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"
27 struct gxf_stream_info {
30 AVRational frames_per_second;
31 int32_t fields_per_frame;
32 int64_t track_aux_data;
36 * @brief parse gxf timecode and add it to metadata
38 static int add_timecode_metadata(AVDictionary **pm, const char *key, uint32_t timecode, int fields_per_frame)
41 int field = timecode & 0xff;
42 int frame = fields_per_frame ? field / fields_per_frame : field;
43 int second = (timecode >> 8) & 0xff;
44 int minute = (timecode >> 16) & 0xff;
45 int hour = (timecode >> 24) & 0x1f;
46 int drop = (timecode >> 29) & 1;
47 // bit 30: color_frame, unused
48 // ignore invalid time code
51 snprintf(tmp, sizeof(tmp), "%02d:%02d:%02d%c%02d",
52 hour, minute, second, drop ? ';' : ':', frame);
53 return av_dict_set(pm, key, tmp, 0);
57 * @brief parses a packet header, extracting type and length
58 * @param pb AVIOContext to read header from
59 * @param type detected packet type is stored here
60 * @param length detected packet length, excluding header is stored here
61 * @return 0 if header not found or contains invalid data, 1 otherwise
63 static int parse_packet_header(AVIOContext *pb, GXFPktType *type, int *length) {
69 *length = avio_rb32(pb);
70 if ((*length >> 24) || *length < 16)
75 if (avio_r8(pb) != 0xe1)
77 if (avio_r8(pb) != 0xe2)
83 * @brief check if file starts with a PKT_MAP header
85 static int gxf_probe(AVProbeData *p) {
86 static const uint8_t startcode[] = {0, 0, 0, 0, 1, 0xbc}; // start with map packet
87 static const uint8_t endcode[] = {0, 0, 0, 0, 0xe1, 0xe2};
88 if (!memcmp(p->buf, startcode, sizeof(startcode)) &&
89 !memcmp(&p->buf[16 - sizeof(endcode)], endcode, sizeof(endcode)))
90 return AVPROBE_SCORE_MAX;
95 * @brief gets the stream index for the track with the specified id, creates new
97 * @param id id of stream to find / add
98 * @param format stream format identifier
100 static int get_sindex(AVFormatContext *s, int id, int format) {
103 i = ff_find_stream_index(s, id);
106 st = avformat_new_stream(s, NULL);
108 return AVERROR(ENOMEM);
113 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
114 st->codec->codec_id = CODEC_ID_MJPEG;
118 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
119 st->codec->codec_id = CODEC_ID_DVVIDEO;
123 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
124 st->codec->codec_id = CODEC_ID_DVVIDEO;
129 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
130 st->codec->codec_id = CODEC_ID_MPEG2VIDEO;
131 st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
135 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
136 st->codec->codec_id = CODEC_ID_MPEG1VIDEO;
137 st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
140 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
141 st->codec->codec_id = CODEC_ID_PCM_S24LE;
142 st->codec->channels = 1;
143 st->codec->sample_rate = 48000;
144 st->codec->bit_rate = 3 * 1 * 48000 * 8;
145 st->codec->block_align = 3 * 1;
146 st->codec->bits_per_coded_sample = 24;
149 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
150 st->codec->codec_id = CODEC_ID_PCM_S16LE;
151 st->codec->channels = 1;
152 st->codec->sample_rate = 48000;
153 st->codec->bit_rate = 2 * 1 * 48000 * 8;
154 st->codec->block_align = 2 * 1;
155 st->codec->bits_per_coded_sample = 16;
158 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
159 st->codec->codec_id = CODEC_ID_AC3;
160 st->codec->channels = 2;
161 st->codec->sample_rate = 48000;
167 st->codec->codec_type = AVMEDIA_TYPE_DATA;
168 st->codec->codec_id = CODEC_ID_NONE;
171 st->codec->codec_type = AVMEDIA_TYPE_UNKNOWN;
172 st->codec->codec_id = CODEC_ID_NONE;
175 return s->nb_streams - 1;
179 * @brief filters out interesting tags from material information.
180 * @param len length of tag section, will be adjusted to contain remaining bytes
181 * @param si struct to store collected information into
183 static void gxf_material_tags(AVIOContext *pb, int *len, struct gxf_stream_info *si) {
184 si->first_field = AV_NOPTS_VALUE;
185 si->last_field = AV_NOPTS_VALUE;
187 GXFMatTag tag = avio_r8(pb);
188 int tlen = avio_r8(pb);
194 uint32_t value = avio_rb32(pb);
195 if (tag == MAT_FIRST_FIELD)
196 si->first_field = value;
197 else if (tag == MAT_LAST_FIELD)
198 si->last_field = value;
205 * @brief convert fps tag value to AVRational fps
206 * @param fps fps value from tag
207 * @return fps as AVRational, or 0 / 0 if unknown
209 static AVRational fps_tag2avr(int32_t fps) {
210 extern const AVRational avpriv_frame_rate_tab[];
211 if (fps < 1 || fps > 9) fps = 9;
212 return avpriv_frame_rate_tab[9 - fps]; // values have opposite order
216 * @brief convert UMF attributes flags to AVRational fps
217 * @param flags UMF flags to convert
218 * @return fps as AVRational, or 0 / 0 if unknown
220 static AVRational fps_umf2avr(uint32_t flags) {
221 static const AVRational map[] = {{50, 1}, {60000, 1001}, {24, 1},
222 {25, 1}, {30000, 1001}};
223 int idx = av_log2((flags & 0x7c0) >> 6);
228 * @brief filters out interesting tags from track information.
229 * @param len length of tag section, will be adjusted to contain remaining bytes
230 * @param si struct to store collected information into
232 static void gxf_track_tags(AVIOContext *pb, int *len, struct gxf_stream_info *si) {
233 si->frames_per_second = (AVRational){0, 0};
234 si->fields_per_frame = 0;
235 si->track_aux_data = 0x80000000;
237 GXFTrackTag tag = avio_r8(pb);
238 int tlen = avio_r8(pb);
244 uint32_t value = avio_rb32(pb);
245 if (tag == TRACK_FPS)
246 si->frames_per_second = fps_tag2avr(value);
247 else if (tag == TRACK_FPF && (value == 1 || value == 2))
248 si->fields_per_frame = value;
249 } else if (tlen == 8 && tag == TRACK_AUX)
250 si->track_aux_data = avio_rl64(pb);
257 * @brief read index from FLT packet into stream 0 av_index
259 static void gxf_read_index(AVFormatContext *s, int pkt_len) {
260 AVIOContext *pb = s->pb;
261 AVStream *st = s->streams[0];
262 uint32_t fields_per_map = avio_rl32(pb);
263 uint32_t map_cnt = avio_rl32(pb);
266 if (s->flags & AVFMT_FLAG_IGNIDX) {
267 avio_skip(pb, pkt_len);
270 if (map_cnt > 1000) {
271 av_log(s, AV_LOG_ERROR, "too many index entries %u (%x)\n", map_cnt, map_cnt);
274 if (pkt_len < 4 * map_cnt) {
275 av_log(s, AV_LOG_ERROR, "invalid index length\n");
276 avio_skip(pb, pkt_len);
279 pkt_len -= 4 * map_cnt;
280 av_add_index_entry(st, 0, 0, 0, 0, 0);
281 for (i = 0; i < map_cnt; i++)
282 av_add_index_entry(st, (uint64_t)avio_rl32(pb) * 1024,
283 i * (uint64_t)fields_per_map + 1, 0, 0, 0);
284 avio_skip(pb, pkt_len);
287 static int gxf_header(AVFormatContext *s) {
288 AVIOContext *pb = s->pb;
292 AVRational main_timebase = {0, 0};
293 struct gxf_stream_info *si = s->priv_data;
295 if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) {
296 av_log(s, AV_LOG_ERROR, "map packet not found\n");
300 if (avio_r8(pb) != 0x0e0 || avio_r8(pb) != 0xff) {
301 av_log(s, AV_LOG_ERROR, "unknown version or invalid map preamble\n");
305 len = avio_rb16(pb); // length of material data section
307 av_log(s, AV_LOG_ERROR, "material data longer than map data\n");
311 gxf_material_tags(pb, &len, si);
314 len = avio_rb16(pb); // length of track description
316 av_log(s, AV_LOG_ERROR, "track description longer than map data\n");
321 int track_type, track_id, track_len;
325 track_type = avio_r8(pb);
326 track_id = avio_r8(pb);
327 track_len = avio_rb16(pb);
329 if (!(track_type & 0x80)) {
330 av_log(s, AV_LOG_ERROR, "invalid track type %x\n", track_type);
334 if ((track_id & 0xc0) != 0xc0) {
335 av_log(s, AV_LOG_ERROR, "invalid track id %x\n", track_id);
339 gxf_track_tags(pb, &track_len, si);
340 // check for timecode tracks
341 if (track_type == 7 || track_type == 8 || track_type == 24) {
342 add_timecode_metadata(&s->metadata, "timecode",
343 si->track_aux_data & 0xffffffff,
344 si->fields_per_frame);
347 avio_skip(pb, track_len);
349 idx = get_sindex(s, track_id, track_type);
350 if (idx < 0) continue;
351 st = s->streams[idx];
352 if (!main_timebase.num || !main_timebase.den) {
353 main_timebase.num = si->frames_per_second.den;
354 main_timebase.den = si->frames_per_second.num * 2;
356 st->start_time = si->first_field;
357 if (si->first_field != AV_NOPTS_VALUE && si->last_field != AV_NOPTS_VALUE)
358 st->duration = si->last_field - si->first_field;
361 av_log(s, AV_LOG_ERROR, "invalid track description length specified\n");
363 avio_skip(pb, map_len);
364 if (!parse_packet_header(pb, &pkt_type, &len)) {
365 av_log(s, AV_LOG_ERROR, "sync lost in header\n");
368 if (pkt_type == PKT_FLT) {
369 gxf_read_index(s, len);
370 if (!parse_packet_header(pb, &pkt_type, &len)) {
371 av_log(s, AV_LOG_ERROR, "sync lost in header\n");
375 if (pkt_type == PKT_UMF) {
379 avio_skip(pb, 5); // preamble
380 avio_skip(pb, 0x30); // payload description
381 fps = fps_umf2avr(avio_rl32(pb));
382 if (!main_timebase.num || !main_timebase.den) {
383 av_log(s, AV_LOG_WARNING, "No FPS track tag, using UMF fps tag."
384 " This might give wrong results.\n");
385 // this may not always be correct, but simply the best we can get
386 main_timebase.num = fps.den;
387 main_timebase.den = fps.num * 2;
393 add_timecode_metadata(&s->metadata, "timecode_at_mark_in",
394 avio_rl32(pb), si->fields_per_frame);
395 add_timecode_metadata(&s->metadata, "timecode_at_mark_out",
396 avio_rl32(pb), si->fields_per_frame);
399 av_log(s, AV_LOG_INFO, "UMF packet too short\n");
401 av_log(s, AV_LOG_INFO, "UMF packet missing\n");
403 // set a fallback value, 60000/1001 is specified for audio-only files
404 // so use that regardless of why we do not know the video frame rate.
405 if (!main_timebase.num || !main_timebase.den)
406 main_timebase = (AVRational){1001, 60000};
407 for (i = 0; i < s->nb_streams; i++) {
408 AVStream *st = s->streams[i];
409 avpriv_set_pts_info(st, 32, main_timebase.num, main_timebase.den);
416 if (!max_interval-- || url_feof(pb)) \
418 tmp = tmp << 8 | avio_r8(pb); \
422 * @brief resync the stream on the next media packet with specified properties
423 * @param max_interval how many bytes to search for matching packet at most
424 * @param track track id the media packet must belong to, -1 for any
425 * @param timestamp minimum timestamp (== field number) the packet must have, -1 for any
426 * @return timestamp of packet found
428 static int64_t gxf_resync_media(AVFormatContext *s, uint64_t max_interval, int track, int timestamp) {
431 uint64_t last_found_pos = 0;
433 int64_t cur_timestamp = AV_NOPTS_VALUE;
435 AVIOContext *pb = s->pb;
444 last_pos = avio_tell(pb);
445 if (avio_seek(pb, -5, SEEK_CUR) < 0)
447 if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) {
448 if (avio_seek(pb, last_pos, SEEK_SET) < 0)
453 cur_track = avio_r8(pb);
454 cur_timestamp = avio_rb32(pb);
455 last_found_pos = avio_tell(pb) - 16 - 6;
456 if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) {
457 if (avio_seek(pb, last_pos, SEEK_SET) >= 0)
462 avio_seek(pb, last_found_pos, SEEK_SET);
463 return cur_timestamp;
466 static int gxf_packet(AVFormatContext *s, AVPacket *pkt) {
467 AVIOContext *pb = s->pb;
470 struct gxf_stream_info *si = s->priv_data;
472 while (!pb->eof_reached) {
474 int track_type, track_id, ret;
475 int field_nr, field_info, skip = 0;
477 if (!parse_packet_header(pb, &pkt_type, &pkt_len)) {
479 av_log(s, AV_LOG_ERROR, "sync lost\n");
482 if (pkt_type == PKT_FLT) {
483 gxf_read_index(s, pkt_len);
486 if (pkt_type != PKT_MEDIA) {
487 avio_skip(pb, pkt_len);
491 av_log(s, AV_LOG_ERROR, "invalid media packet length\n");
495 track_type = avio_r8(pb);
496 track_id = avio_r8(pb);
497 stream_index = get_sindex(s, track_id, track_type);
498 if (stream_index < 0)
500 st = s->streams[stream_index];
501 field_nr = avio_rb32(pb);
502 field_info = avio_rb32(pb);
503 avio_rb32(pb); // "timeline" field number
504 avio_r8(pb); // flags
505 avio_r8(pb); // reserved
506 if (st->codec->codec_id == CODEC_ID_PCM_S24LE ||
507 st->codec->codec_id == CODEC_ID_PCM_S16LE) {
508 int first = field_info >> 16;
509 int last = field_info & 0xffff; // last is exclusive
510 int bps = av_get_bits_per_sample(st->codec->codec_id)>>3;
511 if (first <= last && last*bps <= pkt_len) {
512 avio_skip(pb, first*bps);
513 skip = pkt_len - last*bps;
514 pkt_len = (last-first)*bps;
516 av_log(s, AV_LOG_ERROR, "invalid first and last sample values\n");
518 ret = av_get_packet(pb, pkt, pkt_len);
521 pkt->stream_index = stream_index;
524 //set duration manually for DV or else lavf misdetects the frame rate
525 if (st->codec->codec_id == CODEC_ID_DVVIDEO)
526 pkt->duration = si->fields_per_frame;
533 static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {
536 uint64_t maxlen = 100 * 1024 * 1024;
537 AVStream *st = s->streams[0];
538 int64_t start_time = s->streams[stream_index]->start_time;
541 if (timestamp < start_time) timestamp = start_time;
542 idx = av_index_search_timestamp(st, timestamp - start_time,
543 AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
546 pos = st->index_entries[idx].pos;
547 if (idx < st->nb_index_entries - 2)
548 maxlen = st->index_entries[idx + 2].pos - pos;
549 maxlen = FFMAX(maxlen, 200 * 1024);
550 res = avio_seek(s->pb, pos, SEEK_SET);
553 found = gxf_resync_media(s, maxlen, -1, timestamp);
554 if (FFABS(found - timestamp) > 4)
559 static int64_t gxf_read_timestamp(AVFormatContext *s, int stream_index,
560 int64_t *pos, int64_t pos_limit) {
561 AVIOContext *pb = s->pb;
563 if (avio_seek(pb, *pos, SEEK_SET) < 0)
564 return AV_NOPTS_VALUE;
565 res = gxf_resync_media(s, pos_limit - *pos, -1, -1);
566 *pos = avio_tell(pb);
570 AVInputFormat ff_gxf_demuxer = {
572 .long_name = NULL_IF_CONFIG_SMALL("GXF format"),
573 .priv_data_size = sizeof(struct gxf_stream_info),
574 .read_probe = gxf_probe,
575 .read_header = gxf_header,
576 .read_packet = gxf_packet,
577 .read_seek = gxf_seek,
578 .read_timestamp = gxf_read_timestamp,