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 master.m3u8.
271 One media playlist file is generated for each stream with filenames media_0.m3u8, media_1.m3u8, etc.
272 @item streaming @var{streaming}
273 Enable (1) or disable (0) chunk streaming mode of output. In chunk streaming
274 mode, each frame will be a moof fragment which forms a chunk.
275 @item adaptation_sets @var{adaptation_sets}
276 Assign streams to AdaptationSets. Syntax is "id=x,streams=a,b,c id=y,streams=d,e" with x and y being the IDs
277 of the adaptation sets and a,b,c,d and e are the indices of the mapped streams.
279 To map all video (or audio) streams to an AdaptationSet, "v" (or "a") can be used as stream identifier instead of IDs.
281 When no assignment is defined, this defaults to an AdaptationSet for each stream.
283 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,
284 descriptor is useful to the scheme defined by ISO/IEC 23009-1:2014/Amd.2:2015.
285 For example, -adaptation_sets "id=0,descriptor=<SupplementalProperty schemeIdUri=\"urn:mpeg:dash:srd:2014\" value=\"0,0,0,1,1,2,2\"/>,streams=v".
286 Please note that descriptor string should be a self-closing xml tag.
287 seg_duration, frag_duration and frag_type override the global option values for each adaptation set.
288 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"
289 type_id marks an adaptation set as containing streams meant to be used for Trick Mode for the referenced adaptation set.
290 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"
291 @item timeout @var{timeout}
292 Set timeout for socket I/O operations. Applicable only for HTTP output.
293 @item index_correction @var{index_correction}
294 Enable (1) or Disable (0) segment index correction logic. Applicable only when
295 @var{use_template} is enabled and @var{use_timeline} is disabled.
297 When enabled, the logic monitors the flow of segment indexes. If a streams's
298 segment index value is not at the expected real time position, then the logic
299 corrects that index value.
301 Typically this logic is needed in live streaming use cases. The network bandwidth
302 fluctuations are common during long run streaming. Each fluctuation can cause
303 the segment indexes fall behind the expected real time position.
304 @item format_options @var{options_list}
305 Set container format (mp4/webm) options using a @code{:} separated list of
306 key=value parameters. Values containing @code{:} special characters must be
309 @item global_sidx @var{global_sidx}
310 Write global SIDX atom. Applicable only for single file, mp4 output, non-streaming mode.
312 @item dash_segment_type @var{dash_segment_type}
316 If this flag is set, the dash segment files format will be selected based on the stream codec. This is the default mode.
319 If this flag is set, the dash segment files will be in in ISOBMFF format.
322 If this flag is set, the dash segment files will be in in WebM format.
325 @item ignore_io_errors @var{ignore_io_errors}
326 Ignore IO errors during open and write. Useful for long-duration runs with network output.
328 @item lhls @var{lhls}
329 Enable Low-latency HLS(LHLS). Adds #EXT-X-PREFETCH tag with current segment's URI.
330 Apple doesn't have an official spec for LHLS. Meanwhile hls.js player folks are
331 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
332 This option will also try to comply with the above open spec, till Apple's spec officially supports it.
333 Applicable only when @var{streaming} and @var{hls_playlist} options are enabled.
334 This is an experimental feature.
336 @item ldash @var{ldash}
337 Enable Low-latency Dash by constraining the presence and values of some elements.
339 @item master_m3u8_publish_rate @var{master_m3u8_publish_rate}
340 Publish master playlist repeatedly every after specified number of segment intervals.
342 @item -write_prft @var{write_prft}
343 Write Producer Reference Time elements on supported streams. This also enables writing
344 prft boxes in the underlying muxer. Applicable only when the @var{utc_url} option is enabled.
346 @item -mpd_profile @var{mpd_profile}
347 Set one or more manifest profiles.
349 @item -http_opts @var{http_opts}
350 A :-separated list of key=value options to pass to the underlying HTTP
351 protocol. Applicable only for HTTP output.
353 @item -target_latency @var{target_latency}
354 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.
355 This is an informative fields clients can use to measure the latency of the service.
362 Per-packet CRC (Cyclic Redundancy Check) testing format.
364 This muxer computes and prints the Adler-32 CRC for each audio
365 and video packet. By default audio frames are converted to signed
366 16-bit raw audio and video frames to raw video before computing the
369 The output of the muxer consists of a line for each audio and video
372 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, 0x@var{CRC}
375 @var{CRC} is a hexadecimal number 0-padded to 8 digits containing the
380 For example to compute the CRC of the audio and video frames in
381 @file{INPUT}, converted to raw audio and video packets, and store it
382 in the file @file{out.crc}:
384 ffmpeg -i INPUT -f framecrc out.crc
387 To print the information to stdout, use the command:
389 ffmpeg -i INPUT -f framecrc -
392 With @command{ffmpeg}, you can select the output format to which the
393 audio and video frames are encoded before computing the CRC for each
394 packet by specifying the audio and video codec. For example, to
395 compute the CRC of each decoded input audio frame converted to PCM
396 unsigned 8-bit and of each decoded input video frame converted to
397 MPEG-2 video, use the command:
399 ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -
402 See also the @ref{crc} muxer.
407 Per-packet hash testing format.
409 This muxer computes and prints a cryptographic hash for each audio
410 and video packet. This can be used for packet-by-packet equality
411 checks without having to individually do a binary comparison on each.
413 By default audio frames are converted to signed 16-bit raw audio and
414 video frames to raw video before computing the hash, but the output
415 of explicit conversions to other codecs can also be used. It uses the
416 SHA-256 cryptographic hash function by default, but supports several
419 The output of the muxer consists of a line for each audio and video
422 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, @var{hash}
425 @var{hash} is a hexadecimal number representing the computed hash
429 @item hash @var{algorithm}
430 Use the cryptographic hash function specified by the string @var{algorithm}.
431 Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
432 @code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
433 @code{SHA224}, @code{SHA256} (default), @code{SHA512/224}, @code{SHA512/256},
434 @code{SHA384}, @code{SHA512}, @code{CRC32} and @code{adler32}.
440 To compute the SHA-256 hash of the audio and video frames in @file{INPUT},
441 converted to raw audio and video packets, and store it in the file
444 ffmpeg -i INPUT -f framehash out.sha256
447 To print the information to stdout, using the MD5 hash function, use
450 ffmpeg -i INPUT -f framehash -hash md5 -
453 See also the @ref{hash} muxer.
458 Per-packet MD5 testing format.
460 This is a variant of the @ref{framehash} muxer. Unlike that muxer,
461 it defaults to using the MD5 hash function.
465 To compute the MD5 hash of the audio and video frames in @file{INPUT},
466 converted to raw audio and video packets, and store it in the file
469 ffmpeg -i INPUT -f framemd5 out.md5
472 To print the information to stdout, use the command:
474 ffmpeg -i INPUT -f framemd5 -
477 See also the @ref{framehash} and @ref{md5} muxers.
484 It accepts the following options:
488 Set the number of times to loop the output. Use @code{-1} for no loop, @code{0}
489 for looping indefinitely (default).
492 Force the delay (expressed in centiseconds) after the last frame. Each frame
493 ends with a delay until the next frame. The default is @code{-1}, which is a
494 special value to tell the muxer to re-use the previous delay. In case of a
495 loop, you might want to customize this value to mark a pause for instance.
498 For example, to encode a gif looping 10 times, with a 5 seconds delay between
501 ffmpeg -i INPUT -loop 10 -final_delay 500 out.gif
504 Note 1: if you wish to extract the frames into separate GIF files, you need to
505 force the @ref{image2} muxer:
507 ffmpeg -i INPUT -c:v gif -f image2 "out%d.gif"
510 Note 2: the GIF format has a very large time base: the delay between two frames
511 can therefore not be smaller than one centi second.
518 This muxer computes and prints a cryptographic hash of all the input
519 audio and video frames. This can be used for equality checks without
520 having to do a complete binary comparison.
522 By default audio frames are converted to signed 16-bit raw audio and
523 video frames to raw video before computing the hash, but the output
524 of explicit conversions to other codecs can also be used. Timestamps
525 are ignored. It uses the SHA-256 cryptographic hash function by default,
526 but supports several other algorithms.
528 The output of the muxer consists of a single line of the form:
529 @var{algo}=@var{hash}, where @var{algo} is a short string representing
530 the hash function used, and @var{hash} is a hexadecimal number
531 representing the computed hash.
534 @item hash @var{algorithm}
535 Use the cryptographic hash function specified by the string @var{algorithm}.
536 Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
537 @code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
538 @code{SHA224}, @code{SHA256} (default), @code{SHA512/224}, @code{SHA512/256},
539 @code{SHA384}, @code{SHA512}, @code{CRC32} and @code{adler32}.
545 To compute the SHA-256 hash of the input converted to raw audio and
546 video, and store it in the file @file{out.sha256}:
548 ffmpeg -i INPUT -f hash out.sha256
551 To print an MD5 hash to stdout use the command:
553 ffmpeg -i INPUT -f hash -hash md5 -
556 See also the @ref{framehash} muxer.
561 Apple HTTP Live Streaming muxer that segments MPEG-TS according to
562 the HTTP Live Streaming (HLS) specification.
564 It creates a playlist file, and one or more segment files. The output filename
565 specifies the playlist filename.
567 By default, the muxer creates a file for each segment produced. These files
568 have the same name as the playlist, followed by a sequential number and a
571 Make sure to require a closed GOP when encoding and to set the GOP
572 size to fit your segment time constraint.
574 For example, to convert an input file with @command{ffmpeg}:
576 ffmpeg -i in.mkv -c:v h264 -flags +cgop -g 30 -hls_time 1 out.m3u8
578 This example will produce the playlist, @file{out.m3u8}, and segment files:
579 @file{out0.ts}, @file{out1.ts}, @file{out2.ts}, etc.
581 See also the @ref{segment} muxer, which provides a more generic and
582 flexible implementation of a segmenter, and can be used to perform HLS
587 This muxer supports the following options:
590 @item hls_init_time @var{seconds}
591 Set the initial target segment length in seconds. Default value is @var{0}.
592 Segment will be cut on the next key frame after this time has passed on the first m3u8 list.
593 After the initial playlist is filled @command{ffmpeg} will cut segments
594 at duration equal to @code{hls_time}
596 @item hls_time @var{seconds}
597 Set the target segment length in seconds. Default value is 2.
598 Segment will be cut on the next key frame after this time has passed.
600 @item hls_list_size @var{size}
601 Set the maximum number of playlist entries. If set to 0 the list file
602 will contain all the segments. Default value is 5.
604 @item hls_delete_threshold @var{size}
605 Set the number of unreferenced segments to keep on disk before @code{hls_flags delete_segments}
606 deletes them. Increase this to allow continue clients to download segments which
607 were recently referenced in the playlist. Default value is 1, meaning segments older than
608 @code{hls_list_size+1} will be deleted.
610 @item hls_ts_options @var{options_list}
611 Set output format options using a :-separated list of key=value
612 parameters. Values containing @code{:} special characters must be
615 @item hls_wrap @var{wrap}
616 This is a deprecated option, you can use @code{hls_list_size}
617 and @code{hls_flags delete_segments} instead it
619 This option is useful to avoid to fill the disk with many segment
620 files, and limits the maximum number of segment files written to disk
624 @item hls_start_number_source
625 Start the playlist sequence number (@code{#EXT-X-MEDIA-SEQUENCE}) according to the specified source.
626 Unless @code{hls_flags single_file} is set, it also specifies source of starting sequence numbers of
627 segment and subtitle filenames. In any case, if @code{hls_flags append_list}
628 is set and read playlist sequence number is greater than the specified start sequence number,
629 then that value will be used as start value.
631 It accepts the following values:
635 @item generic (default)
636 Set the starting sequence numbers according to @var{start_number} option value.
639 The start number will be the seconds since epoch (1970-01-01 00:00:00)
642 The start number will be based on the current date/time as YYYYmmddHHMMSS. e.g. 20161231235759.
646 @item start_number @var{number}
647 Start the playlist sequence number (@code{#EXT-X-MEDIA-SEQUENCE}) from the specified @var{number}
648 when @var{hls_start_number_source} value is @var{generic}. (This is the default case.)
649 Unless @code{hls_flags single_file} is set, it also specifies starting sequence numbers of segment and subtitle filenames.
652 @item hls_allow_cache @var{allowcache}
653 Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments.
655 @item hls_base_url @var{baseurl}
656 Append @var{baseurl} to every entry in the playlist.
657 Useful to generate playlists with absolute paths.
659 Note that the playlist sequence number must be unique for each segment
660 and it is not to be confused with the segment filename sequence number
661 which can be cyclic, for example if the @option{wrap} option is
664 @item hls_segment_filename @var{filename}
665 Set the segment filename. Unless @code{hls_flags single_file} is set,
666 @var{filename} is used as a string format with the segment number:
668 ffmpeg -i in.nut -hls_segment_filename 'file%03d.ts' out.m3u8
670 This example will produce the playlist, @file{out.m3u8}, and segment files:
671 @file{file000.ts}, @file{file001.ts}, @file{file002.ts}, etc.
673 @var{filename} may contain full path or relative path specification,
674 but only the file name part without any path info will be contained in the m3u8 segment list.
675 Should a relative path be specified, the path of the created segment
676 files will be relative to the current working directory.
677 When strftime_mkdir is set, the whole expanded value of @var{filename} will be written into the m3u8 segment list.
679 When @code{var_stream_map} is set with two or more variant streams, the
680 @var{filename} pattern must contain the string "%v", this string specifies
681 the position of variant stream index in the generated segment file names.
683 ffmpeg -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
684 -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" \
685 -hls_segment_filename 'file_%v_%03d.ts' out_%v.m3u8
687 This example will produce the playlists segment file sets:
688 @file{file_0_000.ts}, @file{file_0_001.ts}, @file{file_0_002.ts}, etc. and
689 @file{file_1_000.ts}, @file{file_1_001.ts}, @file{file_1_002.ts}, etc.
691 The string "%v" may be present in the filename or in the last directory name
692 containing the file, but only in one of them. (Additionally, %v may appear multiple times in the last
693 sub-directory or filename.) If the string %v is present in the directory name, then
694 sub-directories are created after expanding the directory name pattern. This
695 enables creation of segments corresponding to different variant streams in
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 'vs%v/file_%03d.ts' vs%v/out.m3u8
702 This example will produce the playlists segment file sets:
703 @file{vs0/file_000.ts}, @file{vs0/file_001.ts}, @file{vs0/file_002.ts}, etc. and
704 @file{vs1/file_000.ts}, @file{vs1/file_001.ts}, @file{vs1/file_002.ts}, etc.
707 Same as strftime option, will be deprecated.
710 Use strftime() on @var{filename} to expand the segment filename with localtime.
711 The segment number is also available in this mode, but to use it, you need to specify second_level_segment_index
712 hls_flag and %%d will be the specifier.
714 ffmpeg -i in.nut -strftime 1 -hls_segment_filename 'file-%Y%m%d-%s.ts' out.m3u8
716 This example will produce the playlist, @file{out.m3u8}, and segment files:
717 @file{file-20160215-1455569023.ts}, @file{file-20160215-1455569024.ts}, etc.
718 Note: On some systems/environments, the @code{%s} specifier is not available. See
719 @code{strftime()} documentation.
721 ffmpeg -i in.nut -strftime 1 -hls_flags second_level_segment_index -hls_segment_filename 'file-%Y%m%d-%%04d.ts' out.m3u8
723 This example will produce the playlist, @file{out.m3u8}, and segment files:
724 @file{file-20160215-0001.ts}, @file{file-20160215-0002.ts}, etc.
726 @item use_localtime_mkdir
727 Same as strftime_mkdir option, will be deprecated .
730 Used together with -strftime_mkdir, it will create all subdirectories which
731 is expanded in @var{filename}.
733 ffmpeg -i in.nut -strftime 1 -strftime_mkdir 1 -hls_segment_filename '%Y%m%d/file-%Y%m%d-%s.ts' out.m3u8
735 This example will create a directory 201560215 (if it does not exist), and then
736 produce the playlist, @file{out.m3u8}, and segment files:
737 @file{20160215/file-20160215-1455569023.ts}, @file{20160215/file-20160215-1455569024.ts}, etc.
740 ffmpeg -i in.nut -strftime 1 -strftime_mkdir 1 -hls_segment_filename '%Y/%m/%d/file-%Y%m%d-%s.ts' out.m3u8
742 This example will create a directory hierarchy 2016/02/15 (if any of them do not exist), and then
743 produce the playlist, @file{out.m3u8}, and segment files:
744 @file{2016/02/15/file-20160215-1455569023.ts}, @file{2016/02/15/file-20160215-1455569024.ts}, etc.
747 @item hls_key_info_file @var{key_info_file}
748 Use the information in @var{key_info_file} for segment encryption. The first
749 line of @var{key_info_file} specifies the key URI written to the playlist. The
750 key URL is used to access the encryption key during playback. The second line
751 specifies the path to the key file used to obtain the key during the encryption
752 process. The key file is read as a single packed array of 16 octets in binary
753 format. The optional third line specifies the initialization vector (IV) as a
754 hexadecimal string to be used instead of the segment sequence number (default)
755 for encryption. Changes to @var{key_info_file} will result in segment
756 encryption with the new key/IV and an entry in the playlist for the new key
757 URI/IV if @code{hls_flags periodic_rekey} is enabled.
759 Key info file format:
768 http://server/file.key
773 Example key file paths:
781 0123456789ABCDEF0123456789ABCDEF
784 Key info file example:
786 http://server/file.key
788 0123456789ABCDEF0123456789ABCDEF
791 Example shell script:
795 openssl rand 16 > file.key
796 echo $BASE_URL/file.key > file.keyinfo
797 echo file.key >> file.keyinfo
798 echo $(openssl rand -hex 16) >> file.keyinfo
799 ffmpeg -f lavfi -re -i testsrc -c:v h264 -hls_flags delete_segments \
800 -hls_key_info_file file.keyinfo out.m3u8
803 @item -hls_enc @var{enc}
804 Enable (1) or disable (0) the AES128 encryption.
805 When enabled every segment generated is encrypted and the encryption key
806 is saved as @var{playlist name}.key.
808 @item -hls_enc_key @var{key}
809 Hex-coded 16byte key to encrypt the segments, by default it
810 is randomly generated.
812 @item -hls_enc_key_url @var{keyurl}
813 If set, @var{keyurl} is prepended instead of @var{baseurl} to the key filename
816 @item -hls_enc_iv @var{iv}
817 Hex-coded 16byte initialization vector for every segment instead
818 of the autogenerated ones.
820 @item hls_segment_type @var{flags}
825 Output segment files in MPEG-2 Transport Stream format. This is
826 compatible with all HLS versions.
829 Output segment files in fragmented MP4 format, similar to MPEG-DASH.
830 fmp4 files may be used in HLS version 7 and above.
834 @item hls_fmp4_init_filename @var{filename}
835 Set filename to the fragment files header file, default filename is @file{init.mp4}.
837 When @code{var_stream_map} is set with two or more variant streams, the
838 @var{filename} pattern must contain the string "%v", this string specifies
839 the position of variant stream index in the generated init file names.
840 The string "%v" may be present in the filename or in the last directory name
841 containing the file. If the string is present in the directory name, then
842 sub-directories are created after expanding the directory name pattern. This
843 enables creation of init files corresponding to different variant streams in
846 @item hls_flags @var{flags}
851 If this flag is set, the muxer will store all segments in a single MPEG-TS
852 file, and will use byte ranges in the playlist. HLS playlists generated with
853 this way will have the version number 4.
856 ffmpeg -i in.nut -hls_flags single_file out.m3u8
858 Will produce the playlist, @file{out.m3u8}, and a single segment file,
861 @item delete_segments
862 Segment files removed from the playlist are deleted after a period of time
863 equal to the duration of the segment plus the duration of the playlist.
866 Append new segments into the end of old segment list,
867 and remove the @code{#EXT-X-ENDLIST} from the old segment list.
869 @item round_durations
870 Round the duration info in the playlist file segment info to integer
871 values, instead of using floating point.
874 Add the @code{#EXT-X-DISCONTINUITY} tag to the playlist, before the
875 first segment's information.
878 Do not append the @code{EXT-X-ENDLIST} tag at the end of the playlist.
881 The file specified by @code{hls_key_info_file} will be checked periodically and
882 detect updates to the encryption info. Be sure to replace this file atomically,
883 including the file containing the AES encryption key.
885 @item independent_segments
886 Add the @code{#EXT-X-INDEPENDENT-SEGMENTS} to playlists that has video segments
887 and when all the segments of that playlist are guaranteed to start with a Key frame.
890 Add the @code{#EXT-X-I-FRAMES-ONLY} to playlists that has video segments
891 and can play only I-frames in the @code{#EXT-X-BYTERANGE} mode.
894 Allow segments to start on frames other than keyframes. This improves
895 behavior on some players when the time between keyframes is inconsistent,
896 but may make things worse on others, and can cause some oddities during
897 seeking. This flag should be used with the @code{hls_time} option.
899 @item program_date_time
900 Generate @code{EXT-X-PROGRAM-DATE-TIME} tags.
902 @item second_level_segment_index
903 Makes it possible to use segment indexes as %%d in hls_segment_filename expression
904 besides date/time values when strftime is on.
905 To get fixed width numbers with trailing zeroes, %%0xd format is available where x is the required width.
907 @item second_level_segment_size
908 Makes it possible to use segment sizes (counted in bytes) as %%s in hls_segment_filename
909 expression besides date/time values when strftime is on.
910 To get fixed width numbers with trailing zeroes, %%0xs format is available where x is the required width.
912 @item second_level_segment_duration
913 Makes it possible to use segment duration (calculated in microseconds) as %%t in hls_segment_filename
914 expression besides date/time values when strftime is on.
915 To get fixed width numbers with trailing zeroes, %%0xt format is available where x is the required width.
918 ffmpeg -i sample.mpeg \
919 -f hls -hls_time 3 -hls_list_size 5 \
920 -hls_flags second_level_segment_index+second_level_segment_size+second_level_segment_duration \
921 -strftime 1 -strftime_mkdir 1 -hls_segment_filename "segment_%Y%m%d%H%M%S_%%04d_%%08s_%%013t.ts" stream.m3u8
923 This will produce segments like this:
924 @file{segment_20170102194334_0003_00122200_0000003000000.ts}, @file{segment_20170102194334_0004_00120072_0000003000000.ts} etc.
927 Write segment data to filename.tmp and rename to filename only once the segment is complete. A webserver
928 serving up segments can be configured to reject requests to *.tmp to prevent access to in-progress segments
929 before they have been added to the m3u8 playlist. This flag also affects how m3u8 playlist files are created.
930 If this flag is set, all playlist files will written into temporary file and renamed after they are complete, similarly as segments are handled.
931 But playlists with @code{file} protocol and with type (@code{hls_playlist_type}) other than @code{vod}
932 are always written into temporary file regardless of this flag. Master playlist files (@code{master_pl_name}), if any, with @code{file} protocol,
933 are always written into temporary file regardless of this flag if @code{master_pl_publish_rate} value is other than zero.
937 @item hls_playlist_type event
938 Emit @code{#EXT-X-PLAYLIST-TYPE:EVENT} in the m3u8 header. Forces
939 @option{hls_list_size} to 0; the playlist can only be appended to.
941 @item hls_playlist_type vod
942 Emit @code{#EXT-X-PLAYLIST-TYPE:VOD} in the m3u8 header. Forces
943 @option{hls_list_size} to 0; the playlist must not change.
946 Use the given HTTP method to create the hls files.
948 ffmpeg -re -i in.ts -f hls -method PUT http://example.com/live/out.m3u8
950 This example will upload all the mpegts segment files to the HTTP
951 server using the HTTP PUT method, and update the m3u8 files every
952 @code{refresh} times using the same method.
953 Note that the HTTP server must support the given method for uploading
956 @item http_user_agent
957 Override User-Agent field in HTTP header. Applicable only for HTTP output.
960 Map string which specifies how to group the audio, video and subtitle streams
961 into different variant streams. The variant stream groups are separated
963 Expected string format is like this "a:0,v:0 a:1,v:1 ....". Here a:, v:, s: are
964 the keys to specify audio, video and subtitle streams respectively.
965 Allowed values are 0 to 9 (limited just based on practical usage).
967 When there are two or more variant streams, the output filename pattern must
968 contain the string "%v", this string specifies the position of variant stream
969 index in the output media playlist filenames. The string "%v" may be present in
970 the filename or in the last directory name containing the file. If the string is
971 present in the directory name, then sub-directories are created after expanding
972 the directory name pattern. This enables creation of variant streams in
976 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
977 -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" \
978 http://example.com/live/out_%v.m3u8
980 This example creates two hls variant streams. The first variant stream will
981 contain video stream of bitrate 1000k and audio stream of bitrate 64k and the
982 second variant stream will contain video stream of bitrate 256k and audio
983 stream of bitrate 32k. Here, two media playlist with file names out_0.m3u8 and
984 out_1.m3u8 will be created. If you want something meaningful text instead of indexes
985 in result names, you may specify names for each or some of the variants
986 as in the following example.
990 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
991 -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" \
992 http://example.com/live/out_%v.m3u8
995 This example creates two hls variant streams as in the previous one.
996 But here, the two media playlist with file names out_my_hd.m3u8 and
997 out_my_sd.m3u8 will be created.
1000 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k \
1001 -map 0:v -map 0:a -map 0:v -f hls -var_stream_map "v:0 a:0 v:1" \
1002 http://example.com/live/out_%v.m3u8
1004 This example creates three hls variant streams. The first variant stream will
1005 be a video only stream with video bitrate 1000k, the second variant stream will
1006 be an audio only stream with bitrate 64k and the third variant stream will be a
1007 video only stream with bitrate 256k. Here, three media playlist with file names
1008 out_0.m3u8, out_1.m3u8 and out_2.m3u8 will be created.
1010 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
1011 -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" \
1012 http://example.com/live/vs_%v/out.m3u8
1014 This example creates the variant streams in subdirectories. Here, the first
1015 media playlist is created at @file{http://example.com/live/vs_0/out.m3u8} and
1016 the second one at @file{http://example.com/live/vs_1/out.m3u8}.
1018 ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k -b:v:1 3000k \
1019 -map 0:a -map 0:a -map 0:v -map 0:v -f hls \
1020 -var_stream_map "a:0,agroup:aud_low a:1,agroup:aud_high v:0,agroup:aud_low v:1,agroup:aud_high" \
1021 -master_pl_name master.m3u8 \
1022 http://example.com/live/out_%v.m3u8
1024 This example creates two audio only and two video only variant streams. In
1025 addition to the #EXT-X-STREAM-INF tag for each variant stream in the master
1026 playlist, #EXT-X-MEDIA tag is also added for the two audio only variant streams
1027 and they are mapped to the two video only variant streams with audio group names
1028 'aud_low' and 'aud_high'.
1030 By default, a single hls variant containing all the encoded streams is created.
1033 ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k \
1034 -map 0:a -map 0:a -map 0:v -f hls \
1035 -var_stream_map "a:0,agroup:aud_low,default:yes a:1,agroup:aud_low v:0,agroup:aud_low" \
1036 -master_pl_name master.m3u8 \
1037 http://example.com/live/out_%v.m3u8
1039 This example creates two audio only and one video only variant streams. In
1040 addition to the #EXT-X-STREAM-INF tag for each variant stream in the master
1041 playlist, #EXT-X-MEDIA tag is also added for the two audio only variant streams
1042 and they are mapped to the one video only variant streams with audio group name
1043 'aud_low', and the audio group have default stat is NO or YES.
1045 By default, a single hls variant containing all the encoded streams is created.
1048 ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k \
1049 -map 0:a -map 0:a -map 0:v -f hls \
1050 -var_stream_map "a:0,agroup:aud_low,default:yes,language:ENG a:1,agroup:aud_low,language:CHN v:0,agroup:aud_low" \
1051 -master_pl_name master.m3u8 \
1052 http://example.com/live/out_%v.m3u8
1054 This example creates two audio only and one video only variant streams. In
1055 addition to the #EXT-X-STREAM-INF tag for each variant stream in the master
1056 playlist, #EXT-X-MEDIA tag is also added for the two audio only variant streams
1057 and they are mapped to the one video only variant streams with audio group name
1058 'aud_low', and the audio group have default stat is NO or YES, and one audio
1059 have and language is named ENG, the other audio language is named CHN.
1061 By default, a single hls variant containing all the encoded streams is created.
1064 Map string which specifies different closed captions groups and their
1065 attributes. The closed captions stream groups are separated by space.
1066 Expected string format is like this
1067 "ccgroup:<group name>,instreamid:<INSTREAM-ID>,language:<language code> ....".
1068 'ccgroup' and 'instreamid' are mandatory attributes. 'language' is an optional
1070 The closed captions groups configured using this option are mapped to different
1071 variant streams by providing the same 'ccgroup' name in the
1072 @code{var_stream_map} string. If @code{var_stream_map} is not set, then the
1073 first available ccgroup in @code{cc_stream_map} is mapped to the output variant
1074 stream. The examples for these two use cases are given below.
1077 ffmpeg -re -i in.ts -b:v 1000k -b:a 64k -a53cc 1 -f hls \
1078 -cc_stream_map "ccgroup:cc,instreamid:CC1,language:en" \
1079 -master_pl_name master.m3u8 \
1080 http://example.com/live/out.m3u8
1082 This example adds @code{#EXT-X-MEDIA} tag with @code{TYPE=CLOSED-CAPTIONS} in
1083 the master playlist with group name 'cc', language 'en' (english) and
1084 INSTREAM-ID 'CC1'. Also, it adds @code{CLOSED-CAPTIONS} attribute with group
1085 name 'cc' for the output variant stream.
1087 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
1088 -a53cc:0 1 -a53cc:1 1\
1089 -map 0:v -map 0:a -map 0:v -map 0:a -f hls \
1090 -cc_stream_map "ccgroup:cc,instreamid:CC1,language:en ccgroup:cc,instreamid:CC2,language:sp" \
1091 -var_stream_map "v:0,a:0,ccgroup:cc v:1,a:1,ccgroup:cc" \
1092 -master_pl_name master.m3u8 \
1093 http://example.com/live/out_%v.m3u8
1095 This example adds two @code{#EXT-X-MEDIA} tags with @code{TYPE=CLOSED-CAPTIONS} in
1096 the master playlist for the INSTREAM-IDs 'CC1' and 'CC2'. Also, it adds
1097 @code{CLOSED-CAPTIONS} attribute with group name 'cc' for the two output variant
1100 @item master_pl_name
1101 Create HLS master playlist with the given name.
1104 ffmpeg -re -i in.ts -f hls -master_pl_name master.m3u8 http://example.com/live/out.m3u8
1106 This example creates HLS master playlist with name master.m3u8 and it is
1107 published at http://example.com/live/
1109 @item master_pl_publish_rate
1110 Publish master play list repeatedly every after specified number of segment intervals.
1113 ffmpeg -re -i in.ts -f hls -master_pl_name master.m3u8 \
1114 -hls_time 2 -master_pl_publish_rate 30 http://example.com/live/out.m3u8
1117 This example creates HLS master playlist with name master.m3u8 and keep
1118 publishing it repeatedly every after 30 segments i.e. every after 60s.
1120 @item http_persistent
1121 Use persistent HTTP connections. Applicable only for HTTP output.
1124 Set timeout for socket I/O operations. Applicable only for HTTP output.
1126 @item -ignore_io_errors
1127 Ignore IO errors during open, write and delete. Useful for long-duration runs with network output.
1130 Set custom HTTP headers, can override built in default headers. Applicable only for HTTP output.
1139 Microsoft's icon file format (ICO) has some strict limitations that should be noted:
1143 Size cannot exceed 256 pixels in any dimension
1146 Only BMP and PNG images can be stored
1149 If a BMP image is used, it must be one of the following pixel formats:
1151 BMP Bit Depth FFmpeg Pixel Format
1161 If a BMP image is used, it must use the BITMAPINFOHEADER DIB header
1164 If a PNG image is used, it must use the rgba pixel format
1172 The image file muxer writes video frames to image files.
1174 The output filenames are specified by a pattern, which can be used to
1175 produce sequentially numbered series of files.
1176 The pattern may contain the string "%d" or "%0@var{N}d", this string
1177 specifies the position of the characters representing a numbering in
1178 the filenames. If the form "%0@var{N}d" is used, the string
1179 representing the number in each filename is 0-padded to @var{N}
1180 digits. The literal character '%' can be specified in the pattern with
1183 If the pattern contains "%d" or "%0@var{N}d", the first filename of
1184 the file list specified will contain the number 1, all the following
1185 numbers will be sequential.
1187 The pattern may contain a suffix which is used to automatically
1188 determine the format of the image files to write.
1190 For example the pattern "img-%03d.bmp" will specify a sequence of
1191 filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ...,
1192 @file{img-010.bmp}, etc.
1193 The pattern "img%%-%d.jpg" will specify a sequence of filenames of the
1194 form @file{img%-1.jpg}, @file{img%-2.jpg}, ..., @file{img%-10.jpg},
1197 The image muxer supports the .Y.U.V image file format. This format is
1198 special in that that each image frame consists of three files, for
1199 each of the YUV420P components. To read or write this image file format,
1200 specify the name of the '.Y' file. The muxer will automatically open the
1201 '.U' and '.V' files as required.
1207 If set to 1, expand the filename with pts from pkt->pts.
1211 Start the sequence from the specified number. Default value is 1.
1214 If set to 1, the filename will always be interpreted as just a
1215 filename, not a pattern, and the corresponding file will be continuously
1216 overwritten with new images. Default value is 0.
1219 If set to 1, expand the filename with date and time information from
1220 @code{strftime()}. Default value is 0.
1222 @item protocol_opts @var{options_list}
1223 Set protocol options as a :-separated list of key=value parameters. Values
1224 containing the @code{:} special character must be escaped.
1228 @subsection Examples
1230 The following example shows how to use @command{ffmpeg} for creating a
1231 sequence of files @file{img-001.jpeg}, @file{img-002.jpeg}, ...,
1232 taking one image every second from the input video:
1234 ffmpeg -i in.avi -vsync cfr -r 1 -f image2 'img-%03d.jpeg'
1237 Note that with @command{ffmpeg}, if the format is not specified with the
1238 @code{-f} option and the output filename specifies an image file
1239 format, the image2 muxer is automatically selected, so the previous
1240 command can be written as:
1242 ffmpeg -i in.avi -vsync cfr -r 1 'img-%03d.jpeg'
1245 Note also that the pattern must not necessarily contain "%d" or
1246 "%0@var{N}d", for example to create a single image file
1247 @file{img.jpeg} from the start of the input video you can employ the command:
1249 ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg
1252 The @option{strftime} option allows you to expand the filename with
1253 date and time information. Check the documentation of
1254 the @code{strftime()} function for the syntax.
1256 For example to generate image files from the @code{strftime()}
1257 "%Y-%m-%d_%H-%M-%S" pattern, the following @command{ffmpeg} command
1260 ffmpeg -f v4l2 -r 1 -i /dev/video0 -f image2 -strftime 1 "%Y-%m-%d_%H-%M-%S.jpg"
1263 You can set the file name with current frame's PTS:
1265 ffmpeg -f v4l2 -r 1 -i /dev/video0 -copyts -f image2 -frame_pts true %d.jpg"
1268 A more complex example is to publish contents of your desktop directly to a
1269 WebDAV server every second:
1271 ffmpeg -f x11grab -framerate 1 -i :0.0 -q:v 6 -update 1 -protocol_opts method=PUT http://example.com/desktop.jpg
1276 Matroska container muxer.
1278 This muxer implements the matroska and webm container specs.
1280 @subsection Metadata
1282 The recognized metadata settings in this muxer are:
1286 Set title name provided to a single track.
1289 Specify the language of the track in the Matroska languages form.
1291 The language can be either the 3 letters bibliographic ISO-639-2 (ISO
1292 639-2/B) form (like "fre" for French), or a language code mixed with a
1293 country code for specialities in languages (like "fre-ca" for Canadian
1297 Set stereo 3D video layout of two views in a single video track.
1299 The following values are recognized:
1304 Both views are arranged side by side, Left-eye view is on the left
1306 Both views are arranged in top-bottom orientation, Left-eye view is at bottom
1308 Both views are arranged in top-bottom orientation, Left-eye view is on top
1309 @item checkerboard_rl
1310 Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first
1311 @item checkerboard_lr
1312 Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first
1313 @item row_interleaved_rl
1314 Each view is constituted by a row based interleaving, Right-eye view is first row
1315 @item row_interleaved_lr
1316 Each view is constituted by a row based interleaving, Left-eye view is first row
1317 @item col_interleaved_rl
1318 Both views are arranged in a column based interleaving manner, Right-eye view is first column
1319 @item col_interleaved_lr
1320 Both views are arranged in a column based interleaving manner, Left-eye view is first column
1321 @item anaglyph_cyan_red
1322 All frames are in anaglyph format viewable through red-cyan filters
1324 Both views are arranged side by side, Right-eye view is on the left
1325 @item anaglyph_green_magenta
1326 All frames are in anaglyph format viewable through green-magenta filters
1328 Both eyes laced in one Block, Left-eye view is first
1330 Both eyes laced in one Block, Right-eye view is first
1334 For example a 3D WebM clip can be created using the following command line:
1336 ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm
1341 This muxer supports the following options:
1344 @item reserve_index_space
1345 By default, this muxer writes the index for seeking (called cues in Matroska
1346 terms) at the end of the file, because it cannot know in advance how much space
1347 to leave for the index at the beginning of the file. However for some use cases
1348 -- e.g. streaming where seeking is possible but slow -- it is useful to put the
1349 index at the beginning of the file.
1351 If this option is set to a non-zero value, the muxer will reserve a given amount
1352 of space in the file header and then try to write the cues there when the muxing
1353 finishes. If the available space does not suffice, muxing will fail. A safe size
1354 for most use cases should be about 50kB per hour of video.
1356 Note that cues are only written if the output is seekable and this option will
1357 have no effect if it is not.
1365 This is a variant of the @ref{hash} muxer. Unlike that muxer, it
1366 defaults to using the MD5 hash function.
1368 @subsection Examples
1370 To compute the MD5 hash of the input converted to raw
1371 audio and video, and store it in the file @file{out.md5}:
1373 ffmpeg -i INPUT -f md5 out.md5
1376 You can print the MD5 to stdout with the command:
1378 ffmpeg -i INPUT -f md5 -
1381 See also the @ref{hash} and @ref{framemd5} muxers.
1383 @section mov, mp4, ismv
1385 MOV/MP4/ISMV (Smooth Streaming) muxer.
1387 The mov/mp4/ismv muxer supports fragmentation. Normally, a MOV/MP4
1388 file has all the metadata about all packets stored in one location
1389 (written at the end of the file, it can be moved to the start for
1390 better playback by adding @var{faststart} to the @var{movflags}, or
1391 using the @command{qt-faststart} tool). A fragmented
1392 file consists of a number of fragments, where packets and metadata
1393 about these packets are stored together. Writing a fragmented
1394 file has the advantage that the file is decodable even if the
1395 writing is interrupted (while a normal MOV/MP4 is undecodable if
1396 it is not properly finished), and it requires less memory when writing
1397 very long files (since writing normal MOV/MP4 files stores info about
1398 every single packet in memory until the file is closed). The downside
1399 is that it is less compatible with other applications.
1403 Fragmentation is enabled by setting one of the AVOptions that define
1404 how to cut the file into fragments:
1407 @item -moov_size @var{bytes}
1408 Reserves space for the moov atom at the beginning of the file instead of placing the
1409 moov atom at the end. If the space reserved is insufficient, muxing will fail.
1410 @item -movflags frag_keyframe
1411 Start a new fragment at each video keyframe.
1412 @item -frag_duration @var{duration}
1413 Create fragments that are @var{duration} microseconds long.
1414 @item -frag_size @var{size}
1415 Create fragments that contain up to @var{size} bytes of payload data.
1416 @item -movflags frag_custom
1417 Allow the caller to manually choose when to cut fragments, by
1418 calling @code{av_write_frame(ctx, NULL)} to write a fragment with
1419 the packets written so far. (This is only useful with other
1420 applications integrating libavformat, not from @command{ffmpeg}.)
1421 @item -min_frag_duration @var{duration}
1422 Don't create fragments that are shorter than @var{duration} microseconds long.
1425 If more than one condition is specified, fragments are cut when
1426 one of the specified conditions is fulfilled. The exception to this is
1427 @code{-min_frag_duration}, which has to be fulfilled for any of the other
1428 conditions to apply.
1430 Additionally, the way the output file is written can be adjusted
1431 through a few other options:
1434 @item -movflags empty_moov
1435 Write an initial moov atom directly at the start of the file, without
1436 describing any samples in it. Generally, an mdat/moov pair is written
1437 at the start of the file, as a normal MOV/MP4 file, containing only
1438 a short portion of the file. With this option set, there is no initial
1439 mdat atom, and the moov atom only describes the tracks but has
1442 This option is implicitly set when writing ismv (Smooth Streaming) files.
1443 @item -movflags separate_moof
1444 Write a separate moof (movie fragment) atom for each track. Normally,
1445 packets for all tracks are written in a moof atom (which is slightly
1446 more efficient), but with this option set, the muxer writes one moof/mdat
1447 pair for each track, making it easier to separate tracks.
1449 This option is implicitly set when writing ismv (Smooth Streaming) files.
1450 @item -movflags skip_sidx
1451 Skip writing of sidx atom. When bitrate overhead due to sidx atom is high,
1452 this option could be used for cases where sidx atom is not mandatory.
1453 When global_sidx flag is enabled, this option will be ignored.
1454 @item -movflags faststart
1455 Run a second pass moving the index (moov atom) to the beginning of the file.
1456 This operation can take a while, and will not work in various situations such
1457 as fragmented output, thus it is not enabled by default.
1458 @item -movflags rtphint
1459 Add RTP hinting tracks to the output file.
1460 @item -movflags disable_chpl
1461 Disable Nero chapter markers (chpl atom). Normally, both Nero chapters
1462 and a QuickTime chapter track are written to the file. With this option
1463 set, only the QuickTime chapter track will be written. Nero chapters can
1464 cause failures when the file is reprocessed with certain tagging programs, like
1465 mp3Tag 2.61a and iTunes 11.3, most likely other versions are affected as well.
1466 @item -movflags omit_tfhd_offset
1467 Do not write any absolute base_data_offset in tfhd atoms. This avoids
1468 tying fragments to absolute byte positions in the file/streams.
1469 @item -movflags default_base_moof
1470 Similarly to the omit_tfhd_offset, this flag avoids writing the
1471 absolute base_data_offset field in tfhd atoms, but does so by using
1472 the new default-base-is-moof flag instead. This flag is new from
1473 14496-12:2012. This may make the fragments easier to parse in certain
1474 circumstances (avoiding basing track fragment location calculations
1475 on the implicit end of the previous track fragment).
1477 Specify @code{on} to force writing a timecode track, @code{off} to disable it
1478 and @code{auto} to write a timecode track only for mov and mp4 output (default).
1479 @item -movflags negative_cts_offsets
1480 Enables utilization of version 1 of the CTTS box, in which the CTS offsets can
1481 be negative. This enables the initial sample to have DTS/CTS of zero, and
1482 reduces the need for edit lists for some cases such as video tracks with
1483 B-frames. Additionally, eases conformance with the DASH-IF interoperability
1486 This option is implicitly set when writing ismv (Smooth Streaming) files.
1488 Write producer time reference box (PRFT) with a specified time source for the
1489 NTP field in the PRFT box. Set value as @samp{wallclock} to specify timesource
1490 as wallclock time and @samp{pts} to specify timesource as input packets' PTS
1493 Setting value to @samp{pts} is applicable only for a live encoding use case,
1494 where PTS values are set as as wallclock time at the source. For example, an
1495 encoding use case with decklink capture source where @option{video_pts} and
1496 @option{audio_pts} are set to @samp{abs_wallclock}.
1501 Smooth Streaming content can be pushed in real time to a publishing
1502 point on IIS with this muxer. Example:
1504 ffmpeg -re @var{<normal input/transcoding options>} -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1)
1507 @subsection Audible AAX
1509 Audible AAX files are encrypted M4B files, and they can be decrypted by specifying a 4 byte activation secret.
1511 ffmpeg -activation_bytes 1CEB00DA -i test.aax -vn -c:a copy output.mp4
1516 The MP3 muxer writes a raw MP3 stream with the following optional features:
1519 An ID3v2 metadata header at the beginning (enabled by default). Versions 2.3 and
1520 2.4 are supported, the @code{id3v2_version} private option controls which one is
1521 used (3 or 4). Setting @code{id3v2_version} to 0 disables the ID3v2 header
1524 The muxer supports writing attached pictures (APIC frames) to the ID3v2 header.
1525 The pictures are supplied to the muxer in form of a video stream with a single
1526 packet. There can be any number of those streams, each will correspond to a
1527 single APIC frame. The stream metadata tags @var{title} and @var{comment} map
1528 to APIC @var{description} and @var{picture type} respectively. See
1529 @url{http://id3.org/id3v2.4.0-frames} for allowed picture types.
1531 Note that the APIC frames must be written at the beginning, so the muxer will
1532 buffer the audio frames until it gets all the pictures. It is therefore advised
1533 to provide the pictures as soon as possible to avoid excessive buffering.
1536 A Xing/LAME frame right after the ID3v2 header (if present). It is enabled by
1537 default, but will be written only if the output is seekable. The
1538 @code{write_xing} private option can be used to disable it. The frame contains
1539 various information that may be useful to the decoder, like the audio duration
1543 A legacy ID3v1 tag at the end of the file (disabled by default). It may be
1544 enabled with the @code{write_id3v1} private option, but as its capabilities are
1545 very limited, its usage is not recommended.
1550 Write an mp3 with an ID3v2.3 header and an ID3v1 footer:
1552 ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3
1555 To attach a picture to an mp3 file select both the audio and the picture stream
1558 ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1
1559 -metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3
1562 Write a "clean" MP3 without any extra features:
1564 ffmpeg -i input.wav -write_xing 0 -id3v2_version 0 out.mp3
1569 MPEG transport stream muxer.
1571 This muxer implements ISO 13818-1 and part of ETSI EN 300 468.
1573 The recognized metadata settings in mpegts muxer are @code{service_provider}
1574 and @code{service_name}. If they are not set the default for
1575 @code{service_provider} is @samp{FFmpeg} and the default for
1576 @code{service_name} is @samp{Service01}.
1580 The muxer options are:
1583 @item mpegts_transport_stream_id @var{integer}
1584 Set the @samp{transport_stream_id}. This identifies a transponder in DVB.
1585 Default is @code{0x0001}.
1587 @item mpegts_original_network_id @var{integer}
1588 Set the @samp{original_network_id}. This is unique identifier of a
1589 network in DVB. Its main use is in the unique identification of a service
1590 through the path @samp{Original_Network_ID, Transport_Stream_ID}. Default
1593 @item mpegts_service_id @var{integer}
1594 Set the @samp{service_id}, also known as program in DVB. Default is
1597 @item mpegts_service_type @var{integer}
1598 Set the program @samp{service_type}. Default is @code{digital_tv}.
1599 Accepts the following options:
1602 Any hexadecimal value between @code{0x01} and @code{0xff} as defined in
1607 Digital Radio service.
1610 @item advanced_codec_digital_radio
1611 Advanced Codec Digital Radio service.
1612 @item mpeg2_digital_hdtv
1613 MPEG2 Digital HDTV service.
1614 @item advanced_codec_digital_sdtv
1615 Advanced Codec Digital SDTV service.
1616 @item advanced_codec_digital_hdtv
1617 Advanced Codec Digital HDTV service.
1620 @item mpegts_pmt_start_pid @var{integer}
1621 Set the first PID for PMTs. Default is @code{0x1000}, minimum is @code{0x0020},
1622 maximum is @code{0x1ffa}.
1624 @item mpegts_start_pid @var{integer}
1625 Set the first PID for elementary streams. Default is @code{0x0100}, minimum is
1626 @code{0x0020}, maximum is @code{0x1ffa}.
1628 @item mpegts_m2ts_mode @var{boolean}
1629 Enable m2ts mode if set to @code{1}. Default value is @code{-1} which
1632 @item muxrate @var{integer}
1633 Set a constant muxrate. Default is VBR.
1635 @item pes_payload_size @var{integer}
1636 Set minimum PES packet payload in bytes. Default is @code{2930}.
1638 @item mpegts_flags @var{flags}
1639 Set mpegts flags. Accepts the following options:
1641 @item resend_headers
1642 Reemit PAT/PMT before writing the next packet.
1644 Use LATM packetization for AAC.
1645 @item pat_pmt_at_frames
1646 Reemit PAT and PMT at each video frame.
1648 Conform to System B (DVB) instead of System A (ATSC).
1649 @item initial_discontinuity
1650 Mark the initial packet of each stream as discontinuity.
1653 @item mpegts_copyts @var{boolean}
1654 Preserve original timestamps, if value is set to @code{1}. Default value
1655 is @code{-1}, which results in shifting timestamps so that they start from 0.
1657 @item omit_video_pes_length @var{boolean}
1658 Omit the PES packet length for video packets. Default is @code{1} (true).
1660 @item pcr_period @var{integer}
1661 Override the default PCR retransmission time in milliseconds. Default is
1662 @code{-1} which means that the PCR interval will be determined automatically:
1663 20 ms is used for CBR streams, the highest multiple of the frame duration which
1664 is less than 100 ms is used for VBR streams.
1666 @item pat_period @var{duration}
1667 Maximum time in seconds between PAT/PMT tables. Default is @code{0.1}.
1669 @item sdt_period @var{duration}
1670 Maximum time in seconds between SDT tables. Default is @code{0.5}.
1672 @item tables_version @var{integer}
1673 Set PAT, PMT and SDT version (default @code{0}, valid values are from 0 to 31, inclusively).
1674 This option allows updating stream structure so that standard consumer may
1675 detect the change. To do so, reopen output @code{AVFormatContext} (in case of API
1676 usage) or restart @command{ffmpeg} instance, cyclically changing
1677 @option{tables_version} value:
1680 ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
1681 ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
1683 ffmpeg -i source3.ts -codec copy -f mpegts -tables_version 31 udp://1.1.1.1:1111
1684 ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
1685 ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
1693 ffmpeg -i file.mpg -c copy \
1694 -mpegts_original_network_id 0x1122 \
1695 -mpegts_transport_stream_id 0x3344 \
1696 -mpegts_service_id 0x5566 \
1697 -mpegts_pmt_start_pid 0x1500 \
1698 -mpegts_start_pid 0x150 \
1699 -metadata service_provider="Some provider" \
1700 -metadata service_name="Some Channel" \
1704 @section mxf, mxf_d10, mxf_opatom
1710 The muxer options are:
1713 @item store_user_comments @var{bool}
1714 Set if user comments should be stored if available or never.
1715 IRT D-10 does not allow user comments. The default is thus to write them for
1716 mxf and mxf_opatom but not for mxf_d10
1723 This muxer does not generate any output file, it is mainly useful for
1724 testing or benchmarking purposes.
1726 For example to benchmark decoding with @command{ffmpeg} you can use the
1729 ffmpeg -benchmark -i INPUT -f null out.null
1732 Note that the above command does not read or write the @file{out.null}
1733 file, but specifying the output file is required by the @command{ffmpeg}
1736 Alternatively you can write the command as:
1738 ffmpeg -benchmark -i INPUT -f null -
1744 @item -syncpoints @var{flags}
1745 Change the syncpoint usage in nut:
1747 @item @var{default} use the normal low-overhead seeking aids.
1748 @item @var{none} do not use the syncpoints at all, reducing the overhead but making the stream non-seekable;
1749 Use of this option is not recommended, as the resulting files are very damage
1750 sensitive and seeking is not possible. Also in general the overhead from
1751 syncpoints is negligible. Note, -@code{write_index} 0 can be used to disable
1752 all growing data tables, allowing to mux endless streams with limited memory
1753 and without these disadvantages.
1754 @item @var{timestamped} extend the syncpoint with a wallclock field.
1756 The @var{none} and @var{timestamped} flags are experimental.
1757 @item -write_index @var{bool}
1758 Write index at the end, the default is to write an index.
1762 ffmpeg -i INPUT -f_strict experimental -syncpoints none - | processor
1767 Ogg container muxer.
1770 @item -page_duration @var{duration}
1771 Preferred page duration, in microseconds. The muxer will attempt to create
1772 pages that are approximately @var{duration} microseconds long. This allows the
1773 user to compromise between seek granularity and container overhead. The default
1774 is 1 second. A value of 0 will fill all segments, making pages as large as
1775 possible. A value of 1 will effectively use 1 packet-per-page in most
1776 situations, giving a small seek granularity at the cost of additional container
1778 @item -serial_offset @var{value}
1779 Serial value from which to set the streams serial number.
1780 Setting it to different and sufficiently large values ensures that the produced
1781 ogg files can be safely chained.
1786 @section segment, stream_segment, ssegment
1788 Basic stream segmenter.
1790 This muxer outputs streams to a number of separate files of nearly
1791 fixed duration. Output filename pattern can be set in a fashion
1792 similar to @ref{image2}, or by using a @code{strftime} template if
1793 the @option{strftime} option is enabled.
1795 @code{stream_segment} is a variant of the muxer used to write to
1796 streaming output formats, i.e. which do not require global headers,
1797 and is recommended for outputting e.g. to MPEG transport stream segments.
1798 @code{ssegment} is a shorter alias for @code{stream_segment}.
1800 Every segment starts with a keyframe of the selected reference stream,
1801 which is set through the @option{reference_stream} option.
1803 Note that if you want accurate splitting for a video file, you need to
1804 make the input key frames correspond to the exact splitting times
1805 expected by the segmenter, or the segment muxer will start the new
1806 segment with the key frame found next after the specified start
1809 The segment muxer works best with a single constant frame rate video.
1811 Optionally it can generate a list of the created segments, by setting
1812 the option @var{segment_list}. The list type is specified by the
1813 @var{segment_list_type} option. The entry filenames in the segment
1814 list are set by default to the basename of the corresponding segment
1817 See also the @ref{hls} muxer, which provides a more specific
1818 implementation for HLS segmentation.
1822 The segment muxer supports the following options:
1825 @item increment_tc @var{1|0}
1826 if set to @code{1}, increment timecode between each segment
1827 If this is selected, the input need to have
1828 a timecode in the first video stream. Default value is
1831 @item reference_stream @var{specifier}
1832 Set the reference stream, as specified by the string @var{specifier}.
1833 If @var{specifier} is set to @code{auto}, the reference is chosen
1834 automatically. Otherwise it must be a stream specifier (see the ``Stream
1835 specifiers'' chapter in the ffmpeg manual) which specifies the
1836 reference stream. The default value is @code{auto}.
1838 @item segment_format @var{format}
1839 Override the inner container format, by default it is guessed by the filename
1842 @item segment_format_options @var{options_list}
1843 Set output format options using a :-separated list of key=value
1844 parameters. Values containing the @code{:} special character must be
1847 @item segment_list @var{name}
1848 Generate also a listfile named @var{name}. If not specified no
1849 listfile is generated.
1851 @item segment_list_flags @var{flags}
1852 Set flags affecting the segment list generation.
1854 It currently supports the following flags:
1857 Allow caching (only affects M3U8 list files).
1860 Allow live-friendly file generation.
1863 @item segment_list_size @var{size}
1864 Update the list file so that it contains at most @var{size}
1865 segments. If 0 the list file will contain all the segments. Default
1868 @item segment_list_entry_prefix @var{prefix}
1869 Prepend @var{prefix} to each entry. Useful to generate absolute paths.
1870 By default no prefix is applied.
1872 @item segment_list_type @var{type}
1873 Select the listing format.
1875 The following values are recognized:
1878 Generate a flat list for the created segments, one segment per line.
1881 Generate a list for the created segments, one segment per line,
1882 each line matching the format (comma-separated values):
1884 @var{segment_filename},@var{segment_start_time},@var{segment_end_time}
1887 @var{segment_filename} is the name of the output file generated by the
1888 muxer according to the provided pattern. CSV escaping (according to
1889 RFC4180) is applied if required.
1891 @var{segment_start_time} and @var{segment_end_time} specify
1892 the segment start and end time expressed in seconds.
1894 A list file with the suffix @code{".csv"} or @code{".ext"} will
1895 auto-select this format.
1897 @samp{ext} is deprecated in favor or @samp{csv}.
1900 Generate an ffconcat file for the created segments. The resulting file
1901 can be read using the FFmpeg @ref{concat} demuxer.
1903 A list file with the suffix @code{".ffcat"} or @code{".ffconcat"} will
1904 auto-select this format.
1907 Generate an extended M3U8 file, version 3, compliant with
1908 @url{http://tools.ietf.org/id/draft-pantos-http-live-streaming}.
1910 A list file with the suffix @code{".m3u8"} will auto-select this format.
1913 If not specified the type is guessed from the list file name suffix.
1915 @item segment_time @var{time}
1916 Set segment duration to @var{time}, the value must be a duration
1917 specification. Default value is "2". See also the
1918 @option{segment_times} option.
1920 Note that splitting may not be accurate, unless you force the
1921 reference stream key-frames at the given time. See the introductory
1922 notice and the examples below.
1924 @item segment_atclocktime @var{1|0}
1925 If set to "1" split at regular clock time intervals starting from 00:00
1926 o'clock. The @var{time} value specified in @option{segment_time} is
1927 used for setting the length of the splitting interval.
1929 For example with @option{segment_time} set to "900" this makes it possible
1930 to create files at 12:00 o'clock, 12:15, 12:30, etc.
1932 Default value is "0".
1934 @item segment_clocktime_offset @var{duration}
1935 Delay the segment splitting times with the specified duration when using
1936 @option{segment_atclocktime}.
1938 For example with @option{segment_time} set to "900" and
1939 @option{segment_clocktime_offset} set to "300" this makes it possible to
1940 create files at 12:05, 12:20, 12:35, etc.
1942 Default value is "0".
1944 @item segment_clocktime_wrap_duration @var{duration}
1945 Force the segmenter to only start a new segment if a packet reaches the muxer
1946 within the specified duration after the segmenting clock time. This way you
1947 can make the segmenter more resilient to backward local time jumps, such as
1948 leap seconds or transition to standard time from daylight savings time.
1950 Default is the maximum possible duration which means starting a new segment
1951 regardless of the elapsed time since the last clock time.
1953 @item segment_time_delta @var{delta}
1954 Specify the accuracy time when selecting the start time for a
1955 segment, expressed as a duration specification. Default value is "0".
1957 When delta is specified a key-frame will start a new segment if its
1958 PTS satisfies the relation:
1960 PTS >= start_time - time_delta
1963 This option is useful when splitting video content, which is always
1964 split at GOP boundaries, in case a key frame is found just before the
1965 specified split time.
1967 In particular may be used in combination with the @file{ffmpeg} option
1968 @var{force_key_frames}. The key frame times specified by
1969 @var{force_key_frames} may not be set accurately because of rounding
1970 issues, with the consequence that a key frame time may result set just
1971 before the specified time. For constant frame rate videos a value of
1972 1/(2*@var{frame_rate}) should address the worst case mismatch between
1973 the specified time and the time set by @var{force_key_frames}.
1975 @item segment_times @var{times}
1976 Specify a list of split points. @var{times} contains a list of comma
1977 separated duration specifications, in increasing order. See also
1978 the @option{segment_time} option.
1980 @item segment_frames @var{frames}
1981 Specify a list of split video frame numbers. @var{frames} contains a
1982 list of comma separated integer numbers, in increasing order.
1984 This option specifies to start a new segment whenever a reference
1985 stream key frame is found and the sequential number (starting from 0)
1986 of the frame is greater or equal to the next value in the list.
1988 @item segment_wrap @var{limit}
1989 Wrap around segment index once it reaches @var{limit}.
1991 @item segment_start_number @var{number}
1992 Set the sequence number of the first segment. Defaults to @code{0}.
1994 @item strftime @var{1|0}
1995 Use the @code{strftime} function to define the name of the new
1996 segments to write. If this is selected, the output segment name must
1997 contain a @code{strftime} function template. Default value is
2000 @item break_non_keyframes @var{1|0}
2001 If enabled, allow segments to start on frames other than keyframes. This
2002 improves behavior on some players when the time between keyframes is
2003 inconsistent, but may make things worse on others, and can cause some oddities
2004 during seeking. Defaults to @code{0}.
2006 @item reset_timestamps @var{1|0}
2007 Reset timestamps at the beginning of each segment, so that each segment
2008 will start with near-zero timestamps. It is meant to ease the playback
2009 of the generated segments. May not work with some combinations of
2010 muxers/codecs. It is set to @code{0} by default.
2012 @item initial_offset @var{offset}
2013 Specify timestamp offset to apply to the output packet timestamps. The
2014 argument must be a time duration specification, and defaults to 0.
2016 @item write_empty_segments @var{1|0}
2017 If enabled, write an empty segment if there are no packets during the period a
2018 segment would usually span. Otherwise, the segment will be filled with the next
2019 packet written. Defaults to @code{0}.
2022 Make sure to require a closed GOP when encoding and to set the GOP
2023 size to fit your segment time constraint.
2025 @subsection Examples
2029 Remux the content of file @file{in.mkv} to a list of segments
2030 @file{out-000.nut}, @file{out-001.nut}, etc., and write the list of
2031 generated segments to @file{out.list}:
2033 ffmpeg -i in.mkv -codec hevc -flags +cgop -g 60 -map 0 -f segment -segment_list out.list out%03d.nut
2037 Segment input and set output format options for the output segments:
2039 ffmpeg -i in.mkv -f segment -segment_time 10 -segment_format_options movflags=+faststart out%03d.mp4
2043 Segment the input file according to the split points specified by the
2044 @var{segment_times} option:
2046 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
2050 Use the @command{ffmpeg} @option{force_key_frames}
2051 option to force key frames in the input at the specified location, together
2052 with the segment option @option{segment_time_delta} to account for
2053 possible roundings operated when setting key frame times.
2055 ffmpeg -i in.mkv -force_key_frames 1,2,3,5,8,13,21 -codec:v mpeg4 -codec:a pcm_s16le -map 0 \
2056 -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 -segment_time_delta 0.05 out%03d.nut
2058 In order to force key frames on the input file, transcoding is
2062 Segment the input file by splitting the input file according to the
2063 frame numbers sequence specified with the @option{segment_frames} option:
2065 ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_frames 100,200,300,500,800 out%03d.nut
2069 Convert the @file{in.mkv} to TS segments using the @code{libx264}
2070 and @code{aac} encoders:
2072 ffmpeg -i in.mkv -map 0 -codec:v libx264 -codec:a aac -f ssegment -segment_list out.list out%03d.ts
2076 Segment the input file, and create an M3U8 live playlist (can be used
2077 as live HLS source):
2079 ffmpeg -re -i in.mkv -codec copy -map 0 -f segment -segment_list playlist.m3u8 \
2080 -segment_list_flags +live -segment_time 10 out%03d.mkv
2084 @section smoothstreaming
2086 Smooth Streaming muxer generates a set of files (Manifest, chunks) suitable for serving with conventional web server.
2090 Specify the number of fragments kept in the manifest. Default 0 (keep all).
2092 @item extra_window_size
2093 Specify the number of fragments kept outside of the manifest before removing from disk. Default 5.
2095 @item lookahead_count
2096 Specify the number of lookahead fragments. Default 2.
2098 @item min_frag_duration
2099 Specify the minimum fragment duration (in microseconds). Default 5000000.
2101 @item remove_at_exit
2102 Specify whether to remove all fragments when finished. Default 0 (do not remove).
2109 Per stream hash testing format.
2111 This muxer computes and prints a cryptographic hash of all the input frames,
2112 on a per-stream basis. This can be used for equality checks without having
2113 to do a complete binary comparison.
2115 By default audio frames are converted to signed 16-bit raw audio and
2116 video frames to raw video before computing the hash, but the output
2117 of explicit conversions to other codecs can also be used. Timestamps
2118 are ignored. It uses the SHA-256 cryptographic hash function by default,
2119 but supports several other algorithms.
2121 The output of the muxer consists of one line per stream of the form:
2122 @var{streamindex},@var{streamtype},@var{algo}=@var{hash}, where
2123 @var{streamindex} is the index of the mapped stream, @var{streamtype} is a
2124 single character indicating the type of stream, @var{algo} is a short string
2125 representing the hash function used, and @var{hash} is a hexadecimal number
2126 representing the computed hash.
2129 @item hash @var{algorithm}
2130 Use the cryptographic hash function specified by the string @var{algorithm}.
2131 Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
2132 @code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
2133 @code{SHA224}, @code{SHA256} (default), @code{SHA512/224}, @code{SHA512/256},
2134 @code{SHA384}, @code{SHA512}, @code{CRC32} and @code{adler32}.
2138 @subsection Examples
2140 To compute the SHA-256 hash of the input converted to raw audio and
2141 video, and store it in the file @file{out.sha256}:
2143 ffmpeg -i INPUT -f streamhash out.sha256
2146 To print an MD5 hash to stdout use the command:
2148 ffmpeg -i INPUT -f streamhash -hash md5 -
2151 See also the @ref{hash} and @ref{framehash} muxers.
2156 The fifo pseudo-muxer allows the separation of encoding and muxing by using
2157 first-in-first-out queue and running the actual muxer in a separate thread. This
2158 is especially useful in combination with the @ref{tee} muxer and can be used to
2159 send data to several destinations with different reliability/writing speed/latency.
2161 API users should be aware that callback functions (interrupt_callback,
2162 io_open and io_close) used within its AVFormatContext must be thread-safe.
2164 The behavior of the fifo muxer if the queue fills up or if the output fails is
2170 output can be transparently restarted with configurable delay between retries
2171 based on real time or time of the processed stream.
2174 encoding can be blocked during temporary failure, or continue transparently
2175 dropping packets in case fifo queue fills up.
2182 Specify the format name. Useful if it cannot be guessed from the
2186 Specify size of the queue (number of packets). Default value is 60.
2189 Specify format options for the underlying muxer. Muxer options can be specified
2190 as a list of @var{key}=@var{value} pairs separated by ':'.
2192 @item drop_pkts_on_overflow @var{bool}
2193 If set to 1 (true), in case the fifo queue fills up, packets will be dropped
2194 rather than blocking the encoder. This makes it possible to continue streaming without
2195 delaying the input, at the cost of omitting part of the stream. By default
2196 this option is set to 0 (false), so in such cases the encoder will be blocked
2197 until the muxer processes some of the packets and none of them is lost.
2199 @item attempt_recovery @var{bool}
2200 If failure occurs, attempt to recover the output. This is especially useful
2201 when used with network output, since it makes it possible to restart streaming transparently.
2202 By default this option is set to 0 (false).
2204 @item max_recovery_attempts
2205 Sets maximum number of successive unsuccessful recovery attempts after which
2206 the output fails permanently. By default this option is set to 0 (unlimited).
2208 @item recovery_wait_time @var{duration}
2209 Waiting time before the next recovery attempt after previous unsuccessful
2210 recovery attempt. Default value is 5 seconds.
2212 @item recovery_wait_streamtime @var{bool}
2213 If set to 0 (false), the real time is used when waiting for the recovery
2214 attempt (i.e. the recovery will be attempted after at least
2215 recovery_wait_time seconds).
2216 If set to 1 (true), the time of the processed stream is taken into account
2217 instead (i.e. the recovery will be attempted after at least @var{recovery_wait_time}
2218 seconds of the stream is omitted).
2219 By default, this option is set to 0 (false).
2221 @item recover_any_error @var{bool}
2222 If set to 1 (true), recovery will be attempted regardless of type of the error
2223 causing the failure. By default this option is set to 0 (false) and in case of
2224 certain (usually permanent) errors the recovery is not attempted even when
2225 @var{attempt_recovery} is set to 1.
2227 @item restart_with_keyframe @var{bool}
2228 Specify whether to wait for the keyframe after recovering from
2229 queue overflow or failure. This option is set to 0 (false) by default.
2233 @subsection Examples
2238 Stream something to rtmp server, continue processing the stream at real-time
2239 rate even in case of temporary failure (network outage) and attempt to recover
2240 streaming every second indefinitely.
2242 ffmpeg -re -i ... -c:v libx264 -c:a aac -f fifo -fifo_format flv -map 0:v -map 0:a
2243 -drop_pkts_on_overflow 1 -attempt_recovery 1 -recovery_wait_time 1 rtmp://example.com/live/stream_name
2251 The tee muxer can be used to write the same data to several outputs, such as files or streams.
2252 It can be used, for example, to stream a video over a network and save it to disk at the same time.
2254 It is different from specifying several outputs to the @command{ffmpeg}
2255 command-line tool. With the tee muxer, the audio and video data will be encoded only once.
2256 With conventional multiple outputs, multiple encoding operations in parallel are initiated,
2257 which can be a very expensive process. The tee muxer is not useful when using the libavformat API
2258 directly because it is then possible to feed the same packets to several muxers directly.
2260 Since the tee muxer does not represent any particular output format, ffmpeg cannot auto-select
2261 output streams. So all streams intended for output must be specified using @code{-map}. See
2264 Some encoders may need different options depending on the output format;
2265 the auto-detection of this can not work with the tee muxer, so they need to be explicitly specified.
2266 The main example is the @option{global_header} flag.
2268 The slave outputs are specified in the file name given to the muxer,
2269 separated by '|'. If any of the slave name contains the '|' separator,
2270 leading or trailing spaces or any special character, those must be
2271 escaped (see @ref{quoting_and_escaping,,the "Quoting and escaping"
2272 section in the ffmpeg-utils(1) manual,ffmpeg-utils}).
2278 @item use_fifo @var{bool}
2279 If set to 1, slave outputs will be processed in separate threads using the @ref{fifo}
2280 muxer. This allows to compensate for different speed/latency/reliability of
2281 outputs and setup transparent recovery. By default this feature is turned off.
2284 Options to pass to fifo pseudo-muxer instances. See @ref{fifo}.
2288 Muxer options can be specified for each slave by prepending them as a list of
2289 @var{key}=@var{value} pairs separated by ':', between square brackets. If
2290 the options values contain a special character or the ':' separator, they
2291 must be escaped; note that this is a second level escaping.
2293 The following special options are also recognized:
2296 Specify the format name. Required if it cannot be guessed from the
2299 @item bsfs[/@var{spec}]
2300 Specify a list of bitstream filters to apply to the specified
2303 It is possible to specify to which streams a given bitstream filter
2304 applies, by appending a stream specifier to the option separated by
2305 @code{/}. @var{spec} must be a stream specifier (see @ref{Format
2306 stream specifiers}).
2308 If the stream specifier is not specified, the bitstream filters will be
2309 applied to all streams in the output. This will cause that output operation
2310 to fail if the output contains streams to which the bitstream filter cannot
2311 be applied e.g. @code{h264_mp4toannexb} being applied to an output containing an audio stream.
2313 Options for a bitstream filter must be specified in the form of @code{opt=value}.
2315 Several bitstream filters can be specified, separated by ",".
2317 @item use_fifo @var{bool}
2318 This allows to override tee muxer use_fifo option for individual slave muxer.
2321 This allows to override tee muxer fifo_options for individual slave muxer.
2325 Select the streams that should be mapped to the slave output,
2326 specified by a stream specifier. If not specified, this defaults to
2327 all the mapped streams. This will cause that output operation to fail
2328 if the output format does not accept all mapped streams.
2330 You may use multiple stream specifiers separated by commas (@code{,}) e.g.: @code{a:0,v}
2333 Specify behaviour on output failure. This can be set to either @code{abort} (which is
2334 default) or @code{ignore}. @code{abort} will cause whole process to fail in case of failure
2335 on this slave output. @code{ignore} will ignore failure on this output, so other outputs
2336 will continue without being affected.
2339 @subsection Examples
2343 Encode something and both archive it in a WebM file and stream it
2344 as MPEG-TS over UDP:
2346 ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
2347 "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
2351 As above, but continue streaming even if output to local file fails
2352 (for example local drive fills up):
2354 ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
2355 "[onfail=ignore]archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
2359 Use @command{ffmpeg} to encode the input, and send the output
2360 to three different destinations. The @code{dump_extra} bitstream
2361 filter is used to add extradata information to all the output video
2362 keyframes packets, as requested by the MPEG-TS format. The select
2363 option is applied to @file{out.aac} in order to make it contain only
2366 ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
2367 -f tee "[bsfs/v=dump_extra=freq=keyframe]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac"
2371 As above, but select only stream @code{a:1} for the audio output. Note
2372 that a second level escaping must be performed, as ":" is a special
2373 character used to separate options.
2375 ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
2376 -f tee "[bsfs/v=dump_extra=freq=keyframe]out.ts|[movflags=+faststart]out.mp4|[select=\'a:1\']out.aac"
2380 @section webm_dash_manifest
2382 WebM DASH Manifest muxer.
2384 This muxer implements the WebM DASH Manifest specification to generate the DASH
2385 manifest XML. It also supports manifest generation for DASH live streams.
2387 For more information see:
2391 WebM DASH Specification: @url{https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification}
2393 ISO DASH Specification: @url{http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip}
2398 This muxer supports the following options:
2401 @item adaptation_sets
2402 This option has the following syntax: "id=x,streams=a,b,c id=y,streams=d,e" where x and y are the
2403 unique identifiers of the adaptation sets and a,b,c,d and e are the indices of the corresponding
2404 audio and video streams. Any number of adaptation sets can be added using this option.
2407 Set this to 1 to create a live stream DASH Manifest. Default: 0.
2409 @item chunk_start_index
2410 Start index of the first chunk. This will go in the @samp{startNumber} attribute
2411 of the @samp{SegmentTemplate} element in the manifest. Default: 0.
2413 @item chunk_duration_ms
2414 Duration of each chunk in milliseconds. This will go in the @samp{duration}
2415 attribute of the @samp{SegmentTemplate} element in the manifest. Default: 1000.
2417 @item utc_timing_url
2418 URL of the page that will return the UTC timestamp in ISO format. This will go
2419 in the @samp{value} attribute of the @samp{UTCTiming} element in the manifest.
2422 @item time_shift_buffer_depth
2423 Smallest time (in seconds) shifting buffer for which any Representation is
2424 guaranteed to be available. This will go in the @samp{timeShiftBufferDepth}
2425 attribute of the @samp{MPD} element. Default: 60.
2427 @item minimum_update_period
2428 Minimum update period (in seconds) of the manifest. This will go in the
2429 @samp{minimumUpdatePeriod} attribute of the @samp{MPD} element. Default: 0.
2435 ffmpeg -f webm_dash_manifest -i video1.webm \
2436 -f webm_dash_manifest -i video2.webm \
2437 -f webm_dash_manifest -i audio1.webm \
2438 -f webm_dash_manifest -i audio2.webm \
2439 -map 0 -map 1 -map 2 -map 3 \
2441 -f webm_dash_manifest \
2442 -adaptation_sets "id=0,streams=0,1 id=1,streams=2,3" \
2448 WebM Live Chunk Muxer.
2450 This muxer writes out WebM headers and chunks as separate files which can be
2451 consumed by clients that support WebM Live streams via DASH.
2455 This muxer supports the following options:
2458 @item chunk_start_index
2459 Index of the first chunk (defaults to 0).
2462 Filename of the header where the initialization data will be written.
2464 @item audio_chunk_duration
2465 Duration of each audio chunk in milliseconds (defaults to 5000).
2470 ffmpeg -f v4l2 -i /dev/video0 \
2474 -s 640x360 -keyint_min 30 -g 30 \
2476 -header webm_live_video_360.hdr \
2477 -chunk_start_index 1 \
2478 webm_live_video_360_%d.chk \
2483 -header webm_live_audio_128.hdr \
2484 -chunk_start_index 1 \
2485 -audio_chunk_duration 1000 \
2486 webm_live_audio_128_%d.chk