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->codec_tag = 0x1;
141 st->codec->channels = 1;
142 st->codec->sample_rate = 48000;
143 st->codec->bit_rate = 3 * 1 * 48000 * 8;
144 st->codec->block_align = 3 * 1;
145 st->codec->bits_per_sample = 24;
148 st->codec->codec_type = CODEC_TYPE_AUDIO;
149 st->codec->codec_id = CODEC_ID_PCM_S16LE;
150 st->codec->codec_tag = 0x1;
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_sample = 16;
158 st->codec->codec_type = CODEC_TYPE_AUDIO;
159 st->codec->codec_id = CODEC_ID_AC3;
160 st->codec->codec_tag = 0x2000;
161 st->codec->channels = 2;
162 st->codec->sample_rate = 48000;
165 st->codec->codec_type = CODEC_TYPE_UNKNOWN;
166 st->codec->codec_id = CODEC_ID_NONE;
169 return s->nb_streams - 1;
173 * \brief filters out interesting tags from material information.
174 * \param len lenght of tag section, will be adjusted to contain remaining bytes
175 * \param si struct to store collected information into
177 static void gxf_material_tags(ByteIOContext *pb, int *len, st_info_t *si) {
178 si->first_field = AV_NOPTS_VALUE;
179 si->last_field = AV_NOPTS_VALUE;
181 mat_tag_t tag = get_byte(pb);
182 int tlen = get_byte(pb);
188 uint32_t value = get_be32(pb);
189 if (tag == MAT_FIRST_FIELD)
190 si->first_field = value;
191 else if (tag == MAT_LAST_FIELD)
192 si->last_field = value;
199 * \brief convert fps tag value to AVRational fps
200 * \param fps fps value from tag
201 * \return fps as AVRational, or 0 / 0 if unknown
203 static AVRational fps_tag2avr(int32_t fps) {
204 extern const AVRational ff_frame_rate_tab[];
205 if (fps < 1 || fps > 9) fps = 9;
206 return ff_frame_rate_tab[9 - fps]; // values have opposite order
210 * \brief convert UMF attributes flags to AVRational fps
211 * \param fps fps value from flags
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(ByteIOContext *pb, int *len, st_info_t *si) {
227 si->frames_per_second = (AVRational){0, 0};
228 si->fields_per_frame = 0;
230 track_tag_t tag = get_byte(pb);
231 int tlen = get_byte(pb);
237 uint32_t value = get_be32(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 ByteIOContext *pb = &s->pb;
252 AVStream *st = s->streams[0];
253 uint32_t fields_per_map = get_le32(pb);
254 uint32_t map_cnt = get_le32(pb);
257 if (map_cnt > 1000) {
258 av_log(s, AV_LOG_ERROR, "GXF: too many index entries %u (%x)\n", map_cnt, map_cnt);
261 if (pkt_len < 4 * map_cnt) {
262 av_log(s, AV_LOG_ERROR, "GXF: invalid index length\n");
263 url_fskip(pb, pkt_len);
266 pkt_len -= 4 * map_cnt;
267 av_add_index_entry(st, 0, 0, 0, 0, 0);
268 for (i = 0; i < map_cnt; i++)
269 av_add_index_entry(st, (uint64_t)get_le32(pb) * 1024,
270 i * (uint64_t)fields_per_map + 1, 0, 0, 0);
271 url_fskip(pb, pkt_len);
274 static int gxf_header(AVFormatContext *s, AVFormatParameters *ap) {
275 ByteIOContext *pb = &s->pb;
279 AVRational main_timebase = {0, 0};
282 if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) {
283 av_log(s, AV_LOG_ERROR, "GXF: map packet not found\n");
287 if (get_byte(pb) != 0x0e0 || get_byte(pb) != 0xff) {
288 av_log(s, AV_LOG_ERROR, "GXF: unknown version or invalid map preamble\n");
292 len = get_be16(pb); // length of material data section
294 av_log(s, AV_LOG_ERROR, "GXF: material data longer than map data\n");
298 gxf_material_tags(pb, &len, &si);
301 len = get_be16(pb); // length of track description
303 av_log(s, AV_LOG_ERROR, "GXF: track description longer than map data\n");
308 int track_type, track_id, track_len;
312 track_type = get_byte(pb);
313 track_id = get_byte(pb);
314 track_len = get_be16(pb);
316 gxf_track_tags(pb, &track_len, &si);
317 url_fskip(pb, track_len);
318 if (!(track_type & 0x80)) {
319 av_log(s, AV_LOG_ERROR, "GXF: invalid track type %x\n", track_type);
323 if ((track_id & 0xc0) != 0xc0) {
324 av_log(s, AV_LOG_ERROR, "GXF: invalid track id %x\n", track_id);
328 idx = get_sindex(s, track_id, track_type);
329 if (idx < 0) continue;
330 st = s->streams[idx];
331 if (!main_timebase.num || !main_timebase.den) {
332 main_timebase.num = si.frames_per_second.den;
333 main_timebase.den = si.frames_per_second.num * si.fields_per_frame;
335 st->start_time = si.first_field;
336 if (si.first_field != AV_NOPTS_VALUE && si.last_field != AV_NOPTS_VALUE)
337 st->duration = si.last_field - si.first_field;
340 av_log(s, AV_LOG_ERROR, "GXF: invalid track description length specified\n");
342 url_fskip(pb, map_len);
343 if (!parse_packet_header(pb, &pkt_type, &len)) {
344 av_log(s, AV_LOG_ERROR, "GXF: sync lost in header\n");
347 if (pkt_type == PKT_FLT) {
348 gxf_read_index(s, len);
349 if (!parse_packet_header(pb, &pkt_type, &len)) {
350 av_log(s, AV_LOG_ERROR, "GXF: sync lost in header\n");
354 if (pkt_type == PKT_UMF) {
359 fps = fps_umf2avr(get_le32(pb));
360 if (!main_timebase.num || !main_timebase.den) {
361 // this may not always be correct, but simply the best we can get
362 main_timebase.num = fps.den;
363 main_timebase.den = fps.num;
366 av_log(s, AV_LOG_INFO, "GXF: UMF packet too short\n");
368 av_log(s, AV_LOG_INFO, "GXF: UMF packet missing\n");
370 for (i = 0; i < s->nb_streams; i++) {
371 AVStream *st = s->streams[i];
372 if (main_timebase.num && main_timebase.den)
373 st->time_base = main_timebase;
375 st->start_time = st->duration = AV_NOPTS_VALUE;
383 if (!max_interval-- || url_feof(pb)) \
385 tmp = tmp << 8 | get_byte(pb); \
389 * \brief resync the stream on the next media packet with specified properties
390 * \param max_interval how many bytes to search for matching packet at most
391 * \param track track id the media packet must belong to, -1 for any
392 * \param timestamp minimum timestamp (== field number) the packet must have, -1 for any
393 * \return timestamp of packet found
395 static int64_t gxf_resync_media(AVFormatContext *s, uint64_t max_interval, int track, int timestamp) {
398 uint64_t last_found_pos = 0;
400 int64_t cur_timestamp = AV_NOPTS_VALUE;
402 ByteIOContext *pb = &s->pb;
411 last_pos = url_ftell(pb);
412 url_fseek(pb, -5, SEEK_CUR);
413 if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) {
414 url_fseek(pb, last_pos, SEEK_SET);
418 cur_track = get_byte(pb);
419 cur_timestamp = get_be32(pb);
420 last_found_pos = url_ftell(pb) - 16 - 6;
421 if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) {
422 url_fseek(pb, last_pos, SEEK_SET);
427 url_fseek(pb, last_found_pos, SEEK_SET);
428 return cur_timestamp;
431 static int gxf_packet(AVFormatContext *s, AVPacket *pkt) {
432 ByteIOContext *pb = &s->pb;
435 while (!url_feof(pb)) {
436 int track_type, track_id, ret;
438 if (!parse_packet_header(pb, &pkt_type, &pkt_len)) {
440 av_log(s, AV_LOG_ERROR, "GXF: sync lost\n");
443 if (pkt_type == PKT_FLT) {
444 gxf_read_index(s, pkt_len);
447 if (pkt_type != PKT_MEDIA) {
448 url_fskip(pb, pkt_len);
452 av_log(s, AV_LOG_ERROR, "GXF: invalid media packet length\n");
456 track_type = get_byte(pb);
457 track_id = get_byte(pb);
458 field_nr = get_be32(pb);
459 get_be32(pb); // field information
460 get_be32(pb); // "timeline" field number
461 get_byte(pb); // flags
462 get_byte(pb); // reserved
463 // NOTE: there is also data length information in the
464 // field information, it might be better to take this into account
466 ret = av_get_packet(pb, pkt, pkt_len);
467 pkt->stream_index = get_sindex(s, track_id, track_type);
474 static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {
476 uint64_t maxlen = 100 * 1024 * 1024;
477 AVStream *st = s->streams[0];
478 int64_t start_time = s->streams[stream_index]->start_time;
481 if (timestamp < start_time) timestamp = start_time;
482 idx = av_index_search_timestamp(st, timestamp - start_time,
483 AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
486 pos = st->index_entries[idx].pos;
487 if (idx < st->nb_index_entries - 2)
488 maxlen = st->index_entries[idx + 2].pos - pos;
489 maxlen = FFMAX(maxlen, 200 * 1024);
490 url_fseek(&s->pb, pos, SEEK_SET);
491 found = gxf_resync_media(s, maxlen, -1, timestamp);
492 if (ABS(found - timestamp) > 4)
497 static int64_t gxf_read_timestamp(AVFormatContext *s, int stream_index,
498 int64_t *pos, int64_t pos_limit) {
499 ByteIOContext *pb = &s->pb;
501 url_fseek(pb, *pos, SEEK_SET);
502 res = gxf_resync_media(s, pos_limit - *pos, -1, -1);
503 *pos = url_ftell(pb);
507 AVInputFormat gxf_demuxer = {