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mpeg.c
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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 
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 
62 static int check_pack_header(const uint8_t *buf)
63 {
64  return (buf[1] & 0xC0) == 0x40 || (buf[1] & 0xF0) == 0x20;
65 }
66 
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  int endpes = 0;
74 
75  for (i = 0; i < p->buf_size; i++) {
76  code = (code << 8) + p->buf[i];
77  if ((code & 0xffffff00) == 0x100) {
78  int len = p->buf[i + 1] << 8 | p->buf[i + 2];
79  int pes = endpes <= i && check_pes(p->buf + i, p->buf + p->buf_size);
80  int pack = check_pack_header(p->buf + i);
81 
82  if (code == SYSTEM_HEADER_START_CODE)
83  sys++;
84  else if (code == PACK_START_CODE && pack)
85  pspack++;
86  else if ((code & 0xf0) == VIDEO_ID && pes) {
87  endpes = i + len;
88  vid++;
89  }
90  // skip pes payload to avoid start code emulation for private
91  // and audio streams
92  else if ((code & 0xe0) == AUDIO_ID && pes) {audio++; i+=len;}
93  else if (code == PRIVATE_STREAM_1 && pes) {priv1++; i+=len;}
94  else if (code == 0x1fd && pes) vid++; //VC1
95 
96  else if ((code & 0xf0) == VIDEO_ID && !pes) invalid++;
97  else if ((code & 0xe0) == AUDIO_ID && !pes) invalid++;
98  else if (code == PRIVATE_STREAM_1 && !pes) invalid++;
99  }
100  }
101 
102  if (vid + audio > invalid + 1) /* invalid VDR files nd short PES streams */
103  score = AVPROBE_SCORE_EXTENSION / 2;
104 
105 // av_log(NULL, AV_LOG_ERROR, "vid:%d aud:%d sys:%d pspack:%d invalid:%d size:%d \n",
106 // vid, audio, sys, pspack, invalid, p->buf_size);
107 
108  if (sys > invalid && sys * 9 <= pspack * 10)
109  return (audio > 12 || vid > 3 || pspack > 2) ? AVPROBE_SCORE_EXTENSION + 2
110  : AVPROBE_SCORE_EXTENSION / 2 + 1; // 1 more than mp3
111  if (pspack > invalid && (priv1 + vid + audio) * 10 >= pspack * 9)
112  return pspack > 2 ? AVPROBE_SCORE_EXTENSION + 2
113  : AVPROBE_SCORE_EXTENSION / 2; // 1 more than .mpg
114  if ((!!vid ^ !!audio) && (audio > 4 || vid > 1) && !sys &&
115  !pspack && p->buf_size > 2048 && vid + audio > invalid) /* PES stream */
116  return (audio > 12 || vid > 3 + 2 * invalid) ? AVPROBE_SCORE_EXTENSION + 2
118 
119  // 02-Penguin.flac has sys:0 priv1:0 pspack:0 vid:0 audio:1
120  // mp3_misidentified_2.mp3 has sys:0 priv1:0 pspack:0 vid:0 audio:6
121  // Have\ Yourself\ a\ Merry\ Little\ Christmas.mp3 0 0 0 5 0 1 len:21618
122  return score;
123 }
124 
125 typedef struct MpegDemuxContext {
127  unsigned char psm_es_type[256];
128  int sofdec;
129  int dvd;
131 #if CONFIG_VOBSUB_DEMUXER
132  AVFormatContext *sub_ctx;
133  FFDemuxSubtitlesQueue q[32];
134 #endif
136 
138 {
140  char buffer[7];
141  int64_t last_pos = avio_tell(s->pb);
142 
143  m->header_state = 0xff;
145 
146  avio_get_str(s->pb, 6, buffer, sizeof(buffer));
147  if (!memcmp("IMKH", buffer, 4)) {
148  m->imkh_cctv = 1;
149  } else if (!memcmp("Sofdec", buffer, 6)) {
150  m->sofdec = 1;
151  } else
152  avio_seek(s->pb, last_pos, SEEK_SET);
153 
154  /* no need to do more */
155  return 0;
156 }
157 
158 static int64_t get_pts(AVIOContext *pb, int c)
159 {
160  uint8_t buf[5];
161 
162  buf[0] = c < 0 ? avio_r8(pb) : c;
163  avio_read(pb, buf + 1, 4);
164 
165  return ff_parse_pes_pts(buf);
166 }
167 
168 static int find_next_start_code(AVIOContext *pb, int *size_ptr,
169  int32_t *header_state)
170 {
171  unsigned int state, v;
172  int val, n;
173 
174  state = *header_state;
175  n = *size_ptr;
176  while (n > 0) {
177  if (avio_feof(pb))
178  break;
179  v = avio_r8(pb);
180  n--;
181  if (state == 0x000001) {
182  state = ((state << 8) | v) & 0xffffff;
183  val = state;
184  goto found;
185  }
186  state = ((state << 8) | v) & 0xffffff;
187  }
188  val = -1;
189 
190 found:
191  *header_state = state;
192  *size_ptr = n;
193  return val;
194 }
195 
196 /**
197  * Extract stream types from a program stream map
198  * According to ISO/IEC 13818-1 ('MPEG-2 Systems') table 2-35
199  *
200  * @return number of bytes occupied by PSM in the bitstream
201  */
203 {
204  int psm_length, ps_info_length, es_map_length;
205 
206  psm_length = avio_rb16(pb);
207  avio_r8(pb);
208  avio_r8(pb);
209  ps_info_length = avio_rb16(pb);
210 
211  /* skip program_stream_info */
212  avio_skip(pb, ps_info_length);
213  es_map_length = avio_rb16(pb);
214  /* Ignore es_map_length, trust psm_length */
215  es_map_length = psm_length - ps_info_length - 10;
216 
217  /* at least one es available? */
218  while (es_map_length >= 4) {
219  unsigned char type = avio_r8(pb);
220  unsigned char es_id = avio_r8(pb);
221  uint16_t es_info_length = avio_rb16(pb);
222 
223  /* remember mapping from stream id to stream type */
224  m->psm_es_type[es_id] = type;
225  /* skip program_stream_info */
226  avio_skip(pb, es_info_length);
227  es_map_length -= 4 + es_info_length;
228  }
229  avio_rb32(pb); /* crc32 */
230  return 2 + psm_length;
231 }
232 
233 /* read the next PES header. Return its position in ppos
234  * (if not NULL), and its start code, pts and dts.
235  */
237  int64_t *ppos, int *pstart_code,
238  int64_t *ppts, int64_t *pdts)
239 {
241  int len, size, startcode, c, flags, header_len;
242  int pes_ext, ext2_len, id_ext, skip;
243  int64_t pts, dts;
244  int64_t last_sync = avio_tell(s->pb);
245 
246 error_redo:
247  avio_seek(s->pb, last_sync, SEEK_SET);
248 redo:
249  /* next start code (should be immediately after) */
250  m->header_state = 0xff;
251  size = MAX_SYNC_SIZE;
252  startcode = find_next_start_code(s->pb, &size, &m->header_state);
253  last_sync = avio_tell(s->pb);
254  if (startcode < 0) {
255  if (avio_feof(s->pb))
256  return AVERROR_EOF;
257  // FIXME we should remember header_state
258  return AVERROR(EAGAIN);
259  }
260 
261  if (startcode == PACK_START_CODE)
262  goto redo;
263  if (startcode == SYSTEM_HEADER_START_CODE)
264  goto redo;
265  if (startcode == PADDING_STREAM) {
266  avio_skip(s->pb, avio_rb16(s->pb));
267  goto redo;
268  }
269  if (startcode == PRIVATE_STREAM_2) {
270  if (!m->sofdec) {
271  /* Need to detect whether this from a DVD or a 'Sofdec' stream */
272  int len = avio_rb16(s->pb);
273  int bytesread = 0;
274  uint8_t *ps2buf = av_malloc(len);
275 
276  if (ps2buf) {
277  bytesread = avio_read(s->pb, ps2buf, len);
278 
279  if (bytesread != len) {
280  avio_skip(s->pb, len - bytesread);
281  } else {
282  uint8_t *p = 0;
283  if (len >= 6)
284  p = memchr(ps2buf, 'S', len - 5);
285 
286  if (p)
287  m->sofdec = !memcmp(p+1, "ofdec", 5);
288 
289  m->sofdec -= !m->sofdec;
290 
291  if (m->sofdec < 0) {
292  if (len == 980 && ps2buf[0] == 0) {
293  /* PCI structure? */
294  uint32_t startpts = AV_RB32(ps2buf + 0x0d);
295  uint32_t endpts = AV_RB32(ps2buf + 0x11);
296  uint8_t hours = ((ps2buf[0x19] >> 4) * 10) + (ps2buf[0x19] & 0x0f);
297  uint8_t mins = ((ps2buf[0x1a] >> 4) * 10) + (ps2buf[0x1a] & 0x0f);
298  uint8_t secs = ((ps2buf[0x1b] >> 4) * 10) + (ps2buf[0x1b] & 0x0f);
299 
300  m->dvd = (hours <= 23 &&
301  mins <= 59 &&
302  secs <= 59 &&
303  (ps2buf[0x19] & 0x0f) < 10 &&
304  (ps2buf[0x1a] & 0x0f) < 10 &&
305  (ps2buf[0x1b] & 0x0f) < 10 &&
306  endpts >= startpts);
307  } else if (len == 1018 && ps2buf[0] == 1) {
308  /* DSI structure? */
309  uint8_t hours = ((ps2buf[0x1d] >> 4) * 10) + (ps2buf[0x1d] & 0x0f);
310  uint8_t mins = ((ps2buf[0x1e] >> 4) * 10) + (ps2buf[0x1e] & 0x0f);
311  uint8_t secs = ((ps2buf[0x1f] >> 4) * 10) + (ps2buf[0x1f] & 0x0f);
312 
313  m->dvd = (hours <= 23 &&
314  mins <= 59 &&
315  secs <= 59 &&
316  (ps2buf[0x1d] & 0x0f) < 10 &&
317  (ps2buf[0x1e] & 0x0f) < 10 &&
318  (ps2buf[0x1f] & 0x0f) < 10);
319  }
320  }
321  }
322 
323  av_free(ps2buf);
324 
325  /* If this isn't a DVD packet or no memory
326  * could be allocated, just ignore it.
327  * If we did, move back to the start of the
328  * packet (plus 'length' field) */
329  if (!m->dvd || avio_skip(s->pb, -(len + 2)) < 0) {
330  /* Skip back failed.
331  * This packet will be lost but that can't be helped
332  * if we can't skip back
333  */
334  goto redo;
335  }
336  } else {
337  /* No memory */
338  avio_skip(s->pb, len);
339  goto redo;
340  }
341  } else if (!m->dvd) {
342  int len = avio_rb16(s->pb);
343  avio_skip(s->pb, len);
344  goto redo;
345  }
346  }
347  if (startcode == PROGRAM_STREAM_MAP) {
348  mpegps_psm_parse(m, s->pb);
349  goto redo;
350  }
351 
352  /* find matching stream */
353  if (!((startcode >= 0x1c0 && startcode <= 0x1df) ||
354  (startcode >= 0x1e0 && startcode <= 0x1ef) ||
355  (startcode == 0x1bd) ||
356  (startcode == PRIVATE_STREAM_2) ||
357  (startcode == 0x1fd)))
358  goto redo;
359  if (ppos) {
360  *ppos = avio_tell(s->pb) - 4;
361  }
362  len = avio_rb16(s->pb);
363  pts =
364  dts = AV_NOPTS_VALUE;
365  if (startcode != PRIVATE_STREAM_2)
366  {
367  /* stuffing */
368  for (;;) {
369  if (len < 1)
370  goto error_redo;
371  c = avio_r8(s->pb);
372  len--;
373  /* XXX: for mpeg1, should test only bit 7 */
374  if (c != 0xff)
375  break;
376  }
377  if ((c & 0xc0) == 0x40) {
378  /* buffer scale & size */
379  avio_r8(s->pb);
380  c = avio_r8(s->pb);
381  len -= 2;
382  }
383  if ((c & 0xe0) == 0x20) {
384  dts =
385  pts = get_pts(s->pb, c);
386  len -= 4;
387  if (c & 0x10) {
388  dts = get_pts(s->pb, -1);
389  len -= 5;
390  }
391  } else if ((c & 0xc0) == 0x80) {
392  /* mpeg 2 PES */
393  flags = avio_r8(s->pb);
394  header_len = avio_r8(s->pb);
395  len -= 2;
396  if (header_len > len)
397  goto error_redo;
398  len -= header_len;
399  if (flags & 0x80) {
400  dts = pts = get_pts(s->pb, -1);
401  header_len -= 5;
402  if (flags & 0x40) {
403  dts = get_pts(s->pb, -1);
404  header_len -= 5;
405  }
406  }
407  if (flags & 0x3f && header_len == 0) {
408  flags &= 0xC0;
409  av_log(s, AV_LOG_WARNING, "Further flags set but no bytes left\n");
410  }
411  if (flags & 0x01) { /* PES extension */
412  pes_ext = avio_r8(s->pb);
413  header_len--;
414  /* Skip PES private data, program packet sequence counter
415  * and P-STD buffer */
416  skip = (pes_ext >> 4) & 0xb;
417  skip += skip & 0x9;
418  if (pes_ext & 0x40 || skip > header_len) {
419  av_log(s, AV_LOG_WARNING, "pes_ext %X is invalid\n", pes_ext);
420  pes_ext = skip = 0;
421  }
422  avio_skip(s->pb, skip);
423  header_len -= skip;
424 
425  if (pes_ext & 0x01) { /* PES extension 2 */
426  ext2_len = avio_r8(s->pb);
427  header_len--;
428  if ((ext2_len & 0x7f) > 0) {
429  id_ext = avio_r8(s->pb);
430  if ((id_ext & 0x80) == 0)
431  startcode = ((startcode & 0xff) << 8) | id_ext;
432  header_len--;
433  }
434  }
435  }
436  if (header_len < 0)
437  goto error_redo;
438  avio_skip(s->pb, header_len);
439  } else if (c != 0xf)
440  goto redo;
441  }
442 
443  if (startcode == PRIVATE_STREAM_1) {
444  startcode = avio_r8(s->pb);
445  len--;
446  }
447  if (len < 0)
448  goto error_redo;
449  if (dts != AV_NOPTS_VALUE && ppos) {
450  int i;
451  for (i = 0; i < s->nb_streams; i++) {
452  if (startcode == s->streams[i]->id &&
453  s->pb->seekable /* index useless on streams anyway */) {
454  ff_reduce_index(s, i);
455  av_add_index_entry(s->streams[i], *ppos, dts, 0, 0,
456  AVINDEX_KEYFRAME /* FIXME keyframe? */);
457  }
458  }
459  }
460 
461  *pstart_code = startcode;
462  *ppts = pts;
463  *pdts = dts;
464  return len;
465 }
466 
468  AVPacket *pkt)
469 {
471  AVStream *st;
472  int len, startcode, i, es_type, ret;
473  int lpcm_header_len = -1; //Init to suppress warning
474  int request_probe= 0;
476  enum AVMediaType type;
477  int64_t pts, dts, dummy_pos; // dummy_pos is needed for the index building to work
478 
479 redo:
480  len = mpegps_read_pes_header(s, &dummy_pos, &startcode, &pts, &dts);
481  if (len < 0)
482  return len;
483 
484  if (startcode >= 0x80 && startcode <= 0xcf) {
485  if (len < 4)
486  goto skip;
487 
488  /* audio: skip header */
489  avio_r8(s->pb);
490  lpcm_header_len = avio_rb16(s->pb);
491  len -= 3;
492  if (startcode >= 0xb0 && startcode <= 0xbf) {
493  /* MLP/TrueHD audio has a 4-byte header */
494  avio_r8(s->pb);
495  len--;
496  }
497  }
498 
499  /* now find stream */
500  for (i = 0; i < s->nb_streams; i++) {
501  st = s->streams[i];
502  if (st->id == startcode)
503  goto found;
504  }
505 
506  es_type = m->psm_es_type[startcode & 0xff];
507  if (es_type == STREAM_TYPE_VIDEO_MPEG1) {
508  codec_id = AV_CODEC_ID_MPEG2VIDEO;
509  type = AVMEDIA_TYPE_VIDEO;
510  } else if (es_type == STREAM_TYPE_VIDEO_MPEG2) {
511  codec_id = AV_CODEC_ID_MPEG2VIDEO;
512  type = AVMEDIA_TYPE_VIDEO;
513  } else if (es_type == STREAM_TYPE_AUDIO_MPEG1 ||
514  es_type == STREAM_TYPE_AUDIO_MPEG2) {
515  codec_id = AV_CODEC_ID_MP3;
516  type = AVMEDIA_TYPE_AUDIO;
517  } else if (es_type == STREAM_TYPE_AUDIO_AAC) {
518  codec_id = AV_CODEC_ID_AAC;
519  type = AVMEDIA_TYPE_AUDIO;
520  } else if (es_type == STREAM_TYPE_VIDEO_MPEG4) {
521  codec_id = AV_CODEC_ID_MPEG4;
522  type = AVMEDIA_TYPE_VIDEO;
523  } else if (es_type == STREAM_TYPE_VIDEO_H264) {
524  codec_id = AV_CODEC_ID_H264;
525  type = AVMEDIA_TYPE_VIDEO;
526  } else if (es_type == STREAM_TYPE_AUDIO_AC3) {
527  codec_id = AV_CODEC_ID_AC3;
528  type = AVMEDIA_TYPE_AUDIO;
529  } else if (m->imkh_cctv && es_type == 0x91) {
530  codec_id = AV_CODEC_ID_PCM_MULAW;
531  type = AVMEDIA_TYPE_AUDIO;
532  } else if (startcode >= 0x1e0 && startcode <= 0x1ef) {
533  static const unsigned char avs_seqh[4] = { 0, 0, 1, 0xb0 };
534  unsigned char buf[8];
535 
536  avio_read(s->pb, buf, 8);
537  avio_seek(s->pb, -8, SEEK_CUR);
538  if (!memcmp(buf, avs_seqh, 4) && (buf[6] != 0 || buf[7] != 1))
539  codec_id = AV_CODEC_ID_CAVS;
540  else
541  request_probe= 1;
542  type = AVMEDIA_TYPE_VIDEO;
543  } else if (startcode == PRIVATE_STREAM_2) {
544  type = AVMEDIA_TYPE_DATA;
545  codec_id = AV_CODEC_ID_DVD_NAV;
546  } else if (startcode >= 0x1c0 && startcode <= 0x1df) {
547  type = AVMEDIA_TYPE_AUDIO;
548  if (m->sofdec > 0) {
549  codec_id = AV_CODEC_ID_ADPCM_ADX;
550  // Auto-detect AC-3
551  request_probe = 50;
552  } else {
553  codec_id = AV_CODEC_ID_MP2;
554  }
555  } else if (startcode >= 0x80 && startcode <= 0x87) {
556  type = AVMEDIA_TYPE_AUDIO;
557  codec_id = AV_CODEC_ID_AC3;
558  } else if ((startcode >= 0x88 && startcode <= 0x8f) ||
559  (startcode >= 0x98 && startcode <= 0x9f)) {
560  /* 0x90 - 0x97 is reserved for SDDS in DVD specs */
561  type = AVMEDIA_TYPE_AUDIO;
562  codec_id = AV_CODEC_ID_DTS;
563  } else if (startcode >= 0xa0 && startcode <= 0xaf) {
564  type = AVMEDIA_TYPE_AUDIO;
565  if (lpcm_header_len == 6) {
566  codec_id = AV_CODEC_ID_MLP;
567  } else {
568  codec_id = AV_CODEC_ID_PCM_DVD;
569  }
570  } else if (startcode >= 0xb0 && startcode <= 0xbf) {
571  type = AVMEDIA_TYPE_AUDIO;
572  codec_id = AV_CODEC_ID_TRUEHD;
573  } else if (startcode >= 0xc0 && startcode <= 0xcf) {
574  /* Used for both AC-3 and E-AC-3 in EVOB files */
575  type = AVMEDIA_TYPE_AUDIO;
576  codec_id = AV_CODEC_ID_AC3;
577  } else if (startcode >= 0x20 && startcode <= 0x3f) {
578  type = AVMEDIA_TYPE_SUBTITLE;
579  codec_id = AV_CODEC_ID_DVD_SUBTITLE;
580  } else if (startcode >= 0xfd55 && startcode <= 0xfd5f) {
581  type = AVMEDIA_TYPE_VIDEO;
582  codec_id = AV_CODEC_ID_VC1;
583  } else {
584 skip:
585  /* skip packet */
586  avio_skip(s->pb, len);
587  goto redo;
588  }
589  /* no stream found: add a new stream */
590  st = avformat_new_stream(s, NULL);
591  if (!st)
592  goto skip;
593  st->id = startcode;
594  st->codec->codec_type = type;
595  st->codec->codec_id = codec_id;
596  if (st->codec->codec_id == AV_CODEC_ID_PCM_MULAW) {
597  st->codec->channels = 1;
599  st->codec->sample_rate = 8000;
600  }
601  st->request_probe = request_probe;
603 
604 found:
605  if (st->discard >= AVDISCARD_ALL)
606  goto skip;
607  if (startcode >= 0xa0 && startcode <= 0xaf) {
608  if (lpcm_header_len == 6 && st->codec->codec_id == AV_CODEC_ID_MLP) {
609  if (len < 6)
610  goto skip;
611  avio_skip(s->pb, 6);
612  len -=6;
613  }
614  }
615  ret = av_get_packet(s->pb, pkt, len);
616 
617  pkt->pts = pts;
618  pkt->dts = dts;
619  pkt->pos = dummy_pos;
620  pkt->stream_index = st->index;
621  av_dlog(s, "%d: pts=%0.3f dts=%0.3f size=%d\n",
622  pkt->stream_index, pkt->pts / 90000.0, pkt->dts / 90000.0,
623  pkt->size);
624 
625  return (ret < 0) ? ret : 0;
626 }
627 
628 static int64_t mpegps_read_dts(AVFormatContext *s, int stream_index,
629  int64_t *ppos, int64_t pos_limit)
630 {
631  int len, startcode;
632  int64_t pos, pts, dts;
633 
634  pos = *ppos;
635  if (avio_seek(s->pb, pos, SEEK_SET) < 0)
636  return AV_NOPTS_VALUE;
637 
638  for (;;) {
639  len = mpegps_read_pes_header(s, &pos, &startcode, &pts, &dts);
640  if (len < 0) {
641  av_dlog(s, "none (ret=%d)\n", len);
642  return AV_NOPTS_VALUE;
643  }
644  if (startcode == s->streams[stream_index]->id &&
645  dts != AV_NOPTS_VALUE) {
646  break;
647  }
648  avio_skip(s->pb, len);
649  }
650  av_dlog(s, "pos=0x%"PRIx64" dts=0x%"PRIx64" %0.3f\n",
651  pos, dts, dts / 90000.0);
652  *ppos = pos;
653  return dts;
654 }
655 
657  .name = "mpeg",
658  .long_name = NULL_IF_CONFIG_SMALL("MPEG-PS (MPEG-2 Program Stream)"),
659  .priv_data_size = sizeof(MpegDemuxContext),
663  .read_timestamp = mpegps_read_dts,
665 };
666 
667 #if CONFIG_VOBSUB_DEMUXER
668 
669 #define REF_STRING "# VobSub index file,"
670 #define MAX_LINE_SIZE 2048
671 
672 static int vobsub_probe(AVProbeData *p)
673 {
674  if (!strncmp(p->buf, REF_STRING, sizeof(REF_STRING) - 1))
675  return AVPROBE_SCORE_MAX;
676  return 0;
677 }
678 
679 static int vobsub_read_header(AVFormatContext *s)
680 {
681  int i, ret = 0, header_parsed = 0, langidx = 0;
682  MpegDemuxContext *vobsub = s->priv_data;
683  char *sub_name = NULL;
684  size_t fname_len;
685  char *ext, *header_str;
686  AVBPrint header;
687  int64_t delay = 0;
688  AVStream *st = NULL;
689  int stream_id = -1;
690  char id[64] = {0};
691  char alt[MAX_LINE_SIZE] = {0};
693 
694  sub_name = av_strdup(s->filename);
695  fname_len = strlen(sub_name);
696  ext = sub_name - 3 + fname_len;
697  if (fname_len < 4 || *(ext - 1) != '.') {
698  av_log(s, AV_LOG_ERROR, "The input index filename is too short "
699  "to guess the associated .SUB file\n");
700  ret = AVERROR_INVALIDDATA;
701  goto end;
702  }
703  memcpy(ext, !strncmp(ext, "IDX", 3) ? "SUB" : "sub", 3);
704  av_log(s, AV_LOG_VERBOSE, "IDX/SUB: %s -> %s\n", s->filename, sub_name);
705 
706  if (!(iformat = av_find_input_format("mpeg"))) {
708  goto end;
709  }
710 
711  vobsub->sub_ctx = avformat_alloc_context();
712  if (!vobsub->sub_ctx) {
713  ret = AVERROR(ENOMEM);
714  goto end;
715  }
716 
717  if ((ret = ff_copy_whitelists(vobsub->sub_ctx, s)) < 0)
718  goto end;
719 
720  ret = avformat_open_input(&vobsub->sub_ctx, sub_name, iformat, NULL);
721  if (ret < 0) {
722  av_log(s, AV_LOG_ERROR, "Unable to open %s as MPEG subtitles\n", sub_name);
723  goto end;
724  }
725 
727  while (!avio_feof(s->pb)) {
728  char line[MAX_LINE_SIZE];
729  int len = ff_get_line(s->pb, line, sizeof(line));
730 
731  if (!len)
732  break;
733 
734  line[strcspn(line, "\r\n")] = 0;
735 
736  if (!strncmp(line, "id:", 3)) {
737  if (sscanf(line, "id: %63[^,], index: %u", id, &stream_id) != 2) {
738  av_log(s, AV_LOG_WARNING, "Unable to parse index line '%s', "
739  "assuming 'id: und, index: 0'\n", line);
740  strcpy(id, "und");
741  stream_id = 0;
742  }
743 
744  if (stream_id >= FF_ARRAY_ELEMS(vobsub->q)) {
745  av_log(s, AV_LOG_ERROR, "Maximum number of subtitles streams reached\n");
746  ret = AVERROR(EINVAL);
747  goto end;
748  }
749 
750  header_parsed = 1;
751  alt[0] = '\0';
752  /* We do not create the stream immediately to avoid adding empty
753  * streams. See the following timestamp entry. */
754 
755  av_log(s, AV_LOG_DEBUG, "IDX stream[%d] id=%s\n", stream_id, id);
756 
757  } else if (!strncmp(line, "timestamp:", 10)) {
758  AVPacket *sub;
759  int hh, mm, ss, ms;
760  int64_t pos, timestamp;
761  const char *p = line + 10;
762 
763  if (stream_id == -1) {
764  av_log(s, AV_LOG_ERROR, "Timestamp declared before any stream\n");
765  ret = AVERROR_INVALIDDATA;
766  goto end;
767  }
768 
769  if (!st || st->id != stream_id) {
770  st = avformat_new_stream(s, NULL);
771  if (!st) {
772  ret = AVERROR(ENOMEM);
773  goto end;
774  }
775  st->id = stream_id;
778  avpriv_set_pts_info(st, 64, 1, 1000);
779  av_dict_set(&st->metadata, "language", id, 0);
780  if (alt[0])
781  av_dict_set(&st->metadata, "title", alt, 0);
782  }
783 
784  if (sscanf(p, "%02d:%02d:%02d:%03d, filepos: %"SCNx64,
785  &hh, &mm, &ss, &ms, &pos) != 5) {
786  av_log(s, AV_LOG_ERROR, "Unable to parse timestamp line '%s', "
787  "abort parsing\n", line);
788  ret = AVERROR_INVALIDDATA;
789  goto end;
790  }
791  timestamp = (hh*3600LL + mm*60LL + ss) * 1000LL + ms + delay;
792  timestamp = av_rescale_q(timestamp, av_make_q(1, 1000), st->time_base);
793 
794  sub = ff_subtitles_queue_insert(&vobsub->q[s->nb_streams - 1], "", 0, 0);
795  if (!sub) {
796  ret = AVERROR(ENOMEM);
797  goto end;
798  }
799  sub->pos = pos;
800  sub->pts = timestamp;
801  sub->stream_index = s->nb_streams - 1;
802 
803  } else if (!strncmp(line, "alt:", 4)) {
804  const char *p = line + 4;
805 
806  while (*p == ' ')
807  p++;
808  av_log(s, AV_LOG_DEBUG, "IDX stream[%d] name=%s\n", stream_id, p);
809  av_strlcpy(alt, p, sizeof(alt));
810  header_parsed = 1;
811 
812  } else if (!strncmp(line, "delay:", 6)) {
813  int sign = 1, hh = 0, mm = 0, ss = 0, ms = 0;
814  const char *p = line + 6;
815 
816  while (*p == ' ')
817  p++;
818  if (*p == '-' || *p == '+') {
819  sign = *p == '-' ? -1 : 1;
820  p++;
821  }
822  sscanf(p, "%d:%d:%d:%d", &hh, &mm, &ss, &ms);
823  delay = ((hh*3600LL + mm*60LL + ss) * 1000LL + ms) * sign;
824 
825  } else if (!strncmp(line, "langidx:", 8)) {
826  const char *p = line + 8;
827 
828  if (sscanf(p, "%d", &langidx) != 1)
829  av_log(s, AV_LOG_ERROR, "Invalid langidx specified\n");
830 
831  } else if (!header_parsed) {
832  if (line[0] && line[0] != '#')
833  av_bprintf(&header, "%s\n", line);
834  }
835  }
836 
837  if (langidx < s->nb_streams)
839 
840  for (i = 0; i < s->nb_streams; i++) {
841  vobsub->q[i].sort = SUB_SORT_POS_TS;
842  ff_subtitles_queue_finalize(&vobsub->q[i]);
843  }
844 
845  if (!av_bprint_is_complete(&header)) {
846  av_bprint_finalize(&header, NULL);
847  ret = AVERROR(ENOMEM);
848  goto end;
849  }
850  av_bprint_finalize(&header, &header_str);
851  for (i = 0; i < s->nb_streams; i++) {
852  AVStream *sub_st = s->streams[i];
853  sub_st->codec->extradata = av_strdup(header_str);
854  sub_st->codec->extradata_size = header.len;
855  }
856  av_free(header_str);
857 
858 end:
859  av_free(sub_name);
860  return ret;
861 }
862 
863 static int vobsub_read_packet(AVFormatContext *s, AVPacket *pkt)
864 {
865  MpegDemuxContext *vobsub = s->priv_data;
867  AVIOContext *pb = vobsub->sub_ctx->pb;
868  int ret, psize, total_read = 0, i;
869  AVPacket idx_pkt;
870 
871  int64_t min_ts = INT64_MAX;
872  int sid = 0;
873  for (i = 0; i < s->nb_streams; i++) {
874  FFDemuxSubtitlesQueue *tmpq = &vobsub->q[i];
875  int64_t ts;
876  av_assert0(tmpq->nb_subs);
877  ts = tmpq->subs[tmpq->current_sub_idx].pts;
878  if (ts < min_ts) {
879  min_ts = ts;
880  sid = i;
881  }
882  }
883  q = &vobsub->q[sid];
884  ret = ff_subtitles_queue_read_packet(q, &idx_pkt);
885  if (ret < 0)
886  return ret;
887 
888  /* compute maximum packet size using the next packet position. This is
889  * useful when the len in the header is non-sense */
890  if (q->current_sub_idx < q->nb_subs) {
891  psize = q->subs[q->current_sub_idx].pos - idx_pkt.pos;
892  } else {
893  int64_t fsize = avio_size(pb);
894  psize = fsize < 0 ? 0xffff : fsize - idx_pkt.pos;
895  }
896 
897  avio_seek(pb, idx_pkt.pos, SEEK_SET);
898 
899  av_init_packet(pkt);
900  pkt->size = 0;
901  pkt->data = NULL;
902 
903  do {
904  int n, to_read, startcode;
905  int64_t pts, dts;
906  int64_t old_pos = avio_tell(pb), new_pos;
907  int pkt_size;
908 
909  ret = mpegps_read_pes_header(vobsub->sub_ctx, NULL, &startcode, &pts, &dts);
910  if (ret < 0) {
911  if (pkt->size) // raise packet even if incomplete
912  break;
913  goto fail;
914  }
915  to_read = ret & 0xffff;
916  new_pos = avio_tell(pb);
917  pkt_size = ret + (new_pos - old_pos);
918 
919  /* this prevents reads above the current packet */
920  if (total_read + pkt_size > psize)
921  break;
922  total_read += pkt_size;
923 
924  /* the current chunk doesn't match the stream index (unlikely) */
925  if ((startcode & 0x1f) != idx_pkt.stream_index)
926  break;
927 
928  ret = av_grow_packet(pkt, to_read);
929  if (ret < 0)
930  goto fail;
931 
932  n = avio_read(pb, pkt->data + (pkt->size - to_read), to_read);
933  if (n < to_read)
934  pkt->size -= to_read - n;
935  } while (total_read < psize);
936 
937  pkt->pts = pkt->dts = idx_pkt.pts;
938  pkt->pos = idx_pkt.pos;
939  pkt->stream_index = idx_pkt.stream_index;
940 
941  av_free_packet(&idx_pkt);
942  return 0;
943 
944 fail:
945  av_free_packet(pkt);
946  av_free_packet(&idx_pkt);
947  return ret;
948 }
949 
950 static int vobsub_read_seek(AVFormatContext *s, int stream_index,
951  int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
952 {
953  MpegDemuxContext *vobsub = s->priv_data;
954 
955  /* Rescale requested timestamps based on the first stream (timebase is the
956  * same for all subtitles stream within a .idx/.sub). Rescaling is done just
957  * like in avformat_seek_file(). */
958  if (stream_index == -1 && s->nb_streams != 1) {
959  int i, ret = 0;
960  AVRational time_base = s->streams[0]->time_base;
961  ts = av_rescale_q(ts, AV_TIME_BASE_Q, time_base);
962  min_ts = av_rescale_rnd(min_ts, time_base.den,
963  time_base.num * (int64_t)AV_TIME_BASE,
965  max_ts = av_rescale_rnd(max_ts, time_base.den,
966  time_base.num * (int64_t)AV_TIME_BASE,
968  for (i = 0; i < s->nb_streams; i++) {
969  int r = ff_subtitles_queue_seek(&vobsub->q[i], s, stream_index,
970  min_ts, ts, max_ts, flags);
971  if (r < 0)
972  ret = r;
973  }
974  return ret;
975  }
976 
977  if (stream_index == -1) // only 1 stream
978  stream_index = 0;
979  return ff_subtitles_queue_seek(&vobsub->q[stream_index], s, stream_index,
980  min_ts, ts, max_ts, flags);
981 }
982 
983 static int vobsub_read_close(AVFormatContext *s)
984 {
985  int i;
986  MpegDemuxContext *vobsub = s->priv_data;
987 
988  for (i = 0; i < s->nb_streams; i++)
989  ff_subtitles_queue_clean(&vobsub->q[i]);
990  if (vobsub->sub_ctx)
991  avformat_close_input(&vobsub->sub_ctx);
992  return 0;
993 }
994 
995 AVInputFormat ff_vobsub_demuxer = {
996  .name = "vobsub",
997  .long_name = NULL_IF_CONFIG_SMALL("VobSub subtitle format"),
998  .priv_data_size = sizeof(MpegDemuxContext),
999  .read_probe = vobsub_probe,
1000  .read_header = vobsub_read_header,
1001  .read_packet = vobsub_read_packet,
1002  .read_seek2 = vobsub_read_seek,
1003  .read_close = vobsub_read_close,
1004  .flags = AVFMT_SHOW_IDS,
1005  .extensions = "idx",
1006 };
1007 #endif