3 * Copyright (c) 2006 Reimar Doeffinger.
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
32 MAT_FIRST_FIELD = 0x41,
33 MAT_LAST_FIELD = 0x42,
52 AVRational frames_per_second;
53 int32_t fields_per_frame;
57 * \brief parses a packet header, extracting type and length
58 * \param pb ByteIOContext 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(ByteIOContext *pb, pkt_type_t *type, int *length) {
66 if (get_byte(pb) != 1)
69 *length = get_be32(pb);
70 if ((*length >> 24) || *length < 16)
75 if (get_byte(pb) != 0xe1)
77 if (get_byte(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};
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 stream id of stream to find / add
100 * \param format stream format identifier
102 static int get_sindex(AVFormatContext *s, int id, int format) {
105 for (i = 0; i < s->nb_streams; i++) {
106 if (s->streams[i]->id == id)
109 st = av_new_stream(s, id);
113 st->codec->codec_type = CODEC_TYPE_VIDEO;
114 st->codec->codec_id = CODEC_ID_MJPEG;
118 st->codec->codec_type = CODEC_TYPE_VIDEO;
119 st->codec->codec_id = CODEC_ID_DVVIDEO;
123 st->codec->codec_type = CODEC_TYPE_VIDEO;
124 st->codec->codec_id = CODEC_ID_DVVIDEO;
129 st->codec->codec_type = CODEC_TYPE_VIDEO;
130 st->codec->codec_id = CODEC_ID_MPEG2VIDEO;
134 st->codec->codec_type = CODEC_TYPE_VIDEO;
135 st->codec->codec_id = CODEC_ID_MPEG1VIDEO;
138 st->codec->codec_type = CODEC_TYPE_AUDIO;
139 st->codec->codec_id = CODEC_ID_PCM_S24LE;
140 st->codec->channels = 1;
141 st->codec->sample_rate = 48000;
142 st->codec->bit_rate = 3 * 1 * 48000 * 8;
143 st->codec->block_align = 3 * 1;
144 st->codec->bits_per_sample = 24;
147 st->codec->codec_type = CODEC_TYPE_AUDIO;
148 st->codec->codec_id = CODEC_ID_PCM_S16LE;
149 st->codec->channels = 1;
150 st->codec->sample_rate = 48000;
151 st->codec->bit_rate = 2 * 1 * 48000 * 8;
152 st->codec->block_align = 2 * 1;
153 st->codec->bits_per_sample = 16;
156 st->codec->codec_type = CODEC_TYPE_AUDIO;
157 st->codec->codec_id = CODEC_ID_AC3;
158 st->codec->channels = 2;
159 st->codec->sample_rate = 48000;
162 st->codec->codec_type = CODEC_TYPE_UNKNOWN;
163 st->codec->codec_id = CODEC_ID_NONE;
166 return s->nb_streams - 1;
170 * \brief filters out interesting tags from material information.
171 * \param len lenght of tag section, will be adjusted to contain remaining bytes
172 * \param si struct to store collected information into
174 static void gxf_material_tags(ByteIOContext *pb, int *len, st_info_t *si) {
175 si->first_field = AV_NOPTS_VALUE;
176 si->last_field = AV_NOPTS_VALUE;
178 mat_tag_t tag = get_byte(pb);
179 int tlen = get_byte(pb);
185 uint32_t value = get_be32(pb);
186 if (tag == MAT_FIRST_FIELD)
187 si->first_field = value;
188 else if (tag == MAT_LAST_FIELD)
189 si->last_field = value;
196 * \brief convert fps tag value to AVRational fps
197 * \param fps fps value from tag
198 * \return fps as AVRational, or 0 / 0 if unknown
200 static AVRational fps_tag2avr(int32_t fps) {
201 extern const AVRational ff_frame_rate_tab[];
202 if (fps < 1 || fps > 9) fps = 9;
203 return ff_frame_rate_tab[9 - fps]; // values have opposite order
207 * \brief convert UMF attributes flags to AVRational fps
208 * \param fps fps value from flags
209 * \return fps as AVRational, or 0 / 0 if unknown
211 static AVRational fps_umf2avr(uint32_t flags) {
212 static const AVRational map[] = {{50, 1}, {60000, 1001}, {24, 1},
213 {25, 1}, {30000, 1001}};
214 int idx = av_log2((flags & 0x7c0) >> 6);
219 * \brief filters out interesting tags from track information.
220 * \param len length of tag section, will be adjusted to contain remaining bytes
221 * \param si struct to store collected information into
223 static void gxf_track_tags(ByteIOContext *pb, int *len, st_info_t *si) {
224 si->frames_per_second = (AVRational){0, 0};
225 si->fields_per_frame = 0;
227 track_tag_t tag = get_byte(pb);
228 int tlen = get_byte(pb);
234 uint32_t value = get_be32(pb);
235 if (tag == TRACK_FPS)
236 si->frames_per_second = fps_tag2avr(value);
237 else if (tag == TRACK_FPF && (value == 1 || value == 2))
238 si->fields_per_frame = value;
245 * \brief read index from FLT packet into stream 0 av_index
247 static void gxf_read_index(AVFormatContext *s, int pkt_len) {
248 ByteIOContext *pb = &s->pb;
249 AVStream *st = s->streams[0];
250 uint32_t fields_per_map = get_le32(pb);
251 uint32_t map_cnt = get_le32(pb);
254 if (map_cnt > 1000) {
255 av_log(s, AV_LOG_ERROR, "GXF: too many index entries %u (%x)\n", map_cnt, map_cnt);
258 if (pkt_len < 4 * map_cnt) {
259 av_log(s, AV_LOG_ERROR, "GXF: invalid index length\n");
260 url_fskip(pb, pkt_len);
263 pkt_len -= 4 * map_cnt;
264 av_add_index_entry(st, 0, 0, 0, 0, 0);
265 for (i = 0; i < map_cnt; i++)
266 av_add_index_entry(st, (uint64_t)get_le32(pb) * 1024,
267 i * (uint64_t)fields_per_map + 1, 0, 0, 0);
268 url_fskip(pb, pkt_len);
271 static int gxf_header(AVFormatContext *s, AVFormatParameters *ap) {
272 ByteIOContext *pb = &s->pb;
276 AVRational main_timebase = {0, 0};
279 if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) {
280 av_log(s, AV_LOG_ERROR, "GXF: map packet not found\n");
284 if (get_byte(pb) != 0x0e0 || get_byte(pb) != 0xff) {
285 av_log(s, AV_LOG_ERROR, "GXF: unknown version or invalid map preamble\n");
289 len = get_be16(pb); // length of material data section
291 av_log(s, AV_LOG_ERROR, "GXF: material data longer than map data\n");
295 gxf_material_tags(pb, &len, &si);
298 len = get_be16(pb); // length of track description
300 av_log(s, AV_LOG_ERROR, "GXF: track description longer than map data\n");
305 int track_type, track_id, track_len;
309 track_type = get_byte(pb);
310 track_id = get_byte(pb);
311 track_len = get_be16(pb);
313 gxf_track_tags(pb, &track_len, &si);
314 url_fskip(pb, track_len);
315 if (!(track_type & 0x80)) {
316 av_log(s, AV_LOG_ERROR, "GXF: invalid track type %x\n", track_type);
320 if ((track_id & 0xc0) != 0xc0) {
321 av_log(s, AV_LOG_ERROR, "GXF: invalid track id %x\n", track_id);
325 idx = get_sindex(s, track_id, track_type);
326 if (idx < 0) continue;
327 st = s->streams[idx];
328 if (!main_timebase.num || !main_timebase.den) {
329 main_timebase.num = si.frames_per_second.den;
330 main_timebase.den = si.frames_per_second.num * si.fields_per_frame;
332 st->start_time = si.first_field;
333 if (si.first_field != AV_NOPTS_VALUE && si.last_field != AV_NOPTS_VALUE)
334 st->duration = si.last_field - si.first_field;
337 av_log(s, AV_LOG_ERROR, "GXF: invalid track description length specified\n");
339 url_fskip(pb, map_len);
340 if (!parse_packet_header(pb, &pkt_type, &len)) {
341 av_log(s, AV_LOG_ERROR, "GXF: sync lost in header\n");
344 if (pkt_type == PKT_FLT) {
345 gxf_read_index(s, len);
346 if (!parse_packet_header(pb, &pkt_type, &len)) {
347 av_log(s, AV_LOG_ERROR, "GXF: sync lost in header\n");
351 if (pkt_type == PKT_UMF) {
356 fps = fps_umf2avr(get_le32(pb));
357 if (!main_timebase.num || !main_timebase.den) {
358 // this may not always be correct, but simply the best we can get
359 main_timebase.num = fps.den;
360 main_timebase.den = fps.num;
363 av_log(s, AV_LOG_INFO, "GXF: UMF packet too short\n");
365 av_log(s, AV_LOG_INFO, "GXF: UMF packet missing\n");
367 for (i = 0; i < s->nb_streams; i++) {
368 AVStream *st = s->streams[i];
369 if (main_timebase.num && main_timebase.den)
370 st->time_base = main_timebase;
372 st->start_time = st->duration = AV_NOPTS_VALUE;
380 if (!max_interval-- || url_feof(pb)) \
382 tmp = tmp << 8 | get_byte(pb); \
386 * \brief resync the stream on the next media packet with specified properties
387 * \param max_interval how many bytes to search for matching packet at most
388 * \param track track id the media packet must belong to, -1 for any
389 * \param timestamp minimum timestamp (== field number) the packet must have, -1 for any
390 * \return timestamp of packet found
392 static int64_t gxf_resync_media(AVFormatContext *s, uint64_t max_interval, int track, int timestamp) {
395 uint64_t last_found_pos = 0;
397 int64_t cur_timestamp = AV_NOPTS_VALUE;
399 ByteIOContext *pb = &s->pb;
408 last_pos = url_ftell(pb);
409 url_fseek(pb, -5, SEEK_CUR);
410 if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) {
411 url_fseek(pb, last_pos, SEEK_SET);
415 cur_track = get_byte(pb);
416 cur_timestamp = get_be32(pb);
417 last_found_pos = url_ftell(pb) - 16 - 6;
418 if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) {
419 url_fseek(pb, last_pos, SEEK_SET);
424 url_fseek(pb, last_found_pos, SEEK_SET);
425 return cur_timestamp;
428 static int gxf_packet(AVFormatContext *s, AVPacket *pkt) {
429 ByteIOContext *pb = &s->pb;
432 while (!url_feof(pb)) {
433 int track_type, track_id, ret;
435 if (!parse_packet_header(pb, &pkt_type, &pkt_len)) {
437 av_log(s, AV_LOG_ERROR, "GXF: sync lost\n");
440 if (pkt_type == PKT_FLT) {
441 gxf_read_index(s, pkt_len);
444 if (pkt_type != PKT_MEDIA) {
445 url_fskip(pb, pkt_len);
449 av_log(s, AV_LOG_ERROR, "GXF: invalid media packet length\n");
453 track_type = get_byte(pb);
454 track_id = get_byte(pb);
455 field_nr = get_be32(pb);
456 get_be32(pb); // field information
457 get_be32(pb); // "timeline" field number
458 get_byte(pb); // flags
459 get_byte(pb); // reserved
460 // NOTE: there is also data length information in the
461 // field information, it might be better to take this into account
463 ret = av_get_packet(pb, pkt, pkt_len);
464 pkt->stream_index = get_sindex(s, track_id, track_type);
471 static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {
473 uint64_t maxlen = 100 * 1024 * 1024;
474 AVStream *st = s->streams[0];
475 int64_t start_time = s->streams[stream_index]->start_time;
478 if (timestamp < start_time) timestamp = start_time;
479 idx = av_index_search_timestamp(st, timestamp - start_time,
480 AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
483 pos = st->index_entries[idx].pos;
484 if (idx < st->nb_index_entries - 2)
485 maxlen = st->index_entries[idx + 2].pos - pos;
486 maxlen = FFMAX(maxlen, 200 * 1024);
487 url_fseek(&s->pb, pos, SEEK_SET);
488 found = gxf_resync_media(s, maxlen, -1, timestamp);
489 if (ABS(found - timestamp) > 4)
494 static int64_t gxf_read_timestamp(AVFormatContext *s, int stream_index,
495 int64_t *pos, int64_t pos_limit) {
496 ByteIOContext *pb = &s->pb;
498 url_fseek(pb, *pos, SEEK_SET);
499 res = gxf_resync_media(s, pos_limit - *pos, -1, -1);
500 *pos = url_ftell(pb);
504 AVInputFormat gxf_demuxer = {