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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 
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  int pes1;
41  int pes2= (p[3] & 0xC0) == 0x80
42  && (p[4] & 0xC0) != 0x40
43  &&((p[4] & 0xC0) == 0x00 || (p[4]&0xC0)>>2 == (p[6]&0xF0));
44 
45  for(p+=3; p<end && *p == 0xFF; p++);
46  if((*p&0xC0) == 0x40) p+=2;
47  if((*p&0xF0) == 0x20){
48  pes1= p[0]&p[2]&p[4]&1;
49  }else if((*p&0xF0) == 0x30){
50  pes1= p[0]&p[2]&p[4]&p[5]&p[7]&p[9]&1;
51  }else
52  pes1 = *p == 0x0F;
53 
54  return pes1||pes2;
55 }
56 
57 static int check_pack_header(const uint8_t *buf) {
58  return (buf[1] & 0xC0) == 0x40 || (buf[1] & 0xF0) == 0x20;
59 }
60 
61 static int mpegps_probe(AVProbeData *p)
62 {
63  uint32_t code= -1;
64  int sys=0, pspack=0, priv1=0, vid=0, audio=0, invalid=0;
65  int i;
66  int score=0;
67 
68  for(i=0; i<p->buf_size; i++){
69  code = (code<<8) + p->buf[i];
70  if ((code & 0xffffff00) == 0x100) {
71  int len= p->buf[i+1] << 8 | p->buf[i+2];
72  int pes= check_pes(p->buf+i, p->buf+p->buf_size);
73  int pack = check_pack_header(p->buf+i);
74 
75  if(code == SYSTEM_HEADER_START_CODE) sys++;
76  else if(code == PACK_START_CODE && pack) pspack++;
77  else if((code & 0xf0) == VIDEO_ID && pes) vid++;
78  // skip pes payload to avoid start code emulation for private
79  // and audio streams
80  else if((code & 0xe0) == AUDIO_ID && pes) {audio++; i+=len;}
81  else if(code == PRIVATE_STREAM_1 && pes) {priv1++; i+=len;}
82  else if(code == 0x1fd && pes) vid++; //VC1
83 
84  else if((code & 0xf0) == VIDEO_ID && !pes) invalid++;
85  else if((code & 0xe0) == AUDIO_ID && !pes) invalid++;
86  else if(code == PRIVATE_STREAM_1 && !pes) invalid++;
87  }
88  }
89 
90  if(vid+audio > invalid+1) /* invalid VDR files nd short PES streams */
91  score= AVPROBE_SCORE_MAX/4;
92 
93  if(sys>invalid && sys*9 <= pspack*10)
94  return (audio > 12 || vid > 3 || pspack > 2) ? AVPROBE_SCORE_MAX/2+2 : AVPROBE_SCORE_MAX/4; // +1 for .mpg
95  if(pspack > invalid && (priv1+vid+audio)*10 >= pspack*9)
96  return pspack > 2 ? AVPROBE_SCORE_MAX/2+2 : AVPROBE_SCORE_MAX/4; // +1 for .mpg
97  if((!!vid ^ !!audio) && (audio > 4 || vid > 1) && !sys && !pspack && p->buf_size>2048 && vid + audio > invalid) /* PES stream */
98  return (audio > 12 || vid > 3 + 2*invalid) ? AVPROBE_SCORE_MAX/2+2 : AVPROBE_SCORE_MAX/4;
99 
100  //02-Penguin.flac has sys:0 priv1:0 pspack:0 vid:0 audio:1
101  //mp3_misidentified_2.mp3 has sys:0 priv1:0 pspack:0 vid:0 audio:6
102  //Have\ Yourself\ a\ Merry\ Little\ Christmas.mp3 0 0 0 5 0 1 len:21618
103  return score;
104 }
105 
106 
107 typedef struct MpegDemuxContext {
109  unsigned char psm_es_type[256];
110  int sofdec;
111 #if CONFIG_VOBSUB_DEMUXER
112  AVFormatContext *sub_ctx;
114 #endif
116 
118 {
120  const char *sofdec = "Sofdec";
121  int v, i = 0;
122  int64_t last_pos = avio_tell(s->pb);
123 
124  m->header_state = 0xff;
126 
127  m->sofdec = -1;
128  do {
129  v = avio_r8(s->pb);
130  m->sofdec++;
131  } while (v == sofdec[i] && i++ < 6);
132 
133  m->sofdec = (m->sofdec == 6) ? 1 : 0;
134 
135  if (!m->sofdec)
136  avio_seek(s->pb, last_pos, SEEK_SET);
137 
138  /* no need to do more */
139  return 0;
140 }
141 
142 static int64_t get_pts(AVIOContext *pb, int c)
143 {
144  uint8_t buf[5];
145 
146  buf[0] = c<0 ? avio_r8(pb) : c;
147  avio_read(pb, buf+1, 4);
148 
149  return ff_parse_pes_pts(buf);
150 }
151 
152 static int find_next_start_code(AVIOContext *pb, int *size_ptr,
153  int32_t *header_state)
154 {
155  unsigned int state, v;
156  int val, n;
157 
158  state = *header_state;
159  n = *size_ptr;
160  while (n > 0) {
161  if (url_feof(pb))
162  break;
163  v = avio_r8(pb);
164  n--;
165  if (state == 0x000001) {
166  state = ((state << 8) | v) & 0xffffff;
167  val = state;
168  goto found;
169  }
170  state = ((state << 8) | v) & 0xffffff;
171  }
172  val = -1;
173  found:
174  *header_state = state;
175  *size_ptr = n;
176  return val;
177 }
178 
179 /**
180  * Extract stream types from a program stream map
181  * According to ISO/IEC 13818-1 ('MPEG-2 Systems') table 2-35
182  *
183  * @return number of bytes occupied by PSM in the bitstream
184  */
186 {
187  int psm_length, ps_info_length, es_map_length;
188 
189  psm_length = avio_rb16(pb);
190  avio_r8(pb);
191  avio_r8(pb);
192  ps_info_length = avio_rb16(pb);
193 
194  /* skip program_stream_info */
195  avio_skip(pb, ps_info_length);
196  es_map_length = avio_rb16(pb);
197 
198  /* at least one es available? */
199  while (es_map_length >= 4){
200  unsigned char type = avio_r8(pb);
201  unsigned char es_id = avio_r8(pb);
202  uint16_t es_info_length = avio_rb16(pb);
203  /* remember mapping from stream id to stream type */
204  m->psm_es_type[es_id] = type;
205  /* skip program_stream_info */
206  avio_skip(pb, es_info_length);
207  es_map_length -= 4 + es_info_length;
208  }
209  avio_rb32(pb); /* crc32 */
210  return 2 + psm_length;
211 }
212 
213 /* read the next PES header. Return its position in ppos
214  (if not NULL), and its start code, pts and dts.
215  */
217  int64_t *ppos, int *pstart_code,
218  int64_t *ppts, int64_t *pdts)
219 {
221  int len, size, startcode, c, flags, header_len;
222  int pes_ext, ext2_len, id_ext, skip;
223  int64_t pts, dts;
224  int64_t last_sync= avio_tell(s->pb);
225 
226  error_redo:
227  avio_seek(s->pb, last_sync, SEEK_SET);
228  redo:
229  /* next start code (should be immediately after) */
230  m->header_state = 0xff;
231  size = MAX_SYNC_SIZE;
232  startcode = find_next_start_code(s->pb, &size, &m->header_state);
233  last_sync = avio_tell(s->pb);
234  if (startcode < 0){
235  if(url_feof(s->pb))
236  return AVERROR_EOF;
237  //FIXME we should remember header_state
238  return AVERROR(EAGAIN);
239  }
240 
241  if (startcode == PACK_START_CODE)
242  goto redo;
243  if (startcode == SYSTEM_HEADER_START_CODE)
244  goto redo;
245  if (startcode == PADDING_STREAM) {
246  avio_skip(s->pb, avio_rb16(s->pb));
247  goto redo;
248  }
249  if (startcode == PRIVATE_STREAM_2) {
250  len = avio_rb16(s->pb);
251  if (!m->sofdec) {
252  while (len-- >= 6) {
253  if (avio_r8(s->pb) == 'S') {
254  uint8_t buf[5];
255  avio_read(s->pb, buf, sizeof(buf));
256  m->sofdec = !memcmp(buf, "ofdec", 5);
257  len -= sizeof(buf);
258  break;
259  }
260  }
261  m->sofdec -= !m->sofdec;
262  }
263  avio_skip(s->pb, len);
264  goto redo;
265  }
266  if (startcode == PROGRAM_STREAM_MAP) {
267  mpegps_psm_parse(m, s->pb);
268  goto redo;
269  }
270 
271  /* find matching stream */
272  if (!((startcode >= 0x1c0 && startcode <= 0x1df) ||
273  (startcode >= 0x1e0 && startcode <= 0x1ef) ||
274  (startcode == 0x1bd) || (startcode == 0x1fd)))
275  goto redo;
276  if (ppos) {
277  *ppos = avio_tell(s->pb) - 4;
278  }
279  len = avio_rb16(s->pb);
280  pts =
281  dts = AV_NOPTS_VALUE;
282  /* stuffing */
283  for(;;) {
284  if (len < 1)
285  goto error_redo;
286  c = avio_r8(s->pb);
287  len--;
288  /* XXX: for mpeg1, should test only bit 7 */
289  if (c != 0xff)
290  break;
291  }
292  if ((c & 0xc0) == 0x40) {
293  /* buffer scale & size */
294  avio_r8(s->pb);
295  c = avio_r8(s->pb);
296  len -= 2;
297  }
298  if ((c & 0xe0) == 0x20) {
299  dts = pts = get_pts(s->pb, c);
300  len -= 4;
301  if (c & 0x10){
302  dts = get_pts(s->pb, -1);
303  len -= 5;
304  }
305  } else if ((c & 0xc0) == 0x80) {
306  /* mpeg 2 PES */
307  flags = avio_r8(s->pb);
308  header_len = avio_r8(s->pb);
309  len -= 2;
310  if (header_len > len)
311  goto error_redo;
312  len -= header_len;
313  if (flags & 0x80) {
314  dts = pts = get_pts(s->pb, -1);
315  header_len -= 5;
316  if (flags & 0x40) {
317  dts = get_pts(s->pb, -1);
318  header_len -= 5;
319  }
320  }
321  if (flags & 0x3f && header_len == 0){
322  flags &= 0xC0;
323  av_log(s, AV_LOG_WARNING, "Further flags set but no bytes left\n");
324  }
325  if (flags & 0x01) { /* PES extension */
326  pes_ext = avio_r8(s->pb);
327  header_len--;
328  /* Skip PES private data, program packet sequence counter and P-STD buffer */
329  skip = (pes_ext >> 4) & 0xb;
330  skip += skip & 0x9;
331  if (pes_ext & 0x40 || skip > header_len){
332  av_log(s, AV_LOG_WARNING, "pes_ext %X is invalid\n", pes_ext);
333  pes_ext=skip=0;
334  }
335  avio_skip(s->pb, skip);
336  header_len -= skip;
337 
338  if (pes_ext & 0x01) { /* PES extension 2 */
339  ext2_len = avio_r8(s->pb);
340  header_len--;
341  if ((ext2_len & 0x7f) > 0) {
342  id_ext = avio_r8(s->pb);
343  if ((id_ext & 0x80) == 0)
344  startcode = ((startcode & 0xff) << 8) | id_ext;
345  header_len--;
346  }
347  }
348  }
349  if(header_len < 0)
350  goto error_redo;
351  avio_skip(s->pb, header_len);
352  }
353  else if( c!= 0xf )
354  goto redo;
355 
356  if (startcode == PRIVATE_STREAM_1) {
357  startcode = avio_r8(s->pb);
358  len--;
359  }
360  if(len<0)
361  goto error_redo;
362  if(dts != AV_NOPTS_VALUE && ppos){
363  int i;
364  for(i=0; i<s->nb_streams; i++){
365  if(startcode == s->streams[i]->id &&
366  s->pb->seekable /* index useless on streams anyway */) {
367  ff_reduce_index(s, i);
368  av_add_index_entry(s->streams[i], *ppos, dts, 0, 0, AVINDEX_KEYFRAME /* FIXME keyframe? */);
369  }
370  }
371  }
372 
373  *pstart_code = startcode;
374  *ppts = pts;
375  *pdts = dts;
376  return len;
377 }
378 
380  AVPacket *pkt)
381 {
383  AVStream *st;
384  int len, startcode, i, es_type, ret;
385  int lpcm_header_len = -1; //Init to supress warning
386  int request_probe= 0;
388  enum AVMediaType type;
389  int64_t pts, dts, dummy_pos; //dummy_pos is needed for the index building to work
390 
391  redo:
392  len = mpegps_read_pes_header(s, &dummy_pos, &startcode, &pts, &dts);
393  if (len < 0)
394  return len;
395 
396  if (startcode >= 0x80 && startcode <= 0xcf) {
397  if(len < 4)
398  goto skip;
399 
400  /* audio: skip header */
401  avio_r8(s->pb);
402  lpcm_header_len = avio_rb16(s->pb);
403  len -= 3;
404  if (startcode >= 0xb0 && startcode <= 0xbf) {
405  /* MLP/TrueHD audio has a 4-byte header */
406  avio_r8(s->pb);
407  len--;
408  }
409  }
410 
411  /* now find stream */
412  for(i=0;i<s->nb_streams;i++) {
413  st = s->streams[i];
414  if (st->id == startcode)
415  goto found;
416  }
417 
418  es_type = m->psm_es_type[startcode & 0xff];
419  if(es_type == STREAM_TYPE_VIDEO_MPEG1){
420  codec_id = AV_CODEC_ID_MPEG2VIDEO;
421  type = AVMEDIA_TYPE_VIDEO;
422  } else if(es_type == STREAM_TYPE_VIDEO_MPEG2){
423  codec_id = AV_CODEC_ID_MPEG2VIDEO;
424  type = AVMEDIA_TYPE_VIDEO;
425  } else if(es_type == STREAM_TYPE_AUDIO_MPEG1 ||
426  es_type == STREAM_TYPE_AUDIO_MPEG2){
427  codec_id = AV_CODEC_ID_MP3;
428  type = AVMEDIA_TYPE_AUDIO;
429  } else if(es_type == STREAM_TYPE_AUDIO_AAC){
430  codec_id = AV_CODEC_ID_AAC;
431  type = AVMEDIA_TYPE_AUDIO;
432  } else if(es_type == STREAM_TYPE_VIDEO_MPEG4){
433  codec_id = AV_CODEC_ID_MPEG4;
434  type = AVMEDIA_TYPE_VIDEO;
435  } else if(es_type == STREAM_TYPE_VIDEO_H264){
436  codec_id = AV_CODEC_ID_H264;
437  type = AVMEDIA_TYPE_VIDEO;
438  } else if(es_type == STREAM_TYPE_AUDIO_AC3){
439  codec_id = AV_CODEC_ID_AC3;
440  type = AVMEDIA_TYPE_AUDIO;
441  } else if (startcode >= 0x1e0 && startcode <= 0x1ef) {
442  static const unsigned char avs_seqh[4] = { 0, 0, 1, 0xb0 };
443  unsigned char buf[8];
444  avio_read(s->pb, buf, 8);
445  avio_seek(s->pb, -8, SEEK_CUR);
446  if(!memcmp(buf, avs_seqh, 4) && (buf[6] != 0 || buf[7] != 1))
447  codec_id = AV_CODEC_ID_CAVS;
448  else
449  request_probe= 1;
450  type = AVMEDIA_TYPE_VIDEO;
451  } else if (startcode >= 0x1c0 && startcode <= 0x1df) {
452  type = AVMEDIA_TYPE_AUDIO;
453  codec_id = m->sofdec > 0 ? AV_CODEC_ID_ADPCM_ADX : AV_CODEC_ID_MP2;
454  } else if (startcode >= 0x80 && startcode <= 0x87) {
455  type = AVMEDIA_TYPE_AUDIO;
456  codec_id = AV_CODEC_ID_AC3;
457  } else if ( ( startcode >= 0x88 && startcode <= 0x8f)
458  ||( startcode >= 0x98 && startcode <= 0x9f)) {
459  /* 0x90 - 0x97 is reserved for SDDS in DVD specs */
460  type = AVMEDIA_TYPE_AUDIO;
461  codec_id = AV_CODEC_ID_DTS;
462  } else if (startcode >= 0xa0 && startcode <= 0xaf) {
463  type = AVMEDIA_TYPE_AUDIO;
464  if(lpcm_header_len == 6) {
465  codec_id = AV_CODEC_ID_MLP;
466  } else {
467  /* 16 bit form will be handled as AV_CODEC_ID_PCM_S16BE */
468  codec_id = AV_CODEC_ID_PCM_DVD;
469  }
470  } else if (startcode >= 0xb0 && startcode <= 0xbf) {
471  type = AVMEDIA_TYPE_AUDIO;
472  codec_id = AV_CODEC_ID_TRUEHD;
473  } else if (startcode >= 0xc0 && startcode <= 0xcf) {
474  /* Used for both AC-3 and E-AC-3 in EVOB files */
475  type = AVMEDIA_TYPE_AUDIO;
476  codec_id = AV_CODEC_ID_AC3;
477  } else if (startcode >= 0x20 && startcode <= 0x3f) {
478  type = AVMEDIA_TYPE_SUBTITLE;
479  codec_id = AV_CODEC_ID_DVD_SUBTITLE;
480  } else if (startcode >= 0xfd55 && startcode <= 0xfd5f) {
481  type = AVMEDIA_TYPE_VIDEO;
482  codec_id = AV_CODEC_ID_VC1;
483  } else {
484  skip:
485  /* skip packet */
486  avio_skip(s->pb, len);
487  goto redo;
488  }
489  /* no stream found: add a new stream */
490  st = avformat_new_stream(s, NULL);
491  if (!st)
492  goto skip;
493  st->id = startcode;
494  st->codec->codec_type = type;
495  st->codec->codec_id = codec_id;
496  st->request_probe = request_probe;
497  if (codec_id != AV_CODEC_ID_PCM_S16BE)
499  found:
500  if(st->discard >= AVDISCARD_ALL)
501  goto skip;
502  if (startcode >= 0xa0 && startcode <= 0xaf) {
503  if (lpcm_header_len == 6 && st->codec->codec_id == AV_CODEC_ID_MLP) {
504  if (len < 6)
505  goto skip;
506  avio_skip(s->pb, 6);
507  len -=6;
508  } else {
509  int b1, freq;
510 
511  /* for LPCM, we just skip the header and consider it is raw
512  audio data */
513  if (len <= 3)
514  goto skip;
515  avio_r8(s->pb); /* emphasis (1), muse(1), reserved(1), frame number(5) */
516  b1 = avio_r8(s->pb); /* quant (2), freq(2), reserved(1), channels(3) */
517  avio_r8(s->pb); /* dynamic range control (0x80 = off) */
518  len -= 3;
519  freq = (b1 >> 4) & 3;
520  st->codec->sample_rate = lpcm_freq_tab[freq];
521  st->codec->channels = 1 + (b1 & 7);
522  st->codec->bits_per_coded_sample = 16 + ((b1 >> 6) & 3) * 4;
523  st->codec->bit_rate = st->codec->channels *
524  st->codec->sample_rate *
526  if (st->codec->bits_per_coded_sample == 16)
528  else if (st->codec->bits_per_coded_sample == 28)
529  return AVERROR(EINVAL);
530  }
531  }
532  ret = av_get_packet(s->pb, pkt, len);
533  pkt->pts = pts;
534  pkt->dts = dts;
535  pkt->pos = dummy_pos;
536  pkt->stream_index = st->index;
537  av_dlog(s, "%d: pts=%0.3f dts=%0.3f size=%d\n",
538  pkt->stream_index, pkt->pts / 90000.0, pkt->dts / 90000.0,
539  pkt->size);
540 
541  return (ret < 0) ? ret : 0;
542 }
543 
544 static int64_t mpegps_read_dts(AVFormatContext *s, int stream_index,
545  int64_t *ppos, int64_t pos_limit)
546 {
547  int len, startcode;
548  int64_t pos, pts, dts;
549 
550  pos = *ppos;
551  if (avio_seek(s->pb, pos, SEEK_SET) < 0)
552  return AV_NOPTS_VALUE;
553 
554  for(;;) {
555  len = mpegps_read_pes_header(s, &pos, &startcode, &pts, &dts);
556  if (len < 0) {
557  av_dlog(s, "none (ret=%d)\n", len);
558  return AV_NOPTS_VALUE;
559  }
560  if (startcode == s->streams[stream_index]->id &&
561  dts != AV_NOPTS_VALUE) {
562  break;
563  }
564  avio_skip(s->pb, len);
565  }
566  av_dlog(s, "pos=0x%"PRIx64" dts=0x%"PRIx64" %0.3f\n",
567  pos, dts, dts / 90000.0);
568  *ppos = pos;
569  return dts;
570 }
571 
573  .name = "mpeg",
574  .long_name = NULL_IF_CONFIG_SMALL("MPEG-PS (MPEG-2 Program Stream)"),
575  .priv_data_size = sizeof(MpegDemuxContext),
579  .read_timestamp = mpegps_read_dts,
581 };
582 
583 #if CONFIG_VOBSUB_DEMUXER
584 
585 #define REF_STRING "# VobSub index file,"
586 
587 static int vobsub_probe(AVProbeData *p)
588 {
589  if (!strncmp(p->buf, REF_STRING, sizeof(REF_STRING) - 1))
590  return AVPROBE_SCORE_MAX;
591  return 0;
592 }
593 
594 static int vobsub_read_header(AVFormatContext *s)
595 {
596  int i, ret = 0, header_parsed = 0, langidx = 0;
597  MpegDemuxContext *vobsub = s->priv_data;
598  char *sub_name = NULL;
599  size_t fname_len;
600  char *ext, *header_str;
601  AVBPrint header;
602  int64_t delay = 0;
603  AVStream *st = NULL;
604 
605  sub_name = av_strdup(s->filename);
606  fname_len = strlen(sub_name);
607  ext = sub_name - 3 + fname_len;
608  if (fname_len < 4 || *(ext - 1) != '.') {
609  av_log(s, AV_LOG_ERROR, "The input index filename is too short "
610  "to guess the associated .SUB file\n");
611  ret = AVERROR_INVALIDDATA;
612  goto end;
613  }
614  memcpy(ext, !strncmp(ext, "IDX", 3) ? "SUB" : "sub", 3);
615  av_log(s, AV_LOG_VERBOSE, "IDX/SUB: %s -> %s\n", s->filename, sub_name);
616  ret = avformat_open_input(&vobsub->sub_ctx, sub_name, &ff_mpegps_demuxer, NULL);
617  if (ret < 0) {
618  av_log(s, AV_LOG_ERROR, "Unable to open %s as MPEG subtitles\n", sub_name);
619  goto end;
620  }
621 
623  while (!url_feof(s->pb)) {
624  char line[2048];
625  int len = ff_get_line(s->pb, line, sizeof(line));
626 
627  if (!len)
628  break;
629 
630  line[strcspn(line, "\r\n")] = 0;
631 
632  if (!strncmp(line, "id:", 3)) {
633  int n, stream_id = 0;
634  char id[64] = {0};
635 
636  n = sscanf(line, "id: %63[^,], index: %u", id, &stream_id);
637  if (n != 2) {
638  av_log(s, AV_LOG_WARNING, "Unable to parse index line '%s', "
639  "assuming 'id: und, index: 0'\n", line);
640  strcpy(id, "und");
641  stream_id = 0;
642  }
643 
644  st = avformat_new_stream(s, NULL);
645  if (!st) {
646  ret = AVERROR(ENOMEM);
647  goto end;
648  }
649  st->id = stream_id;
652  av_dict_set(&st->metadata, "language", id, 0);
653  av_log(s, AV_LOG_DEBUG, "IDX stream[%d] id=%s\n", stream_id, id);
654  header_parsed = 1;
655 
656  } else if (st && !strncmp(line, "timestamp:", 10)) {
657  AVPacket *sub;
658  int hh, mm, ss, ms;
659  int64_t pos, timestamp;
660  const char *p = line + 10;
661 
662  if (sscanf(p, "%02d:%02d:%02d:%03d, filepos: %"PRIx64,
663  &hh, &mm, &ss, &ms, &pos) != 5) {
664  av_log(s, AV_LOG_ERROR, "Unable to parse timestamp line '%s', "
665  "abort parsing\n", line);
666  break;
667  }
668  timestamp = (hh*3600LL + mm*60LL + ss) * 1000LL + ms + delay;
669  timestamp = av_rescale_q(timestamp, (AVRational){1,1000}, st->time_base);
670 
671  sub = ff_subtitles_queue_insert(&vobsub->q, "", 0, 0);
672  if (!sub) {
673  ret = AVERROR(ENOMEM);
674  goto end;
675  }
676  sub->pos = pos;
677  sub->pts = timestamp;
678  sub->stream_index = s->nb_streams - 1;
679 
680  } else if (st && !strncmp(line, "alt:", 4)) {
681  const char *p = line + 4;
682 
683  while (*p == ' ')
684  p++;
685  av_dict_set(&st->metadata, "title", p, 0);
686  av_log(s, AV_LOG_DEBUG, "IDX stream[%d] name=%s\n", st->id, p);
687  header_parsed = 1;
688 
689  } else if (!strncmp(line, "delay:", 6)) {
690  int sign = 1, hh = 0, mm = 0, ss = 0, ms = 0;
691  const char *p = line + 6;
692 
693  while (*p == ' ')
694  p++;
695  if (*p == '-' || *p == '+') {
696  sign = *p == '-' ? -1 : 1;
697  p++;
698  }
699  sscanf(p, "%d:%d:%d:%d", &hh, &mm, &ss, &ms);
700  delay = ((hh*3600LL + mm*60LL + ss) * 1000LL + ms) * sign;
701 
702  } else if (!strncmp(line, "langidx:", 8)) {
703  const char *p = line + 8;
704 
705  if (sscanf(p, "%d", &langidx) != 1)
706  av_log(s, AV_LOG_ERROR, "Invalid langidx specified\n");
707 
708  } else if (!header_parsed) {
709  if (line[0] && line[0] != '#')
710  av_bprintf(&header, "%s\n", line);
711  }
712  }
713 
714  if (langidx < s->nb_streams)
716 
717  ff_subtitles_queue_finalize(&vobsub->q);
718 
719  if (!av_bprint_is_complete(&header)) {
720  av_bprint_finalize(&header, NULL);
721  ret = AVERROR(ENOMEM);
722  goto end;
723  }
724  av_bprint_finalize(&header, &header_str);
725  for (i = 0; i < s->nb_streams; i++) {
726  AVStream *sub_st = s->streams[i];
727  sub_st->codec->extradata = av_strdup(header_str);
728  sub_st->codec->extradata_size = header.len;
729  }
730  av_free(header_str);
731 
732 end:
733  av_free(sub_name);
734  return ret;
735 }
736 
737 static int vobsub_read_packet(AVFormatContext *s, AVPacket *pkt)
738 {
739  MpegDemuxContext *vobsub = s->priv_data;
740  FFDemuxSubtitlesQueue *q = &vobsub->q;
741  AVIOContext *pb = vobsub->sub_ctx->pb;
742  int ret, psize, len16 = -1;
743  AVPacket idx_pkt;
744 
745  ret = ff_subtitles_queue_read_packet(q, &idx_pkt);
746  if (ret < 0)
747  return ret;
748 
749  /* compute maximum packet size using the next packet position. This is
750  * useful when the len in the header is non-sense */
751  if (q->current_sub_idx < q->nb_subs) {
752  psize = q->subs[q->current_sub_idx].pos - idx_pkt.pos;
753  } else {
754  int64_t fsize = avio_size(pb);
755  psize = fsize < 0 ? 0xffff : fsize - idx_pkt.pos;
756  }
757 
758  avio_seek(pb, idx_pkt.pos, SEEK_SET);
759 
760  av_init_packet(pkt);
761  pkt->size = 0;
762  pkt->data = NULL;
763 
764  do {
765  int n, to_read, startcode;
766  int64_t pts, dts;
767 
768  ret = mpegps_read_pes_header(vobsub->sub_ctx, NULL, &startcode, &pts, &dts);
769  if (ret < 0)
770  return ret;
771  to_read = ret & 0xffff;
772 
773  /* this prevents reads above the current packet */
774  if (pkt->size + to_read > psize)
775  break;
776 
777  /* if the len is computed, we check for overread */
778  if (len16 != -1 && pkt->size + to_read > len16)
779  break;
780 
781  /* the current chunk doesn't match the stream index (unlikely) */
782  if ((startcode & 0x1f) != idx_pkt.stream_index)
783  break;
784 
785  ret = av_grow_packet(pkt, to_read);
786  if (ret < 0)
787  return ret;
788 
789  n = avio_read(pb, pkt->data + (pkt->size - to_read), to_read);
790  if (n < to_read)
791  pkt->size -= to_read - n;
792 
793  /* first chunk contains the total len of the packet to raise */
794  if (len16 == -1 && n > 2)
795  len16 = AV_RB16(pkt->data);
796  } while (len16 != -1 && pkt->size != len16);
797 
798  pkt->pts = pkt->dts = idx_pkt.pts;
799  pkt->pos = idx_pkt.pos;
800  pkt->stream_index = idx_pkt.stream_index;
801 
802  return 0;
803 }
804 
805 static int vobsub_read_seek(AVFormatContext *s, int stream_index,
806  int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
807 {
808  MpegDemuxContext *vobsub = s->priv_data;
809  return ff_subtitles_queue_seek(&vobsub->q, s, stream_index,
810  min_ts, ts, max_ts, flags);
811 }
812 
813 static int vobsub_read_close(AVFormatContext *s)
814 {
815  MpegDemuxContext *vobsub = s->priv_data;
816  ff_subtitles_queue_clean(&vobsub->q);
817  if (vobsub->sub_ctx)
818  avformat_close_input(&vobsub->sub_ctx);
819  return 0;
820 }
821 
822 AVInputFormat ff_vobsub_demuxer = {
823  .name = "vobsub",
824  .long_name = NULL_IF_CONFIG_SMALL("VobSub subtitle format"),
825  .priv_data_size = sizeof(MpegDemuxContext),
826  .read_probe = vobsub_probe,
827  .read_header = vobsub_read_header,
828  .read_packet = vobsub_read_packet,
829  .read_seek2 = vobsub_read_seek,
830  .read_close = vobsub_read_close,
831  .flags = AVFMT_SHOW_IDS,
832  .extensions = "idx",
833 };
834 #endif