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,
100 which generates a fingerprint for the provided audio data. See @url{https://acoustid.org/chromaprint}
102 It takes a single signed native-endian 16-bit raw audio stream of at most 2 channels.
107 @item silence_threshold
108 Threshold for detecting silence. Range is from -1 to 32767, where -1 disables
109 silence detection. Silence detection can only be used with version 3 of the
111 Silence detection must be disabled for use with the AcoustID service. Default is -1.
114 Version of algorithm to fingerprint with. Range is 0 to 4.
115 Version 3 enables silence detection. Default is 1.
118 Format to output the fingerprint as. Accepts the following options:
121 Binary raw fingerprint
124 Binary compressed fingerprint
127 Base64 compressed fingerprint @emph{(default)}
136 CRC (Cyclic Redundancy Check) testing format.
138 This muxer computes and prints the Adler-32 CRC of all the input audio
139 and video frames. By default audio frames are converted to signed
140 16-bit raw audio and video frames to raw video before computing the
143 The output of the muxer consists of a single line of the form:
144 CRC=0x@var{CRC}, where @var{CRC} is a hexadecimal number 0-padded to
145 8 digits containing the CRC for all the decoded input frames.
147 See also the @ref{framecrc} muxer.
151 For example to compute the CRC of the input, and store it in the file
154 ffmpeg -i INPUT -f crc out.crc
157 You can print the CRC to stdout with the command:
159 ffmpeg -i INPUT -f crc -
162 You can select the output format of each frame with @command{ffmpeg} by
163 specifying the audio and video codec and format. For example to
164 compute the CRC of the input audio converted to PCM unsigned 8-bit
165 and the input video converted to MPEG-2 video, use the command:
167 ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc -
172 Adobe Flash Video Format muxer.
174 This muxer accepts the following options:
178 @item flvflags @var{flags}
183 @item aac_seq_header_detect
184 Place AAC sequence header based on audio stream data.
186 @item no_sequence_end
187 Disable sequence end tag.
190 Disable metadata tag.
192 @item no_duration_filesize
193 Disable duration and filesize in metadata when they are equal to zero
194 at the end of stream. (Be used to non-seekable living stream).
196 @item add_keyframe_index
197 Used to facilitate seeking; particularly for HTTP pseudo streaming.
204 Dynamic Adaptive Streaming over HTTP (DASH) muxer that creates segments
205 and manifest files according to the MPEG-DASH standard ISO/IEC 23009-1:2014.
207 For more information see:
211 ISO DASH Specification: @url{http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip}
213 WebM DASH Specification: @url{https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification}
216 It creates a MPD manifest file and segment files for each stream.
218 The segment filename might contain pre-defined identifiers used with SegmentTemplate
219 as defined in section 5.3.9.4.4 of the standard. Available identifiers are "$RepresentationID$",
220 "$Number$", "$Bandwidth$" and "$Time$".
221 In addition to the standard identifiers, an ffmpeg-specific "$ext$" identifier is also supported.
222 When specified ffmpeg will replace $ext$ in the file name with muxing format's extensions such as mp4, webm etc.,
225 ffmpeg -re -i <input> -map 0 -map 0 -c:a libfdk_aac -c:v libx264 \
226 -b:v:0 800k -b:v:1 300k -s:v:1 320x170 -profile:v:1 baseline \
227 -profile:v:0 main -bf 1 -keyint_min 120 -g 120 -sc_threshold 0 \
228 -b_strategy 0 -ar:a:1 22050 -use_timeline 1 -use_template 1 \
229 -window_size 5 -adaptation_sets "id=0,streams=v id=1,streams=a" \
230 -f dash /path/to/out.mpd
234 @item min_seg_duration @var{microseconds}
235 This is a deprecated option to set the segment length in microseconds, use @var{seg_duration} instead.
236 @item seg_duration @var{duration}
237 Set the segment length in seconds (fractional value can be set). The value is
238 treated as average segment duration when @var{use_template} is enabled and
239 @item frag_duration @var{duration}
240 Set the length in seconds of fragments within segments (fractional value can be set).
241 @item frag_type @var{type}
242 Set the type of interval for fragmentation.
243 @item window_size @var{size}
244 Set the maximum number of segments kept in the manifest.
245 @item extra_window_size @var{size}
246 Set the maximum number of segments kept outside of the manifest before removing from disk.
247 @item remove_at_exit @var{remove}
248 Enable (1) or disable (0) removal of all segments when finished.
249 @item use_template @var{template}
250 Enable (1) or disable (0) use of SegmentTemplate instead of SegmentList.
251 @item use_timeline @var{timeline}
252 Enable (1) or disable (0) use of SegmentTimeline in SegmentTemplate.
253 @item single_file @var{single_file}
254 Enable (1) or disable (0) storing all segments in one file, accessed using byte ranges.
255 @item single_file_name @var{file_name}
256 DASH-templated name to be used for baseURL. Implies @var{single_file} set to "1". In the template, "$ext$" is replaced with the file name extension specific for the segment format.
257 @item init_seg_name @var{init_name}
258 DASH-templated name to used for the initialization segment. Default is "init-stream$RepresentationID$.$ext$". "$ext$" is replaced with the file name extension specific for the segment format.
259 @item media_seg_name @var{segment_name}
260 DASH-templated name to used for the media segments. Default is "chunk-stream$RepresentationID$-$Number%05d$.$ext$". "$ext$" is replaced with the file name extension specific for the segment format.
261 @item utc_timing_url @var{utc_url}
262 URL of the page that will return the UTC timestamp in ISO format. Example: "https://time.akamai.com/?iso"
263 @item method @var{method}
264 Use the given HTTP method to create output files. Generally set to PUT or POST.
265 @item http_user_agent @var{user_agent}
266 Override User-Agent field in HTTP header. Applicable only for HTTP output.
267 @item http_persistent @var{http_persistent}
268 Use persistent HTTP connections. Applicable only for HTTP output.
269 @item hls_playlist @var{hls_playlist}
270 Generate HLS playlist files as well. The master playlist is generated with the filename @var{hls_master_name}.
271 One media playlist file is generated for each stream with filenames media_0.m3u8, media_1.m3u8, etc.
272 @item hls_master_name @var{file_name}
273 HLS master playlist name. Default is "master.m3u8".
274 @item streaming @var{streaming}
275 Enable (1) or disable (0) chunk streaming mode of output. In chunk streaming
276 mode, each frame will be a moof fragment which forms a chunk.
277 @item adaptation_sets @var{adaptation_sets}
278 Assign streams to AdaptationSets. Syntax is "id=x,streams=a,b,c id=y,streams=d,e" with x and y being the IDs
279 of the adaptation sets and a,b,c,d and e are the indices of the mapped streams.
281 To map all video (or audio) streams to an AdaptationSet, "v" (or "a") can be used as stream identifier instead of IDs.
283 When no assignment is defined, this defaults to an AdaptationSet for each stream.
285 Optional syntax is "id=x,seg_duration=x,frag_duration=x,frag_type=type,descriptor=descriptor_string,streams=a,b,c id=y,seg_duration=y,frag_type=type,streams=d,e" and so on,
286 descriptor is useful to the scheme defined by ISO/IEC 23009-1:2014/Amd.2:2015.
287 For example, -adaptation_sets "id=0,descriptor=<SupplementalProperty schemeIdUri=\"urn:mpeg:dash:srd:2014\" value=\"0,0,0,1,1,2,2\"/>,streams=v".
288 Please note that descriptor string should be a self-closing xml tag.
289 seg_duration, frag_duration and frag_type override the global option values for each adaptation set.
290 For example, -adaptation_sets "id=0,seg_duration=2,frag_duration=1,frag_type=duration,streams=v id=1,seg_duration=2,frag_type=none,streams=a"
291 type_id marks an adaptation set as containing streams meant to be used for Trick Mode for the referenced adaptation set.
292 For example, -adaptation_sets "id=0,seg_duration=2,frag_type=none,streams=0 id=1,seg_duration=10,frag_type=none,trick_id=0,streams=1"
293 @item timeout @var{timeout}
294 Set timeout for socket I/O operations. Applicable only for HTTP output.
295 @item index_correction @var{index_correction}
296 Enable (1) or Disable (0) segment index correction logic. Applicable only when
297 @var{use_template} is enabled and @var{use_timeline} is disabled.
299 When enabled, the logic monitors the flow of segment indexes. If a streams's
300 segment index value is not at the expected real time position, then the logic
301 corrects that index value.
303 Typically this logic is needed in live streaming use cases. The network bandwidth
304 fluctuations are common during long run streaming. Each fluctuation can cause
305 the segment indexes fall behind the expected real time position.
306 @item format_options @var{options_list}
307 Set container format (mp4/webm) options using a @code{:} separated list of
308 key=value parameters. Values containing @code{:} special characters must be
311 @item global_sidx @var{global_sidx}
312 Write global SIDX atom. Applicable only for single file, mp4 output, non-streaming mode.
314 @item dash_segment_type @var{dash_segment_type}
318 If this flag is set, the dash segment files format will be selected based on the stream codec. This is the default mode.
321 If this flag is set, the dash segment files will be in in ISOBMFF format.
324 If this flag is set, the dash segment files will be in in WebM format.
327 @item ignore_io_errors @var{ignore_io_errors}
328 Ignore IO errors during open and write. Useful for long-duration runs with network output.
330 @item lhls @var{lhls}
331 Enable Low-latency HLS(LHLS). Adds #EXT-X-PREFETCH tag with current segment's URI.
332 Apple doesn't have an official spec for LHLS. Meanwhile hls.js player folks are
333 trying to standardize a open LHLS spec. The draft spec is available in https://github.com/video-dev/hlsjs-rfcs/blob/lhls-spec/proposals/0001-lhls.md
334 This option will also try to comply with the above open spec, till Apple's spec officially supports it.
335 Applicable only when @var{streaming} and @var{hls_playlist} options are enabled.
336 This is an experimental feature.
338 @item ldash @var{ldash}
339 Enable Low-latency Dash by constraining the presence and values of some elements.
341 @item master_m3u8_publish_rate @var{master_m3u8_publish_rate}
342 Publish master playlist repeatedly every after specified number of segment intervals.
344 @item write_prft @var{write_prft}
345 Write Producer Reference Time elements on supported streams. This also enables writing
346 prft boxes in the underlying muxer. Applicable only when the @var{utc_url} option is enabled.
347 It's set to auto by default, in which case the muxer will attempt to enable it only in modes
350 @item mpd_profile @var{mpd_profile}
351 Set one or more manifest profiles.
353 @item http_opts @var{http_opts}
354 A :-separated list of key=value options to pass to the underlying HTTP
355 protocol. Applicable only for HTTP output.
357 @item target_latency @var{target_latency}
358 Set an intended target latency in seconds (fractional value can be set) for serving. Applicable only when @var{streaming} and @var{write_prft} options are enabled.
359 This is an informative fields clients can use to measure the latency of the service.
361 @item min_playback_rate @var{min_playback_rate}
362 Set the minimum playback rate indicated as appropriate for the purposes of automatically
363 adjusting playback latency and buffer occupancy during normal playback by clients.
365 @item max_playback_rate @var{max_playback_rate}
366 Set the maximum playback rate indicated as appropriate for the purposes of automatically
367 adjusting playback latency and buffer occupancy during normal playback by clients.
369 @item update_period @var{update_period}
370 Set the mpd update period ,for dynamic content.
378 Per-packet CRC (Cyclic Redundancy Check) testing format.
380 This muxer computes and prints the Adler-32 CRC for each audio
381 and video packet. By default audio frames are converted to signed
382 16-bit raw audio and video frames to raw video before computing the
385 The output of the muxer consists of a line for each audio and video
388 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, 0x@var{CRC}
391 @var{CRC} is a hexadecimal number 0-padded to 8 digits containing the
396 For example to compute the CRC of the audio and video frames in
397 @file{INPUT}, converted to raw audio and video packets, and store it
398 in the file @file{out.crc}:
400 ffmpeg -i INPUT -f framecrc out.crc
403 To print the information to stdout, use the command:
405 ffmpeg -i INPUT -f framecrc -
408 With @command{ffmpeg}, you can select the output format to which the
409 audio and video frames are encoded before computing the CRC for each
410 packet by specifying the audio and video codec. For example, to
411 compute the CRC of each decoded input audio frame converted to PCM
412 unsigned 8-bit and of each decoded input video frame converted to
413 MPEG-2 video, use the command:
415 ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -
418 See also the @ref{crc} muxer.
423 Per-packet hash testing format.
425 This muxer computes and prints a cryptographic hash for each audio
426 and video packet. This can be used for packet-by-packet equality
427 checks without having to individually do a binary comparison on each.
429 By default audio frames are converted to signed 16-bit raw audio and
430 video frames to raw video before computing the hash, but the output
431 of explicit conversions to other codecs can also be used. It uses the
432 SHA-256 cryptographic hash function by default, but supports several
435 The output of the muxer consists of a line for each audio and video
438 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, @var{hash}
441 @var{hash} is a hexadecimal number representing the computed hash
445 @item hash @var{algorithm}
446 Use the cryptographic hash function specified by the string @var{algorithm}.
447 Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
448 @code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
449 @code{SHA224}, @code{SHA256} (default), @code{SHA512/224}, @code{SHA512/256},
450 @code{SHA384}, @code{SHA512}, @code{CRC32} and @code{adler32}.
456 To compute the SHA-256 hash of the audio and video frames in @file{INPUT},
457 converted to raw audio and video packets, and store it in the file
460 ffmpeg -i INPUT -f framehash out.sha256
463 To print the information to stdout, using the MD5 hash function, use
466 ffmpeg -i INPUT -f framehash -hash md5 -
469 See also the @ref{hash} muxer.
474 Per-packet MD5 testing format.
476 This is a variant of the @ref{framehash} muxer. Unlike that muxer,
477 it defaults to using the MD5 hash function.
481 To compute the MD5 hash of the audio and video frames in @file{INPUT},
482 converted to raw audio and video packets, and store it in the file
485 ffmpeg -i INPUT -f framemd5 out.md5
488 To print the information to stdout, use the command:
490 ffmpeg -i INPUT -f framemd5 -
493 See also the @ref{framehash} and @ref{md5} muxers.
500 It accepts the following options:
504 Set the number of times to loop the output. Use @code{-1} for no loop, @code{0}
505 for looping indefinitely (default).
508 Force the delay (expressed in centiseconds) after the last frame. Each frame
509 ends with a delay until the next frame. The default is @code{-1}, which is a
510 special value to tell the muxer to re-use the previous delay. In case of a
511 loop, you might want to customize this value to mark a pause for instance.
514 For example, to encode a gif looping 10 times, with a 5 seconds delay between
517 ffmpeg -i INPUT -loop 10 -final_delay 500 out.gif
520 Note 1: if you wish to extract the frames into separate GIF files, you need to
521 force the @ref{image2} muxer:
523 ffmpeg -i INPUT -c:v gif -f image2 "out%d.gif"
526 Note 2: the GIF format has a very large time base: the delay between two frames
527 can therefore not be smaller than one centi second.
534 This muxer computes and prints a cryptographic hash of all the input
535 audio and video frames. This can be used for equality checks without
536 having to do a complete binary comparison.
538 By default audio frames are converted to signed 16-bit raw audio and
539 video frames to raw video before computing the hash, but the output
540 of explicit conversions to other codecs can also be used. Timestamps
541 are ignored. It uses the SHA-256 cryptographic hash function by default,
542 but supports several other algorithms.
544 The output of the muxer consists of a single line of the form:
545 @var{algo}=@var{hash}, where @var{algo} is a short string representing
546 the hash function used, and @var{hash} is a hexadecimal number
547 representing the computed hash.
550 @item hash @var{algorithm}
551 Use the cryptographic hash function specified by the string @var{algorithm}.
552 Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
553 @code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
554 @code{SHA224}, @code{SHA256} (default), @code{SHA512/224}, @code{SHA512/256},
555 @code{SHA384}, @code{SHA512}, @code{CRC32} and @code{adler32}.
561 To compute the SHA-256 hash of the input converted to raw audio and
562 video, and store it in the file @file{out.sha256}:
564 ffmpeg -i INPUT -f hash out.sha256
567 To print an MD5 hash to stdout use the command:
569 ffmpeg -i INPUT -f hash -hash md5 -
572 See also the @ref{framehash} muxer.
577 Apple HTTP Live Streaming muxer that segments MPEG-TS according to
578 the HTTP Live Streaming (HLS) specification.
580 It creates a playlist file, and one or more segment files. The output filename
581 specifies the playlist filename.
583 By default, the muxer creates a file for each segment produced. These files
584 have the same name as the playlist, followed by a sequential number and a
587 Make sure to require a closed GOP when encoding and to set the GOP
588 size to fit your segment time constraint.
590 For example, to convert an input file with @command{ffmpeg}:
592 ffmpeg -i in.mkv -c:v h264 -flags +cgop -g 30 -hls_time 1 out.m3u8
594 This example will produce the playlist, @file{out.m3u8}, and segment files:
595 @file{out0.ts}, @file{out1.ts}, @file{out2.ts}, etc.
597 See also the @ref{segment} muxer, which provides a more generic and
598 flexible implementation of a segmenter, and can be used to perform HLS
603 This muxer supports the following options:
606 @item hls_init_time @var{seconds}
607 Set the initial target segment length in seconds. Default value is @var{0}.
608 Segment will be cut on the next key frame after this time has passed on the first m3u8 list.
609 After the initial playlist is filled @command{ffmpeg} will cut segments
610 at duration equal to @code{hls_time}
612 @item hls_time @var{seconds}
613 Set the target segment length in seconds. Default value is 2.
614 Segment will be cut on the next key frame after this time has passed.
616 @item hls_list_size @var{size}
617 Set the maximum number of playlist entries. If set to 0 the list file
618 will contain all the segments. Default value is 5.
620 @item hls_delete_threshold @var{size}
621 Set the number of unreferenced segments to keep on disk before @code{hls_flags delete_segments}
622 deletes them. Increase this to allow continue clients to download segments which
623 were recently referenced in the playlist. Default value is 1, meaning segments older than
624 @code{hls_list_size+1} will be deleted.
626 @item hls_ts_options @var{options_list}
627 Set output format options using a :-separated list of key=value
628 parameters. Values containing @code{:} special characters must be
631 @item hls_wrap @var{wrap}
632 This is a deprecated option, you can use @code{hls_list_size}
633 and @code{hls_flags delete_segments} instead it
635 This option is useful to avoid to fill the disk with many segment
636 files, and limits the maximum number of segment files written to disk
640 @item hls_start_number_source
641 Start the playlist sequence number (@code{#EXT-X-MEDIA-SEQUENCE}) according to the specified source.
642 Unless @code{hls_flags single_file} is set, it also specifies source of starting sequence numbers of
643 segment and subtitle filenames. In any case, if @code{hls_flags append_list}
644 is set and read playlist sequence number is greater than the specified start sequence number,
645 then that value will be used as start value.
647 It accepts the following values:
651 @item generic (default)
652 Set the starting sequence numbers according to @var{start_number} option value.
655 The start number will be the seconds since epoch (1970-01-01 00:00:00)
658 The start number will be the microseconds since epoch (1970-01-01 00:00:00)
661 The start number will be based on the current date/time as YYYYmmddHHMMSS. e.g. 20161231235759.
665 @item start_number @var{number}
666 Start the playlist sequence number (@code{#EXT-X-MEDIA-SEQUENCE}) from the specified @var{number}
667 when @var{hls_start_number_source} value is @var{generic}. (This is the default case.)
668 Unless @code{hls_flags single_file} is set, it also specifies starting sequence numbers of segment and subtitle filenames.
671 @item hls_allow_cache @var{allowcache}
672 Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments.
674 @item hls_base_url @var{baseurl}
675 Append @var{baseurl} to every entry in the playlist.
676 Useful to generate playlists with absolute paths.
678 Note that the playlist sequence number must be unique for each segment
679 and it is not to be confused with the segment filename sequence number
680 which can be cyclic, for example if the @option{wrap} option is
683 @item hls_segment_filename @var{filename}
684 Set the segment filename. Unless @code{hls_flags single_file} is set,
685 @var{filename} is used as a string format with the segment number:
687 ffmpeg -i in.nut -hls_segment_filename 'file%03d.ts' out.m3u8
689 This example will produce the playlist, @file{out.m3u8}, and segment files:
690 @file{file000.ts}, @file{file001.ts}, @file{file002.ts}, etc.
692 @var{filename} may contain full path or relative path specification,
693 but only the file name part without any path info will be contained in the m3u8 segment list.
694 Should a relative path be specified, the path of the created segment
695 files will be relative to the current working directory.
696 When strftime_mkdir is set, the whole expanded value of @var{filename} will be written into the m3u8 segment list.
698 When @code{var_stream_map} is set with two or more variant streams, the
699 @var{filename} pattern must contain the string "%v", this string specifies
700 the position of variant stream index in the generated segment file names.
702 ffmpeg -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
703 -map 0:v -map 0:a -map 0:v -map 0:a -f hls -var_stream_map "v:0,a:0 v:1,a:1" \
704 -hls_segment_filename 'file_%v_%03d.ts' out_%v.m3u8
706 This example will produce the playlists segment file sets:
707 @file{file_0_000.ts}, @file{file_0_001.ts}, @file{file_0_002.ts}, etc. and
708 @file{file_1_000.ts}, @file{file_1_001.ts}, @file{file_1_002.ts}, etc.
710 The string "%v" may be present in the filename or in the last directory name
711 containing the file, but only in one of them. (Additionally, %v may appear multiple times in the last
712 sub-directory or filename.) If the string %v is present in the directory name, then
713 sub-directories are created after expanding the directory name pattern. This
714 enables creation of segments corresponding to different variant streams in
717 ffmpeg -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
718 -map 0:v -map 0:a -map 0:v -map 0:a -f hls -var_stream_map "v:0,a:0 v:1,a:1" \
719 -hls_segment_filename 'vs%v/file_%03d.ts' vs%v/out.m3u8
721 This example will produce the playlists segment file sets:
722 @file{vs0/file_000.ts}, @file{vs0/file_001.ts}, @file{vs0/file_002.ts}, etc. and
723 @file{vs1/file_000.ts}, @file{vs1/file_001.ts}, @file{vs1/file_002.ts}, etc.
726 Same as strftime option, will be deprecated.
729 Use strftime() on @var{filename} to expand the segment filename with localtime.
730 The segment number is also available in this mode, but to use it, you need to specify second_level_segment_index
731 hls_flag and %%d will be the specifier.
733 ffmpeg -i in.nut -strftime 1 -hls_segment_filename 'file-%Y%m%d-%s.ts' out.m3u8
735 This example will produce the playlist, @file{out.m3u8}, and segment files:
736 @file{file-20160215-1455569023.ts}, @file{file-20160215-1455569024.ts}, etc.
737 Note: On some systems/environments, the @code{%s} specifier is not available. See
738 @code{strftime()} documentation.
740 ffmpeg -i in.nut -strftime 1 -hls_flags second_level_segment_index -hls_segment_filename 'file-%Y%m%d-%%04d.ts' out.m3u8
742 This example will produce the playlist, @file{out.m3u8}, and segment files:
743 @file{file-20160215-0001.ts}, @file{file-20160215-0002.ts}, etc.
745 @item use_localtime_mkdir
746 Same as strftime_mkdir option, will be deprecated .
749 Used together with -strftime_mkdir, it will create all subdirectories which
750 is expanded in @var{filename}.
752 ffmpeg -i in.nut -strftime 1 -strftime_mkdir 1 -hls_segment_filename '%Y%m%d/file-%Y%m%d-%s.ts' out.m3u8
754 This example will create a directory 201560215 (if it does not exist), and then
755 produce the playlist, @file{out.m3u8}, and segment files:
756 @file{20160215/file-20160215-1455569023.ts}, @file{20160215/file-20160215-1455569024.ts}, etc.
759 ffmpeg -i in.nut -strftime 1 -strftime_mkdir 1 -hls_segment_filename '%Y/%m/%d/file-%Y%m%d-%s.ts' out.m3u8
761 This example will create a directory hierarchy 2016/02/15 (if any of them do not exist), and then
762 produce the playlist, @file{out.m3u8}, and segment files:
763 @file{2016/02/15/file-20160215-1455569023.ts}, @file{2016/02/15/file-20160215-1455569024.ts}, etc.
766 @item hls_key_info_file @var{key_info_file}
767 Use the information in @var{key_info_file} for segment encryption. The first
768 line of @var{key_info_file} specifies the key URI written to the playlist. The
769 key URL is used to access the encryption key during playback. The second line
770 specifies the path to the key file used to obtain the key during the encryption
771 process. The key file is read as a single packed array of 16 octets in binary
772 format. The optional third line specifies the initialization vector (IV) as a
773 hexadecimal string to be used instead of the segment sequence number (default)
774 for encryption. Changes to @var{key_info_file} will result in segment
775 encryption with the new key/IV and an entry in the playlist for the new key
776 URI/IV if @code{hls_flags periodic_rekey} is enabled.
778 Key info file format:
787 http://server/file.key
792 Example key file paths:
800 0123456789ABCDEF0123456789ABCDEF
803 Key info file example:
805 http://server/file.key
807 0123456789ABCDEF0123456789ABCDEF
810 Example shell script:
814 openssl rand 16 > file.key
815 echo $BASE_URL/file.key > file.keyinfo
816 echo file.key >> file.keyinfo
817 echo $(openssl rand -hex 16) >> file.keyinfo
818 ffmpeg -f lavfi -re -i testsrc -c:v h264 -hls_flags delete_segments \
819 -hls_key_info_file file.keyinfo out.m3u8
822 @item -hls_enc @var{enc}
823 Enable (1) or disable (0) the AES128 encryption.
824 When enabled every segment generated is encrypted and the encryption key
825 is saved as @var{playlist name}.key.
827 @item -hls_enc_key @var{key}
828 Hex-coded 16byte key to encrypt the segments, by default it
829 is randomly generated.
831 @item -hls_enc_key_url @var{keyurl}
832 If set, @var{keyurl} is prepended instead of @var{baseurl} to the key filename
835 @item -hls_enc_iv @var{iv}
836 Hex-coded 16byte initialization vector for every segment instead
837 of the autogenerated ones.
839 @item hls_segment_type @var{flags}
844 Output segment files in MPEG-2 Transport Stream format. This is
845 compatible with all HLS versions.
848 Output segment files in fragmented MP4 format, similar to MPEG-DASH.
849 fmp4 files may be used in HLS version 7 and above.
853 @item hls_fmp4_init_filename @var{filename}
854 Set filename to the fragment files header file, default filename is @file{init.mp4}.
856 @item hls_fmp4_init_resend
857 Resend init file after m3u8 file refresh every time, default is @var{0}.
859 When @code{var_stream_map} is set with two or more variant streams, the
860 @var{filename} pattern must contain the string "%v", this string specifies
861 the position of variant stream index in the generated init file names.
862 The string "%v" may be present in the filename or in the last directory name
863 containing the file. If the string is present in the directory name, then
864 sub-directories are created after expanding the directory name pattern. This
865 enables creation of init files corresponding to different variant streams in
868 @item hls_flags @var{flags}
873 If this flag is set, the muxer will store all segments in a single MPEG-TS
874 file, and will use byte ranges in the playlist. HLS playlists generated with
875 this way will have the version number 4.
878 ffmpeg -i in.nut -hls_flags single_file out.m3u8
880 Will produce the playlist, @file{out.m3u8}, and a single segment file,
883 @item delete_segments
884 Segment files removed from the playlist are deleted after a period of time
885 equal to the duration of the segment plus the duration of the playlist.
888 Append new segments into the end of old segment list,
889 and remove the @code{#EXT-X-ENDLIST} from the old segment list.
891 @item round_durations
892 Round the duration info in the playlist file segment info to integer
893 values, instead of using floating point.
896 Add the @code{#EXT-X-DISCONTINUITY} tag to the playlist, before the
897 first segment's information.
900 Do not append the @code{EXT-X-ENDLIST} tag at the end of the playlist.
903 The file specified by @code{hls_key_info_file} will be checked periodically and
904 detect updates to the encryption info. Be sure to replace this file atomically,
905 including the file containing the AES encryption key.
907 @item independent_segments
908 Add the @code{#EXT-X-INDEPENDENT-SEGMENTS} to playlists that has video segments
909 and when all the segments of that playlist are guaranteed to start with a Key frame.
912 Add the @code{#EXT-X-I-FRAMES-ONLY} to playlists that has video segments
913 and can play only I-frames in the @code{#EXT-X-BYTERANGE} mode.
916 Allow segments to start on frames other than keyframes. This improves
917 behavior on some players when the time between keyframes is inconsistent,
918 but may make things worse on others, and can cause some oddities during
919 seeking. This flag should be used with the @code{hls_time} option.
921 @item program_date_time
922 Generate @code{EXT-X-PROGRAM-DATE-TIME} tags.
924 @item second_level_segment_index
925 Makes it possible to use segment indexes as %%d in hls_segment_filename expression
926 besides date/time values when strftime is on.
927 To get fixed width numbers with trailing zeroes, %%0xd format is available where x is the required width.
929 @item second_level_segment_size
930 Makes it possible to use segment sizes (counted in bytes) as %%s in hls_segment_filename
931 expression besides date/time values when strftime is on.
932 To get fixed width numbers with trailing zeroes, %%0xs format is available where x is the required width.
934 @item second_level_segment_duration
935 Makes it possible to use segment duration (calculated in microseconds) as %%t in hls_segment_filename
936 expression besides date/time values when strftime is on.
937 To get fixed width numbers with trailing zeroes, %%0xt format is available where x is the required width.
940 ffmpeg -i sample.mpeg \
941 -f hls -hls_time 3 -hls_list_size 5 \
942 -hls_flags second_level_segment_index+second_level_segment_size+second_level_segment_duration \
943 -strftime 1 -strftime_mkdir 1 -hls_segment_filename "segment_%Y%m%d%H%M%S_%%04d_%%08s_%%013t.ts" stream.m3u8
945 This will produce segments like this:
946 @file{segment_20170102194334_0003_00122200_0000003000000.ts}, @file{segment_20170102194334_0004_00120072_0000003000000.ts} etc.
949 Write segment data to filename.tmp and rename to filename only once the segment is complete. A webserver
950 serving up segments can be configured to reject requests to *.tmp to prevent access to in-progress segments
951 before they have been added to the m3u8 playlist. This flag also affects how m3u8 playlist files are created.
952 If this flag is set, all playlist files will written into temporary file and renamed after they are complete, similarly as segments are handled.
953 But playlists with @code{file} protocol and with type (@code{hls_playlist_type}) other than @code{vod}
954 are always written into temporary file regardless of this flag. Master playlist files (@code{master_pl_name}), if any, with @code{file} protocol,
955 are always written into temporary file regardless of this flag if @code{master_pl_publish_rate} value is other than zero.
959 @item hls_playlist_type event
960 Emit @code{#EXT-X-PLAYLIST-TYPE:EVENT} in the m3u8 header. Forces
961 @option{hls_list_size} to 0; the playlist can only be appended to.
963 @item hls_playlist_type vod
964 Emit @code{#EXT-X-PLAYLIST-TYPE:VOD} in the m3u8 header. Forces
965 @option{hls_list_size} to 0; the playlist must not change.
968 Use the given HTTP method to create the hls files.
970 ffmpeg -re -i in.ts -f hls -method PUT http://example.com/live/out.m3u8
972 This example will upload all the mpegts segment files to the HTTP
973 server using the HTTP PUT method, and update the m3u8 files every
974 @code{refresh} times using the same method.
975 Note that the HTTP server must support the given method for uploading
978 @item http_user_agent
979 Override User-Agent field in HTTP header. Applicable only for HTTP output.
982 Map string which specifies how to group the audio, video and subtitle streams
983 into different variant streams. The variant stream groups are separated
985 Expected string format is like this "a:0,v:0 a:1,v:1 ....". Here a:, v:, s: are
986 the keys to specify audio, video and subtitle streams respectively.
987 Allowed values are 0 to 9 (limited just based on practical usage).
989 When there are two or more variant streams, the output filename pattern must
990 contain the string "%v", this string specifies the position of variant stream
991 index in the output media playlist filenames. The string "%v" may be present in
992 the filename or in the last directory name containing the file. If the string is
993 present in the directory name, then sub-directories are created after expanding
994 the directory name pattern. This enables creation of variant streams in
998 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
999 -map 0:v -map 0:a -map 0:v -map 0:a -f hls -var_stream_map "v:0,a:0 v:1,a:1" \
1000 http://example.com/live/out_%v.m3u8
1002 This example creates two hls variant streams. The first variant stream will
1003 contain video stream of bitrate 1000k and audio stream of bitrate 64k and the
1004 second variant stream will contain video stream of bitrate 256k and audio
1005 stream of bitrate 32k. Here, two media playlist with file names out_0.m3u8 and
1006 out_1.m3u8 will be created. If you want something meaningful text instead of indexes
1007 in result names, you may specify names for each or some of the variants
1008 as in the following example.
1012 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
1013 -map 0:v -map 0:a -map 0:v -map 0:a -f hls -var_stream_map "v:0,a:0,name:my_hd v:1,a:1,name:my_sd" \
1014 http://example.com/live/out_%v.m3u8
1017 This example creates two hls variant streams as in the previous one.
1018 But here, the two media playlist with file names out_my_hd.m3u8 and
1019 out_my_sd.m3u8 will be created.
1022 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k \
1023 -map 0:v -map 0:a -map 0:v -f hls -var_stream_map "v:0 a:0 v:1" \
1024 http://example.com/live/out_%v.m3u8
1026 This example creates three hls variant streams. The first variant stream will
1027 be a video only stream with video bitrate 1000k, the second variant stream will
1028 be an audio only stream with bitrate 64k and the third variant stream will be a
1029 video only stream with bitrate 256k. Here, three media playlist with file names
1030 out_0.m3u8, out_1.m3u8 and out_2.m3u8 will be created.
1032 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
1033 -map 0:v -map 0:a -map 0:v -map 0:a -f hls -var_stream_map "v:0,a:0 v:1,a:1" \
1034 http://example.com/live/vs_%v/out.m3u8
1036 This example creates the variant streams in subdirectories. Here, the first
1037 media playlist is created at @file{http://example.com/live/vs_0/out.m3u8} and
1038 the second one at @file{http://example.com/live/vs_1/out.m3u8}.
1040 ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k -b:v:1 3000k \
1041 -map 0:a -map 0:a -map 0:v -map 0:v -f hls \
1042 -var_stream_map "a:0,agroup:aud_low a:1,agroup:aud_high v:0,agroup:aud_low v:1,agroup:aud_high" \
1043 -master_pl_name master.m3u8 \
1044 http://example.com/live/out_%v.m3u8
1046 This example creates two audio only and two video only variant streams. In
1047 addition to the #EXT-X-STREAM-INF tag for each variant stream in the master
1048 playlist, #EXT-X-MEDIA tag is also added for the two audio only variant streams
1049 and they are mapped to the two video only variant streams with audio group names
1050 'aud_low' and 'aud_high'.
1052 By default, a single hls variant containing all the encoded streams is created.
1055 ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k \
1056 -map 0:a -map 0:a -map 0:v -f hls \
1057 -var_stream_map "a:0,agroup:aud_low,default:yes a:1,agroup:aud_low v:0,agroup:aud_low" \
1058 -master_pl_name master.m3u8 \
1059 http://example.com/live/out_%v.m3u8
1061 This example creates two audio only and one video only variant streams. In
1062 addition to the #EXT-X-STREAM-INF tag for each variant stream in the master
1063 playlist, #EXT-X-MEDIA tag is also added for the two audio only variant streams
1064 and they are mapped to the one video only variant streams with audio group name
1065 'aud_low', and the audio group have default stat is NO or YES.
1067 By default, a single hls variant containing all the encoded streams is created.
1070 ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k \
1071 -map 0:a -map 0:a -map 0:v -f hls \
1072 -var_stream_map "a:0,agroup:aud_low,default:yes,language:ENG a:1,agroup:aud_low,language:CHN v:0,agroup:aud_low" \
1073 -master_pl_name master.m3u8 \
1074 http://example.com/live/out_%v.m3u8
1076 This example creates two audio only and one video only variant streams. In
1077 addition to the #EXT-X-STREAM-INF tag for each variant stream in the master
1078 playlist, #EXT-X-MEDIA tag is also added for the two audio only variant streams
1079 and they are mapped to the one video only variant streams with audio group name
1080 'aud_low', and the audio group have default stat is NO or YES, and one audio
1081 have and language is named ENG, the other audio language is named CHN.
1083 By default, a single hls variant containing all the encoded streams is created.
1086 ffmpeg -y -i input_with_subtitle.mkv \
1087 -b:v:0 5250k -c:v h264 -pix_fmt yuv420p -profile:v main -level 4.1 \
1089 -c:s webvtt -c:a mp2 -ar 48000 -ac 2 -map 0:v -map 0:a:0 -map 0:s:0 \
1090 -f hls -var_stream_map "v:0,a:0,s:0,sgroup:subtitle" \
1091 -master_pl_name master.m3u8 -t 300 -hls_time 10 -hls_init_time 4 -hls_list_size \
1092 10 -master_pl_publish_rate 10 -hls_flags \
1093 delete_segments+discont_start+split_by_time ./tmp/video.m3u8
1096 This example adds @code{#EXT-X-MEDIA} tag with @code{TYPE=SUBTITLES} in
1097 the master playlist with webvtt subtitle group name 'subtitle'. Please make sure
1098 the input file has one text subtitle stream at least.
1101 Map string which specifies different closed captions groups and their
1102 attributes. The closed captions stream groups are separated by space.
1103 Expected string format is like this
1104 "ccgroup:<group name>,instreamid:<INSTREAM-ID>,language:<language code> ....".
1105 'ccgroup' and 'instreamid' are mandatory attributes. 'language' is an optional
1107 The closed captions groups configured using this option are mapped to different
1108 variant streams by providing the same 'ccgroup' name in the
1109 @code{var_stream_map} string. If @code{var_stream_map} is not set, then the
1110 first available ccgroup in @code{cc_stream_map} is mapped to the output variant
1111 stream. The examples for these two use cases are given below.
1114 ffmpeg -re -i in.ts -b:v 1000k -b:a 64k -a53cc 1 -f hls \
1115 -cc_stream_map "ccgroup:cc,instreamid:CC1,language:en" \
1116 -master_pl_name master.m3u8 \
1117 http://example.com/live/out.m3u8
1119 This example adds @code{#EXT-X-MEDIA} tag with @code{TYPE=CLOSED-CAPTIONS} in
1120 the master playlist with group name 'cc', language 'en' (english) and
1121 INSTREAM-ID 'CC1'. Also, it adds @code{CLOSED-CAPTIONS} attribute with group
1122 name 'cc' for the output variant stream.
1124 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
1125 -a53cc:0 1 -a53cc:1 1\
1126 -map 0:v -map 0:a -map 0:v -map 0:a -f hls \
1127 -cc_stream_map "ccgroup:cc,instreamid:CC1,language:en ccgroup:cc,instreamid:CC2,language:sp" \
1128 -var_stream_map "v:0,a:0,ccgroup:cc v:1,a:1,ccgroup:cc" \
1129 -master_pl_name master.m3u8 \
1130 http://example.com/live/out_%v.m3u8
1132 This example adds two @code{#EXT-X-MEDIA} tags with @code{TYPE=CLOSED-CAPTIONS} in
1133 the master playlist for the INSTREAM-IDs 'CC1' and 'CC2'. Also, it adds
1134 @code{CLOSED-CAPTIONS} attribute with group name 'cc' for the two output variant
1137 @item master_pl_name
1138 Create HLS master playlist with the given name.
1141 ffmpeg -re -i in.ts -f hls -master_pl_name master.m3u8 http://example.com/live/out.m3u8
1143 This example creates HLS master playlist with name master.m3u8 and it is
1144 published at http://example.com/live/
1146 @item master_pl_publish_rate
1147 Publish master play list repeatedly every after specified number of segment intervals.
1150 ffmpeg -re -i in.ts -f hls -master_pl_name master.m3u8 \
1151 -hls_time 2 -master_pl_publish_rate 30 http://example.com/live/out.m3u8
1154 This example creates HLS master playlist with name master.m3u8 and keep
1155 publishing it repeatedly every after 30 segments i.e. every after 60s.
1157 @item http_persistent
1158 Use persistent HTTP connections. Applicable only for HTTP output.
1161 Set timeout for socket I/O operations. Applicable only for HTTP output.
1163 @item -ignore_io_errors
1164 Ignore IO errors during open, write and delete. Useful for long-duration runs with network output.
1167 Set custom HTTP headers, can override built in default headers. Applicable only for HTTP output.
1176 Microsoft's icon file format (ICO) has some strict limitations that should be noted:
1180 Size cannot exceed 256 pixels in any dimension
1183 Only BMP and PNG images can be stored
1186 If a BMP image is used, it must be one of the following pixel formats:
1188 BMP Bit Depth FFmpeg Pixel Format
1198 If a BMP image is used, it must use the BITMAPINFOHEADER DIB header
1201 If a PNG image is used, it must use the rgba pixel format
1209 The image file muxer writes video frames to image files.
1211 The output filenames are specified by a pattern, which can be used to
1212 produce sequentially numbered series of files.
1213 The pattern may contain the string "%d" or "%0@var{N}d", this string
1214 specifies the position of the characters representing a numbering in
1215 the filenames. If the form "%0@var{N}d" is used, the string
1216 representing the number in each filename is 0-padded to @var{N}
1217 digits. The literal character '%' can be specified in the pattern with
1220 If the pattern contains "%d" or "%0@var{N}d", the first filename of
1221 the file list specified will contain the number 1, all the following
1222 numbers will be sequential.
1224 The pattern may contain a suffix which is used to automatically
1225 determine the format of the image files to write.
1227 For example the pattern "img-%03d.bmp" will specify a sequence of
1228 filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ...,
1229 @file{img-010.bmp}, etc.
1230 The pattern "img%%-%d.jpg" will specify a sequence of filenames of the
1231 form @file{img%-1.jpg}, @file{img%-2.jpg}, ..., @file{img%-10.jpg},
1234 The image muxer supports the .Y.U.V image file format. This format is
1235 special in that that each image frame consists of three files, for
1236 each of the YUV420P components. To read or write this image file format,
1237 specify the name of the '.Y' file. The muxer will automatically open the
1238 '.U' and '.V' files as required.
1244 If set to 1, expand the filename with pts from pkt->pts.
1248 Start the sequence from the specified number. Default value is 1.
1251 If set to 1, the filename will always be interpreted as just a
1252 filename, not a pattern, and the corresponding file will be continuously
1253 overwritten with new images. Default value is 0.
1256 If set to 1, expand the filename with date and time information from
1257 @code{strftime()}. Default value is 0.
1259 @item protocol_opts @var{options_list}
1260 Set protocol options as a :-separated list of key=value parameters. Values
1261 containing the @code{:} special character must be escaped.
1265 @subsection Examples
1267 The following example shows how to use @command{ffmpeg} for creating a
1268 sequence of files @file{img-001.jpeg}, @file{img-002.jpeg}, ...,
1269 taking one image every second from the input video:
1271 ffmpeg -i in.avi -vsync cfr -r 1 -f image2 'img-%03d.jpeg'
1274 Note that with @command{ffmpeg}, if the format is not specified with the
1275 @code{-f} option and the output filename specifies an image file
1276 format, the image2 muxer is automatically selected, so the previous
1277 command can be written as:
1279 ffmpeg -i in.avi -vsync cfr -r 1 'img-%03d.jpeg'
1282 Note also that the pattern must not necessarily contain "%d" or
1283 "%0@var{N}d", for example to create a single image file
1284 @file{img.jpeg} from the start of the input video you can employ the command:
1286 ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg
1289 The @option{strftime} option allows you to expand the filename with
1290 date and time information. Check the documentation of
1291 the @code{strftime()} function for the syntax.
1293 For example to generate image files from the @code{strftime()}
1294 "%Y-%m-%d_%H-%M-%S" pattern, the following @command{ffmpeg} command
1297 ffmpeg -f v4l2 -r 1 -i /dev/video0 -f image2 -strftime 1 "%Y-%m-%d_%H-%M-%S.jpg"
1300 You can set the file name with current frame's PTS:
1302 ffmpeg -f v4l2 -r 1 -i /dev/video0 -copyts -f image2 -frame_pts true %d.jpg"
1305 A more complex example is to publish contents of your desktop directly to a
1306 WebDAV server every second:
1308 ffmpeg -f x11grab -framerate 1 -i :0.0 -q:v 6 -update 1 -protocol_opts method=PUT http://example.com/desktop.jpg
1313 Matroska container muxer.
1315 This muxer implements the matroska and webm container specs.
1317 @subsection Metadata
1319 The recognized metadata settings in this muxer are:
1323 Set title name provided to a single track. This gets mapped to
1324 the FileDescription element for a stream written as attachment.
1327 Specify the language of the track in the Matroska languages form.
1329 The language can be either the 3 letters bibliographic ISO-639-2 (ISO
1330 639-2/B) form (like "fre" for French), or a language code mixed with a
1331 country code for specialities in languages (like "fre-ca" for Canadian
1335 Set stereo 3D video layout of two views in a single video track.
1337 The following values are recognized:
1342 Both views are arranged side by side, Left-eye view is on the left
1344 Both views are arranged in top-bottom orientation, Left-eye view is at bottom
1346 Both views are arranged in top-bottom orientation, Left-eye view is on top
1347 @item checkerboard_rl
1348 Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first
1349 @item checkerboard_lr
1350 Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first
1351 @item row_interleaved_rl
1352 Each view is constituted by a row based interleaving, Right-eye view is first row
1353 @item row_interleaved_lr
1354 Each view is constituted by a row based interleaving, Left-eye view is first row
1355 @item col_interleaved_rl
1356 Both views are arranged in a column based interleaving manner, Right-eye view is first column
1357 @item col_interleaved_lr
1358 Both views are arranged in a column based interleaving manner, Left-eye view is first column
1359 @item anaglyph_cyan_red
1360 All frames are in anaglyph format viewable through red-cyan filters
1362 Both views are arranged side by side, Right-eye view is on the left
1363 @item anaglyph_green_magenta
1364 All frames are in anaglyph format viewable through green-magenta filters
1366 Both eyes laced in one Block, Left-eye view is first
1368 Both eyes laced in one Block, Right-eye view is first
1372 For example a 3D WebM clip can be created using the following command line:
1374 ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm
1379 This muxer supports the following options:
1382 @item reserve_index_space
1383 By default, this muxer writes the index for seeking (called cues in Matroska
1384 terms) at the end of the file, because it cannot know in advance how much space
1385 to leave for the index at the beginning of the file. However for some use cases
1386 -- e.g. streaming where seeking is possible but slow -- it is useful to put the
1387 index at the beginning of the file.
1389 If this option is set to a non-zero value, the muxer will reserve a given amount
1390 of space in the file header and then try to write the cues there when the muxing
1391 finishes. If the reserved space does not suffice, no Cues will be written, the
1392 file will be finalized and writing the trailer will return an error.
1393 A safe size for most use cases should be about 50kB per hour of video.
1395 Note that cues are only written if the output is seekable and this option will
1396 have no effect if it is not.
1398 This option controls how the FlagDefault of the output tracks will be set.
1399 It influences which tracks players should play by default. The default mode
1403 In this mode, for each type of track (audio, video or subtitle), if there is
1404 a track with disposition default of this type, then the first such track
1405 (i.e. the one with the lowest index) will be marked as default; if no such
1406 track exists, the first track of this type will be marked as default instead
1407 (if existing). This ensures that the default flag is set in a sensible way even
1408 if the input originated from containers that lack the concept of default tracks.
1410 This mode is the same as infer except that if no subtitle track with
1411 disposition default exists, no subtitle track will be marked as default.
1413 In this mode the FlagDefault is set if and only if the AV_DISPOSITION_DEFAULT
1414 flag is set in the disposition of the corresponding stream.
1423 This is a variant of the @ref{hash} muxer. Unlike that muxer, it
1424 defaults to using the MD5 hash function.
1426 @subsection Examples
1428 To compute the MD5 hash of the input converted to raw
1429 audio and video, and store it in the file @file{out.md5}:
1431 ffmpeg -i INPUT -f md5 out.md5
1434 You can print the MD5 to stdout with the command:
1436 ffmpeg -i INPUT -f md5 -
1439 See also the @ref{hash} and @ref{framemd5} muxers.
1441 @section mov, mp4, ismv
1443 MOV/MP4/ISMV (Smooth Streaming) muxer.
1445 The mov/mp4/ismv muxer supports fragmentation. Normally, a MOV/MP4
1446 file has all the metadata about all packets stored in one location
1447 (written at the end of the file, it can be moved to the start for
1448 better playback by adding @var{faststart} to the @var{movflags}, or
1449 using the @command{qt-faststart} tool). A fragmented
1450 file consists of a number of fragments, where packets and metadata
1451 about these packets are stored together. Writing a fragmented
1452 file has the advantage that the file is decodable even if the
1453 writing is interrupted (while a normal MOV/MP4 is undecodable if
1454 it is not properly finished), and it requires less memory when writing
1455 very long files (since writing normal MOV/MP4 files stores info about
1456 every single packet in memory until the file is closed). The downside
1457 is that it is less compatible with other applications.
1461 Fragmentation is enabled by setting one of the AVOptions that define
1462 how to cut the file into fragments:
1465 @item -moov_size @var{bytes}
1466 Reserves space for the moov atom at the beginning of the file instead of placing the
1467 moov atom at the end. If the space reserved is insufficient, muxing will fail.
1468 @item -movflags frag_keyframe
1469 Start a new fragment at each video keyframe.
1470 @item -frag_duration @var{duration}
1471 Create fragments that are @var{duration} microseconds long.
1472 @item -frag_size @var{size}
1473 Create fragments that contain up to @var{size} bytes of payload data.
1474 @item -movflags frag_custom
1475 Allow the caller to manually choose when to cut fragments, by
1476 calling @code{av_write_frame(ctx, NULL)} to write a fragment with
1477 the packets written so far. (This is only useful with other
1478 applications integrating libavformat, not from @command{ffmpeg}.)
1479 @item -min_frag_duration @var{duration}
1480 Don't create fragments that are shorter than @var{duration} microseconds long.
1483 If more than one condition is specified, fragments are cut when
1484 one of the specified conditions is fulfilled. The exception to this is
1485 @code{-min_frag_duration}, which has to be fulfilled for any of the other
1486 conditions to apply.
1488 Additionally, the way the output file is written can be adjusted
1489 through a few other options:
1492 @item -movflags empty_moov
1493 Write an initial moov atom directly at the start of the file, without
1494 describing any samples in it. Generally, an mdat/moov pair is written
1495 at the start of the file, as a normal MOV/MP4 file, containing only
1496 a short portion of the file. With this option set, there is no initial
1497 mdat atom, and the moov atom only describes the tracks but has
1500 This option is implicitly set when writing ismv (Smooth Streaming) files.
1501 @item -movflags separate_moof
1502 Write a separate moof (movie fragment) atom for each track. Normally,
1503 packets for all tracks are written in a moof atom (which is slightly
1504 more efficient), but with this option set, the muxer writes one moof/mdat
1505 pair for each track, making it easier to separate tracks.
1507 This option is implicitly set when writing ismv (Smooth Streaming) files.
1508 @item -movflags skip_sidx
1509 Skip writing of sidx atom. When bitrate overhead due to sidx atom is high,
1510 this option could be used for cases where sidx atom is not mandatory.
1511 When global_sidx flag is enabled, this option will be ignored.
1512 @item -movflags faststart
1513 Run a second pass moving the index (moov atom) to the beginning of the file.
1514 This operation can take a while, and will not work in various situations such
1515 as fragmented output, thus it is not enabled by default.
1516 @item -movflags rtphint
1517 Add RTP hinting tracks to the output file.
1518 @item -movflags disable_chpl
1519 Disable Nero chapter markers (chpl atom). Normally, both Nero chapters
1520 and a QuickTime chapter track are written to the file. With this option
1521 set, only the QuickTime chapter track will be written. Nero chapters can
1522 cause failures when the file is reprocessed with certain tagging programs, like
1523 mp3Tag 2.61a and iTunes 11.3, most likely other versions are affected as well.
1524 @item -movflags omit_tfhd_offset
1525 Do not write any absolute base_data_offset in tfhd atoms. This avoids
1526 tying fragments to absolute byte positions in the file/streams.
1527 @item -movflags default_base_moof
1528 Similarly to the omit_tfhd_offset, this flag avoids writing the
1529 absolute base_data_offset field in tfhd atoms, but does so by using
1530 the new default-base-is-moof flag instead. This flag is new from
1531 14496-12:2012. This may make the fragments easier to parse in certain
1532 circumstances (avoiding basing track fragment location calculations
1533 on the implicit end of the previous track fragment).
1535 Specify @code{on} to force writing a timecode track, @code{off} to disable it
1536 and @code{auto} to write a timecode track only for mov and mp4 output (default).
1537 @item -movflags negative_cts_offsets
1538 Enables utilization of version 1 of the CTTS box, in which the CTS offsets can
1539 be negative. This enables the initial sample to have DTS/CTS of zero, and
1540 reduces the need for edit lists for some cases such as video tracks with
1541 B-frames. Additionally, eases conformance with the DASH-IF interoperability
1544 This option is implicitly set when writing ismv (Smooth Streaming) files.
1546 Write producer time reference box (PRFT) with a specified time source for the
1547 NTP field in the PRFT box. Set value as @samp{wallclock} to specify timesource
1548 as wallclock time and @samp{pts} to specify timesource as input packets' PTS
1551 Setting value to @samp{pts} is applicable only for a live encoding use case,
1552 where PTS values are set as as wallclock time at the source. For example, an
1553 encoding use case with decklink capture source where @option{video_pts} and
1554 @option{audio_pts} are set to @samp{abs_wallclock}.
1559 Smooth Streaming content can be pushed in real time to a publishing
1560 point on IIS with this muxer. Example:
1562 ffmpeg -re @var{<normal input/transcoding options>} -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1)
1567 The MP3 muxer writes a raw MP3 stream with the following optional features:
1570 An ID3v2 metadata header at the beginning (enabled by default). Versions 2.3 and
1571 2.4 are supported, the @code{id3v2_version} private option controls which one is
1572 used (3 or 4). Setting @code{id3v2_version} to 0 disables the ID3v2 header
1575 The muxer supports writing attached pictures (APIC frames) to the ID3v2 header.
1576 The pictures are supplied to the muxer in form of a video stream with a single
1577 packet. There can be any number of those streams, each will correspond to a
1578 single APIC frame. The stream metadata tags @var{title} and @var{comment} map
1579 to APIC @var{description} and @var{picture type} respectively. See
1580 @url{http://id3.org/id3v2.4.0-frames} for allowed picture types.
1582 Note that the APIC frames must be written at the beginning, so the muxer will
1583 buffer the audio frames until it gets all the pictures. It is therefore advised
1584 to provide the pictures as soon as possible to avoid excessive buffering.
1587 A Xing/LAME frame right after the ID3v2 header (if present). It is enabled by
1588 default, but will be written only if the output is seekable. The
1589 @code{write_xing} private option can be used to disable it. The frame contains
1590 various information that may be useful to the decoder, like the audio duration
1594 A legacy ID3v1 tag at the end of the file (disabled by default). It may be
1595 enabled with the @code{write_id3v1} private option, but as its capabilities are
1596 very limited, its usage is not recommended.
1601 Write an mp3 with an ID3v2.3 header and an ID3v1 footer:
1603 ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3
1606 To attach a picture to an mp3 file select both the audio and the picture stream
1609 ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1
1610 -metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3
1613 Write a "clean" MP3 without any extra features:
1615 ffmpeg -i input.wav -write_xing 0 -id3v2_version 0 out.mp3
1620 MPEG transport stream muxer.
1622 This muxer implements ISO 13818-1 and part of ETSI EN 300 468.
1624 The recognized metadata settings in mpegts muxer are @code{service_provider}
1625 and @code{service_name}. If they are not set the default for
1626 @code{service_provider} is @samp{FFmpeg} and the default for
1627 @code{service_name} is @samp{Service01}.
1631 The muxer options are:
1634 @item mpegts_transport_stream_id @var{integer}
1635 Set the @samp{transport_stream_id}. This identifies a transponder in DVB.
1636 Default is @code{0x0001}.
1638 @item mpegts_original_network_id @var{integer}
1639 Set the @samp{original_network_id}. This is unique identifier of a
1640 network in DVB. Its main use is in the unique identification of a service
1641 through the path @samp{Original_Network_ID, Transport_Stream_ID}. Default
1644 @item mpegts_service_id @var{integer}
1645 Set the @samp{service_id}, also known as program in DVB. Default is
1648 @item mpegts_service_type @var{integer}
1649 Set the program @samp{service_type}. Default is @code{digital_tv}.
1650 Accepts the following options:
1653 Any hexadecimal value between @code{0x01} and @code{0xff} as defined in
1658 Digital Radio service.
1661 @item advanced_codec_digital_radio
1662 Advanced Codec Digital Radio service.
1663 @item mpeg2_digital_hdtv
1664 MPEG2 Digital HDTV service.
1665 @item advanced_codec_digital_sdtv
1666 Advanced Codec Digital SDTV service.
1667 @item advanced_codec_digital_hdtv
1668 Advanced Codec Digital HDTV service.
1671 @item mpegts_pmt_start_pid @var{integer}
1672 Set the first PID for PMTs. Default is @code{0x1000}, minimum is @code{0x0020},
1673 maximum is @code{0x1ffa}. This option has no effect in m2ts mode where the PMT
1674 PID is fixed @code{0x0100}.
1676 @item mpegts_start_pid @var{integer}
1677 Set the first PID for elementary streams. Default is @code{0x0100}, minimum is
1678 @code{0x0020}, maximum is @code{0x1ffa}. This option has no effect in m2ts mode
1679 where the elementary stream PIDs are fixed.
1681 @item mpegts_m2ts_mode @var{boolean}
1682 Enable m2ts mode if set to @code{1}. Default value is @code{-1} which
1685 @item muxrate @var{integer}
1686 Set a constant muxrate. Default is VBR.
1688 @item pes_payload_size @var{integer}
1689 Set minimum PES packet payload in bytes. Default is @code{2930}.
1691 @item mpegts_flags @var{flags}
1692 Set mpegts flags. Accepts the following options:
1694 @item resend_headers
1695 Reemit PAT/PMT before writing the next packet.
1697 Use LATM packetization for AAC.
1698 @item pat_pmt_at_frames
1699 Reemit PAT and PMT at each video frame.
1701 Conform to System B (DVB) instead of System A (ATSC).
1702 @item initial_discontinuity
1703 Mark the initial packet of each stream as discontinuity.
1706 @item mpegts_copyts @var{boolean}
1707 Preserve original timestamps, if value is set to @code{1}. Default value
1708 is @code{-1}, which results in shifting timestamps so that they start from 0.
1710 @item omit_video_pes_length @var{boolean}
1711 Omit the PES packet length for video packets. Default is @code{1} (true).
1713 @item pcr_period @var{integer}
1714 Override the default PCR retransmission time in milliseconds. Default is
1715 @code{-1} which means that the PCR interval will be determined automatically:
1716 20 ms is used for CBR streams, the highest multiple of the frame duration which
1717 is less than 100 ms is used for VBR streams.
1719 @item pat_period @var{duration}
1720 Maximum time in seconds between PAT/PMT tables. Default is @code{0.1}.
1722 @item sdt_period @var{duration}
1723 Maximum time in seconds between SDT tables. Default is @code{0.5}.
1725 @item tables_version @var{integer}
1726 Set PAT, PMT and SDT version (default @code{0}, valid values are from 0 to 31, inclusively).
1727 This option allows updating stream structure so that standard consumer may
1728 detect the change. To do so, reopen output @code{AVFormatContext} (in case of API
1729 usage) or restart @command{ffmpeg} instance, cyclically changing
1730 @option{tables_version} value:
1733 ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
1734 ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
1736 ffmpeg -i source3.ts -codec copy -f mpegts -tables_version 31 udp://1.1.1.1:1111
1737 ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
1738 ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
1746 ffmpeg -i file.mpg -c copy \
1747 -mpegts_original_network_id 0x1122 \
1748 -mpegts_transport_stream_id 0x3344 \
1749 -mpegts_service_id 0x5566 \
1750 -mpegts_pmt_start_pid 0x1500 \
1751 -mpegts_start_pid 0x150 \
1752 -metadata service_provider="Some provider" \
1753 -metadata service_name="Some Channel" \
1757 @section mxf, mxf_d10, mxf_opatom
1763 The muxer options are:
1766 @item store_user_comments @var{bool}
1767 Set if user comments should be stored if available or never.
1768 IRT D-10 does not allow user comments. The default is thus to write them for
1769 mxf and mxf_opatom but not for mxf_d10
1776 This muxer does not generate any output file, it is mainly useful for
1777 testing or benchmarking purposes.
1779 For example to benchmark decoding with @command{ffmpeg} you can use the
1782 ffmpeg -benchmark -i INPUT -f null out.null
1785 Note that the above command does not read or write the @file{out.null}
1786 file, but specifying the output file is required by the @command{ffmpeg}
1789 Alternatively you can write the command as:
1791 ffmpeg -benchmark -i INPUT -f null -
1797 @item -syncpoints @var{flags}
1798 Change the syncpoint usage in nut:
1800 @item @var{default} use the normal low-overhead seeking aids.
1801 @item @var{none} do not use the syncpoints at all, reducing the overhead but making the stream non-seekable;
1802 Use of this option is not recommended, as the resulting files are very damage
1803 sensitive and seeking is not possible. Also in general the overhead from
1804 syncpoints is negligible. Note, -@code{write_index} 0 can be used to disable
1805 all growing data tables, allowing to mux endless streams with limited memory
1806 and without these disadvantages.
1807 @item @var{timestamped} extend the syncpoint with a wallclock field.
1809 The @var{none} and @var{timestamped} flags are experimental.
1810 @item -write_index @var{bool}
1811 Write index at the end, the default is to write an index.
1815 ffmpeg -i INPUT -f_strict experimental -syncpoints none - | processor
1820 Ogg container muxer.
1823 @item -page_duration @var{duration}
1824 Preferred page duration, in microseconds. The muxer will attempt to create
1825 pages that are approximately @var{duration} microseconds long. This allows the
1826 user to compromise between seek granularity and container overhead. The default
1827 is 1 second. A value of 0 will fill all segments, making pages as large as
1828 possible. A value of 1 will effectively use 1 packet-per-page in most
1829 situations, giving a small seek granularity at the cost of additional container
1831 @item -serial_offset @var{value}
1832 Serial value from which to set the streams serial number.
1833 Setting it to different and sufficiently large values ensures that the produced
1834 ogg files can be safely chained.
1839 @section segment, stream_segment, ssegment
1841 Basic stream segmenter.
1843 This muxer outputs streams to a number of separate files of nearly
1844 fixed duration. Output filename pattern can be set in a fashion
1845 similar to @ref{image2}, or by using a @code{strftime} template if
1846 the @option{strftime} option is enabled.
1848 @code{stream_segment} is a variant of the muxer used to write to
1849 streaming output formats, i.e. which do not require global headers,
1850 and is recommended for outputting e.g. to MPEG transport stream segments.
1851 @code{ssegment} is a shorter alias for @code{stream_segment}.
1853 Every segment starts with a keyframe of the selected reference stream,
1854 which is set through the @option{reference_stream} option.
1856 Note that if you want accurate splitting for a video file, you need to
1857 make the input key frames correspond to the exact splitting times
1858 expected by the segmenter, or the segment muxer will start the new
1859 segment with the key frame found next after the specified start
1862 The segment muxer works best with a single constant frame rate video.
1864 Optionally it can generate a list of the created segments, by setting
1865 the option @var{segment_list}. The list type is specified by the
1866 @var{segment_list_type} option. The entry filenames in the segment
1867 list are set by default to the basename of the corresponding segment
1870 See also the @ref{hls} muxer, which provides a more specific
1871 implementation for HLS segmentation.
1875 The segment muxer supports the following options:
1878 @item increment_tc @var{1|0}
1879 if set to @code{1}, increment timecode between each segment
1880 If this is selected, the input need to have
1881 a timecode in the first video stream. Default value is
1884 @item reference_stream @var{specifier}
1885 Set the reference stream, as specified by the string @var{specifier}.
1886 If @var{specifier} is set to @code{auto}, the reference is chosen
1887 automatically. Otherwise it must be a stream specifier (see the ``Stream
1888 specifiers'' chapter in the ffmpeg manual) which specifies the
1889 reference stream. The default value is @code{auto}.
1891 @item segment_format @var{format}
1892 Override the inner container format, by default it is guessed by the filename
1895 @item segment_format_options @var{options_list}
1896 Set output format options using a :-separated list of key=value
1897 parameters. Values containing the @code{:} special character must be
1900 @item segment_list @var{name}
1901 Generate also a listfile named @var{name}. If not specified no
1902 listfile is generated.
1904 @item segment_list_flags @var{flags}
1905 Set flags affecting the segment list generation.
1907 It currently supports the following flags:
1910 Allow caching (only affects M3U8 list files).
1913 Allow live-friendly file generation.
1916 @item segment_list_size @var{size}
1917 Update the list file so that it contains at most @var{size}
1918 segments. If 0 the list file will contain all the segments. Default
1921 @item segment_list_entry_prefix @var{prefix}
1922 Prepend @var{prefix} to each entry. Useful to generate absolute paths.
1923 By default no prefix is applied.
1925 @item segment_list_type @var{type}
1926 Select the listing format.
1928 The following values are recognized:
1931 Generate a flat list for the created segments, one segment per line.
1934 Generate a list for the created segments, one segment per line,
1935 each line matching the format (comma-separated values):
1937 @var{segment_filename},@var{segment_start_time},@var{segment_end_time}
1940 @var{segment_filename} is the name of the output file generated by the
1941 muxer according to the provided pattern. CSV escaping (according to
1942 RFC4180) is applied if required.
1944 @var{segment_start_time} and @var{segment_end_time} specify
1945 the segment start and end time expressed in seconds.
1947 A list file with the suffix @code{".csv"} or @code{".ext"} will
1948 auto-select this format.
1950 @samp{ext} is deprecated in favor or @samp{csv}.
1953 Generate an ffconcat file for the created segments. The resulting file
1954 can be read using the FFmpeg @ref{concat} demuxer.
1956 A list file with the suffix @code{".ffcat"} or @code{".ffconcat"} will
1957 auto-select this format.
1960 Generate an extended M3U8 file, version 3, compliant with
1961 @url{http://tools.ietf.org/id/draft-pantos-http-live-streaming}.
1963 A list file with the suffix @code{".m3u8"} will auto-select this format.
1966 If not specified the type is guessed from the list file name suffix.
1968 @item segment_time @var{time}
1969 Set segment duration to @var{time}, the value must be a duration
1970 specification. Default value is "2". See also the
1971 @option{segment_times} option.
1973 Note that splitting may not be accurate, unless you force the
1974 reference stream key-frames at the given time. See the introductory
1975 notice and the examples below.
1977 @item segment_atclocktime @var{1|0}
1978 If set to "1" split at regular clock time intervals starting from 00:00
1979 o'clock. The @var{time} value specified in @option{segment_time} is
1980 used for setting the length of the splitting interval.
1982 For example with @option{segment_time} set to "900" this makes it possible
1983 to create files at 12:00 o'clock, 12:15, 12:30, etc.
1985 Default value is "0".
1987 @item segment_clocktime_offset @var{duration}
1988 Delay the segment splitting times with the specified duration when using
1989 @option{segment_atclocktime}.
1991 For example with @option{segment_time} set to "900" and
1992 @option{segment_clocktime_offset} set to "300" this makes it possible to
1993 create files at 12:05, 12:20, 12:35, etc.
1995 Default value is "0".
1997 @item segment_clocktime_wrap_duration @var{duration}
1998 Force the segmenter to only start a new segment if a packet reaches the muxer
1999 within the specified duration after the segmenting clock time. This way you
2000 can make the segmenter more resilient to backward local time jumps, such as
2001 leap seconds or transition to standard time from daylight savings time.
2003 Default is the maximum possible duration which means starting a new segment
2004 regardless of the elapsed time since the last clock time.
2006 @item segment_time_delta @var{delta}
2007 Specify the accuracy time when selecting the start time for a
2008 segment, expressed as a duration specification. Default value is "0".
2010 When delta is specified a key-frame will start a new segment if its
2011 PTS satisfies the relation:
2013 PTS >= start_time - time_delta
2016 This option is useful when splitting video content, which is always
2017 split at GOP boundaries, in case a key frame is found just before the
2018 specified split time.
2020 In particular may be used in combination with the @file{ffmpeg} option
2021 @var{force_key_frames}. The key frame times specified by
2022 @var{force_key_frames} may not be set accurately because of rounding
2023 issues, with the consequence that a key frame time may result set just
2024 before the specified time. For constant frame rate videos a value of
2025 1/(2*@var{frame_rate}) should address the worst case mismatch between
2026 the specified time and the time set by @var{force_key_frames}.
2028 @item segment_times @var{times}
2029 Specify a list of split points. @var{times} contains a list of comma
2030 separated duration specifications, in increasing order. See also
2031 the @option{segment_time} option.
2033 @item segment_frames @var{frames}
2034 Specify a list of split video frame numbers. @var{frames} contains a
2035 list of comma separated integer numbers, in increasing order.
2037 This option specifies to start a new segment whenever a reference
2038 stream key frame is found and the sequential number (starting from 0)
2039 of the frame is greater or equal to the next value in the list.
2041 @item segment_wrap @var{limit}
2042 Wrap around segment index once it reaches @var{limit}.
2044 @item segment_start_number @var{number}
2045 Set the sequence number of the first segment. Defaults to @code{0}.
2047 @item strftime @var{1|0}
2048 Use the @code{strftime} function to define the name of the new
2049 segments to write. If this is selected, the output segment name must
2050 contain a @code{strftime} function template. Default value is
2053 @item break_non_keyframes @var{1|0}
2054 If enabled, allow segments to start on frames other than keyframes. This
2055 improves behavior on some players when the time between keyframes is
2056 inconsistent, but may make things worse on others, and can cause some oddities
2057 during seeking. Defaults to @code{0}.
2059 @item reset_timestamps @var{1|0}
2060 Reset timestamps at the beginning of each segment, so that each segment
2061 will start with near-zero timestamps. It is meant to ease the playback
2062 of the generated segments. May not work with some combinations of
2063 muxers/codecs. It is set to @code{0} by default.
2065 @item initial_offset @var{offset}
2066 Specify timestamp offset to apply to the output packet timestamps. The
2067 argument must be a time duration specification, and defaults to 0.
2069 @item write_empty_segments @var{1|0}
2070 If enabled, write an empty segment if there are no packets during the period a
2071 segment would usually span. Otherwise, the segment will be filled with the next
2072 packet written. Defaults to @code{0}.
2075 Make sure to require a closed GOP when encoding and to set the GOP
2076 size to fit your segment time constraint.
2078 @subsection Examples
2082 Remux the content of file @file{in.mkv} to a list of segments
2083 @file{out-000.nut}, @file{out-001.nut}, etc., and write the list of
2084 generated segments to @file{out.list}:
2086 ffmpeg -i in.mkv -codec hevc -flags +cgop -g 60 -map 0 -f segment -segment_list out.list out%03d.nut
2090 Segment input and set output format options for the output segments:
2092 ffmpeg -i in.mkv -f segment -segment_time 10 -segment_format_options movflags=+faststart out%03d.mp4
2096 Segment the input file according to the split points specified by the
2097 @var{segment_times} option:
2099 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
2103 Use the @command{ffmpeg} @option{force_key_frames}
2104 option to force key frames in the input at the specified location, together
2105 with the segment option @option{segment_time_delta} to account for
2106 possible roundings operated when setting key frame times.
2108 ffmpeg -i in.mkv -force_key_frames 1,2,3,5,8,13,21 -codec:v mpeg4 -codec:a pcm_s16le -map 0 \
2109 -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 -segment_time_delta 0.05 out%03d.nut
2111 In order to force key frames on the input file, transcoding is
2115 Segment the input file by splitting the input file according to the
2116 frame numbers sequence specified with the @option{segment_frames} option:
2118 ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_frames 100,200,300,500,800 out%03d.nut
2122 Convert the @file{in.mkv} to TS segments using the @code{libx264}
2123 and @code{aac} encoders:
2125 ffmpeg -i in.mkv -map 0 -codec:v libx264 -codec:a aac -f ssegment -segment_list out.list out%03d.ts
2129 Segment the input file, and create an M3U8 live playlist (can be used
2130 as live HLS source):
2132 ffmpeg -re -i in.mkv -codec copy -map 0 -f segment -segment_list playlist.m3u8 \
2133 -segment_list_flags +live -segment_time 10 out%03d.mkv
2137 @section smoothstreaming
2139 Smooth Streaming muxer generates a set of files (Manifest, chunks) suitable for serving with conventional web server.
2143 Specify the number of fragments kept in the manifest. Default 0 (keep all).
2145 @item extra_window_size
2146 Specify the number of fragments kept outside of the manifest before removing from disk. Default 5.
2148 @item lookahead_count
2149 Specify the number of lookahead fragments. Default 2.
2151 @item min_frag_duration
2152 Specify the minimum fragment duration (in microseconds). Default 5000000.
2154 @item remove_at_exit
2155 Specify whether to remove all fragments when finished. Default 0 (do not remove).
2162 Per stream hash testing format.
2164 This muxer computes and prints a cryptographic hash of all the input frames,
2165 on a per-stream basis. This can be used for equality checks without having
2166 to do a complete binary comparison.
2168 By default audio frames are converted to signed 16-bit raw audio and
2169 video frames to raw video before computing the hash, but the output
2170 of explicit conversions to other codecs can also be used. Timestamps
2171 are ignored. It uses the SHA-256 cryptographic hash function by default,
2172 but supports several other algorithms.
2174 The output of the muxer consists of one line per stream of the form:
2175 @var{streamindex},@var{streamtype},@var{algo}=@var{hash}, where
2176 @var{streamindex} is the index of the mapped stream, @var{streamtype} is a
2177 single character indicating the type of stream, @var{algo} is a short string
2178 representing the hash function used, and @var{hash} is a hexadecimal number
2179 representing the computed hash.
2182 @item hash @var{algorithm}
2183 Use the cryptographic hash function specified by the string @var{algorithm}.
2184 Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
2185 @code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
2186 @code{SHA224}, @code{SHA256} (default), @code{SHA512/224}, @code{SHA512/256},
2187 @code{SHA384}, @code{SHA512}, @code{CRC32} and @code{adler32}.
2191 @subsection Examples
2193 To compute the SHA-256 hash of the input converted to raw audio and
2194 video, and store it in the file @file{out.sha256}:
2196 ffmpeg -i INPUT -f streamhash out.sha256
2199 To print an MD5 hash to stdout use the command:
2201 ffmpeg -i INPUT -f streamhash -hash md5 -
2204 See also the @ref{hash} and @ref{framehash} muxers.
2209 The fifo pseudo-muxer allows the separation of encoding and muxing by using
2210 first-in-first-out queue and running the actual muxer in a separate thread. This
2211 is especially useful in combination with the @ref{tee} muxer and can be used to
2212 send data to several destinations with different reliability/writing speed/latency.
2214 API users should be aware that callback functions (interrupt_callback,
2215 io_open and io_close) used within its AVFormatContext must be thread-safe.
2217 The behavior of the fifo muxer if the queue fills up or if the output fails is
2223 output can be transparently restarted with configurable delay between retries
2224 based on real time or time of the processed stream.
2227 encoding can be blocked during temporary failure, or continue transparently
2228 dropping packets in case fifo queue fills up.
2235 Specify the format name. Useful if it cannot be guessed from the
2239 Specify size of the queue (number of packets). Default value is 60.
2242 Specify format options for the underlying muxer. Muxer options can be specified
2243 as a list of @var{key}=@var{value} pairs separated by ':'.
2245 @item drop_pkts_on_overflow @var{bool}
2246 If set to 1 (true), in case the fifo queue fills up, packets will be dropped
2247 rather than blocking the encoder. This makes it possible to continue streaming without
2248 delaying the input, at the cost of omitting part of the stream. By default
2249 this option is set to 0 (false), so in such cases the encoder will be blocked
2250 until the muxer processes some of the packets and none of them is lost.
2252 @item attempt_recovery @var{bool}
2253 If failure occurs, attempt to recover the output. This is especially useful
2254 when used with network output, since it makes it possible to restart streaming transparently.
2255 By default this option is set to 0 (false).
2257 @item max_recovery_attempts
2258 Sets maximum number of successive unsuccessful recovery attempts after which
2259 the output fails permanently. By default this option is set to 0 (unlimited).
2261 @item recovery_wait_time @var{duration}
2262 Waiting time before the next recovery attempt after previous unsuccessful
2263 recovery attempt. Default value is 5 seconds.
2265 @item recovery_wait_streamtime @var{bool}
2266 If set to 0 (false), the real time is used when waiting for the recovery
2267 attempt (i.e. the recovery will be attempted after at least
2268 recovery_wait_time seconds).
2269 If set to 1 (true), the time of the processed stream is taken into account
2270 instead (i.e. the recovery will be attempted after at least @var{recovery_wait_time}
2271 seconds of the stream is omitted).
2272 By default, this option is set to 0 (false).
2274 @item recover_any_error @var{bool}
2275 If set to 1 (true), recovery will be attempted regardless of type of the error
2276 causing the failure. By default this option is set to 0 (false) and in case of
2277 certain (usually permanent) errors the recovery is not attempted even when
2278 @var{attempt_recovery} is set to 1.
2280 @item restart_with_keyframe @var{bool}
2281 Specify whether to wait for the keyframe after recovering from
2282 queue overflow or failure. This option is set to 0 (false) by default.
2284 @item timeshift @var{duration}
2285 Buffer the specified amount of packets and delay writing the output. Note that
2286 @var{queue_size} must be big enough to store the packets for timeshift. At the
2287 end of the input the fifo buffer is flushed at realtime speed.
2291 @subsection Examples
2296 Stream something to rtmp server, continue processing the stream at real-time
2297 rate even in case of temporary failure (network outage) and attempt to recover
2298 streaming every second indefinitely.
2300 ffmpeg -re -i ... -c:v libx264 -c:a aac -f fifo -fifo_format flv -map 0:v -map 0:a
2301 -drop_pkts_on_overflow 1 -attempt_recovery 1 -recovery_wait_time 1 rtmp://example.com/live/stream_name
2309 The tee muxer can be used to write the same data to several outputs, such as files or streams.
2310 It can be used, for example, to stream a video over a network and save it to disk at the same time.
2312 It is different from specifying several outputs to the @command{ffmpeg}
2313 command-line tool. With the tee muxer, the audio and video data will be encoded only once.
2314 With conventional multiple outputs, multiple encoding operations in parallel are initiated,
2315 which can be a very expensive process. The tee muxer is not useful when using the libavformat API
2316 directly because it is then possible to feed the same packets to several muxers directly.
2318 Since the tee muxer does not represent any particular output format, ffmpeg cannot auto-select
2319 output streams. So all streams intended for output must be specified using @code{-map}. See
2322 Some encoders may need different options depending on the output format;
2323 the auto-detection of this can not work with the tee muxer, so they need to be explicitly specified.
2324 The main example is the @option{global_header} flag.
2326 The slave outputs are specified in the file name given to the muxer,
2327 separated by '|'. If any of the slave name contains the '|' separator,
2328 leading or trailing spaces or any special character, those must be
2329 escaped (see @ref{quoting_and_escaping,,the "Quoting and escaping"
2330 section in the ffmpeg-utils(1) manual,ffmpeg-utils}).
2336 @item use_fifo @var{bool}
2337 If set to 1, slave outputs will be processed in separate threads using the @ref{fifo}
2338 muxer. This allows to compensate for different speed/latency/reliability of
2339 outputs and setup transparent recovery. By default this feature is turned off.
2342 Options to pass to fifo pseudo-muxer instances. See @ref{fifo}.
2346 Muxer options can be specified for each slave by prepending them as a list of
2347 @var{key}=@var{value} pairs separated by ':', between square brackets. If
2348 the options values contain a special character or the ':' separator, they
2349 must be escaped; note that this is a second level escaping.
2351 The following special options are also recognized:
2354 Specify the format name. Required if it cannot be guessed from the
2357 @item bsfs[/@var{spec}]
2358 Specify a list of bitstream filters to apply to the specified
2361 It is possible to specify to which streams a given bitstream filter
2362 applies, by appending a stream specifier to the option separated by
2363 @code{/}. @var{spec} must be a stream specifier (see @ref{Format
2364 stream specifiers}).
2366 If the stream specifier is not specified, the bitstream filters will be
2367 applied to all streams in the output. This will cause that output operation
2368 to fail if the output contains streams to which the bitstream filter cannot
2369 be applied e.g. @code{h264_mp4toannexb} being applied to an output containing an audio stream.
2371 Options for a bitstream filter must be specified in the form of @code{opt=value}.
2373 Several bitstream filters can be specified, separated by ",".
2375 @item use_fifo @var{bool}
2376 This allows to override tee muxer use_fifo option for individual slave muxer.
2379 This allows to override tee muxer fifo_options for individual slave muxer.
2383 Select the streams that should be mapped to the slave output,
2384 specified by a stream specifier. If not specified, this defaults to
2385 all the mapped streams. This will cause that output operation to fail
2386 if the output format does not accept all mapped streams.
2388 You may use multiple stream specifiers separated by commas (@code{,}) e.g.: @code{a:0,v}
2391 Specify behaviour on output failure. This can be set to either @code{abort} (which is
2392 default) or @code{ignore}. @code{abort} will cause whole process to fail in case of failure
2393 on this slave output. @code{ignore} will ignore failure on this output, so other outputs
2394 will continue without being affected.
2397 @subsection Examples
2401 Encode something and both archive it in a WebM file and stream it
2402 as MPEG-TS over UDP:
2404 ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
2405 "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
2409 As above, but continue streaming even if output to local file fails
2410 (for example local drive fills up):
2412 ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
2413 "[onfail=ignore]archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
2417 Use @command{ffmpeg} to encode the input, and send the output
2418 to three different destinations. The @code{dump_extra} bitstream
2419 filter is used to add extradata information to all the output video
2420 keyframes packets, as requested by the MPEG-TS format. The select
2421 option is applied to @file{out.aac} in order to make it contain only
2424 ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
2425 -f tee "[bsfs/v=dump_extra=freq=keyframe]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac"
2429 As above, but select only stream @code{a:1} for the audio output. Note
2430 that a second level escaping must be performed, as ":" is a special
2431 character used to separate options.
2433 ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
2434 -f tee "[bsfs/v=dump_extra=freq=keyframe]out.ts|[movflags=+faststart]out.mp4|[select=\'a:1\']out.aac"
2438 @section webm_dash_manifest
2440 WebM DASH Manifest muxer.
2442 This muxer implements the WebM DASH Manifest specification to generate the DASH
2443 manifest XML. It also supports manifest generation for DASH live streams.
2445 For more information see:
2449 WebM DASH Specification: @url{https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification}
2451 ISO DASH Specification: @url{http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip}
2456 This muxer supports the following options:
2459 @item adaptation_sets
2460 This option has the following syntax: "id=x,streams=a,b,c id=y,streams=d,e" where x and y are the
2461 unique identifiers of the adaptation sets and a,b,c,d and e are the indices of the corresponding
2462 audio and video streams. Any number of adaptation sets can be added using this option.
2465 Set this to 1 to create a live stream DASH Manifest. Default: 0.
2467 @item chunk_start_index
2468 Start index of the first chunk. This will go in the @samp{startNumber} attribute
2469 of the @samp{SegmentTemplate} element in the manifest. Default: 0.
2471 @item chunk_duration_ms
2472 Duration of each chunk in milliseconds. This will go in the @samp{duration}
2473 attribute of the @samp{SegmentTemplate} element in the manifest. Default: 1000.
2475 @item utc_timing_url
2476 URL of the page that will return the UTC timestamp in ISO format. This will go
2477 in the @samp{value} attribute of the @samp{UTCTiming} element in the manifest.
2480 @item time_shift_buffer_depth
2481 Smallest time (in seconds) shifting buffer for which any Representation is
2482 guaranteed to be available. This will go in the @samp{timeShiftBufferDepth}
2483 attribute of the @samp{MPD} element. Default: 60.
2485 @item minimum_update_period
2486 Minimum update period (in seconds) of the manifest. This will go in the
2487 @samp{minimumUpdatePeriod} attribute of the @samp{MPD} element. Default: 0.
2493 ffmpeg -f webm_dash_manifest -i video1.webm \
2494 -f webm_dash_manifest -i video2.webm \
2495 -f webm_dash_manifest -i audio1.webm \
2496 -f webm_dash_manifest -i audio2.webm \
2497 -map 0 -map 1 -map 2 -map 3 \
2499 -f webm_dash_manifest \
2500 -adaptation_sets "id=0,streams=0,1 id=1,streams=2,3" \
2506 WebM Live Chunk Muxer.
2508 This muxer writes out WebM headers and chunks as separate files which can be
2509 consumed by clients that support WebM Live streams via DASH.
2513 This muxer supports the following options:
2516 @item chunk_start_index
2517 Index of the first chunk (defaults to 0).
2520 Filename of the header where the initialization data will be written.
2522 @item audio_chunk_duration
2523 Duration of each audio chunk in milliseconds (defaults to 5000).
2528 ffmpeg -f v4l2 -i /dev/video0 \
2532 -s 640x360 -keyint_min 30 -g 30 \
2534 -header webm_live_video_360.hdr \
2535 -chunk_start_index 1 \
2536 webm_live_video_360_%d.chk \
2541 -header webm_live_audio_128.hdr \
2542 -chunk_start_index 1 \
2543 -audio_chunk_duration 1000 \
2544 webm_live_audio_128_%d.chk