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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 
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 more than .mpg
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 
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 
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 
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 (url_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  */
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  */
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 (url_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 
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 
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 
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 
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 (!url_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*3600LL + mm*60LL + ss) * 1000LL + 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", st->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*3600LL + mm*60LL + ss) * 1000LL + 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 
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 
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 
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
Generated on Sun Jul 20 2014 23:06:04 for FFmpeg by   doxygen 1.8.2