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