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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 "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 AVERROR_INVALIDDATA;
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 AVERROR_INVALIDDATA;
172  st= s->streams[stream_id];
173  ast = st->priv_data;
174 
175  if(index_sub_type)
176  return AVERROR_INVALIDDATA;
177 
178  avio_rl32(pb);
179 
180  if(index_type && longs_pre_entry != 2)
181  return AVERROR_INVALIDDATA;
182  if(index_type>1)
183  return AVERROR_INVALIDDATA;
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 AVERROR_INVALIDDATA;
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 AVERROR_INVALIDDATA;
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 AVERROR_INVALIDDATA;
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 AVERROR_INVALIDDATA;
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 AVERROR(EINVAL);
283  value = av_malloc(size+1);
284  if (!value)
285  return AVERROR(ENOMEM);
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  ret = get_riff(s, pb);
371  if (ret < 0)
372  return ret;
373 
374  av_log(avi, AV_LOG_DEBUG, "use odml:%d\n", avi->use_odml);
375 
376  avi->fsize = avio_size(pb);
377  if(avi->fsize<=0 || avi->fsize < avi->riff_end)
378  avi->fsize= avi->riff_end == 8 ? INT64_MAX : avi->riff_end;
379 
380  /* first list tag */
381  stream_index = -1;
382  codec_type = -1;
383  frame_period = 0;
384  for(;;) {
385  if (url_feof(pb))
386  goto fail;
387  tag = avio_rl32(pb);
388  size = avio_rl32(pb);
389 
390  print_tag("tag", tag, size);
391 
392  switch(tag) {
393  case MKTAG('L', 'I', 'S', 'T'):
394  list_end = avio_tell(pb) + size;
395  /* Ignored, except at start of video packets. */
396  tag1 = avio_rl32(pb);
397 
398  print_tag("list", tag1, 0);
399 
400  if (tag1 == MKTAG('m', 'o', 'v', 'i')) {
401  avi->movi_list = avio_tell(pb) - 4;
402  if(size) avi->movi_end = avi->movi_list + size + (size & 1);
403  else avi->movi_end = avi->fsize;
404  av_dlog(NULL, "movi end=%"PRIx64"\n", avi->movi_end);
405  goto end_of_header;
406  }
407  else if (tag1 == MKTAG('I', 'N', 'F', 'O'))
408  ff_read_riff_info(s, size - 4);
409  else if (tag1 == MKTAG('n', 'c', 'd', 't'))
410  avi_read_nikon(s, list_end);
411 
412  break;
413  case MKTAG('I', 'D', 'I', 'T'): {
414  unsigned char date[64] = {0};
415  size += (size & 1);
416  size -= avio_read(pb, date, FFMIN(size, sizeof(date)-1));
417  avio_skip(pb, size);
419  break;
420  }
421  case MKTAG('d', 'm', 'l', 'h'):
422  avi->is_odml = 1;
423  avio_skip(pb, size + (size & 1));
424  break;
425  case MKTAG('a', 'm', 'v', 'h'):
426  amv_file_format=1;
427  case MKTAG('a', 'v', 'i', 'h'):
428  /* AVI header */
429  /* using frame_period is bad idea */
430  frame_period = avio_rl32(pb);
431  avio_rl32(pb); /* max. bytes per second */
432  avio_rl32(pb);
434 
435  avio_skip(pb, 2 * 4);
436  avio_rl32(pb);
437  avio_rl32(pb);
438  avih_width=avio_rl32(pb);
439  avih_height=avio_rl32(pb);
440 
441  avio_skip(pb, size - 10 * 4);
442  break;
443  case MKTAG('s', 't', 'r', 'h'):
444  /* stream header */
445 
446  tag1 = avio_rl32(pb);
447  handler = avio_rl32(pb); /* codec tag */
448 
449  if(tag1 == MKTAG('p', 'a', 'd', 's')){
450  avio_skip(pb, size - 8);
451  break;
452  }else{
453  stream_index++;
454  st = avformat_new_stream(s, NULL);
455  if (!st)
456  goto fail;
457 
458  st->id = stream_index;
459  ast = av_mallocz(sizeof(AVIStream));
460  if (!ast)
461  goto fail;
462  st->priv_data = ast;
463  }
464  if(amv_file_format)
465  tag1 = stream_index ? MKTAG('a','u','d','s') : MKTAG('v','i','d','s');
466 
467  print_tag("strh", tag1, -1);
468 
469  if(tag1 == MKTAG('i', 'a', 'v', 's') || tag1 == MKTAG('i', 'v', 'a', 's')){
470  int64_t dv_dur;
471 
472  /*
473  * After some consideration -- I don't think we
474  * have to support anything but DV in type1 AVIs.
475  */
476  if (s->nb_streams != 1)
477  goto fail;
478 
479  if (handler != MKTAG('d', 'v', 's', 'd') &&
480  handler != MKTAG('d', 'v', 'h', 'd') &&
481  handler != MKTAG('d', 'v', 's', 'l'))
482  goto fail;
483 
484  ast = s->streams[0]->priv_data;
485  av_freep(&s->streams[0]->codec->extradata);
486  av_freep(&s->streams[0]->codec);
487  if (s->streams[0]->info)
489  av_freep(&s->streams[0]->info);
490  av_freep(&s->streams[0]);
491  s->nb_streams = 0;
492  if (CONFIG_DV_DEMUXER) {
493  avi->dv_demux = avpriv_dv_init_demux(s);
494  if (!avi->dv_demux)
495  goto fail;
496  }
497  s->streams[0]->priv_data = ast;
498  avio_skip(pb, 3 * 4);
499  ast->scale = avio_rl32(pb);
500  ast->rate = avio_rl32(pb);
501  avio_skip(pb, 4); /* start time */
502 
503  dv_dur = avio_rl32(pb);
504  if (ast->scale > 0 && ast->rate > 0 && dv_dur > 0) {
505  dv_dur *= AV_TIME_BASE;
506  s->duration = av_rescale(dv_dur, ast->scale, ast->rate);
507  }
508  /*
509  * else, leave duration alone; timing estimation in utils.c
510  * will make a guess based on bitrate.
511  */
512 
513  stream_index = s->nb_streams - 1;
514  avio_skip(pb, size - 9*4);
515  break;
516  }
517 
518  av_assert0(stream_index < s->nb_streams);
519  st->codec->stream_codec_tag= handler;
520 
521  avio_rl32(pb); /* flags */
522  avio_rl16(pb); /* priority */
523  avio_rl16(pb); /* language */
524  avio_rl32(pb); /* initial frame */
525  ast->scale = avio_rl32(pb);
526  ast->rate = avio_rl32(pb);
527  if(!(ast->scale && ast->rate)){
528  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);
529  if(frame_period){
530  ast->rate = 1000000;
531  ast->scale = frame_period;
532  }else{
533  ast->rate = 25;
534  ast->scale = 1;
535  }
536  }
537  avpriv_set_pts_info(st, 64, ast->scale, ast->rate);
538 
539  ast->cum_len=avio_rl32(pb); /* start */
540  st->nb_frames = avio_rl32(pb);
541 
542  st->start_time = 0;
543  avio_rl32(pb); /* buffer size */
544  avio_rl32(pb); /* quality */
545  if (ast->cum_len*ast->scale/ast->rate > 3600) {
546  av_log(s, AV_LOG_ERROR, "crazy start time, iam scared, giving up\n");
547  return AVERROR_INVALIDDATA;
548  }
549  ast->sample_size = avio_rl32(pb); /* sample ssize */
550  ast->cum_len *= FFMAX(1, ast->sample_size);
551  av_dlog(s, "%"PRIu32" %"PRIu32" %d\n",
552  ast->rate, ast->scale, ast->sample_size);
553 
554  switch(tag1) {
555  case MKTAG('v', 'i', 'd', 's'):
556  codec_type = AVMEDIA_TYPE_VIDEO;
557 
558  ast->sample_size = 0;
559  break;
560  case MKTAG('a', 'u', 'd', 's'):
561  codec_type = AVMEDIA_TYPE_AUDIO;
562  break;
563  case MKTAG('t', 'x', 't', 's'):
564  codec_type = AVMEDIA_TYPE_SUBTITLE;
565  break;
566  case MKTAG('d', 'a', 't', 's'):
567  codec_type = AVMEDIA_TYPE_DATA;
568  break;
569  default:
570  av_log(s, AV_LOG_INFO, "unknown stream type %X\n", tag1);
571  }
572  if(ast->sample_size == 0)
573  st->duration = st->nb_frames;
574  ast->frame_offset= ast->cum_len;
575  avio_skip(pb, size - 12 * 4);
576  break;
577  case MKTAG('s', 't', 'r', 'f'):
578  /* stream header */
579  if (!size)
580  break;
581  if (stream_index >= (unsigned)s->nb_streams || avi->dv_demux) {
582  avio_skip(pb, size);
583  } else {
584  uint64_t cur_pos = avio_tell(pb);
585  unsigned esize;
586  if (cur_pos < list_end)
587  size = FFMIN(size, list_end - cur_pos);
588  st = s->streams[stream_index];
589  switch(codec_type) {
590  case AVMEDIA_TYPE_VIDEO:
591  if(amv_file_format){
592  st->codec->width=avih_width;
593  st->codec->height=avih_height;
596  avio_skip(pb, size);
597  break;
598  }
599  tag1 = ff_get_bmp_header(pb, st, &esize);
600 
601  if (tag1 == MKTAG('D', 'X', 'S', 'B') || tag1 == MKTAG('D','X','S','A')) {
603  st->codec->codec_tag = tag1;
605  break;
606  }
607 
608  if(size > 10*4 && size<(1<<30) && size < avi->fsize){
609  if(esize == size-1 && (esize&1)) st->codec->extradata_size= esize - 10*4;
610  else st->codec->extradata_size= size - 10*4;
612  if (!st->codec->extradata) {
613  st->codec->extradata_size= 0;
614  return AVERROR(ENOMEM);
615  }
616  avio_read(pb, st->codec->extradata, st->codec->extradata_size);
617  }
618 
619  if(st->codec->extradata_size & 1) //FIXME check if the encoder really did this correctly
620  avio_r8(pb);
621 
622  /* Extract palette from extradata if bpp <= 8. */
623  /* This code assumes that extradata contains only palette. */
624  /* This is true for all paletted codecs implemented in FFmpeg. */
625  if (st->codec->extradata_size && (st->codec->bits_per_coded_sample <= 8)) {
626  int pal_size = (1 << st->codec->bits_per_coded_sample) << 2;
627  const uint8_t *pal_src;
628 
629  pal_size = FFMIN(pal_size, st->codec->extradata_size);
630  pal_src = st->codec->extradata + st->codec->extradata_size - pal_size;
631  for (i = 0; i < pal_size/4; i++)
632  ast->pal[i] = 0xFFU<<24 | AV_RL32(pal_src+4*i);
633  ast->has_pal = 1;
634  }
635 
636  print_tag("video", tag1, 0);
637 
639  st->codec->codec_tag = tag1;
641  st->need_parsing = AVSTREAM_PARSE_HEADERS; // This is needed to get the pict type which is necessary for generating correct pts.
642 
643  if(st->codec->codec_tag==0 && st->codec->height > 0 && st->codec->extradata_size < 1U<<30){
644  st->codec->extradata_size+= 9;
646  if(st->codec->extradata)
647  memcpy(st->codec->extradata + st->codec->extradata_size - 9, "BottomUp", 9);
648  }
649  st->codec->height= FFABS(st->codec->height);
650 
651 // avio_skip(pb, size - 5 * 4);
652  break;
653  case AVMEDIA_TYPE_AUDIO:
654  ret = ff_get_wav_header(pb, st->codec, size);
655  if (ret < 0)
656  return ret;
658  if(ast->sample_size && st->codec->block_align && ast->sample_size != st->codec->block_align){
659  av_log(s, AV_LOG_WARNING, "sample size (%d) != block align (%d)\n", ast->sample_size, st->codec->block_align);
660  ast->sample_size= st->codec->block_align;
661  }
662  if (size&1) /* 2-aligned (fix for Stargate SG-1 - 3x18 - Shades of Grey.avi) */
663  avio_skip(pb, 1);
664  /* Force parsing as several audio frames can be in
665  * one packet and timestamps refer to packet start. */
667  /* ADTS header is in extradata, AAC without header must be
668  * stored as exact frames. Parser not needed and it will
669  * fail. */
670  if (st->codec->codec_id == AV_CODEC_ID_AAC && st->codec->extradata_size)
672  /* AVI files with Xan DPCM audio (wrongly) declare PCM
673  * audio in the header but have Axan as stream_code_tag. */
674  if (st->codec->stream_codec_tag == AV_RL32("Axan")){
676  st->codec->codec_tag = 0;
677  ast->dshow_block_align = 0;
678  }
679  if (amv_file_format){
681  ast->dshow_block_align = 0;
682  }
683  if(st->codec->codec_id == AV_CODEC_ID_AAC && ast->dshow_block_align <= 4 && ast->dshow_block_align) {
684  av_log(s, AV_LOG_DEBUG, "overriding invalid dshow_block_align of %d\n", ast->dshow_block_align);
685  ast->dshow_block_align = 0;
686  }
687  if(st->codec->codec_id == AV_CODEC_ID_AAC && ast->dshow_block_align == 1024 && ast->sample_size == 1024 ||
688  st->codec->codec_id == AV_CODEC_ID_AAC && ast->dshow_block_align == 4096 && ast->sample_size == 4096 ||
689  st->codec->codec_id == AV_CODEC_ID_MP3 && ast->dshow_block_align == 1152 && ast->sample_size == 1152) {
690  av_log(s, AV_LOG_DEBUG, "overriding sample_size\n");
691  ast->sample_size = 0;
692  }
693  break;
696  st->request_probe= 1;
697  avio_skip(pb, size);
698  break;
699  default:
702  st->codec->codec_tag= 0;
703  avio_skip(pb, size);
704  break;
705  }
706  }
707  break;
708  case MKTAG('s', 't', 'r', 'd'):
709  if (stream_index >= (unsigned)s->nb_streams
710  || s->streams[stream_index]->codec->extradata_size
711  || s->streams[stream_index]->codec->codec_tag == MKTAG('H','2','6','4')) {
712  avio_skip(pb, size);
713  } else {
714  uint64_t cur_pos = avio_tell(pb);
715  if (cur_pos < list_end)
716  size = FFMIN(size, list_end - cur_pos);
717  st = s->streams[stream_index];
718 
719  if(size<(1<<30)){
720  st->codec->extradata_size= size;
722  if (!st->codec->extradata) {
723  st->codec->extradata_size= 0;
724  return AVERROR(ENOMEM);
725  }
726  avio_read(pb, st->codec->extradata, st->codec->extradata_size);
727  }
728 
729  if(st->codec->extradata_size & 1) //FIXME check if the encoder really did this correctly
730  avio_r8(pb);
731  }
732  break;
733  case MKTAG('i', 'n', 'd', 'x'):
734  i= avio_tell(pb);
735  if(pb->seekable && !(s->flags & AVFMT_FLAG_IGNIDX) && avi->use_odml &&
737  goto fail;
738  avio_seek(pb, i+size, SEEK_SET);
739  break;
740  case MKTAG('v', 'p', 'r', 'p'):
741  if(stream_index < (unsigned)s->nb_streams && size > 9*4){
742  AVRational active, active_aspect;
743 
744  st = s->streams[stream_index];
745  avio_rl32(pb);
746  avio_rl32(pb);
747  avio_rl32(pb);
748  avio_rl32(pb);
749  avio_rl32(pb);
750 
751  active_aspect.den= avio_rl16(pb);
752  active_aspect.num= avio_rl16(pb);
753  active.num = avio_rl32(pb);
754  active.den = avio_rl32(pb);
755  avio_rl32(pb); //nbFieldsPerFrame
756 
757  if(active_aspect.num && active_aspect.den && active.num && active.den){
758  st->sample_aspect_ratio= av_div_q(active_aspect, active);
759  av_dlog(s, "vprp %d/%d %d/%d\n",
760  active_aspect.num, active_aspect.den,
761  active.num, active.den);
762  }
763  size -= 9*4;
764  }
765  avio_skip(pb, size);
766  break;
767  case MKTAG('s', 't', 'r', 'n'):
768  if(s->nb_streams){
769  ret = avi_read_tag(s, s->streams[s->nb_streams-1], tag, size);
770  if (ret < 0)
771  return ret;
772  break;
773  }
774  default:
775  if(size > 1000000){
776  av_log(s, AV_LOG_ERROR, "Something went wrong during header parsing, "
777  "I will ignore it and try to continue anyway.\n");
779  goto fail;
780  avi->movi_list = avio_tell(pb) - 4;
781  avi->movi_end = avi->fsize;
782  goto end_of_header;
783  }
784  /* skip tag */
785  size += (size & 1);
786  avio_skip(pb, size);
787  break;
788  }
789  }
790  end_of_header:
791  /* check stream number */
792  if (stream_index != s->nb_streams - 1) {
793  fail:
794  return AVERROR_INVALIDDATA;
795  }
796 
797  if(!avi->index_loaded && pb->seekable)
798  avi_load_index(s);
799  avi->index_loaded |= 1;
801  for(i=0; i<s->nb_streams; i++){
802  AVStream *st = s->streams[i];
803  if(st->nb_index_entries)
804  break;
805  }
806  // DV-in-AVI cannot be non-interleaved, if set this must be
807  // a mis-detection.
808  if(avi->dv_demux)
809  avi->non_interleaved=0;
810  if(i==s->nb_streams && avi->non_interleaved) {
811  av_log(s, AV_LOG_WARNING, "non-interleaved AVI without index, switching to interleaved\n");
812  avi->non_interleaved=0;
813  }
814 
815  if(avi->non_interleaved) {
816  av_log(s, AV_LOG_INFO, "non-interleaved AVI\n");
817  clean_index(s);
818  }
819 
820  ff_metadata_conv_ctx(s, NULL, avi_metadata_conv);
822 
823  return 0;
824 }
825 
826 static int read_gab2_sub(AVStream *st, AVPacket *pkt) {
827  if (pkt->data && !strcmp(pkt->data, "GAB2") && AV_RL16(pkt->data+5) == 2) {
828  uint8_t desc[256];
829  int score = AVPROBE_SCORE_MAX / 2, ret;
830  AVIStream *ast = st->priv_data;
831  AVInputFormat *sub_demuxer;
832  AVRational time_base;
833  AVIOContext *pb = avio_alloc_context( pkt->data + 7,
834  pkt->size - 7,
835  0, NULL, NULL, NULL, NULL);
836  AVProbeData pd;
837  unsigned int desc_len = avio_rl32(pb);
838 
839  if (desc_len > pb->buf_end - pb->buf_ptr)
840  goto error;
841 
842  ret = avio_get_str16le(pb, desc_len, desc, sizeof(desc));
843  avio_skip(pb, desc_len - ret);
844  if (*desc)
845  av_dict_set(&st->metadata, "title", desc, 0);
846 
847  avio_rl16(pb); /* flags? */
848  avio_rl32(pb); /* data size */
849 
850  pd = (AVProbeData) { .buf = pb->buf_ptr, .buf_size = pb->buf_end - pb->buf_ptr };
851  if (!(sub_demuxer = av_probe_input_format2(&pd, 1, &score)))
852  goto error;
853 
854  if (!(ast->sub_ctx = avformat_alloc_context()))
855  goto error;
856 
857  ast->sub_ctx->pb = pb;
858  if (!avformat_open_input(&ast->sub_ctx, "", sub_demuxer, NULL)) {
859  ff_read_packet(ast->sub_ctx, &ast->sub_pkt);
860  *st->codec = *ast->sub_ctx->streams[0]->codec;
861  ast->sub_ctx->streams[0]->codec->extradata = NULL;
862  time_base = ast->sub_ctx->streams[0]->time_base;
863  avpriv_set_pts_info(st, 64, time_base.num, time_base.den);
864  }
865  ast->sub_buffer = pkt->data;
866  memset(pkt, 0, sizeof(*pkt));
867  return 1;
868 error:
869  av_freep(&pb);
870  }
871  return 0;
872 }
873 
875  AVPacket *pkt)
876 {
877  AVIStream *ast, *next_ast = next_st->priv_data;
878  int64_t ts, next_ts, ts_min = INT64_MAX;
879  AVStream *st, *sub_st = NULL;
880  int i;
881 
882  next_ts = av_rescale_q(next_ast->frame_offset, next_st->time_base,
884 
885  for (i=0; i<s->nb_streams; i++) {
886  st = s->streams[i];
887  ast = st->priv_data;
888  if (st->discard < AVDISCARD_ALL && ast && ast->sub_pkt.data) {
890  if (ts <= next_ts && ts < ts_min) {
891  ts_min = ts;
892  sub_st = st;
893  }
894  }
895  }
896 
897  if (sub_st) {
898  ast = sub_st->priv_data;
899  *pkt = ast->sub_pkt;
900  pkt->stream_index = sub_st->index;
901  if (ff_read_packet(ast->sub_ctx, &ast->sub_pkt) < 0)
902  ast->sub_pkt.data = NULL;
903  }
904  return sub_st;
905 }
906 
907 static int get_stream_idx(int *d){
908  if( d[0] >= '0' && d[0] <= '9'
909  && d[1] >= '0' && d[1] <= '9'){
910  return (d[0] - '0') * 10 + (d[1] - '0');
911  }else{
912  return 100; //invalid stream ID
913  }
914 }
915 
916 /**
917  *
918  * @param exit_early set to 1 to just gather packet position without making the changes needed to actually read & return the packet
919  */
920 static int avi_sync(AVFormatContext *s, int exit_early)
921 {
922  AVIContext *avi = s->priv_data;
923  AVIOContext *pb = s->pb;
924  int n;
925  unsigned int d[8];
926  unsigned int size;
927  int64_t i, sync;
928 
929 start_sync:
930  memset(d, -1, sizeof(d));
931  for(i=sync=avio_tell(pb); !url_feof(pb); i++) {
932  int j;
933 
934  for(j=0; j<7; j++)
935  d[j]= d[j+1];
936  d[7]= avio_r8(pb);
937 
938  size= d[4] + (d[5]<<8) + (d[6]<<16) + (d[7]<<24);
939 
940  n= get_stream_idx(d+2);
941  av_dlog(s, "%X %X %X %X %X %X %X %X %"PRId64" %u %d\n",
942  d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7], i, size, n);
943  if(i + (uint64_t)size > avi->fsize || d[0] > 127)
944  continue;
945 
946  //parse ix##
947  if( (d[0] == 'i' && d[1] == 'x' && n < s->nb_streams)
948  //parse JUNK
949  ||(d[0] == 'J' && d[1] == 'U' && d[2] == 'N' && d[3] == 'K')
950  ||(d[0] == 'i' && d[1] == 'd' && d[2] == 'x' && d[3] == '1')){
951  avio_skip(pb, size);
952  goto start_sync;
953  }
954 
955  //parse stray LIST
956  if(d[0] == 'L' && d[1] == 'I' && d[2] == 'S' && d[3] == 'T'){
957  avio_skip(pb, 4);
958  goto start_sync;
959  }
960 
961  n= get_stream_idx(d);
962 
963  if(!((i-avi->last_pkt_pos)&1) && get_stream_idx(d+1) < s->nb_streams)
964  continue;
965 
966  //detect ##ix chunk and skip
967  if(d[2] == 'i' && d[3] == 'x' && n < s->nb_streams){
968  avio_skip(pb, size);
969  goto start_sync;
970  }
971 
972  //parse ##dc/##wb
973  if(n < s->nb_streams){
974  AVStream *st;
975  AVIStream *ast;
976  st = s->streams[n];
977  ast = st->priv_data;
978 
979  if (!ast) {
980  av_log(s, AV_LOG_WARNING, "Skiping foreign stream %d packet\n", n);
981  continue;
982  }
983 
984  if(s->nb_streams>=2){
985  AVStream *st1 = s->streams[1];
986  AVIStream *ast1= st1->priv_data;
987  //workaround for broken small-file-bug402.avi
988  if( d[2] == 'w' && d[3] == 'b'
989  && n==0
990  && st ->codec->codec_type == AVMEDIA_TYPE_VIDEO
992  && ast->prefix == 'd'*256+'c'
993  && (d[2]*256+d[3] == ast1->prefix || !ast1->prefix_count)
994  ){
995  n=1;
996  st = st1;
997  ast = ast1;
998  av_log(s, AV_LOG_WARNING, "Invalid stream + prefix combination, assuming audio.\n");
999  }
1000  }
1001 
1002 
1003  if( (st->discard >= AVDISCARD_DEFAULT && size==0)
1004  /*|| (st->discard >= AVDISCARD_NONKEY && !(pkt->flags & AV_PKT_FLAG_KEY))*/ //FIXME needs a little reordering
1005  || st->discard >= AVDISCARD_ALL){
1006  if (!exit_early) {
1007  ast->frame_offset += get_duration(ast, size);
1008  avio_skip(pb, size);
1009  goto start_sync;
1010  }
1011  }
1012 
1013  if (d[2] == 'p' && d[3] == 'c' && size<=4*256+4) {
1014  int k = avio_r8(pb);
1015  int last = (k + avio_r8(pb) - 1) & 0xFF;
1016 
1017  avio_rl16(pb); //flags
1018 
1019  for (; k <= last; k++)
1020  ast->pal[k] = 0xFFU<<24 | avio_rb32(pb)>>8;// b + (g << 8) + (r << 16);
1021  ast->has_pal= 1;
1022  goto start_sync;
1023  } else if( ((ast->prefix_count<5 || sync+9 > i) && d[2]<128 && d[3]<128) ||
1024  d[2]*256+d[3] == ast->prefix /*||
1025  (d[2] == 'd' && d[3] == 'c') ||
1026  (d[2] == 'w' && d[3] == 'b')*/) {
1027 
1028  if (exit_early)
1029  return 0;
1030  if(d[2]*256+d[3] == ast->prefix)
1031  ast->prefix_count++;
1032  else{
1033  ast->prefix= d[2]*256+d[3];
1034  ast->prefix_count= 0;
1035  }
1036 
1037  avi->stream_index= n;
1038  ast->packet_size= size + 8;
1039  ast->remaining= size;
1040 
1041  if(size || !ast->sample_size){
1042  uint64_t pos= avio_tell(pb) - 8;
1043  if(!st->index_entries || !st->nb_index_entries || st->index_entries[st->nb_index_entries - 1].pos < pos){
1044  av_add_index_entry(st, pos, ast->frame_offset, size, 0, AVINDEX_KEYFRAME);
1045  }
1046  }
1047  return 0;
1048  }
1049  }
1050  }
1051 
1052  if(pb->error)
1053  return pb->error;
1054  return AVERROR_EOF;
1055 }
1056 
1058 {
1059  AVIContext *avi = s->priv_data;
1060  AVIOContext *pb = s->pb;
1061  int err;
1062  void* dstr;
1063 
1064  if (CONFIG_DV_DEMUXER && avi->dv_demux) {
1065  int size = avpriv_dv_get_packet(avi->dv_demux, pkt);
1066  if (size >= 0)
1067  return size;
1068  }
1069 
1070  if(avi->non_interleaved){
1071  int best_stream_index = 0;
1072  AVStream *best_st= NULL;
1073  AVIStream *best_ast;
1074  int64_t best_ts= INT64_MAX;
1075  int i;
1076 
1077  for(i=0; i<s->nb_streams; i++){
1078  AVStream *st = s->streams[i];
1079  AVIStream *ast = st->priv_data;
1080  int64_t ts= ast->frame_offset;
1081  int64_t last_ts;
1082 
1083  if(!st->nb_index_entries)
1084  continue;
1085 
1086  last_ts = st->index_entries[st->nb_index_entries - 1].timestamp;
1087  if(!ast->remaining && ts > last_ts)
1088  continue;
1089 
1090  ts = av_rescale_q(ts, st->time_base, (AVRational){FFMAX(1, ast->sample_size), AV_TIME_BASE});
1091 
1092  av_dlog(s, "%"PRId64" %d/%d %"PRId64"\n", ts,
1093  st->time_base.num, st->time_base.den, ast->frame_offset);
1094  if(ts < best_ts){
1095  best_ts= ts;
1096  best_st= st;
1097  best_stream_index= i;
1098  }
1099  }
1100  if(!best_st)
1101  return AVERROR_EOF;
1102 
1103  best_ast = best_st->priv_data;
1104  best_ts = best_ast->frame_offset;
1105  if(best_ast->remaining)
1107  else{
1108  i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY);
1109  if(i>=0)
1110  best_ast->frame_offset= best_st->index_entries[i].timestamp;
1111  }
1112 
1113  if(i>=0){
1114  int64_t pos= best_st->index_entries[i].pos;
1115  pos += best_ast->packet_size - best_ast->remaining;
1116  if(avio_seek(s->pb, pos + 8, SEEK_SET) < 0)
1117  return AVERROR_EOF;
1118 
1119  av_assert0(best_ast->remaining <= best_ast->packet_size);
1120 
1121  avi->stream_index= best_stream_index;
1122  if(!best_ast->remaining)
1123  best_ast->packet_size=
1124  best_ast->remaining= best_st->index_entries[i].size;
1125  }
1126  else
1127  return AVERROR_EOF;
1128  }
1129 
1130 resync:
1131  if(avi->stream_index >= 0){
1132  AVStream *st= s->streams[ avi->stream_index ];
1133  AVIStream *ast= st->priv_data;
1134  int size, err;
1135 
1136  if(get_subtitle_pkt(s, st, pkt))
1137  return 0;
1138 
1139  if(ast->sample_size <= 1) // minorityreport.AVI block_align=1024 sample_size=1 IMA-ADPCM
1140  size= INT_MAX;
1141  else if(ast->sample_size < 32)
1142  // arbitrary multiplier to avoid tiny packets for raw PCM data
1143  size= 1024*ast->sample_size;
1144  else
1145  size= ast->sample_size;
1146 
1147  if(size > ast->remaining)
1148  size= ast->remaining;
1149  avi->last_pkt_pos= avio_tell(pb);
1150  err= av_get_packet(pb, pkt, size);
1151  if(err<0)
1152  return err;
1153  size = err;
1154 
1155  if(ast->has_pal && pkt->size<(unsigned)INT_MAX/2){
1156  uint8_t *pal;
1158  if(!pal){
1159  av_log(s, AV_LOG_ERROR, "Failed to allocate data for palette\n");
1160  }else{
1161  memcpy(pal, ast->pal, AVPALETTE_SIZE);
1162  ast->has_pal = 0;
1163  }
1164  }
1165 
1166  if (CONFIG_DV_DEMUXER && avi->dv_demux) {
1167  dstr = pkt->destruct;
1168  size = avpriv_dv_produce_packet(avi->dv_demux, pkt,
1169  pkt->data, pkt->size, pkt->pos);
1170  pkt->destruct = dstr;
1172  if (size < 0)
1174  } else if (st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE
1175  && !st->codec->codec_tag && read_gab2_sub(st, pkt)) {
1176  ast->frame_offset++;
1177  avi->stream_index = -1;
1178  ast->remaining = 0;
1179  goto resync;
1180  } else {
1181  /* XXX: How to handle B-frames in AVI? */
1182  pkt->dts = ast->frame_offset;
1183 // pkt->dts += ast->start;
1184  if(ast->sample_size)
1185  pkt->dts /= ast->sample_size;
1186  av_dlog(s, "dts:%"PRId64" offset:%"PRId64" %d/%d smpl_siz:%d base:%d st:%d size:%d\n",
1187  pkt->dts, ast->frame_offset, ast->scale, ast->rate,
1188  ast->sample_size, AV_TIME_BASE, avi->stream_index, size);
1189  pkt->stream_index = avi->stream_index;
1190 
1191  if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
1192  AVIndexEntry *e;
1193  int index;
1195 
1196  index= av_index_search_timestamp(st, ast->frame_offset, 0);
1197  e= &st->index_entries[index];
1198 
1199  if(index >= 0 && e->timestamp == ast->frame_offset){
1200  if (index == st->nb_index_entries-1){
1201  int key=1;
1202  int i;
1203  uint32_t state=-1;
1204  for(i=0; i<FFMIN(size,256); i++){
1205  if(st->codec->codec_id == AV_CODEC_ID_MPEG4){
1206  if(state == 0x1B6){
1207  key= !(pkt->data[i]&0xC0);
1208  break;
1209  }
1210  }else
1211  break;
1212  state= (state<<8) + pkt->data[i];
1213  }
1214  if(!key)
1215  e->flags &= ~AVINDEX_KEYFRAME;
1216  }
1217  if (e->flags & AVINDEX_KEYFRAME)
1219  }
1220  } else {
1222  }
1223  ast->frame_offset += get_duration(ast, pkt->size);
1224  }
1225  ast->remaining -= err;
1226  if(!ast->remaining){
1227  avi->stream_index= -1;
1228  ast->packet_size= 0;
1229  }
1230 
1231  if(!avi->non_interleaved && pkt->pos >= 0 && ast->seek_pos > pkt->pos){
1233  goto resync;
1234  }
1235  ast->seek_pos= 0;
1236 
1237  if(!avi->non_interleaved && st->nb_index_entries>1 && avi->index_loaded>1){
1238  int64_t dts= av_rescale_q(pkt->dts, st->time_base, AV_TIME_BASE_Q);
1239 
1240  if(avi->dts_max - dts > 2*AV_TIME_BASE){
1241  avi->non_interleaved= 1;
1242  av_log(s, AV_LOG_INFO, "Switching to NI mode, due to poor interleaving\n");
1243  }else if(avi->dts_max < dts)
1244  avi->dts_max = dts;
1245  }
1246 
1247  return 0;
1248  }
1249 
1250  if ((err = avi_sync(s, 0)) < 0)
1251  return err;
1252  goto resync;
1253 }
1254 
1255 /* XXX: We make the implicit supposition that the positions are sorted
1256  for each stream. */
1257 static int avi_read_idx1(AVFormatContext *s, int size)
1258 {
1259  AVIContext *avi = s->priv_data;
1260  AVIOContext *pb = s->pb;
1261  int nb_index_entries, i;
1262  AVStream *st;
1263  AVIStream *ast;
1264  unsigned int index, tag, flags, pos, len, first_packet = 1;
1265  unsigned last_pos= -1;
1266  unsigned last_idx= -1;
1267  int64_t idx1_pos, first_packet_pos = 0, data_offset = 0;
1268  int anykey = 0;
1269 
1270  nb_index_entries = size / 16;
1271  if (nb_index_entries <= 0)
1272  return AVERROR_INVALIDDATA;
1273 
1274  idx1_pos = avio_tell(pb);
1275  avio_seek(pb, avi->movi_list+4, SEEK_SET);
1276  if (avi_sync(s, 1) == 0) {
1277  first_packet_pos = avio_tell(pb) - 8;
1278  }
1279  avi->stream_index = -1;
1280  avio_seek(pb, idx1_pos, SEEK_SET);
1281 
1282  if (s->nb_streams == 1 && s->streams[0]->codec->codec_tag == AV_RL32("MMES")){
1283  first_packet_pos = 0;
1284  data_offset = avi->movi_list;
1285  }
1286 
1287  /* Read the entries and sort them in each stream component. */
1288  for(i = 0; i < nb_index_entries; i++) {
1289  if(url_feof(pb))
1290  return -1;
1291 
1292  tag = avio_rl32(pb);
1293  flags = avio_rl32(pb);
1294  pos = avio_rl32(pb);
1295  len = avio_rl32(pb);
1296  av_dlog(s, "%d: tag=0x%x flags=0x%x pos=0x%x len=%d/",
1297  i, tag, flags, pos, len);
1298 
1299  index = ((tag & 0xff) - '0') * 10;
1300  index += ((tag >> 8) & 0xff) - '0';
1301  if (index >= s->nb_streams)
1302  continue;
1303  st = s->streams[index];
1304  ast = st->priv_data;
1305 
1306  if(first_packet && first_packet_pos && len) {
1307  data_offset = first_packet_pos - pos;
1308  first_packet = 0;
1309  }
1310  pos += data_offset;
1311 
1312  av_dlog(s, "%d cum_len=%"PRId64"\n", len, ast->cum_len);
1313 
1314  // even if we have only a single stream, we should
1315  // switch to non-interleaved to get correct timestamps
1316  if(last_pos == pos)
1317  avi->non_interleaved= 1;
1318  if(last_idx != pos && len) {
1319  av_add_index_entry(st, pos, ast->cum_len, len, 0, (flags&AVIIF_INDEX) ? AVINDEX_KEYFRAME : 0);
1320  last_idx= pos;
1321  }
1322  ast->cum_len += get_duration(ast, len);
1323  last_pos= pos;
1324  anykey |= flags&AVIIF_INDEX;
1325  }
1326  if (!anykey) {
1327  for (index = 0; index < s->nb_streams; index++) {
1328  st = s->streams[index];
1329  if (st->nb_index_entries)
1331  }
1332  }
1333  return 0;
1334 }
1335 
1337  int i;
1338  int64_t last_start=0;
1339  int64_t first_end= INT64_MAX;
1340  int64_t oldpos= avio_tell(s->pb);
1341  int *idx;
1342  int64_t min_pos, pos;
1343 
1344  for(i=0; i<s->nb_streams; i++){
1345  AVStream *st = s->streams[i];
1346  int n= st->nb_index_entries;
1347  unsigned int size;
1348 
1349  if(n <= 0)
1350  continue;
1351 
1352  if(n >= 2){
1353  int64_t pos= st->index_entries[0].pos;
1354  avio_seek(s->pb, pos + 4, SEEK_SET);
1355  size= avio_rl32(s->pb);
1356  if(pos + size > st->index_entries[1].pos)
1357  last_start= INT64_MAX;
1358  }
1359 
1360  if(st->index_entries[0].pos > last_start)
1361  last_start= st->index_entries[0].pos;
1362  if(st->index_entries[n-1].pos < first_end)
1363  first_end= st->index_entries[n-1].pos;
1364  }
1365  avio_seek(s->pb, oldpos, SEEK_SET);
1366  if (last_start > first_end)
1367  return 1;
1368  idx= av_mallocz(sizeof(*idx) * s->nb_streams);
1369  for (min_pos=pos=0; min_pos!=INT64_MAX; pos= min_pos+1LU) {
1370  int64_t max_dts = INT64_MIN/2, min_dts= INT64_MAX/2;
1371  min_pos = INT64_MAX;
1372 
1373  for (i=0; i<s->nb_streams; i++) {
1374  AVStream *st = s->streams[i];
1375  int n= st->nb_index_entries;
1376  while (idx[i]<n && st->index_entries[idx[i]].pos < pos)
1377  idx[i]++;
1378  if (idx[i] < n) {
1379  min_dts = FFMIN(min_dts, av_rescale_q(st->index_entries[idx[i]].timestamp, st->time_base, AV_TIME_BASE_Q));
1380  min_pos = FFMIN(min_pos, st->index_entries[idx[i]].pos);
1381  }
1382  if (idx[i])
1383  max_dts = FFMAX(max_dts, av_rescale_q(st->index_entries[idx[i]-1].timestamp, st->time_base, AV_TIME_BASE_Q));
1384  }
1385  if(max_dts - min_dts > 2*AV_TIME_BASE) {
1386  av_free(idx);
1387  return 1;
1388  }
1389  }
1390  av_free(idx);
1391  return 0;
1392 }
1393 
1395 {
1396  AVIContext *avi = s->priv_data;
1397  AVIOContext *pb = s->pb;
1398  uint32_t tag, size;
1399  int64_t pos= avio_tell(pb);
1400  int64_t next;
1401  int ret = -1;
1402 
1403  if (avio_seek(pb, avi->movi_end, SEEK_SET) < 0)
1404  goto the_end; // maybe truncated file
1405  av_dlog(s, "movi_end=0x%"PRIx64"\n", avi->movi_end);
1406  for(;;) {
1407  tag = avio_rl32(pb);
1408  size = avio_rl32(pb);
1409  if (url_feof(pb))
1410  break;
1411  next = avio_tell(pb) + size + (size & 1);
1412 
1413  av_dlog(s, "tag=%c%c%c%c size=0x%x\n",
1414  tag & 0xff,
1415  (tag >> 8) & 0xff,
1416  (tag >> 16) & 0xff,
1417  (tag >> 24) & 0xff,
1418  size);
1419 
1420  if (tag == MKTAG('i', 'd', 'x', '1') &&
1421  avi_read_idx1(s, size) >= 0) {
1422  avi->index_loaded=2;
1423  ret = 0;
1424  }else if(tag == MKTAG('L', 'I', 'S', 'T')) {
1425  uint32_t tag1 = avio_rl32(pb);
1426 
1427  if (tag1 == MKTAG('I', 'N', 'F', 'O'))
1428  ff_read_riff_info(s, size - 4);
1429  }else if(!ret)
1430  break;
1431 
1432  if (avio_seek(pb, next, SEEK_SET) < 0)
1433  break; // something is wrong here
1434  }
1435  the_end:
1436  avio_seek(pb, pos, SEEK_SET);
1437  return ret;
1438 }
1439 
1440 static void seek_subtitle(AVStream *st, AVStream *st2, int64_t timestamp)
1441 {
1442  AVIStream *ast2 = st2->priv_data;
1443  int64_t ts2 = av_rescale_q(timestamp, st->time_base, st2->time_base);
1444  av_free_packet(&ast2->sub_pkt);
1445  if (avformat_seek_file(ast2->sub_ctx, 0, INT64_MIN, ts2, ts2, 0) >= 0 ||
1446  avformat_seek_file(ast2->sub_ctx, 0, ts2, ts2, INT64_MAX, 0) >= 0)
1447  ff_read_packet(ast2->sub_ctx, &ast2->sub_pkt);
1448 }
1449 
1450 static int avi_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
1451 {
1452  AVIContext *avi = s->priv_data;
1453  AVStream *st;
1454  int i, index;
1455  int64_t pos, pos_min;
1456  AVIStream *ast;
1457 
1458  if (!avi->index_loaded) {
1459  /* we only load the index on demand */
1460  avi_load_index(s);
1461  avi->index_loaded |= 1;
1462  }
1463  av_assert0(stream_index>= 0);
1464 
1465  st = s->streams[stream_index];
1466  ast= st->priv_data;
1467  index= av_index_search_timestamp(st, timestamp * FFMAX(ast->sample_size, 1), flags);
1468  if (index<0) {
1469  if (st->nb_index_entries > 0)
1470  av_log(s, AV_LOG_DEBUG, "Failed to find timestamp %"PRId64 " in index %"PRId64 " .. %"PRId64 "\n",
1471  timestamp * FFMAX(ast->sample_size, 1),
1472  st->index_entries[0].timestamp,
1474  return AVERROR_INVALIDDATA;
1475  }
1476 
1477  /* find the position */
1478  pos = st->index_entries[index].pos;
1479  timestamp = st->index_entries[index].timestamp / FFMAX(ast->sample_size, 1);
1480 
1481  av_dlog(s, "XX %"PRId64" %d %"PRId64"\n",
1482  timestamp, index, st->index_entries[index].timestamp);
1483 
1484  if (CONFIG_DV_DEMUXER && avi->dv_demux) {
1485  /* One and only one real stream for DV in AVI, and it has video */
1486  /* offsets. Calling with other stream indexes should have failed */
1487  /* the av_index_search_timestamp call above. */
1488  av_assert0(stream_index == 0);
1489 
1490  if(avio_seek(s->pb, pos, SEEK_SET) < 0)
1491  return -1;
1492 
1493  /* Feed the DV video stream version of the timestamp to the */
1494  /* DV demux so it can synthesize correct timestamps. */
1495  ff_dv_offset_reset(avi->dv_demux, timestamp);
1496 
1497  avi->stream_index= -1;
1498  return 0;
1499  }
1500 
1501  pos_min= pos;
1502  for(i = 0; i < s->nb_streams; i++) {
1503  AVStream *st2 = s->streams[i];
1504  AVIStream *ast2 = st2->priv_data;
1505 
1506  ast2->packet_size=
1507  ast2->remaining= 0;
1508 
1509  if (ast2->sub_ctx) {
1510  seek_subtitle(st, st2, timestamp);
1511  continue;
1512  }
1513 
1514  if (st2->nb_index_entries <= 0)
1515  continue;
1516 
1517 // av_assert1(st2->codec->block_align);
1518  av_assert0((int64_t)st2->time_base.num*ast2->rate == (int64_t)st2->time_base.den*ast2->scale);
1519  index = av_index_search_timestamp(
1520  st2,
1521  av_rescale_q(timestamp, st->time_base, st2->time_base) * FFMAX(ast2->sample_size, 1),
1523  if(index<0)
1524  index=0;
1525  ast2->seek_pos= st2->index_entries[index].pos;
1526  pos_min= FFMIN(pos_min,ast2->seek_pos);
1527  }
1528  for(i = 0; i < s->nb_streams; i++) {
1529  AVStream *st2 = s->streams[i];
1530  AVIStream *ast2 = st2->priv_data;
1531 
1532  if (ast2->sub_ctx || st2->nb_index_entries <= 0)
1533  continue;
1534 
1535  index = av_index_search_timestamp(
1536  st2,
1537  av_rescale_q(timestamp, st->time_base, st2->time_base) * FFMAX(ast2->sample_size, 1),
1539  if(index<0)
1540  index=0;
1541  while(!avi->non_interleaved && index>0 && st2->index_entries[index-1].pos >= pos_min)
1542  index--;
1543  ast2->frame_offset = st2->index_entries[index].timestamp;
1544  }
1545 
1546  /* do the seek */
1547  if (avio_seek(s->pb, pos_min, SEEK_SET) < 0) {
1548  av_log(s, AV_LOG_ERROR, "Seek failed\n");
1549  return -1;
1550  }
1551  avi->stream_index= -1;
1552  avi->dts_max= INT_MIN;
1553  return 0;
1554 }
1555 
1557 {
1558  int i;
1559  AVIContext *avi = s->priv_data;
1560 
1561  for(i=0;i<s->nb_streams;i++) {
1562  AVStream *st = s->streams[i];
1563  AVIStream *ast = st->priv_data;
1564  if (ast) {
1565  if (ast->sub_ctx) {
1566  av_freep(&ast->sub_ctx->pb);
1568  }
1569  av_free(ast->sub_buffer);
1570  av_free_packet(&ast->sub_pkt);
1571  }
1572  }
1573 
1574  av_free(avi->dv_demux);
1575 
1576  return 0;
1577 }
1578 
1579 static int avi_probe(AVProbeData *p)
1580 {
1581  int i;
1582 
1583  /* check file header */
1584  for(i=0; avi_headers[i][0]; i++)
1585  if(!memcmp(p->buf , avi_headers[i] , 4) &&
1586  !memcmp(p->buf+8, avi_headers[i]+4, 4))
1587  return AVPROBE_SCORE_MAX;
1588 
1589  return 0;
1590 }
1591 
1593  .name = "avi",
1594  .long_name = NULL_IF_CONFIG_SMALL("AVI (Audio Video Interleaved)"),
1595  .priv_data_size = sizeof(AVIContext),
1596  .read_probe = avi_probe,
1601  .priv_class = &demuxer_class,
1602 };