3 * Copyright (c) 2006 Reimar Doeffinger
5 * This file is part of Libav.
7 * Libav 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 * Libav 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 Libav; 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;
37 * @brief parses a packet header, extracting type and length
38 * @param pb AVIOContext to read header from
39 * @param type detected packet type is stored here
40 * @param length detected packet length, excluding header is stored here
41 * @return 0 if header not found or contains invalid data, 1 otherwise
43 static int parse_packet_header(AVIOContext *pb, GXFPktType *type, int *length) {
49 *length = avio_rb32(pb);
50 if ((*length >> 24) || *length < 16)
55 if (avio_r8(pb) != 0xe1)
57 if (avio_r8(pb) != 0xe2)
63 * @brief check if file starts with a PKT_MAP header
65 static int gxf_probe(AVProbeData *p) {
66 static const uint8_t startcode[] = {0, 0, 0, 0, 1, 0xbc}; // start with map packet
67 static const uint8_t endcode[] = {0, 0, 0, 0, 0xe1, 0xe2};
68 if (!memcmp(p->buf, startcode, sizeof(startcode)) &&
69 !memcmp(&p->buf[16 - sizeof(endcode)], endcode, sizeof(endcode)))
70 return AVPROBE_SCORE_MAX;
75 * @brief gets the stream index for the track with the specified id, creates new
77 * @param id id of stream to find / add
78 * @param format stream format identifier
80 static int get_sindex(AVFormatContext *s, int id, int format) {
83 i = ff_find_stream_index(s, id);
86 st = avformat_new_stream(s, NULL);
88 return AVERROR(ENOMEM);
93 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
94 st->codec->codec_id = AV_CODEC_ID_MJPEG;
98 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
99 st->codec->codec_id = AV_CODEC_ID_DVVIDEO;
103 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
104 st->codec->codec_id = AV_CODEC_ID_DVVIDEO;
109 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
110 st->codec->codec_id = AV_CODEC_ID_MPEG2VIDEO;
111 st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
115 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
116 st->codec->codec_id = AV_CODEC_ID_MPEG1VIDEO;
117 st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
120 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
121 st->codec->codec_id = AV_CODEC_ID_PCM_S24LE;
122 st->codec->channels = 1;
123 st->codec->channel_layout = AV_CH_LAYOUT_MONO;
124 st->codec->sample_rate = 48000;
125 st->codec->bit_rate = 3 * 1 * 48000 * 8;
126 st->codec->block_align = 3 * 1;
127 st->codec->bits_per_coded_sample = 24;
130 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
131 st->codec->codec_id = AV_CODEC_ID_PCM_S16LE;
132 st->codec->channels = 1;
133 st->codec->channel_layout = AV_CH_LAYOUT_MONO;
134 st->codec->sample_rate = 48000;
135 st->codec->bit_rate = 2 * 1 * 48000 * 8;
136 st->codec->block_align = 2 * 1;
137 st->codec->bits_per_coded_sample = 16;
140 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
141 st->codec->codec_id = AV_CODEC_ID_AC3;
142 st->codec->channels = 2;
143 st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
144 st->codec->sample_rate = 48000;
150 st->codec->codec_type = AVMEDIA_TYPE_DATA;
151 st->codec->codec_id = AV_CODEC_ID_NONE;
154 st->codec->codec_type = AVMEDIA_TYPE_UNKNOWN;
155 st->codec->codec_id = AV_CODEC_ID_NONE;
158 return s->nb_streams - 1;
162 * @brief filters out interesting tags from material information.
163 * @param len length of tag section, will be adjusted to contain remaining bytes
164 * @param si struct to store collected information into
166 static void gxf_material_tags(AVIOContext *pb, int *len, struct gxf_stream_info *si) {
167 si->first_field = AV_NOPTS_VALUE;
168 si->last_field = AV_NOPTS_VALUE;
170 GXFMatTag tag = avio_r8(pb);
171 int tlen = avio_r8(pb);
177 uint32_t value = avio_rb32(pb);
178 if (tag == MAT_FIRST_FIELD)
179 si->first_field = value;
180 else if (tag == MAT_LAST_FIELD)
181 si->last_field = value;
187 static const AVRational frame_rate_tab[] = {
200 * @brief convert fps tag value to AVRational fps
201 * @param fps fps value from tag
202 * @return fps as AVRational, or 0 / 0 if unknown
204 static AVRational fps_tag2avr(int32_t fps) {
205 if (fps < 1 || fps > 9) fps = 9;
206 return frame_rate_tab[fps - 1];
210 * @brief convert UMF attributes flags to AVRational fps
211 * @param flags UMF flags to convert
212 * @return fps as AVRational, or 0 / 0 if unknown
214 static AVRational fps_umf2avr(uint32_t flags) {
215 static const AVRational map[] = {{50, 1}, {60000, 1001}, {24, 1},
216 {25, 1}, {30000, 1001}};
217 int idx = av_log2((flags & 0x7c0) >> 6);
222 * @brief filters out interesting tags from track information.
223 * @param len length of tag section, will be adjusted to contain remaining bytes
224 * @param si struct to store collected information into
226 static void gxf_track_tags(AVIOContext *pb, int *len, struct gxf_stream_info *si) {
227 si->frames_per_second = (AVRational){0, 0};
228 si->fields_per_frame = 0;
230 GXFTrackTag tag = avio_r8(pb);
231 int tlen = avio_r8(pb);
237 uint32_t value = avio_rb32(pb);
238 if (tag == TRACK_FPS)
239 si->frames_per_second = fps_tag2avr(value);
240 else if (tag == TRACK_FPF && (value == 1 || value == 2))
241 si->fields_per_frame = value;
248 * @brief read index from FLT packet into stream 0 av_index
250 static void gxf_read_index(AVFormatContext *s, int pkt_len) {
251 AVIOContext *pb = s->pb;
252 AVStream *st = s->streams[0];
253 uint32_t fields_per_map = avio_rl32(pb);
254 uint32_t map_cnt = avio_rl32(pb);
257 if (s->flags & AVFMT_FLAG_IGNIDX) {
258 avio_skip(pb, pkt_len);
261 if (map_cnt > 1000) {
262 av_log(s, AV_LOG_ERROR, "too many index entries %u (%x)\n", map_cnt, map_cnt);
265 if (pkt_len < 4 * map_cnt) {
266 av_log(s, AV_LOG_ERROR, "invalid index length\n");
267 avio_skip(pb, pkt_len);
270 pkt_len -= 4 * map_cnt;
271 av_add_index_entry(st, 0, 0, 0, 0, 0);
272 for (i = 0; i < map_cnt; i++)
273 av_add_index_entry(st, (uint64_t)avio_rl32(pb) * 1024,
274 i * (uint64_t)fields_per_map + 1, 0, 0, 0);
275 avio_skip(pb, pkt_len);
278 static int gxf_header(AVFormatContext *s) {
279 AVIOContext *pb = s->pb;
283 AVRational main_timebase = {0, 0};
284 struct gxf_stream_info *si = s->priv_data;
286 if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) {
287 av_log(s, AV_LOG_ERROR, "map packet not found\n");
291 if (avio_r8(pb) != 0x0e0 || avio_r8(pb) != 0xff) {
292 av_log(s, AV_LOG_ERROR, "unknown version or invalid map preamble\n");
296 len = avio_rb16(pb); // length of material data section
298 av_log(s, AV_LOG_ERROR, "material data longer than map data\n");
302 gxf_material_tags(pb, &len, si);
305 len = avio_rb16(pb); // length of track description
307 av_log(s, AV_LOG_ERROR, "track description longer than map data\n");
312 int track_type, track_id, track_len;
316 track_type = avio_r8(pb);
317 track_id = avio_r8(pb);
318 track_len = avio_rb16(pb);
320 gxf_track_tags(pb, &track_len, si);
321 avio_skip(pb, track_len);
322 if (!(track_type & 0x80)) {
323 av_log(s, AV_LOG_ERROR, "invalid track type %x\n", track_type);
327 if ((track_id & 0xc0) != 0xc0) {
328 av_log(s, AV_LOG_ERROR, "invalid track id %x\n", track_id);
332 idx = get_sindex(s, track_id, track_type);
333 if (idx < 0) continue;
334 st = s->streams[idx];
335 if (!main_timebase.num || !main_timebase.den) {
336 main_timebase.num = si->frames_per_second.den;
337 main_timebase.den = si->frames_per_second.num * 2;
339 st->start_time = si->first_field;
340 if (si->first_field != AV_NOPTS_VALUE && si->last_field != AV_NOPTS_VALUE)
341 st->duration = si->last_field - si->first_field;
344 av_log(s, AV_LOG_ERROR, "invalid track description length specified\n");
346 avio_skip(pb, map_len);
347 if (!parse_packet_header(pb, &pkt_type, &len)) {
348 av_log(s, AV_LOG_ERROR, "sync lost in header\n");
351 if (pkt_type == PKT_FLT) {
352 gxf_read_index(s, len);
353 if (!parse_packet_header(pb, &pkt_type, &len)) {
354 av_log(s, AV_LOG_ERROR, "sync lost in header\n");
358 if (pkt_type == PKT_UMF) {
362 avio_skip(pb, 5); // preamble
363 avio_skip(pb, 0x30); // payload description
364 fps = fps_umf2avr(avio_rl32(pb));
365 if (!main_timebase.num || !main_timebase.den) {
366 // this may not always be correct, but simply the best we can get
367 main_timebase.num = fps.den;
368 main_timebase.den = fps.num * 2;
371 av_log(s, AV_LOG_INFO, "UMF packet too short\n");
373 av_log(s, AV_LOG_INFO, "UMF packet missing\n");
375 // set a fallback value, 60000/1001 is specified for audio-only files
376 // so use that regardless of why we do not know the video frame rate.
377 if (!main_timebase.num || !main_timebase.den)
378 main_timebase = (AVRational){1001, 60000};
379 for (i = 0; i < s->nb_streams; i++) {
380 AVStream *st = s->streams[i];
381 avpriv_set_pts_info(st, 32, main_timebase.num, main_timebase.den);
388 if (!max_interval-- || pb->eof_reached) \
390 tmp = tmp << 8 | avio_r8(pb); \
394 * @brief resync the stream on the next media packet with specified properties
395 * @param max_interval how many bytes to search for matching packet at most
396 * @param track track id the media packet must belong to, -1 for any
397 * @param timestamp minimum timestamp (== field number) the packet must have, -1 for any
398 * @return timestamp of packet found
400 static int64_t gxf_resync_media(AVFormatContext *s, uint64_t max_interval, int track, int timestamp) {
403 uint64_t last_found_pos = 0;
405 int64_t cur_timestamp = AV_NOPTS_VALUE;
407 AVIOContext *pb = s->pb;
416 last_pos = avio_tell(pb);
417 if (avio_seek(pb, -5, SEEK_CUR) < 0)
419 if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) {
420 if (avio_seek(pb, last_pos, SEEK_SET) < 0)
425 cur_track = avio_r8(pb);
426 cur_timestamp = avio_rb32(pb);
427 last_found_pos = avio_tell(pb) - 16 - 6;
428 if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) {
429 if (avio_seek(pb, last_pos, SEEK_SET) >= 0)
434 avio_seek(pb, last_found_pos, SEEK_SET);
435 return cur_timestamp;
438 static int gxf_packet(AVFormatContext *s, AVPacket *pkt) {
439 AVIOContext *pb = s->pb;
442 struct gxf_stream_info *si = s->priv_data;
444 while (!pb->eof_reached) {
446 int track_type, track_id, ret;
447 int field_nr, field_info, skip = 0;
449 if (!parse_packet_header(pb, &pkt_type, &pkt_len)) {
450 if (!pb->eof_reached)
451 av_log(s, AV_LOG_ERROR, "sync lost\n");
454 if (pkt_type == PKT_FLT) {
455 gxf_read_index(s, pkt_len);
458 if (pkt_type != PKT_MEDIA) {
459 avio_skip(pb, pkt_len);
463 av_log(s, AV_LOG_ERROR, "invalid media packet length\n");
467 track_type = avio_r8(pb);
468 track_id = avio_r8(pb);
469 stream_index = get_sindex(s, track_id, track_type);
470 if (stream_index < 0)
472 st = s->streams[stream_index];
473 field_nr = avio_rb32(pb);
474 field_info = avio_rb32(pb);
475 avio_rb32(pb); // "timeline" field number
476 avio_r8(pb); // flags
477 avio_r8(pb); // reserved
478 if (st->codec->codec_id == AV_CODEC_ID_PCM_S24LE ||
479 st->codec->codec_id == AV_CODEC_ID_PCM_S16LE) {
480 int first = field_info >> 16;
481 int last = field_info & 0xffff; // last is exclusive
482 int bps = av_get_bits_per_sample(st->codec->codec_id)>>3;
483 if (first <= last && last*bps <= pkt_len) {
484 avio_skip(pb, first*bps);
485 skip = pkt_len - last*bps;
486 pkt_len = (last-first)*bps;
488 av_log(s, AV_LOG_ERROR, "invalid first and last sample values\n");
490 ret = av_get_packet(pb, pkt, pkt_len);
493 pkt->stream_index = stream_index;
496 //set duration manually for DV or else lavf misdetects the frame rate
497 if (st->codec->codec_id == AV_CODEC_ID_DVVIDEO)
498 pkt->duration = si->fields_per_frame;
505 static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {
508 uint64_t maxlen = 100 * 1024 * 1024;
509 AVStream *st = s->streams[0];
510 int64_t start_time = s->streams[stream_index]->start_time;
513 if (timestamp < start_time) timestamp = start_time;
514 idx = av_index_search_timestamp(st, timestamp - start_time,
515 AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
518 pos = st->index_entries[idx].pos;
519 if (idx < st->nb_index_entries - 2)
520 maxlen = st->index_entries[idx + 2].pos - pos;
521 maxlen = FFMAX(maxlen, 200 * 1024);
522 res = avio_seek(s->pb, pos, SEEK_SET);
525 found = gxf_resync_media(s, maxlen, -1, timestamp);
526 if (FFABS(found - timestamp) > 4)
531 static int64_t gxf_read_timestamp(AVFormatContext *s, int stream_index,
532 int64_t *pos, int64_t pos_limit) {
533 AVIOContext *pb = s->pb;
535 if (avio_seek(pb, *pos, SEEK_SET) < 0)
536 return AV_NOPTS_VALUE;
537 res = gxf_resync_media(s, pos_limit - *pos, -1, -1);
538 *pos = avio_tell(pb);
542 AVInputFormat ff_gxf_demuxer = {
544 .long_name = NULL_IF_CONFIG_SMALL("GXF (General eXchange Format)"),
545 .priv_data_size = sizeof(struct gxf_stream_info),
546 .read_probe = gxf_probe,
547 .read_header = gxf_header,
548 .read_packet = gxf_packet,
549 .read_seek = gxf_seek,
550 .read_timestamp = gxf_read_timestamp,