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
22 #include "libavutil/common.h"
26 struct gxf_stream_info {
29 AVRational frames_per_second;
30 int32_t fields_per_frame;
34 * \brief parses a packet header, extracting type and length
35 * \param pb ByteIOContext to read header from
36 * \param type detected packet type is stored here
37 * \param length detected packet length, excluding header is stored here
38 * \return 0 if header not found or contains invalid data, 1 otherwise
40 static int parse_packet_header(ByteIOContext *pb, GXFPktType *type, int *length) {
43 if (get_byte(pb) != 1)
46 *length = get_be32(pb);
47 if ((*length >> 24) || *length < 16)
52 if (get_byte(pb) != 0xe1)
54 if (get_byte(pb) != 0xe2)
60 * \brief check if file starts with a PKT_MAP header
62 static int gxf_probe(AVProbeData *p) {
63 static const uint8_t startcode[] = {0, 0, 0, 0, 1, 0xbc}; // start with map packet
64 static const uint8_t endcode[] = {0, 0, 0, 0, 0xe1, 0xe2};
65 if (!memcmp(p->buf, startcode, sizeof(startcode)) &&
66 !memcmp(&p->buf[16 - sizeof(endcode)], endcode, sizeof(endcode)))
67 return AVPROBE_SCORE_MAX;
72 * \brief gets the stream index for the track with the specified id, creates new
74 * \param stream id of stream to find / add
75 * \param format stream format identifier
77 static int get_sindex(AVFormatContext *s, int id, int format) {
80 for (i = 0; i < s->nb_streams; i++) {
81 if (s->streams[i]->id == id)
84 st = av_new_stream(s, id);
86 return AVERROR(ENOMEM);
90 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
91 st->codec->codec_id = CODEC_ID_MJPEG;
95 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
96 st->codec->codec_id = CODEC_ID_DVVIDEO;
100 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
101 st->codec->codec_id = CODEC_ID_DVVIDEO;
106 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
107 st->codec->codec_id = CODEC_ID_MPEG2VIDEO;
108 st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
112 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
113 st->codec->codec_id = CODEC_ID_MPEG1VIDEO;
114 st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
117 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
118 st->codec->codec_id = CODEC_ID_PCM_S24LE;
119 st->codec->channels = 1;
120 st->codec->sample_rate = 48000;
121 st->codec->bit_rate = 3 * 1 * 48000 * 8;
122 st->codec->block_align = 3 * 1;
123 st->codec->bits_per_coded_sample = 24;
126 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
127 st->codec->codec_id = CODEC_ID_PCM_S16LE;
128 st->codec->channels = 1;
129 st->codec->sample_rate = 48000;
130 st->codec->bit_rate = 2 * 1 * 48000 * 8;
131 st->codec->block_align = 2 * 1;
132 st->codec->bits_per_coded_sample = 16;
135 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
136 st->codec->codec_id = CODEC_ID_AC3;
137 st->codec->channels = 2;
138 st->codec->sample_rate = 48000;
144 st->codec->codec_type = AVMEDIA_TYPE_DATA;
145 st->codec->codec_id = CODEC_ID_NONE;
148 st->codec->codec_type = AVMEDIA_TYPE_UNKNOWN;
149 st->codec->codec_id = CODEC_ID_NONE;
152 return s->nb_streams - 1;
156 * \brief filters out interesting tags from material information.
157 * \param len length of tag section, will be adjusted to contain remaining bytes
158 * \param si struct to store collected information into
160 static void gxf_material_tags(ByteIOContext *pb, int *len, struct gxf_stream_info *si) {
161 si->first_field = AV_NOPTS_VALUE;
162 si->last_field = AV_NOPTS_VALUE;
164 GXFMatTag tag = get_byte(pb);
165 int tlen = get_byte(pb);
171 uint32_t value = get_be32(pb);
172 if (tag == MAT_FIRST_FIELD)
173 si->first_field = value;
174 else if (tag == MAT_LAST_FIELD)
175 si->last_field = value;
182 * \brief convert fps tag value to AVRational fps
183 * \param fps fps value from tag
184 * \return fps as AVRational, or 0 / 0 if unknown
186 static AVRational fps_tag2avr(int32_t fps) {
187 extern const AVRational ff_frame_rate_tab[];
188 if (fps < 1 || fps > 9) fps = 9;
189 return ff_frame_rate_tab[9 - fps]; // values have opposite order
193 * \brief convert UMF attributes flags to AVRational fps
194 * \param fps fps value from flags
195 * \return fps as AVRational, or 0 / 0 if unknown
197 static AVRational fps_umf2avr(uint32_t flags) {
198 static const AVRational map[] = {{50, 1}, {60000, 1001}, {24, 1},
199 {25, 1}, {30000, 1001}};
200 int idx = av_log2((flags & 0x7c0) >> 6);
205 * \brief filters out interesting tags from track information.
206 * \param len length of tag section, will be adjusted to contain remaining bytes
207 * \param si struct to store collected information into
209 static void gxf_track_tags(ByteIOContext *pb, int *len, struct gxf_stream_info *si) {
210 si->frames_per_second = (AVRational){0, 0};
211 si->fields_per_frame = 0;
213 GXFTrackTag tag = get_byte(pb);
214 int tlen = get_byte(pb);
220 uint32_t value = get_be32(pb);
221 if (tag == TRACK_FPS)
222 si->frames_per_second = fps_tag2avr(value);
223 else if (tag == TRACK_FPF && (value == 1 || value == 2))
224 si->fields_per_frame = value;
231 * \brief read index from FLT packet into stream 0 av_index
233 static void gxf_read_index(AVFormatContext *s, int pkt_len) {
234 ByteIOContext *pb = s->pb;
235 AVStream *st = s->streams[0];
236 uint32_t fields_per_map = get_le32(pb);
237 uint32_t map_cnt = get_le32(pb);
240 if (s->flags & AVFMT_FLAG_IGNIDX) {
241 url_fskip(pb, pkt_len);
244 if (map_cnt > 1000) {
245 av_log(s, AV_LOG_ERROR, "too many index entries %u (%x)\n", map_cnt, map_cnt);
248 if (pkt_len < 4 * map_cnt) {
249 av_log(s, AV_LOG_ERROR, "invalid index length\n");
250 url_fskip(pb, pkt_len);
253 pkt_len -= 4 * map_cnt;
254 av_add_index_entry(st, 0, 0, 0, 0, 0);
255 for (i = 0; i < map_cnt; i++)
256 av_add_index_entry(st, (uint64_t)get_le32(pb) * 1024,
257 i * (uint64_t)fields_per_map + 1, 0, 0, 0);
258 url_fskip(pb, pkt_len);
261 static int gxf_header(AVFormatContext *s, AVFormatParameters *ap) {
262 ByteIOContext *pb = s->pb;
266 AVRational main_timebase = {0, 0};
267 struct gxf_stream_info si;
269 if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) {
270 av_log(s, AV_LOG_ERROR, "map packet not found\n");
274 if (get_byte(pb) != 0x0e0 || get_byte(pb) != 0xff) {
275 av_log(s, AV_LOG_ERROR, "unknown version or invalid map preamble\n");
279 len = get_be16(pb); // length of material data section
281 av_log(s, AV_LOG_ERROR, "material data longer than map data\n");
285 gxf_material_tags(pb, &len, &si);
288 len = get_be16(pb); // length of track description
290 av_log(s, AV_LOG_ERROR, "track description longer than map data\n");
295 int track_type, track_id, track_len;
299 track_type = get_byte(pb);
300 track_id = get_byte(pb);
301 track_len = get_be16(pb);
303 gxf_track_tags(pb, &track_len, &si);
304 url_fskip(pb, track_len);
305 if (!(track_type & 0x80)) {
306 av_log(s, AV_LOG_ERROR, "invalid track type %x\n", track_type);
310 if ((track_id & 0xc0) != 0xc0) {
311 av_log(s, AV_LOG_ERROR, "invalid track id %x\n", track_id);
315 idx = get_sindex(s, track_id, track_type);
316 if (idx < 0) continue;
317 st = s->streams[idx];
318 if (!main_timebase.num || !main_timebase.den) {
319 main_timebase.num = si.frames_per_second.den;
320 main_timebase.den = si.frames_per_second.num * 2;
322 st->start_time = si.first_field;
323 if (si.first_field != AV_NOPTS_VALUE && si.last_field != AV_NOPTS_VALUE)
324 st->duration = si.last_field - si.first_field;
327 av_log(s, AV_LOG_ERROR, "invalid track description length specified\n");
329 url_fskip(pb, map_len);
330 if (!parse_packet_header(pb, &pkt_type, &len)) {
331 av_log(s, AV_LOG_ERROR, "sync lost in header\n");
334 if (pkt_type == PKT_FLT) {
335 gxf_read_index(s, len);
336 if (!parse_packet_header(pb, &pkt_type, &len)) {
337 av_log(s, AV_LOG_ERROR, "sync lost in header\n");
341 if (pkt_type == PKT_UMF) {
345 url_fskip(pb, 5); // preamble
346 url_fskip(pb, 0x30); // payload description
347 fps = fps_umf2avr(get_le32(pb));
348 if (!main_timebase.num || !main_timebase.den) {
349 // this may not always be correct, but simply the best we can get
350 main_timebase.num = fps.den;
351 main_timebase.den = fps.num * 2;
354 av_log(s, AV_LOG_INFO, "UMF packet too short\n");
356 av_log(s, AV_LOG_INFO, "UMF packet missing\n");
358 // set a fallback value, 60000/1001 is specified for audio-only files
359 // so use that regardless of why we do not know the video frame rate.
360 if (!main_timebase.num || !main_timebase.den)
361 main_timebase = (AVRational){1001, 60000};
362 for (i = 0; i < s->nb_streams; i++) {
363 AVStream *st = s->streams[i];
364 av_set_pts_info(st, 32, main_timebase.num, main_timebase.den);
371 if (!max_interval-- || url_feof(pb)) \
373 tmp = tmp << 8 | get_byte(pb); \
377 * \brief resync the stream on the next media packet with specified properties
378 * \param max_interval how many bytes to search for matching packet at most
379 * \param track track id the media packet must belong to, -1 for any
380 * \param timestamp minimum timestamp (== field number) the packet must have, -1 for any
381 * \return timestamp of packet found
383 static int64_t gxf_resync_media(AVFormatContext *s, uint64_t max_interval, int track, int timestamp) {
386 uint64_t last_found_pos = 0;
388 int64_t cur_timestamp = AV_NOPTS_VALUE;
390 ByteIOContext *pb = s->pb;
399 last_pos = url_ftell(pb);
400 url_fseek(pb, -5, SEEK_CUR);
401 if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) {
402 url_fseek(pb, last_pos, SEEK_SET);
406 cur_track = get_byte(pb);
407 cur_timestamp = get_be32(pb);
408 last_found_pos = url_ftell(pb) - 16 - 6;
409 if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) {
410 url_fseek(pb, last_pos, SEEK_SET);
415 url_fseek(pb, last_found_pos, SEEK_SET);
416 return cur_timestamp;
419 static int gxf_packet(AVFormatContext *s, AVPacket *pkt) {
420 ByteIOContext *pb = s->pb;
423 while (!url_feof(pb)) {
425 int track_type, track_id, ret;
426 int field_nr, field_info, skip = 0;
428 if (!parse_packet_header(pb, &pkt_type, &pkt_len)) {
430 av_log(s, AV_LOG_ERROR, "sync lost\n");
433 if (pkt_type == PKT_FLT) {
434 gxf_read_index(s, pkt_len);
437 if (pkt_type != PKT_MEDIA) {
438 url_fskip(pb, pkt_len);
442 av_log(s, AV_LOG_ERROR, "invalid media packet length\n");
446 track_type = get_byte(pb);
447 track_id = get_byte(pb);
448 stream_index = get_sindex(s, track_id, track_type);
449 if (stream_index < 0)
451 st = s->streams[stream_index];
452 field_nr = get_be32(pb);
453 field_info = get_be32(pb);
454 get_be32(pb); // "timeline" field number
455 get_byte(pb); // flags
456 get_byte(pb); // reserved
457 if (st->codec->codec_id == CODEC_ID_PCM_S24LE ||
458 st->codec->codec_id == CODEC_ID_PCM_S16LE) {
459 int first = field_info >> 16;
460 int last = field_info & 0xffff; // last is exclusive
461 int bps = av_get_bits_per_sample(st->codec->codec_id)>>3;
462 if (first <= last && last*bps <= pkt_len) {
463 url_fskip(pb, first*bps);
464 skip = pkt_len - last*bps;
465 pkt_len = (last-first)*bps;
467 av_log(s, AV_LOG_ERROR, "invalid first and last sample values\n");
469 ret = av_get_packet(pb, pkt, pkt_len);
472 pkt->stream_index = stream_index;
479 static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {
481 uint64_t maxlen = 100 * 1024 * 1024;
482 AVStream *st = s->streams[0];
483 int64_t start_time = s->streams[stream_index]->start_time;
486 if (timestamp < start_time) timestamp = start_time;
487 idx = av_index_search_timestamp(st, timestamp - start_time,
488 AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
491 pos = st->index_entries[idx].pos;
492 if (idx < st->nb_index_entries - 2)
493 maxlen = st->index_entries[idx + 2].pos - pos;
494 maxlen = FFMAX(maxlen, 200 * 1024);
495 url_fseek(s->pb, pos, SEEK_SET);
496 found = gxf_resync_media(s, maxlen, -1, timestamp);
497 if (FFABS(found - timestamp) > 4)
502 static int64_t gxf_read_timestamp(AVFormatContext *s, int stream_index,
503 int64_t *pos, int64_t pos_limit) {
504 ByteIOContext *pb = s->pb;
506 url_fseek(pb, *pos, SEEK_SET);
507 res = gxf_resync_media(s, pos_limit - *pos, -1, -1);
508 *pos = url_ftell(pb);
512 AVInputFormat gxf_demuxer = {
514 NULL_IF_CONFIG_SMALL("GXF format"),