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/common.h"
27 struct gxf_stream_info {
30 AVRational frames_per_second;
31 int32_t fields_per_frame;
35 * @brief parses a packet header, extracting type and length
36 * @param pb AVIOContext to read header from
37 * @param type detected packet type is stored here
38 * @param length detected packet length, excluding header is stored here
39 * @return 0 if header not found or contains invalid data, 1 otherwise
41 static int parse_packet_header(AVIOContext *pb, GXFPktType *type, int *length) {
47 *length = avio_rb32(pb);
48 if ((*length >> 24) || *length < 16)
53 if (avio_r8(pb) != 0xe1)
55 if (avio_r8(pb) != 0xe2)
61 * @brief check if file starts with a PKT_MAP header
63 static int gxf_probe(AVProbeData *p) {
64 static const uint8_t startcode[] = {0, 0, 0, 0, 1, 0xbc}; // start with map packet
65 static const uint8_t endcode[] = {0, 0, 0, 0, 0xe1, 0xe2};
66 if (!memcmp(p->buf, startcode, sizeof(startcode)) &&
67 !memcmp(&p->buf[16 - sizeof(endcode)], endcode, sizeof(endcode)))
68 return AVPROBE_SCORE_MAX;
73 * @brief gets the stream index for the track with the specified id, creates new
75 * @param id id of stream to find / add
76 * @param format stream format identifier
78 static int get_sindex(AVFormatContext *s, int id, int format) {
81 i = ff_find_stream_index(s, id);
84 st = avformat_new_stream(s, NULL);
86 return AVERROR(ENOMEM);
91 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
92 st->codec->codec_id = CODEC_ID_MJPEG;
96 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
97 st->codec->codec_id = CODEC_ID_DVVIDEO;
101 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
102 st->codec->codec_id = CODEC_ID_DVVIDEO;
107 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
108 st->codec->codec_id = CODEC_ID_MPEG2VIDEO;
109 st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
113 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
114 st->codec->codec_id = CODEC_ID_MPEG1VIDEO;
115 st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
118 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
119 st->codec->codec_id = CODEC_ID_PCM_S24LE;
120 st->codec->channels = 1;
121 st->codec->sample_rate = 48000;
122 st->codec->bit_rate = 3 * 1 * 48000 * 8;
123 st->codec->block_align = 3 * 1;
124 st->codec->bits_per_coded_sample = 24;
127 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
128 st->codec->codec_id = CODEC_ID_PCM_S16LE;
129 st->codec->channels = 1;
130 st->codec->sample_rate = 48000;
131 st->codec->bit_rate = 2 * 1 * 48000 * 8;
132 st->codec->block_align = 2 * 1;
133 st->codec->bits_per_coded_sample = 16;
136 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
137 st->codec->codec_id = CODEC_ID_AC3;
138 st->codec->channels = 2;
139 st->codec->sample_rate = 48000;
145 st->codec->codec_type = AVMEDIA_TYPE_DATA;
146 st->codec->codec_id = CODEC_ID_NONE;
149 st->codec->codec_type = AVMEDIA_TYPE_UNKNOWN;
150 st->codec->codec_id = CODEC_ID_NONE;
153 return s->nb_streams - 1;
157 * @brief filters out interesting tags from material information.
158 * @param len length of tag section, will be adjusted to contain remaining bytes
159 * @param si struct to store collected information into
161 static void gxf_material_tags(AVIOContext *pb, int *len, struct gxf_stream_info *si) {
162 si->first_field = AV_NOPTS_VALUE;
163 si->last_field = AV_NOPTS_VALUE;
165 GXFMatTag tag = avio_r8(pb);
166 int tlen = avio_r8(pb);
172 uint32_t value = avio_rb32(pb);
173 if (tag == MAT_FIRST_FIELD)
174 si->first_field = value;
175 else if (tag == MAT_LAST_FIELD)
176 si->last_field = value;
183 * @brief convert fps tag value to AVRational fps
184 * @param fps fps value from tag
185 * @return fps as AVRational, or 0 / 0 if unknown
187 static AVRational fps_tag2avr(int32_t fps) {
188 extern const AVRational avpriv_frame_rate_tab[];
189 if (fps < 1 || fps > 9) fps = 9;
190 return avpriv_frame_rate_tab[9 - fps]; // values have opposite order
194 * @brief convert UMF attributes flags to AVRational fps
195 * @param flags UMF flags to convert
196 * @return fps as AVRational, or 0 / 0 if unknown
198 static AVRational fps_umf2avr(uint32_t flags) {
199 static const AVRational map[] = {{50, 1}, {60000, 1001}, {24, 1},
200 {25, 1}, {30000, 1001}};
201 int idx = av_log2((flags & 0x7c0) >> 6);
206 * @brief filters out interesting tags from track information.
207 * @param len length of tag section, will be adjusted to contain remaining bytes
208 * @param si struct to store collected information into
210 static void gxf_track_tags(AVIOContext *pb, int *len, struct gxf_stream_info *si) {
211 si->frames_per_second = (AVRational){0, 0};
212 si->fields_per_frame = 0;
214 GXFTrackTag tag = avio_r8(pb);
215 int tlen = avio_r8(pb);
221 uint32_t value = avio_rb32(pb);
222 if (tag == TRACK_FPS)
223 si->frames_per_second = fps_tag2avr(value);
224 else if (tag == TRACK_FPF && (value == 1 || value == 2))
225 si->fields_per_frame = value;
232 * @brief read index from FLT packet into stream 0 av_index
234 static void gxf_read_index(AVFormatContext *s, int pkt_len) {
235 AVIOContext *pb = s->pb;
236 AVStream *st = s->streams[0];
237 uint32_t fields_per_map = avio_rl32(pb);
238 uint32_t map_cnt = avio_rl32(pb);
241 if (s->flags & AVFMT_FLAG_IGNIDX) {
242 avio_skip(pb, pkt_len);
245 if (map_cnt > 1000) {
246 av_log(s, AV_LOG_ERROR, "too many index entries %u (%x)\n", map_cnt, map_cnt);
249 if (pkt_len < 4 * map_cnt) {
250 av_log(s, AV_LOG_ERROR, "invalid index length\n");
251 avio_skip(pb, pkt_len);
254 pkt_len -= 4 * map_cnt;
255 av_add_index_entry(st, 0, 0, 0, 0, 0);
256 for (i = 0; i < map_cnt; i++)
257 av_add_index_entry(st, (uint64_t)avio_rl32(pb) * 1024,
258 i * (uint64_t)fields_per_map + 1, 0, 0, 0);
259 avio_skip(pb, pkt_len);
262 static int gxf_header(AVFormatContext *s, AVFormatParameters *ap) {
263 AVIOContext *pb = s->pb;
267 AVRational main_timebase = {0, 0};
268 struct gxf_stream_info *si = s->priv_data;
270 if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) {
271 av_log(s, AV_LOG_ERROR, "map packet not found\n");
275 if (avio_r8(pb) != 0x0e0 || avio_r8(pb) != 0xff) {
276 av_log(s, AV_LOG_ERROR, "unknown version or invalid map preamble\n");
280 len = avio_rb16(pb); // length of material data section
282 av_log(s, AV_LOG_ERROR, "material data longer than map data\n");
286 gxf_material_tags(pb, &len, si);
289 len = avio_rb16(pb); // length of track description
291 av_log(s, AV_LOG_ERROR, "track description longer than map data\n");
296 int track_type, track_id, track_len;
300 track_type = avio_r8(pb);
301 track_id = avio_r8(pb);
302 track_len = avio_rb16(pb);
304 gxf_track_tags(pb, &track_len, si);
305 avio_skip(pb, track_len);
306 if (!(track_type & 0x80)) {
307 av_log(s, AV_LOG_ERROR, "invalid track type %x\n", track_type);
311 if ((track_id & 0xc0) != 0xc0) {
312 av_log(s, AV_LOG_ERROR, "invalid track id %x\n", track_id);
316 idx = get_sindex(s, track_id, track_type);
317 if (idx < 0) continue;
318 st = s->streams[idx];
319 if (!main_timebase.num || !main_timebase.den) {
320 main_timebase.num = si->frames_per_second.den;
321 main_timebase.den = si->frames_per_second.num * 2;
323 st->start_time = si->first_field;
324 if (si->first_field != AV_NOPTS_VALUE && si->last_field != AV_NOPTS_VALUE)
325 st->duration = si->last_field - si->first_field;
328 av_log(s, AV_LOG_ERROR, "invalid track description length specified\n");
330 avio_skip(pb, map_len);
331 if (!parse_packet_header(pb, &pkt_type, &len)) {
332 av_log(s, AV_LOG_ERROR, "sync lost in header\n");
335 if (pkt_type == PKT_FLT) {
336 gxf_read_index(s, len);
337 if (!parse_packet_header(pb, &pkt_type, &len)) {
338 av_log(s, AV_LOG_ERROR, "sync lost in header\n");
342 if (pkt_type == PKT_UMF) {
346 avio_skip(pb, 5); // preamble
347 avio_skip(pb, 0x30); // payload description
348 fps = fps_umf2avr(avio_rl32(pb));
349 if (!main_timebase.num || !main_timebase.den) {
350 // this may not always be correct, but simply the best we can get
351 main_timebase.num = fps.den;
352 main_timebase.den = fps.num * 2;
355 av_log(s, AV_LOG_INFO, "UMF packet too short\n");
357 av_log(s, AV_LOG_INFO, "UMF packet missing\n");
359 // set a fallback value, 60000/1001 is specified for audio-only files
360 // so use that regardless of why we do not know the video frame rate.
361 if (!main_timebase.num || !main_timebase.den)
362 main_timebase = (AVRational){1001, 60000};
363 for (i = 0; i < s->nb_streams; i++) {
364 AVStream *st = s->streams[i];
365 av_set_pts_info(st, 32, main_timebase.num, main_timebase.den);
372 if (!max_interval-- || pb->eof_reached) \
374 tmp = tmp << 8 | avio_r8(pb); \
378 * @brief resync the stream on the next media packet with specified properties
379 * @param max_interval how many bytes to search for matching packet at most
380 * @param track track id the media packet must belong to, -1 for any
381 * @param timestamp minimum timestamp (== field number) the packet must have, -1 for any
382 * @return timestamp of packet found
384 static int64_t gxf_resync_media(AVFormatContext *s, uint64_t max_interval, int track, int timestamp) {
387 uint64_t last_found_pos = 0;
389 int64_t cur_timestamp = AV_NOPTS_VALUE;
391 AVIOContext *pb = s->pb;
400 last_pos = avio_tell(pb);
401 if (avio_seek(pb, -5, SEEK_CUR) < 0)
403 if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) {
404 if (avio_seek(pb, last_pos, SEEK_SET) < 0)
409 cur_track = avio_r8(pb);
410 cur_timestamp = avio_rb32(pb);
411 last_found_pos = avio_tell(pb) - 16 - 6;
412 if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) {
413 if (avio_seek(pb, last_pos, SEEK_SET) >= 0)
418 avio_seek(pb, last_found_pos, SEEK_SET);
419 return cur_timestamp;
422 static int gxf_packet(AVFormatContext *s, AVPacket *pkt) {
423 AVIOContext *pb = s->pb;
426 struct gxf_stream_info *si = s->priv_data;
428 while (!pb->eof_reached) {
430 int track_type, track_id, ret;
431 int field_nr, field_info, skip = 0;
433 if (!parse_packet_header(pb, &pkt_type, &pkt_len)) {
434 if (!pb->eof_reached)
435 av_log(s, AV_LOG_ERROR, "sync lost\n");
438 if (pkt_type == PKT_FLT) {
439 gxf_read_index(s, pkt_len);
442 if (pkt_type != PKT_MEDIA) {
443 avio_skip(pb, pkt_len);
447 av_log(s, AV_LOG_ERROR, "invalid media packet length\n");
451 track_type = avio_r8(pb);
452 track_id = avio_r8(pb);
453 stream_index = get_sindex(s, track_id, track_type);
454 if (stream_index < 0)
456 st = s->streams[stream_index];
457 field_nr = avio_rb32(pb);
458 field_info = avio_rb32(pb);
459 avio_rb32(pb); // "timeline" field number
460 avio_r8(pb); // flags
461 avio_r8(pb); // reserved
462 if (st->codec->codec_id == CODEC_ID_PCM_S24LE ||
463 st->codec->codec_id == CODEC_ID_PCM_S16LE) {
464 int first = field_info >> 16;
465 int last = field_info & 0xffff; // last is exclusive
466 int bps = av_get_bits_per_sample(st->codec->codec_id)>>3;
467 if (first <= last && last*bps <= pkt_len) {
468 avio_skip(pb, first*bps);
469 skip = pkt_len - last*bps;
470 pkt_len = (last-first)*bps;
472 av_log(s, AV_LOG_ERROR, "invalid first and last sample values\n");
474 ret = av_get_packet(pb, pkt, pkt_len);
477 pkt->stream_index = stream_index;
480 //set duration manually for DV or else lavf misdetects the frame rate
481 if (st->codec->codec_id == CODEC_ID_DVVIDEO)
482 pkt->duration = si->fields_per_frame;
489 static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {
492 uint64_t maxlen = 100 * 1024 * 1024;
493 AVStream *st = s->streams[0];
494 int64_t start_time = s->streams[stream_index]->start_time;
497 if (timestamp < start_time) timestamp = start_time;
498 idx = av_index_search_timestamp(st, timestamp - start_time,
499 AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
502 pos = st->index_entries[idx].pos;
503 if (idx < st->nb_index_entries - 2)
504 maxlen = st->index_entries[idx + 2].pos - pos;
505 maxlen = FFMAX(maxlen, 200 * 1024);
506 res = avio_seek(s->pb, pos, SEEK_SET);
509 found = gxf_resync_media(s, maxlen, -1, timestamp);
510 if (FFABS(found - timestamp) > 4)
515 static int64_t gxf_read_timestamp(AVFormatContext *s, int stream_index,
516 int64_t *pos, int64_t pos_limit) {
517 AVIOContext *pb = s->pb;
519 if (avio_seek(pb, *pos, SEEK_SET) < 0)
520 return AV_NOPTS_VALUE;
521 res = gxf_resync_media(s, pos_limit - *pos, -1, -1);
522 *pos = avio_tell(pb);
526 AVInputFormat ff_gxf_demuxer = {
528 .long_name = NULL_IF_CONFIG_SMALL("GXF format"),
529 .priv_data_size = sizeof(struct gxf_stream_info),
530 .read_probe = gxf_probe,
531 .read_header = gxf_header,
532 .read_packet = gxf_packet,
533 .read_seek = gxf_seek,
534 .read_timestamp = gxf_read_timestamp,