bbf0a604d9ded1132f5b05913b9d338a56a3113d
[libav.git] / libavformat / gxf.c
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 "libavutil/common.h"
23 #include "avformat.h"
24 #include "gxf.h"
25
26 struct gxf_stream_info {
27 int64_t first_field;
28 int64_t last_field;
29 AVRational frames_per_second;
30 int32_t fields_per_frame;
31 };
32
33 /**
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
39 */
40 static int parse_packet_header(ByteIOContext *pb, pkt_type_t *type, int *length) {
41 if (get_be32(pb))
42 return 0;
43 if (get_byte(pb) != 1)
44 return 0;
45 *type = get_byte(pb);
46 *length = get_be32(pb);
47 if ((*length >> 24) || *length < 16)
48 return 0;
49 *length -= 16;
50 if (get_be32(pb))
51 return 0;
52 if (get_byte(pb) != 0xe1)
53 return 0;
54 if (get_byte(pb) != 0xe2)
55 return 0;
56 return 1;
57 }
58
59 /**
60 * \brief check if file starts with a PKT_MAP header
61 */
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;
68 return 0;
69 }
70
71 /**
72 * \brief gets the stream index for the track with the specified id, creates new
73 * stream if not found
74 * \param stream id of stream to find / add
75 * \param format stream format identifier
76 */
77 static int get_sindex(AVFormatContext *s, int id, int format) {
78 int i;
79 AVStream *st = NULL;
80 for (i = 0; i < s->nb_streams; i++) {
81 if (s->streams[i]->id == id)
82 return i;
83 }
84 st = av_new_stream(s, id);
85 if (!st)
86 return AVERROR(ENOMEM);
87 switch (format) {
88 case 3:
89 case 4:
90 st->codec->codec_type = CODEC_TYPE_VIDEO;
91 st->codec->codec_id = CODEC_ID_MJPEG;
92 break;
93 case 13:
94 case 15:
95 st->codec->codec_type = CODEC_TYPE_VIDEO;
96 st->codec->codec_id = CODEC_ID_DVVIDEO;
97 break;
98 case 14:
99 case 16:
100 st->codec->codec_type = CODEC_TYPE_VIDEO;
101 st->codec->codec_id = CODEC_ID_DVVIDEO;
102 break;
103 case 11:
104 case 12:
105 case 20:
106 st->codec->codec_type = CODEC_TYPE_VIDEO;
107 st->codec->codec_id = CODEC_ID_MPEG2VIDEO;
108 st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
109 break;
110 case 22:
111 case 23:
112 st->codec->codec_type = CODEC_TYPE_VIDEO;
113 st->codec->codec_id = CODEC_ID_MPEG1VIDEO;
114 st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
115 break;
116 case 9:
117 st->codec->codec_type = CODEC_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;
124 break;
125 case 10:
126 st->codec->codec_type = CODEC_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;
133 break;
134 case 17:
135 st->codec->codec_type = CODEC_TYPE_AUDIO;
136 st->codec->codec_id = CODEC_ID_AC3;
137 st->codec->channels = 2;
138 st->codec->sample_rate = 48000;
139 break;
140 // timecode tracks:
141 case 7:
142 case 8:
143 case 24:
144 st->codec->codec_type = CODEC_TYPE_DATA;
145 st->codec->codec_id = CODEC_ID_NONE;
146 break;
147 default:
148 st->codec->codec_type = CODEC_TYPE_UNKNOWN;
149 st->codec->codec_id = CODEC_ID_NONE;
150 break;
151 }
152 return s->nb_streams - 1;
153 }
154
155 /**
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
159 */
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;
163 while (*len >= 2) {
164 mat_tag_t tag = get_byte(pb);
165 int tlen = get_byte(pb);
166 *len -= 2;
167 if (tlen > *len)
168 return;
169 *len -= tlen;
170 if (tlen == 4) {
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;
176 } else
177 url_fskip(pb, tlen);
178 }
179 }
180
181 /**
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
185 */
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
190 }
191
192 /**
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
196 */
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);
201 return map[idx];
202 }
203
204 /**
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
208 */
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;
212 while (*len >= 2) {
213 track_tag_t tag = get_byte(pb);
214 int tlen = get_byte(pb);
215 *len -= 2;
216 if (tlen > *len)
217 return;
218 *len -= tlen;
219 if (tlen == 4) {
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;
225 } else
226 url_fskip(pb, tlen);
227 }
228 }
229
230 /**
231 * \brief read index from FLT packet into stream 0 av_index
232 */
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);
238 int i;
239 pkt_len -= 8;
240 if (map_cnt > 1000) {
241 av_log(s, AV_LOG_ERROR, "too many index entries %u (%x)\n", map_cnt, map_cnt);
242 map_cnt = 1000;
243 }
244 if (pkt_len < 4 * map_cnt) {
245 av_log(s, AV_LOG_ERROR, "invalid index length\n");
246 url_fskip(pb, pkt_len);
247 return;
248 }
249 pkt_len -= 4 * map_cnt;
250 av_add_index_entry(st, 0, 0, 0, 0, 0);
251 for (i = 0; i < map_cnt; i++)
252 av_add_index_entry(st, (uint64_t)get_le32(pb) * 1024,
253 i * (uint64_t)fields_per_map + 1, 0, 0, 0);
254 url_fskip(pb, pkt_len);
255 }
256
257 static int gxf_header(AVFormatContext *s, AVFormatParameters *ap) {
258 ByteIOContext *pb = s->pb;
259 pkt_type_t pkt_type;
260 int map_len;
261 int len;
262 AVRational main_timebase = {0, 0};
263 struct gxf_stream_info si;
264 int i;
265 if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) {
266 av_log(s, AV_LOG_ERROR, "map packet not found\n");
267 return 0;
268 }
269 map_len -= 2;
270 if (get_byte(pb) != 0x0e0 || get_byte(pb) != 0xff) {
271 av_log(s, AV_LOG_ERROR, "unknown version or invalid map preamble\n");
272 return 0;
273 }
274 map_len -= 2;
275 len = get_be16(pb); // length of material data section
276 if (len > map_len) {
277 av_log(s, AV_LOG_ERROR, "material data longer than map data\n");
278 return 0;
279 }
280 map_len -= len;
281 gxf_material_tags(pb, &len, &si);
282 url_fskip(pb, len);
283 map_len -= 2;
284 len = get_be16(pb); // length of track description
285 if (len > map_len) {
286 av_log(s, AV_LOG_ERROR, "track description longer than map data\n");
287 return 0;
288 }
289 map_len -= len;
290 while (len > 0) {
291 int track_type, track_id, track_len;
292 AVStream *st;
293 int idx;
294 len -= 4;
295 track_type = get_byte(pb);
296 track_id = get_byte(pb);
297 track_len = get_be16(pb);
298 len -= track_len;
299 gxf_track_tags(pb, &track_len, &si);
300 url_fskip(pb, track_len);
301 if (!(track_type & 0x80)) {
302 av_log(s, AV_LOG_ERROR, "invalid track type %x\n", track_type);
303 continue;
304 }
305 track_type &= 0x7f;
306 if ((track_id & 0xc0) != 0xc0) {
307 av_log(s, AV_LOG_ERROR, "invalid track id %x\n", track_id);
308 continue;
309 }
310 track_id &= 0x3f;
311 idx = get_sindex(s, track_id, track_type);
312 if (idx < 0) continue;
313 st = s->streams[idx];
314 if (!main_timebase.num || !main_timebase.den) {
315 main_timebase.num = si.frames_per_second.den;
316 main_timebase.den = si.frames_per_second.num * si.fields_per_frame;
317 }
318 st->start_time = si.first_field;
319 if (si.first_field != AV_NOPTS_VALUE && si.last_field != AV_NOPTS_VALUE)
320 st->duration = si.last_field - si.first_field;
321 }
322 if (len < 0)
323 av_log(s, AV_LOG_ERROR, "invalid track description length specified\n");
324 if (map_len)
325 url_fskip(pb, map_len);
326 if (!parse_packet_header(pb, &pkt_type, &len)) {
327 av_log(s, AV_LOG_ERROR, "sync lost in header\n");
328 return -1;
329 }
330 if (pkt_type == PKT_FLT) {
331 gxf_read_index(s, len);
332 if (!parse_packet_header(pb, &pkt_type, &len)) {
333 av_log(s, AV_LOG_ERROR, "sync lost in header\n");
334 return -1;
335 }
336 }
337 if (pkt_type == PKT_UMF) {
338 if (len >= 0x39) {
339 AVRational fps;
340 len -= 0x39;
341 url_fskip(pb, 5); // preamble
342 url_fskip(pb, 0x30); // payload description
343 fps = fps_umf2avr(get_le32(pb));
344 if (!main_timebase.num || !main_timebase.den) {
345 // this may not always be correct, but simply the best we can get
346 main_timebase.num = fps.den;
347 main_timebase.den = fps.num;
348 }
349 } else
350 av_log(s, AV_LOG_INFO, "UMF packet too short\n");
351 } else
352 av_log(s, AV_LOG_INFO, "UMF packet missing\n");
353 url_fskip(pb, len);
354 if (!main_timebase.num || !main_timebase.den)
355 main_timebase = (AVRational){1, 50}; // set some arbitrary fallback
356 for (i = 0; i < s->nb_streams; i++) {
357 AVStream *st = s->streams[i];
358 av_set_pts_info(st, 32, main_timebase.num, main_timebase.den);
359 }
360 return 0;
361 }
362
363 #define READ_ONE() \
364 { \
365 if (!max_interval-- || url_feof(pb)) \
366 goto out; \
367 tmp = tmp << 8 | get_byte(pb); \
368 }
369
370 /**
371 * \brief resync the stream on the next media packet with specified properties
372 * \param max_interval how many bytes to search for matching packet at most
373 * \param track track id the media packet must belong to, -1 for any
374 * \param timestamp minimum timestamp (== field number) the packet must have, -1 for any
375 * \return timestamp of packet found
376 */
377 static int64_t gxf_resync_media(AVFormatContext *s, uint64_t max_interval, int track, int timestamp) {
378 uint32_t tmp;
379 uint64_t last_pos;
380 uint64_t last_found_pos = 0;
381 int cur_track;
382 int64_t cur_timestamp = AV_NOPTS_VALUE;
383 int len;
384 ByteIOContext *pb = s->pb;
385 pkt_type_t type;
386 tmp = get_be32(pb);
387 start:
388 while (tmp)
389 READ_ONE();
390 READ_ONE();
391 if (tmp != 1)
392 goto start;
393 last_pos = url_ftell(pb);
394 url_fseek(pb, -5, SEEK_CUR);
395 if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) {
396 url_fseek(pb, last_pos, SEEK_SET);
397 goto start;
398 }
399 get_byte(pb);
400 cur_track = get_byte(pb);
401 cur_timestamp = get_be32(pb);
402 last_found_pos = url_ftell(pb) - 16 - 6;
403 if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) {
404 url_fseek(pb, last_pos, SEEK_SET);
405 goto start;
406 }
407 out:
408 if (last_found_pos)
409 url_fseek(pb, last_found_pos, SEEK_SET);
410 return cur_timestamp;
411 }
412
413 static int gxf_packet(AVFormatContext *s, AVPacket *pkt) {
414 ByteIOContext *pb = s->pb;
415 pkt_type_t pkt_type;
416 int pkt_len;
417 while (!url_feof(pb)) {
418 AVStream *st;
419 int track_type, track_id, ret;
420 int field_nr, field_info, skip = 0;
421 int stream_index;
422 if (!parse_packet_header(pb, &pkt_type, &pkt_len)) {
423 if (!url_feof(pb))
424 av_log(s, AV_LOG_ERROR, "sync lost\n");
425 return -1;
426 }
427 if (pkt_type == PKT_FLT) {
428 gxf_read_index(s, pkt_len);
429 continue;
430 }
431 if (pkt_type != PKT_MEDIA) {
432 url_fskip(pb, pkt_len);
433 continue;
434 }
435 if (pkt_len < 16) {
436 av_log(s, AV_LOG_ERROR, "invalid media packet length\n");
437 continue;
438 }
439 pkt_len -= 16;
440 track_type = get_byte(pb);
441 track_id = get_byte(pb);
442 stream_index = get_sindex(s, track_id, track_type);
443 if (stream_index < 0)
444 return stream_index;
445 st = s->streams[stream_index];
446 field_nr = get_be32(pb);
447 field_info = get_be32(pb);
448 get_be32(pb); // "timeline" field number
449 get_byte(pb); // flags
450 get_byte(pb); // reserved
451 if (st->codec->codec_id == CODEC_ID_PCM_S24LE ||
452 st->codec->codec_id == CODEC_ID_PCM_S16LE) {
453 int first = field_info >> 16;
454 int last = field_info & 0xffff; // last is exclusive
455 int bps = av_get_bits_per_sample(st->codec->codec_id)>>3;
456 if (first <= last && last*bps <= pkt_len) {
457 url_fskip(pb, first*bps);
458 skip = pkt_len - last*bps;
459 pkt_len = (last-first)*bps;
460 } else
461 av_log(s, AV_LOG_ERROR, "invalid first and last sample values\n");
462 }
463 ret = av_get_packet(pb, pkt, pkt_len);
464 if (skip)
465 url_fskip(pb, skip);
466 pkt->stream_index = stream_index;
467 pkt->dts = field_nr;
468 return ret;
469 }
470 return AVERROR(EIO);
471 }
472
473 static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {
474 uint64_t pos;
475 uint64_t maxlen = 100 * 1024 * 1024;
476 AVStream *st = s->streams[0];
477 int64_t start_time = s->streams[stream_index]->start_time;
478 int64_t found;
479 int idx;
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);
483 if (idx < 0)
484 return -1;
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 (FFABS(found - timestamp) > 4)
492 return -1;
493 return 0;
494 }
495
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;
499 int64_t res;
500 url_fseek(pb, *pos, SEEK_SET);
501 res = gxf_resync_media(s, pos_limit - *pos, -1, -1);
502 *pos = url_ftell(pb);
503 return res;
504 }
505
506 AVInputFormat gxf_demuxer = {
507 "gxf",
508 NULL_IF_CONFIG_SMALL("GXF format"),
509 0,
510 gxf_probe,
511 gxf_header,
512 gxf_packet,
513 NULL,
514 gxf_seek,
515 gxf_read_timestamp,
516 };