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flvdec.c
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1 /*
2  * FLV demuxer
3  * Copyright (c) 2003 The FFmpeg Project
4  *
5  * This demuxer will generate a 1 byte extradata for VP6F content.
6  * It is composed of:
7  * - upper 4bits: difference between encoded width and visible width
8  * - lower 4bits: difference between encoded height and visible height
9  *
10  * This file is part of FFmpeg.
11  *
12  * FFmpeg is free software; you can redistribute it and/or
13  * modify it under the terms of the GNU Lesser General Public
14  * License as published by the Free Software Foundation; either
15  * version 2.1 of the License, or (at your option) any later version.
16  *
17  * FFmpeg is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20  * Lesser General Public License for more details.
21  *
22  * You should have received a copy of the GNU Lesser General Public
23  * License along with FFmpeg; if not, write to the Free Software
24  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25  */
26 
27 #include "libavutil/avstring.h"
29 #include "libavutil/dict.h"
30 #include "libavutil/opt.h"
31 #include "libavutil/intfloat.h"
32 #include "libavutil/mathematics.h"
33 #include "libavcodec/bytestream.h"
34 #include "libavcodec/mpeg4audio.h"
35 #include "avformat.h"
36 #include "internal.h"
37 #include "avio_internal.h"
38 #include "flv.h"
39 
40 #define VALIDATE_INDEX_TS_THRESH 2500
41 
42 typedef struct {
43  const AVClass *class; ///< Class for private options.
44  int trust_metadata; ///< configure streams according onMetaData
45  int wrong_dts; ///< wrong dts due to negative cts
46  uint8_t *new_extradata[FLV_STREAM_TYPE_NB];
47  int new_extradata_size[FLV_STREAM_TYPE_NB];
50  struct {
51  int64_t dts;
52  int64_t pos;
53  } validate_index[2];
57 } FLVContext;
58 
59 static int flv_probe(AVProbeData *p)
60 {
61  const uint8_t *d;
62 
63  d = p->buf;
64  if (d[0] == 'F' && d[1] == 'L' && d[2] == 'V' && d[3] < 5 && d[5]==0 && AV_RB32(d+5)>8) {
65  return AVPROBE_SCORE_MAX;
66  }
67  return 0;
68 }
69 
71 {
73  if (!st)
74  return NULL;
76  if(s->nb_streams>=3 ||( s->nb_streams==2
80 
81  avpriv_set_pts_info(st, 32, 1, 1000); /* 32 bit pts in ms */
82  return st;
83 }
84 static int flv_same_audio_codec(AVCodecContext *acodec, int flags)
85 {
86  int bits_per_coded_sample = (flags & FLV_AUDIO_SAMPLESIZE_MASK) ? 16 : 8;
87  int flv_codecid = flags & FLV_AUDIO_CODECID_MASK;
88  int codec_id;
89 
90  if (!acodec->codec_id && !acodec->codec_tag)
91  return 1;
92 
93  if (acodec->bits_per_coded_sample != bits_per_coded_sample)
94  return 0;
95 
96  switch(flv_codecid) {
97  //no distinction between S16 and S8 PCM codec flags
98  case FLV_CODECID_PCM:
99  codec_id = bits_per_coded_sample == 8 ? AV_CODEC_ID_PCM_U8 :
100 #if HAVE_BIGENDIAN
102 #else
104 #endif
105  return codec_id == acodec->codec_id;
106  case FLV_CODECID_PCM_LE:
107  codec_id = bits_per_coded_sample == 8 ? AV_CODEC_ID_PCM_U8 : AV_CODEC_ID_PCM_S16LE;
108  return codec_id == acodec->codec_id;
109  case FLV_CODECID_AAC:
110  return acodec->codec_id == AV_CODEC_ID_AAC;
111  case FLV_CODECID_ADPCM:
112  return acodec->codec_id == AV_CODEC_ID_ADPCM_SWF;
113  case FLV_CODECID_SPEEX:
114  return acodec->codec_id == AV_CODEC_ID_SPEEX;
115  case FLV_CODECID_MP3:
116  return acodec->codec_id == AV_CODEC_ID_MP3;
120  return acodec->codec_id == AV_CODEC_ID_NELLYMOSER;
122  return acodec->sample_rate == 8000 &&
123  acodec->codec_id == AV_CODEC_ID_PCM_MULAW;
125  return acodec->sample_rate = 8000 &&
126  acodec->codec_id == AV_CODEC_ID_PCM_ALAW;
127  default:
128  return acodec->codec_tag == (flv_codecid >> FLV_AUDIO_CODECID_OFFSET);
129  }
130 }
131 
132 static void flv_set_audio_codec(AVFormatContext *s, AVStream *astream, AVCodecContext *acodec, int flv_codecid) {
133  switch(flv_codecid) {
134  //no distinction between S16 and S8 PCM codec flags
135  case FLV_CODECID_PCM:
136  acodec->codec_id = acodec->bits_per_coded_sample == 8 ? AV_CODEC_ID_PCM_U8 :
137 #if HAVE_BIGENDIAN
139 #else
141 #endif
142  break;
143  case FLV_CODECID_PCM_LE:
145  case FLV_CODECID_AAC : acodec->codec_id = AV_CODEC_ID_AAC; break;
146  case FLV_CODECID_ADPCM: acodec->codec_id = AV_CODEC_ID_ADPCM_SWF; break;
147  case FLV_CODECID_SPEEX:
148  acodec->codec_id = AV_CODEC_ID_SPEEX;
149  acodec->sample_rate = 16000;
150  break;
151  case FLV_CODECID_MP3 : acodec->codec_id = AV_CODEC_ID_MP3 ; astream->need_parsing = AVSTREAM_PARSE_FULL; break;
153  acodec->sample_rate = 8000; //in case metadata does not otherwise declare samplerate
155  break;
157  acodec->sample_rate = 16000;
159  break;
162  break;
164  acodec->sample_rate = 8000;
166  break;
168  acodec->sample_rate = 8000;
169  acodec->codec_id = AV_CODEC_ID_PCM_ALAW;
170  break;
171  default:
172  av_log(s, AV_LOG_INFO, "Unsupported audio codec (%x)\n", flv_codecid >> FLV_AUDIO_CODECID_OFFSET);
173  acodec->codec_tag = flv_codecid >> FLV_AUDIO_CODECID_OFFSET;
174  }
175 }
176 
177 static int flv_same_video_codec(AVCodecContext *vcodec, int flags)
178 {
179  int flv_codecid = flags & FLV_VIDEO_CODECID_MASK;
180 
181  if (!vcodec->codec_id && !vcodec->codec_tag)
182  return 1;
183 
184  switch (flv_codecid) {
185  case FLV_CODECID_H263:
186  return vcodec->codec_id == AV_CODEC_ID_FLV1;
187  case FLV_CODECID_SCREEN:
188  return vcodec->codec_id == AV_CODEC_ID_FLASHSV;
189  case FLV_CODECID_SCREEN2:
190  return vcodec->codec_id == AV_CODEC_ID_FLASHSV2;
191  case FLV_CODECID_VP6:
192  return vcodec->codec_id == AV_CODEC_ID_VP6F;
193  case FLV_CODECID_VP6A:
194  return vcodec->codec_id == AV_CODEC_ID_VP6A;
195  case FLV_CODECID_H264:
196  return vcodec->codec_id == AV_CODEC_ID_H264;
197  default:
198  return vcodec->codec_tag == flv_codecid;
199  }
200 }
201 
202 static int flv_set_video_codec(AVFormatContext *s, AVStream *vstream, int flv_codecid, int read) {
203  AVCodecContext *vcodec = vstream->codec;
204  switch(flv_codecid) {
205  case FLV_CODECID_H263 : vcodec->codec_id = AV_CODEC_ID_FLV1 ; break;
206  case FLV_CODECID_REALH263: vcodec->codec_id = AV_CODEC_ID_H263 ; break; // Really mean it this time
207  case FLV_CODECID_SCREEN: vcodec->codec_id = AV_CODEC_ID_FLASHSV; break;
208  case FLV_CODECID_SCREEN2: vcodec->codec_id = AV_CODEC_ID_FLASHSV2; break;
209  case FLV_CODECID_VP6 : vcodec->codec_id = AV_CODEC_ID_VP6F ;
210  case FLV_CODECID_VP6A :
211  if(flv_codecid == FLV_CODECID_VP6A)
212  vcodec->codec_id = AV_CODEC_ID_VP6A;
213  if (read) {
214  if (vcodec->extradata_size != 1) {
216  if (vcodec->extradata)
217  vcodec->extradata_size = 1;
218  }
219  if (vcodec->extradata)
220  vcodec->extradata[0] = avio_r8(s->pb);
221  else
222  avio_skip(s->pb, 1);
223  }
224  return 1; // 1 byte body size adjustment for flv_read_packet()
225  case FLV_CODECID_H264:
226  vcodec->codec_id = AV_CODEC_ID_H264;
227  return 3; // not 4, reading packet type will consume one byte
228  case FLV_CODECID_MPEG4:
229  vcodec->codec_id = AV_CODEC_ID_MPEG4;
230  return 3;
231  default:
232  av_log(s, AV_LOG_INFO, "Unsupported video codec (%x)\n", flv_codecid);
233  vcodec->codec_tag = flv_codecid;
234  }
235 
236  return 0;
237 }
238 
239 static int amf_get_string(AVIOContext *ioc, char *buffer, int buffsize) {
240  int length = avio_rb16(ioc);
241  if(length >= buffsize) {
242  avio_skip(ioc, length);
243  return -1;
244  }
245 
246  avio_read(ioc, buffer, length);
247 
248  buffer[length] = '\0';
249 
250  return length;
251 }
252 
253 static int parse_keyframes_index(AVFormatContext *s, AVIOContext *ioc, AVStream *vstream, int64_t max_pos) {
254  FLVContext *flv = s->priv_data;
255  unsigned int timeslen = 0, fileposlen = 0, i;
256  char str_val[256];
257  int64_t *times = NULL;
258  int64_t *filepositions = NULL;
259  int ret = AVERROR(ENOSYS);
260  int64_t initial_pos = avio_tell(ioc);
261 
262  if(vstream->nb_index_entries>0){
263  av_log(s, AV_LOG_WARNING, "Skiping duplicate index\n");
264  return 0;
265  }
266 
267  if (s->flags & AVFMT_FLAG_IGNIDX)
268  return 0;
269 
270  while (avio_tell(ioc) < max_pos - 2 && amf_get_string(ioc, str_val, sizeof(str_val)) > 0) {
271  int64_t** current_array;
272  unsigned int arraylen;
273 
274  // Expect array object in context
275  if (avio_r8(ioc) != AMF_DATA_TYPE_ARRAY)
276  break;
277 
278  arraylen = avio_rb32(ioc);
279  if(arraylen>>28)
280  break;
281 
282  if (!strcmp(KEYFRAMES_TIMESTAMP_TAG , str_val) && !times){
283  current_array= &times;
284  timeslen= arraylen;
285  }else if (!strcmp(KEYFRAMES_BYTEOFFSET_TAG, str_val) && !filepositions){
286  current_array= &filepositions;
287  fileposlen= arraylen;
288  }else // unexpected metatag inside keyframes, will not use such metadata for indexing
289  break;
290 
291  if (!(*current_array = av_mallocz(sizeof(**current_array) * arraylen))) {
292  ret = AVERROR(ENOMEM);
293  goto finish;
294  }
295 
296  for (i = 0; i < arraylen && avio_tell(ioc) < max_pos - 1; i++) {
297  if (avio_r8(ioc) != AMF_DATA_TYPE_NUMBER)
298  goto invalid;
299  current_array[0][i] = av_int2double(avio_rb64(ioc));
300  }
301  if (times && filepositions) {
302  // All done, exiting at a position allowing amf_parse_object
303  // to finish parsing the object
304  ret = 0;
305  break;
306  }
307  }
308 
309  if (timeslen == fileposlen && fileposlen>1 && max_pos <= filepositions[0]) {
310  for (i = 0; i < fileposlen; i++) {
311  av_add_index_entry(vstream, filepositions[i], times[i]*1000,
312  0, 0, AVINDEX_KEYFRAME);
313  if (i < 2) {
314  flv->validate_index[i].pos = filepositions[i];
315  flv->validate_index[i].dts = times[i] * 1000;
316  flv->validate_count = i + 1;
317  }
318  }
319  } else {
320 invalid:
321  av_log(s, AV_LOG_WARNING, "Invalid keyframes object, skipping.\n");
322  }
323 
324 finish:
325  av_freep(&times);
326  av_freep(&filepositions);
327  avio_seek(ioc, initial_pos, SEEK_SET);
328  return ret;
329 }
330 
331 static int amf_parse_object(AVFormatContext *s, AVStream *astream, AVStream *vstream, const char *key, int64_t max_pos, int depth) {
332  AVCodecContext *acodec, *vcodec;
333  FLVContext *flv = s->priv_data;
334  AVIOContext *ioc;
335  AMFDataType amf_type;
336  char str_val[256];
337  double num_val;
338 
339  num_val = 0;
340  ioc = s->pb;
341 
342  amf_type = avio_r8(ioc);
343 
344  switch(amf_type) {
346  num_val = av_int2double(avio_rb64(ioc)); break;
347  case AMF_DATA_TYPE_BOOL:
348  num_val = avio_r8(ioc); break;
350  if(amf_get_string(ioc, str_val, sizeof(str_val)) < 0)
351  return -1;
352  break;
354  if ((vstream || astream) && ioc->seekable && key && !strcmp(KEYFRAMES_TAG, key) && depth == 1)
355  if (parse_keyframes_index(s, ioc, vstream ? vstream : astream,
356  max_pos) < 0)
357  av_log(s, AV_LOG_ERROR, "Keyframe index parsing failed\n");
358 
359  while (avio_tell(ioc) < max_pos - 2 && amf_get_string(ioc, str_val, sizeof(str_val)) > 0) {
360  if (amf_parse_object(s, astream, vstream, str_val, max_pos, depth + 1) < 0)
361  return -1; //if we couldn't skip, bomb out.
362  }
363  if(avio_r8(ioc) != AMF_END_OF_OBJECT)
364  return -1;
365  break;
366  case AMF_DATA_TYPE_NULL:
369  break; //these take up no additional space
371  avio_skip(ioc, 4); //skip 32-bit max array index
372  while(avio_tell(ioc) < max_pos - 2 && amf_get_string(ioc, str_val, sizeof(str_val)) > 0) {
373  //this is the only case in which we would want a nested parse to not skip over the object
374  if(amf_parse_object(s, astream, vstream, str_val, max_pos, depth + 1) < 0)
375  return -1;
376  }
377  if(avio_r8(ioc) != AMF_END_OF_OBJECT)
378  return -1;
379  break;
380  case AMF_DATA_TYPE_ARRAY: {
381  unsigned int arraylen, i;
382 
383  arraylen = avio_rb32(ioc);
384  for(i = 0; i < arraylen && avio_tell(ioc) < max_pos - 1; i++) {
385  if(amf_parse_object(s, NULL, NULL, NULL, max_pos, depth + 1) < 0)
386  return -1; //if we couldn't skip, bomb out.
387  }
388  }
389  break;
390  case AMF_DATA_TYPE_DATE:
391  avio_skip(ioc, 8 + 2); //timestamp (double) and UTC offset (int16)
392  break;
393  default: //unsupported type, we couldn't skip
394  return -1;
395  }
396 
397  if(depth == 1 && key) { //only look for metadata values when we are not nested and key != NULL
398  acodec = astream ? astream->codec : NULL;
399  vcodec = vstream ? vstream->codec : NULL;
400 
401  if (amf_type == AMF_DATA_TYPE_NUMBER || amf_type == AMF_DATA_TYPE_BOOL) {
402  if (!strcmp(key, "duration"))
403  s->duration = num_val * AV_TIME_BASE;
404  else if (!strcmp(key, "videodatarate") && vcodec && 0 <= (int)(num_val * 1024.0))
405  vcodec->bit_rate = num_val * 1024.0;
406  else if (!strcmp(key, "audiodatarate") && acodec && 0 <= (int)(num_val * 1024.0))
407  acodec->bit_rate = num_val * 1024.0;
408  else if (!strcmp(key, "datastream")) {
410  if (!st)
411  return AVERROR(ENOMEM);
413  } else if (flv->trust_metadata) {
414  if (!strcmp(key, "videocodecid") && vcodec) {
415  flv_set_video_codec(s, vstream, num_val, 0);
416  } else
417  if (!strcmp(key, "audiocodecid") && acodec) {
418  int id = ((int)num_val) << FLV_AUDIO_CODECID_OFFSET;
419  flv_set_audio_codec(s, astream, acodec, id);
420  } else
421  if (!strcmp(key, "audiosamplerate") && acodec) {
422  acodec->sample_rate = num_val;
423  } else if (!strcmp(key, "audiosamplesize") && acodec) {
424  acodec->bits_per_coded_sample = num_val;
425  } else if (!strcmp(key, "stereo") && acodec) {
426  acodec->channels = num_val + 1;
427  acodec->channel_layout = acodec->channels == 2 ?
430  } else
431  if (!strcmp(key, "width") && vcodec) {
432  vcodec->width = num_val;
433  } else
434  if (!strcmp(key, "height") && vcodec) {
435  vcodec->height = num_val;
436  }
437  }
438  }
439 
440  if (amf_type == AMF_DATA_TYPE_OBJECT && s->nb_streams == 1 &&
441  ((!acodec && !strcmp(key, "audiocodecid")) ||
442  (!vcodec && !strcmp(key, "videocodecid"))))
443  s->ctx_flags &= ~AVFMTCTX_NOHEADER; //If there is either audio/video missing, codecid will be an empty object
444 
445  if (!strcmp(key, "duration") ||
446  !strcmp(key, "filesize") ||
447  !strcmp(key, "width") ||
448  !strcmp(key, "height") ||
449  !strcmp(key, "videodatarate") ||
450  !strcmp(key, "framerate") ||
451  !strcmp(key, "videocodecid") ||
452  !strcmp(key, "audiodatarate") ||
453  !strcmp(key, "audiosamplerate") ||
454  !strcmp(key, "audiosamplesize") ||
455  !strcmp(key, "stereo") ||
456  !strcmp(key, "audiocodecid"))
457  return 0;
458 
459  if(amf_type == AMF_DATA_TYPE_BOOL) {
460  av_strlcpy(str_val, num_val > 0 ? "true" : "false", sizeof(str_val));
461  av_dict_set(&s->metadata, key, str_val, 0);
462  } else if(amf_type == AMF_DATA_TYPE_NUMBER) {
463  snprintf(str_val, sizeof(str_val), "%.f", num_val);
464  av_dict_set(&s->metadata, key, str_val, 0);
465  } else if (amf_type == AMF_DATA_TYPE_STRING)
466  av_dict_set(&s->metadata, key, str_val, 0);
467  }
468 
469  return 0;
470 }
471 
472 static int flv_read_metabody(AVFormatContext *s, int64_t next_pos) {
473  AMFDataType type;
474  AVStream *stream, *astream, *vstream, *dstream;
475  AVIOContext *ioc;
476  int i;
477  char buffer[11]; //only needs to hold the string "onMetaData". Anything longer is something we don't want.
478 
479  vstream = astream = dstream = NULL;
480  ioc = s->pb;
481 
482  //first object needs to be "onMetaData" string
483  type = avio_r8(ioc);
484  if (type != AMF_DATA_TYPE_STRING ||
485  amf_get_string(ioc, buffer, sizeof(buffer)) < 0)
486  return -1;
487 
488  if (!strcmp(buffer, "onTextData"))
489  return 1;
490 
491  if (strcmp(buffer, "onMetaData"))
492  return -1;
493 
494  //find the streams now so that amf_parse_object doesn't need to do the lookup every time it is called.
495  for(i = 0; i < s->nb_streams; i++) {
496  stream = s->streams[i];
497  if(stream->codec->codec_type == AVMEDIA_TYPE_VIDEO) vstream = stream;
498  else if(stream->codec->codec_type == AVMEDIA_TYPE_AUDIO) astream = stream;
499  else if(stream->codec->codec_type == AVMEDIA_TYPE_DATA) dstream = stream;
500  }
501 
502  //parse the second object (we want a mixed array)
503  if(amf_parse_object(s, astream, vstream, buffer, next_pos, 0) < 0)
504  return -1;
505 
506  return 0;
507 }
508 
510 {
511  int offset, flags;
512 
513  avio_skip(s->pb, 4);
514  flags = avio_r8(s->pb);
515  /* old flvtool cleared this field */
516  /* FIXME: better fix needed */
517  if (!flags) {
519  av_log(s, AV_LOG_WARNING, "Broken FLV file, which says no streams present, this might fail\n");
520  }
521 
523 
524  if(flags & FLV_HEADER_FLAG_HASVIDEO){
526  return AVERROR(ENOMEM);
527  }
528  if(flags & FLV_HEADER_FLAG_HASAUDIO){
530  return AVERROR(ENOMEM);
531  }
532  // Flag doesn't indicate whether or not there is script-data present. Must
533  // create that stream if it's encountered.
534 
535  offset = avio_rb32(s->pb);
536  avio_seek(s->pb, offset, SEEK_SET);
537  avio_skip(s->pb, 4);
538 
539  s->start_time = 0;
540 
541  return 0;
542 }
543 
545 {
546  int i;
547  FLVContext *flv = s->priv_data;
548  for(i=0; i<FLV_STREAM_TYPE_NB; i++)
549  av_freep(&flv->new_extradata[i]);
550  return 0;
551 }
552 
554 {
555  av_free(st->codec->extradata);
557  if (!st->codec->extradata)
558  return AVERROR(ENOMEM);
559  st->codec->extradata_size = size;
561  return 0;
562 }
563 
564 static int flv_queue_extradata(FLVContext *flv, AVIOContext *pb, int stream,
565  int size)
566 {
567  av_free(flv->new_extradata[stream]);
569  if (!flv->new_extradata[stream])
570  return AVERROR(ENOMEM);
571  flv->new_extradata_size[stream] = size;
572  avio_read(pb, flv->new_extradata[stream], size);
573  return 0;
574 }
575 
576 static void clear_index_entries(AVFormatContext *s, int64_t pos)
577 {
578  int i, j, out;
579  av_log(s, AV_LOG_WARNING, "Found invalid index entries, clearing the index.\n");
580  for (i = 0; i < s->nb_streams; i++) {
581  AVStream *st = s->streams[i];
582  /* Remove all index entries that point to >= pos */
583  out = 0;
584  for (j = 0; j < st->nb_index_entries; j++) {
585  if (st->index_entries[j].pos < pos)
586  st->index_entries[out++] = st->index_entries[j];
587  }
588  st->nb_index_entries = out;
589  }
590 }
591 
592 
594  int64_t dts, int64_t next)
595 {
596  int ret = AVERROR_INVALIDDATA, i;
597  AVIOContext *pb = s->pb;
598  AVStream *st = NULL;
599  AMFDataType type;
600  char buf[20];
601  int length;
602 
603  type = avio_r8(pb);
604  if (type == AMF_DATA_TYPE_MIXEDARRAY)
605  avio_seek(pb, 4, SEEK_CUR);
606  else if (type != AMF_DATA_TYPE_OBJECT)
607  goto out;
608 
609  amf_get_string(pb, buf, sizeof(buf));
610  if (strcmp(buf, "type") || avio_r8(pb) != AMF_DATA_TYPE_STRING)
611  goto out;
612 
613  amf_get_string(pb, buf, sizeof(buf));
614  //FIXME parse it as codec_id
615  amf_get_string(pb, buf, sizeof(buf));
616  if (strcmp(buf, "text") || avio_r8(pb) != AMF_DATA_TYPE_STRING)
617  goto out;
618 
619  length = avio_rb16(pb);
620  ret = av_get_packet(s->pb, pkt, length);
621  if (ret < 0) {
622  ret = AVERROR(EIO);
623  goto out;
624  }
625 
626  for (i = 0; i < s->nb_streams; i++) {
627  st = s->streams[i];
628  if (st->codec->codec_type == AVMEDIA_TYPE_DATA)
629  break;
630  }
631 
632  if (i == s->nb_streams) {
634  if (!st)
635  goto out;
637  }
638 
639  pkt->dts = dts;
640  pkt->pts = dts;
641  pkt->size = ret;
642 
643  pkt->stream_index = st->index;
644  pkt->flags |= AV_PKT_FLAG_KEY;
645 
646  avio_seek(s->pb, next + 4, SEEK_SET);
647 out:
648  return ret;
649 }
650 
652 {
653  FLVContext *flv = s->priv_data;
654  int ret, i, type, size, flags;
655  int stream_type=-1;
656  int64_t next, pos;
657  int64_t dts, pts = AV_NOPTS_VALUE;
658  int av_uninit(channels);
659  int av_uninit(sample_rate);
660  AVStream *st = NULL;
661 
662  for(;;avio_skip(s->pb, 4)){ /* pkt size is repeated at end. skip it */
663  pos = avio_tell(s->pb);
664  type = avio_r8(s->pb);
665  size = avio_rb24(s->pb);
666  dts = avio_rb24(s->pb);
667  dts |= avio_r8(s->pb) << 24;
668  av_dlog(s, "type:%d, size:%d, dts:%"PRId64"\n", type, size, dts);
669  if (url_feof(s->pb))
670  return AVERROR_EOF;
671  avio_skip(s->pb, 3); /* stream id, always 0 */
672  flags = 0;
673 
674  if (flv->validate_next < flv->validate_count) {
675  int64_t validate_pos = flv->validate_index[flv->validate_next].pos;
676  if (pos == validate_pos) {
677  if (FFABS(dts - flv->validate_index[flv->validate_next].dts) <=
679  flv->validate_next++;
680  } else {
681  clear_index_entries(s, validate_pos);
682  flv->validate_count = 0;
683  }
684  } else if (pos > validate_pos) {
685  clear_index_entries(s, validate_pos);
686  flv->validate_count = 0;
687  }
688  }
689 
690  if(size == 0)
691  continue;
692 
693  next= size + avio_tell(s->pb);
694 
695  if (type == FLV_TAG_TYPE_AUDIO) {
696  stream_type=FLV_STREAM_TYPE_AUDIO;
697  flags = avio_r8(s->pb);
698  size--;
699  } else if (type == FLV_TAG_TYPE_VIDEO) {
700  stream_type=FLV_STREAM_TYPE_VIDEO;
701  flags = avio_r8(s->pb);
702  size--;
704  goto skip;
705  } else if (type == FLV_TAG_TYPE_META) {
706  if (size > 13+1+4 && dts == 0) { // Header-type metadata stuff
707  flv_read_metabody(s, next);
708  goto skip;
709  } else if (dts != 0) { // Script-data "special" metadata frames - don't skip
710  stream_type=FLV_STREAM_TYPE_DATA;
711  } else {
712  goto skip;
713  }
714  } else {
715  av_log(s, AV_LOG_DEBUG, "skipping flv packet: type %d, size %d, flags %d\n", type, size, flags);
716  skip:
717  avio_seek(s->pb, next, SEEK_SET);
718  continue;
719  }
720 
721  /* skip empty data packets */
722  if (!size)
723  continue;
724 
725  /* now find stream */
726  for(i=0;i<s->nb_streams;i++) {
727  st = s->streams[i];
728  if (stream_type == FLV_STREAM_TYPE_AUDIO) {
729  if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO &&
730  (s->audio_codec_id || flv_same_audio_codec(st->codec, flags))) {
731  break;
732  }
733  } else
734  if (stream_type == FLV_STREAM_TYPE_VIDEO) {
735  if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO &&
736  (s->video_codec_id || flv_same_video_codec(st->codec, flags))) {
737  break;
738  }
739  } else if (stream_type == FLV_STREAM_TYPE_DATA) {
740  if (st->codec->codec_type == AVMEDIA_TYPE_DATA)
741  break;
742  }
743  }
744  if(i == s->nb_streams){
745  av_log(s, AV_LOG_WARNING, "Stream discovered after head already parsed\n");
746  st = create_stream(s,
748  if (!st)
749  return AVERROR(ENOMEM);
750 
751  }
752  av_dlog(s, "%d %X %d \n", stream_type, flags, st->discard);
753  if( (st->discard >= AVDISCARD_NONKEY && !((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY || (stream_type == FLV_STREAM_TYPE_AUDIO)))
754  ||(st->discard >= AVDISCARD_BIDIR && ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_DISP_INTER && (stream_type == FLV_STREAM_TYPE_VIDEO)))
755  || st->discard >= AVDISCARD_ALL
756  ){
757  avio_seek(s->pb, next, SEEK_SET);
758  continue;
759  }
760  if ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY)
761  av_add_index_entry(st, pos, dts, size, 0, AVINDEX_KEYFRAME);
762  break;
763  }
764 
765  // if not streamed and no duration from metadata then seek to end to find the duration from the timestamps
766  if(s->pb->seekable && (!s->duration || s->duration==AV_NOPTS_VALUE) && !flv->searched_for_end){
767  int size;
768  const int64_t pos= avio_tell(s->pb);
769  int64_t fsize= avio_size(s->pb);
770 retry_duration:
771  avio_seek(s->pb, fsize-4, SEEK_SET);
772  size= avio_rb32(s->pb);
773  avio_seek(s->pb, fsize-3-size, SEEK_SET);
774  if(size == avio_rb24(s->pb) + 11){
775  uint32_t ts = avio_rb24(s->pb);
776  ts |= avio_r8(s->pb) << 24;
777  if(ts)
778  s->duration = ts * (int64_t)AV_TIME_BASE / 1000;
779  else if (fsize >= 8 && fsize - 8 >= size){
780  fsize -= size+4;
781  goto retry_duration;
782  }
783  }
784 
785  avio_seek(s->pb, pos, SEEK_SET);
786  flv->searched_for_end = 1;
787  }
788 
789  if(stream_type == FLV_STREAM_TYPE_AUDIO){
790  int bits_per_coded_sample;
791  channels = (flags & FLV_AUDIO_CHANNEL_MASK) == FLV_STEREO ? 2 : 1;
792  sample_rate = (44100 << ((flags & FLV_AUDIO_SAMPLERATE_MASK) >> FLV_AUDIO_SAMPLERATE_OFFSET) >> 3);
793  bits_per_coded_sample = (flags & FLV_AUDIO_SAMPLESIZE_MASK) ? 16 : 8;
794  if(!st->codec->channels || !st->codec->sample_rate || !st->codec->bits_per_coded_sample) {
795  st->codec->channels = channels;
796  st->codec->channel_layout = channels == 1 ? AV_CH_LAYOUT_MONO :
799  st->codec->bits_per_coded_sample = bits_per_coded_sample;
800  }
801  if(!st->codec->codec_id){
802  flv_set_audio_codec(s, st, st->codec, flags & FLV_AUDIO_CODECID_MASK);
804  flv->last_channels = channels = st->codec->channels;
805  } else {
806  AVCodecContext ctx;
807  ctx.sample_rate = sample_rate;
808  flv_set_audio_codec(s, st, &ctx, flags & FLV_AUDIO_CODECID_MASK);
809  sample_rate = ctx.sample_rate;
810  }
811  } else if(stream_type == FLV_STREAM_TYPE_VIDEO) {
812  size -= flv_set_video_codec(s, st, flags & FLV_VIDEO_CODECID_MASK, 1);
813  }
814 
815  if (st->codec->codec_id == AV_CODEC_ID_AAC ||
816  st->codec->codec_id == AV_CODEC_ID_H264 ||
817  st->codec->codec_id == AV_CODEC_ID_MPEG4) {
818  int type = avio_r8(s->pb);
819  size--;
821  int32_t cts = (avio_rb24(s->pb)+0xff800000)^0xff800000; // sign extension
822  pts = dts + cts;
823  if (cts < 0) { // dts are wrong
824  flv->wrong_dts = 1;
825  av_log(s, AV_LOG_WARNING, "negative cts, previous timestamps might be wrong\n");
826  }
827  if (flv->wrong_dts)
828  dts = AV_NOPTS_VALUE;
829  }
830  if (type == 0 && (!st->codec->extradata || st->codec->codec_id == AV_CODEC_ID_AAC)) {
831  if (st->codec->extradata) {
832  if ((ret = flv_queue_extradata(flv, s->pb, stream_type, size)) < 0)
833  return ret;
834  ret = AVERROR(EAGAIN);
835  goto leave;
836  }
837  if ((ret = flv_get_extradata(s, st, size)) < 0)
838  return ret;
839  if (st->codec->codec_id == AV_CODEC_ID_AAC && 0) {
840  MPEG4AudioConfig cfg;
842  st->codec->extradata_size * 8, 1) >= 0) {
843  st->codec->channels = cfg.channels;
844  st->codec->channel_layout = 0;
845  if (cfg.ext_sample_rate)
846  st->codec->sample_rate = cfg.ext_sample_rate;
847  else
848  st->codec->sample_rate = cfg.sample_rate;
849  av_dlog(s, "mp4a config channels %d sample rate %d\n",
850  st->codec->channels, st->codec->sample_rate);
851  }
852  }
853 
854  ret = AVERROR(EAGAIN);
855  goto leave;
856  }
857  }
858 
859  /* skip empty data packets */
860  if (!size) {
861  ret = AVERROR(EAGAIN);
862  goto leave;
863  }
864 
865  ret= av_get_packet(s->pb, pkt, size);
866  if (ret < 0)
867  return ret;
868  pkt->dts = dts;
869  pkt->pts = pts == AV_NOPTS_VALUE ? dts : pts;
870  pkt->stream_index = st->index;
871  if (flv->new_extradata[stream_type]) {
873  flv->new_extradata_size[stream_type]);
874  if (side) {
875  memcpy(side, flv->new_extradata[stream_type],
876  flv->new_extradata_size[stream_type]);
877  av_freep(&flv->new_extradata[stream_type]);
878  flv->new_extradata_size[stream_type] = 0;
879  }
880  }
881  if (stream_type == FLV_STREAM_TYPE_AUDIO && (sample_rate != flv->last_sample_rate ||
882  channels != flv->last_channels)) {
884  flv->last_channels = channels;
885  ff_add_param_change(pkt, channels, 0, sample_rate, 0, 0);
886  }
887 
888  if ( stream_type == FLV_STREAM_TYPE_AUDIO ||
889  ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY) ||
890  stream_type == FLV_STREAM_TYPE_DATA)
891  pkt->flags |= AV_PKT_FLAG_KEY;
892 
893 leave:
894  avio_skip(s->pb, 4);
895  return ret;
896 }
897 
898 static int flv_read_seek(AVFormatContext *s, int stream_index,
899  int64_t ts, int flags)
900 {
901  FLVContext *flv = s->priv_data;
902  flv->validate_count = 0;
903  return avio_seek_time(s->pb, stream_index, ts, flags);
904 }
905 
906 #define OFFSET(x) offsetof(FLVContext, x)
907 #define VD AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_DECODING_PARAM
908 static const AVOption options[] = {
909  { "flv_metadata", "Allocate streams according the onMetaData array", OFFSET(trust_metadata), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, VD},
910  { NULL }
911 };
912 
913 static const AVClass class = {
914  .class_name = "flvdec",
915  .item_name = av_default_item_name,
916  .option = options,
918 };
919 
921  .name = "flv",
922  .long_name = NULL_IF_CONFIG_SMALL("FLV (Flash Video)"),
923  .priv_data_size = sizeof(FLVContext),
929  .extensions = "flv",
930  .priv_class = &class,
931 };