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1 | @chapter Muxers |
2 | @c man begin MUXERS | |
3 | ||
4 | Muxers are configured elements in FFmpeg which allow writing | |
5 | multimedia streams to a particular type of file. | |
6 | ||
7 | When you configure your FFmpeg build, all the supported muxers | |
8 | are enabled by default. You can list all available muxers using the | |
9 | configure option @code{--list-muxers}. | |
10 | ||
11 | You can disable all the muxers with the configure option | |
12 | @code{--disable-muxers} and selectively enable / disable single muxers | |
13 | with the options @code{--enable-muxer=@var{MUXER}} / | |
14 | @code{--disable-muxer=@var{MUXER}}. | |
15 | ||
16 | The option @code{-formats} of the ff* tools will display the list of | |
17 | enabled muxers. | |
18 | ||
19 | A description of some of the currently available muxers follows. | |
20 | ||
21 | @anchor{aiff} | |
22 | @section aiff | |
23 | ||
24 | Audio Interchange File Format muxer. | |
25 | ||
26 | @subsection Options | |
27 | ||
28 | It accepts the following options: | |
29 | ||
30 | @table @option | |
31 | @item write_id3v2 | |
32 | Enable ID3v2 tags writing when set to 1. Default is 0 (disabled). | |
33 | ||
34 | @item id3v2_version | |
35 | Select ID3v2 version to write. Currently only version 3 and 4 (aka. | |
36 | ID3v2.3 and ID3v2.4) are supported. The default is version 4. | |
37 | ||
38 | @end table | |
39 | ||
40 | @anchor{crc} | |
41 | @section crc | |
42 | ||
43 | CRC (Cyclic Redundancy Check) testing format. | |
44 | ||
45 | This muxer computes and prints the Adler-32 CRC of all the input audio | |
46 | and video frames. By default audio frames are converted to signed | |
47 | 16-bit raw audio and video frames to raw video before computing the | |
48 | CRC. | |
49 | ||
50 | The output of the muxer consists of a single line of the form: | |
51 | CRC=0x@var{CRC}, where @var{CRC} is a hexadecimal number 0-padded to | |
52 | 8 digits containing the CRC for all the decoded input frames. | |
53 | ||
54 | See also the @ref{framecrc} muxer. | |
55 | ||
56 | @subsection Examples | |
57 | ||
58 | For example to compute the CRC of the input, and store it in the file | |
59 | @file{out.crc}: | |
60 | @example | |
61 | ffmpeg -i INPUT -f crc out.crc | |
62 | @end example | |
63 | ||
64 | You can print the CRC to stdout with the command: | |
65 | @example | |
66 | ffmpeg -i INPUT -f crc - | |
67 | @end example | |
68 | ||
69 | You can select the output format of each frame with @command{ffmpeg} by | |
70 | specifying the audio and video codec and format. For example to | |
71 | compute the CRC of the input audio converted to PCM unsigned 8-bit | |
72 | and the input video converted to MPEG-2 video, use the command: | |
73 | @example | |
74 | ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc - | |
75 | @end example | |
76 | ||
77 | @anchor{framecrc} | |
78 | @section framecrc | |
79 | ||
80 | Per-packet CRC (Cyclic Redundancy Check) testing format. | |
81 | ||
82 | This muxer computes and prints the Adler-32 CRC for each audio | |
83 | and video packet. By default audio frames are converted to signed | |
84 | 16-bit raw audio and video frames to raw video before computing the | |
85 | CRC. | |
86 | ||
87 | The output of the muxer consists of a line for each audio and video | |
88 | packet of the form: | |
89 | @example | |
90 | @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, 0x@var{CRC} | |
91 | @end example | |
92 | ||
93 | @var{CRC} is a hexadecimal number 0-padded to 8 digits containing the | |
94 | CRC of the packet. | |
95 | ||
96 | @subsection Examples | |
97 | ||
98 | For example to compute the CRC of the audio and video frames in | |
99 | @file{INPUT}, converted to raw audio and video packets, and store it | |
100 | in the file @file{out.crc}: | |
101 | @example | |
102 | ffmpeg -i INPUT -f framecrc out.crc | |
103 | @end example | |
104 | ||
105 | To print the information to stdout, use the command: | |
106 | @example | |
107 | ffmpeg -i INPUT -f framecrc - | |
108 | @end example | |
109 | ||
110 | With @command{ffmpeg}, you can select the output format to which the | |
111 | audio and video frames are encoded before computing the CRC for each | |
112 | packet by specifying the audio and video codec. For example, to | |
113 | compute the CRC of each decoded input audio frame converted to PCM | |
114 | unsigned 8-bit and of each decoded input video frame converted to | |
115 | MPEG-2 video, use the command: | |
116 | @example | |
117 | ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc - | |
118 | @end example | |
119 | ||
120 | See also the @ref{crc} muxer. | |
121 | ||
122 | @anchor{framemd5} | |
123 | @section framemd5 | |
124 | ||
125 | Per-packet MD5 testing format. | |
126 | ||
127 | This muxer computes and prints the MD5 hash for each audio | |
128 | and video packet. By default audio frames are converted to signed | |
129 | 16-bit raw audio and video frames to raw video before computing the | |
130 | hash. | |
131 | ||
132 | The output of the muxer consists of a line for each audio and video | |
133 | packet of the form: | |
134 | @example | |
135 | @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, @var{MD5} | |
136 | @end example | |
137 | ||
138 | @var{MD5} is a hexadecimal number representing the computed MD5 hash | |
139 | for the packet. | |
140 | ||
141 | @subsection Examples | |
142 | ||
143 | For example to compute the MD5 of the audio and video frames in | |
144 | @file{INPUT}, converted to raw audio and video packets, and store it | |
145 | in the file @file{out.md5}: | |
146 | @example | |
147 | ffmpeg -i INPUT -f framemd5 out.md5 | |
148 | @end example | |
149 | ||
150 | To print the information to stdout, use the command: | |
151 | @example | |
152 | ffmpeg -i INPUT -f framemd5 - | |
153 | @end example | |
154 | ||
155 | See also the @ref{md5} muxer. | |
156 | ||
157 | @anchor{gif} | |
158 | @section gif | |
159 | ||
160 | Animated GIF muxer. | |
161 | ||
162 | It accepts the following options: | |
163 | ||
164 | @table @option | |
165 | @item loop | |
166 | Set the number of times to loop the output. Use @code{-1} for no loop, @code{0} | |
167 | for looping indefinitely (default). | |
168 | ||
169 | @item final_delay | |
170 | Force the delay (expressed in centiseconds) after the last frame. Each frame | |
171 | ends with a delay until the next frame. The default is @code{-1}, which is a | |
172 | special value to tell the muxer to re-use the previous delay. In case of a | |
173 | loop, you might want to customize this value to mark a pause for instance. | |
174 | @end table | |
175 | ||
176 | For example, to encode a gif looping 10 times, with a 5 seconds delay between | |
177 | the loops: | |
178 | @example | |
179 | ffmpeg -i INPUT -loop 10 -final_delay 500 out.gif | |
180 | @end example | |
181 | ||
182 | Note 1: if you wish to extract the frames in separate GIF files, you need to | |
183 | force the @ref{image2} muxer: | |
184 | @example | |
185 | ffmpeg -i INPUT -c:v gif -f image2 "out%d.gif" | |
186 | @end example | |
187 | ||
188 | Note 2: the GIF format has a very small time base: the delay between two frames | |
189 | can not be smaller than one centi second. | |
190 | ||
191 | @anchor{hls} | |
192 | @section hls | |
193 | ||
194 | Apple HTTP Live Streaming muxer that segments MPEG-TS according to | |
195 | the HTTP Live Streaming (HLS) specification. | |
196 | ||
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197 | It creates a playlist file, and one or more segment files. The output filename |
198 | specifies the playlist filename. | |
199 | ||
200 | By default, the muxer creates a file for each segment produced. These files | |
201 | have the same name as the playlist, followed by a sequential number and a | |
202 | .ts extension. | |
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203 | |
204 | For example, to convert an input file with @command{ffmpeg}: | |
205 | @example | |
206 | ffmpeg -i in.nut out.m3u8 | |
207 | @end example | |
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208 | This example will produce the playlist, @file{out.m3u8}, and segment files: |
209 | @file{out0.ts}, @file{out1.ts}, @file{out2.ts}, etc. | |
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210 | |
211 | See also the @ref{segment} muxer, which provides a more generic and | |
212 | flexible implementation of a segmenter, and can be used to perform HLS | |
213 | segmentation. | |
214 | ||
215 | @subsection Options | |
216 | ||
217 | This muxer supports the following options: | |
218 | ||
219 | @table @option | |
220 | @item hls_time @var{seconds} | |
221 | Set the segment length in seconds. Default value is 2. | |
222 | ||
223 | @item hls_list_size @var{size} | |
224 | Set the maximum number of playlist entries. If set to 0 the list file | |
225 | will contain all the segments. Default value is 5. | |
226 | ||
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227 | @item hls_ts_options @var{options_list} |
228 | Set output format options using a :-separated list of key=value | |
229 | parameters. Values containing @code{:} special characters must be | |
230 | escaped. | |
231 | ||
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232 | @item hls_wrap @var{wrap} |
233 | Set the number after which the segment filename number (the number | |
234 | specified in each segment file) wraps. If set to 0 the number will be | |
235 | never wrapped. Default value is 0. | |
236 | ||
237 | This option is useful to avoid to fill the disk with many segment | |
238 | files, and limits the maximum number of segment files written to disk | |
239 | to @var{wrap}. | |
240 | ||
241 | @item start_number @var{number} | |
242 | Start the playlist sequence number from @var{number}. Default value is | |
243 | 0. | |
244 | ||
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245 | @item hls_allow_cache @var{allowcache} |
246 | Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments. | |
247 | ||
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248 | @item hls_base_url @var{baseurl} |
249 | Append @var{baseurl} to every entry in the playlist. | |
250 | Useful to generate playlists with absolute paths. | |
251 | ||
252 | Note that the playlist sequence number must be unique for each segment | |
253 | and it is not to be confused with the segment filename sequence number | |
254 | which can be cyclic, for example if the @option{wrap} option is | |
255 | specified. | |
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256 | |
257 | @item hls_flags single_file | |
258 | If this flag is set, the muxer will store all segments in a single MPEG-TS | |
259 | file, and will use byte ranges in the playlist. HLS playlists generated with | |
260 | this way will have the version number 4. | |
261 | For example: | |
262 | @example | |
263 | ffmpeg -i in.nut -hls_flags single_file out.m3u8 | |
264 | @end example | |
265 | Will produce the playlist, @file{out.m3u8}, and a single segment file, | |
266 | @file{out.ts}. | |
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267 | @end table |
268 | ||
269 | @anchor{ico} | |
270 | @section ico | |
271 | ||
272 | ICO file muxer. | |
273 | ||
274 | Microsoft's icon file format (ICO) has some strict limitations that should be noted: | |
275 | ||
276 | @itemize | |
277 | @item | |
278 | Size cannot exceed 256 pixels in any dimension | |
279 | ||
280 | @item | |
281 | Only BMP and PNG images can be stored | |
282 | ||
283 | @item | |
284 | If a BMP image is used, it must be one of the following pixel formats: | |
285 | @example | |
286 | BMP Bit Depth FFmpeg Pixel Format | |
287 | 1bit pal8 | |
288 | 4bit pal8 | |
289 | 8bit pal8 | |
290 | 16bit rgb555le | |
291 | 24bit bgr24 | |
292 | 32bit bgra | |
293 | @end example | |
294 | ||
295 | @item | |
296 | If a BMP image is used, it must use the BITMAPINFOHEADER DIB header | |
297 | ||
298 | @item | |
299 | If a PNG image is used, it must use the rgba pixel format | |
300 | @end itemize | |
301 | ||
302 | @anchor{image2} | |
303 | @section image2 | |
304 | ||
305 | Image file muxer. | |
306 | ||
307 | The image file muxer writes video frames to image files. | |
308 | ||
309 | The output filenames are specified by a pattern, which can be used to | |
310 | produce sequentially numbered series of files. | |
311 | The pattern may contain the string "%d" or "%0@var{N}d", this string | |
312 | specifies the position of the characters representing a numbering in | |
313 | the filenames. If the form "%0@var{N}d" is used, the string | |
314 | representing the number in each filename is 0-padded to @var{N} | |
315 | digits. The literal character '%' can be specified in the pattern with | |
316 | the string "%%". | |
317 | ||
318 | If the pattern contains "%d" or "%0@var{N}d", the first filename of | |
319 | the file list specified will contain the number 1, all the following | |
320 | numbers will be sequential. | |
321 | ||
322 | The pattern may contain a suffix which is used to automatically | |
323 | determine the format of the image files to write. | |
324 | ||
325 | For example the pattern "img-%03d.bmp" will specify a sequence of | |
326 | filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ..., | |
327 | @file{img-010.bmp}, etc. | |
328 | The pattern "img%%-%d.jpg" will specify a sequence of filenames of the | |
329 | form @file{img%-1.jpg}, @file{img%-2.jpg}, ..., @file{img%-10.jpg}, | |
330 | etc. | |
331 | ||
332 | @subsection Examples | |
333 | ||
334 | The following example shows how to use @command{ffmpeg} for creating a | |
335 | sequence of files @file{img-001.jpeg}, @file{img-002.jpeg}, ..., | |
336 | taking one image every second from the input video: | |
337 | @example | |
338 | ffmpeg -i in.avi -vsync 1 -r 1 -f image2 'img-%03d.jpeg' | |
339 | @end example | |
340 | ||
341 | Note that with @command{ffmpeg}, if the format is not specified with the | |
342 | @code{-f} option and the output filename specifies an image file | |
343 | format, the image2 muxer is automatically selected, so the previous | |
344 | command can be written as: | |
345 | @example | |
346 | ffmpeg -i in.avi -vsync 1 -r 1 'img-%03d.jpeg' | |
347 | @end example | |
348 | ||
349 | Note also that the pattern must not necessarily contain "%d" or | |
350 | "%0@var{N}d", for example to create a single image file | |
351 | @file{img.jpeg} from the input video you can employ the command: | |
352 | @example | |
353 | ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg | |
354 | @end example | |
355 | ||
356 | The @option{strftime} option allows you to expand the filename with | |
357 | date and time information. Check the documentation of | |
358 | the @code{strftime()} function for the syntax. | |
359 | ||
360 | For example to generate image files from the @code{strftime()} | |
361 | "%Y-%m-%d_%H-%M-%S" pattern, the following @command{ffmpeg} command | |
362 | can be used: | |
363 | @example | |
364 | ffmpeg -f v4l2 -r 1 -i /dev/video0 -f image2 -strftime 1 "%Y-%m-%d_%H-%M-%S.jpg" | |
365 | @end example | |
366 | ||
367 | @subsection Options | |
368 | ||
369 | @table @option | |
370 | @item start_number | |
371 | Start the sequence from the specified number. Default value is 1. Must | |
372 | be a non-negative number. | |
373 | ||
374 | @item update | |
375 | If set to 1, the filename will always be interpreted as just a | |
376 | filename, not a pattern, and the corresponding file will be continuously | |
377 | overwritten with new images. Default value is 0. | |
378 | ||
379 | @item strftime | |
380 | If set to 1, expand the filename with date and time information from | |
381 | @code{strftime()}. Default value is 0. | |
382 | @end table | |
383 | ||
384 | The image muxer supports the .Y.U.V image file format. This format is | |
385 | special in that that each image frame consists of three files, for | |
386 | each of the YUV420P components. To read or write this image file format, | |
387 | specify the name of the '.Y' file. The muxer will automatically open the | |
388 | '.U' and '.V' files as required. | |
389 | ||
390 | @section matroska | |
391 | ||
392 | Matroska container muxer. | |
393 | ||
394 | This muxer implements the matroska and webm container specs. | |
395 | ||
396 | @subsection Metadata | |
397 | ||
398 | The recognized metadata settings in this muxer are: | |
399 | ||
400 | @table @option | |
401 | @item title | |
402 | Set title name provided to a single track. | |
403 | ||
404 | @item language | |
405 | Specify the language of the track in the Matroska languages form. | |
406 | ||
407 | The language can be either the 3 letters bibliographic ISO-639-2 (ISO | |
408 | 639-2/B) form (like "fre" for French), or a language code mixed with a | |
409 | country code for specialities in languages (like "fre-ca" for Canadian | |
410 | French). | |
411 | ||
412 | @item stereo_mode | |
413 | Set stereo 3D video layout of two views in a single video track. | |
414 | ||
415 | The following values are recognized: | |
416 | @table @samp | |
417 | @item mono | |
418 | video is not stereo | |
419 | @item left_right | |
420 | Both views are arranged side by side, Left-eye view is on the left | |
421 | @item bottom_top | |
422 | Both views are arranged in top-bottom orientation, Left-eye view is at bottom | |
423 | @item top_bottom | |
424 | Both views are arranged in top-bottom orientation, Left-eye view is on top | |
425 | @item checkerboard_rl | |
426 | Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first | |
427 | @item checkerboard_lr | |
428 | Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first | |
429 | @item row_interleaved_rl | |
430 | Each view is constituted by a row based interleaving, Right-eye view is first row | |
431 | @item row_interleaved_lr | |
432 | Each view is constituted by a row based interleaving, Left-eye view is first row | |
433 | @item col_interleaved_rl | |
434 | Both views are arranged in a column based interleaving manner, Right-eye view is first column | |
435 | @item col_interleaved_lr | |
436 | Both views are arranged in a column based interleaving manner, Left-eye view is first column | |
437 | @item anaglyph_cyan_red | |
438 | All frames are in anaglyph format viewable through red-cyan filters | |
439 | @item right_left | |
440 | Both views are arranged side by side, Right-eye view is on the left | |
441 | @item anaglyph_green_magenta | |
442 | All frames are in anaglyph format viewable through green-magenta filters | |
443 | @item block_lr | |
444 | Both eyes laced in one Block, Left-eye view is first | |
445 | @item block_rl | |
446 | Both eyes laced in one Block, Right-eye view is first | |
447 | @end table | |
448 | @end table | |
449 | ||
450 | For example a 3D WebM clip can be created using the following command line: | |
451 | @example | |
452 | ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm | |
453 | @end example | |
454 | ||
455 | @subsection Options | |
456 | ||
457 | This muxer supports the following options: | |
458 | ||
459 | @table @option | |
460 | @item reserve_index_space | |
461 | By default, this muxer writes the index for seeking (called cues in Matroska | |
462 | terms) at the end of the file, because it cannot know in advance how much space | |
463 | to leave for the index at the beginning of the file. However for some use cases | |
464 | -- e.g. streaming where seeking is possible but slow -- it is useful to put the | |
465 | index at the beginning of the file. | |
466 | ||
467 | If this option is set to a non-zero value, the muxer will reserve a given amount | |
468 | of space in the file header and then try to write the cues there when the muxing | |
469 | finishes. If the available space does not suffice, muxing will fail. A safe size | |
470 | for most use cases should be about 50kB per hour of video. | |
471 | ||
472 | Note that cues are only written if the output is seekable and this option will | |
473 | have no effect if it is not. | |
474 | @end table | |
475 | ||
476 | @anchor{md5} | |
477 | @section md5 | |
478 | ||
479 | MD5 testing format. | |
480 | ||
481 | This muxer computes and prints the MD5 hash of all the input audio | |
482 | and video frames. By default audio frames are converted to signed | |
483 | 16-bit raw audio and video frames to raw video before computing the | |
484 | hash. | |
485 | ||
486 | The output of the muxer consists of a single line of the form: | |
487 | MD5=@var{MD5}, where @var{MD5} is a hexadecimal number representing | |
488 | the computed MD5 hash. | |
489 | ||
490 | For example to compute the MD5 hash of the input converted to raw | |
491 | audio and video, and store it in the file @file{out.md5}: | |
492 | @example | |
493 | ffmpeg -i INPUT -f md5 out.md5 | |
494 | @end example | |
495 | ||
496 | You can print the MD5 to stdout with the command: | |
497 | @example | |
498 | ffmpeg -i INPUT -f md5 - | |
499 | @end example | |
500 | ||
501 | See also the @ref{framemd5} muxer. | |
502 | ||
503 | @section mov, mp4, ismv | |
504 | ||
505 | MOV/MP4/ISMV (Smooth Streaming) muxer. | |
506 | ||
507 | The mov/mp4/ismv muxer supports fragmentation. Normally, a MOV/MP4 | |
508 | file has all the metadata about all packets stored in one location | |
509 | (written at the end of the file, it can be moved to the start for | |
510 | better playback by adding @var{faststart} to the @var{movflags}, or | |
511 | using the @command{qt-faststart} tool). A fragmented | |
512 | file consists of a number of fragments, where packets and metadata | |
513 | about these packets are stored together. Writing a fragmented | |
514 | file has the advantage that the file is decodable even if the | |
515 | writing is interrupted (while a normal MOV/MP4 is undecodable if | |
516 | it is not properly finished), and it requires less memory when writing | |
517 | very long files (since writing normal MOV/MP4 files stores info about | |
518 | every single packet in memory until the file is closed). The downside | |
519 | is that it is less compatible with other applications. | |
520 | ||
521 | @subsection Options | |
522 | ||
523 | Fragmentation is enabled by setting one of the AVOptions that define | |
524 | how to cut the file into fragments: | |
525 | ||
526 | @table @option | |
527 | @item -moov_size @var{bytes} | |
528 | Reserves space for the moov atom at the beginning of the file instead of placing the | |
529 | moov atom at the end. If the space reserved is insufficient, muxing will fail. | |
530 | @item -movflags frag_keyframe | |
531 | Start a new fragment at each video keyframe. | |
532 | @item -frag_duration @var{duration} | |
533 | Create fragments that are @var{duration} microseconds long. | |
534 | @item -frag_size @var{size} | |
535 | Create fragments that contain up to @var{size} bytes of payload data. | |
536 | @item -movflags frag_custom | |
537 | Allow the caller to manually choose when to cut fragments, by | |
538 | calling @code{av_write_frame(ctx, NULL)} to write a fragment with | |
539 | the packets written so far. (This is only useful with other | |
540 | applications integrating libavformat, not from @command{ffmpeg}.) | |
541 | @item -min_frag_duration @var{duration} | |
542 | Don't create fragments that are shorter than @var{duration} microseconds long. | |
543 | @end table | |
544 | ||
545 | If more than one condition is specified, fragments are cut when | |
546 | one of the specified conditions is fulfilled. The exception to this is | |
547 | @code{-min_frag_duration}, which has to be fulfilled for any of the other | |
548 | conditions to apply. | |
549 | ||
550 | Additionally, the way the output file is written can be adjusted | |
551 | through a few other options: | |
552 | ||
553 | @table @option | |
554 | @item -movflags empty_moov | |
555 | Write an initial moov atom directly at the start of the file, without | |
556 | describing any samples in it. Generally, an mdat/moov pair is written | |
557 | at the start of the file, as a normal MOV/MP4 file, containing only | |
558 | a short portion of the file. With this option set, there is no initial | |
559 | mdat atom, and the moov atom only describes the tracks but has | |
560 | a zero duration. | |
561 | ||
2ba45a60 DM |
562 | This option is implicitly set when writing ismv (Smooth Streaming) files. |
563 | @item -movflags separate_moof | |
564 | Write a separate moof (movie fragment) atom for each track. Normally, | |
565 | packets for all tracks are written in a moof atom (which is slightly | |
566 | more efficient), but with this option set, the muxer writes one moof/mdat | |
567 | pair for each track, making it easier to separate tracks. | |
568 | ||
569 | This option is implicitly set when writing ismv (Smooth Streaming) files. | |
570 | @item -movflags faststart | |
571 | Run a second pass moving the index (moov atom) to the beginning of the file. | |
572 | This operation can take a while, and will not work in various situations such | |
573 | as fragmented output, thus it is not enabled by default. | |
574 | @item -movflags rtphint | |
575 | Add RTP hinting tracks to the output file. | |
576 | @item -movflags disable_chpl | |
577 | Disable Nero chapter markers (chpl atom). Normally, both Nero chapters | |
578 | and a QuickTime chapter track are written to the file. With this option | |
579 | set, only the QuickTime chapter track will be written. Nero chapters can | |
580 | cause failures when the file is reprocessed with certain tagging programs, like | |
581 | mp3Tag 2.61a and iTunes 11.3, most likely other versions are affected as well. | |
f6fa7814 DM |
582 | @item -movflags omit_tfhd_offset |
583 | Do not write any absolute base_data_offset in tfhd atoms. This avoids | |
584 | tying fragments to absolute byte positions in the file/streams. | |
585 | @item -movflags default_base_moof | |
586 | Similarly to the omit_tfhd_offset, this flag avoids writing the | |
587 | absolute base_data_offset field in tfhd atoms, but does so by using | |
588 | the new default-base-is-moof flag instead. This flag is new from | |
589 | 14496-12:2012. This may make the fragments easier to parse in certain | |
590 | circumstances (avoiding basing track fragment location calculations | |
591 | on the implicit end of the previous track fragment). | |
2ba45a60 DM |
592 | @end table |
593 | ||
594 | @subsection Example | |
595 | ||
596 | Smooth Streaming content can be pushed in real time to a publishing | |
597 | point on IIS with this muxer. Example: | |
598 | @example | |
599 | ffmpeg -re @var{<normal input/transcoding options>} -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1) | |
600 | @end example | |
601 | ||
602 | @section mp3 | |
603 | ||
f6fa7814 DM |
604 | The MP3 muxer writes a raw MP3 stream with the following optional features: |
605 | @itemize @bullet | |
606 | @item | |
607 | An ID3v2 metadata header at the beginning (enabled by default). Versions 2.3 and | |
608 | 2.4 are supported, the @code{id3v2_version} private option controls which one is | |
609 | used (3 or 4). Setting @code{id3v2_version} to 0 disables the ID3v2 header | |
610 | completely. | |
611 | ||
612 | The muxer supports writing attached pictures (APIC frames) to the ID3v2 header. | |
613 | The pictures are supplied to the muxer in form of a video stream with a single | |
614 | packet. There can be any number of those streams, each will correspond to a | |
615 | single APIC frame. The stream metadata tags @var{title} and @var{comment} map | |
616 | to APIC @var{description} and @var{picture type} respectively. See | |
2ba45a60 DM |
617 | @url{http://id3.org/id3v2.4.0-frames} for allowed picture types. |
618 | ||
619 | Note that the APIC frames must be written at the beginning, so the muxer will | |
620 | buffer the audio frames until it gets all the pictures. It is therefore advised | |
621 | to provide the pictures as soon as possible to avoid excessive buffering. | |
622 | ||
f6fa7814 DM |
623 | @item |
624 | A Xing/LAME frame right after the ID3v2 header (if present). It is enabled by | |
625 | default, but will be written only if the output is seekable. The | |
626 | @code{write_xing} private option can be used to disable it. The frame contains | |
627 | various information that may be useful to the decoder, like the audio duration | |
628 | or encoder delay. | |
629 | ||
630 | @item | |
631 | A legacy ID3v1 tag at the end of the file (disabled by default). It may be | |
632 | enabled with the @code{write_id3v1} private option, but as its capabilities are | |
633 | very limited, its usage is not recommended. | |
634 | @end itemize | |
635 | ||
2ba45a60 DM |
636 | Examples: |
637 | ||
638 | Write an mp3 with an ID3v2.3 header and an ID3v1 footer: | |
639 | @example | |
640 | ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3 | |
641 | @end example | |
642 | ||
643 | To attach a picture to an mp3 file select both the audio and the picture stream | |
644 | with @code{map}: | |
645 | @example | |
646 | ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1 | |
647 | -metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3 | |
648 | @end example | |
649 | ||
650 | Write a "clean" MP3 without any extra features: | |
651 | @example | |
652 | ffmpeg -i input.wav -write_xing 0 -id3v2_version 0 out.mp3 | |
653 | @end example | |
654 | ||
655 | @section mpegts | |
656 | ||
657 | MPEG transport stream muxer. | |
658 | ||
659 | This muxer implements ISO 13818-1 and part of ETSI EN 300 468. | |
660 | ||
661 | The recognized metadata settings in mpegts muxer are @code{service_provider} | |
662 | and @code{service_name}. If they are not set the default for | |
663 | @code{service_provider} is "FFmpeg" and the default for | |
664 | @code{service_name} is "Service01". | |
665 | ||
666 | @subsection Options | |
667 | ||
668 | The muxer options are: | |
669 | ||
670 | @table @option | |
671 | @item -mpegts_original_network_id @var{number} | |
672 | Set the original_network_id (default 0x0001). This is unique identifier | |
673 | of a network in DVB. Its main use is in the unique identification of a | |
674 | service through the path Original_Network_ID, Transport_Stream_ID. | |
675 | @item -mpegts_transport_stream_id @var{number} | |
676 | Set the transport_stream_id (default 0x0001). This identifies a | |
677 | transponder in DVB. | |
678 | @item -mpegts_service_id @var{number} | |
679 | Set the service_id (default 0x0001) also known as program in DVB. | |
680 | @item -mpegts_pmt_start_pid @var{number} | |
681 | Set the first PID for PMT (default 0x1000, max 0x1f00). | |
682 | @item -mpegts_start_pid @var{number} | |
683 | Set the first PID for data packets (default 0x0100, max 0x0f00). | |
684 | @item -mpegts_m2ts_mode @var{number} | |
685 | Enable m2ts mode if set to 1. Default value is -1 which disables m2ts mode. | |
686 | @item -muxrate @var{number} | |
687 | Set a constant muxrate (default VBR). | |
688 | @item -pcr_period @var{numer} | |
689 | Override the default PCR retransmission time (default 20ms), ignored | |
690 | if variable muxrate is selected. | |
691 | @item -pes_payload_size @var{number} | |
692 | Set minimum PES packet payload in bytes. | |
693 | @item -mpegts_flags @var{flags} | |
694 | Set flags (see below). | |
695 | @item -mpegts_copyts @var{number} | |
696 | Preserve original timestamps, if value is set to 1. Default value is -1, which | |
697 | results in shifting timestamps so that they start from 0. | |
698 | @item -tables_version @var{number} | |
699 | Set PAT, PMT and SDT version (default 0, valid values are from 0 to 31, inclusively). | |
700 | This option allows updating stream structure so that standard consumer may | |
701 | detect the change. To do so, reopen output AVFormatContext (in case of API | |
702 | usage) or restart ffmpeg instance, cyclically changing tables_version value: | |
703 | @example | |
704 | ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111 | |
705 | ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111 | |
706 | ... | |
707 | ffmpeg -i source3.ts -codec copy -f mpegts -tables_version 31 udp://1.1.1.1:1111 | |
708 | ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111 | |
709 | ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111 | |
710 | ... | |
711 | @end example | |
712 | @end table | |
713 | ||
714 | Option mpegts_flags may take a set of such flags: | |
715 | ||
716 | @table @option | |
717 | @item resend_headers | |
718 | Reemit PAT/PMT before writing the next packet. | |
719 | @item latm | |
720 | Use LATM packetization for AAC. | |
721 | @end table | |
722 | ||
723 | @subsection Example | |
724 | ||
725 | @example | |
726 | ffmpeg -i file.mpg -c copy \ | |
727 | -mpegts_original_network_id 0x1122 \ | |
728 | -mpegts_transport_stream_id 0x3344 \ | |
729 | -mpegts_service_id 0x5566 \ | |
730 | -mpegts_pmt_start_pid 0x1500 \ | |
731 | -mpegts_start_pid 0x150 \ | |
732 | -metadata service_provider="Some provider" \ | |
733 | -metadata service_name="Some Channel" \ | |
734 | -y out.ts | |
735 | @end example | |
736 | ||
737 | @section null | |
738 | ||
739 | Null muxer. | |
740 | ||
741 | This muxer does not generate any output file, it is mainly useful for | |
742 | testing or benchmarking purposes. | |
743 | ||
744 | For example to benchmark decoding with @command{ffmpeg} you can use the | |
745 | command: | |
746 | @example | |
747 | ffmpeg -benchmark -i INPUT -f null out.null | |
748 | @end example | |
749 | ||
750 | Note that the above command does not read or write the @file{out.null} | |
751 | file, but specifying the output file is required by the @command{ffmpeg} | |
752 | syntax. | |
753 | ||
754 | Alternatively you can write the command as: | |
755 | @example | |
756 | ffmpeg -benchmark -i INPUT -f null - | |
757 | @end example | |
758 | ||
759 | @section nut | |
760 | ||
761 | @table @option | |
762 | @item -syncpoints @var{flags} | |
763 | Change the syncpoint usage in nut: | |
764 | @table @option | |
765 | @item @var{default} use the normal low-overhead seeking aids. | |
766 | @item @var{none} do not use the syncpoints at all, reducing the overhead but making the stream non-seekable; | |
767 | Use of this option is not recommended, as the resulting files are very damage | |
768 | sensitive and seeking is not possible. Also in general the overhead from | |
769 | syncpoints is negligible. Note, -@code{write_index} 0 can be used to disable | |
770 | all growing data tables, allowing to mux endless streams with limited memory | |
771 | and wihout these disadvantages. | |
772 | @item @var{timestamped} extend the syncpoint with a wallclock field. | |
773 | @end table | |
774 | The @var{none} and @var{timestamped} flags are experimental. | |
775 | @item -write_index @var{bool} | |
776 | Write index at the end, the default is to write an index. | |
777 | @end table | |
778 | ||
779 | @example | |
780 | ffmpeg -i INPUT -f_strict experimental -syncpoints none - | processor | |
781 | @end example | |
782 | ||
783 | @section ogg | |
784 | ||
785 | Ogg container muxer. | |
786 | ||
787 | @table @option | |
788 | @item -page_duration @var{duration} | |
789 | Preferred page duration, in microseconds. The muxer will attempt to create | |
790 | pages that are approximately @var{duration} microseconds long. This allows the | |
791 | user to compromise between seek granularity and container overhead. The default | |
792 | is 1 second. A value of 0 will fill all segments, making pages as large as | |
793 | possible. A value of 1 will effectively use 1 packet-per-page in most | |
794 | situations, giving a small seek granularity at the cost of additional container | |
795 | overhead. | |
796 | @end table | |
797 | ||
798 | @anchor{segment} | |
799 | @section segment, stream_segment, ssegment | |
800 | ||
801 | Basic stream segmenter. | |
802 | ||
803 | This muxer outputs streams to a number of separate files of nearly | |
804 | fixed duration. Output filename pattern can be set in a fashion similar to | |
805 | @ref{image2}. | |
806 | ||
807 | @code{stream_segment} is a variant of the muxer used to write to | |
808 | streaming output formats, i.e. which do not require global headers, | |
809 | and is recommended for outputting e.g. to MPEG transport stream segments. | |
810 | @code{ssegment} is a shorter alias for @code{stream_segment}. | |
811 | ||
812 | Every segment starts with a keyframe of the selected reference stream, | |
813 | which is set through the @option{reference_stream} option. | |
814 | ||
815 | Note that if you want accurate splitting for a video file, you need to | |
816 | make the input key frames correspond to the exact splitting times | |
817 | expected by the segmenter, or the segment muxer will start the new | |
818 | segment with the key frame found next after the specified start | |
819 | time. | |
820 | ||
821 | The segment muxer works best with a single constant frame rate video. | |
822 | ||
823 | Optionally it can generate a list of the created segments, by setting | |
824 | the option @var{segment_list}. The list type is specified by the | |
825 | @var{segment_list_type} option. The entry filenames in the segment | |
826 | list are set by default to the basename of the corresponding segment | |
827 | files. | |
828 | ||
829 | See also the @ref{hls} muxer, which provides a more specific | |
830 | implementation for HLS segmentation. | |
831 | ||
832 | @subsection Options | |
833 | ||
834 | The segment muxer supports the following options: | |
835 | ||
836 | @table @option | |
837 | @item reference_stream @var{specifier} | |
838 | Set the reference stream, as specified by the string @var{specifier}. | |
839 | If @var{specifier} is set to @code{auto}, the reference is chosen | |
840 | automatically. Otherwise it must be a stream specifier (see the ``Stream | |
841 | specifiers'' chapter in the ffmpeg manual) which specifies the | |
842 | reference stream. The default value is @code{auto}. | |
843 | ||
844 | @item segment_format @var{format} | |
845 | Override the inner container format, by default it is guessed by the filename | |
846 | extension. | |
847 | ||
848 | @item segment_format_options @var{options_list} | |
849 | Set output format options using a :-separated list of key=value | |
850 | parameters. Values containing the @code{:} special character must be | |
851 | escaped. | |
852 | ||
853 | @item segment_list @var{name} | |
854 | Generate also a listfile named @var{name}. If not specified no | |
855 | listfile is generated. | |
856 | ||
857 | @item segment_list_flags @var{flags} | |
858 | Set flags affecting the segment list generation. | |
859 | ||
860 | It currently supports the following flags: | |
861 | @table @samp | |
862 | @item cache | |
863 | Allow caching (only affects M3U8 list files). | |
864 | ||
865 | @item live | |
866 | Allow live-friendly file generation. | |
867 | @end table | |
868 | ||
869 | @item segment_list_type @var{type} | |
870 | Select the listing format. | |
871 | @table @option | |
872 | @item @var{flat} use a simple flat list of entries. | |
873 | @item @var{hls} use a m3u8-like structure. | |
874 | @end table | |
875 | ||
876 | @item segment_list_size @var{size} | |
877 | Update the list file so that it contains at most @var{size} | |
878 | segments. If 0 the list file will contain all the segments. Default | |
879 | value is 0. | |
880 | ||
881 | @item segment_list_entry_prefix @var{prefix} | |
882 | Prepend @var{prefix} to each entry. Useful to generate absolute paths. | |
883 | By default no prefix is applied. | |
884 | ||
885 | The following values are recognized: | |
886 | @table @samp | |
887 | @item flat | |
888 | Generate a flat list for the created segments, one segment per line. | |
889 | ||
890 | @item csv, ext | |
891 | Generate a list for the created segments, one segment per line, | |
892 | each line matching the format (comma-separated values): | |
893 | @example | |
894 | @var{segment_filename},@var{segment_start_time},@var{segment_end_time} | |
895 | @end example | |
896 | ||
897 | @var{segment_filename} is the name of the output file generated by the | |
898 | muxer according to the provided pattern. CSV escaping (according to | |
899 | RFC4180) is applied if required. | |
900 | ||
901 | @var{segment_start_time} and @var{segment_end_time} specify | |
902 | the segment start and end time expressed in seconds. | |
903 | ||
904 | A list file with the suffix @code{".csv"} or @code{".ext"} will | |
905 | auto-select this format. | |
906 | ||
907 | @samp{ext} is deprecated in favor or @samp{csv}. | |
908 | ||
909 | @item ffconcat | |
910 | Generate an ffconcat file for the created segments. The resulting file | |
911 | can be read using the FFmpeg @ref{concat} demuxer. | |
912 | ||
913 | A list file with the suffix @code{".ffcat"} or @code{".ffconcat"} will | |
914 | auto-select this format. | |
915 | ||
916 | @item m3u8 | |
917 | Generate an extended M3U8 file, version 3, compliant with | |
918 | @url{http://tools.ietf.org/id/draft-pantos-http-live-streaming}. | |
919 | ||
920 | A list file with the suffix @code{".m3u8"} will auto-select this format. | |
921 | @end table | |
922 | ||
923 | If not specified the type is guessed from the list file name suffix. | |
924 | ||
925 | @item segment_time @var{time} | |
926 | Set segment duration to @var{time}, the value must be a duration | |
927 | specification. Default value is "2". See also the | |
928 | @option{segment_times} option. | |
929 | ||
930 | Note that splitting may not be accurate, unless you force the | |
931 | reference stream key-frames at the given time. See the introductory | |
932 | notice and the examples below. | |
933 | ||
934 | @item segment_atclocktime @var{1|0} | |
935 | If set to "1" split at regular clock time intervals starting from 00:00 | |
936 | o'clock. The @var{time} value specified in @option{segment_time} is | |
937 | used for setting the length of the splitting interval. | |
938 | ||
939 | For example with @option{segment_time} set to "900" this makes it possible | |
940 | to create files at 12:00 o'clock, 12:15, 12:30, etc. | |
941 | ||
942 | Default value is "0". | |
943 | ||
944 | @item segment_time_delta @var{delta} | |
945 | Specify the accuracy time when selecting the start time for a | |
946 | segment, expressed as a duration specification. Default value is "0". | |
947 | ||
948 | When delta is specified a key-frame will start a new segment if its | |
949 | PTS satisfies the relation: | |
950 | @example | |
951 | PTS >= start_time - time_delta | |
952 | @end example | |
953 | ||
954 | This option is useful when splitting video content, which is always | |
955 | split at GOP boundaries, in case a key frame is found just before the | |
956 | specified split time. | |
957 | ||
958 | In particular may be used in combination with the @file{ffmpeg} option | |
959 | @var{force_key_frames}. The key frame times specified by | |
960 | @var{force_key_frames} may not be set accurately because of rounding | |
961 | issues, with the consequence that a key frame time may result set just | |
962 | before the specified time. For constant frame rate videos a value of | |
963 | 1/(2*@var{frame_rate}) should address the worst case mismatch between | |
964 | the specified time and the time set by @var{force_key_frames}. | |
965 | ||
966 | @item segment_times @var{times} | |
967 | Specify a list of split points. @var{times} contains a list of comma | |
968 | separated duration specifications, in increasing order. See also | |
969 | the @option{segment_time} option. | |
970 | ||
971 | @item segment_frames @var{frames} | |
972 | Specify a list of split video frame numbers. @var{frames} contains a | |
973 | list of comma separated integer numbers, in increasing order. | |
974 | ||
975 | This option specifies to start a new segment whenever a reference | |
976 | stream key frame is found and the sequential number (starting from 0) | |
977 | of the frame is greater or equal to the next value in the list. | |
978 | ||
979 | @item segment_wrap @var{limit} | |
980 | Wrap around segment index once it reaches @var{limit}. | |
981 | ||
982 | @item segment_start_number @var{number} | |
983 | Set the sequence number of the first segment. Defaults to @code{0}. | |
984 | ||
985 | @item reset_timestamps @var{1|0} | |
986 | Reset timestamps at the begin of each segment, so that each segment | |
987 | will start with near-zero timestamps. It is meant to ease the playback | |
988 | of the generated segments. May not work with some combinations of | |
989 | muxers/codecs. It is set to @code{0} by default. | |
990 | ||
991 | @item initial_offset @var{offset} | |
992 | Specify timestamp offset to apply to the output packet timestamps. The | |
993 | argument must be a time duration specification, and defaults to 0. | |
994 | @end table | |
995 | ||
996 | @subsection Examples | |
997 | ||
998 | @itemize | |
999 | @item | |
1000 | Remux the content of file @file{in.mkv} to a list of segments | |
1001 | @file{out-000.nut}, @file{out-001.nut}, etc., and write the list of | |
1002 | generated segments to @file{out.list}: | |
1003 | @example | |
1004 | ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.list out%03d.nut | |
1005 | @end example | |
1006 | ||
1007 | @item | |
1008 | Segment input and set output format options for the output segments: | |
1009 | @example | |
1010 | ffmpeg -i in.mkv -f segment -segment_time 10 -segment_format_options movflags=+faststart out%03d.mp4 | |
1011 | @end example | |
1012 | ||
1013 | @item | |
1014 | Segment the input file according to the split points specified by the | |
1015 | @var{segment_times} option: | |
1016 | @example | |
1017 | ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 out%03d.nut | |
1018 | @end example | |
1019 | ||
1020 | @item | |
1021 | Use the @command{ffmpeg} @option{force_key_frames} | |
1022 | option to force key frames in the input at the specified location, together | |
1023 | with the segment option @option{segment_time_delta} to account for | |
1024 | possible roundings operated when setting key frame times. | |
1025 | @example | |
1026 | ffmpeg -i in.mkv -force_key_frames 1,2,3,5,8,13,21 -codec:v mpeg4 -codec:a pcm_s16le -map 0 \ | |
1027 | -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 -segment_time_delta 0.05 out%03d.nut | |
1028 | @end example | |
1029 | In order to force key frames on the input file, transcoding is | |
1030 | required. | |
1031 | ||
1032 | @item | |
1033 | Segment the input file by splitting the input file according to the | |
1034 | frame numbers sequence specified with the @option{segment_frames} option: | |
1035 | @example | |
1036 | ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_frames 100,200,300,500,800 out%03d.nut | |
1037 | @end example | |
1038 | ||
1039 | @item | |
1040 | Convert the @file{in.mkv} to TS segments using the @code{libx264} | |
1041 | and @code{libfaac} encoders: | |
1042 | @example | |
1043 | ffmpeg -i in.mkv -map 0 -codec:v libx264 -codec:a libfaac -f ssegment -segment_list out.list out%03d.ts | |
1044 | @end example | |
1045 | ||
1046 | @item | |
1047 | Segment the input file, and create an M3U8 live playlist (can be used | |
1048 | as live HLS source): | |
1049 | @example | |
1050 | ffmpeg -re -i in.mkv -codec copy -map 0 -f segment -segment_list playlist.m3u8 \ | |
1051 | -segment_list_flags +live -segment_time 10 out%03d.mkv | |
1052 | @end example | |
1053 | @end itemize | |
1054 | ||
1055 | @section smoothstreaming | |
1056 | ||
1057 | Smooth Streaming muxer generates a set of files (Manifest, chunks) suitable for serving with conventional web server. | |
1058 | ||
1059 | @table @option | |
1060 | @item window_size | |
1061 | Specify the number of fragments kept in the manifest. Default 0 (keep all). | |
1062 | ||
1063 | @item extra_window_size | |
1064 | Specify the number of fragments kept outside of the manifest before removing from disk. Default 5. | |
1065 | ||
1066 | @item lookahead_count | |
1067 | Specify the number of lookahead fragments. Default 2. | |
1068 | ||
1069 | @item min_frag_duration | |
1070 | Specify the minimum fragment duration (in microseconds). Default 5000000. | |
1071 | ||
1072 | @item remove_at_exit | |
1073 | Specify whether to remove all fragments when finished. Default 0 (do not remove). | |
1074 | ||
1075 | @end table | |
1076 | ||
1077 | @section tee | |
1078 | ||
1079 | The tee muxer can be used to write the same data to several files or any | |
1080 | other kind of muxer. It can be used, for example, to both stream a video to | |
1081 | the network and save it to disk at the same time. | |
1082 | ||
1083 | It is different from specifying several outputs to the @command{ffmpeg} | |
1084 | command-line tool because the audio and video data will be encoded only once | |
1085 | with the tee muxer; encoding can be a very expensive process. It is not | |
1086 | useful when using the libavformat API directly because it is then possible | |
1087 | to feed the same packets to several muxers directly. | |
1088 | ||
1089 | The slave outputs are specified in the file name given to the muxer, | |
1090 | separated by '|'. If any of the slave name contains the '|' separator, | |
1091 | leading or trailing spaces or any special character, it must be | |
1092 | escaped (see @ref{quoting_and_escaping,,the "Quoting and escaping" | |
1093 | section in the ffmpeg-utils(1) manual,ffmpeg-utils}). | |
1094 | ||
1095 | Muxer options can be specified for each slave by prepending them as a list of | |
1096 | @var{key}=@var{value} pairs separated by ':', between square brackets. If | |
1097 | the options values contain a special character or the ':' separator, they | |
1098 | must be escaped; note that this is a second level escaping. | |
1099 | ||
1100 | The following special options are also recognized: | |
1101 | @table @option | |
1102 | @item f | |
1103 | Specify the format name. Useful if it cannot be guessed from the | |
1104 | output name suffix. | |
1105 | ||
1106 | @item bsfs[/@var{spec}] | |
1107 | Specify a list of bitstream filters to apply to the specified | |
1108 | output. | |
1109 | ||
1110 | It is possible to specify to which streams a given bitstream filter | |
1111 | applies, by appending a stream specifier to the option separated by | |
1112 | @code{/}. @var{spec} must be a stream specifier (see @ref{Format | |
1113 | stream specifiers}). If the stream specifier is not specified, the | |
1114 | bitstream filters will be applied to all streams in the output. | |
1115 | ||
1116 | Several bitstream filters can be specified, separated by ",". | |
1117 | ||
1118 | @item select | |
1119 | Select the streams that should be mapped to the slave output, | |
1120 | specified by a stream specifier. If not specified, this defaults to | |
1121 | all the input streams. | |
1122 | @end table | |
1123 | ||
1124 | @subsection Examples | |
1125 | ||
1126 | @itemize | |
1127 | @item | |
1128 | Encode something and both archive it in a WebM file and stream it | |
1129 | as MPEG-TS over UDP (the streams need to be explicitly mapped): | |
1130 | @example | |
1131 | ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a | |
1132 | "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/" | |
1133 | @end example | |
1134 | ||
1135 | @item | |
1136 | Use @command{ffmpeg} to encode the input, and send the output | |
1137 | to three different destinations. The @code{dump_extra} bitstream | |
1138 | filter is used to add extradata information to all the output video | |
1139 | keyframes packets, as requested by the MPEG-TS format. The select | |
1140 | option is applied to @file{out.aac} in order to make it contain only | |
1141 | audio packets. | |
1142 | @example | |
1143 | ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac -strict experimental | |
1144 | -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac" | |
1145 | @end example | |
1146 | ||
1147 | @item | |
1148 | As below, but select only stream @code{a:1} for the audio output. Note | |
1149 | that a second level escaping must be performed, as ":" is a special | |
1150 | character used to separate options. | |
1151 | @example | |
1152 | ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac -strict experimental | |
1153 | -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=\'a:1\']out.aac" | |
1154 | @end example | |
1155 | @end itemize | |
1156 | ||
1157 | Note: some codecs may need different options depending on the output format; | |
1158 | the auto-detection of this can not work with the tee muxer. The main example | |
1159 | is the @option{global_header} flag. | |
1160 | ||
1161 | @section webm_dash_manifest | |
1162 | ||
1163 | WebM DASH Manifest muxer. | |
1164 | ||
1165 | This muxer implements the WebM DASH Manifest specification to generate the DASH manifest XML. | |
1166 | ||
1167 | @subsection Options | |
1168 | ||
1169 | This muxer supports the following options: | |
1170 | ||
1171 | @table @option | |
1172 | @item adaptation_sets | |
1173 | This option has the following syntax: "id=x,streams=a,b,c id=y,streams=d,e" where x and y are the | |
1174 | unique identifiers of the adaptation sets and a,b,c,d and e are the indices of the corresponding | |
1175 | audio and video streams. Any number of adaptation sets can be added using this option. | |
1176 | @end table | |
1177 | ||
1178 | @subsection Example | |
1179 | @example | |
1180 | ffmpeg -f webm_dash_manifest -i video1.webm \ | |
1181 | -f webm_dash_manifest -i video2.webm \ | |
1182 | -f webm_dash_manifest -i audio1.webm \ | |
1183 | -f webm_dash_manifest -i audio2.webm \ | |
1184 | -map 0 -map 1 -map 2 -map 3 \ | |
1185 | -c copy \ | |
1186 | -f webm_dash_manifest \ | |
1187 | -adaptation_sets "id=0,streams=0,1 id=1,streams=2,3" \ | |
1188 | manifest.xml | |
1189 | @end example | |
1190 | ||
1191 | @c man end MUXERS |