) {
382 av_log(s, AV_LOG_ERROR, "sync lost in header\n");
385 if (pkt_type == PKT_FLT) {
386 gxf_read_index(s, len);
387 if (!parse_packet_header(pb, &pkt_type, &len)) {
388 av_log(s, AV_LOG_ERROR, "sync lost in header\n");
392 if (pkt_type == PKT_UMF) {
396 avio_skip(pb, 5); // preamble
397 avio_skip(pb, 0x30); // payload description
398 fps = fps_umf2avr(avio_rl32(pb));
399 if (!main_timebase.num || !main_timebase.den) {
400 av_log(s, AV_LOG_WARNING, "No FPS track tag, using UMF fps tag."
401 " This might give wrong results.\n");
402 // this may not always be correct, but simply the best we can get
403 main_timebase.num = fps.den;
404 main_timebase.den = fps.num * 2;
410 add_timecode_metadata(&s->metadata, "timecode_at_mark_in",
411 avio_rl32(pb), si->fields_per_frame);
412 add_timecode_metadata(&s->metadata, "timecode_at_mark_out",
413 avio_rl32(pb), si->fields_per_frame);
416 av_log(s, AV_LOG_INFO, "UMF packet too short\n");
418 av_log(s, AV_LOG_INFO, "UMF packet missing\n");
420 // set a fallback value, 60000/1001 is specified for audio-only files
421 // so use that regardless of why we do not know the video frame rate.
422 if (!main_timebase.num || !main_timebase.den)
423 main_timebase = (AVRational){1001, 60000};
424 for (i = 0; i < s->nb_streams; i++) {
425 AVStream *st = s->streams[i];
426 avpriv_set_pts_info(st, 32, main_timebase.num, main_timebase.den);
433 if (!max_interval-- || url_feof(pb)) \
435 tmp = tmp << 8 | avio_r8(pb); \
439 * @brief resync the stream on the next media packet with specified properties
440 * @param max_interval how many bytes to search for matching packet at most
441 * @param track track id the media packet must belong to, -1 for any
442 * @param timestamp minimum timestamp (== field number) the packet must have, -1 for any
443 * @return timestamp of packet found
445 static int64_t gxf_resync_media(AVFormatContext *s, uint64_t max_interval, int track, int timestamp) {
448 uint64_t last_found_pos = 0;
450 int64_t cur_timestamp = AV_NOPTS_VALUE;
452 AVIOContext *pb = s->pb;
461 last_pos = avio_tell(pb);
462 if (avio_seek(pb, -5, SEEK_CUR) < 0)
464 if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) {
465 if (avio_seek(pb, last_pos, SEEK_SET) < 0)
470 cur_track = avio_r8(pb);
471 cur_timestamp = avio_rb32(pb);
472 last_found_pos = avio_tell(pb) - 16 - 6;
473 if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) {
474 if (avio_seek(pb, last_pos, SEEK_SET) >= 0)
479 avio_seek(pb, last_found_pos, SEEK_SET);
480 return cur_timestamp;
483 static int gxf_packet(AVFormatContext *s, AVPacket *pkt) {
484 AVIOContext *pb = s->pb;
487 struct gxf_stream_info *si = s->priv_data;
489 while (!pb->eof_reached) {
491 int track_type, track_id, ret;
492 int field_nr, field_info, skip = 0;
494 if (!parse_packet_header(pb, &pkt_type, &pkt_len)) {
496 av_log(s, AV_LOG_ERROR, "sync lost\n");
499 if (pkt_type == PKT_FLT) {
500 gxf_read_index(s, pkt_len);
503 if (pkt_type != PKT_MEDIA) {
504 avio_skip(pb, pkt_len);
508 av_log(s, AV_LOG_ERROR, "invalid media packet length\n");
512 track_type = avio_r8(pb);
513 track_id = avio_r8(pb);
514 stream_index = get_sindex(s, track_id, track_type);
515 if (stream_index < 0)
517 st = s->streams[stream_index];
518 field_nr = avio_rb32(pb);
519 field_info = avio_rb32(pb);
520 avio_rb32(pb); // "timeline" field number
521 avio_r8(pb); // flags
522 avio_r8(pb); // reserved
523 if (st->codec->codec_id == AV_CODEC_ID_PCM_S24LE ||
524 st->codec->codec_id == AV_CODEC_ID_PCM_S16LE) {
525 int first = field_info >> 16;
526 int last = field_info & 0xffff; // last is exclusive
527 int bps = av_get_bits_per_sample(st->codec->codec_id)>>3;
528 if (first <= last && last*bps <= pkt_len) {
529 avio_skip(pb, first*bps);
530 skip = pkt_len - last*bps;
531 pkt_len = (last-first)*bps;
533 av_log(s, AV_LOG_ERROR, "invalid first and last sample values\n");
535 ret = av_get_packet(pb, pkt, pkt_len);
538 pkt->stream_index = stream_index;
541 //set duration manually for DV or else lavf misdetects the frame rate
542 if (st->codec->codec_id == AV_CODEC_ID_DVVIDEO)
543 pkt->duration = si->fields_per_frame;
550 static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {
553 uint64_t maxlen = 100 * 1024 * 1024;
554 AVStream *st = s->streams[0];
555 int64_t start_time = s->streams[stream_index]->start_time;
558 if (timestamp < start_time) timestamp = start_time;
559 idx = av_index_search_timestamp(st, timestamp - start_time,
560 AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
563 pos = st->index_entries[idx].pos;
564 if (idx < st->nb_index_entries - 2)
565 maxlen = st->index_entries[idx + 2].pos - pos;
566 maxlen = FFMAX(maxlen, 200 * 1024);
567 res = avio_seek(s->pb, pos, SEEK_SET);
570 found = gxf_resync_media(s, maxlen, -1, timestamp);
571 if (FFABS(found - timestamp) > 4)
576 static int64_t gxf_read_timestamp(AVFormatContext *s, int stream_index,
577 int64_t *pos, int64_t pos_limit) {
578 AVIOContext *pb = s->pb;
580 if (avio_seek(pb, *pos, SEEK_SET) < 0)
581 return AV_NOPTS_VALUE;
582 res = gxf_resync_media(s, pos_limit - *pos, -1, -1);
583 *pos = avio_tell(pb);
587 AVInputFormat ff_gxf_demuxer = {
589 .long_name = NULL_IF_CONFIG_SMALL("GXF (General eXchange Format)"),
590 .priv_data_size = sizeof(struct gxf_stream_info),
591 .read_probe = gxf_probe,
592 .read_header = gxf_header,
593 .read_packet = gxf_packet,
594 .read_seek = gxf_seek,
595 .read_timestamp = gxf_read_timestamp,