4 Muxers are configured elements in FFmpeg which allow writing
5 multimedia streams to a particular type of file.
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}.
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}}.
16 The option @code{-formats} of the ff* tools will display the list of
19 A description of some of the currently available muxers follows.
24 CRC (Cyclic Redundancy Check) testing format.
26 This muxer computes and prints the Adler-32 CRC of all the input audio
27 and video frames. By default audio frames are converted to signed
28 16-bit raw audio and video frames to raw video before computing the
31 The output of the muxer consists of a single line of the form:
32 CRC=0x@var{CRC}, where @var{CRC} is a hexadecimal number 0-padded to
33 8 digits containing the CRC for all the decoded input frames.
35 For example to compute the CRC of the input, and store it in the file
38 ffmpeg -i INPUT -f crc out.crc
41 You can print the CRC to stdout with the command:
43 ffmpeg -i INPUT -f crc -
46 You can select the output format of each frame with @command{ffmpeg} by
47 specifying the audio and video codec and format. For example to
48 compute the CRC of the input audio converted to PCM unsigned 8-bit
49 and the input video converted to MPEG-2 video, use the command:
51 ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc -
54 See also the @ref{framecrc} muxer.
59 Per-packet CRC (Cyclic Redundancy Check) testing format.
61 This muxer computes and prints the Adler-32 CRC for each audio
62 and video packet. By default audio frames are converted to signed
63 16-bit raw audio and video frames to raw video before computing the
66 The output of the muxer consists of a line for each audio and video
69 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, 0x@var{CRC}
72 @var{CRC} is a hexadecimal number 0-padded to 8 digits containing the
75 For example to compute the CRC of the audio and video frames in
76 @file{INPUT}, converted to raw audio and video packets, and store it
77 in the file @file{out.crc}:
79 ffmpeg -i INPUT -f framecrc out.crc
82 To print the information to stdout, use the command:
84 ffmpeg -i INPUT -f framecrc -
87 With @command{ffmpeg}, you can select the output format to which the
88 audio and video frames are encoded before computing the CRC for each
89 packet by specifying the audio and video codec. For example, to
90 compute the CRC of each decoded input audio frame converted to PCM
91 unsigned 8-bit and of each decoded input video frame converted to
92 MPEG-2 video, use the command:
94 ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -
97 See also the @ref{crc} muxer.
102 Per-packet MD5 testing format.
104 This muxer computes and prints the MD5 hash for each audio
105 and video packet. By default audio frames are converted to signed
106 16-bit raw audio and video frames to raw video before computing the
109 The output of the muxer consists of a line for each audio and video
112 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, @var{MD5}
115 @var{MD5} is a hexadecimal number representing the computed MD5 hash
118 For example to compute the MD5 of the audio and video frames in
119 @file{INPUT}, converted to raw audio and video packets, and store it
120 in the file @file{out.md5}:
122 ffmpeg -i INPUT -f framemd5 out.md5
125 To print the information to stdout, use the command:
127 ffmpeg -i INPUT -f framemd5 -
130 See also the @ref{md5} muxer.
135 Apple HTTP Live Streaming muxer that segments MPEG-TS according to
136 the HTTP Live Streaming specification.
138 It creates a playlist file and numbered segment files. The output
139 filename specifies the playlist filename; the segment filenames
140 receive the same basename as the playlist, a sequential number and
144 ffmpeg -i in.nut out.m3u8
148 @item -hls_time @var{seconds}
149 Set the segment length in seconds.
150 @item -hls_list_size @var{size}
151 Set the maximum number of playlist entries.
152 @item -hls_wrap @var{wrap}
153 Set the number after which index wraps.
154 @item -start_number @var{number}
155 Start the sequence from @var{number}.
163 Microsoft's icon file format (ICO) has some strict limitations that should be noted:
167 Size cannot exceed 256 pixels in any dimension
170 Only BMP and PNG images can be stored
173 If a BMP image is used, it must be one of the following pixel formats:
175 BMP Bit Depth FFmpeg Pixel Format
185 If a BMP image is used, it must use the BITMAPINFOHEADER DIB header
188 If a PNG image is used, it must use the rgba pixel format
196 The image file muxer writes video frames to image files.
198 The output filenames are specified by a pattern, which can be used to
199 produce sequentially numbered series of files.
200 The pattern may contain the string "%d" or "%0@var{N}d", this string
201 specifies the position of the characters representing a numbering in
202 the filenames. If the form "%0@var{N}d" is used, the string
203 representing the number in each filename is 0-padded to @var{N}
204 digits. The literal character '%' can be specified in the pattern with
207 If the pattern contains "%d" or "%0@var{N}d", the first filename of
208 the file list specified will contain the number 1, all the following
209 numbers will be sequential.
211 The pattern may contain a suffix which is used to automatically
212 determine the format of the image files to write.
214 For example the pattern "img-%03d.bmp" will specify a sequence of
215 filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ...,
216 @file{img-010.bmp}, etc.
217 The pattern "img%%-%d.jpg" will specify a sequence of filenames of the
218 form @file{img%-1.jpg}, @file{img%-2.jpg}, ..., @file{img%-10.jpg},
221 The following example shows how to use @command{ffmpeg} for creating a
222 sequence of files @file{img-001.jpeg}, @file{img-002.jpeg}, ...,
223 taking one image every second from the input video:
225 ffmpeg -i in.avi -vsync 1 -r 1 -f image2 'img-%03d.jpeg'
228 Note that with @command{ffmpeg}, if the format is not specified with the
229 @code{-f} option and the output filename specifies an image file
230 format, the image2 muxer is automatically selected, so the previous
231 command can be written as:
233 ffmpeg -i in.avi -vsync 1 -r 1 'img-%03d.jpeg'
236 Note also that the pattern must not necessarily contain "%d" or
237 "%0@var{N}d", for example to create a single image file
238 @file{img.jpeg} from the input video you can employ the command:
240 ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg
244 @item start_number @var{number}
245 Start the sequence from @var{number}. Default value is 1. Must be a
248 @item -update @var{number}
249 If @var{number} is nonzero, the filename will always be interpreted as just a
250 filename, not a pattern, and this file will be continuously overwritten with new
255 The image muxer supports the .Y.U.V image file format. This format is
256 special in that that each image frame consists of three files, for
257 each of the YUV420P components. To read or write this image file format,
258 specify the name of the '.Y' file. The muxer will automatically open the
259 '.U' and '.V' files as required.
266 This muxer computes and prints the MD5 hash of all the input audio
267 and video frames. By default audio frames are converted to signed
268 16-bit raw audio and video frames to raw video before computing the
271 The output of the muxer consists of a single line of the form:
272 MD5=@var{MD5}, where @var{MD5} is a hexadecimal number representing
273 the computed MD5 hash.
275 For example to compute the MD5 hash of the input converted to raw
276 audio and video, and store it in the file @file{out.md5}:
278 ffmpeg -i INPUT -f md5 out.md5
281 You can print the MD5 to stdout with the command:
283 ffmpeg -i INPUT -f md5 -
286 See also the @ref{framemd5} muxer.
288 @section MOV/MP4/ISMV
290 The mov/mp4/ismv muxer supports fragmentation. Normally, a MOV/MP4
291 file has all the metadata about all packets stored in one location
292 (written at the end of the file, it can be moved to the start for
293 better playback by adding @var{faststart} to the @var{movflags}, or
294 using the @command{qt-faststart} tool). A fragmented
295 file consists of a number of fragments, where packets and metadata
296 about these packets are stored together. Writing a fragmented
297 file has the advantage that the file is decodable even if the
298 writing is interrupted (while a normal MOV/MP4 is undecodable if
299 it is not properly finished), and it requires less memory when writing
300 very long files (since writing normal MOV/MP4 files stores info about
301 every single packet in memory until the file is closed). The downside
302 is that it is less compatible with other applications.
304 Fragmentation is enabled by setting one of the AVOptions that define
305 how to cut the file into fragments:
308 @item -moov_size @var{bytes}
309 Reserves space for the moov atom at the beginning of the file instead of placing the
310 moov atom at the end. If the space reserved is insufficient, muxing will fail.
311 @item -movflags frag_keyframe
312 Start a new fragment at each video keyframe.
313 @item -frag_duration @var{duration}
314 Create fragments that are @var{duration} microseconds long.
315 @item -frag_size @var{size}
316 Create fragments that contain up to @var{size} bytes of payload data.
317 @item -movflags frag_custom
318 Allow the caller to manually choose when to cut fragments, by
319 calling @code{av_write_frame(ctx, NULL)} to write a fragment with
320 the packets written so far. (This is only useful with other
321 applications integrating libavformat, not from @command{ffmpeg}.)
322 @item -min_frag_duration @var{duration}
323 Don't create fragments that are shorter than @var{duration} microseconds long.
326 If more than one condition is specified, fragments are cut when
327 one of the specified conditions is fulfilled. The exception to this is
328 @code{-min_frag_duration}, which has to be fulfilled for any of the other
331 Additionally, the way the output file is written can be adjusted
332 through a few other options:
335 @item -movflags empty_moov
336 Write an initial moov atom directly at the start of the file, without
337 describing any samples in it. Generally, an mdat/moov pair is written
338 at the start of the file, as a normal MOV/MP4 file, containing only
339 a short portion of the file. With this option set, there is no initial
340 mdat atom, and the moov atom only describes the tracks but has
343 Files written with this option set do not work in QuickTime.
344 This option is implicitly set when writing ismv (Smooth Streaming) files.
345 @item -movflags separate_moof
346 Write a separate moof (movie fragment) atom for each track. Normally,
347 packets for all tracks are written in a moof atom (which is slightly
348 more efficient), but with this option set, the muxer writes one moof/mdat
349 pair for each track, making it easier to separate tracks.
351 This option is implicitly set when writing ismv (Smooth Streaming) files.
352 @item -movflags faststart
353 Run a second pass moving the moov atom on top of the file. This
354 operation can take a while, and will not work in various situations such
355 as fragmented output, thus it is not enabled by default.
356 @item -movflags rtphint
357 Add RTP hinting tracks to the output file.
360 Smooth Streaming content can be pushed in real time to a publishing
361 point on IIS with this muxer. Example:
363 ffmpeg -re @var{<normal input/transcoding options>} -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1)
368 MPEG transport stream muxer.
370 This muxer implements ISO 13818-1 and part of ETSI EN 300 468.
372 The muxer options are:
375 @item -mpegts_original_network_id @var{number}
376 Set the original_network_id (default 0x0001). This is unique identifier
377 of a network in DVB. Its main use is in the unique identification of a
378 service through the path Original_Network_ID, Transport_Stream_ID.
379 @item -mpegts_transport_stream_id @var{number}
380 Set the transport_stream_id (default 0x0001). This identifies a
382 @item -mpegts_service_id @var{number}
383 Set the service_id (default 0x0001) also known as program in DVB.
384 @item -mpegts_pmt_start_pid @var{number}
385 Set the first PID for PMT (default 0x1000, max 0x1f00).
386 @item -mpegts_start_pid @var{number}
387 Set the first PID for data packets (default 0x0100, max 0x0f00).
390 The recognized metadata settings in mpegts muxer are @code{service_provider}
391 and @code{service_name}. If they are not set the default for
392 @code{service_provider} is "FFmpeg" and the default for
393 @code{service_name} is "Service01".
396 ffmpeg -i file.mpg -c copy \
397 -mpegts_original_network_id 0x1122 \
398 -mpegts_transport_stream_id 0x3344 \
399 -mpegts_service_id 0x5566 \
400 -mpegts_pmt_start_pid 0x1500 \
401 -mpegts_start_pid 0x150 \
402 -metadata service_provider="Some provider" \
403 -metadata service_name="Some Channel" \
411 This muxer does not generate any output file, it is mainly useful for
412 testing or benchmarking purposes.
414 For example to benchmark decoding with @command{ffmpeg} you can use the
417 ffmpeg -benchmark -i INPUT -f null out.null
420 Note that the above command does not read or write the @file{out.null}
421 file, but specifying the output file is required by the @command{ffmpeg}
424 Alternatively you can write the command as:
426 ffmpeg -benchmark -i INPUT -f null -
431 Matroska container muxer.
433 This muxer implements the matroska and webm container specs.
435 The recognized metadata settings in this muxer are:
439 @item title=@var{title name}
440 Name provided to a single track
445 @item language=@var{language name}
446 Specifies the language of the track in the Matroska languages form
451 @item stereo_mode=@var{mode}
452 Stereo 3D video layout of two views in a single video track
457 Both views are arranged side by side, Left-eye view is on the left
459 Both views are arranged in top-bottom orientation, Left-eye view is at bottom
461 Both views are arranged in top-bottom orientation, Left-eye view is on top
462 @item checkerboard_rl
463 Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first
464 @item checkerboard_lr
465 Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first
466 @item row_interleaved_rl
467 Each view is constituted by a row based interleaving, Right-eye view is first row
468 @item row_interleaved_lr
469 Each view is constituted by a row based interleaving, Left-eye view is first row
470 @item col_interleaved_rl
471 Both views are arranged in a column based interleaving manner, Right-eye view is first column
472 @item col_interleaved_lr
473 Both views are arranged in a column based interleaving manner, Left-eye view is first column
474 @item anaglyph_cyan_red
475 All frames are in anaglyph format viewable through red-cyan filters
477 Both views are arranged side by side, Right-eye view is on the left
478 @item anaglyph_green_magenta
479 All frames are in anaglyph format viewable through green-magenta filters
481 Both eyes laced in one Block, Left-eye view is first
483 Both eyes laced in one Block, Right-eye view is first
487 For example a 3D WebM clip can be created using the following command line:
489 ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm
492 This muxer supports the following options:
496 @item reserve_index_space
497 By default, this muxer writes the index for seeking (called cues in Matroska
498 terms) at the end of the file, because it cannot know in advance how much space
499 to leave for the index at the beginning of the file. However for some use cases
500 -- e.g. streaming where seeking is possible but slow -- it is useful to put the
501 index at the beginning of the file.
503 If this option is set to a non-zero value, the muxer will reserve a given amount
504 of space in the file header and then try to write the cues there when the muxing
505 finishes. If the available space does not suffice, muxing will fail. A safe size
506 for most use cases should be about 50kB per hour of video.
508 Note that cues are only written if the output is seekable and this option will
509 have no effect if it is not.
513 @section segment, stream_segment, ssegment
515 Basic stream segmenter.
517 The segmenter muxer outputs streams to a number of separate files of nearly
518 fixed duration. Output filename pattern can be set in a fashion similar to
521 @code{stream_segment} is a variant of the muxer used to write to
522 streaming output formats, i.e. which do not require global headers,
523 and is recommended for outputting e.g. to MPEG transport stream segments.
524 @code{ssegment} is a shorter alias for @code{stream_segment}.
526 Every segment starts with a keyframe of the selected reference stream,
527 which is set through the @option{reference_stream} option.
529 Note that if you want accurate splitting for a video file, you need to
530 make the input key frames correspond to the exact splitting times
531 expected by the segmenter, or the segment muxer will start the new
532 segment with the key frame found next after the specified start
535 The segment muxer works best with a single constant frame rate video.
537 Optionally it can generate a list of the created segments, by setting
538 the option @var{segment_list}. The list type is specified by the
539 @var{segment_list_type} option.
541 The segment muxer supports the following options:
544 @item reference_stream @var{specifier}
545 Set the reference stream, as specified by the string @var{specifier}.
546 If @var{specifier} is set to @code{auto}, the reference is choosen
547 automatically. Otherwise it must be a stream specifier (see the ``Stream
548 specifiers'' chapter in the ffmpeg manual) which specifies the
549 reference stream. The default value is ``auto''.
551 @item segment_format @var{format}
552 Override the inner container format, by default it is guessed by the filename
555 @item segment_list @var{name}
556 Generate also a listfile named @var{name}. If not specified no
557 listfile is generated.
559 @item segment_list_flags @var{flags}
560 Set flags affecting the segment list generation.
562 It currently supports the following flags:
565 Allow caching (only affects M3U8 list files).
568 Allow live-friendly file generation.
571 Default value is @code{cache}.
573 @item segment_list_size @var{size}
574 Update the list file so that it contains at most the last @var{size}
575 segments. If 0 the list file will contain all the segments. Default
578 @item segment_list type @var{type}
579 Specify the format for the segment list file.
581 The following values are recognized:
584 Generate a flat list for the created segments, one segment per line.
587 Generate a list for the created segments, one segment per line,
588 each line matching the format (comma-separated values):
590 @var{segment_filename},@var{segment_start_time},@var{segment_end_time}
593 @var{segment_filename} is the name of the output file generated by the
594 muxer according to the provided pattern. CSV escaping (according to
595 RFC4180) is applied if required.
597 @var{segment_start_time} and @var{segment_end_time} specify
598 the segment start and end time expressed in seconds.
600 A list file with the suffix @code{".csv"} or @code{".ext"} will
601 auto-select this format.
603 @code{ext} is deprecated in favor or @code{csv}.
606 Generate an ffconcat file for the created segments. The resulting file
607 can be read using the FFmpeg @ref{concat} demuxer.
609 A list file with the suffix @code{".ffcat"} or @code{".ffconcat"} will
610 auto-select this format.
613 Generate an extended M3U8 file, version 3, compliant with
614 @url{http://tools.ietf.org/id/draft-pantos-http-live-streaming}.
616 A list file with the suffix @code{".m3u8"} will auto-select this format.
619 If not specified the type is guessed from the list file name suffix.
621 @item segment_time @var{time}
622 Set segment duration to @var{time}, the value must be a duration
623 specification. Default value is "2". See also the
624 @option{segment_times} option.
626 Note that splitting may not be accurate, unless you force the
627 reference stream key-frames at the given time. See the introductory
628 notice and the examples below.
630 @item segment_time_delta @var{delta}
631 Specify the accuracy time when selecting the start time for a
632 segment, expressed as a duration specification. Default value is "0".
634 When delta is specified a key-frame will start a new segment if its
635 PTS satisfies the relation:
637 PTS >= start_time - time_delta
640 This option is useful when splitting video content, which is always
641 split at GOP boundaries, in case a key frame is found just before the
642 specified split time.
644 In particular may be used in combination with the @file{ffmpeg} option
645 @var{force_key_frames}. The key frame times specified by
646 @var{force_key_frames} may not be set accurately because of rounding
647 issues, with the consequence that a key frame time may result set just
648 before the specified time. For constant frame rate videos a value of
649 1/2*@var{frame_rate} should address the worst case mismatch between
650 the specified time and the time set by @var{force_key_frames}.
652 @item segment_times @var{times}
653 Specify a list of split points. @var{times} contains a list of comma
654 separated duration specifications, in increasing order. See also
655 the @option{segment_time} option.
657 @item segment_frames @var{frames}
658 Specify a list of split video frame numbers. @var{frames} contains a
659 list of comma separated integer numbers, in increasing order.
661 This option specifies to start a new segment whenever a reference
662 stream key frame is found and the sequential number (starting from 0)
663 of the frame is greater or equal to the next value in the list.
665 @item segment_wrap @var{limit}
666 Wrap around segment index once it reaches @var{limit}.
668 @item segment_start_number @var{number}
669 Set the sequence number of the first segment. Defaults to @code{0}.
671 @item reset_timestamps @var{1|0}
672 Reset timestamps at the begin of each segment, so that each segment
673 will start with near-zero timestamps. It is meant to ease the playback
674 of the generated segments. May not work with some combinations of
675 muxers/codecs. It is set to @code{0} by default.
682 To remux the content of file @file{in.mkv} to a list of segments
683 @file{out-000.nut}, @file{out-001.nut}, etc., and write the list of
684 generated segments to @file{out.list}:
686 ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.list out%03d.nut
690 As the example above, but segment the input file according to the split
691 points specified by the @var{segment_times} option:
693 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
697 As the example above, but use the @code{ffmpeg} @var{force_key_frames}
698 option to force key frames in the input at the specified location, together
699 with the segment option @var{segment_time_delta} to account for
700 possible roundings operated when setting key frame times.
702 ffmpeg -i in.mkv -force_key_frames 1,2,3,5,8,13,21 -codec:v mpeg4 -codec:a pcm_s16le -map 0 \
703 -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 -segment_time_delta 0.05 out%03d.nut
705 In order to force key frames on the input file, transcoding is
709 Segment the input file by splitting the input file according to the
710 frame numbers sequence specified with the @var{segment_frames} option:
712 ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_frames 100,200,300,500,800 out%03d.nut
716 To convert the @file{in.mkv} to TS segments using the @code{libx264}
717 and @code{libfaac} encoders:
719 ffmpeg -i in.mkv -map 0 -codec:v libx264 -codec:a libfaac -f ssegment -segment_list out.list out%03d.ts
723 Segment the input file, and create an M3U8 live playlist (can be used
726 ffmpeg -re -i in.mkv -codec copy -map 0 -f segment -segment_list playlist.m3u8 \
727 -segment_list_flags +live -segment_time 10 out%03d.mkv
733 The MP3 muxer writes a raw MP3 stream with an ID3v2 header at the beginning and
734 optionally an ID3v1 tag at the end. ID3v2.3 and ID3v2.4 are supported, the
735 @code{id3v2_version} option controls which one is used. The legacy ID3v1 tag is
736 not written by default, but may be enabled with the @code{write_id3v1} option.
738 For seekable output the muxer also writes a Xing frame at the beginning, which
739 contains the number of frames in the file. It is useful for computing duration
742 The muxer supports writing ID3v2 attached pictures (APIC frames). The pictures
743 are supplied to the muxer in form of a video stream with a single packet. There
744 can be any number of those streams, each will correspond to a single APIC frame.
745 The stream metadata tags @var{title} and @var{comment} map to APIC
746 @var{description} and @var{picture type} respectively. See
747 @url{http://id3.org/id3v2.4.0-frames} for allowed picture types.
749 Note that the APIC frames must be written at the beginning, so the muxer will
750 buffer the audio frames until it gets all the pictures. It is therefore advised
751 to provide the pictures as soon as possible to avoid excessive buffering.
755 Write an mp3 with an ID3v2.3 header and an ID3v1 footer:
757 ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3
760 To attach a picture to an mp3 file select both the audio and the picture stream
763 ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1
764 -metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3
772 @item -page_duration @var{duration}
773 Preferred page duration, in microseconds. The muxer will attempt to create
774 pages that are approximately @var{duration} microseconds long. This allows the
775 user to compromise between seek granularity and container overhead. The default
776 is 1 second. A value of 0 will fill all segments, making pages as large as
777 possible. A value of 1 will effectively use 1 packet-per-page in most
778 situations, giving a small seek granularity at the cost of additional container
784 The tee muxer can be used to write the same data to several files or any
785 other kind of muxer. It can be used, for example, to both stream a video to
786 the network and save it to disk at the same time.
788 It is different from specifying several outputs to the @command{ffmpeg}
789 command-line tool because the audio and video data will be encoded only once
790 with the tee muxer; encoding can be a very expensive process. It is not
791 useful when using the libavformat API directly because it is then possible
792 to feed the same packets to several muxers directly.
794 The slave outputs are specified in the file name given to the muxer,
795 separated by '|'. If any of the slave name contains the '|' separator,
796 leading or trailing spaces or any special character, it must be
797 escaped (see the ``Quoting and escaping'' section in the ffmpeg-utils
800 Options can be specified for each slave by prepending them as a list of
801 @var{key}=@var{value} pairs separated by ':', between square brackets. If
802 the options values contain a special character or the ':' separator, they
803 must be escaped; note that this is a second level escaping.
805 Example: encode something and both archive it in a WebM file and stream it
806 as MPEG-TS over UDP (the streams need to be explicitly mapped):
809 ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
810 "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
813 Note: some codecs may need different options depending on the output format;
814 the auto-detection of this can not work with the tee muxer. The main example
815 is the @option{global_header} flag.