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;
136 st->codec->codec_type = CODEC_TYPE_VIDEO;
137 st->codec->codec_id = CODEC_ID_MPEG1VIDEO;
140 st->codec->codec_type = CODEC_TYPE_AUDIO;
141 st->codec->codec_id = CODEC_ID_PCM_S24LE;
142 st->codec->channels = 1;
143 st->codec->sample_rate = 48000;
144 st->codec->bit_rate = 3 * 1 * 48000 * 8;
145 st->codec->block_align = 3 * 1;
146 st->codec->bits_per_sample = 24;
149 st->codec->codec_type = CODEC_TYPE_AUDIO;
150 st->codec->codec_id = CODEC_ID_PCM_S16LE;
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->channels = 2;
161 st->codec->sample_rate = 48000;
164 st->codec->codec_type = CODEC_TYPE_UNKNOWN;
165 st->codec->codec_id = CODEC_ID_NONE;
168 return s->nb_streams - 1;
172 * \brief filters out interesting tags from material information.
173 * \param len lenght of tag section, will be adjusted to contain remaining bytes
174 * \param si struct to store collected information into
176 static void gxf_material_tags(ByteIOContext *pb, int *len, st_info_t *si) {
177 si->first_field = AV_NOPTS_VALUE;
178 si->last_field = AV_NOPTS_VALUE;
180 mat_tag_t tag = get_byte(pb);
181 int tlen = get_byte(pb);
187 uint32_t value = get_be32(pb);
188 if (tag == MAT_FIRST_FIELD)
189 si->first_field = value;
190 else if (tag == MAT_LAST_FIELD)
191 si->last_field = value;
198 * \brief convert fps tag value to AVRational fps
199 * \param fps fps value from tag
200 * \return fps as AVRational, or 0 / 0 if unknown
202 static AVRational fps_tag2avr(int32_t fps) {
203 extern const AVRational ff_frame_rate_tab[];
204 if (fps < 1 || fps > 9) fps = 9;
205 return ff_frame_rate_tab[9 - fps]; // values have opposite order
209 * \brief convert UMF attributes flags to AVRational fps
210 * \param fps fps value from flags
211 * \return fps as AVRational, or 0 / 0 if unknown
213 static AVRational fps_umf2avr(uint32_t flags) {
214 static const AVRational map[] = {{50, 1}, {60000, 1001}, {24, 1},
215 {25, 1}, {30000, 1001}};
216 int idx = av_log2((flags & 0x7c0) >> 6);
221 * \brief filters out interesting tags from track information.
222 * \param len length of tag section, will be adjusted to contain remaining bytes
223 * \param si struct to store collected information into
225 static void gxf_track_tags(ByteIOContext *pb, int *len, st_info_t *si) {
226 si->frames_per_second = (AVRational){0, 0};
227 si->fields_per_frame = 0;
229 track_tag_t tag = get_byte(pb);
230 int tlen = get_byte(pb);
236 uint32_t value = get_be32(pb);
237 if (tag == TRACK_FPS)
238 si->frames_per_second = fps_tag2avr(value);
239 else if (tag == TRACK_FPF && (value == 1 || value == 2))
240 si->fields_per_frame = value;
247 * \brief read index from FLT packet into stream 0 av_index
249 static void gxf_read_index(AVFormatContext *s, int pkt_len) {
250 ByteIOContext *pb = &s->pb;
251 AVStream *st = s->streams[0];
252 uint32_t fields_per_map = get_le32(pb);
253 uint32_t map_cnt = get_le32(pb);
256 if (map_cnt > 1000) {
257 av_log(s, AV_LOG_ERROR, "GXF: too many index entries %u (%x)\n", map_cnt, map_cnt);
260 if (pkt_len < 4 * map_cnt) {
261 av_log(s, AV_LOG_ERROR, "GXF: invalid index length\n");
262 url_fskip(pb, pkt_len);
265 pkt_len -= 4 * map_cnt;
266 av_add_index_entry(st, 0, 0, 0, 0, 0);
267 for (i = 0; i < map_cnt; i++)
268 av_add_index_entry(st, (uint64_t)get_le32(pb) * 1024,
269 i * (uint64_t)fields_per_map + 1, 0, 0, 0);
270 url_fskip(pb, pkt_len);
273 static int gxf_header(AVFormatContext *s, AVFormatParameters *ap) {
274 ByteIOContext *pb = &s->pb;
278 AVRational main_timebase = {0, 0};
281 if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) {
282 av_log(s, AV_LOG_ERROR, "GXF: map packet not found\n");
286 if (get_byte(pb) != 0x0e0 || get_byte(pb) != 0xff) {
287 av_log(s, AV_LOG_ERROR, "GXF: unknown version or invalid map preamble\n");
291 len = get_be16(pb); // length of material data section
293 av_log(s, AV_LOG_ERROR, "GXF: material data longer than map data\n");
297 gxf_material_tags(pb, &len, &si);
300 len = get_be16(pb); // length of track description
302 av_log(s, AV_LOG_ERROR, "GXF: track description longer than map data\n");
307 int track_type, track_id, track_len;
311 track_type = get_byte(pb);
312 track_id = get_byte(pb);
313 track_len = get_be16(pb);
315 gxf_track_tags(pb, &track_len, &si);
316 url_fskip(pb, track_len);
317 if (!(track_type & 0x80)) {
318 av_log(s, AV_LOG_ERROR, "GXF: invalid track type %x\n", track_type);
322 if ((track_id & 0xc0) != 0xc0) {
323 av_log(s, AV_LOG_ERROR, "GXF: invalid track id %x\n", track_id);
327 idx = get_sindex(s, track_id, track_type);
328 if (idx < 0) continue;
329 st = s->streams[idx];
330 if (!main_timebase.num || !main_timebase.den) {
331 main_timebase.num = si.frames_per_second.den;
332 main_timebase.den = si.frames_per_second.num * si.fields_per_frame;
334 st->start_time = si.first_field;
335 if (si.first_field != AV_NOPTS_VALUE && si.last_field != AV_NOPTS_VALUE)
336 st->duration = si.last_field - si.first_field;
339 av_log(s, AV_LOG_ERROR, "GXF: invalid track description length specified\n");
341 url_fskip(pb, map_len);
342 if (!parse_packet_header(pb, &pkt_type, &len)) {
343 av_log(s, AV_LOG_ERROR, "GXF: sync lost in header\n");
346 if (pkt_type == PKT_FLT) {
347 gxf_read_index(s, len);
348 if (!parse_packet_header(pb, &pkt_type, &len)) {
349 av_log(s, AV_LOG_ERROR, "GXF: sync lost in header\n");
353 if (pkt_type == PKT_UMF) {
358 fps = fps_umf2avr(get_le32(pb));
359 if (!main_timebase.num || !main_timebase.den) {
360 // this may not always be correct, but simply the best we can get
361 main_timebase.num = fps.den;
362 main_timebase.den = fps.num;
365 av_log(s, AV_LOG_INFO, "GXF: UMF packet too short\n");
367 av_log(s, AV_LOG_INFO, "GXF: UMF packet missing\n");
369 for (i = 0; i < s->nb_streams; i++) {
370 AVStream *st = s->streams[i];
371 if (main_timebase.num && main_timebase.den)
372 st->time_base = main_timebase;
374 st->start_time = st->duration = AV_NOPTS_VALUE;
382 if (!max_interval-- || url_feof(pb)) \
384 tmp = tmp << 8 | get_byte(pb); \
388 * \brief resync the stream on the next media packet with specified properties
389 * \param max_interval how many bytes to search for matching packet at most
390 * \param track track id the media packet must belong to, -1 for any
391 * \param timestamp minimum timestamp (== field number) the packet must have, -1 for any
392 * \return timestamp of packet found
394 static int64_t gxf_resync_media(AVFormatContext *s, uint64_t max_interval, int track, int timestamp) {
397 uint64_t last_found_pos = 0;
399 int64_t cur_timestamp = AV_NOPTS_VALUE;
401 ByteIOContext *pb = &s->pb;
410 last_pos = url_ftell(pb);
411 url_fseek(pb, -5, SEEK_CUR);
412 if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) {
413 url_fseek(pb, last_pos, SEEK_SET);
417 cur_track = get_byte(pb);
418 cur_timestamp = get_be32(pb);
419 last_found_pos = url_ftell(pb) - 16 - 6;
420 if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) {
421 url_fseek(pb, last_pos, SEEK_SET);
426 url_fseek(pb, last_found_pos, SEEK_SET);
427 return cur_timestamp;
430 static int gxf_packet(AVFormatContext *s, AVPacket *pkt) {
431 ByteIOContext *pb = &s->pb;
434 while (!url_feof(pb)) {
435 int track_type, track_id, ret;
437 if (!parse_packet_header(pb, &pkt_type, &pkt_len)) {
439 av_log(s, AV_LOG_ERROR, "GXF: sync lost\n");
442 if (pkt_type == PKT_FLT) {
443 gxf_read_index(s, pkt_len);
446 if (pkt_type != PKT_MEDIA) {
447 url_fskip(pb, pkt_len);
451 av_log(s, AV_LOG_ERROR, "GXF: invalid media packet length\n");
455 track_type = get_byte(pb);
456 track_id = get_byte(pb);
457 field_nr = get_be32(pb);
458 get_be32(pb); // field information
459 get_be32(pb); // "timeline" field number
460 get_byte(pb); // flags
461 get_byte(pb); // reserved
462 // NOTE: there is also data length information in the
463 // field information, it might be better to take this into account
465 ret = av_get_packet(pb, pkt, pkt_len);
466 pkt->stream_index = get_sindex(s, track_id, track_type);
473 static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {
475 uint64_t maxlen = 100 * 1024 * 1024;
476 AVStream *st = s->streams[0];
477 int64_t start_time = s->streams[stream_index]->start_time;
480 if (timestamp < start_time) timestamp = start_time;
481 idx = av_index_search_timestamp(st, timestamp - start_time,
482 AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
485 pos = st->index_entries[idx].pos;
486 if (idx < st->nb_index_entries - 2)
487 maxlen = st->index_entries[idx + 2].pos - pos;
488 maxlen = FFMAX(maxlen, 200 * 1024);
489 url_fseek(&s->pb, pos, SEEK_SET);
490 found = gxf_resync_media(s, maxlen, -1, timestamp);
491 if (ABS(found - timestamp) > 4)
496 static int64_t gxf_read_timestamp(AVFormatContext *s, int stream_index,
497 int64_t *pos, int64_t pos_limit) {
498 ByteIOContext *pb = &s->pb;
500 url_fseek(pb, *pos, SEEK_SET);
501 res = gxf_resync_media(s, pos_limit - *pos, -1, -1);
502 *pos = url_ftell(pb);
506 AVInputFormat gxf_demuxer = {