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
34 MAT_FIRST_FIELD = 0x41,
35 MAT_LAST_FIELD = 0x42,
54 AVRational frames_per_second;
55 int32_t fields_per_frame;
59 * \brief parses a packet header, extracting type and length
60 * \param pb ByteIOContext 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(ByteIOContext *pb, pkt_type_t *type, int *length) {
68 if (get_byte(pb) != 1)
71 *length = get_be32(pb);
72 if ((*length >> 24) || *length < 16)
77 if (get_byte(pb) != 0xe1)
79 if (get_byte(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};
92 if (!memcmp(p->buf, startcode, sizeof(startcode)) &&
93 !memcmp(&p->buf[16 - sizeof(endcode)], endcode, sizeof(endcode)))
94 return AVPROBE_SCORE_MAX;
99 * \brief gets the stream index for the track with the specified id, creates new
100 * stream if not found
101 * \param stream id of stream to find / add
102 * \param format stream format identifier
104 static int get_sindex(AVFormatContext *s, int id, int format) {
107 for (i = 0; i < s->nb_streams; i++) {
108 if (s->streams[i]->id == id)
111 st = av_new_stream(s, id);
115 st->codec->codec_type = CODEC_TYPE_VIDEO;
116 st->codec->codec_id = CODEC_ID_MJPEG;
120 st->codec->codec_type = CODEC_TYPE_VIDEO;
121 st->codec->codec_id = CODEC_ID_DVVIDEO;
125 st->codec->codec_type = CODEC_TYPE_VIDEO;
126 st->codec->codec_id = CODEC_ID_DVVIDEO;
131 st->codec->codec_type = CODEC_TYPE_VIDEO;
132 st->codec->codec_id = CODEC_ID_MPEG2VIDEO;
133 st->need_parsing = 2; // get keyframe flag etc.
137 st->codec->codec_type = CODEC_TYPE_VIDEO;
138 st->codec->codec_id = CODEC_ID_MPEG1VIDEO;
139 st->need_parsing = 2; // get keyframe flag etc.
142 st->codec->codec_type = CODEC_TYPE_AUDIO;
143 st->codec->codec_id = CODEC_ID_PCM_S24LE;
144 st->codec->channels = 1;
145 st->codec->sample_rate = 48000;
146 st->codec->bit_rate = 3 * 1 * 48000 * 8;
147 st->codec->block_align = 3 * 1;
148 st->codec->bits_per_sample = 24;
151 st->codec->codec_type = CODEC_TYPE_AUDIO;
152 st->codec->codec_id = CODEC_ID_PCM_S16LE;
153 st->codec->channels = 1;
154 st->codec->sample_rate = 48000;
155 st->codec->bit_rate = 2 * 1 * 48000 * 8;
156 st->codec->block_align = 2 * 1;
157 st->codec->bits_per_sample = 16;
160 st->codec->codec_type = CODEC_TYPE_AUDIO;
161 st->codec->codec_id = CODEC_ID_AC3;
162 st->codec->channels = 2;
163 st->codec->sample_rate = 48000;
169 st->codec->codec_type = CODEC_TYPE_DATA;
170 st->codec->codec_id = CODEC_ID_NONE;
173 st->codec->codec_type = CODEC_TYPE_UNKNOWN;
174 st->codec->codec_id = CODEC_ID_NONE;
177 return s->nb_streams - 1;
181 * \brief filters out interesting tags from material information.
182 * \param len lenght of tag section, will be adjusted to contain remaining bytes
183 * \param si struct to store collected information into
185 static void gxf_material_tags(ByteIOContext *pb, int *len, st_info_t *si) {
186 si->first_field = AV_NOPTS_VALUE;
187 si->last_field = AV_NOPTS_VALUE;
189 mat_tag_t tag = get_byte(pb);
190 int tlen = get_byte(pb);
196 uint32_t value = get_be32(pb);
197 if (tag == MAT_FIRST_FIELD)
198 si->first_field = value;
199 else if (tag == MAT_LAST_FIELD)
200 si->last_field = value;
207 * \brief convert fps tag value to AVRational fps
208 * \param fps fps value from tag
209 * \return fps as AVRational, or 0 / 0 if unknown
211 static AVRational fps_tag2avr(int32_t fps) {
212 extern const AVRational ff_frame_rate_tab[];
213 if (fps < 1 || fps > 9) fps = 9;
214 return ff_frame_rate_tab[9 - fps]; // values have opposite order
218 * \brief convert UMF attributes flags to AVRational fps
219 * \param fps fps value from flags
220 * \return fps as AVRational, or 0 / 0 if unknown
222 static AVRational fps_umf2avr(uint32_t flags) {
223 static const AVRational map[] = {{50, 1}, {60000, 1001}, {24, 1},
224 {25, 1}, {30000, 1001}};
225 int idx = av_log2((flags & 0x7c0) >> 6);
230 * \brief filters out interesting tags from track information.
231 * \param len length of tag section, will be adjusted to contain remaining bytes
232 * \param si struct to store collected information into
234 static void gxf_track_tags(ByteIOContext *pb, int *len, st_info_t *si) {
235 si->frames_per_second = (AVRational){0, 0};
236 si->fields_per_frame = 0;
238 track_tag_t tag = get_byte(pb);
239 int tlen = get_byte(pb);
245 uint32_t value = get_be32(pb);
246 if (tag == TRACK_FPS)
247 si->frames_per_second = fps_tag2avr(value);
248 else if (tag == TRACK_FPF && (value == 1 || value == 2))
249 si->fields_per_frame = value;
256 * \brief read index from FLT packet into stream 0 av_index
258 static void gxf_read_index(AVFormatContext *s, int pkt_len) {
259 ByteIOContext *pb = &s->pb;
260 AVStream *st = s->streams[0];
261 uint32_t fields_per_map = get_le32(pb);
262 uint32_t map_cnt = get_le32(pb);
265 if (map_cnt > 1000) {
266 av_log(s, AV_LOG_ERROR, "GXF: too many index entries %u (%x)\n", map_cnt, map_cnt);
269 if (pkt_len < 4 * map_cnt) {
270 av_log(s, AV_LOG_ERROR, "GXF: invalid index length\n");
271 url_fskip(pb, pkt_len);
274 pkt_len -= 4 * map_cnt;
275 av_add_index_entry(st, 0, 0, 0, 0, 0);
276 for (i = 0; i < map_cnt; i++)
277 av_add_index_entry(st, (uint64_t)get_le32(pb) * 1024,
278 i * (uint64_t)fields_per_map + 1, 0, 0, 0);
279 url_fskip(pb, pkt_len);
282 static int gxf_header(AVFormatContext *s, AVFormatParameters *ap) {
283 ByteIOContext *pb = &s->pb;
287 AVRational main_timebase = {0, 0};
290 if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) {
291 av_log(s, AV_LOG_ERROR, "GXF: map packet not found\n");
295 if (get_byte(pb) != 0x0e0 || get_byte(pb) != 0xff) {
296 av_log(s, AV_LOG_ERROR, "GXF: unknown version or invalid map preamble\n");
300 len = get_be16(pb); // length of material data section
302 av_log(s, AV_LOG_ERROR, "GXF: material data longer than map data\n");
306 gxf_material_tags(pb, &len, &si);
309 len = get_be16(pb); // length of track description
311 av_log(s, AV_LOG_ERROR, "GXF: track description longer than map data\n");
316 int track_type, track_id, track_len;
320 track_type = get_byte(pb);
321 track_id = get_byte(pb);
322 track_len = get_be16(pb);
324 gxf_track_tags(pb, &track_len, &si);
325 url_fskip(pb, track_len);
326 if (!(track_type & 0x80)) {
327 av_log(s, AV_LOG_ERROR, "GXF: invalid track type %x\n", track_type);
331 if ((track_id & 0xc0) != 0xc0) {
332 av_log(s, AV_LOG_ERROR, "GXF: invalid track id %x\n", track_id);
336 idx = get_sindex(s, track_id, track_type);
337 if (idx < 0) continue;
338 st = s->streams[idx];
339 if (!main_timebase.num || !main_timebase.den) {
340 main_timebase.num = si.frames_per_second.den;
341 main_timebase.den = si.frames_per_second.num * si.fields_per_frame;
343 st->start_time = si.first_field;
344 if (si.first_field != AV_NOPTS_VALUE && si.last_field != AV_NOPTS_VALUE)
345 st->duration = si.last_field - si.first_field;
348 av_log(s, AV_LOG_ERROR, "GXF: invalid track description length specified\n");
350 url_fskip(pb, map_len);
351 if (!parse_packet_header(pb, &pkt_type, &len)) {
352 av_log(s, AV_LOG_ERROR, "GXF: sync lost in header\n");
355 if (pkt_type == PKT_FLT) {
356 gxf_read_index(s, len);
357 if (!parse_packet_header(pb, &pkt_type, &len)) {
358 av_log(s, AV_LOG_ERROR, "GXF: sync lost in header\n");
362 if (pkt_type == PKT_UMF) {
366 url_fskip(pb, 5); // preamble
367 url_fskip(pb, 0x30); // payload description
368 fps = fps_umf2avr(get_le32(pb));
369 if (!main_timebase.num || !main_timebase.den) {
370 // this may not always be correct, but simply the best we can get
371 main_timebase.num = fps.den;
372 main_timebase.den = fps.num;
375 av_log(s, AV_LOG_INFO, "GXF: UMF packet too short\n");
377 av_log(s, AV_LOG_INFO, "GXF: UMF packet missing\n");
379 if (!main_timebase.num || !main_timebase.den)
380 main_timebase = (AVRational){1, 50}; // set some arbitrary fallback
381 for (i = 0; i < s->nb_streams; i++) {
382 AVStream *st = s->streams[i];
383 av_set_pts_info(st, 32, main_timebase.num, main_timebase.den);
390 if (!max_interval-- || url_feof(pb)) \
392 tmp = tmp << 8 | get_byte(pb); \
396 * \brief resync the stream on the next media packet with specified properties
397 * \param max_interval how many bytes to search for matching packet at most
398 * \param track track id the media packet must belong to, -1 for any
399 * \param timestamp minimum timestamp (== field number) the packet must have, -1 for any
400 * \return timestamp of packet found
402 static int64_t gxf_resync_media(AVFormatContext *s, uint64_t max_interval, int track, int timestamp) {
405 uint64_t last_found_pos = 0;
407 int64_t cur_timestamp = AV_NOPTS_VALUE;
409 ByteIOContext *pb = &s->pb;
418 last_pos = url_ftell(pb);
419 url_fseek(pb, -5, SEEK_CUR);
420 if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) {
421 url_fseek(pb, last_pos, SEEK_SET);
425 cur_track = get_byte(pb);
426 cur_timestamp = get_be32(pb);
427 last_found_pos = url_ftell(pb) - 16 - 6;
428 if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) {
429 url_fseek(pb, last_pos, SEEK_SET);
434 url_fseek(pb, last_found_pos, SEEK_SET);
435 return cur_timestamp;
438 static int gxf_packet(AVFormatContext *s, AVPacket *pkt) {
439 ByteIOContext *pb = &s->pb;
442 while (!url_feof(pb)) {
443 int track_type, track_id, ret;
445 if (!parse_packet_header(pb, &pkt_type, &pkt_len)) {
447 av_log(s, AV_LOG_ERROR, "GXF: sync lost\n");
450 if (pkt_type == PKT_FLT) {
451 gxf_read_index(s, pkt_len);
454 if (pkt_type != PKT_MEDIA) {
455 url_fskip(pb, pkt_len);
459 av_log(s, AV_LOG_ERROR, "GXF: invalid media packet length\n");
463 track_type = get_byte(pb);
464 track_id = get_byte(pb);
465 field_nr = get_be32(pb);
466 get_be32(pb); // field information
467 get_be32(pb); // "timeline" field number
468 get_byte(pb); // flags
469 get_byte(pb); // reserved
470 // NOTE: there is also data length information in the
471 // field information, it might be better to take this into account
473 ret = av_get_packet(pb, pkt, pkt_len);
474 pkt->stream_index = get_sindex(s, track_id, track_type);
481 static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {
483 uint64_t maxlen = 100 * 1024 * 1024;
484 AVStream *st = s->streams[0];
485 int64_t start_time = s->streams[stream_index]->start_time;
488 if (timestamp < start_time) timestamp = start_time;
489 idx = av_index_search_timestamp(st, timestamp - start_time,
490 AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
493 pos = st->index_entries[idx].pos;
494 if (idx < st->nb_index_entries - 2)
495 maxlen = st->index_entries[idx + 2].pos - pos;
496 maxlen = FFMAX(maxlen, 200 * 1024);
497 url_fseek(&s->pb, pos, SEEK_SET);
498 found = gxf_resync_media(s, maxlen, -1, timestamp);
499 if (FFABS(found - timestamp) > 4)
504 static int64_t gxf_read_timestamp(AVFormatContext *s, int stream_index,
505 int64_t *pos, int64_t pos_limit) {
506 ByteIOContext *pb = &s->pb;
508 url_fseek(pb, *pos, SEEK_SET);
509 res = gxf_resync_media(s, pos_limit - *pos, -1, -1);
510 *pos = url_ftell(pb);
514 AVInputFormat gxf_demuxer = {