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.
374 Per-packet CRC (Cyclic Redundancy Check) testing format.
376 This muxer computes and prints the Adler-32 CRC for each audio
377 and video packet. By default audio frames are converted to signed
378 16-bit raw audio and video frames to raw video before computing the
381 The output of the muxer consists of a line for each audio and video
384 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, 0x@var{CRC}
387 @var{CRC} is a hexadecimal number 0-padded to 8 digits containing the
392 For example to compute the CRC of the audio and video frames in
393 @file{INPUT}, converted to raw audio and video packets, and store it
394 in the file @file{out.crc}:
396 ffmpeg -i INPUT -f framecrc out.crc
399 To print the information to stdout, use the command:
401 ffmpeg -i INPUT -f framecrc -
404 With @command{ffmpeg}, you can select the output format to which the
405 audio and video frames are encoded before computing the CRC for each
406 packet by specifying the audio and video codec. For example, to
407 compute the CRC of each decoded input audio frame converted to PCM
408 unsigned 8-bit and of each decoded input video frame converted to
409 MPEG-2 video, use the command:
411 ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -
414 See also the @ref{crc} muxer.
419 Per-packet hash testing format.
421 This muxer computes and prints a cryptographic hash for each audio
422 and video packet. This can be used for packet-by-packet equality
423 checks without having to individually do a binary comparison on each.
425 By default audio frames are converted to signed 16-bit raw audio and
426 video frames to raw video before computing the hash, but the output
427 of explicit conversions to other codecs can also be used. It uses the
428 SHA-256 cryptographic hash function by default, but supports several
431 The output of the muxer consists of a line for each audio and video
434 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, @var{hash}
437 @var{hash} is a hexadecimal number representing the computed hash
441 @item hash @var{algorithm}
442 Use the cryptographic hash function specified by the string @var{algorithm}.
443 Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
444 @code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
445 @code{SHA224}, @code{SHA256} (default), @code{SHA512/224}, @code{SHA512/256},
446 @code{SHA384}, @code{SHA512}, @code{CRC32} and @code{adler32}.
452 To compute the SHA-256 hash of the audio and video frames in @file{INPUT},
453 converted to raw audio and video packets, and store it in the file
456 ffmpeg -i INPUT -f framehash out.sha256
459 To print the information to stdout, using the MD5 hash function, use
462 ffmpeg -i INPUT -f framehash -hash md5 -
465 See also the @ref{hash} muxer.
470 Per-packet MD5 testing format.
472 This is a variant of the @ref{framehash} muxer. Unlike that muxer,
473 it defaults to using the MD5 hash function.
477 To compute the MD5 hash of the audio and video frames in @file{INPUT},
478 converted to raw audio and video packets, and store it in the file
481 ffmpeg -i INPUT -f framemd5 out.md5
484 To print the information to stdout, use the command:
486 ffmpeg -i INPUT -f framemd5 -
489 See also the @ref{framehash} and @ref{md5} muxers.
496 It accepts the following options:
500 Set the number of times to loop the output. Use @code{-1} for no loop, @code{0}
501 for looping indefinitely (default).
504 Force the delay (expressed in centiseconds) after the last frame. Each frame
505 ends with a delay until the next frame. The default is @code{-1}, which is a
506 special value to tell the muxer to re-use the previous delay. In case of a
507 loop, you might want to customize this value to mark a pause for instance.
510 For example, to encode a gif looping 10 times, with a 5 seconds delay between
513 ffmpeg -i INPUT -loop 10 -final_delay 500 out.gif
516 Note 1: if you wish to extract the frames into separate GIF files, you need to
517 force the @ref{image2} muxer:
519 ffmpeg -i INPUT -c:v gif -f image2 "out%d.gif"
522 Note 2: the GIF format has a very large time base: the delay between two frames
523 can therefore not be smaller than one centi second.
530 This muxer computes and prints a cryptographic hash of all the input
531 audio and video frames. This can be used for equality checks without
532 having to do a complete binary comparison.
534 By default audio frames are converted to signed 16-bit raw audio and
535 video frames to raw video before computing the hash, but the output
536 of explicit conversions to other codecs can also be used. Timestamps
537 are ignored. It uses the SHA-256 cryptographic hash function by default,
538 but supports several other algorithms.
540 The output of the muxer consists of a single line of the form:
541 @var{algo}=@var{hash}, where @var{algo} is a short string representing
542 the hash function used, and @var{hash} is a hexadecimal number
543 representing the computed hash.
546 @item hash @var{algorithm}
547 Use the cryptographic hash function specified by the string @var{algorithm}.
548 Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
549 @code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
550 @code{SHA224}, @code{SHA256} (default), @code{SHA512/224}, @code{SHA512/256},
551 @code{SHA384}, @code{SHA512}, @code{CRC32} and @code{adler32}.
557 To compute the SHA-256 hash of the input converted to raw audio and
558 video, and store it in the file @file{out.sha256}:
560 ffmpeg -i INPUT -f hash out.sha256
563 To print an MD5 hash to stdout use the command:
565 ffmpeg -i INPUT -f hash -hash md5 -
568 See also the @ref{framehash} muxer.
573 Apple HTTP Live Streaming muxer that segments MPEG-TS according to
574 the HTTP Live Streaming (HLS) specification.
576 It creates a playlist file, and one or more segment files. The output filename
577 specifies the playlist filename.
579 By default, the muxer creates a file for each segment produced. These files
580 have the same name as the playlist, followed by a sequential number and a
583 Make sure to require a closed GOP when encoding and to set the GOP
584 size to fit your segment time constraint.
586 For example, to convert an input file with @command{ffmpeg}:
588 ffmpeg -i in.mkv -c:v h264 -flags +cgop -g 30 -hls_time 1 out.m3u8
590 This example will produce the playlist, @file{out.m3u8}, and segment files:
591 @file{out0.ts}, @file{out1.ts}, @file{out2.ts}, etc.
593 See also the @ref{segment} muxer, which provides a more generic and
594 flexible implementation of a segmenter, and can be used to perform HLS
599 This muxer supports the following options:
602 @item hls_init_time @var{seconds}
603 Set the initial target segment length in seconds. Default value is @var{0}.
604 Segment will be cut on the next key frame after this time has passed on the first m3u8 list.
605 After the initial playlist is filled @command{ffmpeg} will cut segments
606 at duration equal to @code{hls_time}
608 @item hls_time @var{seconds}
609 Set the target segment length in seconds. Default value is 2.
610 Segment will be cut on the next key frame after this time has passed.
612 @item hls_list_size @var{size}
613 Set the maximum number of playlist entries. If set to 0 the list file
614 will contain all the segments. Default value is 5.
616 @item hls_delete_threshold @var{size}
617 Set the number of unreferenced segments to keep on disk before @code{hls_flags delete_segments}
618 deletes them. Increase this to allow continue clients to download segments which
619 were recently referenced in the playlist. Default value is 1, meaning segments older than
620 @code{hls_list_size+1} will be deleted.
622 @item hls_ts_options @var{options_list}
623 Set output format options using a :-separated list of key=value
624 parameters. Values containing @code{:} special characters must be
627 @item hls_wrap @var{wrap}
628 This is a deprecated option, you can use @code{hls_list_size}
629 and @code{hls_flags delete_segments} instead it
631 This option is useful to avoid to fill the disk with many segment
632 files, and limits the maximum number of segment files written to disk
636 @item hls_start_number_source
637 Start the playlist sequence number (@code{#EXT-X-MEDIA-SEQUENCE}) according to the specified source.
638 Unless @code{hls_flags single_file} is set, it also specifies source of starting sequence numbers of
639 segment and subtitle filenames. In any case, if @code{hls_flags append_list}
640 is set and read playlist sequence number is greater than the specified start sequence number,
641 then that value will be used as start value.
643 It accepts the following values:
647 @item generic (default)
648 Set the starting sequence numbers according to @var{start_number} option value.
651 The start number will be the seconds since epoch (1970-01-01 00:00:00)
654 The start number will be the microseconds since epoch (1970-01-01 00:00:00)
657 The start number will be based on the current date/time as YYYYmmddHHMMSS. e.g. 20161231235759.
661 @item start_number @var{number}
662 Start the playlist sequence number (@code{#EXT-X-MEDIA-SEQUENCE}) from the specified @var{number}
663 when @var{hls_start_number_source} value is @var{generic}. (This is the default case.)
664 Unless @code{hls_flags single_file} is set, it also specifies starting sequence numbers of segment and subtitle filenames.
667 @item hls_allow_cache @var{allowcache}
668 Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments.
670 @item hls_base_url @var{baseurl}
671 Append @var{baseurl} to every entry in the playlist.
672 Useful to generate playlists with absolute paths.
674 Note that the playlist sequence number must be unique for each segment
675 and it is not to be confused with the segment filename sequence number
676 which can be cyclic, for example if the @option{wrap} option is
679 @item hls_segment_filename @var{filename}
680 Set the segment filename. Unless @code{hls_flags single_file} is set,
681 @var{filename} is used as a string format with the segment number:
683 ffmpeg -i in.nut -hls_segment_filename 'file%03d.ts' out.m3u8
685 This example will produce the playlist, @file{out.m3u8}, and segment files:
686 @file{file000.ts}, @file{file001.ts}, @file{file002.ts}, etc.
688 @var{filename} may contain full path or relative path specification,
689 but only the file name part without any path info will be contained in the m3u8 segment list.
690 Should a relative path be specified, the path of the created segment
691 files will be relative to the current working directory.
692 When strftime_mkdir is set, the whole expanded value of @var{filename} will be written into the m3u8 segment list.
694 When @code{var_stream_map} is set with two or more variant streams, the
695 @var{filename} pattern must contain the string "%v", this string specifies
696 the position of variant stream index in the generated segment file names.
698 ffmpeg -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
699 -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" \
700 -hls_segment_filename 'file_%v_%03d.ts' out_%v.m3u8
702 This example will produce the playlists segment file sets:
703 @file{file_0_000.ts}, @file{file_0_001.ts}, @file{file_0_002.ts}, etc. and
704 @file{file_1_000.ts}, @file{file_1_001.ts}, @file{file_1_002.ts}, etc.
706 The string "%v" may be present in the filename or in the last directory name
707 containing the file, but only in one of them. (Additionally, %v may appear multiple times in the last
708 sub-directory or filename.) If the string %v is present in the directory name, then
709 sub-directories are created after expanding the directory name pattern. This
710 enables creation of segments corresponding to different variant streams in
713 ffmpeg -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
714 -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" \
715 -hls_segment_filename 'vs%v/file_%03d.ts' vs%v/out.m3u8
717 This example will produce the playlists segment file sets:
718 @file{vs0/file_000.ts}, @file{vs0/file_001.ts}, @file{vs0/file_002.ts}, etc. and
719 @file{vs1/file_000.ts}, @file{vs1/file_001.ts}, @file{vs1/file_002.ts}, etc.
722 Same as strftime option, will be deprecated.
725 Use strftime() on @var{filename} to expand the segment filename with localtime.
726 The segment number is also available in this mode, but to use it, you need to specify second_level_segment_index
727 hls_flag and %%d will be the specifier.
729 ffmpeg -i in.nut -strftime 1 -hls_segment_filename 'file-%Y%m%d-%s.ts' out.m3u8
731 This example will produce the playlist, @file{out.m3u8}, and segment files:
732 @file{file-20160215-1455569023.ts}, @file{file-20160215-1455569024.ts}, etc.
733 Note: On some systems/environments, the @code{%s} specifier is not available. See
734 @code{strftime()} documentation.
736 ffmpeg -i in.nut -strftime 1 -hls_flags second_level_segment_index -hls_segment_filename 'file-%Y%m%d-%%04d.ts' out.m3u8
738 This example will produce the playlist, @file{out.m3u8}, and segment files:
739 @file{file-20160215-0001.ts}, @file{file-20160215-0002.ts}, etc.
741 @item use_localtime_mkdir
742 Same as strftime_mkdir option, will be deprecated .
745 Used together with -strftime_mkdir, it will create all subdirectories which
746 is expanded in @var{filename}.
748 ffmpeg -i in.nut -strftime 1 -strftime_mkdir 1 -hls_segment_filename '%Y%m%d/file-%Y%m%d-%s.ts' out.m3u8
750 This example will create a directory 201560215 (if it does not exist), and then
751 produce the playlist, @file{out.m3u8}, and segment files:
752 @file{20160215/file-20160215-1455569023.ts}, @file{20160215/file-20160215-1455569024.ts}, etc.
755 ffmpeg -i in.nut -strftime 1 -strftime_mkdir 1 -hls_segment_filename '%Y/%m/%d/file-%Y%m%d-%s.ts' out.m3u8
757 This example will create a directory hierarchy 2016/02/15 (if any of them do not exist), and then
758 produce the playlist, @file{out.m3u8}, and segment files:
759 @file{2016/02/15/file-20160215-1455569023.ts}, @file{2016/02/15/file-20160215-1455569024.ts}, etc.
762 @item hls_key_info_file @var{key_info_file}
763 Use the information in @var{key_info_file} for segment encryption. The first
764 line of @var{key_info_file} specifies the key URI written to the playlist. The
765 key URL is used to access the encryption key during playback. The second line
766 specifies the path to the key file used to obtain the key during the encryption
767 process. The key file is read as a single packed array of 16 octets in binary
768 format. The optional third line specifies the initialization vector (IV) as a
769 hexadecimal string to be used instead of the segment sequence number (default)
770 for encryption. Changes to @var{key_info_file} will result in segment
771 encryption with the new key/IV and an entry in the playlist for the new key
772 URI/IV if @code{hls_flags periodic_rekey} is enabled.
774 Key info file format:
783 http://server/file.key
788 Example key file paths:
796 0123456789ABCDEF0123456789ABCDEF
799 Key info file example:
801 http://server/file.key
803 0123456789ABCDEF0123456789ABCDEF
806 Example shell script:
810 openssl rand 16 > file.key
811 echo $BASE_URL/file.key > file.keyinfo
812 echo file.key >> file.keyinfo
813 echo $(openssl rand -hex 16) >> file.keyinfo
814 ffmpeg -f lavfi -re -i testsrc -c:v h264 -hls_flags delete_segments \
815 -hls_key_info_file file.keyinfo out.m3u8
818 @item -hls_enc @var{enc}
819 Enable (1) or disable (0) the AES128 encryption.
820 When enabled every segment generated is encrypted and the encryption key
821 is saved as @var{playlist name}.key.
823 @item -hls_enc_key @var{key}
824 Hex-coded 16byte key to encrypt the segments, by default it
825 is randomly generated.
827 @item -hls_enc_key_url @var{keyurl}
828 If set, @var{keyurl} is prepended instead of @var{baseurl} to the key filename
831 @item -hls_enc_iv @var{iv}
832 Hex-coded 16byte initialization vector for every segment instead
833 of the autogenerated ones.
835 @item hls_segment_type @var{flags}
840 Output segment files in MPEG-2 Transport Stream format. This is
841 compatible with all HLS versions.
844 Output segment files in fragmented MP4 format, similar to MPEG-DASH.
845 fmp4 files may be used in HLS version 7 and above.
849 @item hls_fmp4_init_filename @var{filename}
850 Set filename to the fragment files header file, default filename is @file{init.mp4}.
852 @item hls_fmp4_init_resend
853 Resend init file after m3u8 file refresh every time, default is @var{0}.
855 When @code{var_stream_map} is set with two or more variant streams, the
856 @var{filename} pattern must contain the string "%v", this string specifies
857 the position of variant stream index in the generated init file names.
858 The string "%v" may be present in the filename or in the last directory name
859 containing the file. If the string is present in the directory name, then
860 sub-directories are created after expanding the directory name pattern. This
861 enables creation of init files corresponding to different variant streams in
864 @item hls_flags @var{flags}
869 If this flag is set, the muxer will store all segments in a single MPEG-TS
870 file, and will use byte ranges in the playlist. HLS playlists generated with
871 this way will have the version number 4.
874 ffmpeg -i in.nut -hls_flags single_file out.m3u8
876 Will produce the playlist, @file{out.m3u8}, and a single segment file,
879 @item delete_segments
880 Segment files removed from the playlist are deleted after a period of time
881 equal to the duration of the segment plus the duration of the playlist.
884 Append new segments into the end of old segment list,
885 and remove the @code{#EXT-X-ENDLIST} from the old segment list.
887 @item round_durations
888 Round the duration info in the playlist file segment info to integer
889 values, instead of using floating point.
892 Add the @code{#EXT-X-DISCONTINUITY} tag to the playlist, before the
893 first segment's information.
896 Do not append the @code{EXT-X-ENDLIST} tag at the end of the playlist.
899 The file specified by @code{hls_key_info_file} will be checked periodically and
900 detect updates to the encryption info. Be sure to replace this file atomically,
901 including the file containing the AES encryption key.
903 @item independent_segments
904 Add the @code{#EXT-X-INDEPENDENT-SEGMENTS} to playlists that has video segments
905 and when all the segments of that playlist are guaranteed to start with a Key frame.
908 Add the @code{#EXT-X-I-FRAMES-ONLY} to playlists that has video segments
909 and can play only I-frames in the @code{#EXT-X-BYTERANGE} mode.
912 Allow segments to start on frames other than keyframes. This improves
913 behavior on some players when the time between keyframes is inconsistent,
914 but may make things worse on others, and can cause some oddities during
915 seeking. This flag should be used with the @code{hls_time} option.
917 @item program_date_time
918 Generate @code{EXT-X-PROGRAM-DATE-TIME} tags.
920 @item second_level_segment_index
921 Makes it possible to use segment indexes as %%d in hls_segment_filename expression
922 besides date/time values when strftime is on.
923 To get fixed width numbers with trailing zeroes, %%0xd format is available where x is the required width.
925 @item second_level_segment_size
926 Makes it possible to use segment sizes (counted in bytes) as %%s in hls_segment_filename
927 expression besides date/time values when strftime is on.
928 To get fixed width numbers with trailing zeroes, %%0xs format is available where x is the required width.
930 @item second_level_segment_duration
931 Makes it possible to use segment duration (calculated in microseconds) as %%t in hls_segment_filename
932 expression besides date/time values when strftime is on.
933 To get fixed width numbers with trailing zeroes, %%0xt format is available where x is the required width.
936 ffmpeg -i sample.mpeg \
937 -f hls -hls_time 3 -hls_list_size 5 \
938 -hls_flags second_level_segment_index+second_level_segment_size+second_level_segment_duration \
939 -strftime 1 -strftime_mkdir 1 -hls_segment_filename "segment_%Y%m%d%H%M%S_%%04d_%%08s_%%013t.ts" stream.m3u8
941 This will produce segments like this:
942 @file{segment_20170102194334_0003_00122200_0000003000000.ts}, @file{segment_20170102194334_0004_00120072_0000003000000.ts} etc.
945 Write segment data to filename.tmp and rename to filename only once the segment is complete. A webserver
946 serving up segments can be configured to reject requests to *.tmp to prevent access to in-progress segments
947 before they have been added to the m3u8 playlist. This flag also affects how m3u8 playlist files are created.
948 If this flag is set, all playlist files will written into temporary file and renamed after they are complete, similarly as segments are handled.
949 But playlists with @code{file} protocol and with type (@code{hls_playlist_type}) other than @code{vod}
950 are always written into temporary file regardless of this flag. Master playlist files (@code{master_pl_name}), if any, with @code{file} protocol,
951 are always written into temporary file regardless of this flag if @code{master_pl_publish_rate} value is other than zero.
955 @item hls_playlist_type event
956 Emit @code{#EXT-X-PLAYLIST-TYPE:EVENT} in the m3u8 header. Forces
957 @option{hls_list_size} to 0; the playlist can only be appended to.
959 @item hls_playlist_type vod
960 Emit @code{#EXT-X-PLAYLIST-TYPE:VOD} in the m3u8 header. Forces
961 @option{hls_list_size} to 0; the playlist must not change.
964 Use the given HTTP method to create the hls files.
966 ffmpeg -re -i in.ts -f hls -method PUT http://example.com/live/out.m3u8
968 This example will upload all the mpegts segment files to the HTTP
969 server using the HTTP PUT method, and update the m3u8 files every
970 @code{refresh} times using the same method.
971 Note that the HTTP server must support the given method for uploading
974 @item http_user_agent
975 Override User-Agent field in HTTP header. Applicable only for HTTP output.
978 Map string which specifies how to group the audio, video and subtitle streams
979 into different variant streams. The variant stream groups are separated
981 Expected string format is like this "a:0,v:0 a:1,v:1 ....". Here a:, v:, s: are
982 the keys to specify audio, video and subtitle streams respectively.
983 Allowed values are 0 to 9 (limited just based on practical usage).
985 When there are two or more variant streams, the output filename pattern must
986 contain the string "%v", this string specifies the position of variant stream
987 index in the output media playlist filenames. The string "%v" may be present in
988 the filename or in the last directory name containing the file. If the string is
989 present in the directory name, then sub-directories are created after expanding
990 the directory name pattern. This enables creation of variant streams in
994 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
995 -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" \
996 http://example.com/live/out_%v.m3u8
998 This example creates two hls variant streams. The first variant stream will
999 contain video stream of bitrate 1000k and audio stream of bitrate 64k and the
1000 second variant stream will contain video stream of bitrate 256k and audio
1001 stream of bitrate 32k. Here, two media playlist with file names out_0.m3u8 and
1002 out_1.m3u8 will be created. If you want something meaningful text instead of indexes
1003 in result names, you may specify names for each or some of the variants
1004 as in the following example.
1008 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
1009 -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" \
1010 http://example.com/live/out_%v.m3u8
1013 This example creates two hls variant streams as in the previous one.
1014 But here, the two media playlist with file names out_my_hd.m3u8 and
1015 out_my_sd.m3u8 will be created.
1018 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k \
1019 -map 0:v -map 0:a -map 0:v -f hls -var_stream_map "v:0 a:0 v:1" \
1020 http://example.com/live/out_%v.m3u8
1022 This example creates three hls variant streams. The first variant stream will
1023 be a video only stream with video bitrate 1000k, the second variant stream will
1024 be an audio only stream with bitrate 64k and the third variant stream will be a
1025 video only stream with bitrate 256k. Here, three media playlist with file names
1026 out_0.m3u8, out_1.m3u8 and out_2.m3u8 will be created.
1028 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
1029 -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" \
1030 http://example.com/live/vs_%v/out.m3u8
1032 This example creates the variant streams in subdirectories. Here, the first
1033 media playlist is created at @file{http://example.com/live/vs_0/out.m3u8} and
1034 the second one at @file{http://example.com/live/vs_1/out.m3u8}.
1036 ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k -b:v:1 3000k \
1037 -map 0:a -map 0:a -map 0:v -map 0:v -f hls \
1038 -var_stream_map "a:0,agroup:aud_low a:1,agroup:aud_high v:0,agroup:aud_low v:1,agroup:aud_high" \
1039 -master_pl_name master.m3u8 \
1040 http://example.com/live/out_%v.m3u8
1042 This example creates two audio only and two video only variant streams. In
1043 addition to the #EXT-X-STREAM-INF tag for each variant stream in the master
1044 playlist, #EXT-X-MEDIA tag is also added for the two audio only variant streams
1045 and they are mapped to the two video only variant streams with audio group names
1046 'aud_low' and 'aud_high'.
1048 By default, a single hls variant containing all the encoded streams is created.
1051 ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k \
1052 -map 0:a -map 0:a -map 0:v -f hls \
1053 -var_stream_map "a:0,agroup:aud_low,default:yes a:1,agroup:aud_low v:0,agroup:aud_low" \
1054 -master_pl_name master.m3u8 \
1055 http://example.com/live/out_%v.m3u8
1057 This example creates two audio only and one video only variant streams. In
1058 addition to the #EXT-X-STREAM-INF tag for each variant stream in the master
1059 playlist, #EXT-X-MEDIA tag is also added for the two audio only variant streams
1060 and they are mapped to the one video only variant streams with audio group name
1061 'aud_low', and the audio group have default stat is NO or YES.
1063 By default, a single hls variant containing all the encoded streams is created.
1066 ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k \
1067 -map 0:a -map 0:a -map 0:v -f hls \
1068 -var_stream_map "a:0,agroup:aud_low,default:yes,language:ENG a:1,agroup:aud_low,language:CHN v:0,agroup:aud_low" \
1069 -master_pl_name master.m3u8 \
1070 http://example.com/live/out_%v.m3u8
1072 This example creates two audio only and one video only variant streams. In
1073 addition to the #EXT-X-STREAM-INF tag for each variant stream in the master
1074 playlist, #EXT-X-MEDIA tag is also added for the two audio only variant streams
1075 and they are mapped to the one video only variant streams with audio group name
1076 'aud_low', and the audio group have default stat is NO or YES, and one audio
1077 have and language is named ENG, the other audio language is named CHN.
1079 By default, a single hls variant containing all the encoded streams is created.
1082 ffmpeg -y -i input_with_subtitle.mkv \
1083 -b:v:0 5250k -c:v h264 -pix_fmt yuv420p -profile:v main -level 4.1 \
1085 -c:s webvtt -c:a mp2 -ar 48000 -ac 2 -map 0:v -map 0:a:0 -map 0:s:0 \
1086 -f hls -var_stream_map "v:0,a:0,s:0,sgroup:subtitle" \
1087 -master_pl_name master.m3u8 -t 300 -hls_time 10 -hls_init_time 4 -hls_list_size \
1088 10 -master_pl_publish_rate 10 -hls_flags \
1089 delete_segments+discont_start+split_by_time ./tmp/video.m3u8
1092 This example adds @code{#EXT-X-MEDIA} tag with @code{TYPE=SUBTITLES} in
1093 the master playlist with webvtt subtitle group name 'subtitle'. Please make sure
1094 the input file has one text subtitle stream at least.
1097 Map string which specifies different closed captions groups and their
1098 attributes. The closed captions stream groups are separated by space.
1099 Expected string format is like this
1100 "ccgroup:<group name>,instreamid:<INSTREAM-ID>,language:<language code> ....".
1101 'ccgroup' and 'instreamid' are mandatory attributes. 'language' is an optional
1103 The closed captions groups configured using this option are mapped to different
1104 variant streams by providing the same 'ccgroup' name in the
1105 @code{var_stream_map} string. If @code{var_stream_map} is not set, then the
1106 first available ccgroup in @code{cc_stream_map} is mapped to the output variant
1107 stream. The examples for these two use cases are given below.
1110 ffmpeg -re -i in.ts -b:v 1000k -b:a 64k -a53cc 1 -f hls \
1111 -cc_stream_map "ccgroup:cc,instreamid:CC1,language:en" \
1112 -master_pl_name master.m3u8 \
1113 http://example.com/live/out.m3u8
1115 This example adds @code{#EXT-X-MEDIA} tag with @code{TYPE=CLOSED-CAPTIONS} in
1116 the master playlist with group name 'cc', language 'en' (english) and
1117 INSTREAM-ID 'CC1'. Also, it adds @code{CLOSED-CAPTIONS} attribute with group
1118 name 'cc' for the output variant stream.
1120 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
1121 -a53cc:0 1 -a53cc:1 1\
1122 -map 0:v -map 0:a -map 0:v -map 0:a -f hls \
1123 -cc_stream_map "ccgroup:cc,instreamid:CC1,language:en ccgroup:cc,instreamid:CC2,language:sp" \
1124 -var_stream_map "v:0,a:0,ccgroup:cc v:1,a:1,ccgroup:cc" \
1125 -master_pl_name master.m3u8 \
1126 http://example.com/live/out_%v.m3u8
1128 This example adds two @code{#EXT-X-MEDIA} tags with @code{TYPE=CLOSED-CAPTIONS} in
1129 the master playlist for the INSTREAM-IDs 'CC1' and 'CC2'. Also, it adds
1130 @code{CLOSED-CAPTIONS} attribute with group name 'cc' for the two output variant
1133 @item master_pl_name
1134 Create HLS master playlist with the given name.
1137 ffmpeg -re -i in.ts -f hls -master_pl_name master.m3u8 http://example.com/live/out.m3u8
1139 This example creates HLS master playlist with name master.m3u8 and it is
1140 published at http://example.com/live/
1142 @item master_pl_publish_rate
1143 Publish master play list repeatedly every after specified number of segment intervals.
1146 ffmpeg -re -i in.ts -f hls -master_pl_name master.m3u8 \
1147 -hls_time 2 -master_pl_publish_rate 30 http://example.com/live/out.m3u8
1150 This example creates HLS master playlist with name master.m3u8 and keep
1151 publishing it repeatedly every after 30 segments i.e. every after 60s.
1153 @item http_persistent
1154 Use persistent HTTP connections. Applicable only for HTTP output.
1157 Set timeout for socket I/O operations. Applicable only for HTTP output.
1159 @item -ignore_io_errors
1160 Ignore IO errors during open, write and delete. Useful for long-duration runs with network output.
1163 Set custom HTTP headers, can override built in default headers. Applicable only for HTTP output.
1172 Microsoft's icon file format (ICO) has some strict limitations that should be noted:
1176 Size cannot exceed 256 pixels in any dimension
1179 Only BMP and PNG images can be stored
1182 If a BMP image is used, it must be one of the following pixel formats:
1184 BMP Bit Depth FFmpeg Pixel Format
1194 If a BMP image is used, it must use the BITMAPINFOHEADER DIB header
1197 If a PNG image is used, it must use the rgba pixel format
1205 The image file muxer writes video frames to image files.
1207 The output filenames are specified by a pattern, which can be used to
1208 produce sequentially numbered series of files.
1209 The pattern may contain the string "%d" or "%0@var{N}d", this string
1210 specifies the position of the characters representing a numbering in
1211 the filenames. If the form "%0@var{N}d" is used, the string
1212 representing the number in each filename is 0-padded to @var{N}
1213 digits. The literal character '%' can be specified in the pattern with
1216 If the pattern contains "%d" or "%0@var{N}d", the first filename of
1217 the file list specified will contain the number 1, all the following
1218 numbers will be sequential.
1220 The pattern may contain a suffix which is used to automatically
1221 determine the format of the image files to write.
1223 For example the pattern "img-%03d.bmp" will specify a sequence of
1224 filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ...,
1225 @file{img-010.bmp}, etc.
1226 The pattern "img%%-%d.jpg" will specify a sequence of filenames of the
1227 form @file{img%-1.jpg}, @file{img%-2.jpg}, ..., @file{img%-10.jpg},
1230 The image muxer supports the .Y.U.V image file format. This format is
1231 special in that that each image frame consists of three files, for
1232 each of the YUV420P components. To read or write this image file format,
1233 specify the name of the '.Y' file. The muxer will automatically open the
1234 '.U' and '.V' files as required.
1240 If set to 1, expand the filename with pts from pkt->pts.
1244 Start the sequence from the specified number. Default value is 1.
1247 If set to 1, the filename will always be interpreted as just a
1248 filename, not a pattern, and the corresponding file will be continuously
1249 overwritten with new images. Default value is 0.
1252 If set to 1, expand the filename with date and time information from
1253 @code{strftime()}. Default value is 0.
1255 @item protocol_opts @var{options_list}
1256 Set protocol options as a :-separated list of key=value parameters. Values
1257 containing the @code{:} special character must be escaped.
1261 @subsection Examples
1263 The following example shows how to use @command{ffmpeg} for creating a
1264 sequence of files @file{img-001.jpeg}, @file{img-002.jpeg}, ...,
1265 taking one image every second from the input video:
1267 ffmpeg -i in.avi -vsync cfr -r 1 -f image2 'img-%03d.jpeg'
1270 Note that with @command{ffmpeg}, if the format is not specified with the
1271 @code{-f} option and the output filename specifies an image file
1272 format, the image2 muxer is automatically selected, so the previous
1273 command can be written as:
1275 ffmpeg -i in.avi -vsync cfr -r 1 'img-%03d.jpeg'
1278 Note also that the pattern must not necessarily contain "%d" or
1279 "%0@var{N}d", for example to create a single image file
1280 @file{img.jpeg} from the start of the input video you can employ the command:
1282 ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg
1285 The @option{strftime} option allows you to expand the filename with
1286 date and time information. Check the documentation of
1287 the @code{strftime()} function for the syntax.
1289 For example to generate image files from the @code{strftime()}
1290 "%Y-%m-%d_%H-%M-%S" pattern, the following @command{ffmpeg} command
1293 ffmpeg -f v4l2 -r 1 -i /dev/video0 -f image2 -strftime 1 "%Y-%m-%d_%H-%M-%S.jpg"
1296 You can set the file name with current frame's PTS:
1298 ffmpeg -f v4l2 -r 1 -i /dev/video0 -copyts -f image2 -frame_pts true %d.jpg"
1301 A more complex example is to publish contents of your desktop directly to a
1302 WebDAV server every second:
1304 ffmpeg -f x11grab -framerate 1 -i :0.0 -q:v 6 -update 1 -protocol_opts method=PUT http://example.com/desktop.jpg
1309 Matroska container muxer.
1311 This muxer implements the matroska and webm container specs.
1313 @subsection Metadata
1315 The recognized metadata settings in this muxer are:
1319 Set title name provided to a single track. This gets mapped to
1320 the FileDescription element for a stream written as attachment.
1323 Specify the language of the track in the Matroska languages form.
1325 The language can be either the 3 letters bibliographic ISO-639-2 (ISO
1326 639-2/B) form (like "fre" for French), or a language code mixed with a
1327 country code for specialities in languages (like "fre-ca" for Canadian
1331 Set stereo 3D video layout of two views in a single video track.
1333 The following values are recognized:
1338 Both views are arranged side by side, Left-eye view is on the left
1340 Both views are arranged in top-bottom orientation, Left-eye view is at bottom
1342 Both views are arranged in top-bottom orientation, Left-eye view is on top
1343 @item checkerboard_rl
1344 Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first
1345 @item checkerboard_lr
1346 Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first
1347 @item row_interleaved_rl
1348 Each view is constituted by a row based interleaving, Right-eye view is first row
1349 @item row_interleaved_lr
1350 Each view is constituted by a row based interleaving, Left-eye view is first row
1351 @item col_interleaved_rl
1352 Both views are arranged in a column based interleaving manner, Right-eye view is first column
1353 @item col_interleaved_lr
1354 Both views are arranged in a column based interleaving manner, Left-eye view is first column
1355 @item anaglyph_cyan_red
1356 All frames are in anaglyph format viewable through red-cyan filters
1358 Both views are arranged side by side, Right-eye view is on the left
1359 @item anaglyph_green_magenta
1360 All frames are in anaglyph format viewable through green-magenta filters
1362 Both eyes laced in one Block, Left-eye view is first
1364 Both eyes laced in one Block, Right-eye view is first
1368 For example a 3D WebM clip can be created using the following command line:
1370 ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm
1375 This muxer supports the following options:
1378 @item reserve_index_space
1379 By default, this muxer writes the index for seeking (called cues in Matroska
1380 terms) at the end of the file, because it cannot know in advance how much space
1381 to leave for the index at the beginning of the file. However for some use cases
1382 -- e.g. streaming where seeking is possible but slow -- it is useful to put the
1383 index at the beginning of the file.
1385 If this option is set to a non-zero value, the muxer will reserve a given amount
1386 of space in the file header and then try to write the cues there when the muxing
1387 finishes. If the reserved space does not suffice, no Cues will be written, the
1388 file will be finalized and writing the trailer will return an error.
1389 A safe size for most use cases should be about 50kB per hour of video.
1391 Note that cues are only written if the output is seekable and this option will
1392 have no effect if it is not.
1394 This option controls how the FlagDefault of the output tracks will be set.
1395 It influences which tracks players should play by default. The default mode
1399 In this mode, for each type of track (audio, video or subtitle), if there is
1400 a track with disposition default of this type, then the first such track
1401 (i.e. the one with the lowest index) will be marked as default; if no such
1402 track exists, the first track of this type will be marked as default instead
1403 (if existing). This ensures that the default flag is set in a sensible way even
1404 if the input originated from containers that lack the concept of default tracks.
1406 This mode is the same as infer except that if no subtitle track with
1407 disposition default exists, no subtitle track will be marked as default.
1409 In this mode the FlagDefault is set if and only if the AV_DISPOSITION_DEFAULT
1410 flag is set in the disposition of the corresponding stream.
1419 This is a variant of the @ref{hash} muxer. Unlike that muxer, it
1420 defaults to using the MD5 hash function.
1422 @subsection Examples
1424 To compute the MD5 hash of the input converted to raw
1425 audio and video, and store it in the file @file{out.md5}:
1427 ffmpeg -i INPUT -f md5 out.md5
1430 You can print the MD5 to stdout with the command:
1432 ffmpeg -i INPUT -f md5 -
1435 See also the @ref{hash} and @ref{framemd5} muxers.
1437 @section mov, mp4, ismv
1439 MOV/MP4/ISMV (Smooth Streaming) muxer.
1441 The mov/mp4/ismv muxer supports fragmentation. Normally, a MOV/MP4
1442 file has all the metadata about all packets stored in one location
1443 (written at the end of the file, it can be moved to the start for
1444 better playback by adding @var{faststart} to the @var{movflags}, or
1445 using the @command{qt-faststart} tool). A fragmented
1446 file consists of a number of fragments, where packets and metadata
1447 about these packets are stored together. Writing a fragmented
1448 file has the advantage that the file is decodable even if the
1449 writing is interrupted (while a normal MOV/MP4 is undecodable if
1450 it is not properly finished), and it requires less memory when writing
1451 very long files (since writing normal MOV/MP4 files stores info about
1452 every single packet in memory until the file is closed). The downside
1453 is that it is less compatible with other applications.
1457 Fragmentation is enabled by setting one of the AVOptions that define
1458 how to cut the file into fragments:
1461 @item -moov_size @var{bytes}
1462 Reserves space for the moov atom at the beginning of the file instead of placing the
1463 moov atom at the end. If the space reserved is insufficient, muxing will fail.
1464 @item -movflags frag_keyframe
1465 Start a new fragment at each video keyframe.
1466 @item -frag_duration @var{duration}
1467 Create fragments that are @var{duration} microseconds long.
1468 @item -frag_size @var{size}
1469 Create fragments that contain up to @var{size} bytes of payload data.
1470 @item -movflags frag_custom
1471 Allow the caller to manually choose when to cut fragments, by
1472 calling @code{av_write_frame(ctx, NULL)} to write a fragment with
1473 the packets written so far. (This is only useful with other
1474 applications integrating libavformat, not from @command{ffmpeg}.)
1475 @item -min_frag_duration @var{duration}
1476 Don't create fragments that are shorter than @var{duration} microseconds long.
1479 If more than one condition is specified, fragments are cut when
1480 one of the specified conditions is fulfilled. The exception to this is
1481 @code{-min_frag_duration}, which has to be fulfilled for any of the other
1482 conditions to apply.
1484 Additionally, the way the output file is written can be adjusted
1485 through a few other options:
1488 @item -movflags empty_moov
1489 Write an initial moov atom directly at the start of the file, without
1490 describing any samples in it. Generally, an mdat/moov pair is written
1491 at the start of the file, as a normal MOV/MP4 file, containing only
1492 a short portion of the file. With this option set, there is no initial
1493 mdat atom, and the moov atom only describes the tracks but has
1496 This option is implicitly set when writing ismv (Smooth Streaming) files.
1497 @item -movflags separate_moof
1498 Write a separate moof (movie fragment) atom for each track. Normally,
1499 packets for all tracks are written in a moof atom (which is slightly
1500 more efficient), but with this option set, the muxer writes one moof/mdat
1501 pair for each track, making it easier to separate tracks.
1503 This option is implicitly set when writing ismv (Smooth Streaming) files.
1504 @item -movflags skip_sidx
1505 Skip writing of sidx atom. When bitrate overhead due to sidx atom is high,
1506 this option could be used for cases where sidx atom is not mandatory.
1507 When global_sidx flag is enabled, this option will be ignored.
1508 @item -movflags faststart
1509 Run a second pass moving the index (moov atom) to the beginning of the file.
1510 This operation can take a while, and will not work in various situations such
1511 as fragmented output, thus it is not enabled by default.
1512 @item -movflags rtphint
1513 Add RTP hinting tracks to the output file.
1514 @item -movflags disable_chpl
1515 Disable Nero chapter markers (chpl atom). Normally, both Nero chapters
1516 and a QuickTime chapter track are written to the file. With this option
1517 set, only the QuickTime chapter track will be written. Nero chapters can
1518 cause failures when the file is reprocessed with certain tagging programs, like
1519 mp3Tag 2.61a and iTunes 11.3, most likely other versions are affected as well.
1520 @item -movflags omit_tfhd_offset
1521 Do not write any absolute base_data_offset in tfhd atoms. This avoids
1522 tying fragments to absolute byte positions in the file/streams.
1523 @item -movflags default_base_moof
1524 Similarly to the omit_tfhd_offset, this flag avoids writing the
1525 absolute base_data_offset field in tfhd atoms, but does so by using
1526 the new default-base-is-moof flag instead. This flag is new from
1527 14496-12:2012. This may make the fragments easier to parse in certain
1528 circumstances (avoiding basing track fragment location calculations
1529 on the implicit end of the previous track fragment).
1531 Specify @code{on} to force writing a timecode track, @code{off} to disable it
1532 and @code{auto} to write a timecode track only for mov and mp4 output (default).
1533 @item -movflags negative_cts_offsets
1534 Enables utilization of version 1 of the CTTS box, in which the CTS offsets can
1535 be negative. This enables the initial sample to have DTS/CTS of zero, and
1536 reduces the need for edit lists for some cases such as video tracks with
1537 B-frames. Additionally, eases conformance with the DASH-IF interoperability
1540 This option is implicitly set when writing ismv (Smooth Streaming) files.
1542 Write producer time reference box (PRFT) with a specified time source for the
1543 NTP field in the PRFT box. Set value as @samp{wallclock} to specify timesource
1544 as wallclock time and @samp{pts} to specify timesource as input packets' PTS
1547 Setting value to @samp{pts} is applicable only for a live encoding use case,
1548 where PTS values are set as as wallclock time at the source. For example, an
1549 encoding use case with decklink capture source where @option{video_pts} and
1550 @option{audio_pts} are set to @samp{abs_wallclock}.
1555 Smooth Streaming content can be pushed in real time to a publishing
1556 point on IIS with this muxer. Example:
1558 ffmpeg -re @var{<normal input/transcoding options>} -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1)
1563 The MP3 muxer writes a raw MP3 stream with the following optional features:
1566 An ID3v2 metadata header at the beginning (enabled by default). Versions 2.3 and
1567 2.4 are supported, the @code{id3v2_version} private option controls which one is
1568 used (3 or 4). Setting @code{id3v2_version} to 0 disables the ID3v2 header
1571 The muxer supports writing attached pictures (APIC frames) to the ID3v2 header.
1572 The pictures are supplied to the muxer in form of a video stream with a single
1573 packet. There can be any number of those streams, each will correspond to a
1574 single APIC frame. The stream metadata tags @var{title} and @var{comment} map
1575 to APIC @var{description} and @var{picture type} respectively. See
1576 @url{http://id3.org/id3v2.4.0-frames} for allowed picture types.
1578 Note that the APIC frames must be written at the beginning, so the muxer will
1579 buffer the audio frames until it gets all the pictures. It is therefore advised
1580 to provide the pictures as soon as possible to avoid excessive buffering.
1583 A Xing/LAME frame right after the ID3v2 header (if present). It is enabled by
1584 default, but will be written only if the output is seekable. The
1585 @code{write_xing} private option can be used to disable it. The frame contains
1586 various information that may be useful to the decoder, like the audio duration
1590 A legacy ID3v1 tag at the end of the file (disabled by default). It may be
1591 enabled with the @code{write_id3v1} private option, but as its capabilities are
1592 very limited, its usage is not recommended.
1597 Write an mp3 with an ID3v2.3 header and an ID3v1 footer:
1599 ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3
1602 To attach a picture to an mp3 file select both the audio and the picture stream
1605 ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1
1606 -metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3
1609 Write a "clean" MP3 without any extra features:
1611 ffmpeg -i input.wav -write_xing 0 -id3v2_version 0 out.mp3
1616 MPEG transport stream muxer.
1618 This muxer implements ISO 13818-1 and part of ETSI EN 300 468.
1620 The recognized metadata settings in mpegts muxer are @code{service_provider}
1621 and @code{service_name}. If they are not set the default for
1622 @code{service_provider} is @samp{FFmpeg} and the default for
1623 @code{service_name} is @samp{Service01}.
1627 The muxer options are:
1630 @item mpegts_transport_stream_id @var{integer}
1631 Set the @samp{transport_stream_id}. This identifies a transponder in DVB.
1632 Default is @code{0x0001}.
1634 @item mpegts_original_network_id @var{integer}
1635 Set the @samp{original_network_id}. This is unique identifier of a
1636 network in DVB. Its main use is in the unique identification of a service
1637 through the path @samp{Original_Network_ID, Transport_Stream_ID}. Default
1640 @item mpegts_service_id @var{integer}
1641 Set the @samp{service_id}, also known as program in DVB. Default is
1644 @item mpegts_service_type @var{integer}
1645 Set the program @samp{service_type}. Default is @code{digital_tv}.
1646 Accepts the following options:
1649 Any hexadecimal value between @code{0x01} and @code{0xff} as defined in
1654 Digital Radio service.
1657 @item advanced_codec_digital_radio
1658 Advanced Codec Digital Radio service.
1659 @item mpeg2_digital_hdtv
1660 MPEG2 Digital HDTV service.
1661 @item advanced_codec_digital_sdtv
1662 Advanced Codec Digital SDTV service.
1663 @item advanced_codec_digital_hdtv
1664 Advanced Codec Digital HDTV service.
1667 @item mpegts_pmt_start_pid @var{integer}
1668 Set the first PID for PMTs. Default is @code{0x1000}, minimum is @code{0x0020},
1669 maximum is @code{0x1ffa}. This option has no effect in m2ts mode where the PMT
1670 PID is fixed @code{0x0100}.
1672 @item mpegts_start_pid @var{integer}
1673 Set the first PID for elementary streams. Default is @code{0x0100}, minimum is
1674 @code{0x0020}, maximum is @code{0x1ffa}. This option has no effect in m2ts mode
1675 where the elementary stream PIDs are fixed.
1677 @item mpegts_m2ts_mode @var{boolean}
1678 Enable m2ts mode if set to @code{1}. Default value is @code{-1} which
1681 @item muxrate @var{integer}
1682 Set a constant muxrate. Default is VBR.
1684 @item pes_payload_size @var{integer}
1685 Set minimum PES packet payload in bytes. Default is @code{2930}.
1687 @item mpegts_flags @var{flags}
1688 Set mpegts flags. Accepts the following options:
1690 @item resend_headers
1691 Reemit PAT/PMT before writing the next packet.
1693 Use LATM packetization for AAC.
1694 @item pat_pmt_at_frames
1695 Reemit PAT and PMT at each video frame.
1697 Conform to System B (DVB) instead of System A (ATSC).
1698 @item initial_discontinuity
1699 Mark the initial packet of each stream as discontinuity.
1702 @item mpegts_copyts @var{boolean}
1703 Preserve original timestamps, if value is set to @code{1}. Default value
1704 is @code{-1}, which results in shifting timestamps so that they start from 0.
1706 @item omit_video_pes_length @var{boolean}
1707 Omit the PES packet length for video packets. Default is @code{1} (true).
1709 @item pcr_period @var{integer}
1710 Override the default PCR retransmission time in milliseconds. Default is
1711 @code{-1} which means that the PCR interval will be determined automatically:
1712 20 ms is used for CBR streams, the highest multiple of the frame duration which
1713 is less than 100 ms is used for VBR streams.
1715 @item pat_period @var{duration}
1716 Maximum time in seconds between PAT/PMT tables. Default is @code{0.1}.
1718 @item sdt_period @var{duration}
1719 Maximum time in seconds between SDT tables. Default is @code{0.5}.
1721 @item tables_version @var{integer}
1722 Set PAT, PMT and SDT version (default @code{0}, valid values are from 0 to 31, inclusively).
1723 This option allows updating stream structure so that standard consumer may
1724 detect the change. To do so, reopen output @code{AVFormatContext} (in case of API
1725 usage) or restart @command{ffmpeg} instance, cyclically changing
1726 @option{tables_version} value:
1729 ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
1730 ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
1732 ffmpeg -i source3.ts -codec copy -f mpegts -tables_version 31 udp://1.1.1.1:1111
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
1742 ffmpeg -i file.mpg -c copy \
1743 -mpegts_original_network_id 0x1122 \
1744 -mpegts_transport_stream_id 0x3344 \
1745 -mpegts_service_id 0x5566 \
1746 -mpegts_pmt_start_pid 0x1500 \
1747 -mpegts_start_pid 0x150 \
1748 -metadata service_provider="Some provider" \
1749 -metadata service_name="Some Channel" \
1753 @section mxf, mxf_d10, mxf_opatom
1759 The muxer options are:
1762 @item store_user_comments @var{bool}
1763 Set if user comments should be stored if available or never.
1764 IRT D-10 does not allow user comments. The default is thus to write them for
1765 mxf and mxf_opatom but not for mxf_d10
1772 This muxer does not generate any output file, it is mainly useful for
1773 testing or benchmarking purposes.
1775 For example to benchmark decoding with @command{ffmpeg} you can use the
1778 ffmpeg -benchmark -i INPUT -f null out.null
1781 Note that the above command does not read or write the @file{out.null}
1782 file, but specifying the output file is required by the @command{ffmpeg}
1785 Alternatively you can write the command as:
1787 ffmpeg -benchmark -i INPUT -f null -
1793 @item -syncpoints @var{flags}
1794 Change the syncpoint usage in nut:
1796 @item @var{default} use the normal low-overhead seeking aids.
1797 @item @var{none} do not use the syncpoints at all, reducing the overhead but making the stream non-seekable;
1798 Use of this option is not recommended, as the resulting files are very damage
1799 sensitive and seeking is not possible. Also in general the overhead from
1800 syncpoints is negligible. Note, -@code{write_index} 0 can be used to disable
1801 all growing data tables, allowing to mux endless streams with limited memory
1802 and without these disadvantages.
1803 @item @var{timestamped} extend the syncpoint with a wallclock field.
1805 The @var{none} and @var{timestamped} flags are experimental.
1806 @item -write_index @var{bool}
1807 Write index at the end, the default is to write an index.
1811 ffmpeg -i INPUT -f_strict experimental -syncpoints none - | processor
1816 Ogg container muxer.
1819 @item -page_duration @var{duration}
1820 Preferred page duration, in microseconds. The muxer will attempt to create
1821 pages that are approximately @var{duration} microseconds long. This allows the
1822 user to compromise between seek granularity and container overhead. The default
1823 is 1 second. A value of 0 will fill all segments, making pages as large as
1824 possible. A value of 1 will effectively use 1 packet-per-page in most
1825 situations, giving a small seek granularity at the cost of additional container
1827 @item -serial_offset @var{value}
1828 Serial value from which to set the streams serial number.
1829 Setting it to different and sufficiently large values ensures that the produced
1830 ogg files can be safely chained.
1835 @section segment, stream_segment, ssegment
1837 Basic stream segmenter.
1839 This muxer outputs streams to a number of separate files of nearly
1840 fixed duration. Output filename pattern can be set in a fashion
1841 similar to @ref{image2}, or by using a @code{strftime} template if
1842 the @option{strftime} option is enabled.
1844 @code{stream_segment} is a variant of the muxer used to write to
1845 streaming output formats, i.e. which do not require global headers,
1846 and is recommended for outputting e.g. to MPEG transport stream segments.
1847 @code{ssegment} is a shorter alias for @code{stream_segment}.
1849 Every segment starts with a keyframe of the selected reference stream,
1850 which is set through the @option{reference_stream} option.
1852 Note that if you want accurate splitting for a video file, you need to
1853 make the input key frames correspond to the exact splitting times
1854 expected by the segmenter, or the segment muxer will start the new
1855 segment with the key frame found next after the specified start
1858 The segment muxer works best with a single constant frame rate video.
1860 Optionally it can generate a list of the created segments, by setting
1861 the option @var{segment_list}. The list type is specified by the
1862 @var{segment_list_type} option. The entry filenames in the segment
1863 list are set by default to the basename of the corresponding segment
1866 See also the @ref{hls} muxer, which provides a more specific
1867 implementation for HLS segmentation.
1871 The segment muxer supports the following options:
1874 @item increment_tc @var{1|0}
1875 if set to @code{1}, increment timecode between each segment
1876 If this is selected, the input need to have
1877 a timecode in the first video stream. Default value is
1880 @item reference_stream @var{specifier}
1881 Set the reference stream, as specified by the string @var{specifier}.
1882 If @var{specifier} is set to @code{auto}, the reference is chosen
1883 automatically. Otherwise it must be a stream specifier (see the ``Stream
1884 specifiers'' chapter in the ffmpeg manual) which specifies the
1885 reference stream. The default value is @code{auto}.
1887 @item segment_format @var{format}
1888 Override the inner container format, by default it is guessed by the filename
1891 @item segment_format_options @var{options_list}
1892 Set output format options using a :-separated list of key=value
1893 parameters. Values containing the @code{:} special character must be
1896 @item segment_list @var{name}
1897 Generate also a listfile named @var{name}. If not specified no
1898 listfile is generated.
1900 @item segment_list_flags @var{flags}
1901 Set flags affecting the segment list generation.
1903 It currently supports the following flags:
1906 Allow caching (only affects M3U8 list files).
1909 Allow live-friendly file generation.
1912 @item segment_list_size @var{size}
1913 Update the list file so that it contains at most @var{size}
1914 segments. If 0 the list file will contain all the segments. Default
1917 @item segment_list_entry_prefix @var{prefix}
1918 Prepend @var{prefix} to each entry. Useful to generate absolute paths.
1919 By default no prefix is applied.
1921 @item segment_list_type @var{type}
1922 Select the listing format.
1924 The following values are recognized:
1927 Generate a flat list for the created segments, one segment per line.
1930 Generate a list for the created segments, one segment per line,
1931 each line matching the format (comma-separated values):
1933 @var{segment_filename},@var{segment_start_time},@var{segment_end_time}
1936 @var{segment_filename} is the name of the output file generated by the
1937 muxer according to the provided pattern. CSV escaping (according to
1938 RFC4180) is applied if required.
1940 @var{segment_start_time} and @var{segment_end_time} specify
1941 the segment start and end time expressed in seconds.
1943 A list file with the suffix @code{".csv"} or @code{".ext"} will
1944 auto-select this format.
1946 @samp{ext} is deprecated in favor or @samp{csv}.
1949 Generate an ffconcat file for the created segments. The resulting file
1950 can be read using the FFmpeg @ref{concat} demuxer.
1952 A list file with the suffix @code{".ffcat"} or @code{".ffconcat"} will
1953 auto-select this format.
1956 Generate an extended M3U8 file, version 3, compliant with
1957 @url{http://tools.ietf.org/id/draft-pantos-http-live-streaming}.
1959 A list file with the suffix @code{".m3u8"} will auto-select this format.
1962 If not specified the type is guessed from the list file name suffix.
1964 @item segment_time @var{time}
1965 Set segment duration to @var{time}, the value must be a duration
1966 specification. Default value is "2". See also the
1967 @option{segment_times} option.
1969 Note that splitting may not be accurate, unless you force the
1970 reference stream key-frames at the given time. See the introductory
1971 notice and the examples below.
1973 @item segment_atclocktime @var{1|0}
1974 If set to "1" split at regular clock time intervals starting from 00:00
1975 o'clock. The @var{time} value specified in @option{segment_time} is
1976 used for setting the length of the splitting interval.
1978 For example with @option{segment_time} set to "900" this makes it possible
1979 to create files at 12:00 o'clock, 12:15, 12:30, etc.
1981 Default value is "0".
1983 @item segment_clocktime_offset @var{duration}
1984 Delay the segment splitting times with the specified duration when using
1985 @option{segment_atclocktime}.
1987 For example with @option{segment_time} set to "900" and
1988 @option{segment_clocktime_offset} set to "300" this makes it possible to
1989 create files at 12:05, 12:20, 12:35, etc.
1991 Default value is "0".
1993 @item segment_clocktime_wrap_duration @var{duration}
1994 Force the segmenter to only start a new segment if a packet reaches the muxer
1995 within the specified duration after the segmenting clock time. This way you
1996 can make the segmenter more resilient to backward local time jumps, such as
1997 leap seconds or transition to standard time from daylight savings time.
1999 Default is the maximum possible duration which means starting a new segment
2000 regardless of the elapsed time since the last clock time.
2002 @item segment_time_delta @var{delta}
2003 Specify the accuracy time when selecting the start time for a
2004 segment, expressed as a duration specification. Default value is "0".
2006 When delta is specified a key-frame will start a new segment if its
2007 PTS satisfies the relation:
2009 PTS >= start_time - time_delta
2012 This option is useful when splitting video content, which is always
2013 split at GOP boundaries, in case a key frame is found just before the
2014 specified split time.
2016 In particular may be used in combination with the @file{ffmpeg} option
2017 @var{force_key_frames}. The key frame times specified by
2018 @var{force_key_frames} may not be set accurately because of rounding
2019 issues, with the consequence that a key frame time may result set just
2020 before the specified time. For constant frame rate videos a value of
2021 1/(2*@var{frame_rate}) should address the worst case mismatch between
2022 the specified time and the time set by @var{force_key_frames}.
2024 @item segment_times @var{times}
2025 Specify a list of split points. @var{times} contains a list of comma
2026 separated duration specifications, in increasing order. See also
2027 the @option{segment_time} option.
2029 @item segment_frames @var{frames}
2030 Specify a list of split video frame numbers. @var{frames} contains a
2031 list of comma separated integer numbers, in increasing order.
2033 This option specifies to start a new segment whenever a reference
2034 stream key frame is found and the sequential number (starting from 0)
2035 of the frame is greater or equal to the next value in the list.
2037 @item segment_wrap @var{limit}
2038 Wrap around segment index once it reaches @var{limit}.
2040 @item segment_start_number @var{number}
2041 Set the sequence number of the first segment. Defaults to @code{0}.
2043 @item strftime @var{1|0}
2044 Use the @code{strftime} function to define the name of the new
2045 segments to write. If this is selected, the output segment name must
2046 contain a @code{strftime} function template. Default value is
2049 @item break_non_keyframes @var{1|0}
2050 If enabled, allow segments to start on frames other than keyframes. This
2051 improves behavior on some players when the time between keyframes is
2052 inconsistent, but may make things worse on others, and can cause some oddities
2053 during seeking. Defaults to @code{0}.
2055 @item reset_timestamps @var{1|0}
2056 Reset timestamps at the beginning of each segment, so that each segment
2057 will start with near-zero timestamps. It is meant to ease the playback
2058 of the generated segments. May not work with some combinations of
2059 muxers/codecs. It is set to @code{0} by default.
2061 @item initial_offset @var{offset}
2062 Specify timestamp offset to apply to the output packet timestamps. The
2063 argument must be a time duration specification, and defaults to 0.
2065 @item write_empty_segments @var{1|0}
2066 If enabled, write an empty segment if there are no packets during the period a
2067 segment would usually span. Otherwise, the segment will be filled with the next
2068 packet written. Defaults to @code{0}.
2071 Make sure to require a closed GOP when encoding and to set the GOP
2072 size to fit your segment time constraint.
2074 @subsection Examples
2078 Remux the content of file @file{in.mkv} to a list of segments
2079 @file{out-000.nut}, @file{out-001.nut}, etc., and write the list of
2080 generated segments to @file{out.list}:
2082 ffmpeg -i in.mkv -codec hevc -flags +cgop -g 60 -map 0 -f segment -segment_list out.list out%03d.nut
2086 Segment input and set output format options for the output segments:
2088 ffmpeg -i in.mkv -f segment -segment_time 10 -segment_format_options movflags=+faststart out%03d.mp4
2092 Segment the input file according to the split points specified by the
2093 @var{segment_times} option:
2095 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
2099 Use the @command{ffmpeg} @option{force_key_frames}
2100 option to force key frames in the input at the specified location, together
2101 with the segment option @option{segment_time_delta} to account for
2102 possible roundings operated when setting key frame times.
2104 ffmpeg -i in.mkv -force_key_frames 1,2,3,5,8,13,21 -codec:v mpeg4 -codec:a pcm_s16le -map 0 \
2105 -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 -segment_time_delta 0.05 out%03d.nut
2107 In order to force key frames on the input file, transcoding is
2111 Segment the input file by splitting the input file according to the
2112 frame numbers sequence specified with the @option{segment_frames} option:
2114 ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_frames 100,200,300,500,800 out%03d.nut
2118 Convert the @file{in.mkv} to TS segments using the @code{libx264}
2119 and @code{aac} encoders:
2121 ffmpeg -i in.mkv -map 0 -codec:v libx264 -codec:a aac -f ssegment -segment_list out.list out%03d.ts
2125 Segment the input file, and create an M3U8 live playlist (can be used
2126 as live HLS source):
2128 ffmpeg -re -i in.mkv -codec copy -map 0 -f segment -segment_list playlist.m3u8 \
2129 -segment_list_flags +live -segment_time 10 out%03d.mkv
2133 @section smoothstreaming
2135 Smooth Streaming muxer generates a set of files (Manifest, chunks) suitable for serving with conventional web server.
2139 Specify the number of fragments kept in the manifest. Default 0 (keep all).
2141 @item extra_window_size
2142 Specify the number of fragments kept outside of the manifest before removing from disk. Default 5.
2144 @item lookahead_count
2145 Specify the number of lookahead fragments. Default 2.
2147 @item min_frag_duration
2148 Specify the minimum fragment duration (in microseconds). Default 5000000.
2150 @item remove_at_exit
2151 Specify whether to remove all fragments when finished. Default 0 (do not remove).
2158 Per stream hash testing format.
2160 This muxer computes and prints a cryptographic hash of all the input frames,
2161 on a per-stream basis. This can be used for equality checks without having
2162 to do a complete binary comparison.
2164 By default audio frames are converted to signed 16-bit raw audio and
2165 video frames to raw video before computing the hash, but the output
2166 of explicit conversions to other codecs can also be used. Timestamps
2167 are ignored. It uses the SHA-256 cryptographic hash function by default,
2168 but supports several other algorithms.
2170 The output of the muxer consists of one line per stream of the form:
2171 @var{streamindex},@var{streamtype},@var{algo}=@var{hash}, where
2172 @var{streamindex} is the index of the mapped stream, @var{streamtype} is a
2173 single character indicating the type of stream, @var{algo} is a short string
2174 representing the hash function used, and @var{hash} is a hexadecimal number
2175 representing the computed hash.
2178 @item hash @var{algorithm}
2179 Use the cryptographic hash function specified by the string @var{algorithm}.
2180 Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
2181 @code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
2182 @code{SHA224}, @code{SHA256} (default), @code{SHA512/224}, @code{SHA512/256},
2183 @code{SHA384}, @code{SHA512}, @code{CRC32} and @code{adler32}.
2187 @subsection Examples
2189 To compute the SHA-256 hash of the input converted to raw audio and
2190 video, and store it in the file @file{out.sha256}:
2192 ffmpeg -i INPUT -f streamhash out.sha256
2195 To print an MD5 hash to stdout use the command:
2197 ffmpeg -i INPUT -f streamhash -hash md5 -
2200 See also the @ref{hash} and @ref{framehash} muxers.
2205 The fifo pseudo-muxer allows the separation of encoding and muxing by using
2206 first-in-first-out queue and running the actual muxer in a separate thread. This
2207 is especially useful in combination with the @ref{tee} muxer and can be used to
2208 send data to several destinations with different reliability/writing speed/latency.
2210 API users should be aware that callback functions (interrupt_callback,
2211 io_open and io_close) used within its AVFormatContext must be thread-safe.
2213 The behavior of the fifo muxer if the queue fills up or if the output fails is
2219 output can be transparently restarted with configurable delay between retries
2220 based on real time or time of the processed stream.
2223 encoding can be blocked during temporary failure, or continue transparently
2224 dropping packets in case fifo queue fills up.
2231 Specify the format name. Useful if it cannot be guessed from the
2235 Specify size of the queue (number of packets). Default value is 60.
2238 Specify format options for the underlying muxer. Muxer options can be specified
2239 as a list of @var{key}=@var{value} pairs separated by ':'.
2241 @item drop_pkts_on_overflow @var{bool}
2242 If set to 1 (true), in case the fifo queue fills up, packets will be dropped
2243 rather than blocking the encoder. This makes it possible to continue streaming without
2244 delaying the input, at the cost of omitting part of the stream. By default
2245 this option is set to 0 (false), so in such cases the encoder will be blocked
2246 until the muxer processes some of the packets and none of them is lost.
2248 @item attempt_recovery @var{bool}
2249 If failure occurs, attempt to recover the output. This is especially useful
2250 when used with network output, since it makes it possible to restart streaming transparently.
2251 By default this option is set to 0 (false).
2253 @item max_recovery_attempts
2254 Sets maximum number of successive unsuccessful recovery attempts after which
2255 the output fails permanently. By default this option is set to 0 (unlimited).
2257 @item recovery_wait_time @var{duration}
2258 Waiting time before the next recovery attempt after previous unsuccessful
2259 recovery attempt. Default value is 5 seconds.
2261 @item recovery_wait_streamtime @var{bool}
2262 If set to 0 (false), the real time is used when waiting for the recovery
2263 attempt (i.e. the recovery will be attempted after at least
2264 recovery_wait_time seconds).
2265 If set to 1 (true), the time of the processed stream is taken into account
2266 instead (i.e. the recovery will be attempted after at least @var{recovery_wait_time}
2267 seconds of the stream is omitted).
2268 By default, this option is set to 0 (false).
2270 @item recover_any_error @var{bool}
2271 If set to 1 (true), recovery will be attempted regardless of type of the error
2272 causing the failure. By default this option is set to 0 (false) and in case of
2273 certain (usually permanent) errors the recovery is not attempted even when
2274 @var{attempt_recovery} is set to 1.
2276 @item restart_with_keyframe @var{bool}
2277 Specify whether to wait for the keyframe after recovering from
2278 queue overflow or failure. This option is set to 0 (false) by default.
2280 @item timeshift @var{duration}
2281 Buffer the specified amount of packets and delay writing the output. Note that
2282 @var{queue_size} must be big enough to store the packets for timeshift. At the
2283 end of the input the fifo buffer is flushed at realtime speed.
2287 @subsection Examples
2292 Stream something to rtmp server, continue processing the stream at real-time
2293 rate even in case of temporary failure (network outage) and attempt to recover
2294 streaming every second indefinitely.
2296 ffmpeg -re -i ... -c:v libx264 -c:a aac -f fifo -fifo_format flv -map 0:v -map 0:a
2297 -drop_pkts_on_overflow 1 -attempt_recovery 1 -recovery_wait_time 1 rtmp://example.com/live/stream_name
2305 The tee muxer can be used to write the same data to several outputs, such as files or streams.
2306 It can be used, for example, to stream a video over a network and save it to disk at the same time.
2308 It is different from specifying several outputs to the @command{ffmpeg}
2309 command-line tool. With the tee muxer, the audio and video data will be encoded only once.
2310 With conventional multiple outputs, multiple encoding operations in parallel are initiated,
2311 which can be a very expensive process. The tee muxer is not useful when using the libavformat API
2312 directly because it is then possible to feed the same packets to several muxers directly.
2314 Since the tee muxer does not represent any particular output format, ffmpeg cannot auto-select
2315 output streams. So all streams intended for output must be specified using @code{-map}. See
2318 Some encoders may need different options depending on the output format;
2319 the auto-detection of this can not work with the tee muxer, so they need to be explicitly specified.
2320 The main example is the @option{global_header} flag.
2322 The slave outputs are specified in the file name given to the muxer,
2323 separated by '|'. If any of the slave name contains the '|' separator,
2324 leading or trailing spaces or any special character, those must be
2325 escaped (see @ref{quoting_and_escaping,,the "Quoting and escaping"
2326 section in the ffmpeg-utils(1) manual,ffmpeg-utils}).
2332 @item use_fifo @var{bool}
2333 If set to 1, slave outputs will be processed in separate threads using the @ref{fifo}
2334 muxer. This allows to compensate for different speed/latency/reliability of
2335 outputs and setup transparent recovery. By default this feature is turned off.
2338 Options to pass to fifo pseudo-muxer instances. See @ref{fifo}.
2342 Muxer options can be specified for each slave by prepending them as a list of
2343 @var{key}=@var{value} pairs separated by ':', between square brackets. If
2344 the options values contain a special character or the ':' separator, they
2345 must be escaped; note that this is a second level escaping.
2347 The following special options are also recognized:
2350 Specify the format name. Required if it cannot be guessed from the
2353 @item bsfs[/@var{spec}]
2354 Specify a list of bitstream filters to apply to the specified
2357 It is possible to specify to which streams a given bitstream filter
2358 applies, by appending a stream specifier to the option separated by
2359 @code{/}. @var{spec} must be a stream specifier (see @ref{Format
2360 stream specifiers}).
2362 If the stream specifier is not specified, the bitstream filters will be
2363 applied to all streams in the output. This will cause that output operation
2364 to fail if the output contains streams to which the bitstream filter cannot
2365 be applied e.g. @code{h264_mp4toannexb} being applied to an output containing an audio stream.
2367 Options for a bitstream filter must be specified in the form of @code{opt=value}.
2369 Several bitstream filters can be specified, separated by ",".
2371 @item use_fifo @var{bool}
2372 This allows to override tee muxer use_fifo option for individual slave muxer.
2375 This allows to override tee muxer fifo_options for individual slave muxer.
2379 Select the streams that should be mapped to the slave output,
2380 specified by a stream specifier. If not specified, this defaults to
2381 all the mapped streams. This will cause that output operation to fail
2382 if the output format does not accept all mapped streams.
2384 You may use multiple stream specifiers separated by commas (@code{,}) e.g.: @code{a:0,v}
2387 Specify behaviour on output failure. This can be set to either @code{abort} (which is
2388 default) or @code{ignore}. @code{abort} will cause whole process to fail in case of failure
2389 on this slave output. @code{ignore} will ignore failure on this output, so other outputs
2390 will continue without being affected.
2393 @subsection Examples
2397 Encode something and both archive it in a WebM file and stream it
2398 as MPEG-TS over UDP:
2400 ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
2401 "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
2405 As above, but continue streaming even if output to local file fails
2406 (for example local drive fills up):
2408 ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
2409 "[onfail=ignore]archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
2413 Use @command{ffmpeg} to encode the input, and send the output
2414 to three different destinations. The @code{dump_extra} bitstream
2415 filter is used to add extradata information to all the output video
2416 keyframes packets, as requested by the MPEG-TS format. The select
2417 option is applied to @file{out.aac} in order to make it contain only
2420 ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
2421 -f tee "[bsfs/v=dump_extra=freq=keyframe]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac"
2425 As above, but select only stream @code{a:1} for the audio output. Note
2426 that a second level escaping must be performed, as ":" is a special
2427 character used to separate options.
2429 ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
2430 -f tee "[bsfs/v=dump_extra=freq=keyframe]out.ts|[movflags=+faststart]out.mp4|[select=\'a:1\']out.aac"
2434 @section webm_dash_manifest
2436 WebM DASH Manifest muxer.
2438 This muxer implements the WebM DASH Manifest specification to generate the DASH
2439 manifest XML. It also supports manifest generation for DASH live streams.
2441 For more information see:
2445 WebM DASH Specification: @url{https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification}
2447 ISO DASH Specification: @url{http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip}
2452 This muxer supports the following options:
2455 @item adaptation_sets
2456 This option has the following syntax: "id=x,streams=a,b,c id=y,streams=d,e" where x and y are the
2457 unique identifiers of the adaptation sets and a,b,c,d and e are the indices of the corresponding
2458 audio and video streams. Any number of adaptation sets can be added using this option.
2461 Set this to 1 to create a live stream DASH Manifest. Default: 0.
2463 @item chunk_start_index
2464 Start index of the first chunk. This will go in the @samp{startNumber} attribute
2465 of the @samp{SegmentTemplate} element in the manifest. Default: 0.
2467 @item chunk_duration_ms
2468 Duration of each chunk in milliseconds. This will go in the @samp{duration}
2469 attribute of the @samp{SegmentTemplate} element in the manifest. Default: 1000.
2471 @item utc_timing_url
2472 URL of the page that will return the UTC timestamp in ISO format. This will go
2473 in the @samp{value} attribute of the @samp{UTCTiming} element in the manifest.
2476 @item time_shift_buffer_depth
2477 Smallest time (in seconds) shifting buffer for which any Representation is
2478 guaranteed to be available. This will go in the @samp{timeShiftBufferDepth}
2479 attribute of the @samp{MPD} element. Default: 60.
2481 @item minimum_update_period
2482 Minimum update period (in seconds) of the manifest. This will go in the
2483 @samp{minimumUpdatePeriod} attribute of the @samp{MPD} element. Default: 0.
2489 ffmpeg -f webm_dash_manifest -i video1.webm \
2490 -f webm_dash_manifest -i video2.webm \
2491 -f webm_dash_manifest -i audio1.webm \
2492 -f webm_dash_manifest -i audio2.webm \
2493 -map 0 -map 1 -map 2 -map 3 \
2495 -f webm_dash_manifest \
2496 -adaptation_sets "id=0,streams=0,1 id=1,streams=2,3" \
2502 WebM Live Chunk Muxer.
2504 This muxer writes out WebM headers and chunks as separate files which can be
2505 consumed by clients that support WebM Live streams via DASH.
2509 This muxer supports the following options:
2512 @item chunk_start_index
2513 Index of the first chunk (defaults to 0).
2516 Filename of the header where the initialization data will be written.
2518 @item audio_chunk_duration
2519 Duration of each audio chunk in milliseconds (defaults to 5000).
2524 ffmpeg -f v4l2 -i /dev/video0 \
2528 -s 640x360 -keyint_min 30 -g 30 \
2530 -header webm_live_video_360.hdr \
2531 -chunk_start_index 1 \
2532 webm_live_video_360_%d.chk \
2537 -header webm_live_audio_128.hdr \
2538 -chunk_start_index 1 \
2539 -audio_chunk_duration 1000 \
2540 webm_live_audio_128_%d.chk