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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{-formats} of the ff* tools will display the list of | |
17 | enabled demuxers. | |
18 | ||
19 | The description of some of the currently available demuxers follows. | |
20 | ||
21 | @section applehttp | |
22 | ||
23 | Apple HTTP Live Streaming demuxer. | |
24 | ||
25 | This demuxer presents all AVStreams from all variant streams. | |
26 | The id field is set to the bitrate variant index number. By setting | |
27 | the discard flags on AVStreams (by pressing 'a' or 'v' in ffplay), | |
28 | the caller can decide which variant streams to actually receive. | |
29 | The total bitrate of the variant that the stream belongs to is | |
30 | available in a metadata key named "variant_bitrate". | |
31 | ||
32 | @section asf | |
33 | ||
34 | Advanced Systems Format demuxer. | |
35 | ||
36 | This demuxer is used to demux ASF files and MMS network streams. | |
37 | ||
38 | @table @option | |
39 | @item -no_resync_search @var{bool} | |
40 | Do not try to resynchronize by looking for a certain optional start code. | |
41 | @end table | |
42 | ||
43 | @anchor{concat} | |
44 | @section concat | |
45 | ||
46 | Virtual concatenation script demuxer. | |
47 | ||
48 | This demuxer reads a list of files and other directives from a text file and | |
49 | demuxes them one after the other, as if all their packet had been muxed | |
50 | together. | |
51 | ||
52 | The timestamps in the files are adjusted so that the first file starts at 0 | |
53 | and each next file starts where the previous one finishes. Note that it is | |
54 | done globally and may cause gaps if all streams do not have exactly the same | |
55 | length. | |
56 | ||
57 | All files must have the same streams (same codecs, same time base, etc.). | |
58 | ||
59 | The duration of each file is used to adjust the timestamps of the next file: | |
60 | if the duration is incorrect (because it was computed using the bit-rate or | |
61 | because the file is truncated, for example), it can cause artifacts. The | |
62 | @code{duration} directive can be used to override the duration stored in | |
63 | each file. | |
64 | ||
65 | @subsection Syntax | |
66 | ||
67 | The script is a text file in extended-ASCII, with one directive per line. | |
68 | Empty lines, leading spaces and lines starting with '#' are ignored. The | |
69 | following directive is recognized: | |
70 | ||
71 | @table @option | |
72 | ||
73 | @item @code{file @var{path}} | |
74 | Path to a file to read; special characters and spaces must be escaped with | |
75 | backslash or single quotes. | |
76 | ||
77 | All subsequent file-related directives apply to that file. | |
78 | ||
79 | @item @code{ffconcat version 1.0} | |
80 | Identify the script type and version. It also sets the @option{safe} option | |
81 | to 1 if it was to its default -1. | |
82 | ||
83 | To make FFmpeg recognize the format automatically, this directive must | |
84 | appears exactly as is (no extra space or byte-order-mark) on the very first | |
85 | line of the script. | |
86 | ||
87 | @item @code{duration @var{dur}} | |
88 | Duration of the file. This information can be specified from the file; | |
89 | specifying it here may be more efficient or help if the information from the | |
90 | file is not available or accurate. | |
91 | ||
92 | If the duration is set for all files, then it is possible to seek in the | |
93 | whole concatenated video. | |
94 | ||
95 | @item @code{stream} | |
96 | Introduce a stream in the virtual file. | |
97 | All subsequent stream-related directives apply to the last introduced | |
98 | stream. | |
99 | Some streams properties must be set in order to allow identifying the | |
100 | matching streams in the subfiles. | |
101 | If no streams are defined in the script, the streams from the first file are | |
102 | copied. | |
103 | ||
104 | @item @code{exact_stream_id @var{id}} | |
105 | Set the id of the stream. | |
106 | If this directive is given, the string with the corresponding id in the | |
107 | subfiles will be used. | |
108 | This is especially useful for MPEG-PS (VOB) files, where the order of the | |
109 | streams is not reliable. | |
110 | ||
111 | @end table | |
112 | ||
113 | @subsection Options | |
114 | ||
115 | This demuxer accepts the following option: | |
116 | ||
117 | @table @option | |
118 | ||
119 | @item safe | |
120 | If set to 1, reject unsafe file paths. A file path is considered safe if it | |
121 | does not contain a protocol specification and is relative and all components | |
122 | only contain characters from the portable character set (letters, digits, | |
123 | period, underscore and hyphen) and have no period at the beginning of a | |
124 | component. | |
125 | ||
126 | If set to 0, any file name is accepted. | |
127 | ||
128 | The default is -1, it is equivalent to 1 if the format was automatically | |
129 | probed and 0 otherwise. | |
130 | ||
131 | @item auto_convert | |
132 | If set to 1, try to perform automatic conversions on packet data to make the | |
133 | streams concatenable. | |
134 | ||
135 | Currently, the only conversion is adding the h264_mp4toannexb bitstream | |
136 | filter to H.264 streams in MP4 format. This is necessary in particular if | |
137 | there are resolution changes. | |
138 | ||
139 | @end table | |
140 | ||
141 | @section flv | |
142 | ||
143 | Adobe Flash Video Format demuxer. | |
144 | ||
145 | This demuxer is used to demux FLV files and RTMP network streams. | |
146 | ||
147 | @table @option | |
148 | @item -flv_metadata @var{bool} | |
149 | Allocate the streams according to the onMetaData array content. | |
150 | @end table | |
151 | ||
152 | @section libgme | |
153 | ||
154 | The Game Music Emu library is a collection of video game music file emulators. | |
155 | ||
156 | See @url{http://code.google.com/p/game-music-emu/} for more information. | |
157 | ||
158 | Some files have multiple tracks. The demuxer will pick the first track by | |
159 | default. The @option{track_index} option can be used to select a different | |
160 | track. Track indexes start at 0. The demuxer exports the number of tracks as | |
161 | @var{tracks} meta data entry. | |
162 | ||
163 | For very large files, the @option{max_size} option may have to be adjusted. | |
164 | ||
165 | @section libquvi | |
166 | ||
167 | Play media from Internet services using the quvi project. | |
168 | ||
169 | The demuxer accepts a @option{format} option to request a specific quality. It | |
170 | is by default set to @var{best}. | |
171 | ||
172 | See @url{http://quvi.sourceforge.net/} for more information. | |
173 | ||
174 | FFmpeg needs to be built with @code{--enable-libquvi} for this demuxer to be | |
175 | enabled. | |
176 | ||
177 | @section gif | |
178 | ||
179 | Animated GIF demuxer. | |
180 | ||
181 | It accepts the following options: | |
182 | ||
183 | @table @option | |
184 | @item min_delay | |
185 | Set the minimum valid delay between frames in hundredths of seconds. | |
186 | Range is 0 to 6000. Default value is 2. | |
187 | ||
188 | @item default_delay | |
189 | Set the default delay between frames in hundredths of seconds. | |
190 | Range is 0 to 6000. Default value is 10. | |
191 | ||
192 | @item ignore_loop | |
193 | GIF files can contain information to loop a certain number of times (or | |
194 | infinitely). If @option{ignore_loop} is set to 1, then the loop setting | |
195 | from the input will be ignored and looping will not occur. If set to 0, | |
196 | then looping will occur and will cycle the number of times according to | |
197 | the GIF. Default value is 1. | |
198 | @end table | |
199 | ||
200 | For example, with the overlay filter, place an infinitely looping GIF | |
201 | over another video: | |
202 | @example | |
203 | ffmpeg -i input.mp4 -ignore_loop 0 -i input.gif -filter_complex overlay=shortest=1 out.mkv | |
204 | @end example | |
205 | ||
206 | Note that in the above example the shortest option for overlay filter is | |
207 | used to end the output video at the length of the shortest input file, | |
208 | which in this case is @file{input.mp4} as the GIF in this example loops | |
209 | infinitely. | |
210 | ||
211 | @section image2 | |
212 | ||
213 | Image file demuxer. | |
214 | ||
215 | This demuxer reads from a list of image files specified by a pattern. | |
216 | The syntax and meaning of the pattern is specified by the | |
217 | option @var{pattern_type}. | |
218 | ||
219 | The pattern may contain a suffix which is used to automatically | |
220 | determine the format of the images contained in the files. | |
221 | ||
222 | The size, the pixel format, and the format of each image must be the | |
223 | same for all the files in the sequence. | |
224 | ||
225 | This demuxer accepts the following options: | |
226 | @table @option | |
227 | @item framerate | |
228 | Set the frame rate for the video stream. It defaults to 25. | |
229 | @item loop | |
230 | If set to 1, loop over the input. Default value is 0. | |
231 | @item pattern_type | |
232 | Select the pattern type used to interpret the provided filename. | |
233 | ||
234 | @var{pattern_type} accepts one of the following values. | |
235 | @table @option | |
236 | @item sequence | |
237 | Select a sequence pattern type, used to specify a sequence of files | |
238 | indexed by sequential numbers. | |
239 | ||
240 | A sequence pattern may contain the string "%d" or "%0@var{N}d", which | |
241 | specifies the position of the characters representing a sequential | |
242 | number in each filename matched by the pattern. If the form | |
243 | "%d0@var{N}d" is used, the string representing the number in each | |
244 | filename is 0-padded and @var{N} is the total number of 0-padded | |
245 | digits representing the number. The literal character '%' can be | |
246 | specified in the pattern with the string "%%". | |
247 | ||
248 | If the sequence pattern contains "%d" or "%0@var{N}d", the first filename of | |
249 | the file list specified by the pattern must contain a number | |
250 | inclusively contained between @var{start_number} and | |
251 | @var{start_number}+@var{start_number_range}-1, and all the following | |
252 | numbers must be sequential. | |
253 | ||
254 | For example the pattern "img-%03d.bmp" will match a sequence of | |
255 | filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ..., | |
256 | @file{img-010.bmp}, etc.; the pattern "i%%m%%g-%d.jpg" will match a | |
257 | sequence of filenames of the form @file{i%m%g-1.jpg}, | |
258 | @file{i%m%g-2.jpg}, ..., @file{i%m%g-10.jpg}, etc. | |
259 | ||
260 | Note that the pattern must not necessarily contain "%d" or | |
261 | "%0@var{N}d", for example to convert a single image file | |
262 | @file{img.jpeg} you can employ the command: | |
263 | @example | |
264 | ffmpeg -i img.jpeg img.png | |
265 | @end example | |
266 | ||
267 | @item glob | |
268 | Select a glob wildcard pattern type. | |
269 | ||
270 | The pattern is interpreted like a @code{glob()} pattern. This is only | |
271 | selectable if libavformat was compiled with globbing support. | |
272 | ||
273 | @item glob_sequence @emph{(deprecated, will be removed)} | |
274 | Select a mixed glob wildcard/sequence pattern. | |
275 | ||
276 | If your version of libavformat was compiled with globbing support, and | |
277 | the provided pattern contains at least one glob meta character among | |
278 | @code{%*?[]@{@}} that is preceded by an unescaped "%", the pattern is | |
279 | interpreted like a @code{glob()} pattern, otherwise it is interpreted | |
280 | like a sequence pattern. | |
281 | ||
282 | All glob special characters @code{%*?[]@{@}} must be prefixed | |
283 | with "%". To escape a literal "%" you shall use "%%". | |
284 | ||
285 | For example the pattern @code{foo-%*.jpeg} will match all the | |
286 | filenames prefixed by "foo-" and terminating with ".jpeg", and | |
287 | @code{foo-%?%?%?.jpeg} will match all the filenames prefixed with | |
288 | "foo-", followed by a sequence of three characters, and terminating | |
289 | with ".jpeg". | |
290 | ||
291 | This pattern type is deprecated in favor of @var{glob} and | |
292 | @var{sequence}. | |
293 | @end table | |
294 | ||
295 | Default value is @var{glob_sequence}. | |
296 | @item pixel_format | |
297 | Set the pixel format of the images to read. If not specified the pixel | |
298 | format is guessed from the first image file in the sequence. | |
299 | @item start_number | |
300 | Set the index of the file matched by the image file pattern to start | |
301 | to read from. Default value is 0. | |
302 | @item start_number_range | |
303 | Set the index interval range to check when looking for the first image | |
304 | file in the sequence, starting from @var{start_number}. Default value | |
305 | is 5. | |
306 | @item ts_from_file | |
307 | If set to 1, will set frame timestamp to modification time of image file. Note | |
308 | that monotonity of timestamps is not provided: images go in the same order as | |
309 | without this option. Default value is 0. | |
310 | If set to 2, will set frame timestamp to the modification time of the image file in | |
311 | nanosecond precision. | |
312 | @item video_size | |
313 | Set the video size of the images to read. If not specified the video | |
314 | size is guessed from the first image file in the sequence. | |
315 | @end table | |
316 | ||
317 | @subsection Examples | |
318 | ||
319 | @itemize | |
320 | @item | |
321 | Use @command{ffmpeg} for creating a video from the images in the file | |
322 | sequence @file{img-001.jpeg}, @file{img-002.jpeg}, ..., assuming an | |
323 | input frame rate of 10 frames per second: | |
324 | @example | |
325 | ffmpeg -framerate 10 -i 'img-%03d.jpeg' out.mkv | |
326 | @end example | |
327 | ||
328 | @item | |
329 | As above, but start by reading from a file with index 100 in the sequence: | |
330 | @example | |
331 | ffmpeg -framerate 10 -start_number 100 -i 'img-%03d.jpeg' out.mkv | |
332 | @end example | |
333 | ||
334 | @item | |
335 | Read images matching the "*.png" glob pattern , that is all the files | |
336 | terminating with the ".png" suffix: | |
337 | @example | |
338 | ffmpeg -framerate 10 -pattern_type glob -i "*.png" out.mkv | |
339 | @end example | |
340 | @end itemize | |
341 | ||
342 | @section mpegts | |
343 | ||
344 | MPEG-2 transport stream demuxer. | |
345 | ||
346 | @table @option | |
347 | ||
348 | @item fix_teletext_pts | |
349 | Overrides teletext packet PTS and DTS values with the timestamps calculated | |
350 | from the PCR of the first program which the teletext stream is part of and is | |
351 | not discarded. Default value is 1, set this option to 0 if you want your | |
352 | teletext packet PTS and DTS values untouched. | |
353 | @end table | |
354 | ||
355 | @section rawvideo | |
356 | ||
357 | Raw video demuxer. | |
358 | ||
359 | This demuxer allows one to read raw video data. Since there is no header | |
360 | specifying the assumed video parameters, the user must specify them | |
361 | in order to be able to decode the data correctly. | |
362 | ||
363 | This demuxer accepts the following options: | |
364 | @table @option | |
365 | ||
366 | @item framerate | |
367 | Set input video frame rate. Default value is 25. | |
368 | ||
369 | @item pixel_format | |
370 | Set the input video pixel format. Default value is @code{yuv420p}. | |
371 | ||
372 | @item video_size | |
373 | Set the input video size. This value must be specified explicitly. | |
374 | @end table | |
375 | ||
376 | For example to read a rawvideo file @file{input.raw} with | |
377 | @command{ffplay}, assuming a pixel format of @code{rgb24}, a video | |
378 | size of @code{320x240}, and a frame rate of 10 images per second, use | |
379 | the command: | |
380 | @example | |
381 | ffplay -f rawvideo -pixel_format rgb24 -video_size 320x240 -framerate 10 input.raw | |
382 | @end example | |
383 | ||
384 | @section sbg | |
385 | ||
386 | SBaGen script demuxer. | |
387 | ||
388 | This demuxer reads the script language used by SBaGen | |
389 | @url{http://uazu.net/sbagen/} to generate binaural beats sessions. A SBG | |
390 | script looks like that: | |
391 | @example | |
392 | -SE | |
393 | a: 300-2.5/3 440+4.5/0 | |
394 | b: 300-2.5/0 440+4.5/3 | |
395 | off: - | |
396 | NOW == a | |
397 | +0:07:00 == b | |
398 | +0:14:00 == a | |
399 | +0:21:00 == b | |
400 | +0:30:00 off | |
401 | @end example | |
402 | ||
403 | A SBG script can mix absolute and relative timestamps. If the script uses | |
404 | either only absolute timestamps (including the script start time) or only | |
405 | relative ones, then its layout is fixed, and the conversion is | |
406 | straightforward. On the other hand, if the script mixes both kind of | |
407 | timestamps, then the @var{NOW} reference for relative timestamps will be | |
408 | taken from the current time of day at the time the script is read, and the | |
409 | script layout will be frozen according to that reference. That means that if | |
410 | the script is directly played, the actual times will match the absolute | |
411 | timestamps up to the sound controller's clock accuracy, but if the user | |
412 | somehow pauses the playback or seeks, all times will be shifted accordingly. | |
413 | ||
414 | @section tedcaptions | |
415 | ||
416 | JSON captions used for @url{http://www.ted.com/, TED Talks}. | |
417 | ||
418 | TED does not provide links to the captions, but they can be guessed from the | |
419 | page. The file @file{tools/bookmarklets.html} from the FFmpeg source tree | |
420 | contains a bookmarklet to expose them. | |
421 | ||
422 | This demuxer accepts the following option: | |
423 | @table @option | |
424 | @item start_time | |
425 | Set the start time of the TED talk, in milliseconds. The default is 15000 | |
426 | (15s). It is used to sync the captions with the downloadable videos, because | |
427 | they include a 15s intro. | |
428 | @end table | |
429 | ||
430 | Example: convert the captions to a format most players understand: | |
431 | @example | |
432 | ffmpeg -i http://www.ted.com/talks/subtitles/id/1/lang/en talk1-en.srt | |
433 | @end example | |
434 | ||
435 | @c man end DEMUXERS |