1 /*
2 * MPEG1/2 demuxer
3 * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
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 "avformat.h"
23 #include "internal.h"
24 #include "mpeg.h"
25
26 #if CONFIG_VOBSUB_DEMUXER
27 # include "subtitles.h"
28 # include "libavutil/bprint.h"
29 #endif
30
31 #undef NDEBUG
32 #include <assert.h>
33 #include "libavutil/avassert.h"
34
35 /*********************************************/
36 /* demux code */
37
38 #define MAX_SYNC_SIZE 100000
39
check_pes(const uint8_t * p,const uint8_t * end)40 static int check_pes(const uint8_t *p, const uint8_t *end)
41 {
42 int pes1;
43 int pes2 = (p[3] & 0xC0) == 0x80 &&
44 (p[4] & 0xC0) != 0x40 &&
45 ((p[4] & 0xC0) == 0x00 ||
46 (p[4] & 0xC0) >> 2 == (p[6] & 0xF0));
47
48 for (p += 3; p < end && *p == 0xFF; p++) ;
49 if ((*p & 0xC0) == 0x40)
50 p += 2;
51
52 if ((*p & 0xF0) == 0x20)
53 pes1 = p[0] & p[2] & p[4] & 1;
54 else if ((*p & 0xF0) == 0x30)
55 pes1 = p[0] & p[2] & p[4] & p[5] & p[7] & p[9] & 1;
56 else
57 pes1 = *p == 0x0F;
58
59 return pes1 || pes2;
60 }
61
check_pack_header(const uint8_t * buf)62 static int check_pack_header(const uint8_t *buf)
63 {
64 return (buf[1] & 0xC0) == 0x40 || (buf[1] & 0xF0) == 0x20;
65 }
66
mpegps_probe(AVProbeData * p)67 static int mpegps_probe(AVProbeData *p)
68 {
69 uint32_t code = -1;
70 int i;
71 int sys = 0, pspack = 0, priv1 = 0, vid = 0;
72 int audio = 0, invalid = 0, score = 0;
73
74 for (i = 0; i < p->buf_size; i++) {
75 code = (code << 8) + p->buf[i];
76 if ((code & 0xffffff00) == 0x100) {
77 int len = p->buf[i + 1] << 8 | p->buf[i + 2];
78 int pes = check_pes(p->buf + i, p->buf + p->buf_size);
79 int pack = check_pack_header(p->buf + i);
80
81 if (code == SYSTEM_HEADER_START_CODE)
82 sys++;
83 else if (code == PACK_START_CODE && pack)
84 pspack++;
85 else if ((code & 0xf0) == VIDEO_ID && pes)
86 vid++;
87 // skip pes payload to avoid start code emulation for private
88 // and audio streams
89 else if ((code & 0xe0) == AUDIO_ID && pes) {audio++; i+=len;}
90 else if (code == PRIVATE_STREAM_1 && pes) {priv1++; i+=len;}
91 else if (code == 0x1fd && pes) vid++; //VC1
92
93 else if ((code & 0xf0) == VIDEO_ID && !pes) invalid++;
94 else if ((code & 0xe0) == AUDIO_ID && !pes) invalid++;
95 else if (code == PRIVATE_STREAM_1 && !pes) invalid++;
96 }
97 }
98
99 if (vid + audio > invalid + 1) /* invalid VDR files nd short PES streams */
100 score = AVPROBE_SCORE_EXTENSION / 2;
101
102 if (sys > invalid && sys * 9 <= pspack * 10)
103 return (audio > 12 || vid > 3 || pspack > 2) ? AVPROBE_SCORE_EXTENSION + 2
104 : AVPROBE_SCORE_EXTENSION / 2 + 1; // 1 more than mp3
105 if (pspack > invalid && (priv1 + vid + audio) * 10 >= pspack * 9)
106 return pspack > 2 ? AVPROBE_SCORE_EXTENSION + 2
107 : AVPROBE_SCORE_EXTENSION / 2; // 1 more than .mpg
108 if ((!!vid ^ !!audio) && (audio > 4 || vid > 1) && !sys &&
109 !pspack && p->buf_size > 2048 && vid + audio > invalid) /* PES stream */
110 return (audio > 12 || vid > 3 + 2 * invalid) ? AVPROBE_SCORE_EXTENSION + 2
111 : AVPROBE_SCORE_EXTENSION / 2;
112
113 // 02-Penguin.flac has sys:0 priv1:0 pspack:0 vid:0 audio:1
114 // mp3_misidentified_2.mp3 has sys:0 priv1:0 pspack:0 vid:0 audio:6
115 // Have\ Yourself\ a\ Merry\ Little\ Christmas.mp3 0 0 0 5 0 1 len:21618
116 return score;
117 }
118
119 typedef struct MpegDemuxContext {
120 int32_t header_state;
121 unsigned char psm_es_type[256];
122 int sofdec;
123 int dvd;
124 int imkh_cctv;
125 #if CONFIG_VOBSUB_DEMUXER
126 AVFormatContext *sub_ctx;
127 FFDemuxSubtitlesQueue q[32];
128 #endif
129 } MpegDemuxContext;
130
mpegps_read_header(AVFormatContext * s)131 static int mpegps_read_header(AVFormatContext *s)
132 {
133 MpegDemuxContext *m = s->priv_data;
134 char buffer[7];
135 int64_t last_pos = avio_tell(s->pb);
136
137 m->header_state = 0xff;
138 s->ctx_flags |= AVFMTCTX_NOHEADER;
139
140 avio_get_str(s->pb, 6, buffer, sizeof(buffer));
141 if (!memcmp("IMKH", buffer, 4)) {
142 m->imkh_cctv = 1;
143 } else if (!memcmp("Sofdec", buffer, 6)) {
144 m->sofdec = 1;
145 } else
146 avio_seek(s->pb, last_pos, SEEK_SET);
147
148 /* no need to do more */
149 return 0;
150 }
151
get_pts(AVIOContext * pb,int c)152 static int64_t get_pts(AVIOContext *pb, int c)
153 {
154 uint8_t buf[5];
155
156 buf[0] = c < 0 ? avio_r8(pb) : c;
157 avio_read(pb, buf + 1, 4);
158
159 return ff_parse_pes_pts(buf);
160 }
161
find_next_start_code(AVIOContext * pb,int * size_ptr,int32_t * header_state)162 static int find_next_start_code(AVIOContext *pb, int *size_ptr,
163 int32_t *header_state)
164 {
165 unsigned int state, v;
166 int val, n;
167
168 state = *header_state;
169 n = *size_ptr;
170 while (n > 0) {
171 if (avio_feof(pb))
172 break;
173 v = avio_r8(pb);
174 n--;
175 if (state == 0x000001) {
176 state = ((state << 8) | v) & 0xffffff;
177 val = state;
178 goto found;
179 }
180 state = ((state << 8) | v) & 0xffffff;
181 }
182 val = -1;
183
184 found:
185 *header_state = state;
186 *size_ptr = n;
187 return val;
188 }
189
190 /**
191 * Extract stream types from a program stream map
192 * According to ISO/IEC 13818-1 ('MPEG-2 Systems') table 2-35
193 *
194 * @return number of bytes occupied by PSM in the bitstream
195 */
mpegps_psm_parse(MpegDemuxContext * m,AVIOContext * pb)196 static long mpegps_psm_parse(MpegDemuxContext *m, AVIOContext *pb)
197 {
198 int psm_length, ps_info_length, es_map_length;
199
200 psm_length = avio_rb16(pb);
201 avio_r8(pb);
202 avio_r8(pb);
203 ps_info_length = avio_rb16(pb);
204
205 /* skip program_stream_info */
206 avio_skip(pb, ps_info_length);
207 es_map_length = avio_rb16(pb);
208 /* Ignore es_map_length, trust psm_length */
209 es_map_length = psm_length - ps_info_length - 10;
210
211 /* at least one es available? */
212 while (es_map_length >= 4) {
213 unsigned char type = avio_r8(pb);
214 unsigned char es_id = avio_r8(pb);
215 uint16_t es_info_length = avio_rb16(pb);
216
217 /* remember mapping from stream id to stream type */
218 m->psm_es_type[es_id] = type;
219 /* skip program_stream_info */
220 avio_skip(pb, es_info_length);
221 es_map_length -= 4 + es_info_length;
222 }
223 avio_rb32(pb); /* crc32 */
224 return 2 + psm_length;
225 }
226
227 /* read the next PES header. Return its position in ppos
228 * (if not NULL), and its start code, pts and dts.
229 */
mpegps_read_pes_header(AVFormatContext * s,int64_t * ppos,int * pstart_code,int64_t * ppts,int64_t * pdts)230 static int mpegps_read_pes_header(AVFormatContext *s,
231 int64_t *ppos, int *pstart_code,
232 int64_t *ppts, int64_t *pdts)
233 {
234 MpegDemuxContext *m = s->priv_data;
235 int len, size, startcode, c, flags, header_len;
236 int pes_ext, ext2_len, id_ext, skip;
237 int64_t pts, dts;
238 int64_t last_sync = avio_tell(s->pb);
239
240 error_redo:
241 avio_seek(s->pb, last_sync, SEEK_SET);
242 redo:
243 /* next start code (should be immediately after) */
244 m->header_state = 0xff;
245 size = MAX_SYNC_SIZE;
246 startcode = find_next_start_code(s->pb, &size, &m->header_state);
247 last_sync = avio_tell(s->pb);
248 if (startcode < 0) {
249 if (avio_feof(s->pb))
250 return AVERROR_EOF;
251 // FIXME we should remember header_state
252 return AVERROR(EAGAIN);
253 }
254
255 if (startcode == PACK_START_CODE)
256 goto redo;
257 if (startcode == SYSTEM_HEADER_START_CODE)
258 goto redo;
259 if (startcode == PADDING_STREAM) {
260 avio_skip(s->pb, avio_rb16(s->pb));
261 goto redo;
262 }
263 if (startcode == PRIVATE_STREAM_2) {
264 if (!m->sofdec) {
265 /* Need to detect whether this from a DVD or a 'Sofdec' stream */
266 int len = avio_rb16(s->pb);
267 int bytesread = 0;
268 uint8_t *ps2buf = av_malloc(len);
269
270 if (ps2buf) {
271 bytesread = avio_read(s->pb, ps2buf, len);
272
273 if (bytesread != len) {
274 avio_skip(s->pb, len - bytesread);
275 } else {
276 uint8_t *p = 0;
277 if (len >= 6)
278 p = memchr(ps2buf, 'S', len - 5);
279
280 if (p)
281 m->sofdec = !memcmp(p+1, "ofdec", 5);
282
283 m->sofdec -= !m->sofdec;
284
285 if (m->sofdec < 0) {
286 if (len == 980 && ps2buf[0] == 0) {
287 /* PCI structure? */
288 uint32_t startpts = AV_RB32(ps2buf + 0x0d);
289 uint32_t endpts = AV_RB32(ps2buf + 0x11);
290 uint8_t hours = ((ps2buf[0x19] >> 4) * 10) + (ps2buf[0x19] & 0x0f);
291 uint8_t mins = ((ps2buf[0x1a] >> 4) * 10) + (ps2buf[0x1a] & 0x0f);
292 uint8_t secs = ((ps2buf[0x1b] >> 4) * 10) + (ps2buf[0x1b] & 0x0f);
293
294 m->dvd = (hours <= 23 &&
295 mins <= 59 &&
296 secs <= 59 &&
297 (ps2buf[0x19] & 0x0f) < 10 &&
298 (ps2buf[0x1a] & 0x0f) < 10 &&
299 (ps2buf[0x1b] & 0x0f) < 10 &&
300 endpts >= startpts);
301 } else if (len == 1018 && ps2buf[0] == 1) {
302 /* DSI structure? */
303 uint8_t hours = ((ps2buf[0x1d] >> 4) * 10) + (ps2buf[0x1d] & 0x0f);
304 uint8_t mins = ((ps2buf[0x1e] >> 4) * 10) + (ps2buf[0x1e] & 0x0f);
305 uint8_t secs = ((ps2buf[0x1f] >> 4) * 10) + (ps2buf[0x1f] & 0x0f);
306
307 m->dvd = (hours <= 23 &&
308 mins <= 59 &&
309 secs <= 59 &&
310 (ps2buf[0x1d] & 0x0f) < 10 &&
311 (ps2buf[0x1e] & 0x0f) < 10 &&
312 (ps2buf[0x1f] & 0x0f) < 10);
313 }
314 }
315 }
316
317 av_free(ps2buf);
318
319 /* If this isn't a DVD packet or no memory
320 * could be allocated, just ignore it.
321 * If we did, move back to the start of the
322 * packet (plus 'length' field) */
323 if (!m->dvd || avio_skip(s->pb, -(len + 2)) < 0) {
324 /* Skip back failed.
325 * This packet will be lost but that can't be helped
326 * if we can't skip back
327 */
328 goto redo;
329 }
330 } else {
331 /* No memory */
332 avio_skip(s->pb, len);
333 goto redo;
334 }
335 } else if (!m->dvd) {
336 int len = avio_rb16(s->pb);
337 avio_skip(s->pb, len);
338 goto redo;
339 }
340 }
341 if (startcode == PROGRAM_STREAM_MAP) {
342 mpegps_psm_parse(m, s->pb);
343 goto redo;
344 }
345
346 /* find matching stream */
347 if (!((startcode >= 0x1c0 && startcode <= 0x1df) ||
348 (startcode >= 0x1e0 && startcode <= 0x1ef) ||
349 (startcode == 0x1bd) ||
350 (startcode == PRIVATE_STREAM_2) ||
351 (startcode == 0x1fd)))
352 goto redo;
353 if (ppos) {
354 *ppos = avio_tell(s->pb) - 4;
355 }
356 len = avio_rb16(s->pb);
357 pts =
358 dts = AV_NOPTS_VALUE;
359 if (startcode != PRIVATE_STREAM_2)
360 {
361 /* stuffing */
362 for (;;) {
363 if (len < 1)
364 goto error_redo;
365 c = avio_r8(s->pb);
366 len--;
367 /* XXX: for mpeg1, should test only bit 7 */
368 if (c != 0xff)
369 break;
370 }
371 if ((c & 0xc0) == 0x40) {
372 /* buffer scale & size */
373 avio_r8(s->pb);
374 c = avio_r8(s->pb);
375 len -= 2;
376 }
377 if ((c & 0xe0) == 0x20) {
378 dts =
379 pts = get_pts(s->pb, c);
380 len -= 4;
381 if (c & 0x10) {
382 dts = get_pts(s->pb, -1);
383 len -= 5;
384 }
385 } else if ((c & 0xc0) == 0x80) {
386 /* mpeg 2 PES */
387 flags = avio_r8(s->pb);
388 header_len = avio_r8(s->pb);
389 len -= 2;
390 if (header_len > len)
391 goto error_redo;
392 len -= header_len;
393 if (flags & 0x80) {
394 dts = pts = get_pts(s->pb, -1);
395 header_len -= 5;
396 if (flags & 0x40) {
397 dts = get_pts(s->pb, -1);
398 header_len -= 5;
399 }
400 }
401 if (flags & 0x3f && header_len == 0) {
402 flags &= 0xC0;
403 av_log(s, AV_LOG_WARNING, "Further flags set but no bytes left\n");
404 }
405 if (flags & 0x01) { /* PES extension */
406 pes_ext = avio_r8(s->pb);
407 header_len--;
408 /* Skip PES private data, program packet sequence counter
409 * and P-STD buffer */
410 skip = (pes_ext >> 4) & 0xb;
411 skip += skip & 0x9;
412 if (pes_ext & 0x40 || skip > header_len) {
413 av_log(s, AV_LOG_WARNING, "pes_ext %X is invalid\n", pes_ext);
414 pes_ext = skip = 0;
415 }
416 avio_skip(s->pb, skip);
417 header_len -= skip;
418
419 if (pes_ext & 0x01) { /* PES extension 2 */
420 ext2_len = avio_r8(s->pb);
421 header_len--;
422 if ((ext2_len & 0x7f) > 0) {
423 id_ext = avio_r8(s->pb);
424 if ((id_ext & 0x80) == 0)
425 startcode = ((startcode & 0xff) << 8) | id_ext;
426 header_len--;
427 }
428 }
429 }
430 if (header_len < 0)
431 goto error_redo;
432 avio_skip(s->pb, header_len);
433 } else if (c != 0xf)
434 goto redo;
435 }
436
437 if (startcode == PRIVATE_STREAM_1) {
438 startcode = avio_r8(s->pb);
439 len--;
440 }
441 if (len < 0)
442 goto error_redo;
443 if (dts != AV_NOPTS_VALUE && ppos) {
444 int i;
445 for (i = 0; i < s->nb_streams; i++) {
446 if (startcode == s->streams[i]->id &&
447 s->pb->seekable /* index useless on streams anyway */) {
448 ff_reduce_index(s, i);
449 av_add_index_entry(s->streams[i], *ppos, dts, 0, 0,
450 AVINDEX_KEYFRAME /* FIXME keyframe? */);
451 }
452 }
453 }
454
455 *pstart_code = startcode;
456 *ppts = pts;
457 *pdts = dts;
458 return len;
459 }
460
mpegps_read_packet(AVFormatContext * s,AVPacket * pkt)461 static int mpegps_read_packet(AVFormatContext *s,
462 AVPacket *pkt)
463 {
464 MpegDemuxContext *m = s->priv_data;
465 AVStream *st;
466 int len, startcode, i, es_type, ret;
467 int lpcm_header_len = -1; //Init to suppress warning
468 int request_probe= 0;
469 enum AVCodecID codec_id = AV_CODEC_ID_NONE;
470 enum AVMediaType type;
471 int64_t pts, dts, dummy_pos; // dummy_pos is needed for the index building to work
472
473 redo:
474 len = mpegps_read_pes_header(s, &dummy_pos, &startcode, &pts, &dts);
475 if (len < 0)
476 return len;
477
478 if (startcode >= 0x80 && startcode <= 0xcf) {
479 if (len < 4)
480 goto skip;
481
482 /* audio: skip header */
483 avio_r8(s->pb);
484 lpcm_header_len = avio_rb16(s->pb);
485 len -= 3;
486 if (startcode >= 0xb0 && startcode <= 0xbf) {
487 /* MLP/TrueHD audio has a 4-byte header */
488 avio_r8(s->pb);
489 len--;
490 }
491 }
492
493 /* now find stream */
494 for (i = 0; i < s->nb_streams; i++) {
495 st = s->streams[i];
496 if (st->id == startcode)
497 goto found;
498 }
499
500 es_type = m->psm_es_type[startcode & 0xff];
501 if (es_type == STREAM_TYPE_VIDEO_MPEG1) {
502 codec_id = AV_CODEC_ID_MPEG2VIDEO;
503 type = AVMEDIA_TYPE_VIDEO;
504 } else if (es_type == STREAM_TYPE_VIDEO_MPEG2) {
505 codec_id = AV_CODEC_ID_MPEG2VIDEO;
506 type = AVMEDIA_TYPE_VIDEO;
507 } else if (es_type == STREAM_TYPE_AUDIO_MPEG1 ||
508 es_type == STREAM_TYPE_AUDIO_MPEG2) {
509 codec_id = AV_CODEC_ID_MP3;
510 type = AVMEDIA_TYPE_AUDIO;
511 } else if (es_type == STREAM_TYPE_AUDIO_AAC) {
512 codec_id = AV_CODEC_ID_AAC;
513 type = AVMEDIA_TYPE_AUDIO;
514 } else if (es_type == STREAM_TYPE_VIDEO_MPEG4) {
515 codec_id = AV_CODEC_ID_MPEG4;
516 type = AVMEDIA_TYPE_VIDEO;
517 } else if (es_type == STREAM_TYPE_VIDEO_H264) {
518 codec_id = AV_CODEC_ID_H264;
519 type = AVMEDIA_TYPE_VIDEO;
520 } else if (es_type == STREAM_TYPE_AUDIO_AC3) {
521 codec_id = AV_CODEC_ID_AC3;
522 type = AVMEDIA_TYPE_AUDIO;
523 } else if (m->imkh_cctv && es_type == 0x91) {
524 codec_id = AV_CODEC_ID_PCM_MULAW;
525 type = AVMEDIA_TYPE_AUDIO;
526 } else if (startcode >= 0x1e0 && startcode <= 0x1ef) {
527 static const unsigned char avs_seqh[4] = { 0, 0, 1, 0xb0 };
528 unsigned char buf[8];
529
530 avio_read(s->pb, buf, 8);
531 avio_seek(s->pb, -8, SEEK_CUR);
532 if (!memcmp(buf, avs_seqh, 4) && (buf[6] != 0 || buf[7] != 1))
533 codec_id = AV_CODEC_ID_CAVS;
534 else
535 request_probe= 1;
536 type = AVMEDIA_TYPE_VIDEO;
537 } else if (startcode == PRIVATE_STREAM_2) {
538 type = AVMEDIA_TYPE_DATA;
539 codec_id = AV_CODEC_ID_DVD_NAV;
540 } else if (startcode >= 0x1c0 && startcode <= 0x1df) {
541 type = AVMEDIA_TYPE_AUDIO;
542 if (m->sofdec > 0) {
543 codec_id = AV_CODEC_ID_ADPCM_ADX;
544 // Auto-detect AC-3
545 request_probe = 50;
546 } else {
547 codec_id = AV_CODEC_ID_MP2;
548 }
549 } else if (startcode >= 0x80 && startcode <= 0x87) {
550 type = AVMEDIA_TYPE_AUDIO;
551 codec_id = AV_CODEC_ID_AC3;
552 } else if ((startcode >= 0x88 && startcode <= 0x8f) ||
553 (startcode >= 0x98 && startcode <= 0x9f)) {
554 /* 0x90 - 0x97 is reserved for SDDS in DVD specs */
555 type = AVMEDIA_TYPE_AUDIO;
556 codec_id = AV_CODEC_ID_DTS;
557 } else if (startcode >= 0xa0 && startcode <= 0xaf) {
558 type = AVMEDIA_TYPE_AUDIO;
559 if (lpcm_header_len == 6) {
560 codec_id = AV_CODEC_ID_MLP;
561 } else {
562 codec_id = AV_CODEC_ID_PCM_DVD;
563 }
564 } else if (startcode >= 0xb0 && startcode <= 0xbf) {
565 type = AVMEDIA_TYPE_AUDIO;
566 codec_id = AV_CODEC_ID_TRUEHD;
567 } else if (startcode >= 0xc0 && startcode <= 0xcf) {
568 /* Used for both AC-3 and E-AC-3 in EVOB files */
569 type = AVMEDIA_TYPE_AUDIO;
570 codec_id = AV_CODEC_ID_AC3;
571 } else if (startcode >= 0x20 && startcode <= 0x3f) {
572 type = AVMEDIA_TYPE_SUBTITLE;
573 codec_id = AV_CODEC_ID_DVD_SUBTITLE;
574 } else if (startcode >= 0xfd55 && startcode <= 0xfd5f) {
575 type = AVMEDIA_TYPE_VIDEO;
576 codec_id = AV_CODEC_ID_VC1;
577 } else {
578 skip:
579 /* skip packet */
580 avio_skip(s->pb, len);
581 goto redo;
582 }
583 /* no stream found: add a new stream */
584 st = avformat_new_stream(s, NULL);
585 if (!st)
586 goto skip;
587 st->id = startcode;
588 st->codec->codec_type = type;
589 st->codec->codec_id = codec_id;
590 if (st->codec->codec_id == AV_CODEC_ID_PCM_MULAW) {
591 st->codec->channels = 1;
592 st->codec->channel_layout = AV_CH_LAYOUT_MONO;
593 st->codec->sample_rate = 8000;
594 }
595 st->request_probe = request_probe;
596 st->need_parsing = AVSTREAM_PARSE_FULL;
597
598 found:
599 if (st->discard >= AVDISCARD_ALL)
600 goto skip;
601 if (startcode >= 0xa0 && startcode <= 0xaf) {
602 if (lpcm_header_len == 6 && st->codec->codec_id == AV_CODEC_ID_MLP) {
603 if (len < 6)
604 goto skip;
605 avio_skip(s->pb, 6);
606 len -=6;
607 }
608 }
609 ret = av_get_packet(s->pb, pkt, len);
610
611 pkt->pts = pts;
612 pkt->dts = dts;
613 pkt->pos = dummy_pos;
614 pkt->stream_index = st->index;
615 av_dlog(s, "%d: pts=%0.3f dts=%0.3f size=%d\n",
616 pkt->stream_index, pkt->pts / 90000.0, pkt->dts / 90000.0,
617 pkt->size);
618
619 return (ret < 0) ? ret : 0;
620 }
621
mpegps_read_dts(AVFormatContext * s,int stream_index,int64_t * ppos,int64_t pos_limit)622 static int64_t mpegps_read_dts(AVFormatContext *s, int stream_index,
623 int64_t *ppos, int64_t pos_limit)
624 {
625 int len, startcode;
626 int64_t pos, pts, dts;
627
628 pos = *ppos;
629 if (avio_seek(s->pb, pos, SEEK_SET) < 0)
630 return AV_NOPTS_VALUE;
631
632 for (;;) {
633 len = mpegps_read_pes_header(s, &pos, &startcode, &pts, &dts);
634 if (len < 0) {
635 av_dlog(s, "none (ret=%d)\n", len);
636 return AV_NOPTS_VALUE;
637 }
638 if (startcode == s->streams[stream_index]->id &&
639 dts != AV_NOPTS_VALUE) {
640 break;
641 }
642 avio_skip(s->pb, len);
643 }
644 av_dlog(s, "pos=0x%"PRIx64" dts=0x%"PRIx64" %0.3f\n",
645 pos, dts, dts / 90000.0);
646 *ppos = pos;
647 return dts;
648 }
649
650 AVInputFormat ff_mpegps_demuxer = {
651 .name = "mpeg",
652 .long_name = NULL_IF_CONFIG_SMALL("MPEG-PS (MPEG-2 Program Stream)"),
653 .priv_data_size = sizeof(MpegDemuxContext),
654 .read_probe = mpegps_probe,
655 .read_header = mpegps_read_header,
656 .read_packet = mpegps_read_packet,
657 .read_timestamp = mpegps_read_dts,
658 .flags = AVFMT_SHOW_IDS | AVFMT_TS_DISCONT,
659 };
660
661 #if CONFIG_VOBSUB_DEMUXER
662
663 #define REF_STRING "# VobSub index file,"
664 #define MAX_LINE_SIZE 2048
665
vobsub_probe(AVProbeData * p)666 static int vobsub_probe(AVProbeData *p)
667 {
668 if (!strncmp(p->buf, REF_STRING, sizeof(REF_STRING) - 1))
669 return AVPROBE_SCORE_MAX;
670 return 0;
671 }
672
vobsub_read_header(AVFormatContext * s)673 static int vobsub_read_header(AVFormatContext *s)
674 {
675 int i, ret = 0, header_parsed = 0, langidx = 0;
676 MpegDemuxContext *vobsub = s->priv_data;
677 char *sub_name = NULL;
678 size_t fname_len;
679 char *ext, *header_str;
680 AVBPrint header;
681 int64_t delay = 0;
682 AVStream *st = NULL;
683 int stream_id = -1;
684 char id[64] = {0};
685 char alt[MAX_LINE_SIZE] = {0};
686
687 sub_name = av_strdup(s->filename);
688 fname_len = strlen(sub_name);
689 ext = sub_name - 3 + fname_len;
690 if (fname_len < 4 || *(ext - 1) != '.') {
691 av_log(s, AV_LOG_ERROR, "The input index filename is too short "
692 "to guess the associated .SUB file\n");
693 ret = AVERROR_INVALIDDATA;
694 goto end;
695 }
696 memcpy(ext, !strncmp(ext, "IDX", 3) ? "SUB" : "sub", 3);
697 av_log(s, AV_LOG_VERBOSE, "IDX/SUB: %s -> %s\n", s->filename, sub_name);
698 ret = avformat_open_input(&vobsub->sub_ctx, sub_name, &ff_mpegps_demuxer, NULL);
699 if (ret < 0) {
700 av_log(s, AV_LOG_ERROR, "Unable to open %s as MPEG subtitles\n", sub_name);
701 goto end;
702 }
703
704 av_bprint_init(&header, 0, AV_BPRINT_SIZE_UNLIMITED);
705 while (!avio_feof(s->pb)) {
706 char line[MAX_LINE_SIZE];
707 int len = ff_get_line(s->pb, line, sizeof(line));
708
709 if (!len)
710 break;
711
712 line[strcspn(line, "\r\n")] = 0;
713
714 if (!strncmp(line, "id:", 3)) {
715 if (sscanf(line, "id: %63[^,], index: %u", id, &stream_id) != 2) {
716 av_log(s, AV_LOG_WARNING, "Unable to parse index line '%s', "
717 "assuming 'id: und, index: 0'\n", line);
718 strcpy(id, "und");
719 stream_id = 0;
720 }
721
722 if (stream_id >= FF_ARRAY_ELEMS(vobsub->q)) {
723 av_log(s, AV_LOG_ERROR, "Maximum number of subtitles streams reached\n");
724 ret = AVERROR(EINVAL);
725 goto end;
726 }
727
728 header_parsed = 1;
729 alt[0] = '\0';
730 /* We do not create the stream immediately to avoid adding empty
731 * streams. See the following timestamp entry. */
732
733 av_log(s, AV_LOG_DEBUG, "IDX stream[%d] id=%s\n", stream_id, id);
734
735 } else if (!strncmp(line, "timestamp:", 10)) {
736 AVPacket *sub;
737 int hh, mm, ss, ms;
738 int64_t pos, timestamp;
739 const char *p = line + 10;
740
741 if (stream_id == -1) {
742 av_log(s, AV_LOG_ERROR, "Timestamp declared before any stream\n");
743 ret = AVERROR_INVALIDDATA;
744 goto end;
745 }
746
747 if (!st || st->id != stream_id) {
748 st = avformat_new_stream(s, NULL);
749 if (!st) {
750 ret = AVERROR(ENOMEM);
751 goto end;
752 }
753 st->id = stream_id;
754 st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
755 st->codec->codec_id = AV_CODEC_ID_DVD_SUBTITLE;
756 avpriv_set_pts_info(st, 64, 1, 1000);
757 av_dict_set(&st->metadata, "language", id, 0);
758 if (alt[0])
759 av_dict_set(&st->metadata, "title", alt, 0);
760 }
761
762 if (sscanf(p, "%02d:%02d:%02d:%03d, filepos: %"SCNx64,
763 &hh, &mm, &ss, &ms, &pos) != 5) {
764 av_log(s, AV_LOG_ERROR, "Unable to parse timestamp line '%s', "
765 "abort parsing\n", line);
766 ret = AVERROR_INVALIDDATA;
767 goto end;
768 }
769 timestamp = (hh*LLN(3600) + mm*LLN(60) + ss) * LLN(1000) + ms + delay;
770 timestamp = av_rescale_q(timestamp, av_make_q(1, 1000), st->time_base);
771
772 sub = ff_subtitles_queue_insert(&vobsub->q[s->nb_streams - 1], "", 0, 0);
773 if (!sub) {
774 ret = AVERROR(ENOMEM);
775 goto end;
776 }
777 sub->pos = pos;
778 sub->pts = timestamp;
779 sub->stream_index = s->nb_streams - 1;
780
781 } else if (!strncmp(line, "alt:", 4)) {
782 const char *p = line + 4;
783
784 while (*p == ' ')
785 p++;
786 av_log(s, AV_LOG_DEBUG, "IDX stream[%d] name=%s\n", stream_id, p);
787 av_strlcpy(alt, p, sizeof(alt));
788 header_parsed = 1;
789
790 } else if (!strncmp(line, "delay:", 6)) {
791 int sign = 1, hh = 0, mm = 0, ss = 0, ms = 0;
792 const char *p = line + 6;
793
794 while (*p == ' ')
795 p++;
796 if (*p == '-' || *p == '+') {
797 sign = *p == '-' ? -1 : 1;
798 p++;
799 }
800 sscanf(p, "%d:%d:%d:%d", &hh, &mm, &ss, &ms);
801 delay = ((hh*LLN(3600) + mm*LLN(60) + ss) * LLN(1000) + ms) * sign;
802
803 } else if (!strncmp(line, "langidx:", 8)) {
804 const char *p = line + 8;
805
806 if (sscanf(p, "%d", &langidx) != 1)
807 av_log(s, AV_LOG_ERROR, "Invalid langidx specified\n");
808
809 } else if (!header_parsed) {
810 if (line[0] && line[0] != '#')
811 av_bprintf(&header, "%s\n", line);
812 }
813 }
814
815 if (langidx < s->nb_streams)
816 s->streams[langidx]->disposition |= AV_DISPOSITION_DEFAULT;
817
818 for (i = 0; i < s->nb_streams; i++) {
819 vobsub->q[i].sort = SUB_SORT_POS_TS;
820 ff_subtitles_queue_finalize(&vobsub->q[i]);
821 }
822
823 if (!av_bprint_is_complete(&header)) {
824 av_bprint_finalize(&header, NULL);
825 ret = AVERROR(ENOMEM);
826 goto end;
827 }
828 av_bprint_finalize(&header, &header_str);
829 for (i = 0; i < s->nb_streams; i++) {
830 AVStream *sub_st = s->streams[i];
831 sub_st->codec->extradata = av_strdup(header_str);
832 sub_st->codec->extradata_size = header.len;
833 }
834 av_free(header_str);
835
836 end:
837 av_free(sub_name);
838 return ret;
839 }
840
vobsub_read_packet(AVFormatContext * s,AVPacket * pkt)841 static int vobsub_read_packet(AVFormatContext *s, AVPacket *pkt)
842 {
843 MpegDemuxContext *vobsub = s->priv_data;
844 FFDemuxSubtitlesQueue *q;
845 AVIOContext *pb = vobsub->sub_ctx->pb;
846 int ret, psize, total_read = 0, i;
847 AVPacket idx_pkt;
848
849 int64_t min_ts = INT64_MAX;
850 int sid = 0;
851 for (i = 0; i < s->nb_streams; i++) {
852 FFDemuxSubtitlesQueue *tmpq = &vobsub->q[i];
853 int64_t ts;
854 av_assert0(tmpq->nb_subs);
855 ts = tmpq->subs[tmpq->current_sub_idx].pts;
856 if (ts < min_ts) {
857 min_ts = ts;
858 sid = i;
859 }
860 }
861 q = &vobsub->q[sid];
862 ret = ff_subtitles_queue_read_packet(q, &idx_pkt);
863 if (ret < 0)
864 return ret;
865
866 /* compute maximum packet size using the next packet position. This is
867 * useful when the len in the header is non-sense */
868 if (q->current_sub_idx < q->nb_subs) {
869 psize = q->subs[q->current_sub_idx].pos - idx_pkt.pos;
870 } else {
871 int64_t fsize = avio_size(pb);
872 psize = fsize < 0 ? 0xffff : fsize - idx_pkt.pos;
873 }
874
875 avio_seek(pb, idx_pkt.pos, SEEK_SET);
876
877 av_init_packet(pkt);
878 pkt->size = 0;
879 pkt->data = NULL;
880
881 do {
882 int n, to_read, startcode;
883 int64_t pts, dts;
884 int64_t old_pos = avio_tell(pb), new_pos;
885 int pkt_size;
886
887 ret = mpegps_read_pes_header(vobsub->sub_ctx, NULL, &startcode, &pts, &dts);
888 if (ret < 0) {
889 if (pkt->size) // raise packet even if incomplete
890 break;
891 goto fail;
892 }
893 to_read = ret & 0xffff;
894 new_pos = avio_tell(pb);
895 pkt_size = ret + (new_pos - old_pos);
896
897 /* this prevents reads above the current packet */
898 if (total_read + pkt_size > psize)
899 break;
900 total_read += pkt_size;
901
902 /* the current chunk doesn't match the stream index (unlikely) */
903 if ((startcode & 0x1f) != idx_pkt.stream_index)
904 break;
905
906 ret = av_grow_packet(pkt, to_read);
907 if (ret < 0)
908 goto fail;
909
910 n = avio_read(pb, pkt->data + (pkt->size - to_read), to_read);
911 if (n < to_read)
912 pkt->size -= to_read - n;
913 } while (total_read < psize);
914
915 pkt->pts = pkt->dts = idx_pkt.pts;
916 pkt->pos = idx_pkt.pos;
917 pkt->stream_index = idx_pkt.stream_index;
918
919 av_free_packet(&idx_pkt);
920 return 0;
921
922 fail:
923 av_free_packet(pkt);
924 av_free_packet(&idx_pkt);
925 return ret;
926 }
927
vobsub_read_seek(AVFormatContext * s,int stream_index,int64_t min_ts,int64_t ts,int64_t max_ts,int flags)928 static int vobsub_read_seek(AVFormatContext *s, int stream_index,
929 int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
930 {
931 MpegDemuxContext *vobsub = s->priv_data;
932
933 /* Rescale requested timestamps based on the first stream (timebase is the
934 * same for all subtitles stream within a .idx/.sub). Rescaling is done just
935 * like in avformat_seek_file(). */
936 if (stream_index == -1 && s->nb_streams != 1) {
937 int i, ret = 0;
938 AVRational time_base = s->streams[0]->time_base;
939 ts = av_rescale_q(ts, AV_TIME_BASE_Q, time_base);
940 min_ts = av_rescale_rnd(min_ts, time_base.den,
941 time_base.num * (int64_t)AV_TIME_BASE,
942 AV_ROUND_UP | AV_ROUND_PASS_MINMAX);
943 max_ts = av_rescale_rnd(max_ts, time_base.den,
944 time_base.num * (int64_t)AV_TIME_BASE,
945 AV_ROUND_DOWN | AV_ROUND_PASS_MINMAX);
946 for (i = 0; i < s->nb_streams; i++) {
947 int r = ff_subtitles_queue_seek(&vobsub->q[i], s, stream_index,
948 min_ts, ts, max_ts, flags);
949 if (r < 0)
950 ret = r;
951 }
952 return ret;
953 }
954
955 if (stream_index == -1) // only 1 stream
956 stream_index = 0;
957 return ff_subtitles_queue_seek(&vobsub->q[stream_index], s, stream_index,
958 min_ts, ts, max_ts, flags);
959 }
960
vobsub_read_close(AVFormatContext * s)961 static int vobsub_read_close(AVFormatContext *s)
962 {
963 int i;
964 MpegDemuxContext *vobsub = s->priv_data;
965
966 for (i = 0; i < s->nb_streams; i++)
967 ff_subtitles_queue_clean(&vobsub->q[i]);
968 if (vobsub->sub_ctx)
969 avformat_close_input(&vobsub->sub_ctx);
970 return 0;
971 }
972
973 AVInputFormat ff_vobsub_demuxer = {
974 .name = "vobsub",
975 .long_name = NULL_IF_CONFIG_SMALL("VobSub subtitle format"),
976 .priv_data_size = sizeof(MpegDemuxContext),
977 .read_probe = vobsub_probe,
978 .read_header = vobsub_read_header,
979 .read_packet = vobsub_read_packet,
980 .read_seek2 = vobsub_read_seek,
981 .read_close = vobsub_read_close,
982 .flags = AVFMT_SHOW_IDS,
983 .extensions = "idx",
984 };
985 #endif
986