blob: 399f745bc76a6a247b94c1502ade1af62bf03e11
1 | /* |
2 | * GXF demuxer. |
3 | * Copyright (c) 2006 Reimar Doeffinger |
4 | * |
5 | * This file is part of FFmpeg. |
6 | * |
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. |
11 | * |
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. |
16 | * |
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 |
20 | */ |
21 | |
22 | #include <inttypes.h> |
23 | |
24 | #include "libavutil/channel_layout.h" |
25 | #include "libavutil/common.h" |
26 | #include "avformat.h" |
27 | #include "internal.h" |
28 | #include "gxf.h" |
29 | #include "libavcodec/mpeg12data.h" |
30 | |
31 | struct gxf_stream_info { |
32 | int64_t first_field; |
33 | int64_t last_field; |
34 | AVRational frames_per_second; |
35 | int32_t fields_per_frame; |
36 | int64_t track_aux_data; |
37 | }; |
38 | |
39 | /** |
40 | * @brief parse gxf timecode and add it to metadata |
41 | */ |
42 | static int add_timecode_metadata(AVDictionary **pm, const char *key, uint32_t timecode, int fields_per_frame) |
43 | { |
44 | char tmp[128]; |
45 | int field = timecode & 0xff; |
46 | int frame = fields_per_frame ? field / fields_per_frame : field; |
47 | int second = (timecode >> 8) & 0xff; |
48 | int minute = (timecode >> 16) & 0xff; |
49 | int hour = (timecode >> 24) & 0x1f; |
50 | int drop = (timecode >> 29) & 1; |
51 | // bit 30: color_frame, unused |
52 | // ignore invalid time code |
53 | if (timecode >> 31) |
54 | return 0; |
55 | snprintf(tmp, sizeof(tmp), "%02d:%02d:%02d%c%02d", |
56 | hour, minute, second, drop ? ';' : ':', frame); |
57 | return av_dict_set(pm, key, tmp, 0); |
58 | } |
59 | |
60 | /** |
61 | * @brief parses a packet header, extracting type and length |
62 | * @param pb AVIOContext to read header from |
63 | * @param type detected packet type is stored here |
64 | * @param length detected packet length, excluding header is stored here |
65 | * @return 0 if header not found or contains invalid data, 1 otherwise |
66 | */ |
67 | static int parse_packet_header(AVIOContext *pb, GXFPktType *type, int *length) { |
68 | if (avio_rb32(pb)) |
69 | return 0; |
70 | if (avio_r8(pb) != 1) |
71 | return 0; |
72 | *type = avio_r8(pb); |
73 | *length = avio_rb32(pb); |
74 | if ((*length >> 24) || *length < 16) |
75 | return 0; |
76 | *length -= 16; |
77 | if (avio_rb32(pb)) |
78 | return 0; |
79 | if (avio_r8(pb) != 0xe1) |
80 | return 0; |
81 | if (avio_r8(pb) != 0xe2) |
82 | return 0; |
83 | return 1; |
84 | } |
85 | |
86 | /** |
87 | * @brief check if file starts with a PKT_MAP header |
88 | */ |
89 | static int gxf_probe(AVProbeData *p) { |
90 | static const uint8_t startcode[] = {0, 0, 0, 0, 1, 0xbc}; // start with map packet |
91 | 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; |
95 | return 0; |
96 | } |
97 | |
98 | /** |
99 | * @brief gets the stream index for the track with the specified id, creates new |
100 | * stream if not found |
101 | * @param id id of stream to find / add |
102 | * @param format stream format identifier |
103 | */ |
104 | static int get_sindex(AVFormatContext *s, int id, int format) { |
105 | int i; |
106 | AVStream *st = NULL; |
107 | i = ff_find_stream_index(s, id); |
108 | if (i >= 0) |
109 | return i; |
110 | st = avformat_new_stream(s, NULL); |
111 | if (!st) |
112 | return AVERROR(ENOMEM); |
113 | st->id = id; |
114 | switch (format) { |
115 | case 3: |
116 | case 4: |
117 | st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO; |
118 | st->codecpar->codec_id = AV_CODEC_ID_MJPEG; |
119 | break; |
120 | case 13: |
121 | case 14: |
122 | case 15: |
123 | case 16: |
124 | case 25: |
125 | st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO; |
126 | st->codecpar->codec_id = AV_CODEC_ID_DVVIDEO; |
127 | break; |
128 | case 11: |
129 | case 12: |
130 | case 20: |
131 | st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO; |
132 | st->codecpar->codec_id = AV_CODEC_ID_MPEG2VIDEO; |
133 | st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc. |
134 | break; |
135 | case 22: |
136 | case 23: |
137 | st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO; |
138 | st->codecpar->codec_id = AV_CODEC_ID_MPEG1VIDEO; |
139 | st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc. |
140 | break; |
141 | case 9: |
142 | st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; |
143 | st->codecpar->codec_id = AV_CODEC_ID_PCM_S24LE; |
144 | st->codecpar->channels = 1; |
145 | st->codecpar->channel_layout = AV_CH_LAYOUT_MONO; |
146 | st->codecpar->sample_rate = 48000; |
147 | st->codecpar->bit_rate = 3 * 1 * 48000 * 8; |
148 | st->codecpar->block_align = 3 * 1; |
149 | st->codecpar->bits_per_coded_sample = 24; |
150 | break; |
151 | case 10: |
152 | st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; |
153 | st->codecpar->codec_id = AV_CODEC_ID_PCM_S16LE; |
154 | st->codecpar->channels = 1; |
155 | st->codecpar->channel_layout = AV_CH_LAYOUT_MONO; |
156 | st->codecpar->sample_rate = 48000; |
157 | st->codecpar->bit_rate = 2 * 1 * 48000 * 8; |
158 | st->codecpar->block_align = 2 * 1; |
159 | st->codecpar->bits_per_coded_sample = 16; |
160 | break; |
161 | case 17: |
162 | st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; |
163 | st->codecpar->codec_id = AV_CODEC_ID_AC3; |
164 | st->codecpar->channels = 2; |
165 | st->codecpar->channel_layout = AV_CH_LAYOUT_STEREO; |
166 | st->codecpar->sample_rate = 48000; |
167 | break; |
168 | case 26: /* AVCi50 / AVCi100 (AVC Intra) */ |
169 | case 29: /* AVCHD */ |
170 | st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO; |
171 | st->codecpar->codec_id = AV_CODEC_ID_H264; |
172 | st->need_parsing = AVSTREAM_PARSE_HEADERS; |
173 | break; |
174 | // timecode tracks: |
175 | case 7: |
176 | case 8: |
177 | case 24: |
178 | st->codecpar->codec_type = AVMEDIA_TYPE_DATA; |
179 | st->codecpar->codec_id = AV_CODEC_ID_NONE; |
180 | break; |
181 | case 30: |
182 | st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO; |
183 | st->codecpar->codec_id = AV_CODEC_ID_DNXHD; |
184 | break; |
185 | default: |
186 | st->codecpar->codec_type = AVMEDIA_TYPE_UNKNOWN; |
187 | st->codecpar->codec_id = AV_CODEC_ID_NONE; |
188 | break; |
189 | } |
190 | return s->nb_streams - 1; |
191 | } |
192 | |
193 | /** |
194 | * @brief filters out interesting tags from material information. |
195 | * @param len length of tag section, will be adjusted to contain remaining bytes |
196 | * @param si struct to store collected information into |
197 | */ |
198 | static void gxf_material_tags(AVIOContext *pb, int *len, struct gxf_stream_info *si) { |
199 | si->first_field = AV_NOPTS_VALUE; |
200 | si->last_field = AV_NOPTS_VALUE; |
201 | while (*len >= 2) { |
202 | GXFMatTag tag = avio_r8(pb); |
203 | int tlen = avio_r8(pb); |
204 | *len -= 2; |
205 | if (tlen > *len) |
206 | return; |
207 | *len -= tlen; |
208 | if (tlen == 4) { |
209 | uint32_t value = avio_rb32(pb); |
210 | if (tag == MAT_FIRST_FIELD) |
211 | si->first_field = value; |
212 | else if (tag == MAT_LAST_FIELD) |
213 | si->last_field = value; |
214 | } else |
215 | avio_skip(pb, tlen); |
216 | } |
217 | } |
218 | |
219 | static const AVRational frame_rate_tab[] = { |
220 | { 60, 1}, |
221 | {60000, 1001}, |
222 | { 50, 1}, |
223 | { 30, 1}, |
224 | {30000, 1001}, |
225 | { 25, 1}, |
226 | { 24, 1}, |
227 | {24000, 1001}, |
228 | { 0, 0}, |
229 | }; |
230 | |
231 | /** |
232 | * @brief convert fps tag value to AVRational fps |
233 | * @param fps fps value from tag |
234 | * @return fps as AVRational, or 0 / 0 if unknown |
235 | */ |
236 | static AVRational fps_tag2avr(int32_t fps) { |
237 | if (fps < 1 || fps > 9) fps = 9; |
238 | return frame_rate_tab[fps - 1]; |
239 | } |
240 | |
241 | /** |
242 | * @brief convert UMF attributes flags to AVRational fps |
243 | * @param flags UMF flags to convert |
244 | * @return fps as AVRational, or 0 / 0 if unknown |
245 | */ |
246 | static AVRational fps_umf2avr(uint32_t flags) { |
247 | static const AVRational map[] = {{50, 1}, {60000, 1001}, {24, 1}, |
248 | {25, 1}, {30000, 1001}}; |
249 | int idx = av_log2((flags & 0x7c0) >> 6); |
250 | return map[idx]; |
251 | } |
252 | |
253 | /** |
254 | * @brief filters out interesting tags from track information. |
255 | * @param len length of tag section, will be adjusted to contain remaining bytes |
256 | * @param si struct to store collected information into |
257 | */ |
258 | static void gxf_track_tags(AVIOContext *pb, int *len, struct gxf_stream_info *si) { |
259 | si->frames_per_second = (AVRational){0, 0}; |
260 | si->fields_per_frame = 0; |
261 | si->track_aux_data = 0x80000000; |
262 | while (*len >= 2) { |
263 | GXFTrackTag tag = avio_r8(pb); |
264 | int tlen = avio_r8(pb); |
265 | *len -= 2; |
266 | if (tlen > *len) |
267 | return; |
268 | *len -= tlen; |
269 | if (tlen == 4) { |
270 | uint32_t value = avio_rb32(pb); |
271 | if (tag == TRACK_FPS) |
272 | si->frames_per_second = fps_tag2avr(value); |
273 | else if (tag == TRACK_FPF && (value == 1 || value == 2)) |
274 | si->fields_per_frame = value; |
275 | } else if (tlen == 8 && tag == TRACK_AUX) |
276 | si->track_aux_data = avio_rl64(pb); |
277 | else |
278 | avio_skip(pb, tlen); |
279 | } |
280 | } |
281 | |
282 | /** |
283 | * @brief read index from FLT packet into stream 0 av_index |
284 | */ |
285 | static void gxf_read_index(AVFormatContext *s, int pkt_len) { |
286 | AVIOContext *pb = s->pb; |
287 | AVStream *st; |
288 | uint32_t fields_per_map = avio_rl32(pb); |
289 | uint32_t map_cnt = avio_rl32(pb); |
290 | int i; |
291 | pkt_len -= 8; |
292 | if ((s->flags & AVFMT_FLAG_IGNIDX) || !s->streams) { |
293 | avio_skip(pb, pkt_len); |
294 | return; |
295 | } |
296 | st = s->streams[0]; |
297 | if (map_cnt > 1000) { |
298 | av_log(s, AV_LOG_ERROR, |
299 | "too many index entries %"PRIu32" (%"PRIx32")\n", |
300 | map_cnt, map_cnt); |
301 | map_cnt = 1000; |
302 | } |
303 | if (pkt_len < 4 * map_cnt) { |
304 | av_log(s, AV_LOG_ERROR, "invalid index length\n"); |
305 | avio_skip(pb, pkt_len); |
306 | return; |
307 | } |
308 | pkt_len -= 4 * map_cnt; |
309 | av_add_index_entry(st, 0, 0, 0, 0, 0); |
310 | for (i = 0; i < map_cnt; i++) |
311 | av_add_index_entry(st, (uint64_t)avio_rl32(pb) * 1024, |
312 | i * (uint64_t)fields_per_map + 1, 0, 0, 0); |
313 | avio_skip(pb, pkt_len); |
314 | } |
315 | |
316 | static int gxf_header(AVFormatContext *s) { |
317 | AVIOContext *pb = s->pb; |
318 | GXFPktType pkt_type; |
319 | int map_len; |
320 | int len; |
321 | AVRational main_timebase = {0, 0}; |
322 | struct gxf_stream_info *si = s->priv_data; |
323 | int i; |
324 | if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) { |
325 | av_log(s, AV_LOG_ERROR, "map packet not found\n"); |
326 | return 0; |
327 | } |
328 | map_len -= 2; |
329 | if (avio_r8(pb) != 0x0e0 || avio_r8(pb) != 0xff) { |
330 | av_log(s, AV_LOG_ERROR, "unknown version or invalid map preamble\n"); |
331 | return 0; |
332 | } |
333 | map_len -= 2; |
334 | len = avio_rb16(pb); // length of material data section |
335 | if (len > map_len) { |
336 | av_log(s, AV_LOG_ERROR, "material data longer than map data\n"); |
337 | return 0; |
338 | } |
339 | map_len -= len; |
340 | gxf_material_tags(pb, &len, si); |
341 | avio_skip(pb, len); |
342 | map_len -= 2; |
343 | len = avio_rb16(pb); // length of track description |
344 | if (len > map_len) { |
345 | av_log(s, AV_LOG_ERROR, "track description longer than map data\n"); |
346 | return 0; |
347 | } |
348 | map_len -= len; |
349 | while (len > 0) { |
350 | int track_type, track_id, track_len; |
351 | AVStream *st; |
352 | int idx; |
353 | len -= 4; |
354 | track_type = avio_r8(pb); |
355 | track_id = avio_r8(pb); |
356 | track_len = avio_rb16(pb); |
357 | len -= track_len; |
358 | if (!(track_type & 0x80)) { |
359 | av_log(s, AV_LOG_ERROR, "invalid track type %x\n", track_type); |
360 | continue; |
361 | } |
362 | track_type &= 0x7f; |
363 | if ((track_id & 0xc0) != 0xc0) { |
364 | av_log(s, AV_LOG_ERROR, "invalid track id %x\n", track_id); |
365 | continue; |
366 | } |
367 | track_id &= 0x3f; |
368 | gxf_track_tags(pb, &track_len, si); |
369 | // check for timecode tracks |
370 | if (track_type == 7 || track_type == 8 || track_type == 24) { |
371 | add_timecode_metadata(&s->metadata, "timecode", |
372 | si->track_aux_data & 0xffffffff, |
373 | si->fields_per_frame); |
374 | |
375 | } |
376 | avio_skip(pb, track_len); |
377 | |
378 | idx = get_sindex(s, track_id, track_type); |
379 | if (idx < 0) continue; |
380 | st = s->streams[idx]; |
381 | if (!main_timebase.num || !main_timebase.den) { |
382 | main_timebase.num = si->frames_per_second.den; |
383 | main_timebase.den = si->frames_per_second.num * 2; |
384 | } |
385 | st->start_time = si->first_field; |
386 | if (si->first_field != AV_NOPTS_VALUE && si->last_field != AV_NOPTS_VALUE) |
387 | st->duration = si->last_field - si->first_field; |
388 | } |
389 | if (len < 0) |
390 | av_log(s, AV_LOG_ERROR, "invalid track description length specified\n"); |
391 | if (map_len) |
392 | avio_skip(pb, map_len); |
393 | if (!parse_packet_header(pb, &pkt_type, &len)) { |
394 | av_log(s, AV_LOG_ERROR, "sync lost in header\n"); |
395 | return -1; |
396 | } |
397 | if (pkt_type == PKT_FLT) { |
398 | gxf_read_index(s, len); |
399 | if (!parse_packet_header(pb, &pkt_type, &len)) { |
400 | av_log(s, AV_LOG_ERROR, "sync lost in header\n"); |
401 | return -1; |
402 | } |
403 | } |
404 | if (pkt_type == PKT_UMF) { |
405 | if (len >= 0x39) { |
406 | AVRational fps; |
407 | len -= 0x39; |
408 | avio_skip(pb, 5); // preamble |
409 | avio_skip(pb, 0x30); // payload description |
410 | fps = fps_umf2avr(avio_rl32(pb)); |
411 | if (!main_timebase.num || !main_timebase.den) { |
412 | av_log(s, AV_LOG_WARNING, "No FPS track tag, using UMF fps tag." |
413 | " This might give wrong results.\n"); |
414 | // this may not always be correct, but simply the best we can get |
415 | main_timebase.num = fps.den; |
416 | main_timebase.den = fps.num * 2; |
417 | } |
418 | |
419 | if (len >= 0x18) { |
420 | len -= 0x18; |
421 | avio_skip(pb, 0x10); |
422 | add_timecode_metadata(&s->metadata, "timecode_at_mark_in", |
423 | avio_rl32(pb), si->fields_per_frame); |
424 | add_timecode_metadata(&s->metadata, "timecode_at_mark_out", |
425 | avio_rl32(pb), si->fields_per_frame); |
426 | } |
427 | } else |
428 | av_log(s, AV_LOG_INFO, "UMF packet too short\n"); |
429 | } else |
430 | av_log(s, AV_LOG_INFO, "UMF packet missing\n"); |
431 | avio_skip(pb, len); |
432 | // set a fallback value, 60000/1001 is specified for audio-only files |
433 | // so use that regardless of why we do not know the video frame rate. |
434 | if (!main_timebase.num || !main_timebase.den) |
435 | main_timebase = (AVRational){1001, 60000}; |
436 | for (i = 0; i < s->nb_streams; i++) { |
437 | AVStream *st = s->streams[i]; |
438 | avpriv_set_pts_info(st, 32, main_timebase.num, main_timebase.den); |
439 | } |
440 | return 0; |
441 | } |
442 | |
443 | #define READ_ONE() \ |
444 | { \ |
445 | if (!max_interval-- || avio_feof(pb)) \ |
446 | goto out; \ |
447 | tmp = tmp << 8 | avio_r8(pb); \ |
448 | } |
449 | |
450 | /** |
451 | * @brief resync the stream on the next media packet with specified properties |
452 | * @param max_interval how many bytes to search for matching packet at most |
453 | * @param track track id the media packet must belong to, -1 for any |
454 | * @param timestamp minimum timestamp (== field number) the packet must have, -1 for any |
455 | * @return timestamp of packet found |
456 | */ |
457 | static int64_t gxf_resync_media(AVFormatContext *s, uint64_t max_interval, int track, int timestamp) { |
458 | uint32_t tmp; |
459 | uint64_t last_pos; |
460 | uint64_t last_found_pos = 0; |
461 | int cur_track; |
462 | int64_t cur_timestamp = AV_NOPTS_VALUE; |
463 | int len; |
464 | AVIOContext *pb = s->pb; |
465 | GXFPktType type; |
466 | tmp = avio_rb32(pb); |
467 | start: |
468 | while (tmp) |
469 | READ_ONE(); |
470 | READ_ONE(); |
471 | if (tmp != 1) |
472 | goto start; |
473 | last_pos = avio_tell(pb); |
474 | if (avio_seek(pb, -5, SEEK_CUR) < 0) |
475 | goto out; |
476 | if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) { |
477 | if (avio_seek(pb, last_pos, SEEK_SET) < 0) |
478 | goto out; |
479 | goto start; |
480 | } |
481 | avio_r8(pb); |
482 | cur_track = avio_r8(pb); |
483 | cur_timestamp = avio_rb32(pb); |
484 | last_found_pos = avio_tell(pb) - 16 - 6; |
485 | if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) { |
486 | if (avio_seek(pb, last_pos, SEEK_SET) >= 0) |
487 | goto start; |
488 | } |
489 | out: |
490 | if (last_found_pos) |
491 | avio_seek(pb, last_found_pos, SEEK_SET); |
492 | return cur_timestamp; |
493 | } |
494 | |
495 | static int gxf_packet(AVFormatContext *s, AVPacket *pkt) { |
496 | AVIOContext *pb = s->pb; |
497 | GXFPktType pkt_type; |
498 | int pkt_len; |
499 | struct gxf_stream_info *si = s->priv_data; |
500 | |
501 | while (!pb->eof_reached) { |
502 | AVStream *st; |
503 | int track_type, track_id, ret; |
504 | int field_nr, field_info, skip = 0; |
505 | int stream_index; |
506 | if (!parse_packet_header(pb, &pkt_type, &pkt_len)) { |
507 | if (!avio_feof(pb)) |
508 | av_log(s, AV_LOG_ERROR, "sync lost\n"); |
509 | return -1; |
510 | } |
511 | if (pkt_type == PKT_FLT) { |
512 | gxf_read_index(s, pkt_len); |
513 | continue; |
514 | } |
515 | if (pkt_type != PKT_MEDIA) { |
516 | avio_skip(pb, pkt_len); |
517 | continue; |
518 | } |
519 | if (pkt_len < 16) { |
520 | av_log(s, AV_LOG_ERROR, "invalid media packet length\n"); |
521 | continue; |
522 | } |
523 | pkt_len -= 16; |
524 | track_type = avio_r8(pb); |
525 | track_id = avio_r8(pb); |
526 | stream_index = get_sindex(s, track_id, track_type); |
527 | if (stream_index < 0) |
528 | return stream_index; |
529 | st = s->streams[stream_index]; |
530 | field_nr = avio_rb32(pb); |
531 | field_info = avio_rb32(pb); |
532 | avio_rb32(pb); // "timeline" field number |
533 | avio_r8(pb); // flags |
534 | avio_r8(pb); // reserved |
535 | if (st->codecpar->codec_id == AV_CODEC_ID_PCM_S24LE || |
536 | st->codecpar->codec_id == AV_CODEC_ID_PCM_S16LE) { |
537 | int first = field_info >> 16; |
538 | int last = field_info & 0xffff; // last is exclusive |
539 | int bps = av_get_bits_per_sample(st->codecpar->codec_id)>>3; |
540 | if (first <= last && last*bps <= pkt_len) { |
541 | avio_skip(pb, first*bps); |
542 | skip = pkt_len - last*bps; |
543 | pkt_len = (last-first)*bps; |
544 | } else |
545 | av_log(s, AV_LOG_ERROR, "invalid first and last sample values\n"); |
546 | } |
547 | ret = av_get_packet(pb, pkt, pkt_len); |
548 | if (skip) |
549 | avio_skip(pb, skip); |
550 | pkt->stream_index = stream_index; |
551 | pkt->dts = field_nr; |
552 | |
553 | //set duration manually for DV or else lavf misdetects the frame rate |
554 | if (st->codecpar->codec_id == AV_CODEC_ID_DVVIDEO) |
555 | pkt->duration = si->fields_per_frame; |
556 | |
557 | return ret; |
558 | } |
559 | return AVERROR_EOF; |
560 | } |
561 | |
562 | static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) { |
563 | int64_t res = 0; |
564 | uint64_t pos; |
565 | uint64_t maxlen = 100 * 1024 * 1024; |
566 | AVStream *st = s->streams[0]; |
567 | int64_t start_time = s->streams[stream_index]->start_time; |
568 | int64_t found; |
569 | int idx; |
570 | if (timestamp < start_time) timestamp = start_time; |
571 | idx = av_index_search_timestamp(st, timestamp - start_time, |
572 | AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD); |
573 | if (idx < 0) |
574 | return -1; |
575 | pos = st->index_entries[idx].pos; |
576 | if (idx < st->nb_index_entries - 2) |
577 | maxlen = st->index_entries[idx + 2].pos - pos; |
578 | maxlen = FFMAX(maxlen, 200 * 1024); |
579 | res = avio_seek(s->pb, pos, SEEK_SET); |
580 | if (res < 0) |
581 | return res; |
582 | found = gxf_resync_media(s, maxlen, -1, timestamp); |
583 | if (FFABS(found - timestamp) > 4) |
584 | return -1; |
585 | return 0; |
586 | } |
587 | |
588 | static int64_t gxf_read_timestamp(AVFormatContext *s, int stream_index, |
589 | int64_t *pos, int64_t pos_limit) { |
590 | AVIOContext *pb = s->pb; |
591 | int64_t res; |
592 | if (avio_seek(pb, *pos, SEEK_SET) < 0) |
593 | return AV_NOPTS_VALUE; |
594 | res = gxf_resync_media(s, pos_limit - *pos, -1, -1); |
595 | *pos = avio_tell(pb); |
596 | return res; |
597 | } |
598 | |
599 | AVInputFormat ff_gxf_demuxer = { |
600 | .name = "gxf", |
601 | .long_name = NULL_IF_CONFIG_SMALL("GXF (General eXchange Format)"), |
602 | .priv_data_size = sizeof(struct gxf_stream_info), |
603 | .read_probe = gxf_probe, |
604 | .read_header = gxf_header, |
605 | .read_packet = gxf_packet, |
606 | .read_seek = gxf_seek, |
607 | .read_timestamp = gxf_read_timestamp, |
608 | }; |
609 |