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1 @chapter Demuxers
2 @c man begin DEMUXERS
3
4 Demuxers are configured elements in FFmpeg that can read the
5 multimedia streams from a particular type of file.
6
7 When you configure your FFmpeg build, all the supported demuxers
8 are enabled by default. You can list all available ones using the
9 configure option @code{--list-demuxers}.
10
11 You can disable all the demuxers using the configure option
12 @code{--disable-demuxers}, and selectively enable a single demuxer with
13 the option @code{--enable-demuxer=@var{DEMUXER}}, or disable it
14 with the option @code{--disable-demuxer=@var{DEMUXER}}.
15
16 The option @code{-demuxers} of the ff* tools will display the list of
17 enabled demuxers. Use @code{-formats} to view a combined list of
18 enabled demuxers and muxers.
19
20 The description of some of the currently available demuxers follows.
21
22 @section aa
23
24 Audible Format 2, 3, and 4 demuxer.
25
26 This demuxer is used to demux Audible Format 2, 3, and 4 (.aa) files.
27
28 @section applehttp
29
30 Apple HTTP Live Streaming demuxer.
31
32 This demuxer presents all AVStreams from all variant streams.
33 The id field is set to the bitrate variant index number. By setting
34 the discard flags on AVStreams (by pressing 'a' or 'v' in ffplay),
35 the caller can decide which variant streams to actually receive.
36 The total bitrate of the variant that the stream belongs to is
37 available in a metadata key named "variant_bitrate".
38
39 @section apng
40
41 Animated Portable Network Graphics demuxer.
42
43 This demuxer is used to demux APNG files.
44 All headers, but the PNG signature, up to (but not including) the first
45 fcTL chunk are transmitted as extradata.
46 Frames are then split as being all the chunks between two fcTL ones, or
47 between the last fcTL and IEND chunks.
48
49 @table @option
50 @item -ignore_loop @var{bool}
51 Ignore the loop variable in the file if set.
52 @item -max_fps @var{int}
53 Maximum framerate in frames per second (0 for no limit).
54 @item -default_fps @var{int}
55 Default framerate in frames per second when none is specified in the file
56 (0 meaning as fast as possible).
57 @end table
58
59 @section asf
60
61 Advanced Systems Format demuxer.
62
63 This demuxer is used to demux ASF files and MMS network streams.
64
65 @table @option
66 @item -no_resync_search @var{bool}
67 Do not try to resynchronize by looking for a certain optional start code.
68 @end table
69
70 @anchor{concat}
71 @section concat
72
73 Virtual concatenation script demuxer.
74
75 This demuxer reads a list of files and other directives from a text file and
76 demuxes them one after the other, as if all their packets had been muxed
77 together.
78
79 The timestamps in the files are adjusted so that the first file starts at 0
80 and each next file starts where the previous one finishes. Note that it is
81 done globally and may cause gaps if all streams do not have exactly the same
82 length.
83
84 All files must have the same streams (same codecs, same time base, etc.).
85
86 The duration of each file is used to adjust the timestamps of the next file:
87 if the duration is incorrect (because it was computed using the bit-rate or
88 because the file is truncated, for example), it can cause artifacts. The
89 @code{duration} directive can be used to override the duration stored in
90 each file.
91
92 @subsection Syntax
93
94 The script is a text file in extended-ASCII, with one directive per line.
95 Empty lines, leading spaces and lines starting with '#' are ignored. The
96 following directive is recognized:
97
98 @table @option
99
100 @item @code{file @var{path}}
101 Path to a file to read; special characters and spaces must be escaped with
102 backslash or single quotes.
103
104 All subsequent file-related directives apply to that file.
105
106 @item @code{ffconcat version 1.0}
107 Identify the script type and version. It also sets the @option{safe} option
108 to 1 if it was -1.
109
110 To make FFmpeg recognize the format automatically, this directive must
111 appear exactly as is (no extra space or byte-order-mark) on the very first
112 line of the script.
113
114 @item @code{duration @var{dur}}
115 Duration of the file. This information can be specified from the file;
116 specifying it here may be more efficient or help if the information from the
117 file is not available or accurate.
118
119 If the duration is set for all files, then it is possible to seek in the
120 whole concatenated video.
121
122 @item @code{inpoint @var{timestamp}}
123 In point of the file. When the demuxer opens the file it instantly seeks to the
124 specified timestamp. Seeking is done so that all streams can be presented
125 successfully at In point.
126
127 This directive works best with intra frame codecs, because for non-intra frame
128 ones you will usually get extra packets before the actual In point and the
129 decoded content will most likely contain frames before In point too.
130
131 For each file, packets before the file In point will have timestamps less than
132 the calculated start timestamp of the file (negative in case of the first
133 file), and the duration of the files (if not specified by the @code{duration}
134 directive) will be reduced based on their specified In point.
135
136 Because of potential packets before the specified In point, packet timestamps
137 may overlap between two concatenated files.
138
139 @item @code{outpoint @var{timestamp}}
140 Out point of the file. When the demuxer reaches the specified decoding
141 timestamp in any of the streams, it handles it as an end of file condition and
142 skips the current and all the remaining packets from all streams.
143
144 Out point is exclusive, which means that the demuxer will not output packets
145 with a decoding timestamp greater or equal to Out point.
146
147 This directive works best with intra frame codecs and formats where all streams
148 are tightly interleaved. For non-intra frame codecs you will usually get
149 additional packets with presentation timestamp after Out point therefore the
150 decoded content will most likely contain frames after Out point too. If your
151 streams are not tightly interleaved you may not get all the packets from all
152 streams before Out point and you may only will be able to decode the earliest
153 stream until Out point.
154
155 The duration of the files (if not specified by the @code{duration}
156 directive) will be reduced based on their specified Out point.
157
158 @item @code{file_packet_metadata @var{key=value}}
159 Metadata of the packets of the file. The specified metadata will be set for
160 each file packet. You can specify this directive multiple times to add multiple
161 metadata entries.
162
163 @item @code{stream}
164 Introduce a stream in the virtual file.
165 All subsequent stream-related directives apply to the last introduced
166 stream.
167 Some streams properties must be set in order to allow identifying the
168 matching streams in the subfiles.
169 If no streams are defined in the script, the streams from the first file are
170 copied.
171
172 @item @code{exact_stream_id @var{id}}
173 Set the id of the stream.
174 If this directive is given, the string with the corresponding id in the
175 subfiles will be used.
176 This is especially useful for MPEG-PS (VOB) files, where the order of the
177 streams is not reliable.
178
179 @end table
180
181 @subsection Options
182
183 This demuxer accepts the following option:
184
185 @table @option
186
187 @item safe
188 If set to 1, reject unsafe file paths. A file path is considered safe if it
189 does not contain a protocol specification and is relative and all components
190 only contain characters from the portable character set (letters, digits,
191 period, underscore and hyphen) and have no period at the beginning of a
192 component.
193
194 If set to 0, any file name is accepted.
195
196 The default is 1.
197
198 -1 is equivalent to 1 if the format was automatically
199 probed and 0 otherwise.
200
201 @item auto_convert
202 If set to 1, try to perform automatic conversions on packet data to make the
203 streams concatenable.
204 The default is 1.
205
206 Currently, the only conversion is adding the h264_mp4toannexb bitstream
207 filter to H.264 streams in MP4 format. This is necessary in particular if
208 there are resolution changes.
209
210 @item segment_time_metadata
211 If set to 1, every packet will contain the @var{lavf.concat.start_time} and the
212 @var{lavf.concat.duration} packet metadata values which are the start_time and
213 the duration of the respective file segments in the concatenated output
214 expressed in microseconds. The duration metadata is only set if it is known
215 based on the concat file.
216 The default is 0.
217
218 @end table
219
220 @subsection Examples
221
222 @itemize
223 @item
224 Use absolute filenames and include some comments:
225 @example
226 # my first filename
227 file /mnt/share/file-1.wav
228 # my second filename including whitespace
229 file '/mnt/share/file 2.wav'
230 # my third filename including whitespace plus single quote
231 file '/mnt/share/file 3'\''.wav'
232 @end example
233
234 @item
235 Allow for input format auto-probing, use safe filenames and set the duration of
236 the first file:
237 @example
238 ffconcat version 1.0
239
240 file file-1.wav
241 duration 20.0
242
243 file subdir/file-2.wav
244 @end example
245 @end itemize
246
247 @section flv, live_flv
248
249 Adobe Flash Video Format demuxer.
250
251 This demuxer is used to demux FLV files and RTMP network streams. In case of live network streams, if you force format, you may use live_flv option instead of flv to survive timestamp discontinuities.
252
253 @example
254 ffmpeg -f flv -i myfile.flv ...
255 ffmpeg -f live_flv -i rtmp://<any.server>/anything/key ....
256 @end example
257
258
259 @table @option
260 @item -flv_metadata @var{bool}
261 Allocate the streams according to the onMetaData array content.
262 @end table
263
264 @section gif
265
266 Animated GIF demuxer.
267
268 It accepts the following options:
269
270 @table @option
271 @item min_delay
272 Set the minimum valid delay between frames in hundredths of seconds.
273 Range is 0 to 6000. Default value is 2.
274
275 @item max_gif_delay
276 Set the maximum valid delay between frames in hundredth of seconds.
277 Range is 0 to 65535. Default value is 65535 (nearly eleven minutes),
278 the maximum value allowed by the specification.
279
280 @item default_delay
281 Set the default delay between frames in hundredths of seconds.
282 Range is 0 to 6000. Default value is 10.
283
284 @item ignore_loop
285 GIF files can contain information to loop a certain number of times (or
286 infinitely). If @option{ignore_loop} is set to 1, then the loop setting
287 from the input will be ignored and looping will not occur. If set to 0,
288 then looping will occur and will cycle the number of times according to
289 the GIF. Default value is 1.
290 @end table
291
292 For example, with the overlay filter, place an infinitely looping GIF
293 over another video:
294 @example
295 ffmpeg -i input.mp4 -ignore_loop 0 -i input.gif -filter_complex overlay=shortest=1 out.mkv
296 @end example
297
298 Note that in the above example the shortest option for overlay filter is
299 used to end the output video at the length of the shortest input file,
300 which in this case is @file{input.mp4} as the GIF in this example loops
301 infinitely.
302
303 @section image2
304
305 Image file demuxer.
306
307 This demuxer reads from a list of image files specified by a pattern.
308 The syntax and meaning of the pattern is specified by the
309 option @var{pattern_type}.
310
311 The pattern may contain a suffix which is used to automatically
312 determine the format of the images contained in the files.
313
314 The size, the pixel format, and the format of each image must be the
315 same for all the files in the sequence.
316
317 This demuxer accepts the following options:
318 @table @option
319 @item framerate
320 Set the frame rate for the video stream. It defaults to 25.
321 @item loop
322 If set to 1, loop over the input. Default value is 0.
323 @item pattern_type
324 Select the pattern type used to interpret the provided filename.
325
326 @var{pattern_type} accepts one of the following values.
327 @table @option
328 @item none
329 Disable pattern matching, therefore the video will only contain the specified
330 image. You should use this option if you do not want to create sequences from
331 multiple images and your filenames may contain special pattern characters.
332 @item sequence
333 Select a sequence pattern type, used to specify a sequence of files
334 indexed by sequential numbers.
335
336 A sequence pattern may contain the string "%d" or "%0@var{N}d", which
337 specifies the position of the characters representing a sequential
338 number in each filename matched by the pattern. If the form
339 "%d0@var{N}d" is used, the string representing the number in each
340 filename is 0-padded and @var{N} is the total number of 0-padded
341 digits representing the number. The literal character '%' can be
342 specified in the pattern with the string "%%".
343
344 If the sequence pattern contains "%d" or "%0@var{N}d", the first filename of
345 the file list specified by the pattern must contain a number
346 inclusively contained between @var{start_number} and
347 @var{start_number}+@var{start_number_range}-1, and all the following
348 numbers must be sequential.
349
350 For example the pattern "img-%03d.bmp" will match a sequence of
351 filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ...,
352 @file{img-010.bmp}, etc.; the pattern "i%%m%%g-%d.jpg" will match a
353 sequence of filenames of the form @file{i%m%g-1.jpg},
354 @file{i%m%g-2.jpg}, ..., @file{i%m%g-10.jpg}, etc.
355
356 Note that the pattern must not necessarily contain "%d" or
357 "%0@var{N}d", for example to convert a single image file
358 @file{img.jpeg} you can employ the command:
359 @example
360 ffmpeg -i img.jpeg img.png
361 @end example
362
363 @item glob
364 Select a glob wildcard pattern type.
365
366 The pattern is interpreted like a @code{glob()} pattern. This is only
367 selectable if libavformat was compiled with globbing support.
368
369 @item glob_sequence @emph{(deprecated, will be removed)}
370 Select a mixed glob wildcard/sequence pattern.
371
372 If your version of libavformat was compiled with globbing support, and
373 the provided pattern contains at least one glob meta character among
374 @code{%*?[]@{@}} that is preceded by an unescaped "%", the pattern is
375 interpreted like a @code{glob()} pattern, otherwise it is interpreted
376 like a sequence pattern.
377
378 All glob special characters @code{%*?[]@{@}} must be prefixed
379 with "%". To escape a literal "%" you shall use "%%".
380
381 For example the pattern @code{foo-%*.jpeg} will match all the
382 filenames prefixed by "foo-" and terminating with ".jpeg", and
383 @code{foo-%?%?%?.jpeg} will match all the filenames prefixed with
384 "foo-", followed by a sequence of three characters, and terminating
385 with ".jpeg".
386
387 This pattern type is deprecated in favor of @var{glob} and
388 @var{sequence}.
389 @end table
390
391 Default value is @var{glob_sequence}.
392 @item pixel_format
393 Set the pixel format of the images to read. If not specified the pixel
394 format is guessed from the first image file in the sequence.
395 @item start_number
396 Set the index of the file matched by the image file pattern to start
397 to read from. Default value is 0.
398 @item start_number_range
399 Set the index interval range to check when looking for the first image
400 file in the sequence, starting from @var{start_number}. Default value
401 is 5.
402 @item ts_from_file
403 If set to 1, will set frame timestamp to modification time of image file. Note
404 that monotonity of timestamps is not provided: images go in the same order as
405 without this option. Default value is 0.
406 If set to 2, will set frame timestamp to the modification time of the image file in
407 nanosecond precision.
408 @item video_size
409 Set the video size of the images to read. If not specified the video
410 size is guessed from the first image file in the sequence.
411 @end table
412
413 @subsection Examples
414
415 @itemize
416 @item
417 Use @command{ffmpeg} for creating a video from the images in the file
418 sequence @file{img-001.jpeg}, @file{img-002.jpeg}, ..., assuming an
419 input frame rate of 10 frames per second:
420 @example
421 ffmpeg -framerate 10 -i 'img-%03d.jpeg' out.mkv
422 @end example
423
424 @item
425 As above, but start by reading from a file with index 100 in the sequence:
426 @example
427 ffmpeg -framerate 10 -start_number 100 -i 'img-%03d.jpeg' out.mkv
428 @end example
429
430 @item
431 Read images matching the "*.png" glob pattern , that is all the files
432 terminating with the ".png" suffix:
433 @example
434 ffmpeg -framerate 10 -pattern_type glob -i "*.png" out.mkv
435 @end example
436 @end itemize
437
438 @section libgme
439
440 The Game Music Emu library is a collection of video game music file emulators.
441
442 See @url{http://code.google.com/p/game-music-emu/} for more information.
443
444 Some files have multiple tracks. The demuxer will pick the first track by
445 default. The @option{track_index} option can be used to select a different
446 track. Track indexes start at 0. The demuxer exports the number of tracks as
447 @var{tracks} meta data entry.
448
449 For very large files, the @option{max_size} option may have to be adjusted.
450
451 @section libopenmpt
452
453 libopenmpt based module demuxer
454
455 See @url{https://lib.openmpt.org/libopenmpt/} for more information.
456
457 Some files have multiple subsongs (tracks) this can be set with the @option{subsong}
458 option.
459
460 It accepts the following options:
461
462 @table @option
463 @item subsong
464 Set the subsong index. This can be either  'all', 'auto', or the index of the
465 subsong. Subsong indexes start at 0. The default is 'auto'.
466
467 The default value is to let libopenmpt choose.
468
469 @item layout
470 Set the channel layout. Valid values are 1, 2, and 4 channel layouts.
471 The default value is STEREO.
472
473 @item sample_rate
474 Set the sample rate for libopenmpt to output.
475 Range is from 1000 to INT_MAX. The value default is 48000.
476 @end table
477
478 @section mov/mp4/3gp/QuickTime
479
480 QuickTime / MP4 demuxer.
481
482 This demuxer accepts the following options:
483 @table @option
484 @item enable_drefs
485 Enable loading of external tracks, disabled by default.
486 Enabling this can theoretically leak information in some use cases.
487
488 @item use_absolute_path
489 Allows loading of external tracks via absolute paths, disabled by default.
490 Enabling this poses a security risk. It should only be enabled if the source
491 is known to be non malicious.
492
493 @end table
494
495 @section mpegts
496
497 MPEG-2 transport stream demuxer.
498
499 This demuxer accepts the following options:
500 @table @option
501 @item resync_size
502 Set size limit for looking up a new synchronization. Default value is
503 65536.
504
505 @item fix_teletext_pts
506 Override teletext packet PTS and DTS values with the timestamps calculated
507 from the PCR of the first program which the teletext stream is part of and is
508 not discarded. Default value is 1, set this option to 0 if you want your
509 teletext packet PTS and DTS values untouched.
510
511 @item ts_packetsize
512 Output option carrying the raw packet size in bytes.
513 Show the detected raw packet size, cannot be set by the user.
514
515 @item scan_all_pmts
516 Scan and combine all PMTs. The value is an integer with value from -1
517 to 1 (-1 means automatic setting, 1 means enabled, 0 means
518 disabled). Default value is -1.
519 @end table
520
521 @section mpjpeg
522
523 MJPEG encapsulated in multi-part MIME demuxer.
524
525 This demuxer allows reading of MJPEG, where each frame is represented as a part of
526 multipart/x-mixed-replace stream.
527 @table @option
528
529 @item strict_mime_boundary
530 Default implementation applies a relaxed standard to multi-part MIME boundary detection,
531 to prevent regression with numerous existing endpoints not generating a proper MIME
532 MJPEG stream. Turning this option on by setting it to 1 will result in a stricter check
533 of the boundary value.
534 @end table
535
536 @section rawvideo
537
538 Raw video demuxer.
539
540 This demuxer allows one to read raw video data. Since there is no header
541 specifying the assumed video parameters, the user must specify them
542 in order to be able to decode the data correctly.
543
544 This demuxer accepts the following options:
545 @table @option
546
547 @item framerate
548 Set input video frame rate. Default value is 25.
549
550 @item pixel_format
551 Set the input video pixel format. Default value is @code{yuv420p}.
552
553 @item video_size
554 Set the input video size. This value must be specified explicitly.
555 @end table
556
557 For example to read a rawvideo file @file{input.raw} with
558 @command{ffplay}, assuming a pixel format of @code{rgb24}, a video
559 size of @code{320x240}, and a frame rate of 10 images per second, use
560 the command:
561 @example
562 ffplay -f rawvideo -pixel_format rgb24 -video_size 320x240 -framerate 10 input.raw
563 @end example
564
565 @section sbg
566
567 SBaGen script demuxer.
568
569 This demuxer reads the script language used by SBaGen
570 @url{http://uazu.net/sbagen/} to generate binaural beats sessions. A SBG
571 script looks like that:
572 @example
573 -SE
574 a: 300-2.5/3 440+4.5/0
575 b: 300-2.5/0 440+4.5/3
576 off: -
577 NOW      == a
578 +0:07:00 == b
579 +0:14:00 == a
580 +0:21:00 == b
581 +0:30:00    off
582 @end example
583
584 A SBG script can mix absolute and relative timestamps. If the script uses
585 either only absolute timestamps (including the script start time) or only
586 relative ones, then its layout is fixed, and the conversion is
587 straightforward. On the other hand, if the script mixes both kind of
588 timestamps, then the @var{NOW} reference for relative timestamps will be
589 taken from the current time of day at the time the script is read, and the
590 script layout will be frozen according to that reference. That means that if
591 the script is directly played, the actual times will match the absolute
592 timestamps up to the sound controller's clock accuracy, but if the user
593 somehow pauses the playback or seeks, all times will be shifted accordingly.
594
595 @section tedcaptions
596
597 JSON captions used for @url{http://www.ted.com/, TED Talks}.
598
599 TED does not provide links to the captions, but they can be guessed from the
600 page. The file @file{tools/bookmarklets.html} from the FFmpeg source tree
601 contains a bookmarklet to expose them.
602
603 This demuxer accepts the following option:
604 @table @option
605 @item start_time
606 Set the start time of the TED talk, in milliseconds. The default is 15000
607 (15s). It is used to sync the captions with the downloadable videos, because
608 they include a 15s intro.
609 @end table
610
611 Example: convert the captions to a format most players understand:
612 @example
613 ffmpeg -i http://www.ted.com/talks/subtitles/id/1/lang/en talk1-en.srt
614 @end example
615
616 @c man end DEMUXERS
617