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avidec.c
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1 /*
2  * AVI demuxer
3  * Copyright (c) 2001 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 <stdint.h>
23 
24 #include "libavutil/avassert.h"
25 #include "libavutil/avstring.h"
26 #include "libavutil/bswap.h"
27 #include "libavutil/opt.h"
28 #include "libavutil/dict.h"
29 #include "libavutil/internal.h"
30 #include "libavutil/intreadwrite.h"
31 #include "libavutil/mathematics.h"
32 #include "avformat.h"
33 #include "avi.h"
34 #include "dv.h"
35 #include "internal.h"
36 #include "riff.h"
37 
38 typedef struct AVIStream {
39  int64_t frame_offset; /* current frame (video) or byte (audio) counter
40  * (used to compute the pts) */
41  int remaining;
42  int packet_size;
43 
44  uint32_t scale;
45  uint32_t rate;
46  int sample_size; /* size of one sample (or packet)
47  * (in the rate/scale sense) in bytes */
48 
49  int64_t cum_len; /* temporary storage (used during seek) */
50  int prefix; /* normally 'd'<<8 + 'c' or 'w'<<8 + 'b' */
51  int prefix_count;
52  uint32_t pal[256];
53  int has_pal;
54  int dshow_block_align; /* block align variable used to emulate bugs in
55  * the MS dshow demuxer */
56 
57  AVFormatContext *sub_ctx;
58  AVPacket sub_pkt;
59  uint8_t *sub_buffer;
60 
61  int64_t seek_pos;
62 } AVIStream;
63 
64 typedef struct {
65  const AVClass *class;
66  int64_t riff_end;
67  int64_t movi_end;
68  int64_t fsize;
69  int64_t io_fsize;
70  int64_t movi_list;
71  int64_t last_pkt_pos;
72  int index_loaded;
73  int is_odml;
74  int non_interleaved;
75  int stream_index;
76  DVDemuxContext *dv_demux;
77  int odml_depth;
78  int use_odml;
79 #define MAX_ODML_DEPTH 1000
80  int64_t dts_max;
81 } AVIContext;
82 
83 
84 static const AVOption options[] = {
85  { "use_odml", "use odml index", offsetof(AVIContext, use_odml), AV_OPT_TYPE_INT, {.i64 = 1}, -1, 1, AV_OPT_FLAG_DECODING_PARAM},
86  { NULL },
87 };
88 
89 static const AVClass demuxer_class = {
90  .class_name = "avi",
91  .item_name = av_default_item_name,
92  .option = options,
93  .version = LIBAVUTIL_VERSION_INT,
94  .category = AV_CLASS_CATEGORY_DEMUXER,
95 };
96 
97 
98 static const char avi_headers[][8] = {
99  { 'R', 'I', 'F', 'F', 'A', 'V', 'I', ' ' },
100  { 'R', 'I', 'F', 'F', 'A', 'V', 'I', 'X' },
101  { 'R', 'I', 'F', 'F', 'A', 'V', 'I', 0x19 },
102  { 'O', 'N', '2', ' ', 'O', 'N', '2', 'f' },
103  { 'R', 'I', 'F', 'F', 'A', 'M', 'V', ' ' },
104  { 0 }
105 };
106 
107 static const AVMetadataConv avi_metadata_conv[] = {
108  { "strn", "title" },
109  { 0 },
110 };
111 
112 static int avi_load_index(AVFormatContext *s);
113 static int guess_ni_flag(AVFormatContext *s);
114 
115 #define print_tag(str, tag, size) \
116  av_dlog(NULL, "pos:%"PRIX64" %s: tag=%c%c%c%c size=0x%x\n", \
117  avio_tell(pb), str, tag & 0xff, \
118  (tag >> 8) & 0xff, \
119  (tag >> 16) & 0xff, \
120  (tag >> 24) & 0xff, \
121  size)
122 
123 static inline int get_duration(AVIStream *ast, int len)
124 {
125  if (ast->sample_size)
126  return len;
127  else if (ast->dshow_block_align)
128  return (len + ast->dshow_block_align - 1) / ast->dshow_block_align;
129  else
130  return 1;
131 }
132 
133 static int get_riff(AVFormatContext *s, AVIOContext *pb)
134 {
135  AVIContext *avi = s->priv_data;
136  char header[8];
137  int i;
138 
139  /* check RIFF header */
140  avio_read(pb, header, 4);
141  avi->riff_end = avio_rl32(pb); /* RIFF chunk size */
142  avi->riff_end += avio_tell(pb); /* RIFF chunk end */
143  avio_read(pb, header + 4, 4);
144 
145  for (i = 0; avi_headers[i][0]; i++)
146  if (!memcmp(header, avi_headers[i], 8))
147  break;
148  if (!avi_headers[i][0])
149  return AVERROR_INVALIDDATA;
150 
151  if (header[7] == 0x19)
152  av_log(s, AV_LOG_INFO,
153  "This file has been generated by a totally broken muxer.\n");
154 
155  return 0;
156 }
157 
158 static int read_braindead_odml_indx(AVFormatContext *s, int frame_num)
159 {
160  AVIContext *avi = s->priv_data;
161  AVIOContext *pb = s->pb;
162  int longs_pre_entry = avio_rl16(pb);
163  int index_sub_type = avio_r8(pb);
164  int index_type = avio_r8(pb);
165  int entries_in_use = avio_rl32(pb);
166  int chunk_id = avio_rl32(pb);
167  int64_t base = avio_rl64(pb);
168  int stream_id = ((chunk_id & 0xFF) - '0') * 10 +
169  ((chunk_id >> 8 & 0xFF) - '0');
170  AVStream *st;
171  AVIStream *ast;
172  int i;
173  int64_t last_pos = -1;
174  int64_t filesize = avi->fsize;
175 
176  av_dlog(s,
177  "longs_pre_entry:%d index_type:%d entries_in_use:%d "
178  "chunk_id:%X base:%16"PRIX64"\n",
179  longs_pre_entry,
180  index_type,
181  entries_in_use,
182  chunk_id,
183  base);
184 
185  if (stream_id >= s->nb_streams || stream_id < 0)
186  return AVERROR_INVALIDDATA;
187  st = s->streams[stream_id];
188  ast = st->priv_data;
189 
190  if (index_sub_type)
191  return AVERROR_INVALIDDATA;
192 
193  avio_rl32(pb);
194 
195  if (index_type && longs_pre_entry != 2)
196  return AVERROR_INVALIDDATA;
197  if (index_type > 1)
198  return AVERROR_INVALIDDATA;
199 
200  if (filesize > 0 && base >= filesize) {
201  av_log(s, AV_LOG_ERROR, "ODML index invalid\n");
202  if (base >> 32 == (base & 0xFFFFFFFF) &&
203  (base & 0xFFFFFFFF) < filesize &&
204  filesize <= 0xFFFFFFFF)
205  base &= 0xFFFFFFFF;
206  else
207  return AVERROR_INVALIDDATA;
208  }
209 
210  for (i = 0; i < entries_in_use; i++) {
211  if (index_type) {
212  int64_t pos = avio_rl32(pb) + base - 8;
213  int len = avio_rl32(pb);
214  int key = len >= 0;
215  len &= 0x7FFFFFFF;
216 
217 #ifdef DEBUG_SEEK
218  av_log(s, AV_LOG_ERROR, "pos:%"PRId64", len:%X\n", pos, len);
219 #endif
220  if (url_feof(pb))
221  return AVERROR_INVALIDDATA;
222 
223  if (last_pos == pos || pos == base - 8)
224  avi->non_interleaved = 1;
225  if (last_pos != pos && (len || !ast->sample_size))
226  av_add_index_entry(st, pos, ast->cum_len, len, 0,
227  key ? AVINDEX_KEYFRAME : 0);
228 
229  ast->cum_len += get_duration(ast, len);
230  last_pos = pos;
231  } else {
232  int64_t offset, pos;
233  int duration;
234  offset = avio_rl64(pb);
235  avio_rl32(pb); /* size */
236  duration = avio_rl32(pb);
237 
238  if (url_feof(pb))
239  return AVERROR_INVALIDDATA;
240 
241  pos = avio_tell(pb);
242 
243  if (avi->odml_depth > MAX_ODML_DEPTH) {
244  av_log(s, AV_LOG_ERROR, "Too deeply nested ODML indexes\n");
245  return AVERROR_INVALIDDATA;
246  }
247 
248  if (avio_seek(pb, offset + 8, SEEK_SET) < 0)
249  return -1;
250  avi->odml_depth++;
251  read_braindead_odml_indx(s, frame_num);
252  avi->odml_depth--;
253  frame_num += duration;
254 
255  if (avio_seek(pb, pos, SEEK_SET) < 0) {
256  av_log(s, AV_LOG_ERROR, "Failed to restore position after reading index\n");
257  return -1;
258  }
259 
260  }
261  }
262  avi->index_loaded = 2;
263  return 0;
264 }
265 
266 static void clean_index(AVFormatContext *s)
267 {
268  int i;
269  int64_t j;
270 
271  for (i = 0; i < s->nb_streams; i++) {
272  AVStream *st = s->streams[i];
273  AVIStream *ast = st->priv_data;
274  int n = st->nb_index_entries;
275  int max = ast->sample_size;
276  int64_t pos, size, ts;
277 
278  if (n != 1 || ast->sample_size == 0)
279  continue;
280 
281  while (max < 1024)
282  max += max;
283 
284  pos = st->index_entries[0].pos;
285  size = st->index_entries[0].size;
286  ts = st->index_entries[0].timestamp;
287 
288  for (j = 0; j < size; j += max)
289  av_add_index_entry(st, pos + j, ts + j, FFMIN(max, size - j), 0,
290  AVINDEX_KEYFRAME);
291  }
292 }
293 
294 static int avi_read_tag(AVFormatContext *s, AVStream *st, uint32_t tag,
295  uint32_t size)
296 {
297  AVIOContext *pb = s->pb;
298  char key[5] = { 0 };
299  char *value;
300 
301  size += (size & 1);
302 
303  if (size == UINT_MAX)
304  return AVERROR(EINVAL);
305  value = av_malloc(size + 1);
306  if (!value)
307  return AVERROR(ENOMEM);
308  avio_read(pb, value, size);
309  value[size] = 0;
310 
311  AV_WL32(key, tag);
312 
313  return av_dict_set(st ? &st->metadata : &s->metadata, key, value,
314  AV_DICT_DONT_STRDUP_VAL);
315 }
316 
317 static const char months[12][4] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun",
318  "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
319 
320 static void avi_metadata_creation_time(AVDictionary **metadata, char *date)
321 {
322  char month[4], time[9], buffer[64];
323  int i, day, year;
324  /* parse standard AVI date format (ie. "Mon Mar 10 15:04:43 2003") */
325  if (sscanf(date, "%*3s%*[ ]%3s%*[ ]%2d%*[ ]%8s%*[ ]%4d",
326  month, &day, time, &year) == 4) {
327  for (i = 0; i < 12; i++)
328  if (!av_strcasecmp(month, months[i])) {
329  snprintf(buffer, sizeof(buffer), "%.4d-%.2d-%.2d %s",
330  year, i + 1, day, time);
331  av_dict_set(metadata, "creation_time", buffer, 0);
332  }
333  } else if (date[4] == '/' && date[7] == '/') {
334  date[4] = date[7] = '-';
335  av_dict_set(metadata, "creation_time", date, 0);
336  }
337 }
338 
339 static void avi_read_nikon(AVFormatContext *s, uint64_t end)
340 {
341  while (avio_tell(s->pb) < end) {
342  uint32_t tag = avio_rl32(s->pb);
343  uint32_t size = avio_rl32(s->pb);
344  switch (tag) {
345  case MKTAG('n', 'c', 't', 'g'): /* Nikon Tags */
346  {
347  uint64_t tag_end = avio_tell(s->pb) + size;
348  while (avio_tell(s->pb) < tag_end) {
349  uint16_t tag = avio_rl16(s->pb);
350  uint16_t size = avio_rl16(s->pb);
351  const char *name = NULL;
352  char buffer[64] = { 0 };
353  size = FFMIN(size, tag_end - avio_tell(s->pb));
354  size -= avio_read(s->pb, buffer,
355  FFMIN(size, sizeof(buffer) - 1));
356  switch (tag) {
357  case 0x03:
358  name = "maker";
359  break;
360  case 0x04:
361  name = "model";
362  break;
363  case 0x13:
364  name = "creation_time";
365  if (buffer[4] == ':' && buffer[7] == ':')
366  buffer[4] = buffer[7] = '-';
367  break;
368  }
369  if (name)
370  av_dict_set(&s->metadata, name, buffer, 0);
371  avio_skip(s->pb, size);
372  }
373  break;
374  }
375  default:
376  avio_skip(s->pb, size);
377  break;
378  }
379  }
380 }
381 
382 static int avi_read_header(AVFormatContext *s)
383 {
384  AVIContext *avi = s->priv_data;
385  AVIOContext *pb = s->pb;
386  unsigned int tag, tag1, handler;
387  int codec_type, stream_index, frame_period;
388  unsigned int size;
389  int i;
390  AVStream *st;
391  AVIStream *ast = NULL;
392  int avih_width = 0, avih_height = 0;
393  int amv_file_format = 0;
394  uint64_t list_end = 0;
395  int ret;
396  AVDictionaryEntry *dict_entry;
397 
398  avi->stream_index = -1;
399 
400  ret = get_riff(s, pb);
401  if (ret < 0)
402  return ret;
403 
404  av_log(avi, AV_LOG_DEBUG, "use odml:%d\n", avi->use_odml);
405 
406  avi->io_fsize = avi->fsize = avio_size(pb);
407  if (avi->fsize <= 0 || avi->fsize < avi->riff_end)
408  avi->fsize = avi->riff_end == 8 ? INT64_MAX : avi->riff_end;
409 
410  /* first list tag */
411  stream_index = -1;
412  codec_type = -1;
413  frame_period = 0;
414  for (;;) {
415  if (url_feof(pb))
416  goto fail;
417  tag = avio_rl32(pb);
418  size = avio_rl32(pb);
419 
420  print_tag("tag", tag, size);
421 
422  switch (tag) {
423  case MKTAG('L', 'I', 'S', 'T'):
424  list_end = avio_tell(pb) + size;
425  /* Ignored, except at start of video packets. */
426  tag1 = avio_rl32(pb);
427 
428  print_tag("list", tag1, 0);
429 
430  if (tag1 == MKTAG('m', 'o', 'v', 'i')) {
431  avi->movi_list = avio_tell(pb) - 4;
432  if (size)
433  avi->movi_end = avi->movi_list + size + (size & 1);
434  else
435  avi->movi_end = avi->fsize;
436  av_dlog(NULL, "movi end=%"PRIx64"\n", avi->movi_end);
437  goto end_of_header;
438  } else if (tag1 == MKTAG('I', 'N', 'F', 'O'))
439  ff_read_riff_info(s, size - 4);
440  else if (tag1 == MKTAG('n', 'c', 'd', 't'))
441  avi_read_nikon(s, list_end);
442 
443  break;
444  case MKTAG('I', 'D', 'I', 'T'):
445  {
446  unsigned char date[64] = { 0 };
447  size += (size & 1);
448  size -= avio_read(pb, date, FFMIN(size, sizeof(date) - 1));
449  avio_skip(pb, size);
450  avi_metadata_creation_time(&s->metadata, date);
451  break;
452  }
453  case MKTAG('d', 'm', 'l', 'h'):
454  avi->is_odml = 1;
455  avio_skip(pb, size + (size & 1));
456  break;
457  case MKTAG('a', 'm', 'v', 'h'):
458  amv_file_format = 1;
459  case MKTAG('a', 'v', 'i', 'h'):
460  /* AVI header */
461  /* using frame_period is bad idea */
462  frame_period = avio_rl32(pb);
463  avio_rl32(pb); /* max. bytes per second */
464  avio_rl32(pb);
465  avi->non_interleaved |= avio_rl32(pb) & AVIF_MUSTUSEINDEX;
466 
467  avio_skip(pb, 2 * 4);
468  avio_rl32(pb);
469  avio_rl32(pb);
470  avih_width = avio_rl32(pb);
471  avih_height = avio_rl32(pb);
472 
473  avio_skip(pb, size - 10 * 4);
474  break;
475  case MKTAG('s', 't', 'r', 'h'):
476  /* stream header */
477 
478  tag1 = avio_rl32(pb);
479  handler = avio_rl32(pb); /* codec tag */
480 
481  if (tag1 == MKTAG('p', 'a', 'd', 's')) {
482  avio_skip(pb, size - 8);
483  break;
484  } else {
485  stream_index++;
486  st = avformat_new_stream(s, NULL);
487  if (!st)
488  goto fail;
489 
490  st->id = stream_index;
491  ast = av_mallocz(sizeof(AVIStream));
492  if (!ast)
493  goto fail;
494  st->priv_data = ast;
495  }
496  if (amv_file_format)
497  tag1 = stream_index ? MKTAG('a', 'u', 'd', 's')
498  : MKTAG('v', 'i', 'd', 's');
499 
500  print_tag("strh", tag1, -1);
501 
502  if (tag1 == MKTAG('i', 'a', 'v', 's') ||
503  tag1 == MKTAG('i', 'v', 'a', 's')) {
504  int64_t dv_dur;
505 
506  /* After some consideration -- I don't think we
507  * have to support anything but DV in type1 AVIs. */
508  if (s->nb_streams != 1)
509  goto fail;
510 
511  if (handler != MKTAG('d', 'v', 's', 'd') &&
512  handler != MKTAG('d', 'v', 'h', 'd') &&
513  handler != MKTAG('d', 'v', 's', 'l'))
514  goto fail;
515 
516  ast = s->streams[0]->priv_data;
517  av_freep(&s->streams[0]->codec->extradata);
518  av_freep(&s->streams[0]->codec);
519  if (s->streams[0]->info)
520  av_freep(&s->streams[0]->info->duration_error);
521  av_freep(&s->streams[0]->info);
522  av_freep(&s->streams[0]);
523  s->nb_streams = 0;
524  if (CONFIG_DV_DEMUXER) {
525  avi->dv_demux = avpriv_dv_init_demux(s);
526  if (!avi->dv_demux)
527  goto fail;
528  } else
529  goto fail;
530  s->streams[0]->priv_data = ast;
531  avio_skip(pb, 3 * 4);
532  ast->scale = avio_rl32(pb);
533  ast->rate = avio_rl32(pb);
534  avio_skip(pb, 4); /* start time */
535 
536  dv_dur = avio_rl32(pb);
537  if (ast->scale > 0 && ast->rate > 0 && dv_dur > 0) {
538  dv_dur *= AV_TIME_BASE;
539  s->duration = av_rescale(dv_dur, ast->scale, ast->rate);
540  }
541  /* else, leave duration alone; timing estimation in utils.c
542  * will make a guess based on bitrate. */
543 
544  stream_index = s->nb_streams - 1;
545  avio_skip(pb, size - 9 * 4);
546  break;
547  }
548 
549  av_assert0(stream_index < s->nb_streams);
550  st->codec->stream_codec_tag = handler;
551 
552  avio_rl32(pb); /* flags */
553  avio_rl16(pb); /* priority */
554  avio_rl16(pb); /* language */
555  avio_rl32(pb); /* initial frame */
556  ast->scale = avio_rl32(pb);
557  ast->rate = avio_rl32(pb);
558  if (!(ast->scale && ast->rate)) {
559  av_log(s, AV_LOG_WARNING,
560  "scale/rate is %u/%u which is invalid. "
561  "(This file has been generated by broken software.)\n",
562  ast->scale,
563  ast->rate);
564  if (frame_period) {
565  ast->rate = 1000000;
566  ast->scale = frame_period;
567  } else {
568  ast->rate = 25;
569  ast->scale = 1;
570  }
571  }
572  avpriv_set_pts_info(st, 64, ast->scale, ast->rate);
573 
574  ast->cum_len = avio_rl32(pb); /* start */
575  st->nb_frames = avio_rl32(pb);
576 
577  st->start_time = 0;
578  avio_rl32(pb); /* buffer size */
579  avio_rl32(pb); /* quality */
580  if (ast->cum_len*ast->scale/ast->rate > 3600) {
581  av_log(s, AV_LOG_ERROR, "crazy start time, iam scared, giving up\n");
582  return AVERROR_INVALIDDATA;
583  }
584  ast->sample_size = avio_rl32(pb); /* sample ssize */
585  ast->cum_len *= FFMAX(1, ast->sample_size);
586  av_dlog(s, "%"PRIu32" %"PRIu32" %d\n",
587  ast->rate, ast->scale, ast->sample_size);
588 
589  switch (tag1) {
590  case MKTAG('v', 'i', 'd', 's'):
591  codec_type = AVMEDIA_TYPE_VIDEO;
592 
593  ast->sample_size = 0;
594  break;
595  case MKTAG('a', 'u', 'd', 's'):
596  codec_type = AVMEDIA_TYPE_AUDIO;
597  break;
598  case MKTAG('t', 'x', 't', 's'):
599  codec_type = AVMEDIA_TYPE_SUBTITLE;
600  break;
601  case MKTAG('d', 'a', 't', 's'):
602  codec_type = AVMEDIA_TYPE_DATA;
603  break;
604  default:
605  av_log(s, AV_LOG_INFO, "unknown stream type %X\n", tag1);
606  }
607  if (ast->sample_size == 0) {
608  st->duration = st->nb_frames;
609  if (st->duration > 0 && avi->io_fsize > 0 && avi->riff_end > avi->io_fsize) {
610  av_log(s, AV_LOG_DEBUG, "File is truncated adjusting duration\n");
611  st->duration = av_rescale(st->duration, avi->io_fsize, avi->riff_end);
612  }
613  }
614  ast->frame_offset = ast->cum_len;
615  avio_skip(pb, size - 12 * 4);
616  break;
617  case MKTAG('s', 't', 'r', 'f'):
618  /* stream header */
619  if (!size)
620  break;
621  if (stream_index >= (unsigned)s->nb_streams || avi->dv_demux) {
622  avio_skip(pb, size);
623  } else {
624  uint64_t cur_pos = avio_tell(pb);
625  unsigned esize;
626  if (cur_pos < list_end)
627  size = FFMIN(size, list_end - cur_pos);
628  st = s->streams[stream_index];
629  if (st->codec->codec_type != AVMEDIA_TYPE_UNKNOWN) {
630  avio_skip(pb, size);
631  break;
632  }
633  switch (codec_type) {
634  case AVMEDIA_TYPE_VIDEO:
635  if (amv_file_format) {
636  st->codec->width = avih_width;
637  st->codec->height = avih_height;
638  st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
639  st->codec->codec_id = AV_CODEC_ID_AMV;
640  avio_skip(pb, size);
641  break;
642  }
643  tag1 = ff_get_bmp_header(pb, st, &esize);
644 
645  if (tag1 == MKTAG('D', 'X', 'S', 'B') ||
646  tag1 == MKTAG('D', 'X', 'S', 'A')) {
647  st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
648  st->codec->codec_tag = tag1;
649  st->codec->codec_id = AV_CODEC_ID_XSUB;
650  break;
651  }
652 
653  if (size > 10 * 4 && size < (1 << 30) && size < avi->fsize) {
654  if (esize == size-1 && (esize&1)) {
655  st->codec->extradata_size = esize - 10 * 4;
656  } else
657  st->codec->extradata_size = size - 10 * 4;
658  if (ff_get_extradata(st->codec, pb, st->codec->extradata_size) < 0)
659  return AVERROR(ENOMEM);
660  }
661 
662  // FIXME: check if the encoder really did this correctly
663  if (st->codec->extradata_size & 1)
664  avio_r8(pb);
665 
666  /* Extract palette from extradata if bpp <= 8.
667  * This code assumes that extradata contains only palette.
668  * This is true for all paletted codecs implemented in
669  * FFmpeg. */
670  if (st->codec->extradata_size &&
671  (st->codec->bits_per_coded_sample <= 8)) {
672  int pal_size = (1 << st->codec->bits_per_coded_sample) << 2;
673  const uint8_t *pal_src;
674 
675  pal_size = FFMIN(pal_size, st->codec->extradata_size);
676  pal_src = st->codec->extradata +
677  st->codec->extradata_size - pal_size;
678  for (i = 0; i < pal_size / 4; i++)
679  ast->pal[i] = 0xFFU<<24 | AV_RL32(pal_src+4*i);
680  ast->has_pal = 1;
681  }
682 
683  print_tag("video", tag1, 0);
684 
685  st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
686  st->codec->codec_tag = tag1;
687  st->codec->codec_id = ff_codec_get_id(ff_codec_bmp_tags,
688  tag1);
689  /* This is needed to get the pict type which is necessary
690  * for generating correct pts. */
691  st->need_parsing = AVSTREAM_PARSE_HEADERS;
692  if (st->codec->codec_tag == MKTAG('V', 'S', 'S', 'H'))
693  st->need_parsing = AVSTREAM_PARSE_FULL;
694 
695  if (st->codec->codec_tag == 0 && st->codec->height > 0 &&
696  st->codec->extradata_size < 1U << 30) {
697  st->codec->extradata_size += 9;
698  if ((ret = av_reallocp(&st->codec->extradata,
699  st->codec->extradata_size +
700  FF_INPUT_BUFFER_PADDING_SIZE)) < 0) {
701  st->codec->extradata_size = 0;
702  return ret;
703  } else
704  memcpy(st->codec->extradata + st->codec->extradata_size - 9,
705  "BottomUp", 9);
706  }
707  st->codec->height = FFABS(st->codec->height);
708 
709 // avio_skip(pb, size - 5 * 4);
710  break;
711  case AVMEDIA_TYPE_AUDIO:
712  ret = ff_get_wav_header(pb, st->codec, size);
713  if (ret < 0)
714  return ret;
715  ast->dshow_block_align = st->codec->block_align;
716  if (ast->sample_size && st->codec->block_align &&
717  ast->sample_size != st->codec->block_align) {
718  av_log(s,
719  AV_LOG_WARNING,
720  "sample size (%d) != block align (%d)\n",
721  ast->sample_size,
722  st->codec->block_align);
723  ast->sample_size = st->codec->block_align;
724  }
725  /* 2-aligned
726  * (fix for Stargate SG-1 - 3x18 - Shades of Grey.avi) */
727  if (size & 1)
728  avio_skip(pb, 1);
729  /* Force parsing as several audio frames can be in
730  * one packet and timestamps refer to packet start. */
731  st->need_parsing = AVSTREAM_PARSE_TIMESTAMPS;
732  /* ADTS header is in extradata, AAC without header must be
733  * stored as exact frames. Parser not needed and it will
734  * fail. */
735  if (st->codec->codec_id == AV_CODEC_ID_AAC &&
736  st->codec->extradata_size)
737  st->need_parsing = AVSTREAM_PARSE_NONE;
738  /* AVI files with Xan DPCM audio (wrongly) declare PCM
739  * audio in the header but have Axan as stream_code_tag. */
740  if (st->codec->stream_codec_tag == AV_RL32("Axan")) {
741  st->codec->codec_id = AV_CODEC_ID_XAN_DPCM;
742  st->codec->codec_tag = 0;
743  ast->dshow_block_align = 0;
744  }
745  if (amv_file_format) {
746  st->codec->codec_id = AV_CODEC_ID_ADPCM_IMA_AMV;
747  ast->dshow_block_align = 0;
748  }
749  if (st->codec->codec_id == AV_CODEC_ID_AAC && ast->dshow_block_align <= 4 && ast->dshow_block_align) {
750  av_log(s, AV_LOG_DEBUG, "overriding invalid dshow_block_align of %d\n", ast->dshow_block_align);
751  ast->dshow_block_align = 0;
752  }
753  if (st->codec->codec_id == AV_CODEC_ID_AAC && ast->dshow_block_align == 1024 && ast->sample_size == 1024 ||
754  st->codec->codec_id == AV_CODEC_ID_AAC && ast->dshow_block_align == 4096 && ast->sample_size == 4096 ||
755  st->codec->codec_id == AV_CODEC_ID_MP3 && ast->dshow_block_align == 1152 && ast->sample_size == 1152) {
756  av_log(s, AV_LOG_DEBUG, "overriding sample_size\n");
757  ast->sample_size = 0;
758  }
759  break;
760  case AVMEDIA_TYPE_SUBTITLE:
761  st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
762  st->request_probe= 1;
763  avio_skip(pb, size);
764  break;
765  default:
766  st->codec->codec_type = AVMEDIA_TYPE_DATA;
767  st->codec->codec_id = AV_CODEC_ID_NONE;
768  st->codec->codec_tag = 0;
769  avio_skip(pb, size);
770  break;
771  }
772  }
773  break;
774  case MKTAG('s', 't', 'r', 'd'):
775  if (stream_index >= (unsigned)s->nb_streams
776  || s->streams[stream_index]->codec->extradata_size
777  || s->streams[stream_index]->codec->codec_tag == MKTAG('H','2','6','4')) {
778  avio_skip(pb, size);
779  } else {
780  uint64_t cur_pos = avio_tell(pb);
781  if (cur_pos < list_end)
782  size = FFMIN(size, list_end - cur_pos);
783  st = s->streams[stream_index];
784 
785  if (size<(1<<30)) {
786  if (ff_get_extradata(st->codec, pb, size) < 0)
787  return AVERROR(ENOMEM);
788  }
789 
790  if (st->codec->extradata_size & 1) //FIXME check if the encoder really did this correctly
791  avio_r8(pb);
792  }
793  break;
794  case MKTAG('i', 'n', 'd', 'x'):
795  i = avio_tell(pb);
796  if (pb->seekable && !(s->flags & AVFMT_FLAG_IGNIDX) &&
797  avi->use_odml &&
798  read_braindead_odml_indx(s, 0) < 0 &&
799  (s->error_recognition & AV_EF_EXPLODE))
800  goto fail;
801  avio_seek(pb, i + size, SEEK_SET);
802  break;
803  case MKTAG('v', 'p', 'r', 'p'):
804  if (stream_index < (unsigned)s->nb_streams && size > 9 * 4) {
805  AVRational active, active_aspect;
806 
807  st = s->streams[stream_index];
808  avio_rl32(pb);
809  avio_rl32(pb);
810  avio_rl32(pb);
811  avio_rl32(pb);
812  avio_rl32(pb);
813 
814  active_aspect.den = avio_rl16(pb);
815  active_aspect.num = avio_rl16(pb);
816  active.num = avio_rl32(pb);
817  active.den = avio_rl32(pb);
818  avio_rl32(pb); // nbFieldsPerFrame
819 
820  if (active_aspect.num && active_aspect.den &&
821  active.num && active.den) {
822  st->sample_aspect_ratio = av_div_q(active_aspect, active);
823  av_dlog(s, "vprp %d/%d %d/%d\n",
824  active_aspect.num, active_aspect.den,
825  active.num, active.den);
826  }
827  size -= 9 * 4;
828  }
829  avio_skip(pb, size);
830  break;
831  case MKTAG('s', 't', 'r', 'n'):
832  if (s->nb_streams) {
833  ret = avi_read_tag(s, s->streams[s->nb_streams - 1], tag, size);
834  if (ret < 0)
835  return ret;
836  break;
837  }
838  default:
839  if (size > 1000000) {
840  av_log(s, AV_LOG_ERROR,
841  "Something went wrong during header parsing, "
842  "I will ignore it and try to continue anyway.\n");
843  if (s->error_recognition & AV_EF_EXPLODE)
844  goto fail;
845  avi->movi_list = avio_tell(pb) - 4;
846  avi->movi_end = avi->fsize;
847  goto end_of_header;
848  }
849  /* skip tag */
850  size += (size & 1);
851  avio_skip(pb, size);
852  break;
853  }
854  }
855 
856 end_of_header:
857  /* check stream number */
858  if (stream_index != s->nb_streams - 1) {
859 
860 fail:
861  return AVERROR_INVALIDDATA;
862  }
863 
864  if (!avi->index_loaded && pb->seekable)
865  avi_load_index(s);
866  avi->index_loaded |= 1;
867  avi->non_interleaved |= guess_ni_flag(s) | (s->flags & AVFMT_FLAG_SORT_DTS);
868 
869  dict_entry = av_dict_get(s->metadata, "ISFT", NULL, 0);
870  if (dict_entry && !strcmp(dict_entry->value, "PotEncoder"))
871  for (i = 0; i < s->nb_streams; i++) {
872  AVStream *st = s->streams[i];
873  if ( st->codec->codec_id == AV_CODEC_ID_MPEG1VIDEO
874  || st->codec->codec_id == AV_CODEC_ID_MPEG2VIDEO)
875  st->need_parsing = AVSTREAM_PARSE_FULL;
876  }
877 
878  for (i = 0; i < s->nb_streams; i++) {
879  AVStream *st = s->streams[i];
880  if (st->nb_index_entries)
881  break;
882  }
883  // DV-in-AVI cannot be non-interleaved, if set this must be
884  // a mis-detection.
885  if (avi->dv_demux)
886  avi->non_interleaved = 0;
887  if (i == s->nb_streams && avi->non_interleaved) {
888  av_log(s, AV_LOG_WARNING,
889  "Non-interleaved AVI without index, switching to interleaved\n");
890  avi->non_interleaved = 0;
891  }
892 
893  if (avi->non_interleaved) {
894  av_log(s, AV_LOG_INFO, "non-interleaved AVI\n");
895  clean_index(s);
896  }
897 
898  ff_metadata_conv_ctx(s, NULL, avi_metadata_conv);
899  ff_metadata_conv_ctx(s, NULL, ff_riff_info_conv);
900 
901  return 0;
902 }
903 
904 static int read_gab2_sub(AVStream *st, AVPacket *pkt)
905 {
906  if (pkt->size >= 7 &&
907  !strcmp(pkt->data, "GAB2") && AV_RL16(pkt->data + 5) == 2) {
908  uint8_t desc[256];
909  int score = AVPROBE_SCORE_EXTENSION, ret;
910  AVIStream *ast = st->priv_data;
911  AVInputFormat *sub_demuxer;
912  AVRational time_base;
913  AVIOContext *pb = avio_alloc_context(pkt->data + 7,
914  pkt->size - 7,
915  0, NULL, NULL, NULL, NULL);
916  AVProbeData pd;
917  unsigned int desc_len = avio_rl32(pb);
918 
919  if (desc_len > pb->buf_end - pb->buf_ptr)
920  goto error;
921 
922  ret = avio_get_str16le(pb, desc_len, desc, sizeof(desc));
923  avio_skip(pb, desc_len - ret);
924  if (*desc)
925  av_dict_set(&st->metadata, "title", desc, 0);
926 
927  avio_rl16(pb); /* flags? */
928  avio_rl32(pb); /* data size */
929 
930  pd = (AVProbeData) { .buf = pb->buf_ptr,
931  .buf_size = pb->buf_end - pb->buf_ptr };
932  if (!(sub_demuxer = av_probe_input_format2(&pd, 1, &score)))
933  goto error;
934 
935  if (!(ast->sub_ctx = avformat_alloc_context()))
936  goto error;
937 
938  ast->sub_ctx->pb = pb;
939  if (!avformat_open_input(&ast->sub_ctx, "", sub_demuxer, NULL)) {
940  ff_read_packet(ast->sub_ctx, &ast->sub_pkt);
941  *st->codec = *ast->sub_ctx->streams[0]->codec;
942  ast->sub_ctx->streams[0]->codec->extradata = NULL;
943  time_base = ast->sub_ctx->streams[0]->time_base;
944  avpriv_set_pts_info(st, 64, time_base.num, time_base.den);
945  }
946  ast->sub_buffer = pkt->data;
947  memset(pkt, 0, sizeof(*pkt));
948  return 1;
949 
950 error:
951  av_freep(&pb);
952  }
953  return 0;
954 }
955 
956 static AVStream *get_subtitle_pkt(AVFormatContext *s, AVStream *next_st,
957  AVPacket *pkt)
958 {
959  AVIStream *ast, *next_ast = next_st->priv_data;
960  int64_t ts, next_ts, ts_min = INT64_MAX;
961  AVStream *st, *sub_st = NULL;
962  int i;
963 
964  next_ts = av_rescale_q(next_ast->frame_offset, next_st->time_base,
965  AV_TIME_BASE_Q);
966 
967  for (i = 0; i < s->nb_streams; i++) {
968  st = s->streams[i];
969  ast = st->priv_data;
970  if (st->discard < AVDISCARD_ALL && ast && ast->sub_pkt.data) {
971  ts = av_rescale_q(ast->sub_pkt.dts, st->time_base, AV_TIME_BASE_Q);
972  if (ts <= next_ts && ts < ts_min) {
973  ts_min = ts;
974  sub_st = st;
975  }
976  }
977  }
978 
979  if (sub_st) {
980  ast = sub_st->priv_data;
981  *pkt = ast->sub_pkt;
982  pkt->stream_index = sub_st->index;
983 
984  if (ff_read_packet(ast->sub_ctx, &ast->sub_pkt) < 0)
985  ast->sub_pkt.data = NULL;
986  }
987  return sub_st;
988 }
989 
990 static int get_stream_idx(unsigned *d)
991 {
992  if (d[0] >= '0' && d[0] <= '9' &&
993  d[1] >= '0' && d[1] <= '9') {
994  return (d[0] - '0') * 10 + (d[1] - '0');
995  } else {
996  return 100; // invalid stream ID
997  }
998 }
999 
1000 /**
1001  *
1002  * @param exit_early set to 1 to just gather packet position without making the changes needed to actually read & return the packet
1003  */
1004 static int avi_sync(AVFormatContext *s, int exit_early)
1005 {
1006  AVIContext *avi = s->priv_data;
1007  AVIOContext *pb = s->pb;
1008  int n;
1009  unsigned int d[8];
1010  unsigned int size;
1011  int64_t i, sync;
1012 
1013 start_sync:
1014  memset(d, -1, sizeof(d));
1015  for (i = sync = avio_tell(pb); !url_feof(pb); i++) {
1016  int j;
1017 
1018  for (j = 0; j < 7; j++)
1019  d[j] = d[j + 1];
1020  d[7] = avio_r8(pb);
1021 
1022  size = d[4] + (d[5] << 8) + (d[6] << 16) + (d[7] << 24);
1023 
1024  n = get_stream_idx(d + 2);
1025  av_dlog(s, "%X %X %X %X %X %X %X %X %"PRId64" %u %d\n",
1026  d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7], i, size, n);
1027  if (i*(avi->io_fsize>0) + (uint64_t)size > avi->fsize || d[0] > 127)
1028  continue;
1029 
1030  // parse ix##
1031  if ((d[0] == 'i' && d[1] == 'x' && n < s->nb_streams) ||
1032  // parse JUNK
1033  (d[0] == 'J' && d[1] == 'U' && d[2] == 'N' && d[3] == 'K') ||
1034  (d[0] == 'i' && d[1] == 'd' && d[2] == 'x' && d[3] == '1')) {
1035  avio_skip(pb, size);
1036  goto start_sync;
1037  }
1038 
1039  // parse stray LIST
1040  if (d[0] == 'L' && d[1] == 'I' && d[2] == 'S' && d[3] == 'T') {
1041  avio_skip(pb, 4);
1042  goto start_sync;
1043  }
1044 
1045  n = avi->dv_demux ? 0 : get_stream_idx(d);
1046 
1047  if (!((i - avi->last_pkt_pos) & 1) &&
1048  get_stream_idx(d + 1) < s->nb_streams)
1049  continue;
1050 
1051  // detect ##ix chunk and skip
1052  if (d[2] == 'i' && d[3] == 'x' && n < s->nb_streams) {
1053  avio_skip(pb, size);
1054  goto start_sync;
1055  }
1056 
1057  // parse ##dc/##wb
1058  if (n < s->nb_streams) {
1059  AVStream *st;
1060  AVIStream *ast;
1061  st = s->streams[n];
1062  ast = st->priv_data;
1063 
1064  if (!ast) {
1065  av_log(s, AV_LOG_WARNING, "Skiping foreign stream %d packet\n", n);
1066  continue;
1067  }
1068 
1069  if (s->nb_streams >= 2) {
1070  AVStream *st1 = s->streams[1];
1071  AVIStream *ast1 = st1->priv_data;
1072  // workaround for broken small-file-bug402.avi
1073  if ( d[2] == 'w' && d[3] == 'b'
1074  && n == 0
1075  && st ->codec->codec_type == AVMEDIA_TYPE_VIDEO
1076  && st1->codec->codec_type == AVMEDIA_TYPE_AUDIO
1077  && ast->prefix == 'd'*256+'c'
1078  && (d[2]*256+d[3] == ast1->prefix || !ast1->prefix_count)
1079  ) {
1080  n = 1;
1081  st = st1;
1082  ast = ast1;
1083  av_log(s, AV_LOG_WARNING,
1084  "Invalid stream + prefix combination, assuming audio.\n");
1085  }
1086  }
1087 
1088  if (!avi->dv_demux &&
1089  ((st->discard >= AVDISCARD_DEFAULT && size == 0) /* ||
1090  // FIXME: needs a little reordering
1091  (st->discard >= AVDISCARD_NONKEY &&
1092  !(pkt->flags & AV_PKT_FLAG_KEY)) */
1093  || st->discard >= AVDISCARD_ALL)) {
1094  if (!exit_early) {
1095  ast->frame_offset += get_duration(ast, size);
1096  avio_skip(pb, size);
1097  goto start_sync;
1098  }
1099  }
1100 
1101  if (d[2] == 'p' && d[3] == 'c' && size <= 4 * 256 + 4) {
1102  int k = avio_r8(pb);
1103  int last = (k + avio_r8(pb) - 1) & 0xFF;
1104 
1105  avio_rl16(pb); // flags
1106 
1107  // b + (g << 8) + (r << 16);
1108  for (; k <= last; k++)
1109  ast->pal[k] = 0xFFU<<24 | avio_rb32(pb)>>8;
1110 
1111  ast->has_pal = 1;
1112  goto start_sync;
1113  } else if (((ast->prefix_count < 5 || sync + 9 > i) &&
1114  d[2] < 128 && d[3] < 128) ||
1115  d[2] * 256 + d[3] == ast->prefix /* ||
1116  (d[2] == 'd' && d[3] == 'c') ||
1117  (d[2] == 'w' && d[3] == 'b') */) {
1118  if (exit_early)
1119  return 0;
1120  if (d[2] * 256 + d[3] == ast->prefix)
1121  ast->prefix_count++;
1122  else {
1123  ast->prefix = d[2] * 256 + d[3];
1124  ast->prefix_count = 0;
1125  }
1126 
1127  avi->stream_index = n;
1128  ast->packet_size = size + 8;
1129  ast->remaining = size;
1130 
1131  if (size || !ast->sample_size) {
1132  uint64_t pos = avio_tell(pb) - 8;
1133  if (!st->index_entries || !st->nb_index_entries ||
1134  st->index_entries[st->nb_index_entries - 1].pos < pos) {
1135  av_add_index_entry(st, pos, ast->frame_offset, size,
1136  0, AVINDEX_KEYFRAME);
1137  }
1138  }
1139  return 0;
1140  }
1141  }
1142  }
1143 
1144  if (pb->error)
1145  return pb->error;
1146  return AVERROR_EOF;
1147 }
1148 
1149 static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)
1150 {
1151  AVIContext *avi = s->priv_data;
1152  AVIOContext *pb = s->pb;
1153  int err;
1154 #if FF_API_DESTRUCT_PACKET
1155  void *dstr;
1156 #endif
1157 
1158  if (CONFIG_DV_DEMUXER && avi->dv_demux) {
1159  int size = avpriv_dv_get_packet(avi->dv_demux, pkt);
1160  if (size >= 0)
1161  return size;
1162  else
1163  goto resync;
1164  }
1165 
1166  if (avi->non_interleaved) {
1167  int best_stream_index = 0;
1168  AVStream *best_st = NULL;
1169  AVIStream *best_ast;
1170  int64_t best_ts = INT64_MAX;
1171  int i;
1172 
1173  for (i = 0; i < s->nb_streams; i++) {
1174  AVStream *st = s->streams[i];
1175  AVIStream *ast = st->priv_data;
1176  int64_t ts = ast->frame_offset;
1177  int64_t last_ts;
1178 
1179  if (!st->nb_index_entries)
1180  continue;
1181 
1182  last_ts = st->index_entries[st->nb_index_entries - 1].timestamp;
1183  if (!ast->remaining && ts > last_ts)
1184  continue;
1185 
1186  ts = av_rescale_q(ts, st->time_base,
1187  (AVRational) { FFMAX(1, ast->sample_size),
1188  AV_TIME_BASE });
1189 
1190  av_dlog(s, "%"PRId64" %d/%d %"PRId64"\n", ts,
1191  st->time_base.num, st->time_base.den, ast->frame_offset);
1192  if (ts < best_ts) {
1193  best_ts = ts;
1194  best_st = st;
1195  best_stream_index = i;
1196  }
1197  }
1198  if (!best_st)
1199  return AVERROR_EOF;
1200 
1201  best_ast = best_st->priv_data;
1202  best_ts = best_ast->frame_offset;
1203  if (best_ast->remaining) {
1204  i = av_index_search_timestamp(best_st,
1205  best_ts,
1206  AVSEEK_FLAG_ANY |
1207  AVSEEK_FLAG_BACKWARD);
1208  } else {
1209  i = av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY);
1210  if (i >= 0)
1211  best_ast->frame_offset = best_st->index_entries[i].timestamp;
1212  }
1213 
1214  if (i >= 0) {
1215  int64_t pos = best_st->index_entries[i].pos;
1216  pos += best_ast->packet_size - best_ast->remaining;
1217  if (avio_seek(s->pb, pos + 8, SEEK_SET) < 0)
1218  return AVERROR_EOF;
1219 
1220  av_assert0(best_ast->remaining <= best_ast->packet_size);
1221 
1222  avi->stream_index = best_stream_index;
1223  if (!best_ast->remaining)
1224  best_ast->packet_size =
1225  best_ast->remaining = best_st->index_entries[i].size;
1226  }
1227  else
1228  return AVERROR_EOF;
1229  }
1230 
1231 resync:
1232  if (avi->stream_index >= 0) {
1233  AVStream *st = s->streams[avi->stream_index];
1234  AVIStream *ast = st->priv_data;
1235  int size, err;
1236 
1237  if (get_subtitle_pkt(s, st, pkt))
1238  return 0;
1239 
1240  // minorityreport.AVI block_align=1024 sample_size=1 IMA-ADPCM
1241  if (ast->sample_size <= 1)
1242  size = INT_MAX;
1243  else if (ast->sample_size < 32)
1244  // arbitrary multiplier to avoid tiny packets for raw PCM data
1245  size = 1024 * ast->sample_size;
1246  else
1247  size = ast->sample_size;
1248 
1249  if (size > ast->remaining)
1250  size = ast->remaining;
1251  avi->last_pkt_pos = avio_tell(pb);
1252  err = av_get_packet(pb, pkt, size);
1253  if (err < 0)
1254  return err;
1255  size = err;
1256 
1257  if (ast->has_pal && pkt->size < (unsigned)INT_MAX / 2) {
1258  uint8_t *pal;
1259  pal = av_packet_new_side_data(pkt,
1260  AV_PKT_DATA_PALETTE,
1261  AVPALETTE_SIZE);
1262  if (!pal) {
1263  av_log(s, AV_LOG_ERROR,
1264  "Failed to allocate data for palette\n");
1265  } else {
1266  memcpy(pal, ast->pal, AVPALETTE_SIZE);
1267  ast->has_pal = 0;
1268  }
1269  }
1270 
1271  if (CONFIG_DV_DEMUXER && avi->dv_demux) {
1272  AVBufferRef *avbuf = pkt->buf;
1273 #if FF_API_DESTRUCT_PACKET
1274 FF_DISABLE_DEPRECATION_WARNINGS
1275  dstr = pkt->destruct;
1276 FF_ENABLE_DEPRECATION_WARNINGS
1277 #endif
1278  size = avpriv_dv_produce_packet(avi->dv_demux, pkt,
1279  pkt->data, pkt->size, pkt->pos);
1280 #if FF_API_DESTRUCT_PACKET
1281 FF_DISABLE_DEPRECATION_WARNINGS
1282  pkt->destruct = dstr;
1283 FF_ENABLE_DEPRECATION_WARNINGS
1284 #endif
1285  pkt->buf = avbuf;
1286  pkt->flags |= AV_PKT_FLAG_KEY;
1287  if (size < 0)
1288  av_free_packet(pkt);
1289  } else if (st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE &&
1290  !st->codec->codec_tag && read_gab2_sub(st, pkt)) {
1291  ast->frame_offset++;
1292  avi->stream_index = -1;
1293  ast->remaining = 0;
1294  goto resync;
1295  } else {
1296  /* XXX: How to handle B-frames in AVI? */
1297  pkt->dts = ast->frame_offset;
1298 // pkt->dts += ast->start;
1299  if (ast->sample_size)
1300  pkt->dts /= ast->sample_size;
1301  av_dlog(s,
1302  "dts:%"PRId64" offset:%"PRId64" %d/%d smpl_siz:%d "
1303  "base:%d st:%d size:%d\n",
1304  pkt->dts,
1305  ast->frame_offset,
1306  ast->scale,
1307  ast->rate,
1308  ast->sample_size,
1309  AV_TIME_BASE,
1310  avi->stream_index,
1311  size);
1312  pkt->stream_index = avi->stream_index;
1313 
1314  if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO && st->index_entries) {
1315  AVIndexEntry *e;
1316  int index;
1317 
1318  index = av_index_search_timestamp(st, ast->frame_offset, 0);
1319  e = &st->index_entries[index];
1320 
1321  if (index >= 0 && e->timestamp == ast->frame_offset) {
1322  if (index == st->nb_index_entries-1) {
1323  int key=1;
1324  int i;
1325  uint32_t state=-1;
1326  for (i=0; i<FFMIN(size,256); i++) {
1327  if (st->codec->codec_id == AV_CODEC_ID_MPEG4) {
1328  if (state == 0x1B6) {
1329  key= !(pkt->data[i]&0xC0);
1330  break;
1331  }
1332  }else
1333  break;
1334  state= (state<<8) + pkt->data[i];
1335  }
1336  if (!key)
1337  e->flags &= ~AVINDEX_KEYFRAME;
1338  }
1339  if (e->flags & AVINDEX_KEYFRAME)
1340  pkt->flags |= AV_PKT_FLAG_KEY;
1341  }
1342  } else {
1343  pkt->flags |= AV_PKT_FLAG_KEY;
1344  }
1345  ast->frame_offset += get_duration(ast, pkt->size);
1346  }
1347  ast->remaining -= err;
1348  if (!ast->remaining) {
1349  avi->stream_index = -1;
1350  ast->packet_size = 0;
1351  }
1352 
1353  if (!avi->non_interleaved && pkt->pos >= 0 && ast->seek_pos > pkt->pos) {
1354  av_free_packet(pkt);
1355  goto resync;
1356  }
1357  ast->seek_pos= 0;
1358 
1359  if (!avi->non_interleaved && st->nb_index_entries>1 && avi->index_loaded>1) {
1360  int64_t dts= av_rescale_q(pkt->dts, st->time_base, AV_TIME_BASE_Q);
1361 
1362  if (avi->dts_max - dts > 2*AV_TIME_BASE) {
1363  avi->non_interleaved= 1;
1364  av_log(s, AV_LOG_INFO, "Switching to NI mode, due to poor interleaving\n");
1365  }else if (avi->dts_max < dts)
1366  avi->dts_max = dts;
1367  }
1368 
1369  return 0;
1370  }
1371 
1372  if ((err = avi_sync(s, 0)) < 0)
1373  return err;
1374  goto resync;
1375 }
1376 
1377 /* XXX: We make the implicit supposition that the positions are sorted
1378  * for each stream. */
1379 static int avi_read_idx1(AVFormatContext *s, int size)
1380 {
1381  AVIContext *avi = s->priv_data;
1382  AVIOContext *pb = s->pb;
1383  int nb_index_entries, i;
1384  AVStream *st;
1385  AVIStream *ast;
1386  unsigned int index, tag, flags, pos, len, first_packet = 1;
1387  unsigned last_pos = -1;
1388  unsigned last_idx = -1;
1389  int64_t idx1_pos, first_packet_pos = 0, data_offset = 0;
1390  int anykey = 0;
1391 
1392  nb_index_entries = size / 16;
1393  if (nb_index_entries <= 0)
1394  return AVERROR_INVALIDDATA;
1395 
1396  idx1_pos = avio_tell(pb);
1397  avio_seek(pb, avi->movi_list + 4, SEEK_SET);
1398  if (avi_sync(s, 1) == 0)
1399  first_packet_pos = avio_tell(pb) - 8;
1400  avi->stream_index = -1;
1401  avio_seek(pb, idx1_pos, SEEK_SET);
1402 
1403  if (s->nb_streams == 1 && s->streams[0]->codec->codec_tag == AV_RL32("MMES")) {
1404  first_packet_pos = 0;
1405  data_offset = avi->movi_list;
1406  }
1407 
1408  /* Read the entries and sort them in each stream component. */
1409  for (i = 0; i < nb_index_entries; i++) {
1410  if (url_feof(pb))
1411  return -1;
1412 
1413  tag = avio_rl32(pb);
1414  flags = avio_rl32(pb);
1415  pos = avio_rl32(pb);
1416  len = avio_rl32(pb);
1417  av_dlog(s, "%d: tag=0x%x flags=0x%x pos=0x%x len=%d/",
1418  i, tag, flags, pos, len);
1419 
1420  index = ((tag & 0xff) - '0') * 10;
1421  index += (tag >> 8 & 0xff) - '0';
1422  if (index >= s->nb_streams)
1423  continue;
1424  st = s->streams[index];
1425  ast = st->priv_data;
1426 
1427  if (first_packet && first_packet_pos) {
1428  data_offset = first_packet_pos - pos;
1429  first_packet = 0;
1430  }
1431  pos += data_offset;
1432 
1433  av_dlog(s, "%d cum_len=%"PRId64"\n", len, ast->cum_len);
1434 
1435  // even if we have only a single stream, we should
1436  // switch to non-interleaved to get correct timestamps
1437  if (last_pos == pos)
1438  avi->non_interleaved = 1;
1439  if (last_idx != pos && len) {
1440  av_add_index_entry(st, pos, ast->cum_len, len, 0,
1441  (flags & AVIIF_INDEX) ? AVINDEX_KEYFRAME : 0);
1442  last_idx= pos;
1443  }
1444  ast->cum_len += get_duration(ast, len);
1445  last_pos = pos;
1446  anykey |= flags&AVIIF_INDEX;
1447  }
1448  if (!anykey) {
1449  for (index = 0; index < s->nb_streams; index++) {
1450  st = s->streams[index];
1451  if (st->nb_index_entries)
1452  st->index_entries[0].flags |= AVINDEX_KEYFRAME;
1453  }
1454  }
1455  return 0;
1456 }
1457 
1458 static int guess_ni_flag(AVFormatContext *s)
1459 {
1460  int i;
1461  int64_t last_start = 0;
1462  int64_t first_end = INT64_MAX;
1463  int64_t oldpos = avio_tell(s->pb);
1464  int *idx;
1465  int64_t min_pos, pos;
1466 
1467  for (i = 0; i < s->nb_streams; i++) {
1468  AVStream *st = s->streams[i];
1469  int n = st->nb_index_entries;
1470  unsigned int size;
1471 
1472  if (n <= 0)
1473  continue;
1474 
1475  if (n >= 2) {
1476  int64_t pos = st->index_entries[0].pos;
1477  avio_seek(s->pb, pos + 4, SEEK_SET);
1478  size = avio_rl32(s->pb);
1479  if (pos + size > st->index_entries[1].pos)
1480  last_start = INT64_MAX;
1481  }
1482 
1483  if (st->index_entries[0].pos > last_start)
1484  last_start = st->index_entries[0].pos;
1485  if (st->index_entries[n - 1].pos < first_end)
1486  first_end = st->index_entries[n - 1].pos;
1487  }
1488  avio_seek(s->pb, oldpos, SEEK_SET);
1489  if (last_start > first_end)
1490  return 1;
1491  idx= av_calloc(s->nb_streams, sizeof(*idx));
1492  if (!idx)
1493  return 0;
1494  for (min_pos=pos=0; min_pos!=INT64_MAX; pos= min_pos+1LU) {
1495  int64_t max_dts = INT64_MIN/2, min_dts= INT64_MAX/2;
1496  min_pos = INT64_MAX;
1497 
1498  for (i=0; i<s->nb_streams; i++) {
1499  AVStream *st = s->streams[i];
1500  AVIStream *ast = st->priv_data;
1501  int n= st->nb_index_entries;
1502  while (idx[i]<n && st->index_entries[idx[i]].pos < pos)
1503  idx[i]++;
1504  if (idx[i] < n) {
1505  min_dts = FFMIN(min_dts, av_rescale_q(st->index_entries[idx[i]].timestamp/FFMAX(ast->sample_size, 1), st->time_base, AV_TIME_BASE_Q));
1506  min_pos = FFMIN(min_pos, st->index_entries[idx[i]].pos);
1507  }
1508  if (idx[i])
1509  max_dts = FFMAX(max_dts, av_rescale_q(st->index_entries[idx[i]-1].timestamp/FFMAX(ast->sample_size, 1), st->time_base, AV_TIME_BASE_Q));
1510  }
1511  if (max_dts - min_dts > 2*AV_TIME_BASE) {
1512  av_free(idx);
1513  return 1;
1514  }
1515  }
1516  av_free(idx);
1517  return 0;
1518 }
1519 
1520 static int avi_load_index(AVFormatContext *s)
1521 {
1522  AVIContext *avi = s->priv_data;
1523  AVIOContext *pb = s->pb;
1524  uint32_t tag, size;
1525  int64_t pos = avio_tell(pb);
1526  int64_t next;
1527  int ret = -1;
1528 
1529  if (avio_seek(pb, avi->movi_end, SEEK_SET) < 0)
1530  goto the_end; // maybe truncated file
1531  av_dlog(s, "movi_end=0x%"PRIx64"\n", avi->movi_end);
1532  for (;;) {
1533  tag = avio_rl32(pb);
1534  size = avio_rl32(pb);
1535  if (url_feof(pb))
1536  break;
1537  next = avio_tell(pb) + size + (size & 1);
1538 
1539  av_dlog(s, "tag=%c%c%c%c size=0x%x\n",
1540  tag & 0xff,
1541  (tag >> 8) & 0xff,
1542  (tag >> 16) & 0xff,
1543  (tag >> 24) & 0xff,
1544  size);
1545 
1546  if (tag == MKTAG('i', 'd', 'x', '1') &&
1547  avi_read_idx1(s, size) >= 0) {
1548  avi->index_loaded=2;
1549  ret = 0;
1550  }else if (tag == MKTAG('L', 'I', 'S', 'T')) {
1551  uint32_t tag1 = avio_rl32(pb);
1552 
1553  if (tag1 == MKTAG('I', 'N', 'F', 'O'))
1554  ff_read_riff_info(s, size - 4);
1555  }else if (!ret)
1556  break;
1557 
1558  if (avio_seek(pb, next, SEEK_SET) < 0)
1559  break; // something is wrong here
1560  }
1561 
1562 the_end:
1563  avio_seek(pb, pos, SEEK_SET);
1564  return ret;
1565 }
1566 
1567 static void seek_subtitle(AVStream *st, AVStream *st2, int64_t timestamp)
1568 {
1569  AVIStream *ast2 = st2->priv_data;
1570  int64_t ts2 = av_rescale_q(timestamp, st->time_base, st2->time_base);
1571  av_free_packet(&ast2->sub_pkt);
1572  if (avformat_seek_file(ast2->sub_ctx, 0, INT64_MIN, ts2, ts2, 0) >= 0 ||
1573  avformat_seek_file(ast2->sub_ctx, 0, ts2, ts2, INT64_MAX, 0) >= 0)
1574  ff_read_packet(ast2->sub_ctx, &ast2->sub_pkt);
1575 }
1576 
1577 static int avi_read_seek(AVFormatContext *s, int stream_index,
1578  int64_t timestamp, int flags)
1579 {
1580  AVIContext *avi = s->priv_data;
1581  AVStream *st;
1582  int i, index;
1583  int64_t pos, pos_min;
1584  AVIStream *ast;
1585 
1586  /* Does not matter which stream is requested dv in avi has the
1587  * stream information in the first video stream.
1588  */
1589  if (avi->dv_demux)
1590  stream_index = 0;
1591 
1592  if (!avi->index_loaded) {
1593  /* we only load the index on demand */
1594  avi_load_index(s);
1595  avi->index_loaded |= 1;
1596  }
1597  av_assert0(stream_index >= 0);
1598 
1599  st = s->streams[stream_index];
1600  ast = st->priv_data;
1601  index = av_index_search_timestamp(st,
1602  timestamp * FFMAX(ast->sample_size, 1),
1603  flags);
1604  if (index < 0) {
1605  if (st->nb_index_entries > 0)
1606  av_log(s, AV_LOG_DEBUG, "Failed to find timestamp %"PRId64 " in index %"PRId64 " .. %"PRId64 "\n",
1607  timestamp * FFMAX(ast->sample_size, 1),
1608  st->index_entries[0].timestamp,
1609  st->index_entries[st->nb_index_entries - 1].timestamp);
1610  return AVERROR_INVALIDDATA;
1611  }
1612 
1613  /* find the position */
1614  pos = st->index_entries[index].pos;
1615  timestamp = st->index_entries[index].timestamp / FFMAX(ast->sample_size, 1);
1616 
1617  av_dlog(s, "XX %"PRId64" %d %"PRId64"\n",
1618  timestamp, index, st->index_entries[index].timestamp);
1619 
1620  if (CONFIG_DV_DEMUXER && avi->dv_demux) {
1621  /* One and only one real stream for DV in AVI, and it has video */
1622  /* offsets. Calling with other stream indexes should have failed */
1623  /* the av_index_search_timestamp call above. */
1624 
1625  if (avio_seek(s->pb, pos, SEEK_SET) < 0)
1626  return -1;
1627 
1628  /* Feed the DV video stream version of the timestamp to the */
1629  /* DV demux so it can synthesize correct timestamps. */
1630  ff_dv_offset_reset(avi->dv_demux, timestamp);
1631 
1632  avi->stream_index = -1;
1633  return 0;
1634  }
1635 
1636  pos_min = pos;
1637  for (i = 0; i < s->nb_streams; i++) {
1638  AVStream *st2 = s->streams[i];
1639  AVIStream *ast2 = st2->priv_data;
1640 
1641  ast2->packet_size =
1642  ast2->remaining = 0;
1643 
1644  if (ast2->sub_ctx) {
1645  seek_subtitle(st, st2, timestamp);
1646  continue;
1647  }
1648 
1649  if (st2->nb_index_entries <= 0)
1650  continue;
1651 
1652 // av_assert1(st2->codec->block_align);
1653  av_assert0((int64_t)st2->time_base.num * ast2->rate ==
1654  (int64_t)st2->time_base.den * ast2->scale);
1655  index = av_index_search_timestamp(st2,
1656  av_rescale_q(timestamp,
1657  st->time_base,
1658  st2->time_base) *
1659  FFMAX(ast2->sample_size, 1),
1660  flags |
1661  AVSEEK_FLAG_BACKWARD |
1662  (st2->codec->codec_type != AVMEDIA_TYPE_VIDEO ? AVSEEK_FLAG_ANY : 0));
1663  if (index < 0)
1664  index = 0;
1665  ast2->seek_pos = st2->index_entries[index].pos;
1666  pos_min = FFMIN(pos_min,ast2->seek_pos);
1667  }
1668  for (i = 0; i < s->nb_streams; i++) {
1669  AVStream *st2 = s->streams[i];
1670  AVIStream *ast2 = st2->priv_data;
1671 
1672  if (ast2->sub_ctx || st2->nb_index_entries <= 0)
1673  continue;
1674 
1675  index = av_index_search_timestamp(
1676  st2,
1677  av_rescale_q(timestamp, st->time_base, st2->time_base) * FFMAX(ast2->sample_size, 1),
1678  flags | AVSEEK_FLAG_BACKWARD | (st2->codec->codec_type != AVMEDIA_TYPE_VIDEO ? AVSEEK_FLAG_ANY : 0));
1679  if (index < 0)
1680  index = 0;
1681  while (!avi->non_interleaved && index>0 && st2->index_entries[index-1].pos >= pos_min)
1682  index--;
1683  ast2->frame_offset = st2->index_entries[index].timestamp;
1684  }
1685 
1686  /* do the seek */
1687  if (avio_seek(s->pb, pos_min, SEEK_SET) < 0) {
1688  av_log(s, AV_LOG_ERROR, "Seek failed\n");
1689  return -1;
1690  }
1691  avi->stream_index = -1;
1692  avi->dts_max = INT_MIN;
1693  return 0;
1694 }
1695 
1696 static int avi_read_close(AVFormatContext *s)
1697 {
1698  int i;
1699  AVIContext *avi = s->priv_data;
1700 
1701  for (i = 0; i < s->nb_streams; i++) {
1702  AVStream *st = s->streams[i];
1703  AVIStream *ast = st->priv_data;
1704  if (ast) {
1705  if (ast->sub_ctx) {
1706  av_freep(&ast->sub_ctx->pb);
1707  avformat_close_input(&ast->sub_ctx);
1708  }
1709  av_free(ast->sub_buffer);
1710  av_free_packet(&ast->sub_pkt);
1711  }
1712  }
1713 
1714  av_free(avi->dv_demux);
1715 
1716  return 0;
1717 }
1718 
1719 static int avi_probe(AVProbeData *p)
1720 {
1721  int i;
1722 
1723  /* check file header */
1724  for (i = 0; avi_headers[i][0]; i++)
1725  if (!memcmp(p->buf, avi_headers[i], 4) &&
1726  !memcmp(p->buf + 8, avi_headers[i] + 4, 4))
1727  return AVPROBE_SCORE_MAX;
1728 
1729  return 0;
1730 }
1731 
1732 AVInputFormat ff_avi_demuxer = {
1733  .name = "avi",
1734  .long_name = NULL_IF_CONFIG_SMALL("AVI (Audio Video Interleaved)"),
1735  .priv_data_size = sizeof(AVIContext),
1736  .read_probe = avi_probe,
1737  .read_header = avi_read_header,
1738  .read_packet = avi_read_packet,
1739  .read_close = avi_read_close,
1740  .read_seek = avi_read_seek,
1741  .priv_class = &demuxer_class,
1742 };
Generated on Sun Mar 23 2014 23:50:10 for FFmpeg by   doxygen 1.8.2