4 Muxers are configured elements in FFmpeg which allow writing
5 multimedia streams to a particular type of file.
7 When you configure your FFmpeg build, all the supported muxers
8 are enabled by default. You can list all available muxers using the
9 configure option @code{--list-muxers}.
11 You can disable all the muxers with the configure option
12 @code{--disable-muxers} and selectively enable / disable single muxers
13 with the options @code{--enable-muxer=@var{MUXER}} /
14 @code{--disable-muxer=@var{MUXER}}.
16 The option @code{-formats} of the ff* tools will display the list of
19 A description of some of the currently available muxers follows.
24 Audio Interchange File Format muxer.
28 It accepts the following options:
32 Enable ID3v2 tags writing when set to 1. Default is 0 (disabled).
35 Select ID3v2 version to write. Currently only version 3 and 4 (aka.
36 ID3v2.3 and ID3v2.4) are supported. The default is version 4.
43 CRC (Cyclic Redundancy Check) testing format.
45 This muxer computes and prints the Adler-32 CRC of all the input audio
46 and video frames. By default audio frames are converted to signed
47 16-bit raw audio and video frames to raw video before computing the
50 The output of the muxer consists of a single line of the form:
51 CRC=0x@var{CRC}, where @var{CRC} is a hexadecimal number 0-padded to
52 8 digits containing the CRC for all the decoded input frames.
54 See also the @ref{framecrc} muxer.
58 For example to compute the CRC of the input, and store it in the file
61 ffmpeg -i INPUT -f crc out.crc
64 You can print the CRC to stdout with the command:
66 ffmpeg -i INPUT -f crc -
69 You can select the output format of each frame with @command{ffmpeg} by
70 specifying the audio and video codec and format. For example to
71 compute the CRC of the input audio converted to PCM unsigned 8-bit
72 and the input video converted to MPEG-2 video, use the command:
74 ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc -
80 Per-packet CRC (Cyclic Redundancy Check) testing format.
82 This muxer computes and prints the Adler-32 CRC for each audio
83 and video packet. By default audio frames are converted to signed
84 16-bit raw audio and video frames to raw video before computing the
87 The output of the muxer consists of a line for each audio and video
90 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, 0x@var{CRC}
93 @var{CRC} is a hexadecimal number 0-padded to 8 digits containing the
98 For example to compute the CRC of the audio and video frames in
99 @file{INPUT}, converted to raw audio and video packets, and store it
100 in the file @file{out.crc}:
102 ffmpeg -i INPUT -f framecrc out.crc
105 To print the information to stdout, use the command:
107 ffmpeg -i INPUT -f framecrc -
110 With @command{ffmpeg}, you can select the output format to which the
111 audio and video frames are encoded before computing the CRC for each
112 packet by specifying the audio and video codec. For example, to
113 compute the CRC of each decoded input audio frame converted to PCM
114 unsigned 8-bit and of each decoded input video frame converted to
115 MPEG-2 video, use the command:
117 ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -
120 See also the @ref{crc} muxer.
125 Per-packet MD5 testing format.
127 This muxer computes and prints the MD5 hash for each audio
128 and video packet. By default audio frames are converted to signed
129 16-bit raw audio and video frames to raw video before computing the
132 The output of the muxer consists of a line for each audio and video
135 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, @var{MD5}
138 @var{MD5} is a hexadecimal number representing the computed MD5 hash
143 For example to compute the MD5 of the audio and video frames in
144 @file{INPUT}, converted to raw audio and video packets, and store it
145 in the file @file{out.md5}:
147 ffmpeg -i INPUT -f framemd5 out.md5
150 To print the information to stdout, use the command:
152 ffmpeg -i INPUT -f framemd5 -
155 See also the @ref{md5} muxer.
162 It accepts the following options:
166 Set the number of times to loop the output. Use @code{-1} for no loop, @code{0}
167 for looping indefinitely (default).
170 Force the delay (expressed in centiseconds) after the last frame. Each frame
171 ends with a delay until the next frame. The default is @code{-1}, which is a
172 special value to tell the muxer to re-use the previous delay. In case of a
173 loop, you might want to customize this value to mark a pause for instance.
176 For example, to encode a gif looping 10 times, with a 5 seconds delay between
179 ffmpeg -i INPUT -loop 10 -final_delay 500 out.gif
182 Note 1: if you wish to extract the frames in separate GIF files, you need to
183 force the @ref{image2} muxer:
185 ffmpeg -i INPUT -c:v gif -f image2 "out%d.gif"
188 Note 2: the GIF format has a very small time base: the delay between two frames
189 can not be smaller than one centi second.
194 Apple HTTP Live Streaming muxer that segments MPEG-TS according to
195 the HTTP Live Streaming (HLS) specification.
197 It creates a playlist file, and one or more segment files. The output filename
198 specifies the playlist filename.
200 By default, the muxer creates a file for each segment produced. These files
201 have the same name as the playlist, followed by a sequential number and a
204 For example, to convert an input file with @command{ffmpeg}:
206 ffmpeg -i in.nut out.m3u8
208 This example will produce the playlist, @file{out.m3u8}, and segment files:
209 @file{out0.ts}, @file{out1.ts}, @file{out2.ts}, etc.
211 See also the @ref{segment} muxer, which provides a more generic and
212 flexible implementation of a segmenter, and can be used to perform HLS
217 This muxer supports the following options:
220 @item hls_time @var{seconds}
221 Set the segment length in seconds. Default value is 2.
223 @item hls_list_size @var{size}
224 Set the maximum number of playlist entries. If set to 0 the list file
225 will contain all the segments. Default value is 5.
227 @item hls_ts_options @var{options_list}
228 Set output format options using a :-separated list of key=value
229 parameters. Values containing @code{:} special characters must be
232 @item hls_wrap @var{wrap}
233 Set the number after which the segment filename number (the number
234 specified in each segment file) wraps. If set to 0 the number will be
235 never wrapped. Default value is 0.
237 This option is useful to avoid to fill the disk with many segment
238 files, and limits the maximum number of segment files written to disk
241 @item start_number @var{number}
242 Start the playlist sequence number from @var{number}. Default value is
245 @item hls_allow_cache @var{allowcache}
246 Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments.
248 @item hls_base_url @var{baseurl}
249 Append @var{baseurl} to every entry in the playlist.
250 Useful to generate playlists with absolute paths.
252 Note that the playlist sequence number must be unique for each segment
253 and it is not to be confused with the segment filename sequence number
254 which can be cyclic, for example if the @option{wrap} option is
257 @item hls_segment_filename @var{filename}
258 Set the segment filename. Unless hls_flags single_file is set @var{filename}
259 is used as a string format with the segment number:
261 ffmpeg in.nut -hls_segment_filename 'file%03d.ts' out.m3u8
263 This example will produce the playlist, @file{out.m3u8}, and segment files:
264 @file{file000.ts}, @file{file001.ts}, @file{file002.ts}, etc.
266 @item hls_key_info_file @var{key_info_file}
267 Use the information in @var{key_info_file} for segment encryption. The first
268 line of @var{key_info_file} specifies the key URI written to the playlist. The
269 key URL is used to access the encryption key during playback. The second line
270 specifies the path to the key file used to obtain the key during the encryption
271 process. The key file is read as a single packed array of 16 octets in binary
272 format. The optional third line specifies the initialization vector (IV) as a
273 hexadecimal string to be used instead of the segment sequence number (default)
274 for encryption. Changes to @var{key_info_file} will result in segment
275 encryption with the new key/IV and an entry in the playlist for the new key
278 Key info file format:
287 http://server/file.key
292 Example key file paths:
300 0123456789ABCDEF0123456789ABCDEF
303 Key info file example:
305 http://server/file.key
307 0123456789ABCDEF0123456789ABCDEF
310 Example shell script:
314 openssl rand 16 > file.key
315 echo $BASE_URL/file.key > file.keyinfo
316 echo file.key >> file.keyinfo
317 echo $(openssl rand -hex 16) >> file.keyinfo
318 ffmpeg -f lavfi -re -i testsrc -c:v h264 -hls_flags delete_segments \
319 -hls_key_info_file file.keyinfo out.m3u8
322 @item hls_flags single_file
323 If this flag is set, the muxer will store all segments in a single MPEG-TS
324 file, and will use byte ranges in the playlist. HLS playlists generated with
325 this way will have the version number 4.
328 ffmpeg -i in.nut -hls_flags single_file out.m3u8
330 Will produce the playlist, @file{out.m3u8}, and a single segment file,
333 @item hls_flags delete_segments
334 Segment files removed from the playlist are deleted after a period of time
335 equal to the duration of the segment plus the duration of the playlist.
343 Microsoft's icon file format (ICO) has some strict limitations that should be noted:
347 Size cannot exceed 256 pixels in any dimension
350 Only BMP and PNG images can be stored
353 If a BMP image is used, it must be one of the following pixel formats:
355 BMP Bit Depth FFmpeg Pixel Format
365 If a BMP image is used, it must use the BITMAPINFOHEADER DIB header
368 If a PNG image is used, it must use the rgba pixel format
376 The image file muxer writes video frames to image files.
378 The output filenames are specified by a pattern, which can be used to
379 produce sequentially numbered series of files.
380 The pattern may contain the string "%d" or "%0@var{N}d", this string
381 specifies the position of the characters representing a numbering in
382 the filenames. If the form "%0@var{N}d" is used, the string
383 representing the number in each filename is 0-padded to @var{N}
384 digits. The literal character '%' can be specified in the pattern with
387 If the pattern contains "%d" or "%0@var{N}d", the first filename of
388 the file list specified will contain the number 1, all the following
389 numbers will be sequential.
391 The pattern may contain a suffix which is used to automatically
392 determine the format of the image files to write.
394 For example the pattern "img-%03d.bmp" will specify a sequence of
395 filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ...,
396 @file{img-010.bmp}, etc.
397 The pattern "img%%-%d.jpg" will specify a sequence of filenames of the
398 form @file{img%-1.jpg}, @file{img%-2.jpg}, ..., @file{img%-10.jpg},
403 The following example shows how to use @command{ffmpeg} for creating a
404 sequence of files @file{img-001.jpeg}, @file{img-002.jpeg}, ...,
405 taking one image every second from the input video:
407 ffmpeg -i in.avi -vsync 1 -r 1 -f image2 'img-%03d.jpeg'
410 Note that with @command{ffmpeg}, if the format is not specified with the
411 @code{-f} option and the output filename specifies an image file
412 format, the image2 muxer is automatically selected, so the previous
413 command can be written as:
415 ffmpeg -i in.avi -vsync 1 -r 1 'img-%03d.jpeg'
418 Note also that the pattern must not necessarily contain "%d" or
419 "%0@var{N}d", for example to create a single image file
420 @file{img.jpeg} from the input video you can employ the command:
422 ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg
425 The @option{strftime} option allows you to expand the filename with
426 date and time information. Check the documentation of
427 the @code{strftime()} function for the syntax.
429 For example to generate image files from the @code{strftime()}
430 "%Y-%m-%d_%H-%M-%S" pattern, the following @command{ffmpeg} command
433 ffmpeg -f v4l2 -r 1 -i /dev/video0 -f image2 -strftime 1 "%Y-%m-%d_%H-%M-%S.jpg"
440 Start the sequence from the specified number. Default value is 0.
443 If set to 1, the filename will always be interpreted as just a
444 filename, not a pattern, and the corresponding file will be continuously
445 overwritten with new images. Default value is 0.
448 If set to 1, expand the filename with date and time information from
449 @code{strftime()}. Default value is 0.
452 The image muxer supports the .Y.U.V image file format. This format is
453 special in that that each image frame consists of three files, for
454 each of the YUV420P components. To read or write this image file format,
455 specify the name of the '.Y' file. The muxer will automatically open the
456 '.U' and '.V' files as required.
460 Matroska container muxer.
462 This muxer implements the matroska and webm container specs.
466 The recognized metadata settings in this muxer are:
470 Set title name provided to a single track.
473 Specify the language of the track in the Matroska languages form.
475 The language can be either the 3 letters bibliographic ISO-639-2 (ISO
476 639-2/B) form (like "fre" for French), or a language code mixed with a
477 country code for specialities in languages (like "fre-ca" for Canadian
481 Set stereo 3D video layout of two views in a single video track.
483 The following values are recognized:
488 Both views are arranged side by side, Left-eye view is on the left
490 Both views are arranged in top-bottom orientation, Left-eye view is at bottom
492 Both views are arranged in top-bottom orientation, Left-eye view is on top
493 @item checkerboard_rl
494 Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first
495 @item checkerboard_lr
496 Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first
497 @item row_interleaved_rl
498 Each view is constituted by a row based interleaving, Right-eye view is first row
499 @item row_interleaved_lr
500 Each view is constituted by a row based interleaving, Left-eye view is first row
501 @item col_interleaved_rl
502 Both views are arranged in a column based interleaving manner, Right-eye view is first column
503 @item col_interleaved_lr
504 Both views are arranged in a column based interleaving manner, Left-eye view is first column
505 @item anaglyph_cyan_red
506 All frames are in anaglyph format viewable through red-cyan filters
508 Both views are arranged side by side, Right-eye view is on the left
509 @item anaglyph_green_magenta
510 All frames are in anaglyph format viewable through green-magenta filters
512 Both eyes laced in one Block, Left-eye view is first
514 Both eyes laced in one Block, Right-eye view is first
518 For example a 3D WebM clip can be created using the following command line:
520 ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm
525 This muxer supports the following options:
528 @item reserve_index_space
529 By default, this muxer writes the index for seeking (called cues in Matroska
530 terms) at the end of the file, because it cannot know in advance how much space
531 to leave for the index at the beginning of the file. However for some use cases
532 -- e.g. streaming where seeking is possible but slow -- it is useful to put the
533 index at the beginning of the file.
535 If this option is set to a non-zero value, the muxer will reserve a given amount
536 of space in the file header and then try to write the cues there when the muxing
537 finishes. If the available space does not suffice, muxing will fail. A safe size
538 for most use cases should be about 50kB per hour of video.
540 Note that cues are only written if the output is seekable and this option will
541 have no effect if it is not.
549 This muxer computes and prints the MD5 hash of all the input audio
550 and video frames. By default audio frames are converted to signed
551 16-bit raw audio and video frames to raw video before computing the
554 The output of the muxer consists of a single line of the form:
555 MD5=@var{MD5}, where @var{MD5} is a hexadecimal number representing
556 the computed MD5 hash.
558 For example to compute the MD5 hash of the input converted to raw
559 audio and video, and store it in the file @file{out.md5}:
561 ffmpeg -i INPUT -f md5 out.md5
564 You can print the MD5 to stdout with the command:
566 ffmpeg -i INPUT -f md5 -
569 See also the @ref{framemd5} muxer.
571 @section mov, mp4, ismv
573 MOV/MP4/ISMV (Smooth Streaming) muxer.
575 The mov/mp4/ismv muxer supports fragmentation. Normally, a MOV/MP4
576 file has all the metadata about all packets stored in one location
577 (written at the end of the file, it can be moved to the start for
578 better playback by adding @var{faststart} to the @var{movflags}, or
579 using the @command{qt-faststart} tool). A fragmented
580 file consists of a number of fragments, where packets and metadata
581 about these packets are stored together. Writing a fragmented
582 file has the advantage that the file is decodable even if the
583 writing is interrupted (while a normal MOV/MP4 is undecodable if
584 it is not properly finished), and it requires less memory when writing
585 very long files (since writing normal MOV/MP4 files stores info about
586 every single packet in memory until the file is closed). The downside
587 is that it is less compatible with other applications.
591 Fragmentation is enabled by setting one of the AVOptions that define
592 how to cut the file into fragments:
595 @item -moov_size @var{bytes}
596 Reserves space for the moov atom at the beginning of the file instead of placing the
597 moov atom at the end. If the space reserved is insufficient, muxing will fail.
598 @item -movflags frag_keyframe
599 Start a new fragment at each video keyframe.
600 @item -frag_duration @var{duration}
601 Create fragments that are @var{duration} microseconds long.
602 @item -frag_size @var{size}
603 Create fragments that contain up to @var{size} bytes of payload data.
604 @item -movflags frag_custom
605 Allow the caller to manually choose when to cut fragments, by
606 calling @code{av_write_frame(ctx, NULL)} to write a fragment with
607 the packets written so far. (This is only useful with other
608 applications integrating libavformat, not from @command{ffmpeg}.)
609 @item -min_frag_duration @var{duration}
610 Don't create fragments that are shorter than @var{duration} microseconds long.
613 If more than one condition is specified, fragments are cut when
614 one of the specified conditions is fulfilled. The exception to this is
615 @code{-min_frag_duration}, which has to be fulfilled for any of the other
618 Additionally, the way the output file is written can be adjusted
619 through a few other options:
622 @item -movflags empty_moov
623 Write an initial moov atom directly at the start of the file, without
624 describing any samples in it. Generally, an mdat/moov pair is written
625 at the start of the file, as a normal MOV/MP4 file, containing only
626 a short portion of the file. With this option set, there is no initial
627 mdat atom, and the moov atom only describes the tracks but has
630 This option is implicitly set when writing ismv (Smooth Streaming) files.
631 @item -movflags separate_moof
632 Write a separate moof (movie fragment) atom for each track. Normally,
633 packets for all tracks are written in a moof atom (which is slightly
634 more efficient), but with this option set, the muxer writes one moof/mdat
635 pair for each track, making it easier to separate tracks.
637 This option is implicitly set when writing ismv (Smooth Streaming) files.
638 @item -movflags faststart
639 Run a second pass moving the index (moov atom) to the beginning of the file.
640 This operation can take a while, and will not work in various situations such
641 as fragmented output, thus it is not enabled by default.
642 @item -movflags rtphint
643 Add RTP hinting tracks to the output file.
644 @item -movflags disable_chpl
645 Disable Nero chapter markers (chpl atom). Normally, both Nero chapters
646 and a QuickTime chapter track are written to the file. With this option
647 set, only the QuickTime chapter track will be written. Nero chapters can
648 cause failures when the file is reprocessed with certain tagging programs, like
649 mp3Tag 2.61a and iTunes 11.3, most likely other versions are affected as well.
650 @item -movflags omit_tfhd_offset
651 Do not write any absolute base_data_offset in tfhd atoms. This avoids
652 tying fragments to absolute byte positions in the file/streams.
653 @item -movflags default_base_moof
654 Similarly to the omit_tfhd_offset, this flag avoids writing the
655 absolute base_data_offset field in tfhd atoms, but does so by using
656 the new default-base-is-moof flag instead. This flag is new from
657 14496-12:2012. This may make the fragments easier to parse in certain
658 circumstances (avoiding basing track fragment location calculations
659 on the implicit end of the previous track fragment).
664 Smooth Streaming content can be pushed in real time to a publishing
665 point on IIS with this muxer. Example:
667 ffmpeg -re @var{<normal input/transcoding options>} -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1)
672 The MP3 muxer writes a raw MP3 stream with the following optional features:
675 An ID3v2 metadata header at the beginning (enabled by default). Versions 2.3 and
676 2.4 are supported, the @code{id3v2_version} private option controls which one is
677 used (3 or 4). Setting @code{id3v2_version} to 0 disables the ID3v2 header
680 The muxer supports writing attached pictures (APIC frames) to the ID3v2 header.
681 The pictures are supplied to the muxer in form of a video stream with a single
682 packet. There can be any number of those streams, each will correspond to a
683 single APIC frame. The stream metadata tags @var{title} and @var{comment} map
684 to APIC @var{description} and @var{picture type} respectively. See
685 @url{http://id3.org/id3v2.4.0-frames} for allowed picture types.
687 Note that the APIC frames must be written at the beginning, so the muxer will
688 buffer the audio frames until it gets all the pictures. It is therefore advised
689 to provide the pictures as soon as possible to avoid excessive buffering.
692 A Xing/LAME frame right after the ID3v2 header (if present). It is enabled by
693 default, but will be written only if the output is seekable. The
694 @code{write_xing} private option can be used to disable it. The frame contains
695 various information that may be useful to the decoder, like the audio duration
699 A legacy ID3v1 tag at the end of the file (disabled by default). It may be
700 enabled with the @code{write_id3v1} private option, but as its capabilities are
701 very limited, its usage is not recommended.
706 Write an mp3 with an ID3v2.3 header and an ID3v1 footer:
708 ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3
711 To attach a picture to an mp3 file select both the audio and the picture stream
714 ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1
715 -metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3
718 Write a "clean" MP3 without any extra features:
720 ffmpeg -i input.wav -write_xing 0 -id3v2_version 0 out.mp3
725 MPEG transport stream muxer.
727 This muxer implements ISO 13818-1 and part of ETSI EN 300 468.
729 The recognized metadata settings in mpegts muxer are @code{service_provider}
730 and @code{service_name}. If they are not set the default for
731 @code{service_provider} is "FFmpeg" and the default for
732 @code{service_name} is "Service01".
736 The muxer options are:
739 @item -mpegts_original_network_id @var{number}
740 Set the original_network_id (default 0x0001). This is unique identifier
741 of a network in DVB. Its main use is in the unique identification of a
742 service through the path Original_Network_ID, Transport_Stream_ID.
743 @item -mpegts_transport_stream_id @var{number}
744 Set the transport_stream_id (default 0x0001). This identifies a
746 @item -mpegts_service_id @var{number}
747 Set the service_id (default 0x0001) also known as program in DVB.
748 @item -mpegts_service_type @var{number}
749 Set the program service_type (default @var{digital_tv}), see below
750 a list of pre defined values.
751 @item -mpegts_pmt_start_pid @var{number}
752 Set the first PID for PMT (default 0x1000, max 0x1f00).
753 @item -mpegts_start_pid @var{number}
754 Set the first PID for data packets (default 0x0100, max 0x0f00).
755 @item -mpegts_m2ts_mode @var{number}
756 Enable m2ts mode if set to 1. Default value is -1 which disables m2ts mode.
757 @item -muxrate @var{number}
758 Set a constant muxrate (default VBR).
759 @item -pcr_period @var{numer}
760 Override the default PCR retransmission time (default 20ms), ignored
761 if variable muxrate is selected.
762 @item -pes_payload_size @var{number}
763 Set minimum PES packet payload in bytes.
764 @item -mpegts_flags @var{flags}
765 Set flags (see below).
766 @item -mpegts_copyts @var{number}
767 Preserve original timestamps, if value is set to 1. Default value is -1, which
768 results in shifting timestamps so that they start from 0.
769 @item -tables_version @var{number}
770 Set PAT, PMT and SDT version (default 0, valid values are from 0 to 31, inclusively).
771 This option allows updating stream structure so that standard consumer may
772 detect the change. To do so, reopen output AVFormatContext (in case of API
773 usage) or restart ffmpeg instance, cyclically changing tables_version value:
775 ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
776 ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
778 ffmpeg -i source3.ts -codec copy -f mpegts -tables_version 31 udp://1.1.1.1:1111
779 ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
780 ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
785 Option mpegts_service_type accepts the following values:
789 Any hexdecimal value between 0x01 to 0xff as defined in ETSI 300 468.
793 Digital Radio service.
796 @item advanced_codec_digital_radio
797 Advanced Codec Digital Radio service.
798 @item mpeg2_digital_hdtv
799 MPEG2 Digital HDTV service.
800 @item advanced_codec_digital_sdtv
801 Advanced Codec Digital SDTV service.
802 @item advanced_codec_digital_hdtv
803 Advanced Codec Digital HDTV service.
806 Option mpegts_flags may take a set of such flags:
810 Reemit PAT/PMT before writing the next packet.
812 Use LATM packetization for AAC.
818 ffmpeg -i file.mpg -c copy \
819 -mpegts_original_network_id 0x1122 \
820 -mpegts_transport_stream_id 0x3344 \
821 -mpegts_service_id 0x5566 \
822 -mpegts_pmt_start_pid 0x1500 \
823 -mpegts_start_pid 0x150 \
824 -metadata service_provider="Some provider" \
825 -metadata service_name="Some Channel" \
833 This muxer does not generate any output file, it is mainly useful for
834 testing or benchmarking purposes.
836 For example to benchmark decoding with @command{ffmpeg} you can use the
839 ffmpeg -benchmark -i INPUT -f null out.null
842 Note that the above command does not read or write the @file{out.null}
843 file, but specifying the output file is required by the @command{ffmpeg}
846 Alternatively you can write the command as:
848 ffmpeg -benchmark -i INPUT -f null -
854 @item -syncpoints @var{flags}
855 Change the syncpoint usage in nut:
857 @item @var{default} use the normal low-overhead seeking aids.
858 @item @var{none} do not use the syncpoints at all, reducing the overhead but making the stream non-seekable;
859 Use of this option is not recommended, as the resulting files are very damage
860 sensitive and seeking is not possible. Also in general the overhead from
861 syncpoints is negligible. Note, -@code{write_index} 0 can be used to disable
862 all growing data tables, allowing to mux endless streams with limited memory
863 and without these disadvantages.
864 @item @var{timestamped} extend the syncpoint with a wallclock field.
866 The @var{none} and @var{timestamped} flags are experimental.
867 @item -write_index @var{bool}
868 Write index at the end, the default is to write an index.
872 ffmpeg -i INPUT -f_strict experimental -syncpoints none - | processor
880 @item -page_duration @var{duration}
881 Preferred page duration, in microseconds. The muxer will attempt to create
882 pages that are approximately @var{duration} microseconds long. This allows the
883 user to compromise between seek granularity and container overhead. The default
884 is 1 second. A value of 0 will fill all segments, making pages as large as
885 possible. A value of 1 will effectively use 1 packet-per-page in most
886 situations, giving a small seek granularity at the cost of additional container
888 @item -serial_offset @var{value}
889 Serial value from which to set the streams serial number.
890 Setting it to different and sufficiently large values ensures that the produced
891 ogg files can be safely chained.
896 @section segment, stream_segment, ssegment
898 Basic stream segmenter.
900 This muxer outputs streams to a number of separate files of nearly
901 fixed duration. Output filename pattern can be set in a fashion
902 similar to @ref{image2}, or by using a @code{strftime} template if
903 the @option{strftime} option is enabled.
905 @code{stream_segment} is a variant of the muxer used to write to
906 streaming output formats, i.e. which do not require global headers,
907 and is recommended for outputting e.g. to MPEG transport stream segments.
908 @code{ssegment} is a shorter alias for @code{stream_segment}.
910 Every segment starts with a keyframe of the selected reference stream,
911 which is set through the @option{reference_stream} option.
913 Note that if you want accurate splitting for a video file, you need to
914 make the input key frames correspond to the exact splitting times
915 expected by the segmenter, or the segment muxer will start the new
916 segment with the key frame found next after the specified start
919 The segment muxer works best with a single constant frame rate video.
921 Optionally it can generate a list of the created segments, by setting
922 the option @var{segment_list}. The list type is specified by the
923 @var{segment_list_type} option. The entry filenames in the segment
924 list are set by default to the basename of the corresponding segment
927 See also the @ref{hls} muxer, which provides a more specific
928 implementation for HLS segmentation.
932 The segment muxer supports the following options:
935 @item reference_stream @var{specifier}
936 Set the reference stream, as specified by the string @var{specifier}.
937 If @var{specifier} is set to @code{auto}, the reference is chosen
938 automatically. Otherwise it must be a stream specifier (see the ``Stream
939 specifiers'' chapter in the ffmpeg manual) which specifies the
940 reference stream. The default value is @code{auto}.
942 @item segment_format @var{format}
943 Override the inner container format, by default it is guessed by the filename
946 @item segment_format_options @var{options_list}
947 Set output format options using a :-separated list of key=value
948 parameters. Values containing the @code{:} special character must be
951 @item segment_list @var{name}
952 Generate also a listfile named @var{name}. If not specified no
953 listfile is generated.
955 @item segment_list_flags @var{flags}
956 Set flags affecting the segment list generation.
958 It currently supports the following flags:
961 Allow caching (only affects M3U8 list files).
964 Allow live-friendly file generation.
967 @item segment_list_size @var{size}
968 Update the list file so that it contains at most @var{size}
969 segments. If 0 the list file will contain all the segments. Default
972 @item segment_list_entry_prefix @var{prefix}
973 Prepend @var{prefix} to each entry. Useful to generate absolute paths.
974 By default no prefix is applied.
976 @item segment_list_type @var{type}
977 Select the listing format.
979 The following values are recognized:
982 Generate a flat list for the created segments, one segment per line.
985 Generate a list for the created segments, one segment per line,
986 each line matching the format (comma-separated values):
988 @var{segment_filename},@var{segment_start_time},@var{segment_end_time}
991 @var{segment_filename} is the name of the output file generated by the
992 muxer according to the provided pattern. CSV escaping (according to
993 RFC4180) is applied if required.
995 @var{segment_start_time} and @var{segment_end_time} specify
996 the segment start and end time expressed in seconds.
998 A list file with the suffix @code{".csv"} or @code{".ext"} will
999 auto-select this format.
1001 @samp{ext} is deprecated in favor or @samp{csv}.
1004 Generate an ffconcat file for the created segments. The resulting file
1005 can be read using the FFmpeg @ref{concat} demuxer.
1007 A list file with the suffix @code{".ffcat"} or @code{".ffconcat"} will
1008 auto-select this format.
1011 Generate an extended M3U8 file, version 3, compliant with
1012 @url{http://tools.ietf.org/id/draft-pantos-http-live-streaming}.
1014 A list file with the suffix @code{".m3u8"} will auto-select this format.
1017 If not specified the type is guessed from the list file name suffix.
1019 @item segment_time @var{time}
1020 Set segment duration to @var{time}, the value must be a duration
1021 specification. Default value is "2". See also the
1022 @option{segment_times} option.
1024 Note that splitting may not be accurate, unless you force the
1025 reference stream key-frames at the given time. See the introductory
1026 notice and the examples below.
1028 @item segment_atclocktime @var{1|0}
1029 If set to "1" split at regular clock time intervals starting from 00:00
1030 o'clock. The @var{time} value specified in @option{segment_time} is
1031 used for setting the length of the splitting interval.
1033 For example with @option{segment_time} set to "900" this makes it possible
1034 to create files at 12:00 o'clock, 12:15, 12:30, etc.
1036 Default value is "0".
1038 @item segment_time_delta @var{delta}
1039 Specify the accuracy time when selecting the start time for a
1040 segment, expressed as a duration specification. Default value is "0".
1042 When delta is specified a key-frame will start a new segment if its
1043 PTS satisfies the relation:
1045 PTS >= start_time - time_delta
1048 This option is useful when splitting video content, which is always
1049 split at GOP boundaries, in case a key frame is found just before the
1050 specified split time.
1052 In particular may be used in combination with the @file{ffmpeg} option
1053 @var{force_key_frames}. The key frame times specified by
1054 @var{force_key_frames} may not be set accurately because of rounding
1055 issues, with the consequence that a key frame time may result set just
1056 before the specified time. For constant frame rate videos a value of
1057 1/(2*@var{frame_rate}) should address the worst case mismatch between
1058 the specified time and the time set by @var{force_key_frames}.
1060 @item segment_times @var{times}
1061 Specify a list of split points. @var{times} contains a list of comma
1062 separated duration specifications, in increasing order. See also
1063 the @option{segment_time} option.
1065 @item segment_frames @var{frames}
1066 Specify a list of split video frame numbers. @var{frames} contains a
1067 list of comma separated integer numbers, in increasing order.
1069 This option specifies to start a new segment whenever a reference
1070 stream key frame is found and the sequential number (starting from 0)
1071 of the frame is greater or equal to the next value in the list.
1073 @item segment_wrap @var{limit}
1074 Wrap around segment index once it reaches @var{limit}.
1076 @item segment_start_number @var{number}
1077 Set the sequence number of the first segment. Defaults to @code{0}.
1079 @item strftime @var{1|0}
1080 Use the @code{strftime} function to define the name of the new
1081 segments to write. If this is selected, the output segment name must
1082 contain a @code{strftime} function template. Default value is
1085 @item break_non_keyframes @var{1|0}
1086 If enabled, allow segments to start on frames other than keyframes. This
1087 improves behavior on some players when the time between keyframes is
1088 inconsistent, but may make things worse on others, and can cause some oddities
1089 during seeking. Defaults to @code{0}.
1091 @item reset_timestamps @var{1|0}
1092 Reset timestamps at the begin of each segment, so that each segment
1093 will start with near-zero timestamps. It is meant to ease the playback
1094 of the generated segments. May not work with some combinations of
1095 muxers/codecs. It is set to @code{0} by default.
1097 @item initial_offset @var{offset}
1098 Specify timestamp offset to apply to the output packet timestamps. The
1099 argument must be a time duration specification, and defaults to 0.
1102 @subsection Examples
1106 Remux the content of file @file{in.mkv} to a list of segments
1107 @file{out-000.nut}, @file{out-001.nut}, etc., and write the list of
1108 generated segments to @file{out.list}:
1110 ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.list out%03d.nut
1114 Segment input and set output format options for the output segments:
1116 ffmpeg -i in.mkv -f segment -segment_time 10 -segment_format_options movflags=+faststart out%03d.mp4
1120 Segment the input file according to the split points specified by the
1121 @var{segment_times} option:
1123 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
1127 Use the @command{ffmpeg} @option{force_key_frames}
1128 option to force key frames in the input at the specified location, together
1129 with the segment option @option{segment_time_delta} to account for
1130 possible roundings operated when setting key frame times.
1132 ffmpeg -i in.mkv -force_key_frames 1,2,3,5,8,13,21 -codec:v mpeg4 -codec:a pcm_s16le -map 0 \
1133 -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 -segment_time_delta 0.05 out%03d.nut
1135 In order to force key frames on the input file, transcoding is
1139 Segment the input file by splitting the input file according to the
1140 frame numbers sequence specified with the @option{segment_frames} option:
1142 ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_frames 100,200,300,500,800 out%03d.nut
1146 Convert the @file{in.mkv} to TS segments using the @code{libx264}
1147 and @code{libfaac} encoders:
1149 ffmpeg -i in.mkv -map 0 -codec:v libx264 -codec:a libfaac -f ssegment -segment_list out.list out%03d.ts
1153 Segment the input file, and create an M3U8 live playlist (can be used
1154 as live HLS source):
1156 ffmpeg -re -i in.mkv -codec copy -map 0 -f segment -segment_list playlist.m3u8 \
1157 -segment_list_flags +live -segment_time 10 out%03d.mkv
1161 @section smoothstreaming
1163 Smooth Streaming muxer generates a set of files (Manifest, chunks) suitable for serving with conventional web server.
1167 Specify the number of fragments kept in the manifest. Default 0 (keep all).
1169 @item extra_window_size
1170 Specify the number of fragments kept outside of the manifest before removing from disk. Default 5.
1172 @item lookahead_count
1173 Specify the number of lookahead fragments. Default 2.
1175 @item min_frag_duration
1176 Specify the minimum fragment duration (in microseconds). Default 5000000.
1178 @item remove_at_exit
1179 Specify whether to remove all fragments when finished. Default 0 (do not remove).
1185 The tee muxer can be used to write the same data to several files or any
1186 other kind of muxer. It can be used, for example, to both stream a video to
1187 the network and save it to disk at the same time.
1189 It is different from specifying several outputs to the @command{ffmpeg}
1190 command-line tool because the audio and video data will be encoded only once
1191 with the tee muxer; encoding can be a very expensive process. It is not
1192 useful when using the libavformat API directly because it is then possible
1193 to feed the same packets to several muxers directly.
1195 The slave outputs are specified in the file name given to the muxer,
1196 separated by '|'. If any of the slave name contains the '|' separator,
1197 leading or trailing spaces or any special character, it must be
1198 escaped (see @ref{quoting_and_escaping,,the "Quoting and escaping"
1199 section in the ffmpeg-utils(1) manual,ffmpeg-utils}).
1201 Muxer options can be specified for each slave by prepending them as a list of
1202 @var{key}=@var{value} pairs separated by ':', between square brackets. If
1203 the options values contain a special character or the ':' separator, they
1204 must be escaped; note that this is a second level escaping.
1206 The following special options are also recognized:
1209 Specify the format name. Useful if it cannot be guessed from the
1212 @item bsfs[/@var{spec}]
1213 Specify a list of bitstream filters to apply to the specified
1216 It is possible to specify to which streams a given bitstream filter
1217 applies, by appending a stream specifier to the option separated by
1218 @code{/}. @var{spec} must be a stream specifier (see @ref{Format
1219 stream specifiers}). If the stream specifier is not specified, the
1220 bitstream filters will be applied to all streams in the output.
1222 Several bitstream filters can be specified, separated by ",".
1225 Select the streams that should be mapped to the slave output,
1226 specified by a stream specifier. If not specified, this defaults to
1227 all the input streams.
1230 @subsection Examples
1234 Encode something and both archive it in a WebM file and stream it
1235 as MPEG-TS over UDP (the streams need to be explicitly mapped):
1237 ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
1238 "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
1242 Use @command{ffmpeg} to encode the input, and send the output
1243 to three different destinations. The @code{dump_extra} bitstream
1244 filter is used to add extradata information to all the output video
1245 keyframes packets, as requested by the MPEG-TS format. The select
1246 option is applied to @file{out.aac} in order to make it contain only
1249 ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac -strict experimental
1250 -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac"
1254 As below, but select only stream @code{a:1} for the audio output. Note
1255 that a second level escaping must be performed, as ":" is a special
1256 character used to separate options.
1258 ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac -strict experimental
1259 -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=\'a:1\']out.aac"
1263 Note: some codecs may need different options depending on the output format;
1264 the auto-detection of this can not work with the tee muxer. The main example
1265 is the @option{global_header} flag.
1267 @section webm_dash_manifest
1269 WebM DASH Manifest muxer.
1271 This muxer implements the WebM DASH Manifest specification to generate the DASH
1272 manifest XML. It also supports manifest generation for DASH live streams.
1274 For more information see:
1278 WebM DASH Specification: @url{https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification}
1280 ISO DASH Specification: @url{http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip}
1285 This muxer supports the following options:
1288 @item adaptation_sets
1289 This option has the following syntax: "id=x,streams=a,b,c id=y,streams=d,e" where x and y are the
1290 unique identifiers of the adaptation sets and a,b,c,d and e are the indices of the corresponding
1291 audio and video streams. Any number of adaptation sets can be added using this option.
1294 Set this to 1 to create a live stream DASH Manifest. Default: 0.
1296 @item chunk_start_index
1297 Start index of the first chunk. This will go in the @samp{startNumber} attribute
1298 of the @samp{SegmentTemplate} element in the manifest. Default: 0.
1300 @item chunk_duration_ms
1301 Duration of each chunk in milliseconds. This will go in the @samp{duration}
1302 attribute of the @samp{SegmentTemplate} element in the manifest. Default: 1000.
1304 @item utc_timing_url
1305 URL of the page that will return the UTC timestamp in ISO format. This will go
1306 in the @samp{value} attribute of the @samp{UTCTiming} element in the manifest.
1309 @item time_shift_buffer_depth
1310 Smallest time (in seconds) shifting buffer for which any Representation is
1311 guaranteed to be available. This will go in the @samp{timeShiftBufferDepth}
1312 attribute of the @samp{MPD} element. Default: 60.
1314 @item minimum_update_period
1315 Minimum update period (in seconds) of the manifest. This will go in the
1316 @samp{minimumUpdatePeriod} attribute of the @samp{MPD} element. Default: 0.
1322 ffmpeg -f webm_dash_manifest -i video1.webm \
1323 -f webm_dash_manifest -i video2.webm \
1324 -f webm_dash_manifest -i audio1.webm \
1325 -f webm_dash_manifest -i audio2.webm \
1326 -map 0 -map 1 -map 2 -map 3 \
1328 -f webm_dash_manifest \
1329 -adaptation_sets "id=0,streams=0,1 id=1,streams=2,3" \
1335 WebM Live Chunk Muxer.
1337 This muxer writes out WebM headers and chunks as separate files which can be
1338 consumed by clients that support WebM Live streams via DASH.
1342 This muxer supports the following options:
1345 @item chunk_start_index
1346 Index of the first chunk (defaults to 0).
1349 Filename of the header where the initialization data will be written.
1351 @item audio_chunk_duration
1352 Duration of each audio chunk in milliseconds (defaults to 5000).
1357 ffmpeg -f v4l2 -i /dev/video0 \
1361 -s 640x360 -keyint_min 30 -g 30 \
1363 -header webm_live_video_360.hdr \
1364 -chunk_start_index 1 \
1365 webm_live_video_360_%d.chk \
1370 -header webm_live_audio_128.hdr \
1371 -chunk_start_index 1 \
1372 -audio_chunk_duration 1000 \
1373 webm_live_audio_128_%d.chk