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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 # include "libavutil/opt.h"
30 #endif
31 
32 #include "libavutil/avassert.h"
33 
34 /*********************************************/
35 /* demux code */
36 
37 #define MAX_SYNC_SIZE 100000
38 
39 static int check_pes(const uint8_t *p, const uint8_t *end)
40 {
41  int pes1;
42  int pes2 = (p[3] & 0xC0) == 0x80 &&
43  (p[4] & 0xC0) != 0x40 &&
44  ((p[4] & 0xC0) == 0x00 ||
45  (p[4] & 0xC0) >> 2 == (p[6] & 0xF0));
46 
47  for (p += 3; p < end && *p == 0xFF; p++) ;
48  if ((*p & 0xC0) == 0x40)
49  p += 2;
50 
51  if ((*p & 0xF0) == 0x20)
52  pes1 = p[0] & p[2] & p[4] & 1;
53  else if ((*p & 0xF0) == 0x30)
54  pes1 = p[0] & p[2] & p[4] & p[5] & p[7] & p[9] & 1;
55  else
56  pes1 = *p == 0x0F;
57 
58  return pes1 || pes2;
59 }
60 
61 static int check_pack_header(const uint8_t *buf)
62 {
63  return (buf[1] & 0xC0) == 0x40 || (buf[1] & 0xF0) == 0x20;
64 }
65 
66 static int mpegps_probe(AVProbeData *p)
67 {
68  uint32_t code = -1;
69  int i;
70  int sys = 0, pspack = 0, priv1 = 0, vid = 0;
71  int audio = 0, invalid = 0, score = 0;
72  int endpes = 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 = endpes <= i && 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  endpes = i + len;
87  vid++;
88  }
89  // skip pes payload to avoid start code emulation for private
90  // and audio streams
91  else if ((code & 0xe0) == AUDIO_ID && pes) {audio++; i+=len;}
92  else if (code == PRIVATE_STREAM_1 && pes) {priv1++; i+=len;}
93  else if (code == 0x1fd && pes) vid++; //VC1
94 
95  else if ((code & 0xf0) == VIDEO_ID && !pes) invalid++;
96  else if ((code & 0xe0) == AUDIO_ID && !pes) invalid++;
97  else if (code == PRIVATE_STREAM_1 && !pes) invalid++;
98  }
99  }
100 
101  if (vid + audio > invalid + 1) /* invalid VDR files nd short PES streams */
102  score = AVPROBE_SCORE_EXTENSION / 2;
103 
104 // av_log(NULL, AV_LOG_ERROR, "vid:%d aud:%d sys:%d pspack:%d invalid:%d size:%d \n",
105 // vid, audio, sys, pspack, invalid, p->buf_size);
106 
107  if (sys > invalid && sys * 9 <= pspack * 10)
108  return (audio > 12 || vid > 3 || pspack > 2) ? AVPROBE_SCORE_EXTENSION + 2
109  : AVPROBE_SCORE_EXTENSION / 2 + 1; // 1 more than mp3
110  if (pspack > invalid && (priv1 + vid + audio) * 10 >= pspack * 9)
111  return pspack > 2 ? AVPROBE_SCORE_EXTENSION + 2
112  : AVPROBE_SCORE_EXTENSION / 2; // 1 more than .mpg
113  if ((!!vid ^ !!audio) && (audio > 4 || vid > 1) && !sys &&
114  !pspack && p->buf_size > 2048 && vid + audio > invalid) /* PES stream */
115  return (audio > 12 || vid > 3 + 2 * invalid) ? AVPROBE_SCORE_EXTENSION + 2
117 
118  // 02-Penguin.flac has sys:0 priv1:0 pspack:0 vid:0 audio:1
119  // mp3_misidentified_2.mp3 has sys:0 priv1:0 pspack:0 vid:0 audio:6
120  // Have\ Yourself\ a\ Merry\ Little\ Christmas.mp3 0 0 0 5 0 1 len:21618
121  return score;
122 }
123 
124 typedef struct MpegDemuxContext {
125  AVClass *class;
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  char *sub_name;
135 #endif
137 
139 {
141  char buffer[7];
142  int64_t last_pos = avio_tell(s->pb);
143 
144  m->header_state = 0xff;
146 
147  avio_get_str(s->pb, 6, buffer, sizeof(buffer));
148  if (!memcmp("IMKH", buffer, 4)) {
149  m->imkh_cctv = 1;
150  } else if (!memcmp("Sofdec", buffer, 6)) {
151  m->sofdec = 1;
152  } else
153  avio_seek(s->pb, last_pos, SEEK_SET);
154 
155  /* no need to do more */
156  return 0;
157 }
158 
159 static int64_t get_pts(AVIOContext *pb, int c)
160 {
161  uint8_t buf[5];
162 
163  buf[0] = c < 0 ? avio_r8(pb) : c;
164  avio_read(pb, buf + 1, 4);
165 
166  return ff_parse_pes_pts(buf);
167 }
168 
169 static int find_next_start_code(AVIOContext *pb, int *size_ptr,
170  int32_t *header_state)
171 {
172  unsigned int state, v;
173  int val, n;
174 
175  state = *header_state;
176  n = *size_ptr;
177  while (n > 0) {
178  if (avio_feof(pb))
179  break;
180  v = avio_r8(pb);
181  n--;
182  if (state == 0x000001) {
183  state = ((state << 8) | v) & 0xffffff;
184  val = state;
185  goto found;
186  }
187  state = ((state << 8) | v) & 0xffffff;
188  }
189  val = -1;
190 
191 found:
192  *header_state = state;
193  *size_ptr = n;
194  return val;
195 }
196 
197 /**
198  * Extract stream types from a program stream map
199  * According to ISO/IEC 13818-1 ('MPEG-2 Systems') table 2-35
200  *
201  * @return number of bytes occupied by PSM in the bitstream
202  */
204 {
205  int psm_length, ps_info_length, es_map_length;
206 
207  psm_length = avio_rb16(pb);
208  avio_r8(pb);
209  avio_r8(pb);
210  ps_info_length = avio_rb16(pb);
211 
212  /* skip program_stream_info */
213  avio_skip(pb, ps_info_length);
214  /*es_map_length = */avio_rb16(pb);
215  /* Ignore es_map_length, trust psm_length */
216  es_map_length = psm_length - ps_info_length - 10;
217 
218  /* at least one es available? */
219  while (es_map_length >= 4) {
220  unsigned char type = avio_r8(pb);
221  unsigned char es_id = avio_r8(pb);
222  uint16_t es_info_length = avio_rb16(pb);
223 
224  /* remember mapping from stream id to stream type */
225  m->psm_es_type[es_id] = type;
226  /* skip program_stream_info */
227  avio_skip(pb, es_info_length);
228  es_map_length -= 4 + es_info_length;
229  }
230  avio_rb32(pb); /* crc32 */
231  return 2 + psm_length;
232 }
233 
234 /* read the next PES header. Return its position in ppos
235  * (if not NULL), and its start code, pts and dts.
236  */
238  int64_t *ppos, int *pstart_code,
239  int64_t *ppts, int64_t *pdts)
240 {
242  int len, size, startcode, c, flags, header_len;
243  int pes_ext, ext2_len, id_ext, skip;
244  int64_t pts, dts;
245  int64_t last_sync = avio_tell(s->pb);
246 
247 error_redo:
248  avio_seek(s->pb, last_sync, SEEK_SET);
249 redo:
250  /* next start code (should be immediately after) */
251  m->header_state = 0xff;
252  size = MAX_SYNC_SIZE;
253  startcode = find_next_start_code(s->pb, &size, &m->header_state);
254  last_sync = avio_tell(s->pb);
255  if (startcode < 0) {
256  if (avio_feof(s->pb))
257  return AVERROR_EOF;
258  // FIXME we should remember header_state
259  return AVERROR(EAGAIN);
260  }
261 
262  if (startcode == PACK_START_CODE)
263  goto redo;
264  if (startcode == SYSTEM_HEADER_START_CODE)
265  goto redo;
266  if (startcode == PADDING_STREAM) {
267  avio_skip(s->pb, avio_rb16(s->pb));
268  goto redo;
269  }
270  if (startcode == PRIVATE_STREAM_2) {
271  if (!m->sofdec) {
272  /* Need to detect whether this from a DVD or a 'Sofdec' stream */
273  int len = avio_rb16(s->pb);
274  int bytesread = 0;
275  uint8_t *ps2buf = av_malloc(len);
276 
277  if (ps2buf) {
278  bytesread = avio_read(s->pb, ps2buf, len);
279 
280  if (bytesread != len) {
281  avio_skip(s->pb, len - bytesread);
282  } else {
283  uint8_t *p = 0;
284  if (len >= 6)
285  p = memchr(ps2buf, 'S', len - 5);
286 
287  if (p)
288  m->sofdec = !memcmp(p+1, "ofdec", 5);
289 
290  m->sofdec -= !m->sofdec;
291 
292  if (m->sofdec < 0) {
293  if (len == 980 && ps2buf[0] == 0) {
294  /* PCI structure? */
295  uint32_t startpts = AV_RB32(ps2buf + 0x0d);
296  uint32_t endpts = AV_RB32(ps2buf + 0x11);
297  uint8_t hours = ((ps2buf[0x19] >> 4) * 10) + (ps2buf[0x19] & 0x0f);
298  uint8_t mins = ((ps2buf[0x1a] >> 4) * 10) + (ps2buf[0x1a] & 0x0f);
299  uint8_t secs = ((ps2buf[0x1b] >> 4) * 10) + (ps2buf[0x1b] & 0x0f);
300 
301  m->dvd = (hours <= 23 &&
302  mins <= 59 &&
303  secs <= 59 &&
304  (ps2buf[0x19] & 0x0f) < 10 &&
305  (ps2buf[0x1a] & 0x0f) < 10 &&
306  (ps2buf[0x1b] & 0x0f) < 10 &&
307  endpts >= startpts);
308  } else if (len == 1018 && ps2buf[0] == 1) {
309  /* DSI structure? */
310  uint8_t hours = ((ps2buf[0x1d] >> 4) * 10) + (ps2buf[0x1d] & 0x0f);
311  uint8_t mins = ((ps2buf[0x1e] >> 4) * 10) + (ps2buf[0x1e] & 0x0f);
312  uint8_t secs = ((ps2buf[0x1f] >> 4) * 10) + (ps2buf[0x1f] & 0x0f);
313 
314  m->dvd = (hours <= 23 &&
315  mins <= 59 &&
316  secs <= 59 &&
317  (ps2buf[0x1d] & 0x0f) < 10 &&
318  (ps2buf[0x1e] & 0x0f) < 10 &&
319  (ps2buf[0x1f] & 0x0f) < 10);
320  }
321  }
322  }
323 
324  av_free(ps2buf);
325 
326  /* If this isn't a DVD packet or no memory
327  * could be allocated, just ignore it.
328  * If we did, move back to the start of the
329  * packet (plus 'length' field) */
330  if (!m->dvd || avio_skip(s->pb, -(len + 2)) < 0) {
331  /* Skip back failed.
332  * This packet will be lost but that can't be helped
333  * if we can't skip back
334  */
335  goto redo;
336  }
337  } else {
338  /* No memory */
339  avio_skip(s->pb, len);
340  goto redo;
341  }
342  } else if (!m->dvd) {
343  int len = avio_rb16(s->pb);
344  avio_skip(s->pb, len);
345  goto redo;
346  }
347  }
348  if (startcode == PROGRAM_STREAM_MAP) {
349  mpegps_psm_parse(m, s->pb);
350  goto redo;
351  }
352 
353  /* find matching stream */
354  if (!((startcode >= 0x1c0 && startcode <= 0x1df) ||
355  (startcode >= 0x1e0 && startcode <= 0x1ef) ||
356  (startcode == 0x1bd) ||
357  (startcode == PRIVATE_STREAM_2) ||
358  (startcode == 0x1fd)))
359  goto redo;
360  if (ppos) {
361  *ppos = avio_tell(s->pb) - 4;
362  }
363  len = avio_rb16(s->pb);
364  pts =
365  dts = AV_NOPTS_VALUE;
366  if (startcode != PRIVATE_STREAM_2)
367  {
368  /* stuffing */
369  for (;;) {
370  if (len < 1)
371  goto error_redo;
372  c = avio_r8(s->pb);
373  len--;
374  /* XXX: for mpeg1, should test only bit 7 */
375  if (c != 0xff)
376  break;
377  }
378  if ((c & 0xc0) == 0x40) {
379  /* buffer scale & size */
380  avio_r8(s->pb);
381  c = avio_r8(s->pb);
382  len -= 2;
383  }
384  if ((c & 0xe0) == 0x20) {
385  dts =
386  pts = get_pts(s->pb, c);
387  len -= 4;
388  if (c & 0x10) {
389  dts = get_pts(s->pb, -1);
390  len -= 5;
391  }
392  } else if ((c & 0xc0) == 0x80) {
393  /* mpeg 2 PES */
394  flags = avio_r8(s->pb);
395  header_len = avio_r8(s->pb);
396  len -= 2;
397  if (header_len > len)
398  goto error_redo;
399  len -= header_len;
400  if (flags & 0x80) {
401  dts = pts = get_pts(s->pb, -1);
402  header_len -= 5;
403  if (flags & 0x40) {
404  dts = get_pts(s->pb, -1);
405  header_len -= 5;
406  }
407  }
408  if (flags & 0x3f && header_len == 0) {
409  flags &= 0xC0;
410  av_log(s, AV_LOG_WARNING, "Further flags set but no bytes left\n");
411  }
412  if (flags & 0x01) { /* PES extension */
413  pes_ext = avio_r8(s->pb);
414  header_len--;
415  /* Skip PES private data, program packet sequence counter
416  * and P-STD buffer */
417  skip = (pes_ext >> 4) & 0xb;
418  skip += skip & 0x9;
419  if (pes_ext & 0x40 || skip > header_len) {
420  av_log(s, AV_LOG_WARNING, "pes_ext %X is invalid\n", pes_ext);
421  pes_ext = skip = 0;
422  }
423  avio_skip(s->pb, skip);
424  header_len -= skip;
425 
426  if (pes_ext & 0x01) { /* PES extension 2 */
427  ext2_len = avio_r8(s->pb);
428  header_len--;
429  if ((ext2_len & 0x7f) > 0) {
430  id_ext = avio_r8(s->pb);
431  if ((id_ext & 0x80) == 0)
432  startcode = ((startcode & 0xff) << 8) | id_ext;
433  header_len--;
434  }
435  }
436  }
437  if (header_len < 0)
438  goto error_redo;
439  avio_skip(s->pb, header_len);
440  } else if (c != 0xf)
441  goto redo;
442  }
443 
444  if (startcode == PRIVATE_STREAM_1) {
445  startcode = avio_r8(s->pb);
446  len--;
447  }
448  if (len < 0)
449  goto error_redo;
450  if (dts != AV_NOPTS_VALUE && ppos) {
451  int i;
452  for (i = 0; i < s->nb_streams; i++) {
453  if (startcode == s->streams[i]->id &&
454  s->pb->seekable /* index useless on streams anyway */) {
455  ff_reduce_index(s, i);
456  av_add_index_entry(s->streams[i], *ppos, dts, 0, 0,
457  AVINDEX_KEYFRAME /* FIXME keyframe? */);
458  }
459  }
460  }
461 
462  *pstart_code = startcode;
463  *ppts = pts;
464  *pdts = dts;
465  return len;
466 }
467 
469  AVPacket *pkt)
470 {
472  AVStream *st;
473  int len, startcode, i, es_type, ret;
474  int lpcm_header_len = -1; //Init to suppress warning
475  int request_probe= 0;
477  enum AVMediaType type;
478  int64_t pts, dts, dummy_pos; // dummy_pos is needed for the index building to work
479 
480 redo:
481  len = mpegps_read_pes_header(s, &dummy_pos, &startcode, &pts, &dts);
482  if (len < 0)
483  return len;
484 
485  if (startcode >= 0x80 && startcode <= 0xcf) {
486  if (len < 4)
487  goto skip;
488 
489  /* audio: skip header */
490  avio_r8(s->pb);
491  lpcm_header_len = avio_rb16(s->pb);
492  len -= 3;
493  if (startcode >= 0xb0 && startcode <= 0xbf) {
494  /* MLP/TrueHD audio has a 4-byte header */
495  avio_r8(s->pb);
496  len--;
497  }
498  }
499 
500  /* now find stream */
501  for (i = 0; i < s->nb_streams; i++) {
502  st = s->streams[i];
503  if (st->id == startcode)
504  goto found;
505  }
506 
507  es_type = m->psm_es_type[startcode & 0xff];
508  if (es_type == STREAM_TYPE_VIDEO_MPEG1) {
509  codec_id = AV_CODEC_ID_MPEG2VIDEO;
510  type = AVMEDIA_TYPE_VIDEO;
511  } else if (es_type == STREAM_TYPE_VIDEO_MPEG2) {
512  codec_id = AV_CODEC_ID_MPEG2VIDEO;
513  type = AVMEDIA_TYPE_VIDEO;
514  } else if (es_type == STREAM_TYPE_AUDIO_MPEG1 ||
515  es_type == STREAM_TYPE_AUDIO_MPEG2) {
516  codec_id = AV_CODEC_ID_MP3;
517  type = AVMEDIA_TYPE_AUDIO;
518  } else if (es_type == STREAM_TYPE_AUDIO_AAC) {
519  codec_id = AV_CODEC_ID_AAC;
520  type = AVMEDIA_TYPE_AUDIO;
521  } else if (es_type == STREAM_TYPE_VIDEO_MPEG4) {
522  codec_id = AV_CODEC_ID_MPEG4;
523  type = AVMEDIA_TYPE_VIDEO;
524  } else if (es_type == STREAM_TYPE_VIDEO_H264) {
525  codec_id = AV_CODEC_ID_H264;
526  type = AVMEDIA_TYPE_VIDEO;
527  } else if (es_type == STREAM_TYPE_AUDIO_AC3) {
528  codec_id = AV_CODEC_ID_AC3;
529  type = AVMEDIA_TYPE_AUDIO;
530  } else if (m->imkh_cctv && es_type == 0x91) {
531  codec_id = AV_CODEC_ID_PCM_MULAW;
532  type = AVMEDIA_TYPE_AUDIO;
533  } else if (startcode >= 0x1e0 && startcode <= 0x1ef) {
534  static const unsigned char avs_seqh[4] = { 0, 0, 1, 0xb0 };
535  unsigned char buf[8];
536 
537  avio_read(s->pb, buf, 8);
538  avio_seek(s->pb, -8, SEEK_CUR);
539  if (!memcmp(buf, avs_seqh, 4) && (buf[6] != 0 || buf[7] != 1))
540  codec_id = AV_CODEC_ID_CAVS;
541  else
542  request_probe= 1;
543  type = AVMEDIA_TYPE_VIDEO;
544  } else if (startcode == PRIVATE_STREAM_2) {
545  type = AVMEDIA_TYPE_DATA;
546  codec_id = AV_CODEC_ID_DVD_NAV;
547  } else if (startcode >= 0x1c0 && startcode <= 0x1df) {
548  type = AVMEDIA_TYPE_AUDIO;
549  if (m->sofdec > 0) {
550  codec_id = AV_CODEC_ID_ADPCM_ADX;
551  // Auto-detect AC-3
552  request_probe = 50;
553  } else if (m->imkh_cctv && startcode == 0x1c0) {
554  codec_id = AV_CODEC_ID_PCM_ALAW;
555  request_probe = 50;
556  } else {
557  codec_id = AV_CODEC_ID_MP2;
558  if (m->imkh_cctv)
559  request_probe = 25;
560  }
561  } else if (startcode >= 0x80 && startcode <= 0x87) {
562  type = AVMEDIA_TYPE_AUDIO;
563  codec_id = AV_CODEC_ID_AC3;
564  } else if ((startcode >= 0x88 && startcode <= 0x8f) ||
565  (startcode >= 0x98 && startcode <= 0x9f)) {
566  /* 0x90 - 0x97 is reserved for SDDS in DVD specs */
567  type = AVMEDIA_TYPE_AUDIO;
568  codec_id = AV_CODEC_ID_DTS;
569  } else if (startcode >= 0xa0 && startcode <= 0xaf) {
570  type = AVMEDIA_TYPE_AUDIO;
571  if (lpcm_header_len == 6) {
572  codec_id = AV_CODEC_ID_MLP;
573  } else {
574  codec_id = AV_CODEC_ID_PCM_DVD;
575  }
576  } else if (startcode >= 0xb0 && startcode <= 0xbf) {
577  type = AVMEDIA_TYPE_AUDIO;
578  codec_id = AV_CODEC_ID_TRUEHD;
579  } else if (startcode >= 0xc0 && startcode <= 0xcf) {
580  /* Used for both AC-3 and E-AC-3 in EVOB files */
581  type = AVMEDIA_TYPE_AUDIO;
582  codec_id = AV_CODEC_ID_AC3;
583  } else if (startcode >= 0x20 && startcode <= 0x3f) {
584  type = AVMEDIA_TYPE_SUBTITLE;
585  codec_id = AV_CODEC_ID_DVD_SUBTITLE;
586  } else if (startcode >= 0xfd55 && startcode <= 0xfd5f) {
587  type = AVMEDIA_TYPE_VIDEO;
588  codec_id = AV_CODEC_ID_VC1;
589  } else {
590 skip:
591  /* skip packet */
592  avio_skip(s->pb, len);
593  goto redo;
594  }
595  /* no stream found: add a new stream */
596  st = avformat_new_stream(s, NULL);
597  if (!st)
598  goto skip;
599  st->id = startcode;
600  st->codec->codec_type = type;
601  st->codec->codec_id = codec_id;
603  || st->codec->codec_id == AV_CODEC_ID_PCM_ALAW) {
604  st->codec->channels = 1;
606  st->codec->sample_rate = 8000;
607  }
608  st->request_probe = request_probe;
610 
611 found:
612  if (st->discard >= AVDISCARD_ALL)
613  goto skip;
614  if (startcode >= 0xa0 && startcode <= 0xaf) {
615  if (lpcm_header_len == 6 && st->codec->codec_id == AV_CODEC_ID_MLP) {
616  if (len < 6)
617  goto skip;
618  avio_skip(s->pb, 6);
619  len -=6;
620  }
621  }
622  ret = av_get_packet(s->pb, pkt, len);
623 
624  pkt->pts = pts;
625  pkt->dts = dts;
626  pkt->pos = dummy_pos;
627  pkt->stream_index = st->index;
628 
629  if (s->debug & FF_FDEBUG_TS)
630  av_log(s, AV_LOG_TRACE, "%d: pts=%0.3f dts=%0.3f size=%d\n",
631  pkt->stream_index, pkt->pts / 90000.0, pkt->dts / 90000.0,
632  pkt->size);
633 
634  return (ret < 0) ? ret : 0;
635 }
636 
637 static int64_t mpegps_read_dts(AVFormatContext *s, int stream_index,
638  int64_t *ppos, int64_t pos_limit)
639 {
640  int len, startcode;
641  int64_t pos, pts, dts;
642 
643  pos = *ppos;
644  if (avio_seek(s->pb, pos, SEEK_SET) < 0)
645  return AV_NOPTS_VALUE;
646 
647  for (;;) {
648  len = mpegps_read_pes_header(s, &pos, &startcode, &pts, &dts);
649  if (len < 0) {
650  if (s->debug & FF_FDEBUG_TS)
651  av_log(s, AV_LOG_TRACE, "none (ret=%d)\n", len);
652  return AV_NOPTS_VALUE;
653  }
654  if (startcode == s->streams[stream_index]->id &&
655  dts != AV_NOPTS_VALUE) {
656  break;
657  }
658  avio_skip(s->pb, len);
659  }
660  if (s->debug & FF_FDEBUG_TS)
661  av_log(s, AV_LOG_TRACE, "pos=0x%"PRIx64" dts=0x%"PRIx64" %0.3f\n",
662  pos, dts, dts / 90000.0);
663  *ppos = pos;
664  return dts;
665 }
666 
668  .name = "mpeg",
669  .long_name = NULL_IF_CONFIG_SMALL("MPEG-PS (MPEG-2 Program Stream)"),
670  .priv_data_size = sizeof(MpegDemuxContext),
674  .read_timestamp = mpegps_read_dts,
676 };
677 
678 #if CONFIG_VOBSUB_DEMUXER
679 
680 #define REF_STRING "# VobSub index file,"
681 #define MAX_LINE_SIZE 2048
682 
683 static int vobsub_probe(AVProbeData *p)
684 {
685  if (!strncmp(p->buf, REF_STRING, sizeof(REF_STRING) - 1))
686  return AVPROBE_SCORE_MAX;
687  return 0;
688 }
689 
690 static int vobsub_read_header(AVFormatContext *s)
691 {
692  int i, ret = 0, header_parsed = 0, langidx = 0;
693  MpegDemuxContext *vobsub = s->priv_data;
694  size_t fname_len;
695  char *header_str;
696  AVBPrint header;
697  int64_t delay = 0;
698  AVStream *st = NULL;
699  int stream_id = -1;
700  char id[64] = {0};
701  char alt[MAX_LINE_SIZE] = {0};
703 
704  if (!vobsub->sub_name) {
705  char *ext;
706  vobsub->sub_name = av_strdup(s->filename);
707  if (!vobsub->sub_name) {
708  ret = AVERROR(ENOMEM);
709  goto end;
710  }
711 
712  fname_len = strlen(vobsub->sub_name);
713  ext = vobsub->sub_name - 3 + fname_len;
714  if (fname_len < 4 || *(ext - 1) != '.') {
715  av_log(s, AV_LOG_ERROR, "The input index filename is too short "
716  "to guess the associated .SUB file\n");
717  ret = AVERROR_INVALIDDATA;
718  goto end;
719  }
720  memcpy(ext, !strncmp(ext, "IDX", 3) ? "SUB" : "sub", 3);
721  av_log(s, AV_LOG_VERBOSE, "IDX/SUB: %s -> %s\n", s->filename, vobsub->sub_name);
722  }
723 
724  if (!(iformat = av_find_input_format("mpeg"))) {
726  goto end;
727  }
728 
729  vobsub->sub_ctx = avformat_alloc_context();
730  if (!vobsub->sub_ctx) {
731  ret = AVERROR(ENOMEM);
732  goto end;
733  }
734 
735  if ((ret = ff_copy_whitelists(vobsub->sub_ctx, s)) < 0)
736  goto end;
737 
738  ret = avformat_open_input(&vobsub->sub_ctx, vobsub->sub_name, iformat, NULL);
739  if (ret < 0) {
740  av_log(s, AV_LOG_ERROR, "Unable to open %s as MPEG subtitles\n", vobsub->sub_name);
741  goto end;
742  }
743 
745  while (!avio_feof(s->pb)) {
746  char line[MAX_LINE_SIZE];
747  int len = ff_get_line(s->pb, line, sizeof(line));
748 
749  if (!len)
750  break;
751 
752  line[strcspn(line, "\r\n")] = 0;
753 
754  if (!strncmp(line, "id:", 3)) {
755  if (sscanf(line, "id: %63[^,], index: %u", id, &stream_id) != 2) {
756  av_log(s, AV_LOG_WARNING, "Unable to parse index line '%s', "
757  "assuming 'id: und, index: 0'\n", line);
758  strcpy(id, "und");
759  stream_id = 0;
760  }
761 
762  if (stream_id >= FF_ARRAY_ELEMS(vobsub->q)) {
763  av_log(s, AV_LOG_ERROR, "Maximum number of subtitles streams reached\n");
764  ret = AVERROR(EINVAL);
765  goto end;
766  }
767 
768  header_parsed = 1;
769  alt[0] = '\0';
770  /* We do not create the stream immediately to avoid adding empty
771  * streams. See the following timestamp entry. */
772 
773  av_log(s, AV_LOG_DEBUG, "IDX stream[%d] id=%s\n", stream_id, id);
774 
775  } else if (!strncmp(line, "timestamp:", 10)) {
776  AVPacket *sub;
777  int hh, mm, ss, ms;
778  int64_t pos, timestamp;
779  const char *p = line + 10;
780 
781  if (stream_id == -1) {
782  av_log(s, AV_LOG_ERROR, "Timestamp declared before any stream\n");
783  ret = AVERROR_INVALIDDATA;
784  goto end;
785  }
786 
787  if (!st || st->id != stream_id) {
788  st = avformat_new_stream(s, NULL);
789  if (!st) {
790  ret = AVERROR(ENOMEM);
791  goto end;
792  }
793  st->id = stream_id;
796  avpriv_set_pts_info(st, 64, 1, 1000);
797  av_dict_set(&st->metadata, "language", id, 0);
798  if (alt[0])
799  av_dict_set(&st->metadata, "title", alt, 0);
800  }
801 
802  if (sscanf(p, "%02d:%02d:%02d:%03d, filepos: %"SCNx64,
803  &hh, &mm, &ss, &ms, &pos) != 5) {
804  av_log(s, AV_LOG_ERROR, "Unable to parse timestamp line '%s', "
805  "abort parsing\n", line);
806  ret = AVERROR_INVALIDDATA;
807  goto end;
808  }
809  timestamp = (hh*3600LL + mm*60LL + ss) * 1000LL + ms + delay;
810  timestamp = av_rescale_q(timestamp, av_make_q(1, 1000), st->time_base);
811 
812  sub = ff_subtitles_queue_insert(&vobsub->q[s->nb_streams - 1], "", 0, 0);
813  if (!sub) {
814  ret = AVERROR(ENOMEM);
815  goto end;
816  }
817  sub->pos = pos;
818  sub->pts = timestamp;
819  sub->stream_index = s->nb_streams - 1;
820 
821  } else if (!strncmp(line, "alt:", 4)) {
822  const char *p = line + 4;
823 
824  while (*p == ' ')
825  p++;
826  av_log(s, AV_LOG_DEBUG, "IDX stream[%d] name=%s\n", stream_id, p);
827  av_strlcpy(alt, p, sizeof(alt));
828  header_parsed = 1;
829 
830  } else if (!strncmp(line, "delay:", 6)) {
831  int sign = 1, hh = 0, mm = 0, ss = 0, ms = 0;
832  const char *p = line + 6;
833 
834  while (*p == ' ')
835  p++;
836  if (*p == '-' || *p == '+') {
837  sign = *p == '-' ? -1 : 1;
838  p++;
839  }
840  sscanf(p, "%d:%d:%d:%d", &hh, &mm, &ss, &ms);
841  delay = ((hh*3600LL + mm*60LL + ss) * 1000LL + ms) * sign;
842 
843  } else if (!strncmp(line, "langidx:", 8)) {
844  const char *p = line + 8;
845 
846  if (sscanf(p, "%d", &langidx) != 1)
847  av_log(s, AV_LOG_ERROR, "Invalid langidx specified\n");
848 
849  } else if (!header_parsed) {
850  if (line[0] && line[0] != '#')
851  av_bprintf(&header, "%s\n", line);
852  }
853  }
854 
855  if (langidx < s->nb_streams)
857 
858  for (i = 0; i < s->nb_streams; i++) {
859  vobsub->q[i].sort = SUB_SORT_POS_TS;
860  ff_subtitles_queue_finalize(&vobsub->q[i]);
861  }
862 
863  if (!av_bprint_is_complete(&header)) {
864  av_bprint_finalize(&header, NULL);
865  ret = AVERROR(ENOMEM);
866  goto end;
867  }
868  av_bprint_finalize(&header, &header_str);
869  for (i = 0; i < s->nb_streams; i++) {
870  AVStream *sub_st = s->streams[i];
871  sub_st->codec->extradata = av_strdup(header_str);
872  sub_st->codec->extradata_size = header.len;
873  }
874  av_free(header_str);
875 
876 end:
877  return ret;
878 }
879 
880 static int vobsub_read_packet(AVFormatContext *s, AVPacket *pkt)
881 {
882  MpegDemuxContext *vobsub = s->priv_data;
884  AVIOContext *pb = vobsub->sub_ctx->pb;
885  int ret, psize, total_read = 0, i;
886  AVPacket idx_pkt;
887 
888  int64_t min_ts = INT64_MAX;
889  int sid = 0;
890  for (i = 0; i < s->nb_streams; i++) {
891  FFDemuxSubtitlesQueue *tmpq = &vobsub->q[i];
892  int64_t ts;
893  av_assert0(tmpq->nb_subs);
894  ts = tmpq->subs[tmpq->current_sub_idx].pts;
895  if (ts < min_ts) {
896  min_ts = ts;
897  sid = i;
898  }
899  }
900  q = &vobsub->q[sid];
901  ret = ff_subtitles_queue_read_packet(q, &idx_pkt);
902  if (ret < 0)
903  return ret;
904 
905  /* compute maximum packet size using the next packet position. This is
906  * useful when the len in the header is non-sense */
907  if (q->current_sub_idx < q->nb_subs) {
908  psize = q->subs[q->current_sub_idx].pos - idx_pkt.pos;
909  } else {
910  int64_t fsize = avio_size(pb);
911  psize = fsize < 0 ? 0xffff : fsize - idx_pkt.pos;
912  }
913 
914  avio_seek(pb, idx_pkt.pos, SEEK_SET);
915 
916  av_init_packet(pkt);
917  pkt->size = 0;
918  pkt->data = NULL;
919 
920  do {
921  int n, to_read, startcode;
922  int64_t pts, dts;
923  int64_t old_pos = avio_tell(pb), new_pos;
924  int pkt_size;
925 
926  ret = mpegps_read_pes_header(vobsub->sub_ctx, NULL, &startcode, &pts, &dts);
927  if (ret < 0) {
928  if (pkt->size) // raise packet even if incomplete
929  break;
930  goto fail;
931  }
932  to_read = ret & 0xffff;
933  new_pos = avio_tell(pb);
934  pkt_size = ret + (new_pos - old_pos);
935 
936  /* this prevents reads above the current packet */
937  if (total_read + pkt_size > psize)
938  break;
939  total_read += pkt_size;
940 
941  /* the current chunk doesn't match the stream index (unlikely) */
942  if ((startcode & 0x1f) != idx_pkt.stream_index)
943  break;
944 
945  ret = av_grow_packet(pkt, to_read);
946  if (ret < 0)
947  goto fail;
948 
949  n = avio_read(pb, pkt->data + (pkt->size - to_read), to_read);
950  if (n < to_read)
951  pkt->size -= to_read - n;
952  } while (total_read < psize);
953 
954  pkt->pts = pkt->dts = idx_pkt.pts;
955  pkt->pos = idx_pkt.pos;
956  pkt->stream_index = idx_pkt.stream_index;
957 
958  av_free_packet(&idx_pkt);
959  return 0;
960 
961 fail:
962  av_free_packet(pkt);
963  av_free_packet(&idx_pkt);
964  return ret;
965 }
966 
967 static int vobsub_read_seek(AVFormatContext *s, int stream_index,
968  int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
969 {
970  MpegDemuxContext *vobsub = s->priv_data;
971 
972  /* Rescale requested timestamps based on the first stream (timebase is the
973  * same for all subtitles stream within a .idx/.sub). Rescaling is done just
974  * like in avformat_seek_file(). */
975  if (stream_index == -1 && s->nb_streams != 1) {
976  int i, ret = 0;
977  AVRational time_base = s->streams[0]->time_base;
978  ts = av_rescale_q(ts, AV_TIME_BASE_Q, time_base);
979  min_ts = av_rescale_rnd(min_ts, time_base.den,
980  time_base.num * (int64_t)AV_TIME_BASE,
982  max_ts = av_rescale_rnd(max_ts, time_base.den,
983  time_base.num * (int64_t)AV_TIME_BASE,
985  for (i = 0; i < s->nb_streams; i++) {
986  int r = ff_subtitles_queue_seek(&vobsub->q[i], s, stream_index,
987  min_ts, ts, max_ts, flags);
988  if (r < 0)
989  ret = r;
990  }
991  return ret;
992  }
993 
994  if (stream_index == -1) // only 1 stream
995  stream_index = 0;
996  return ff_subtitles_queue_seek(&vobsub->q[stream_index], s, stream_index,
997  min_ts, ts, max_ts, flags);
998 }
999 
1000 static int vobsub_read_close(AVFormatContext *s)
1001 {
1002  int i;
1003  MpegDemuxContext *vobsub = s->priv_data;
1004 
1005  for (i = 0; i < s->nb_streams; i++)
1006  ff_subtitles_queue_clean(&vobsub->q[i]);
1007  if (vobsub->sub_ctx)
1008  avformat_close_input(&vobsub->sub_ctx);
1009  return 0;
1010 }
1011 
1012 static const AVOption options[] = {
1013  { "sub_name", "URI for .sub file", offsetof(MpegDemuxContext, sub_name), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, AV_OPT_FLAG_DECODING_PARAM },
1014  { NULL }
1015 };
1016 
1017 static const AVClass vobsub_demuxer_class = {
1018  .class_name = "vobsub",
1019  .item_name = av_default_item_name,
1020  .option = options,
1021  .version = LIBAVUTIL_VERSION_INT,
1022 };
1023 
1024 AVInputFormat ff_vobsub_demuxer = {
1025  .name = "vobsub",
1026  .long_name = NULL_IF_CONFIG_SMALL("VobSub subtitle format"),
1027  .priv_data_size = sizeof(MpegDemuxContext),
1028  .read_probe = vobsub_probe,
1029  .read_header = vobsub_read_header,
1030  .read_packet = vobsub_read_packet,
1031  .read_seek2 = vobsub_read_seek,
1032  .read_close = vobsub_read_close,
1033  .flags = AVFMT_SHOW_IDS,
1034  .extensions = "idx",
1035  .priv_class = &vobsub_demuxer_class,
1036 };
1037 #endif