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{-muxers} of the ff* tools will display the list of
17 enabled muxers. Use @code{-formats} to view a combined list of
18 enabled demuxers and muxers.
20 A description of some of the currently available muxers follows.
25 Audio Interchange File Format muxer.
29 It accepts the following options:
33 Enable ID3v2 tags writing when set to 1. Default is 0 (disabled).
36 Select ID3v2 version to write. Currently only version 3 and 4 (aka.
37 ID3v2.3 and ID3v2.4) are supported. The default is version 4.
44 Advanced Systems Format muxer.
46 Note that Windows Media Audio (wma) and Windows Media Video (wmv) use this
51 It accepts the following options:
55 Set the muxer packet size. By tuning this setting you may reduce data
56 fragmentation or muxer overhead depending on your source. Default value is
57 3200, minimum is 100, maximum is 64k.
64 Audio Video Interleaved muxer.
68 It accepts the following options:
71 @item reserve_index_space
72 Reserve the specified amount of bytes for the OpenDML master index of each
73 stream within the file header. By default additional master indexes are
74 embedded within the data packets if there is no space left in the first master
75 index and are linked together as a chain of indexes. This index structure can
76 cause problems for some use cases, e.g. third-party software strictly relying
77 on the OpenDML index specification or when file seeking is slow. Reserving
78 enough index space in the file header avoids these problems.
80 The required index space depends on the output file size and should be about 16
81 bytes per gigabyte. When this option is omitted or set to zero the necessary
82 index space is guessed.
84 @item write_channel_mask
85 Write the channel layout mask into the audio stream header.
87 This option is enabled by default. Disabling the channel mask can be useful in
88 specific scenarios, e.g. when merging multiple audio streams into one for
89 compatibility with software that only supports a single audio stream in AVI
90 (see @ref{amerge,,the "amerge" section in the ffmpeg-filters manual,ffmpeg-filters}).
97 Chromaprint fingerprinter
99 This muxer feeds audio data to the Chromaprint library, which generates
100 a fingerprint for the provided audio data. It takes a single signed
101 native-endian 16-bit raw audio stream.
106 @item silence_threshold
107 Threshold for detecting silence, ranges from 0 to 32767. -1 for default
108 (required for use with the AcoustID service).
111 Algorithm index to fingerprint with.
114 Format to output the fingerprint as. Accepts the following options:
117 Binary raw fingerprint
120 Binary compressed fingerprint
123 Base64 compressed fingerprint
132 CRC (Cyclic Redundancy Check) testing format.
134 This muxer computes and prints the Adler-32 CRC of all the input audio
135 and video frames. By default audio frames are converted to signed
136 16-bit raw audio and video frames to raw video before computing the
139 The output of the muxer consists of a single line of the form:
140 CRC=0x@var{CRC}, where @var{CRC} is a hexadecimal number 0-padded to
141 8 digits containing the CRC for all the decoded input frames.
143 See also the @ref{framecrc} muxer.
147 For example to compute the CRC of the input, and store it in the file
150 ffmpeg -i INPUT -f crc out.crc
153 You can print the CRC to stdout with the command:
155 ffmpeg -i INPUT -f crc -
158 You can select the output format of each frame with @command{ffmpeg} by
159 specifying the audio and video codec and format. For example to
160 compute the CRC of the input audio converted to PCM unsigned 8-bit
161 and the input video converted to MPEG-2 video, use the command:
163 ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc -
168 Adobe Flash Video Format muxer.
170 This muxer accepts the following options:
174 @item flvflags @var{flags}
179 @item aac_seq_header_detect
180 Place AAC sequence header based on audio stream data.
182 @item no_sequence_end
183 Disable sequence end tag.
186 Disable metadata tag.
188 @item no_duration_filesize
189 Disable duration and filesize in metadata when they are equal to zero
190 at the end of stream. (Be used to non-seekable living stream).
192 @item add_keyframe_index
193 Used to facilitate seeking; particularly for HTTP pseudo streaming.
200 Per-packet CRC (Cyclic Redundancy Check) testing format.
202 This muxer computes and prints the Adler-32 CRC for each audio
203 and video packet. By default audio frames are converted to signed
204 16-bit raw audio and video frames to raw video before computing the
207 The output of the muxer consists of a line for each audio and video
210 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, 0x@var{CRC}
213 @var{CRC} is a hexadecimal number 0-padded to 8 digits containing the
218 For example to compute the CRC of the audio and video frames in
219 @file{INPUT}, converted to raw audio and video packets, and store it
220 in the file @file{out.crc}:
222 ffmpeg -i INPUT -f framecrc out.crc
225 To print the information to stdout, use the command:
227 ffmpeg -i INPUT -f framecrc -
230 With @command{ffmpeg}, you can select the output format to which the
231 audio and video frames are encoded before computing the CRC for each
232 packet by specifying the audio and video codec. For example, to
233 compute the CRC of each decoded input audio frame converted to PCM
234 unsigned 8-bit and of each decoded input video frame converted to
235 MPEG-2 video, use the command:
237 ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -
240 See also the @ref{crc} muxer.
245 Per-packet hash testing format.
247 This muxer computes and prints a cryptographic hash for each audio
248 and video packet. This can be used for packet-by-packet equality
249 checks without having to individually do a binary comparison on each.
251 By default audio frames are converted to signed 16-bit raw audio and
252 video frames to raw video before computing the hash, but the output
253 of explicit conversions to other codecs can also be used. It uses the
254 SHA-256 cryptographic hash function by default, but supports several
257 The output of the muxer consists of a line for each audio and video
260 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, @var{hash}
263 @var{hash} is a hexadecimal number representing the computed hash
267 @item hash @var{algorithm}
268 Use the cryptographic hash function specified by the string @var{algorithm}.
269 Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
270 @code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
271 @code{SHA224}, @code{SHA256} (default), @code{SHA512/224}, @code{SHA512/256},
272 @code{SHA384}, @code{SHA512}, @code{CRC32} and @code{adler32}.
278 To compute the SHA-256 hash of the audio and video frames in @file{INPUT},
279 converted to raw audio and video packets, and store it in the file
282 ffmpeg -i INPUT -f framehash out.sha256
285 To print the information to stdout, using the MD5 hash function, use
288 ffmpeg -i INPUT -f framehash -hash md5 -
291 See also the @ref{hash} muxer.
296 Per-packet MD5 testing format.
298 This is a variant of the @ref{framehash} muxer. Unlike that muxer,
299 it defaults to using the MD5 hash function.
303 To compute the MD5 hash of the audio and video frames in @file{INPUT},
304 converted to raw audio and video packets, and store it in the file
307 ffmpeg -i INPUT -f framemd5 out.md5
310 To print the information to stdout, use the command:
312 ffmpeg -i INPUT -f framemd5 -
315 See also the @ref{framehash} and @ref{md5} muxers.
322 It accepts the following options:
326 Set the number of times to loop the output. Use @code{-1} for no loop, @code{0}
327 for looping indefinitely (default).
330 Force the delay (expressed in centiseconds) after the last frame. Each frame
331 ends with a delay until the next frame. The default is @code{-1}, which is a
332 special value to tell the muxer to re-use the previous delay. In case of a
333 loop, you might want to customize this value to mark a pause for instance.
336 For example, to encode a gif looping 10 times, with a 5 seconds delay between
339 ffmpeg -i INPUT -loop 10 -final_delay 500 out.gif
342 Note 1: if you wish to extract the frames into separate GIF files, you need to
343 force the @ref{image2} muxer:
345 ffmpeg -i INPUT -c:v gif -f image2 "out%d.gif"
348 Note 2: the GIF format has a very large time base: the delay between two frames
349 can therefore not be smaller than one centi second.
356 This muxer computes and prints a cryptographic hash of all the input
357 audio and video frames. This can be used for equality checks without
358 having to do a complete binary comparison.
360 By default audio frames are converted to signed 16-bit raw audio and
361 video frames to raw video before computing the hash, but the output
362 of explicit conversions to other codecs can also be used. Timestamps
363 are ignored. It uses the SHA-256 cryptographic hash function by default,
364 but supports several other algorithms.
366 The output of the muxer consists of a single line of the form:
367 @var{algo}=@var{hash}, where @var{algo} is a short string representing
368 the hash function used, and @var{hash} is a hexadecimal number
369 representing the computed hash.
372 @item hash @var{algorithm}
373 Use the cryptographic hash function specified by the string @var{algorithm}.
374 Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
375 @code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
376 @code{SHA224}, @code{SHA256} (default), @code{SHA512/224}, @code{SHA512/256},
377 @code{SHA384}, @code{SHA512}, @code{CRC32} and @code{adler32}.
383 To compute the SHA-256 hash of the input converted to raw audio and
384 video, and store it in the file @file{out.sha256}:
386 ffmpeg -i INPUT -f hash out.sha256
389 To print an MD5 hash to stdout use the command:
391 ffmpeg -i INPUT -f hash -hash md5 -
394 See also the @ref{framehash} muxer.
399 Apple HTTP Live Streaming muxer that segments MPEG-TS according to
400 the HTTP Live Streaming (HLS) specification.
402 It creates a playlist file, and one or more segment files. The output filename
403 specifies the playlist filename.
405 By default, the muxer creates a file for each segment produced. These files
406 have the same name as the playlist, followed by a sequential number and a
409 For example, to convert an input file with @command{ffmpeg}:
411 ffmpeg -i in.nut out.m3u8
413 This example will produce the playlist, @file{out.m3u8}, and segment files:
414 @file{out0.ts}, @file{out1.ts}, @file{out2.ts}, etc.
416 See also the @ref{segment} muxer, which provides a more generic and
417 flexible implementation of a segmenter, and can be used to perform HLS
422 This muxer supports the following options:
425 @item hls_init_time @var{seconds}
426 Set the initial target segment length in seconds. Default value is @var{0}.
427 Segment will be cut on the next key frame after this time has passed on the first m3u8 list.
428 After the initial playlist is filled @command{ffmpeg} will cut segments
429 at duration equal to @code{hls_time}
431 @item hls_time @var{seconds}
432 Set the target segment length in seconds. Default value is 2.
433 Segment will be cut on the next key frame after this time has passed.
435 @item hls_list_size @var{size}
436 Set the maximum number of playlist entries. If set to 0 the list file
437 will contain all the segments. Default value is 5.
439 @item hls_ts_options @var{options_list}
440 Set output format options using a :-separated list of key=value
441 parameters. Values containing @code{:} special characters must be
444 @item hls_wrap @var{wrap}
445 This is a deprecated option, you can use @code{hls_list_size}
446 and @code{hls_flags delete_segments} instead it
448 This option is useful to avoid to fill the disk with many segment
449 files, and limits the maximum number of segment files written to disk
453 @item hls_start_number_source
454 Start the playlist sequence number (@code{#EXT-X-MEDIA-SEQUENCE}) according to the specified source.
455 Unless @code{hls_flags single_file} is set, it also specifies source of starting sequence numbers of
456 segment and subtitle filenames. In any case, if @code{hls_flags append_list}
457 is set and read playlist sequence number is greater than the specified start sequence number,
458 then that value will be used as start value.
460 It accepts the following values:
464 @item generic (default)
465 Set the starting sequence numbers according to @var{start_number} option value.
468 The start number will be the seconds since epoch (1970-01-01 00:00:00)
471 The start number will be based on the current date/time as YYYYmmddHHMMSS. e.g. 20161231235759.
475 @item start_number @var{number}
476 Start the playlist sequence number (@code{#EXT-X-MEDIA-SEQUENCE}) from the specified @var{number}
477 when @var{hls_start_number_source} value is @var{generic}. (This is the default case.)
478 Unless @code{hls_flags single_file} is set, it also specifies starting sequence numbers of segment and subtitle filenames.
481 @item hls_allow_cache @var{allowcache}
482 Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments.
484 @item hls_base_url @var{baseurl}
485 Append @var{baseurl} to every entry in the playlist.
486 Useful to generate playlists with absolute paths.
488 Note that the playlist sequence number must be unique for each segment
489 and it is not to be confused with the segment filename sequence number
490 which can be cyclic, for example if the @option{wrap} option is
493 @item hls_segment_filename @var{filename}
494 Set the segment filename. Unless @code{hls_flags single_file} is set,
495 @var{filename} is used as a string format with the segment number:
497 ffmpeg -i in.nut -hls_segment_filename 'file%03d.ts' out.m3u8
499 This example will produce the playlist, @file{out.m3u8}, and segment files:
500 @file{file000.ts}, @file{file001.ts}, @file{file002.ts}, etc.
502 @var{filename} may contain full path or relative path specification,
503 but only the file name part without any path info will be contained in the m3u8 segment list.
504 Should a relative path be specified, the path of the created segment
505 files will be relative to the current working directory.
506 When use_localtime_mkdir is set, the whole expanded value of @var{filename} will be written into the m3u8 segment list.
510 Use strftime() on @var{filename} to expand the segment filename with localtime.
511 The segment number is also available in this mode, but to use it, you need to specify second_level_segment_index
512 hls_flag and %%d will be the specifier.
514 ffmpeg -i in.nut -use_localtime 1 -hls_segment_filename 'file-%Y%m%d-%s.ts' out.m3u8
516 This example will produce the playlist, @file{out.m3u8}, and segment files:
517 @file{file-20160215-1455569023.ts}, @file{file-20160215-1455569024.ts}, etc.
518 Note: On some systems/environments, the @code{%s} specifier is not available. See
519 @code{strftime()} documentation.
521 ffmpeg -i in.nut -use_localtime 1 -hls_flags second_level_segment_index -hls_segment_filename 'file-%Y%m%d-%%04d.ts' out.m3u8
523 This example will produce the playlist, @file{out.m3u8}, and segment files:
524 @file{file-20160215-0001.ts}, @file{file-20160215-0002.ts}, etc.
526 @item use_localtime_mkdir
527 Used together with -use_localtime, it will create all subdirectories which
528 is expanded in @var{filename}.
530 ffmpeg -i in.nut -use_localtime 1 -use_localtime_mkdir 1 -hls_segment_filename '%Y%m%d/file-%Y%m%d-%s.ts' out.m3u8
532 This example will create a directory 201560215 (if it does not exist), and then
533 produce the playlist, @file{out.m3u8}, and segment files:
534 @file{20160215/file-20160215-1455569023.ts}, @file{20160215/file-20160215-1455569024.ts}, etc.
537 ffmpeg -i in.nut -use_localtime 1 -use_localtime_mkdir 1 -hls_segment_filename '%Y/%m/%d/file-%Y%m%d-%s.ts' out.m3u8
539 This example will create a directory hierarchy 2016/02/15 (if any of them do not exist), and then
540 produce the playlist, @file{out.m3u8}, and segment files:
541 @file{2016/02/15/file-20160215-1455569023.ts}, @file{2016/02/15/file-20160215-1455569024.ts}, etc.
544 @item hls_key_info_file @var{key_info_file}
545 Use the information in @var{key_info_file} for segment encryption. The first
546 line of @var{key_info_file} specifies the key URI written to the playlist. The
547 key URL is used to access the encryption key during playback. The second line
548 specifies the path to the key file used to obtain the key during the encryption
549 process. The key file is read as a single packed array of 16 octets in binary
550 format. The optional third line specifies the initialization vector (IV) as a
551 hexadecimal string to be used instead of the segment sequence number (default)
552 for encryption. Changes to @var{key_info_file} will result in segment
553 encryption with the new key/IV and an entry in the playlist for the new key
554 URI/IV if @code{hls_flags periodic_rekey} is enabled.
556 Key info file format:
565 http://server/file.key
570 Example key file paths:
578 0123456789ABCDEF0123456789ABCDEF
581 Key info file example:
583 http://server/file.key
585 0123456789ABCDEF0123456789ABCDEF
588 Example shell script:
592 openssl rand 16 > file.key
593 echo $BASE_URL/file.key > file.keyinfo
594 echo file.key >> file.keyinfo
595 echo $(openssl rand -hex 16) >> file.keyinfo
596 ffmpeg -f lavfi -re -i testsrc -c:v h264 -hls_flags delete_segments \
597 -hls_key_info_file file.keyinfo out.m3u8
600 @item -hls_enc @var{enc}
601 Enable (1) or disable (0) the AES128 encryption.
602 When enabled every segment generated is encrypted and the encryption key
603 is saved as @var{playlist name}.key.
605 @item -hls_enc_key @var{key}
606 Hex-coded 16byte key to encrypt the segments, by default it
607 is randomly generated.
609 @item -hls_enc_key_url @var{keyurl}
610 If set, @var{keyurl} is prepended instead of @var{baseurl} to the key filename
613 @item -hls_enc_iv @var{iv}
614 Hex-coded 16byte initialization vector for every segment instead
615 of the autogenerated ones.
617 @item hls_segment_type @var{flags}
622 If this flag is set, the hls segment files will format to mpegts.
623 the mpegts files is used in all hls versions.
626 If this flag is set, the hls segment files will format to fragment mp4 looks like dash.
627 the fmp4 files is used in hls after version 7.
631 @item hls_fmp4_init_filename @var{filename}
632 set filename to the fragment files header file, default filename is @file{init.mp4}.
634 @item hls_flags @var{flags}
639 If this flag is set, the muxer will store all segments in a single MPEG-TS
640 file, and will use byte ranges in the playlist. HLS playlists generated with
641 this way will have the version number 4.
644 ffmpeg -i in.nut -hls_flags single_file out.m3u8
646 Will produce the playlist, @file{out.m3u8}, and a single segment file,
649 @item delete_segments
650 Segment files removed from the playlist are deleted after a period of time
651 equal to the duration of the segment plus the duration of the playlist.
654 Append new segments into the end of old segment list,
655 and remove the @code{#EXT-X-ENDLIST} from the old segment list.
657 @item round_durations
658 Round the duration info in the playlist file segment info to integer
659 values, instead of using floating point.
662 Add the @code{#EXT-X-DISCONTINUITY} tag to the playlist, before the
663 first segment's information.
666 Do not append the @code{EXT-X-ENDLIST} tag at the end of the playlist.
669 The file specified by @code{hls_key_info_file} will be checked periodically and
670 detect updates to the encryption info. Be sure to replace this file atomically,
671 including the file containing the AES encryption key.
674 Allow segments to start on frames other than keyframes. This improves
675 behavior on some players when the time between keyframes is inconsistent,
676 but may make things worse on others, and can cause some oddities during
677 seeking. This flag should be used with the @code{hls_time} option.
679 @item program_date_time
680 Generate @code{EXT-X-PROGRAM-DATE-TIME} tags.
682 @item second_level_segment_index
683 Makes it possible to use segment indexes as %%d in hls_segment_filename expression
684 besides date/time values when use_localtime is on.
685 To get fixed width numbers with trailing zeroes, %%0xd format is available where x is the required width.
687 @item second_level_segment_size
688 Makes it possible to use segment sizes (counted in bytes) as %%s in hls_segment_filename
689 expression besides date/time values when use_localtime is on.
690 To get fixed width numbers with trailing zeroes, %%0xs format is available where x is the required width.
692 @item second_level_segment_duration
693 Makes it possible to use segment duration (calculated in microseconds) as %%t in hls_segment_filename
694 expression besides date/time values when use_localtime is on.
695 To get fixed width numbers with trailing zeroes, %%0xt format is available where x is the required width.
698 ffmpeg -i sample.mpeg \
699 -f hls -hls_time 3 -hls_list_size 5 \
700 -hls_flags second_level_segment_index+second_level_segment_size+second_level_segment_duration \
701 -use_localtime 1 -use_localtime_mkdir 1 -hls_segment_filename "segment_%Y%m%d%H%M%S_%%04d_%%08s_%%013t.ts" stream.m3u8
703 This will produce segments like this:
704 @file{segment_20170102194334_0003_00122200_0000003000000.ts}, @file{segment_20170102194334_0004_00120072_0000003000000.ts} etc.
707 Write segment data to filename.tmp and rename to filename only once the segment is complete. A webserver
708 serving up segments can be configured to reject requests to *.tmp to prevent access to in-progress segments
709 before they have been added to the m3u8 playlist.
713 @item hls_playlist_type event
714 Emit @code{#EXT-X-PLAYLIST-TYPE:EVENT} in the m3u8 header. Forces
715 @option{hls_list_size} to 0; the playlist can only be appended to.
717 @item hls_playlist_type vod
718 Emit @code{#EXT-X-PLAYLIST-TYPE:VOD} in the m3u8 header. Forces
719 @option{hls_list_size} to 0; the playlist must not change.
722 Use the given HTTP method to create the hls files.
724 ffmpeg -re -i in.ts -f hls -method PUT http://example.com/live/out.m3u8
726 This example will upload all the mpegts segment files to the HTTP
727 server using the HTTP PUT method, and update the m3u8 files every
728 @code{refresh} times using the same method.
729 Note that the HTTP server must support the given method for uploading
732 @item http_user_agent
733 Override User-Agent field in HTTP header. Applicable only for HTTP output.
742 Microsoft's icon file format (ICO) has some strict limitations that should be noted:
746 Size cannot exceed 256 pixels in any dimension
749 Only BMP and PNG images can be stored
752 If a BMP image is used, it must be one of the following pixel formats:
754 BMP Bit Depth FFmpeg Pixel Format
764 If a BMP image is used, it must use the BITMAPINFOHEADER DIB header
767 If a PNG image is used, it must use the rgba pixel format
775 The image file muxer writes video frames to image files.
777 The output filenames are specified by a pattern, which can be used to
778 produce sequentially numbered series of files.
779 The pattern may contain the string "%d" or "%0@var{N}d", this string
780 specifies the position of the characters representing a numbering in
781 the filenames. If the form "%0@var{N}d" is used, the string
782 representing the number in each filename is 0-padded to @var{N}
783 digits. The literal character '%' can be specified in the pattern with
786 If the pattern contains "%d" or "%0@var{N}d", the first filename of
787 the file list specified will contain the number 1, all the following
788 numbers will be sequential.
790 The pattern may contain a suffix which is used to automatically
791 determine the format of the image files to write.
793 For example the pattern "img-%03d.bmp" will specify a sequence of
794 filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ...,
795 @file{img-010.bmp}, etc.
796 The pattern "img%%-%d.jpg" will specify a sequence of filenames of the
797 form @file{img%-1.jpg}, @file{img%-2.jpg}, ..., @file{img%-10.jpg},
802 The following example shows how to use @command{ffmpeg} for creating a
803 sequence of files @file{img-001.jpeg}, @file{img-002.jpeg}, ...,
804 taking one image every second from the input video:
806 ffmpeg -i in.avi -vsync cfr -r 1 -f image2 'img-%03d.jpeg'
809 Note that with @command{ffmpeg}, if the format is not specified with the
810 @code{-f} option and the output filename specifies an image file
811 format, the image2 muxer is automatically selected, so the previous
812 command can be written as:
814 ffmpeg -i in.avi -vsync cfr -r 1 'img-%03d.jpeg'
817 Note also that the pattern must not necessarily contain "%d" or
818 "%0@var{N}d", for example to create a single image file
819 @file{img.jpeg} from the start of the input video you can employ the command:
821 ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg
824 The @option{strftime} option allows you to expand the filename with
825 date and time information. Check the documentation of
826 the @code{strftime()} function for the syntax.
828 For example to generate image files from the @code{strftime()}
829 "%Y-%m-%d_%H-%M-%S" pattern, the following @command{ffmpeg} command
832 ffmpeg -f v4l2 -r 1 -i /dev/video0 -f image2 -strftime 1 "%Y-%m-%d_%H-%M-%S.jpg"
839 Start the sequence from the specified number. Default value is 1.
842 If set to 1, the filename will always be interpreted as just a
843 filename, not a pattern, and the corresponding file will be continuously
844 overwritten with new images. Default value is 0.
847 If set to 1, expand the filename with date and time information from
848 @code{strftime()}. Default value is 0.
851 The image muxer supports the .Y.U.V image file format. This format is
852 special in that that each image frame consists of three files, for
853 each of the YUV420P components. To read or write this image file format,
854 specify the name of the '.Y' file. The muxer will automatically open the
855 '.U' and '.V' files as required.
859 Matroska container muxer.
861 This muxer implements the matroska and webm container specs.
865 The recognized metadata settings in this muxer are:
869 Set title name provided to a single track.
872 Specify the language of the track in the Matroska languages form.
874 The language can be either the 3 letters bibliographic ISO-639-2 (ISO
875 639-2/B) form (like "fre" for French), or a language code mixed with a
876 country code for specialities in languages (like "fre-ca" for Canadian
880 Set stereo 3D video layout of two views in a single video track.
882 The following values are recognized:
887 Both views are arranged side by side, Left-eye view is on the left
889 Both views are arranged in top-bottom orientation, Left-eye view is at bottom
891 Both views are arranged in top-bottom orientation, Left-eye view is on top
892 @item checkerboard_rl
893 Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first
894 @item checkerboard_lr
895 Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first
896 @item row_interleaved_rl
897 Each view is constituted by a row based interleaving, Right-eye view is first row
898 @item row_interleaved_lr
899 Each view is constituted by a row based interleaving, Left-eye view is first row
900 @item col_interleaved_rl
901 Both views are arranged in a column based interleaving manner, Right-eye view is first column
902 @item col_interleaved_lr
903 Both views are arranged in a column based interleaving manner, Left-eye view is first column
904 @item anaglyph_cyan_red
905 All frames are in anaglyph format viewable through red-cyan filters
907 Both views are arranged side by side, Right-eye view is on the left
908 @item anaglyph_green_magenta
909 All frames are in anaglyph format viewable through green-magenta filters
911 Both eyes laced in one Block, Left-eye view is first
913 Both eyes laced in one Block, Right-eye view is first
917 For example a 3D WebM clip can be created using the following command line:
919 ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm
924 This muxer supports the following options:
927 @item reserve_index_space
928 By default, this muxer writes the index for seeking (called cues in Matroska
929 terms) at the end of the file, because it cannot know in advance how much space
930 to leave for the index at the beginning of the file. However for some use cases
931 -- e.g. streaming where seeking is possible but slow -- it is useful to put the
932 index at the beginning of the file.
934 If this option is set to a non-zero value, the muxer will reserve a given amount
935 of space in the file header and then try to write the cues there when the muxing
936 finishes. If the available space does not suffice, muxing will fail. A safe size
937 for most use cases should be about 50kB per hour of video.
939 Note that cues are only written if the output is seekable and this option will
940 have no effect if it is not.
948 This is a variant of the @ref{hash} muxer. Unlike that muxer, it
949 defaults to using the MD5 hash function.
953 To compute the MD5 hash of the input converted to raw
954 audio and video, and store it in the file @file{out.md5}:
956 ffmpeg -i INPUT -f md5 out.md5
959 You can print the MD5 to stdout with the command:
961 ffmpeg -i INPUT -f md5 -
964 See also the @ref{hash} and @ref{framemd5} muxers.
966 @section mov, mp4, ismv
968 MOV/MP4/ISMV (Smooth Streaming) muxer.
970 The mov/mp4/ismv muxer supports fragmentation. Normally, a MOV/MP4
971 file has all the metadata about all packets stored in one location
972 (written at the end of the file, it can be moved to the start for
973 better playback by adding @var{faststart} to the @var{movflags}, or
974 using the @command{qt-faststart} tool). A fragmented
975 file consists of a number of fragments, where packets and metadata
976 about these packets are stored together. Writing a fragmented
977 file has the advantage that the file is decodable even if the
978 writing is interrupted (while a normal MOV/MP4 is undecodable if
979 it is not properly finished), and it requires less memory when writing
980 very long files (since writing normal MOV/MP4 files stores info about
981 every single packet in memory until the file is closed). The downside
982 is that it is less compatible with other applications.
986 Fragmentation is enabled by setting one of the AVOptions that define
987 how to cut the file into fragments:
990 @item -moov_size @var{bytes}
991 Reserves space for the moov atom at the beginning of the file instead of placing the
992 moov atom at the end. If the space reserved is insufficient, muxing will fail.
993 @item -movflags frag_keyframe
994 Start a new fragment at each video keyframe.
995 @item -frag_duration @var{duration}
996 Create fragments that are @var{duration} microseconds long.
997 @item -frag_size @var{size}
998 Create fragments that contain up to @var{size} bytes of payload data.
999 @item -movflags frag_custom
1000 Allow the caller to manually choose when to cut fragments, by
1001 calling @code{av_write_frame(ctx, NULL)} to write a fragment with
1002 the packets written so far. (This is only useful with other
1003 applications integrating libavformat, not from @command{ffmpeg}.)
1004 @item -min_frag_duration @var{duration}
1005 Don't create fragments that are shorter than @var{duration} microseconds long.
1008 If more than one condition is specified, fragments are cut when
1009 one of the specified conditions is fulfilled. The exception to this is
1010 @code{-min_frag_duration}, which has to be fulfilled for any of the other
1011 conditions to apply.
1013 Additionally, the way the output file is written can be adjusted
1014 through a few other options:
1017 @item -movflags empty_moov
1018 Write an initial moov atom directly at the start of the file, without
1019 describing any samples in it. Generally, an mdat/moov pair is written
1020 at the start of the file, as a normal MOV/MP4 file, containing only
1021 a short portion of the file. With this option set, there is no initial
1022 mdat atom, and the moov atom only describes the tracks but has
1025 This option is implicitly set when writing ismv (Smooth Streaming) files.
1026 @item -movflags separate_moof
1027 Write a separate moof (movie fragment) atom for each track. Normally,
1028 packets for all tracks are written in a moof atom (which is slightly
1029 more efficient), but with this option set, the muxer writes one moof/mdat
1030 pair for each track, making it easier to separate tracks.
1032 This option is implicitly set when writing ismv (Smooth Streaming) files.
1033 @item -movflags faststart
1034 Run a second pass moving the index (moov atom) to the beginning of the file.
1035 This operation can take a while, and will not work in various situations such
1036 as fragmented output, thus it is not enabled by default.
1037 @item -movflags rtphint
1038 Add RTP hinting tracks to the output file.
1039 @item -movflags disable_chpl
1040 Disable Nero chapter markers (chpl atom). Normally, both Nero chapters
1041 and a QuickTime chapter track are written to the file. With this option
1042 set, only the QuickTime chapter track will be written. Nero chapters can
1043 cause failures when the file is reprocessed with certain tagging programs, like
1044 mp3Tag 2.61a and iTunes 11.3, most likely other versions are affected as well.
1045 @item -movflags omit_tfhd_offset
1046 Do not write any absolute base_data_offset in tfhd atoms. This avoids
1047 tying fragments to absolute byte positions in the file/streams.
1048 @item -movflags default_base_moof
1049 Similarly to the omit_tfhd_offset, this flag avoids writing the
1050 absolute base_data_offset field in tfhd atoms, but does so by using
1051 the new default-base-is-moof flag instead. This flag is new from
1052 14496-12:2012. This may make the fragments easier to parse in certain
1053 circumstances (avoiding basing track fragment location calculations
1054 on the implicit end of the previous track fragment).
1056 Specify @code{on} to force writing a timecode track, @code{off} to disable it
1057 and @code{auto} to write a timecode track only for mov and mp4 output (default).
1062 Smooth Streaming content can be pushed in real time to a publishing
1063 point on IIS with this muxer. Example:
1065 ffmpeg -re @var{<normal input/transcoding options>} -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1)
1068 @subsection Audible AAX
1070 Audible AAX files are encrypted M4B files, and they can be decrypted by specifying a 4 byte activation secret.
1072 ffmpeg -activation_bytes 1CEB00DA -i test.aax -vn -c:a copy output.mp4
1077 The MP3 muxer writes a raw MP3 stream with the following optional features:
1080 An ID3v2 metadata header at the beginning (enabled by default). Versions 2.3 and
1081 2.4 are supported, the @code{id3v2_version} private option controls which one is
1082 used (3 or 4). Setting @code{id3v2_version} to 0 disables the ID3v2 header
1085 The muxer supports writing attached pictures (APIC frames) to the ID3v2 header.
1086 The pictures are supplied to the muxer in form of a video stream with a single
1087 packet. There can be any number of those streams, each will correspond to a
1088 single APIC frame. The stream metadata tags @var{title} and @var{comment} map
1089 to APIC @var{description} and @var{picture type} respectively. See
1090 @url{http://id3.org/id3v2.4.0-frames} for allowed picture types.
1092 Note that the APIC frames must be written at the beginning, so the muxer will
1093 buffer the audio frames until it gets all the pictures. It is therefore advised
1094 to provide the pictures as soon as possible to avoid excessive buffering.
1097 A Xing/LAME frame right after the ID3v2 header (if present). It is enabled by
1098 default, but will be written only if the output is seekable. The
1099 @code{write_xing} private option can be used to disable it. The frame contains
1100 various information that may be useful to the decoder, like the audio duration
1104 A legacy ID3v1 tag at the end of the file (disabled by default). It may be
1105 enabled with the @code{write_id3v1} private option, but as its capabilities are
1106 very limited, its usage is not recommended.
1111 Write an mp3 with an ID3v2.3 header and an ID3v1 footer:
1113 ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3
1116 To attach a picture to an mp3 file select both the audio and the picture stream
1119 ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1
1120 -metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3
1123 Write a "clean" MP3 without any extra features:
1125 ffmpeg -i input.wav -write_xing 0 -id3v2_version 0 out.mp3
1130 MPEG transport stream muxer.
1132 This muxer implements ISO 13818-1 and part of ETSI EN 300 468.
1134 The recognized metadata settings in mpegts muxer are @code{service_provider}
1135 and @code{service_name}. If they are not set the default for
1136 @code{service_provider} is @samp{FFmpeg} and the default for
1137 @code{service_name} is @samp{Service01}.
1141 The muxer options are:
1144 @item mpegts_transport_stream_id @var{integer}
1145 Set the @samp{transport_stream_id}. This identifies a transponder in DVB.
1146 Default is @code{0x0001}.
1148 @item mpegts_original_network_id @var{integer}
1149 Set the @samp{original_network_id}. This is unique identifier of a
1150 network in DVB. Its main use is in the unique identification of a service
1151 through the path @samp{Original_Network_ID, Transport_Stream_ID}. Default
1154 @item mpegts_service_id @var{integer}
1155 Set the @samp{service_id}, also known as program in DVB. Default is
1158 @item mpegts_service_type @var{integer}
1159 Set the program @samp{service_type}. Default is @code{digital_tv}.
1160 Accepts the following options:
1163 Any hexdecimal value between @code{0x01} to @code{0xff} as defined in
1168 Digital Radio service.
1171 @item advanced_codec_digital_radio
1172 Advanced Codec Digital Radio service.
1173 @item mpeg2_digital_hdtv
1174 MPEG2 Digital HDTV service.
1175 @item advanced_codec_digital_sdtv
1176 Advanced Codec Digital SDTV service.
1177 @item advanced_codec_digital_hdtv
1178 Advanced Codec Digital HDTV service.
1181 @item mpegts_pmt_start_pid @var{integer}
1182 Set the first PID for PMT. Default is @code{0x1000}. Max is @code{0x1f00}.
1184 @item mpegts_start_pid @var{integer}
1185 Set the first PID for data packets. Default is @code{0x0100}. Max is
1188 @item mpegts_m2ts_mode @var{boolean}
1189 Enable m2ts mode if set to @code{1}. Default value is @code{-1} which
1192 @item muxrate @var{integer}
1193 Set a constant muxrate. Default is VBR.
1195 @item pes_payload_size @var{integer}
1196 Set minimum PES packet payload in bytes. Default is @code{2930}.
1198 @item mpegts_flags @var{flags}
1199 Set mpegts flags. Accepts the following options:
1201 @item resend_headers
1202 Reemit PAT/PMT before writing the next packet.
1204 Use LATM packetization for AAC.
1205 @item pat_pmt_at_frames
1206 Reemit PAT and PMT at each video frame.
1208 Conform to System B (DVB) instead of System A (ATSC).
1209 @item initial_discontinuity
1210 Mark the initial packet of each stream as discontinuity.
1213 @item resend_headers @var{integer}
1214 Reemit PAT/PMT before writing the next packet. This option is deprecated:
1215 use @option{mpegts_flags} instead.
1217 @item mpegts_copyts @var{boolean}
1218 Preserve original timestamps, if value is set to @code{1}. Default value
1219 is @code{-1}, which results in shifting timestamps so that they start from 0.
1221 @item omit_video_pes_length @var{boolean}
1222 Omit the PES packet length for video packets. Default is @code{1} (true).
1224 @item pcr_period @var{integer}
1225 Override the default PCR retransmission time in milliseconds. Ignored if
1226 variable muxrate is selected. Default is @code{20}.
1228 @item pat_period @var{double}
1229 Maximum time in seconds between PAT/PMT tables.
1231 @item sdt_period @var{double}
1232 Maximum time in seconds between SDT tables.
1234 @item tables_version @var{integer}
1235 Set PAT, PMT and SDT version (default @code{0}, valid values are from 0 to 31, inclusively).
1236 This option allows updating stream structure so that standard consumer may
1237 detect the change. To do so, reopen output @code{AVFormatContext} (in case of API
1238 usage) or restart @command{ffmpeg} instance, cyclically changing
1239 @option{tables_version} value:
1242 ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
1243 ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
1245 ffmpeg -i source3.ts -codec copy -f mpegts -tables_version 31 udp://1.1.1.1:1111
1246 ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
1247 ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
1255 ffmpeg -i file.mpg -c copy \
1256 -mpegts_original_network_id 0x1122 \
1257 -mpegts_transport_stream_id 0x3344 \
1258 -mpegts_service_id 0x5566 \
1259 -mpegts_pmt_start_pid 0x1500 \
1260 -mpegts_start_pid 0x150 \
1261 -metadata service_provider="Some provider" \
1262 -metadata service_name="Some Channel" \
1266 @section mxf, mxf_d10
1272 The muxer options are:
1275 @item store_user_comments @var{bool}
1276 Set if user comments should be stored if available or never.
1277 IRT D-10 does not allow user comments. The default is thus to write them for
1278 mxf but not for mxf_d10
1285 This muxer does not generate any output file, it is mainly useful for
1286 testing or benchmarking purposes.
1288 For example to benchmark decoding with @command{ffmpeg} you can use the
1291 ffmpeg -benchmark -i INPUT -f null out.null
1294 Note that the above command does not read or write the @file{out.null}
1295 file, but specifying the output file is required by the @command{ffmpeg}
1298 Alternatively you can write the command as:
1300 ffmpeg -benchmark -i INPUT -f null -
1306 @item -syncpoints @var{flags}
1307 Change the syncpoint usage in nut:
1309 @item @var{default} use the normal low-overhead seeking aids.
1310 @item @var{none} do not use the syncpoints at all, reducing the overhead but making the stream non-seekable;
1311 Use of this option is not recommended, as the resulting files are very damage
1312 sensitive and seeking is not possible. Also in general the overhead from
1313 syncpoints is negligible. Note, -@code{write_index} 0 can be used to disable
1314 all growing data tables, allowing to mux endless streams with limited memory
1315 and without these disadvantages.
1316 @item @var{timestamped} extend the syncpoint with a wallclock field.
1318 The @var{none} and @var{timestamped} flags are experimental.
1319 @item -write_index @var{bool}
1320 Write index at the end, the default is to write an index.
1324 ffmpeg -i INPUT -f_strict experimental -syncpoints none - | processor
1329 Ogg container muxer.
1332 @item -page_duration @var{duration}
1333 Preferred page duration, in microseconds. The muxer will attempt to create
1334 pages that are approximately @var{duration} microseconds long. This allows the
1335 user to compromise between seek granularity and container overhead. The default
1336 is 1 second. A value of 0 will fill all segments, making pages as large as
1337 possible. A value of 1 will effectively use 1 packet-per-page in most
1338 situations, giving a small seek granularity at the cost of additional container
1340 @item -serial_offset @var{value}
1341 Serial value from which to set the streams serial number.
1342 Setting it to different and sufficiently large values ensures that the produced
1343 ogg files can be safely chained.
1348 @section segment, stream_segment, ssegment
1350 Basic stream segmenter.
1352 This muxer outputs streams to a number of separate files of nearly
1353 fixed duration. Output filename pattern can be set in a fashion
1354 similar to @ref{image2}, or by using a @code{strftime} template if
1355 the @option{strftime} option is enabled.
1357 @code{stream_segment} is a variant of the muxer used to write to
1358 streaming output formats, i.e. which do not require global headers,
1359 and is recommended for outputting e.g. to MPEG transport stream segments.
1360 @code{ssegment} is a shorter alias for @code{stream_segment}.
1362 Every segment starts with a keyframe of the selected reference stream,
1363 which is set through the @option{reference_stream} option.
1365 Note that if you want accurate splitting for a video file, you need to
1366 make the input key frames correspond to the exact splitting times
1367 expected by the segmenter, or the segment muxer will start the new
1368 segment with the key frame found next after the specified start
1371 The segment muxer works best with a single constant frame rate video.
1373 Optionally it can generate a list of the created segments, by setting
1374 the option @var{segment_list}. The list type is specified by the
1375 @var{segment_list_type} option. The entry filenames in the segment
1376 list are set by default to the basename of the corresponding segment
1379 See also the @ref{hls} muxer, which provides a more specific
1380 implementation for HLS segmentation.
1384 The segment muxer supports the following options:
1387 @item increment_tc @var{1|0}
1388 if set to @code{1}, increment timecode between each segment
1389 If this is selected, the input need to have
1390 a timecode in the first video stream. Default value is
1393 @item reference_stream @var{specifier}
1394 Set the reference stream, as specified by the string @var{specifier}.
1395 If @var{specifier} is set to @code{auto}, the reference is chosen
1396 automatically. Otherwise it must be a stream specifier (see the ``Stream
1397 specifiers'' chapter in the ffmpeg manual) which specifies the
1398 reference stream. The default value is @code{auto}.
1400 @item segment_format @var{format}
1401 Override the inner container format, by default it is guessed by the filename
1404 @item segment_format_options @var{options_list}
1405 Set output format options using a :-separated list of key=value
1406 parameters. Values containing the @code{:} special character must be
1409 @item segment_list @var{name}
1410 Generate also a listfile named @var{name}. If not specified no
1411 listfile is generated.
1413 @item segment_list_flags @var{flags}
1414 Set flags affecting the segment list generation.
1416 It currently supports the following flags:
1419 Allow caching (only affects M3U8 list files).
1422 Allow live-friendly file generation.
1425 @item segment_list_size @var{size}
1426 Update the list file so that it contains at most @var{size}
1427 segments. If 0 the list file will contain all the segments. Default
1430 @item segment_list_entry_prefix @var{prefix}
1431 Prepend @var{prefix} to each entry. Useful to generate absolute paths.
1432 By default no prefix is applied.
1434 @item segment_list_type @var{type}
1435 Select the listing format.
1437 The following values are recognized:
1440 Generate a flat list for the created segments, one segment per line.
1443 Generate a list for the created segments, one segment per line,
1444 each line matching the format (comma-separated values):
1446 @var{segment_filename},@var{segment_start_time},@var{segment_end_time}
1449 @var{segment_filename} is the name of the output file generated by the
1450 muxer according to the provided pattern. CSV escaping (according to
1451 RFC4180) is applied if required.
1453 @var{segment_start_time} and @var{segment_end_time} specify
1454 the segment start and end time expressed in seconds.
1456 A list file with the suffix @code{".csv"} or @code{".ext"} will
1457 auto-select this format.
1459 @samp{ext} is deprecated in favor or @samp{csv}.
1462 Generate an ffconcat file for the created segments. The resulting file
1463 can be read using the FFmpeg @ref{concat} demuxer.
1465 A list file with the suffix @code{".ffcat"} or @code{".ffconcat"} will
1466 auto-select this format.
1469 Generate an extended M3U8 file, version 3, compliant with
1470 @url{http://tools.ietf.org/id/draft-pantos-http-live-streaming}.
1472 A list file with the suffix @code{".m3u8"} will auto-select this format.
1475 If not specified the type is guessed from the list file name suffix.
1477 @item segment_time @var{time}
1478 Set segment duration to @var{time}, the value must be a duration
1479 specification. Default value is "2". See also the
1480 @option{segment_times} option.
1482 Note that splitting may not be accurate, unless you force the
1483 reference stream key-frames at the given time. See the introductory
1484 notice and the examples below.
1486 @item segment_atclocktime @var{1|0}
1487 If set to "1" split at regular clock time intervals starting from 00:00
1488 o'clock. The @var{time} value specified in @option{segment_time} is
1489 used for setting the length of the splitting interval.
1491 For example with @option{segment_time} set to "900" this makes it possible
1492 to create files at 12:00 o'clock, 12:15, 12:30, etc.
1494 Default value is "0".
1496 @item segment_clocktime_offset @var{duration}
1497 Delay the segment splitting times with the specified duration when using
1498 @option{segment_atclocktime}.
1500 For example with @option{segment_time} set to "900" and
1501 @option{segment_clocktime_offset} set to "300" this makes it possible to
1502 create files at 12:05, 12:20, 12:35, etc.
1504 Default value is "0".
1506 @item segment_clocktime_wrap_duration @var{duration}
1507 Force the segmenter to only start a new segment if a packet reaches the muxer
1508 within the specified duration after the segmenting clock time. This way you
1509 can make the segmenter more resilient to backward local time jumps, such as
1510 leap seconds or transition to standard time from daylight savings time.
1512 Default is the maximum possible duration which means starting a new segment
1513 regardless of the elapsed time since the last clock time.
1515 @item segment_time_delta @var{delta}
1516 Specify the accuracy time when selecting the start time for a
1517 segment, expressed as a duration specification. Default value is "0".
1519 When delta is specified a key-frame will start a new segment if its
1520 PTS satisfies the relation:
1522 PTS >= start_time - time_delta
1525 This option is useful when splitting video content, which is always
1526 split at GOP boundaries, in case a key frame is found just before the
1527 specified split time.
1529 In particular may be used in combination with the @file{ffmpeg} option
1530 @var{force_key_frames}. The key frame times specified by
1531 @var{force_key_frames} may not be set accurately because of rounding
1532 issues, with the consequence that a key frame time may result set just
1533 before the specified time. For constant frame rate videos a value of
1534 1/(2*@var{frame_rate}) should address the worst case mismatch between
1535 the specified time and the time set by @var{force_key_frames}.
1537 @item segment_times @var{times}
1538 Specify a list of split points. @var{times} contains a list of comma
1539 separated duration specifications, in increasing order. See also
1540 the @option{segment_time} option.
1542 @item segment_frames @var{frames}
1543 Specify a list of split video frame numbers. @var{frames} contains a
1544 list of comma separated integer numbers, in increasing order.
1546 This option specifies to start a new segment whenever a reference
1547 stream key frame is found and the sequential number (starting from 0)
1548 of the frame is greater or equal to the next value in the list.
1550 @item segment_wrap @var{limit}
1551 Wrap around segment index once it reaches @var{limit}.
1553 @item segment_start_number @var{number}
1554 Set the sequence number of the first segment. Defaults to @code{0}.
1556 @item strftime @var{1|0}
1557 Use the @code{strftime} function to define the name of the new
1558 segments to write. If this is selected, the output segment name must
1559 contain a @code{strftime} function template. Default value is
1562 @item break_non_keyframes @var{1|0}
1563 If enabled, allow segments to start on frames other than keyframes. This
1564 improves behavior on some players when the time between keyframes is
1565 inconsistent, but may make things worse on others, and can cause some oddities
1566 during seeking. Defaults to @code{0}.
1568 @item reset_timestamps @var{1|0}
1569 Reset timestamps at the beginning of each segment, so that each segment
1570 will start with near-zero timestamps. It is meant to ease the playback
1571 of the generated segments. May not work with some combinations of
1572 muxers/codecs. It is set to @code{0} by default.
1574 @item initial_offset @var{offset}
1575 Specify timestamp offset to apply to the output packet timestamps. The
1576 argument must be a time duration specification, and defaults to 0.
1578 @item write_empty_segments @var{1|0}
1579 If enabled, write an empty segment if there are no packets during the period a
1580 segment would usually span. Otherwise, the segment will be filled with the next
1581 packet written. Defaults to @code{0}.
1584 @subsection Examples
1588 Remux the content of file @file{in.mkv} to a list of segments
1589 @file{out-000.nut}, @file{out-001.nut}, etc., and write the list of
1590 generated segments to @file{out.list}:
1592 ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.list out%03d.nut
1596 Segment input and set output format options for the output segments:
1598 ffmpeg -i in.mkv -f segment -segment_time 10 -segment_format_options movflags=+faststart out%03d.mp4
1602 Segment the input file according to the split points specified by the
1603 @var{segment_times} option:
1605 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
1609 Use the @command{ffmpeg} @option{force_key_frames}
1610 option to force key frames in the input at the specified location, together
1611 with the segment option @option{segment_time_delta} to account for
1612 possible roundings operated when setting key frame times.
1614 ffmpeg -i in.mkv -force_key_frames 1,2,3,5,8,13,21 -codec:v mpeg4 -codec:a pcm_s16le -map 0 \
1615 -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 -segment_time_delta 0.05 out%03d.nut
1617 In order to force key frames on the input file, transcoding is
1621 Segment the input file by splitting the input file according to the
1622 frame numbers sequence specified with the @option{segment_frames} option:
1624 ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_frames 100,200,300,500,800 out%03d.nut
1628 Convert the @file{in.mkv} to TS segments using the @code{libx264}
1629 and @code{aac} encoders:
1631 ffmpeg -i in.mkv -map 0 -codec:v libx264 -codec:a aac -f ssegment -segment_list out.list out%03d.ts
1635 Segment the input file, and create an M3U8 live playlist (can be used
1636 as live HLS source):
1638 ffmpeg -re -i in.mkv -codec copy -map 0 -f segment -segment_list playlist.m3u8 \
1639 -segment_list_flags +live -segment_time 10 out%03d.mkv
1643 @section smoothstreaming
1645 Smooth Streaming muxer generates a set of files (Manifest, chunks) suitable for serving with conventional web server.
1649 Specify the number of fragments kept in the manifest. Default 0 (keep all).
1651 @item extra_window_size
1652 Specify the number of fragments kept outside of the manifest before removing from disk. Default 5.
1654 @item lookahead_count
1655 Specify the number of lookahead fragments. Default 2.
1657 @item min_frag_duration
1658 Specify the minimum fragment duration (in microseconds). Default 5000000.
1660 @item remove_at_exit
1661 Specify whether to remove all fragments when finished. Default 0 (do not remove).
1668 The fifo pseudo-muxer allows the separation of encoding and muxing by using
1669 first-in-first-out queue and running the actual muxer in a separate thread. This
1670 is especially useful in combination with the @ref{tee} muxer and can be used to
1671 send data to several destinations with different reliability/writing speed/latency.
1673 API users should be aware that callback functions (interrupt_callback,
1674 io_open and io_close) used within its AVFormatContext must be thread-safe.
1676 The behavior of the fifo muxer if the queue fills up or if the output fails is
1682 output can be transparently restarted with configurable delay between retries
1683 based on real time or time of the processed stream.
1686 encoding can be blocked during temporary failure, or continue transparently
1687 dropping packets in case fifo queue fills up.
1694 Specify the format name. Useful if it cannot be guessed from the
1698 Specify size of the queue (number of packets). Default value is 60.
1701 Specify format options for the underlying muxer. Muxer options can be specified
1702 as a list of @var{key}=@var{value} pairs separated by ':'.
1704 @item drop_pkts_on_overflow @var{bool}
1705 If set to 1 (true), in case the fifo queue fills up, packets will be dropped
1706 rather than blocking the encoder. This makes it possible to continue streaming without
1707 delaying the input, at the cost of omitting part of the stream. By default
1708 this option is set to 0 (false), so in such cases the encoder will be blocked
1709 until the muxer processes some of the packets and none of them is lost.
1711 @item attempt_recovery @var{bool}
1712 If failure occurs, attempt to recover the output. This is especially useful
1713 when used with network output, since it makes it possible to restart streaming transparently.
1714 By default this option is set to 0 (false).
1716 @item max_recovery_attempts
1717 Sets maximum number of successive unsuccessful recovery attempts after which
1718 the output fails permanently. By default this option is set to 0 (unlimited).
1720 @item recovery_wait_time @var{duration}
1721 Waiting time before the next recovery attempt after previous unsuccessful
1722 recovery attempt. Default value is 5 seconds.
1724 @item recovery_wait_streamtime @var{bool}
1725 If set to 0 (false), the real time is used when waiting for the recovery
1726 attempt (i.e. the recovery will be attempted after at least
1727 recovery_wait_time seconds).
1728 If set to 1 (true), the time of the processed stream is taken into account
1729 instead (i.e. the recovery will be attempted after at least @var{recovery_wait_time}
1730 seconds of the stream is omitted).
1731 By default, this option is set to 0 (false).
1733 @item recover_any_error @var{bool}
1734 If set to 1 (true), recovery will be attempted regardless of type of the error
1735 causing the failure. By default this option is set to 0 (false) and in case of
1736 certain (usually permanent) errors the recovery is not attempted even when
1737 @var{attempt_recovery} is set to 1.
1739 @item restart_with_keyframe @var{bool}
1740 Specify whether to wait for the keyframe after recovering from
1741 queue overflow or failure. This option is set to 0 (false) by default.
1745 @subsection Examples
1750 Stream something to rtmp server, continue processing the stream at real-time
1751 rate even in case of temporary failure (network outage) and attempt to recover
1752 streaming every second indefinitely.
1754 ffmpeg -re -i ... -c:v libx264 -c:a aac -f fifo -fifo_format flv -map 0:v -map 0:a
1755 -drop_pkts_on_overflow 1 -attempt_recovery 1 -recovery_wait_time 1 rtmp://example.com/live/stream_name
1763 The tee muxer can be used to write the same data to several files or any
1764 other kind of muxer. It can be used, for example, to both stream a video to
1765 the network and save it to disk at the same time.
1767 It is different from specifying several outputs to the @command{ffmpeg}
1768 command-line tool because the audio and video data will be encoded only once
1769 with the tee muxer; encoding can be a very expensive process. It is not
1770 useful when using the libavformat API directly because it is then possible
1771 to feed the same packets to several muxers directly.
1775 @item use_fifo @var{bool}
1776 If set to 1, slave outputs will be processed in separate thread using @ref{fifo}
1777 muxer. This allows to compensate for different speed/latency/reliability of
1778 outputs and setup transparent recovery. By default this feature is turned off.
1781 Options to pass to fifo pseudo-muxer instances. See @ref{fifo}.
1785 The slave outputs are specified in the file name given to the muxer,
1786 separated by '|'. If any of the slave name contains the '|' separator,
1787 leading or trailing spaces or any special character, it must be
1788 escaped (see @ref{quoting_and_escaping,,the "Quoting and escaping"
1789 section in the ffmpeg-utils(1) manual,ffmpeg-utils}).
1791 Muxer options can be specified for each slave by prepending them as a list of
1792 @var{key}=@var{value} pairs separated by ':', between square brackets. If
1793 the options values contain a special character or the ':' separator, they
1794 must be escaped; note that this is a second level escaping.
1796 The following special options are also recognized:
1799 Specify the format name. Useful if it cannot be guessed from the
1802 @item bsfs[/@var{spec}]
1803 Specify a list of bitstream filters to apply to the specified
1806 @item use_fifo @var{bool}
1807 This allows to override tee muxer use_fifo option for individual slave muxer.
1810 This allows to override tee muxer fifo_options for individual slave muxer.
1813 It is possible to specify to which streams a given bitstream filter
1814 applies, by appending a stream specifier to the option separated by
1815 @code{/}. @var{spec} must be a stream specifier (see @ref{Format
1816 stream specifiers}). If the stream specifier is not specified, the
1817 bitstream filters will be applied to all streams in the output.
1819 Several bitstream filters can be specified, separated by ",".
1822 Select the streams that should be mapped to the slave output,
1823 specified by a stream specifier. If not specified, this defaults to
1824 all the input streams. You may use multiple stream specifiers
1825 separated by commas (@code{,}) e.g.: @code{a:0,v}
1828 Specify behaviour on output failure. This can be set to either @code{abort} (which is
1829 default) or @code{ignore}. @code{abort} will cause whole process to fail in case of failure
1830 on this slave output. @code{ignore} will ignore failure on this output, so other outputs
1831 will continue without being affected.
1834 @subsection Examples
1838 Encode something and both archive it in a WebM file and stream it
1839 as MPEG-TS over UDP (the streams need to be explicitly mapped):
1841 ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
1842 "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
1846 As above, but continue streaming even if output to local file fails
1847 (for example local drive fills up):
1849 ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
1850 "[onfail=ignore]archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
1854 Use @command{ffmpeg} to encode the input, and send the output
1855 to three different destinations. The @code{dump_extra} bitstream
1856 filter is used to add extradata information to all the output video
1857 keyframes packets, as requested by the MPEG-TS format. The select
1858 option is applied to @file{out.aac} in order to make it contain only
1861 ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
1862 -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac"
1866 As below, but select only stream @code{a:1} for the audio output. Note
1867 that a second level escaping must be performed, as ":" is a special
1868 character used to separate options.
1870 ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
1871 -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=\'a:1\']out.aac"
1875 Note: some codecs may need different options depending on the output format;
1876 the auto-detection of this can not work with the tee muxer. The main example
1877 is the @option{global_header} flag.
1879 @section webm_dash_manifest
1881 WebM DASH Manifest muxer.
1883 This muxer implements the WebM DASH Manifest specification to generate the DASH
1884 manifest XML. It also supports manifest generation for DASH live streams.
1886 For more information see:
1890 WebM DASH Specification: @url{https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification}
1892 ISO DASH Specification: @url{http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip}
1897 This muxer supports the following options:
1900 @item adaptation_sets
1901 This option has the following syntax: "id=x,streams=a,b,c id=y,streams=d,e" where x and y are the
1902 unique identifiers of the adaptation sets and a,b,c,d and e are the indices of the corresponding
1903 audio and video streams. Any number of adaptation sets can be added using this option.
1906 Set this to 1 to create a live stream DASH Manifest. Default: 0.
1908 @item chunk_start_index
1909 Start index of the first chunk. This will go in the @samp{startNumber} attribute
1910 of the @samp{SegmentTemplate} element in the manifest. Default: 0.
1912 @item chunk_duration_ms
1913 Duration of each chunk in milliseconds. This will go in the @samp{duration}
1914 attribute of the @samp{SegmentTemplate} element in the manifest. Default: 1000.
1916 @item utc_timing_url
1917 URL of the page that will return the UTC timestamp in ISO format. This will go
1918 in the @samp{value} attribute of the @samp{UTCTiming} element in the manifest.
1921 @item time_shift_buffer_depth
1922 Smallest time (in seconds) shifting buffer for which any Representation is
1923 guaranteed to be available. This will go in the @samp{timeShiftBufferDepth}
1924 attribute of the @samp{MPD} element. Default: 60.
1926 @item minimum_update_period
1927 Minimum update period (in seconds) of the manifest. This will go in the
1928 @samp{minimumUpdatePeriod} attribute of the @samp{MPD} element. Default: 0.
1934 ffmpeg -f webm_dash_manifest -i video1.webm \
1935 -f webm_dash_manifest -i video2.webm \
1936 -f webm_dash_manifest -i audio1.webm \
1937 -f webm_dash_manifest -i audio2.webm \
1938 -map 0 -map 1 -map 2 -map 3 \
1940 -f webm_dash_manifest \
1941 -adaptation_sets "id=0,streams=0,1 id=1,streams=2,3" \
1947 WebM Live Chunk Muxer.
1949 This muxer writes out WebM headers and chunks as separate files which can be
1950 consumed by clients that support WebM Live streams via DASH.
1954 This muxer supports the following options:
1957 @item chunk_start_index
1958 Index of the first chunk (defaults to 0).
1961 Filename of the header where the initialization data will be written.
1963 @item audio_chunk_duration
1964 Duration of each audio chunk in milliseconds (defaults to 5000).
1969 ffmpeg -f v4l2 -i /dev/video0 \
1973 -s 640x360 -keyint_min 30 -g 30 \
1975 -header webm_live_video_360.hdr \
1976 -chunk_start_index 1 \
1977 webm_live_video_360_%d.chk \
1982 -header webm_live_audio_128.hdr \
1983 -chunk_start_index 1 \
1984 -audio_chunk_duration 1000 \
1985 webm_live_audio_128_%d.chk