Muxers
******

Muxers are configured elements in FFmpeg which allow writing multimedia streams to a particular type of file.

When you configure your FFmpeg build, all the supported muxers are enabled by default. You can list all available muxers using the configure option --list-muxers.

You can disable all the muxers with the configure option --disable-muxers and selectively enable / disable single muxers with the options --enable-muxer=MUXER / --disable-muxer=MUXER.

The option -muxers of the ff* tools will display the list of enabled muxers. Use -formats to view a combined list of enabled demuxers and muxers.

A description of some of the currently available muxers follows.

Raw muxers
==========

This section covers raw muxers. They accept a single stream matching the designated codec. They do not store timestamps or metadata. The recognized extension is the same as the muxer name unless indicated otherwise.

It comprises the following muxers. The media type and the eventual extensions used to automatically selects the muxer from the output extensions are also shown.

ac3 audio
     Dolby Digital, also known as AC-3.

adx audio
     CRI Middleware ADX audio.

     This muxer will write out the total sample count near the start of the first packet when the output is seekable and the count can be stored in 32 bits.

aptx audio
     aptX (Audio Processing Technology for Bluetooth)

aptx_hd audio (aptxdh)
     aptX HD (Audio Processing Technology for Bluetooth) audio

avs2 video (avs, avs2)
     AVS2-P2 (Audio Video Standard - Second generation - Part 2) / IEEE 1857.4 video

avs3 video (avs3)
     AVS3-P2 (Audio Video Standard - Third generation - Part 2) / IEEE 1857.10 video

cavsvideo video (cavs)
     Chinese AVS (Audio Video Standard - First generation)

codec2raw audio
     Codec 2 audio.

     No extension is registered so format name has to be supplied e.g. with the ffmpeg CLI tool -f codec2raw.

data any
     Generic data muxer.

     This muxer accepts a single stream with any codec of any type. The input stream has to be selected using the -map option with the ffmpeg CLI tool.

     No extension is registered so format name has to be supplied e.g. with the ffmpeg CLI tool -f data.

dfpwm audio (dfpwm)
     Raw DFPWM1a (Dynamic Filter Pulse With Modulation) audio muxer.

dirac video (drc, vc2)
     BBC Dirac video.

     The Dirac Pro codec is a subset and is standardized as SMPTE VC-2.

dnxhd video (dnxhd, dnxhr)
     Avid DNxHD video.

     It is standardized as SMPTE VC-3. Accepts DNxHR streams.

dts audio
     DTS Coherent Acoustics (DCA) audio

eac3 audio
     Dolby Digital Plus, also known as Enhanced AC-3

evc video (evc)
     MPEG-5 Essential Video Coding (EVC) / EVC / MPEG-5 Part 1 EVC video

g722 audio
     ITU-T G.722 audio

g723_1 audio (tco, rco)
     ITU-T G.723.1 audio

g726 audio
     ITU-T G.726 big-endian ("left-justified") audio.

     No extension is registered so format name has to be supplied e.g. with the ffmpeg CLI tool -f g726.

g726le audio
     ITU-T G.726 little-endian ("right-justified") audio.

     No extension is registered so format name has to be supplied e.g. with the ffmpeg CLI tool -f g726le.

gsm audio
     Global System for Mobile Communications audio

h261 video
     ITU-T H.261 video

h263 video
     ITU-T H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2 video

h264 video (h264, 264)
     ITU-T H.264 / MPEG-4 Part 10 AVC video. Bitstream shall be converted to Annex B syntax if it's in length-prefixed mode.

hevc video (hevc, h265, 265)
     ITU-T H.265 / MPEG-H Part 2 HEVC video. Bitstream shall be converted to Annex B syntax if it's in length-prefixed mode.

m4v video
     MPEG-4 Part 2 video

mjpeg video (mjpg, mjpeg)
     Motion JPEG video

mlp audio
     Meridian Lossless Packing, also known as Packed PCM

mp2 audio (mp2, m2a, mpa)
     MPEG-1 Audio Layer II audio

mpeg1video video (mpg, mpeg, m1v)
     MPEG-1 Part 2 video.

mpeg2video video (m2v)
     ITU-T H.262 / MPEG-2 Part 2 video

obu video
     AV1 low overhead Open Bitstream Units muxer.

     Temporal delimiter OBUs will be inserted in all temporal units of the stream.

rawvideo video (yuv, rgb)
     Raw uncompressed video.

sbc audio (sbc, msbc)
     Bluetooth SIG low-complexity subband codec audio

truehd audio (thd)
     Dolby TrueHD audio

vc1 video
     SMPTE 421M / VC-1 video

Examples
--------

  * Store raw video frames with the rawvideo muxer using ffmpeg:

          ffmpeg -f lavfi -i testsrc -t 10 -s hd1080p testsrc.yuv

     Since the rawvideo muxer do not store the information related to size and format, this information must be provided when demuxing the file:

          ffplay -video_size 1920x1080 -pixel_format rgb24 -f rawvideo testsrc.rgb

Raw PCM muxers
==============

This section covers raw PCM (Pulse-Code Modulation) audio muxers.

They accept a single stream matching the designated codec. They do not store timestamps or metadata. The recognized extension is the same as the muxer name.

It comprises the following muxers. The optional additional extension used to automatically select the muxer from the output extension is also shown in parentheses.

alaw (al)
     PCM A-law

f32be
     PCM 32-bit floating-point big-endian

f32le
     PCM 32-bit floating-point little-endian

f64be
     PCM 64-bit floating-point big-endian

f64le
     PCM 64-bit floating-point little-endian

mulaw (ul)
     PCM mu-law

s16be
     PCM signed 16-bit big-endian

s16le
     PCM signed 16-bit little-endian

s24be
     PCM signed 24-bit big-endian

s24le
     PCM signed 24-bit little-endian

s32be
     PCM signed 32-bit big-endian

s32le
     PCM signed 32-bit little-endian

s8 (sb)
     PCM signed 8-bit

u16be
     PCM unsigned 16-bit big-endian

u16le
     PCM unsigned 16-bit little-endian

u24be
     PCM unsigned 24-bit big-endian

u24le
     PCM unsigned 24-bit little-endian

u32be
     PCM unsigned 32-bit big-endian

u32le
     PCM unsigned 32-bit little-endian

u8 (ub)
     PCM unsigned 8-bit

vidc
     PCM Archimedes VIDC

MPEG-1/MPEG-2 program stream muxers
===================================

This section covers formats belonging to the MPEG-1 and MPEG-2 Systems family.

The MPEG-1 Systems format (also known as ISO/IEEC 11172-1 or MPEG-1 program stream) has been adopted for the format of media track stored in VCD (Video Compact Disc).

The MPEG-2 Systems standard (also known as ISO/IEEC 13818-1) covers two containers formats, one known as transport stream and one known as program stream; only the latter is covered here.

The MPEG-2 program stream format (also known as VOB due to the corresponding file extension) is an extension of MPEG-1 program stream: in addition to support different codecs for the audio and video streams, it also stores subtitles and navigation metadata. MPEG-2 program stream has been adopted for storing media streams in SVCD and DVD storage devices.

This section comprises the following muxers.

mpeg (mpg,mpeg)
     MPEG-1 Systems / MPEG-1 program stream muxer.

vcd
     MPEG-1 Systems / MPEG-1 program stream (VCD) muxer.

     This muxer can be used to generate tracks in the format accepted by the VCD (Video Compact Disc) storage devices.

     It is the same as the mpeg muxer with a few differences.

vob
     MPEG-2 program stream (VOB) muxer.

dvd
     MPEG-2 program stream (DVD VOB) muxer.

     This muxer can be used to generate tracks in the format accepted by the DVD (Digital Versatile Disc) storage devices.

     This is the same as the vob muxer with a few differences.

svcd (vob)
     MPEG-2 program stream (SVCD VOB) muxer.

     This muxer can be used to generate tracks in the format accepted by the SVCD (Super Video Compact Disc) storage devices.

     This is the same as the vob muxer with a few differences.

Options
-------

muxrate RATE
     Set user-defined mux rate expressed as a number of bits/s. If not specified the automatically computed mux rate is employed. Default value is 0.

preload DELAY
     Set initial demux-decode delay in microseconds. Default value is 500000.

MOV/MPEG-4/ISOMBFF muxers
=========================

This section covers formats belonging to the QuickTime / MOV family, including the MPEG-4 Part 14 format and ISO base media file format (ISOBMFF). These formats share a common structure based on the ISO base media file format (ISOBMFF).

The MOV format was originally developed for use with Apple QuickTime. It was later used as the basis for the MPEG-4 Part 1 (later Part 14) format, also known as ISO/IEC 14496-1. That format was then generalized into ISOBMFF, also named MPEG-4 Part 12 format, ISO/IEC 14496-12, or ISO/IEC 15444-12.

It comprises the following muxers.

3gp
     Third Generation Partnership Project (3GPP) format for 3G UMTS multimedia services

3g2
     Third Generation Partnership Project 2 (3GP2 or 3GPP2) format for 3G CDMA2000 multimedia services, similar to 3gp with extensions and limitations

f4v
     Adobe Flash Video format

ipod
     MPEG-4 audio file format, as MOV/MP4 but limited to contain only audio streams, typically played with the Apple ipod device

ismv
     Microsoft IIS (Internet Information Services) Smooth Streaming Audio/Video (ISMV or ISMA) format. This is based on MPEG-4 Part 14 format with a few incompatible variants, used to stream media files for the Microsoft IIS server.

mov
     QuickTime player format identified by the .mov extension

mp4
     MP4 or MPEG-4 Part 14 format

psp
     PlayStation Portable MP4/MPEG-4 Part 14 format variant. This is based on MPEG-4 Part 14 format with a few incompatible variants, used to play files on PlayStation devices.

Fragmentation
-------------

The mov, mp4, and ismv muxers support fragmentation. Normally, a MOV/MP4 file has all the metadata about all packets stored in one location.

This data is usually written at the end of the file, but it can be moved to the start for better playback by adding +faststart to the -movflags, or using the qt-faststart tool).

A fragmented file consists of a number of fragments, where packets and metadata about these packets are stored together. Writing a fragmented file has the advantage that the file is decodable even if the writing is interrupted (while a normal MOV/MP4 is undecodable if it is not properly finished), and it requires less memory when writing very long files (since writing normal MOV/MP4 files stores info about every single packet in memory until the file is closed). The downside is that it is less compatible with other applications.

Fragmentation is enabled by setting one of the options that define how to cut the file into fragments:

frag_duration

frag_size

min_frag_duration

movflags +frag_keyframe

movflags +frag_custom

If more than one condition is specified, fragments are cut when one of the specified conditions is fulfilled. The exception to this is the option min_frag_duration, which has to be fulfilled for any of the other conditions to apply.

Options
-------

brand BRAND_STRING
     Override major brand.

empty_hdlr_name BOOL
     Enable to skip writing the name inside a hdlr box. Default is false.

encryption_key KEY
     set the media encryption key in hexadecimal format

encryption_kid KID
     set the media encryption key identifier in hexadecimal format

encryption_scheme SCHEME
     configure the encryption scheme, allowed values are none, and cenc-aes-ctr

frag_duration DURATION
     Create fragments that are DURATION microseconds long.

frag_interleave  NUMBER
     Interleave samples within fragments (max number of consecutive samples, lower is tighter interleaving, but with more overhead. It is set to 0 by default.

frag_size SIZE
     create fragments that contain up to SIZE bytes of payload data

iods_audio_profile PROFILE
     specify iods number for the audio profile atom (from -1 to 255), default is -1

iods_video_profile PROFILE
     specify iods number for the video profile atom (from -1 to 255), default is -1

ism_lookahead NUM_ENTRIES
     specify number of lookahead entries for ISM files (from 0 to 255), default is 0

min_frag_duration DURATION
     do not create fragments that are shorter than DURATION microseconds long

moov_size BYTES
     Reserves space for the moov atom at the beginning of the file instead of placing the moov atom at the end. If the space reserved is insufficient, muxing will fail.

mov_gamma GAMMA
     specify gamma value for gama atom (as a decimal number from 0 to 10), default is 0.0, must be set together with + movflags

movflags FLAGS
     Set various muxing switches. The following flags can be used:

     cmaf
          write CMAF (Common Media Application Format) compatible fragmented MP4 output

     dash
          write DASH (Dynamic Adaptive Streaming over HTTP) compatible fragmented MP4 output

     default_base_moof
          Similarly to the omit_tfhd_offset flag, this flag avoids writing the absolute base_data_offset field in tfhd atoms, but does so by using the new default-base-is-moof flag instead. This flag is new from 14496-12:2012. This may make the fragments easier to parse in certain circumstances (avoiding basing track fragment location calculations on the implicit end of the previous track fragment).

     delay_moov
          delay writing the initial moov until the first fragment is cut, or until the first fragment flush

     disable_chpl
          Disable Nero chapter markers (chpl atom). Normally, both Nero chapters and a QuickTime chapter track are written to the file. With this option set, only the QuickTime chapter track will be written. Nero chapters can cause failures when the file is reprocessed with certain tagging programs, like mp3Tag 2.61a and iTunes 11.3, most likely other versions are affected as well.

     faststart
          Run a second pass moving the index (moov atom) to the beginning of the file. This operation can take a while, and will not work in various situations such as fragmented output, thus it is not enabled by default.

     frag_custom
          Allow the caller to manually choose when to cut fragments, by calling av_write_frame(ctx, NULL) to write a fragment with the packets written so far. (This is only useful with other applications integrating libavformat, not from ffmpeg.)

     frag_discont
          signal that the next fragment is discontinuous from earlier ones

     frag_every_frame
          fragment at every frame

     frag_keyframe
          start a new fragment at each video keyframe

     global_sidx
          write a global sidx index at the start of the file

     isml
          create a live smooth streaming feed (for pushing to a publishing point)

     negative_cts_offsets
          Enables utilization of version 1 of the CTTS box, in which the CTS offsets can be negative. This enables the initial sample to have DTS/CTS of zero, and reduces the need for edit lists for some cases such as video tracks with B-frames. Additionally, eases conformance with the DASH-IF interoperability guidelines.

          This option is implicitly set when writing ismv (Smooth Streaming) files.

     omit_tfhd_offset
          Do not write any absolute base_data_offset in tfhd atoms. This avoids tying fragments to absolute byte positions in the file/streams.

     prefer_icc
          If writing colr atom prioritise usage of ICC profile if it exists in stream packet side data.

     rtphint
          add RTP hinting tracks to the output file

     separate_moof
          Write a separate moof (movie fragment) atom for each track. Normally, packets for all tracks are written in a moof atom (which is slightly more efficient), but with this option set, the muxer writes one moof/mdat pair for each track, making it easier to separate tracks.

     skip_sidx
          Skip writing of sidx atom. When bitrate overhead due to sidx atom is high, this option could be used for cases where sidx atom is not mandatory. When the global_sidx flag is enabled, this option is ignored.

     skip_trailer
          skip writing the mfra/tfra/mfro trailer for fragmented files

     use_metadata_tags
          use mdta atom for metadata

     write_colr
          write colr atom even if the color info is unspecified. This flag is experimental, may be renamed or changed, do not use from scripts.

     write_gama
          write deprecated gama atom

     hybrid_fragmented
          For recoverability - write the output file as a fragmented file. This allows the intermediate file to be read while being written (in particular, if the writing process is aborted uncleanly). When writing is finished, the file is converted to a regular, non-fragmented file, which is more compatible and allows easier and quicker seeking.

          If writing is aborted, the intermediate file can manually be remuxed to get a regular, non-fragmented file of what had been written into the unfinished file.

movie_timescale SCALE
     Set the timescale written in the movie header box (mvhd). Range is 1 to INT_MAX. Default is 1000.

rtpflags FLAGS
     Add RTP hinting tracks to the output file.

     The following flags can be used:

     h264_mode0
          use mode 0 for H.264 in RTP

     latm
          use MP4A-LATM packetization instead of MPEG4-GENERIC for AAC

     rfc2190
          use RFC 2190 packetization instead of RFC 4629 for H.263

     send_bye
          send RTCP BYE packets when finishing

     skip_rtcp
          do not send RTCP sender reports

skip_iods BOOL
     skip writing iods atom (default value is true)

use_editlist BOOL
     use edit list (default value is auto)

use_stream_ids_as_track_ids BOOL
     use stream ids as track ids (default value is false)

video_track_timescale SCALE
     Set the timescale used for video tracks. Range is 0 to INT_MAX. If set to 0, the timescale is automatically set based on the native stream time base. Default is 0.

write_btrt BOOL
     Force or disable writing bitrate box inside stsd box of a track. The box contains decoding buffer size (in bytes), maximum bitrate and average bitrate for the track. The box will be skipped if none of these values can be computed.  Default is -1 or auto, which will write the box only in MP4 mode.

write_prft OPTION
     Write producer time reference box (PRFT) with a specified time source for the NTP field in the PRFT box. Set value as wallclock to specify timesource as wallclock time and pts to specify timesource as input packets' PTS values.

write_tmcd BOOL
     Specify on to force writing a timecode track, off to disable it and auto to write a timecode track only for mov and mp4 output (default).

     Setting value to pts is applicable only for a live encoding use case, where PTS values are set as as wallclock time at the source. For example, an encoding use case with decklink capture source where video_pts and audio_pts are set to abs_wallclock.

Examples
--------

  * Push Smooth Streaming content in real time to a publishing point on IIS with the ismv muxer using ffmpeg:

          ffmpeg -re <NORMAL INPUT/TRANSCODING OPTIONS> -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1)

a64
===

A64 Commodore 64 video muxer.

This muxer accepts a single a64_multi or a64_multi5 codec video stream.

ac4
===

Raw AC-4 audio muxer.

This muxer accepts a single ac4 audio stream.

Options
-------

write_crc BOOL
     when enabled, write a CRC checksum for each packet to the output, default is false

adts
====

Audio Data Transport Stream muxer.

It accepts a single AAC stream.

Options
-------

write_id3v2 BOOL
     Enable to write ID3v2.4 tags at the start of the stream. Default is disabled.

write_apetag BOOL
     Enable to write APE tags at the end of the stream. Default is disabled.

write_mpeg2 BOOL
     Enable to set MPEG version bit in the ADTS frame header to 1 which indicates MPEG-2. Default is 0, which indicates MPEG-4.

aea
===

MD STUDIO audio muxer.

This muxer accepts a single ATRAC1 audio stream with either one or two channels and a sample rate of 44100Hz.

As AEA supports storing the track title, this muxer will also write the title from stream's metadata to the container.

aiff
====

Audio Interchange File Format muxer.

Options
-------

write_id3v2 BOOL
     Enable ID3v2 tags writing when set to 1. Default is 0 (disabled).

id3v2_version BOOL
     Select ID3v2 version to write. Currently only version 3 and 4 (aka. ID3v2.3 and ID3v2.4) are supported. The default is version 4.

alp
===

High Voltage Software's Lego Racers game audio muxer.

It accepts a single ADPCM_IMA_ALP stream with no more than 2 channels and a sample rate not greater than 44100 Hz.

Extensions: tun, pcm

Options
-------

type TYPE
     Set file type.

     TYPE accepts the following values:

     tun
          Set file type as music. Must have a sample rate of 22050 Hz.

     pcm
          Set file type as sfx.

     auto
          Set file type as per output file extension. .pcm results in type pcm else type tun is set. (DEFAULT)

amr
===

3GPP AMR (Adaptive Multi-Rate) audio muxer.

It accepts a single audio stream containing an AMR NB stream.

amv
===

AMV (Actions Media Video) format muxer.

apm
===

Ubisoft Rayman 2 APM audio muxer.

It accepts a single ADPCM IMA APM audio stream.

apng
====

Animated Portable Network Graphics muxer.

It accepts a single APNG video stream.

Options
-------

final_delay DELAY
     Force a delay expressed in seconds after the last frame of each repetition. Default value is 0.0.

plays REPETITIONS
     specify how many times to play the content, 0 causes an infinite loop, with 1 there is no loop

Examples
--------

  * Use ffmpeg to generate an APNG output with 2 repetitions, and with a delay of half a second after the first repetition:

          ffmpeg -i INPUT -final_delay 0.5 -plays 2 out.apng

argo_asf
========

Argonaut Games ASF audio muxer.

It accepts a single ADPCM audio stream.

Options
-------

version_major VERSION
     override file major version, specified as an integer, default value is 2

version_minor VERSION
     override file minor version, specified as an integer, default value is 1

name NAME
     Embed file name into file, if not specified use the output file name. The name is truncated to 8 characters.

argo_cvg
========

Argonaut Games CVG audio muxer.

It accepts a single one-channel ADPCM 22050Hz audio stream.

The loop and reverb options set the corresponding flags in the header which can be later retrieved to process the audio stream accordingly.

Options
-------

skip_rate_check BOOL
     skip sample rate check (default is false)

loop BOOL
     set loop flag (default is false)

reverb BOOLEAN
     set reverb flag (default is true)

asf, asf_stream
===============

Advanced / Active Systems (or Streaming) Format audio muxer.

The asf_stream variant should be selected for streaming.

Note that Windows Media Audio (wma) and Windows Media Video (wmv) use this muxer too.

Options
-------

packet_size SIZE
     Set the muxer packet size as a number of bytes. By tuning this setting you may reduce data fragmentation or muxer overhead depending on your source. Default value is 3200, minimum is 100, maximum is 64Ki.

ass
===

ASS/SSA (SubStation Alpha) subtitles muxer.

It accepts a single ASS subtitles stream.

Options
-------

ignore_readorder BOOL
     Write dialogue events immediately, even if they are out-of-order, default is false, otherwise they are cached until the expected time event is found.

ast
===

AST (Audio Stream) muxer.

This format is used to play audio on some Nintendo Wii games.

It accepts a single audio stream.

The loopstart and loopend options can be used to define a section of the file to loop for players honoring such options.

Options
-------

loopstart START
     Specify loop start position expressesd in milliseconds, from -1 to INT_MAX, in case -1 is set then no loop is specified (default -1) and the loopend value is ignored.

loopend END
     Specify loop end position expressed in milliseconds, from 0 to INT_MAX, default is 0, in case 0 is set it assumes the total stream duration.

au
==

SUN AU audio muxer.

It accepts a single audio stream.

avi
===

Audio Video Interleaved muxer.

AVI is a proprietary format developed by Microsoft, and later formally specified through the Open DML specification.

Because of differences in players implementations, it might be required to set some options to make sure that the generated output can be correctly played by the target player.

Options
-------

flipped_raw_rgb BOOL
     If set to true, store positive height for raw RGB bitmaps, which indicates bitmap is stored bottom-up. Note that this option does not flip the bitmap which has to be done manually beforehand, e.g. by using the vflip filter. Default is false and indicates bitmap is stored top down.

reserve_index_space SIZE
     Reserve the specified amount of bytes for the OpenDML master index of each stream within the file header. By default additional master indexes are embedded within the data packets if there is no space left in the first master index and are linked together as a chain of indexes. This index structure can cause problems for some use cases, e.g. third-party software strictly relying on the OpenDML index specification or when file seeking is slow. Reserving enough index space in the file header avoids these problems.

     The required index space depends on the output file size and should be about 16 bytes per gigabyte. When this option is omitted or set to zero the necessary index space is guessed.

     Default value is 0.

write_channel_mask BOOL
     Write the channel layout mask into the audio stream header.

     This option is enabled by default. Disabling the channel mask can be useful in specific scenarios, e.g. when merging multiple audio streams into one for compatibility with software that only supports a single audio stream in AVI (see the "amerge" section in the ffmpeg-filters manual (ffmpeg-filters)).

avif
====

AV1 (Alliance for Open Media Video codec 1) image format muxer.

This muxers stores images encoded using the AV1 codec.

It accepts one or two video streams. In case two video streams are provided, the second one shall contain a single plane storing the alpha mask.

In case more than one image is provided, the generated output is considered an animated AVIF and the number of loops can be specified with the loop option.

This is based on the specification by Alliance for Open Media at url https://aomediacodec.github.io/av1-avif.

Options
-------

loop COUNT
     number of times to loop an animated AVIF, 0 specify an infinite loop, default is 0

movie_timescale TIMESCALE
     Set the timescale written in the movie header box (mvhd). Range is 1 to INT_MAX. Default is 1000.

avm2
====

ShockWave Flash (SWF) / ActionScript Virtual Machine 2 (AVM2) format muxer.

It accepts one audio stream, one video stream, or both.

bit
===

G.729 (.bit) file format muxer.

It accepts a single G.729 audio stream.

caf
===

Apple CAF (Core Audio Format) muxer.

It accepts a single audio stream.

codec2
======

Codec2 audio audio muxer.

It accepts a single codec2 audio stream.

chromaprint
===========

Chromaprint fingerprinter muxers.

To enable compilation of this filter you need to configure FFmpeg with --enable-chromaprint.

This muxer feeds audio data to the Chromaprint library, which generates a fingerprint for the provided audio data. See: https://acoustid.org/chromaprint

It takes a single signed native-endian 16-bit raw audio stream of at most 2 channels.

Options
-------

algorithm VERSION
     Select version of algorithm to fingerprint with. Range is 0 to 4. Version 3 enables silence detection. Default is 1.

fp_format FORMAT
     Format to output the fingerprint as. Accepts the following options:

     base64
          Base64 compressed fingerprint (default)

     compressed
          Binary compressed fingerprint

     raw
          Binary raw fingerprint

silence_threshold THRESHOLD
     Threshold for detecting silence. Range is from -1 to 32767, where -1 disables silence detection. Silence detection can only be used with version 3 of the algorithm.

     Silence detection must be disabled for use with the AcoustID service. Default is -1.

crc
===

CRC (Cyclic Redundancy Check) muxer.

This muxer computes and prints the Adler-32 CRC of all the input audio and video frames. By default audio frames are converted to signed 16-bit raw audio and video frames to raw video before computing the CRC.

The output of the muxer consists of a single line of the form: CRC=0xCRC, where CRC is a hexadecimal number 0-padded to 8 digits containing the CRC for all the decoded input frames.

See also the framecrc muxer.

Examples
--------

  * Use ffmpeg to compute the CRC of the input, and store it in the file out.crc:

          ffmpeg -i INPUT -f crc out.crc

  * Use ffmpeg to print the CRC to stdout with the command:

          ffmpeg -i INPUT -f crc -

  * You can select the output format of each frame with ffmpeg by specifying the audio and video codec and format. For example, to compute the CRC of the input audio converted to PCM unsigned 8-bit and the input video converted to MPEG-2 video, use the command:

          ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc -

dash
====

Dynamic Adaptive Streaming over HTTP (DASH) muxer.

This muxer creates segments and manifest files according to the MPEG-DASH standard ISO/IEC 23009-1:2014 and following standard updates.

For more information see:

  * ISO DASH Specification: http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip

  * WebM DASH Specification: https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification

This muxer creates an MPD (Media Presentation Description) manifest file and segment files for each stream. Segment files are placed in the same directory of the MPD manifest file.

The segment filename might contain pre-defined identifiers used in the manifest SegmentTemplate section as defined in section 5.3.9.4.4 of the standard.

Available identifiers are $RepresentationID$, $Number$, $Bandwidth$, and $Time$. In addition to the standard identifiers, an ffmpeg-specific $ext$ identifier is also supported. When specified, ffmpeg will replace $ext$ in the file name with muxing format's extensions such as mp4, webm etc.

Options
-------

adaptation_sets ADAPTATION_SETS
     Assign streams to adaptation sets, specified in the MPD manifest AdaptationSets section.

     An adaptation set contains a set of one or more streams accessed as a single subset, e.g. corresponding streams encoded at different size selectable by the user depending on the available bandwidth, or to different audio streams with a different language.

     Each adaptation set is specified with the syntax:

          id=INDEX,streams=STREAMS

     where INDEX must be a numerical index, and STREAMS is a sequence of ,-separated stream indices. Multiple adaptation sets can be specified, separated by spaces.

     To map all video (or audio) streams to an adaptation set, v (or a) can be used as stream identifier instead of IDs.

     When no assignment is defined, this defaults to an adaptation set for each stream.

     The following optional fields can also be specified:

     descriptor
          Define the descriptor as defined by ISO/IEC 23009-1:2014/Amd.2:2015.

          For example:

               <SupplementalProperty schemeIdUri=\"urn:mpeg:dash:srd:2014\" value=\"0,0,0,1,1,2,2\"/>

          The descriptor string should be a self-closing XML tag.

     frag_duration
          Override the global fragment duration specified with the frag_duration option.

     frag_type
          Override the global fragment type specified with the frag_type option.

     seg_duration
          Override the global segment duration specified with the seg_duration option.

     trick_id
          Mark an adaptation set as containing streams meant to be used for Trick Mode for the referenced adaptation set.

     A few examples of possible values for the adaptation_sets option follow:

          id=0,seg_duration=2,frag_duration=1,frag_type=duration,streams=v id=1,seg_duration=2,frag_type=none,streams=a

          id=0,seg_duration=2,frag_type=none,streams=0 id=1,seg_duration=10,frag_type=none,trick_id=0,streams=1

dash_segment_type TYPE
     Set DASH segment files type.

     Possible values:

     auto
          The dash segment files format will be selected based on the stream codec. This is the default mode.

     mp4
          the dash segment files will be in ISOBMFF/MP4 format

     webm
          the dash segment files will be in WebM format

extra_window_size SIZE
     Set the maximum number of segments kept outside of the manifest before removing from disk.

format_options OPTIONS_LIST
     Set container format (mp4/webm) options using a :-separated list of key=value parameters. Values containing : special characters must be escaped.

frag_duration DURATION
     Set the length in seconds of fragments within segments, fractional value can also be set.

frag_type TYPE
     Set the type of interval for fragmentation.

     Possible values:

     auto
          set one fragment per segment

     every_frame
          fragment at every frame

     duration
          fragment at specific time intervals

     pframes
          fragment at keyframes and following P-Frame reordering (Video only, experimental)

global_sidx BOOL
     Write global SIDX atom. Applicable only for single file, mp4 output, non-streaming mode.

hls_master_name FILE_NAME
     HLS master playlist name. Default is master.m3u8.

hls_playlist BOOL
     Generate HLS playlist files. The master playlist is generated with filename specified by the hls_master_name option. One media playlist file is generated for each stream with filenames media_0.m3u8, media_1.m3u8, etc.

http_opts HTTP_OPTS
     Specify a list of :-separated key=value options to pass to the underlying HTTP protocol. Applicable only for HTTP output.

http_persistent BOOL
     Use persistent HTTP connections. Applicable only for HTTP output.

http_user_agent USER_AGENT
     Override User-Agent field in HTTP header. Applicable only for HTTP output.

ignore_io_errors BOOL
     Ignore IO errors during open and write. Useful for long-duration runs with network output. This is disabled by default.

index_correction BOOL
     Enable or disable segment index correction logic. Applicable only when use_template is enabled and use_timeline is disabled. This is disabled by default.

     When enabled, the logic monitors the flow of segment indexes. If a streams's segment index value is not at the expected real time position, then the logic corrects that index value.

     Typically this logic is needed in live streaming use cases. The network bandwidth fluctuations are common during long run streaming. Each fluctuation can cause the segment indexes fall behind the expected real time position.

init_seg_name INIT_NAME
     DASH-templated name to use for the initialization segment. Default is init-stream$RepresentationID$.$ext$. $ext$ is replaced with the file name extension specific for the segment format.

ldash BOOL
     Enable Low-latency Dash by constraining the presence and values of some elements. This is disabled by default.

lhls BOOL
     Enable Low-latency HLS (LHLS). Add #EXT-X-PREFETCH tag with current segment's URI. hls.js player folks are trying to standardize an open LHLS spec. The draft spec is available at https://github.com/video-dev/hlsjs-rfcs/blob/lhls-spec/proposals/0001-lhls.md.

     This option tries to comply with the above open spec. It enables streaming and hls_playlist options automatically. This is an experimental feature.

     Note: This is not Apple's version LHLS. See https://datatracker.ietf.org/doc/html/draft-pantos-hls-rfc8216bis

master_m3u8_publish_rate SEGMENT_INTERVALS_COUNT
     Publish master playlist repeatedly every after specified number of segment intervals.

max_playback_rate RATE
     Set the maximum playback rate indicated as appropriate for the purposes of automatically adjusting playback latency and buffer occupancy during normal playback by clients.

media_seg_name SEGMENT_NAME
     DASH-templated name to use 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.

method METHOD
     Use the given HTTP method to create output files. Generally set to PUT or POST.

min_playback_rate RATE
     Set the minimum playback rate indicated as appropriate for the purposes of automatically adjusting playback latency and buffer occupancy during normal playback by clients.

mpd_profile FLAGS
     Set one or more MPD manifest profiles.

     Possible values:

     dash
          MPEG-DASH ISO Base media file format live profile

     dvb_dash
          DVB-DASH profile

     Default value is dash.

remove_at_exit BOOL
     Enable or disable removal of all segments when finished. This is disabled by default.

seg_duration DURATION
     Set the segment length in seconds (fractional value can be set). The value is treated as average segment duration when the use_template option is enabled and the use_timeline option is disabled and as minimum segment duration for all the other use cases.

     Default value is 5.

single_file BOOL
     Enable or disable storing all segments in one file, accessed using byte ranges. This is disabled by default.

     The name of the single file can be specified with the single_file_name option, if not specified assume the basename of the manifest file with the output format extension.

single_file_name FILE_NAME
     DASH-templated name to use for the manifest baseURL element. Imply that the single_file option is set to TRUE. In the template, $ext$ is replaced with the file name extension specific for the segment format.

streaming BOOL
     Enable or disable chunk streaming mode of output. In chunk streaming mode, each frame will be a moof fragment which forms a chunk. This is disabled by default.

target_latency TARGET_LATENCY
     Set an intended target latency in seconds for serving (fractional value can be set). Applicable only when the streaming and write_prft options are enabled. This is an informative fields clients can use to measure the latency of the service.

timeout TIMEOUT
     Set timeout for socket I/O operations expressed in seconds (fractional value can be set). Applicable only for HTTP output.

update_period PERIOD
     Set the MPD update period, for dynamic content. The unit is second. If set to 0, the period is automatically computed.

     Default value is 0.

use_template BOOL
     Enable or disable use of SegmentTemplate instead of SegmentList in the manifest. This is enabled by default.

use_timeline BOOL
     Enable or disable use of SegmentTimeline within the SegmentTemplate manifest section. This is enabled by default.

utc_timing_url URL
     URL of the page that will return the UTC timestamp in ISO format, for example https://time.akamai.com/?iso

window_size SIZE
     Set the maximum number of segments kept in the manifest, discard the oldest one. This is useful for live streaming.

     If the value is 0, all segments are kept in the manifest. Default value is 0.

write_prft WRITE_PRFT
     Write Producer Reference Time elements on supported streams. This also enables writing prft boxes in the underlying muxer. Applicable only when the UTC_URL option is enabled. It is set to AUTO by default, in which case the muxer will attempt to enable it only in modes that require it.

Example
-------

Generate a DASH output reading from an input source in realtime using ffmpeg.

Two multimedia streams are generated from the input file, both containing a video stream encoded through libx264, and an audio stream encoded with libfdk_aac. The first multimedia stream contains video with a bitrate of 800k and audio at the default rate, the second with video scaled to 320x170 pixels at 300k and audio resampled at 22005 Hz.

The window_size option keeps only the latest 5 segments with the default duration of 5 seconds.

     ffmpeg -re -i <input> -map 0 -map 0 -c:a libfdk_aac -c:v libx264 \
     -b:v:0 800k -profile:v:0 main \
     -b:v:1 300k -s:v:1 320x170 -profile:v:1 baseline -ar:a:1 22050 \
     -bf 1 -keyint_min 120 -g 120 -sc_threshold 0 -b_strategy 0 \
     -use_timeline 1 -use_template 1 -window_size 5 \
     -adaptation_sets "id=0,streams=v id=1,streams=a" \
     -f dash /path/to/out.mpd

daud
====

D-Cinema audio muxer.

It accepts a single 6-channels audio stream resampled at 96000 Hz encoded with the pcm_24daud codec.

Example
-------

Use ffmpeg to mux input audio to a 5.1 channel layout resampled at 96000Hz:

     ffmpeg -i INPUT -af aresample=96000,pan=5.1 slow.302

For ffmpeg versions before 7.0 you might have to use the asetnsamples filter to limit the muxed packet size, because this format does not support muxing packets larger than 65535 bytes (3640 samples). For newer ffmpeg versions audio is automatically packetized to 36000 byte (2000 sample) packets.

dv
==

DV (Digital Video) muxer.

It accepts exactly one dvvideo video stream and at most two pcm_s16 audio streams. More constraints are defined by the property of the video, which must correspond to a DV video supported profile, and on the framerate.

Example
-------

Use ffmpeg to convert the input:

     ffmpeg -i INPUT -s:v 720x480 -pix_fmt yuv411p -r 29.97 -ac 2 -ar 48000 -y out.dv

ffmetadata
==========

FFmpeg metadata muxer.

This muxer writes the streams metadata in the ffmetadata format.

See the Metadata chapter (ffmpeg-formats) for information about the format.

Example
-------

Use ffmpeg to extract metadata from an input file to a metadata.ffmeta file in ffmetadata format:

     ffmpeg -i INPUT -f ffmetadata metadata.ffmeta

fifo
====

FIFO (First-In First-Out) muxer.

The fifo pseudo-muxer allows the separation of encoding and muxing by using a first-in-first-out queue and running the actual muxer in a separate thread.

This is especially useful in combination with the tee muxer and can be used to send data to several destinations with different reliability/writing speed/latency.

The target muxer is either selected from the output name or specified through the fifo_format option.

The behavior of the fifo muxer if the queue fills up or if the output fails (e.g. if a packet cannot be written to the output) is selectable:

  * Output can be transparently restarted with configurable delay between retries based on real time or time of the processed stream.

  * Encoding can be blocked during temporary failure, or continue transparently dropping packets in case the FIFO queue fills up.

API users should be aware that callback functions (interrupt_callback, io_open and io_close) used within its AVFormatContext must be thread-safe.

Options
-------

attempt_recovery BOOL
     If failure occurs, attempt to recover the output. This is especially useful when used with network output, since it makes it possible to restart streaming transparently. By default this option is set to false.

drop_pkts_on_overflow BOOL
     If set to true, in case the fifo queue fills up, packets will be dropped rather than blocking the encoder. This makes it possible to continue streaming without delaying the input, at the cost of omitting part of the stream. By default this option is set to false, so in such cases the encoder will be blocked until the muxer processes some of the packets and none of them is lost.

fifo_format FORMAT_NAME
     Specify the format name. Useful if it cannot be guessed from the output name suffix.

format_opts OPTIONS
     Specify format options for the underlying muxer. Muxer options can be specified as a list of KEY=VALUE pairs separated by ':'.

max_recovery_attempts COUNT
     Set maximum number of successive unsuccessful recovery attempts after which the output fails permanently. By default this option is set to 0 (unlimited).

queue_size SIZE
     Specify size of the queue as a number of packets. Default value is 60.

recover_any_error BOOL
     If set to true, recovery will be attempted regardless of type of the error causing the failure. By default this option is set to false and in case of certain (usually permanent) errors the recovery is not attempted even when the attempt_recovery option is set to true.

recovery_wait_streamtime BOOL
     If set to false, the real time is used when waiting for the recovery attempt (i.e. the recovery will be attempted after the time specified by the recovery_wait_time option).

     If set to true, the time of the processed stream is taken into account instead (i.e. the recovery will be attempted after discarding the packets corresponding to the recovery_wait_time option).

     By default this option is set to false.

recovery_wait_time DURATION
     Specify waiting time in seconds before the next recovery attempt after previous unsuccessful recovery attempt. Default value is 5.

restart_with_keyframe BOOL
     Specify whether to wait for the keyframe after recovering from queue overflow or failure. This option is set to false by default.

timeshift DURATION
     Buffer the specified amount of packets and delay writing the output. Note that the value of the queue_size option must be big enough to store the packets for timeshift. At the end of the input the fifo buffer is flushed at realtime speed.

Example
-------

Use ffmpeg to stream to an RTMP server, continue processing the stream at real-time rate even in case of temporary failure (network outage) and attempt to recover streaming every second indefinitely:

     ffmpeg -re -i ... -c:v libx264 -c:a aac -f fifo -fifo_format flv \
       -drop_pkts_on_overflow 1 -attempt_recovery 1 -recovery_wait_time 1 \
       -map 0:v -map 0:a rtmp://example.com/live/stream_name

film_cpk
========

Sega film (.cpk) muxer.

This format was used as internal format for several Sega games.

For more information regarding the Sega film file format, visit http://wiki.multimedia.cx/index.php?title=Sega_FILM.

It accepts at maximum one cinepak or raw video stream, and at maximum one audio stream.

filmstrip
=========

Adobe Filmstrip muxer.

This format is used by several Adobe tools to store a generated filmstrip export. It accepts a single raw video stream.

fits
====

Flexible Image Transport System (FITS) muxer.

This image format is used to store astronomical data.

For more information regarding the format, visit https://fits.gsfc.nasa.gov.

flac
====

Raw FLAC audio muxer.

This muxer accepts exactly one FLAC audio stream. Additionally, it is possible to add images with disposition attached_pic.

Options
-------

write_header BOOL
     write the file header if set to true, default is true

Example
-------

Use ffmpeg to store the audio stream from an input file, together with several pictures used with attached_pic disposition:

     ffmpeg -i INPUT -i pic1.png -i pic2.jpg -map 0:a -map 1 -map 2 -disposition:v attached_pic OUTPUT

flv
===

Adobe Flash Video Format muxer.

Options
-------

flvflags FLAGS
     Possible values:

     aac_seq_header_detect
          Place AAC sequence header based on audio stream data.

     no_sequence_end
          Disable sequence end tag.

     no_metadata
          Disable metadata tag.

     no_duration_filesize
          Disable duration and filesize in metadata when they are equal to zero at the end of stream. (Be used to non-seekable living stream).

     add_keyframe_index
          Used to facilitate seeking; particularly for HTTP pseudo streaming.

framecrc
========

Per-packet CRC (Cyclic Redundancy Check) testing format.

This muxer computes and prints the Adler-32 CRC for each audio and video packet. By default audio frames are converted to signed 16-bit raw audio and video frames to raw video before computing the CRC.

The output of the muxer consists of a line for each audio and video packet of the form:

     STREAM_INDEX, PACKET_DTS, PACKET_PTS, PACKET_DURATION, PACKET_SIZE, 0xCRC

CRC is a hexadecimal number 0-padded to 8 digits containing the CRC of the packet.

Examples
--------

For example to compute the CRC of the audio and video frames in INPUT, converted to raw audio and video packets, and store it in the file out.crc:

     ffmpeg -i INPUT -f framecrc out.crc

To print the information to stdout, use the command:

     ffmpeg -i INPUT -f framecrc -

With ffmpeg, you can select the output format to which the audio and video frames are encoded before computing the CRC for each packet by specifying the audio and video codec. For example, to compute the CRC of each decoded input audio frame converted to PCM unsigned 8-bit and of each decoded input video frame converted to MPEG-2 video, use the command:

     ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -

See also the crc muxer.

framehash
=========

Per-packet hash testing format.

This muxer computes and prints a cryptographic hash for each audio and video packet. This can be used for packet-by-packet equality checks without having to individually do a binary comparison on each.

By default audio frames are converted to signed 16-bit raw audio and video frames to raw video before computing the hash, but the output of explicit conversions to other codecs can also be used. It uses the SHA-256 cryptographic hash function by default, but supports several other algorithms.

The output of the muxer consists of a line for each audio and video packet of the form:

     STREAM_INDEX, PACKET_DTS, PACKET_PTS, PACKET_DURATION, PACKET_SIZE, HASH

HASH is a hexadecimal number representing the computed hash for the packet.

hash ALGORITHM
     Use the cryptographic hash function specified by the string ALGORITHM. Supported values include MD5, murmur3, RIPEMD128, RIPEMD160, RIPEMD256, RIPEMD320, SHA160, SHA224, SHA256 (default), SHA512/224, SHA512/256, SHA384, SHA512, CRC32 and adler32.

Examples
--------

To compute the SHA-256 hash of the audio and video frames in INPUT, converted to raw audio and video packets, and store it in the file out.sha256:

     ffmpeg -i INPUT -f framehash out.sha256

To print the information to stdout, using the MD5 hash function, use the command:

     ffmpeg -i INPUT -f framehash -hash md5 -

See also the hash muxer.

framemd5
========

Per-packet MD5 testing format.

This is a variant of the framehash muxer. Unlike that muxer, it defaults to using the MD5 hash function.

Examples
--------

To compute the MD5 hash of the audio and video frames in INPUT, converted to raw audio and video packets, and store it in the file out.md5:

     ffmpeg -i INPUT -f framemd5 out.md5

To print the information to stdout, use the command:

     ffmpeg -i INPUT -f framemd5 -

See also the framehash and md5 muxers.

gif
===

Animated GIF muxer.

Note that the GIF format has a very large time base: the delay between two frames can therefore not be smaller than one centi second.

Options
-------

loop BOOL
     Set the number of times to loop the output. Use -1 for no loop, 0 for looping indefinitely (default).

final_delay DELAY
     Force the delay (expressed in centiseconds) after the last frame. Each frame ends with a delay until the next frame. The default is -1, which is a special value to tell the muxer to reuse the previous delay. In case of a loop, you might want to customize this value to mark a pause for instance.

Example
-------

Encode a gif looping 10 times, with a 5 seconds delay between the loops:

     ffmpeg -i INPUT -loop 10 -final_delay 500 out.gif

Note 1: if you wish to extract the frames into separate GIF files, you need to force the image2 muxer:

     ffmpeg -i INPUT -c:v gif -f image2 "out%d.gif"

gxf
===

General eXchange Format (GXF) muxer.

GXF was developed by Grass Valley Group, then standardized by SMPTE as SMPTE 360M and was extended in SMPTE RDD 14-2007 to include high-definition video resolutions.

It accepts at most one video stream with codec mjpeg, or mpeg1video, or mpeg2video, or dvvideo with resolution 512x480 or 608x576, and several audio streams with rate 48000Hz and codec pcm16_le.

hash
====

Hash testing format.

This muxer computes and prints a cryptographic hash of all the input audio and video frames. This can be used for equality checks without having to do a complete binary comparison.

By default audio frames are converted to signed 16-bit raw audio and video frames to raw video before computing the hash, but the output of explicit conversions to other codecs can also be used. Timestamps are ignored. It uses the SHA-256 cryptographic hash function by default, but supports several other algorithms.

The output of the muxer consists of a single line of the form: ALGO=HASH, where ALGO is a short string representing the hash function used, and HASH is a hexadecimal number representing the computed hash.

hash ALGORITHM
     Use the cryptographic hash function specified by the string ALGORITHM. Supported values include MD5, murmur3, RIPEMD128, RIPEMD160, RIPEMD256, RIPEMD320, SHA160, SHA224, SHA256 (default), SHA512/224, SHA512/256, SHA384, SHA512, CRC32 and adler32.

Examples
--------

To compute the SHA-256 hash of the input converted to raw audio and video, and store it in the file out.sha256:

     ffmpeg -i INPUT -f hash out.sha256

To print an MD5 hash to stdout use the command:

     ffmpeg -i INPUT -f hash -hash md5 -

See also the framehash muxer.

hds
===

HTTP Dynamic Streaming (HDS) muxer.

HTTP dynamic streaming, or HDS, is an adaptive bitrate streaming method developed by Adobe. HDS delivers MP4 video content over HTTP connections. HDS can be used for on-demand streaming or live streaming.

This muxer creates an .f4m (Adobe Flash Media Manifest File) manifest, an .abst (Adobe Bootstrap File) for each stream, and segment files in a directory specified as the output.

These needs to be accessed by an HDS player through HTTPS for it to be able to perform playback on the generated stream.

Options
-------

extra_window_size INT
     number of fragments kept outside of the manifest before removing from disk

min_frag_duration MICROSECONDS
     minimum fragment duration (in microseconds), default value is 1 second (10000000)

remove_at_exit BOOL
     remove all fragments when finished when set to true

window_size INT
     number of fragments kept in the manifest, if set to a value different from 0. By default all segments are kept in the output directory.

Example
-------

Use ffmpeg to generate HDS files to the output.hds directory in real-time rate:

     ffmpeg -re -i INPUT -f hds -b:v 200k output.hds

hls
===

Apple HTTP Live Streaming muxer that segments MPEG-TS according to the HTTP Live Streaming (HLS) specification.

It creates a playlist file, and one or more segment files. The output filename specifies the playlist filename.

By default, the muxer creates a file for each segment produced. These files have the same name as the playlist, followed by a sequential number and a .ts extension.

Make sure to require a closed GOP when encoding and to set the GOP size to fit your segment time constraint.

For example, to convert an input file with ffmpeg:

     ffmpeg -i in.mkv -c:v h264 -flags +cgop -g 30 -hls_time 1 out.m3u8

This example will produce the playlist, out.m3u8, and segment files: out0.ts, out1.ts, out2.ts, etc.

See also the segment muxer, which provides a more generic and flexible implementation of a segmenter, and can be used to perform HLS segmentation.

Options
-------

hls_init_time DURATION
     Set the initial target segment length. Default value is 0.

     DURATION must be a time duration specification, see the Time duration section in the ffmpeg-utils(1) manual (ffmpeg-utils).

     Segment will be cut on the next key frame after this time has passed on the first m3u8 list. After the initial playlist is filled, ffmpeg will cut segments at duration equal to hls_time.

hls_time DURATION
     Set the target segment length. Default value is 2.

     DURATION must be a time duration specification, see the Time duration section in the ffmpeg-utils(1) manual (ffmpeg-utils). Segment will be cut on the next key frame after this time has passed.

hls_list_size SIZE
     Set the maximum number of playlist entries. If set to 0 the list file will contain all the segments. Default value is 5.

hls_delete_threshold SIZE
     Set the number of unreferenced segments to keep on disk before hls_flags delete_segments deletes them. Increase this to allow continue clients to download segments which were recently referenced in the playlist. Default value is 1, meaning segments older than hls_list_size+1 will be deleted.

hls_start_number_source SOURCE
     Start the playlist sequence number (#EXT-X-MEDIA-SEQUENCE) according to the specified source. Unless hls_flags single_file is set, it also specifies source of starting sequence numbers of segment and subtitle filenames. In any case, if hls_flags append_list is set and read playlist sequence number is greater than the specified start sequence number, then that value will be used as start value.

     It accepts the following values:

     generic (default)
          Set the start numbers according to the start_number option value.

     epoch
          Set the start number as the seconds since epoch (1970-01-01 00:00:00).

     epoch_us
          Set the start number as the microseconds since epoch (1970-01-01 00:00:00).

     datetime
          Set the start number based on the current date/time as YYYYmmddHHMMSS. e.g. 20161231235759.

start_number NUMBER
     Start the playlist sequence number (#EXT-X-MEDIA-SEQUENCE) from the specified NUMBER when hls_start_number_source value is GENERIC. (This is the default case.) Unless hls_flags single_file is set, it also specifies starting sequence numbers of segment and subtitle filenames. Default value is 0.

hls_allow_cache BOOL
     Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments.

hls_base_url BASEURL
     Append BASEURL to every entry in the playlist. Useful to generate playlists with absolute paths.

     Note that the playlist sequence number must be unique for each segment and it is not to be confused with the segment filename sequence number which can be cyclic, for example if the wrap option is specified.

hls_segment_filename FILENAME
     Set the segment filename. Unless the hls_flags option is set with single_file, FILENAME is used as a string format with the segment number appended.

     For example:

          ffmpeg -i in.nut -hls_segment_filename 'file%03d.ts' out.m3u8

     will produce the playlist, out.m3u8, and segment files: file000.ts, file001.ts, file002.ts, etc.

     FILENAME may contain a full path or relative path specification, but only the file name part without any path will be contained in the m3u8 segment list. Should a relative path be specified, the path of the created segment files will be relative to the current working directory. When strftime_mkdir is set, the whole expanded value of FILENAME will be written into the m3u8 segment list.

     When var_stream_map is set with two or more variant streams, the FILENAME pattern must contain the string "%v", and this string will be expanded to the position of variant stream index in the generated segment file names.

     For example:

          ffmpeg -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
            -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" \
            -hls_segment_filename 'file_%v_%03d.ts' out_%v.m3u8

     will produce the playlists segment file sets: file_0_000.ts, file_0_001.ts, file_0_002.ts, etc. and file_1_000.ts, file_1_001.ts, file_1_002.ts, etc.

     The string "%v" may be present in the filename or in the last directory name containing the file, but only in one of them. (Additionally, %v may appear multiple times in the last sub-directory or filename.) If the string %v is present in the directory name, then sub-directories are created after expanding the directory name pattern. This enables creation of segments corresponding to different variant streams in subdirectories.

     For example:

          ffmpeg -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
            -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" \
            -hls_segment_filename 'vs%v/file_%03d.ts' vs%v/out.m3u8

     will produce the playlists segment file sets: vs0/file_000.ts, vs0/file_001.ts, vs0/file_002.ts, etc. and vs1/file_000.ts, vs1/file_001.ts, vs1/file_002.ts, etc.

strftime BOOL
     Use strftime() on FILENAME to expand the segment filename with localtime. The segment number is also available in this mode, but to use it, you need to set second_level_segment_index in the hls_flag and %%d will be the specifier.

     For example:

          ffmpeg -i in.nut -strftime 1 -hls_segment_filename 'file-%Y%m%d-%s.ts' out.m3u8

     will produce the playlist, out.m3u8, and segment files: file-20160215-1455569023.ts, file-20160215-1455569024.ts, etc. Note: On some systems/environments, the %s specifier is not available. See strftime() documentation.

     For example:

          ffmpeg -i in.nut -strftime 1 -hls_flags second_level_segment_index -hls_segment_filename 'file-%Y%m%d-%%04d.ts' out.m3u8

     will produce the playlist, out.m3u8, and segment files: file-20160215-0001.ts, file-20160215-0002.ts, etc.

strftime_mkdir BOOL
     Used together with strftime, it will create all subdirectories which are present in the expanded values of option hls_segment_filename.

     For example:

          ffmpeg -i in.nut -strftime 1 -strftime_mkdir 1 -hls_segment_filename '%Y%m%d/file-%Y%m%d-%s.ts' out.m3u8

     will create a directory 201560215 (if it does not exist), and then produce the playlist, out.m3u8, and segment files: 20160215/file-20160215-1455569023.ts, 20160215/file-20160215-1455569024.ts, etc.

     For example:

          ffmpeg -i in.nut -strftime 1 -strftime_mkdir 1 -hls_segment_filename '%Y/%m/%d/file-%Y%m%d-%s.ts' out.m3u8

     will create a directory hierarchy 2016/02/15 (if any of them do not exist), and then produce the playlist, out.m3u8, and segment files: 2016/02/15/file-20160215-1455569023.ts, 2016/02/15/file-20160215-1455569024.ts, etc.

hls_segment_options OPTIONS_LIST
     Set output format options using a :-separated list of key=value parameters. Values containing : special characters must be escaped.

hls_key_info_file KEY_INFO_FILE
     Use the information in KEY_INFO_FILE for segment encryption. The first line of KEY_INFO_FILE specifies the key URI written to the playlist. The key URL is used to access the encryption key during playback. The second line specifies the path to the key file used to obtain the key during the encryption process. The key file is read as a single packed array of 16 octets in binary format. The optional third line specifies the initialization vector (IV) as a hexadecimal string to be used instead of the segment sequence number (default) for encryption. Changes to KEY_INFO_FILE will result in segment encryption with the new key/IV and an entry in the playlist for the new key URI/IV if hls_flags periodic_rekey is enabled.

     Key info file format:

          KEY URI
          KEY FILE PATH
          IV (optional)

     Example key URIs:

          http://server/file.key
          /path/to/file.key
          file.key

     Example key file paths:

          file.key
          /path/to/file.key

     Example IV:

          0123456789ABCDEF0123456789ABCDEF

     Key info file example:

          http://server/file.key
          /path/to/file.key
          0123456789ABCDEF0123456789ABCDEF

     Example shell script:

          #!/bin/sh
          BASE_URL=${1:-'.'}
          openssl rand 16 > file.key
          echo $BASE_URL/file.key > file.keyinfo
          echo file.key >> file.keyinfo
          echo $(openssl rand -hex 16) >> file.keyinfo
          ffmpeg -f lavfi -re -i testsrc -c:v h264 -hls_flags delete_segments \
            -hls_key_info_file file.keyinfo out.m3u8

hls_enc BOOL
     Enable (1) or disable (0) the AES128 encryption. When enabled every segment generated is encrypted and the encryption key is saved as PLAYLIST NAME.key.

hls_enc_key KEY
     Specify a 16-octet key to encrypt the segments, by default it is randomly generated.

hls_enc_key_url KEYURL
     If set, KEYURL is prepended instead of BASEURL to the key filename in the playlist.

hls_enc_iv IV
     Specify the 16-octet initialization vector for every segment instead of the autogenerated ones.

hls_segment_type FLAGS
     Possible values:

     mpegts
          Output segment files in MPEG-2 Transport Stream format. This is compatible with all HLS versions.

     fmp4
          Output segment files in fragmented MP4 format, similar to MPEG-DASH. fmp4 files may be used in HLS version 7 and above.

hls_fmp4_init_filename FILENAME
     Set filename for the fragment files header file, default filename is init.mp4.

     When strftime is enabled, FILENAME is expanded to the segment filename with localtime.

     For example:

          ffmpeg -i in.nut -hls_segment_type fmp4 -strftime 1 -hls_fmp4_init_filename "%s_init.mp4" out.m3u8

     will produce init like this 1602678741_init.mp4.

hls_fmp4_init_resend BOOL
     Resend init file after m3u8 file refresh every time, default is 0.

     When var_stream_map is set with two or more variant streams, the FILENAME pattern must contain the string "%v", this string specifies the position of variant stream index in the generated init file names. The string "%v" may be present in the filename or in the last directory name containing the file. If the string is present in the directory name, then sub-directories are created after expanding the directory name pattern. This enables creation of init files corresponding to different variant streams in subdirectories.

hls_flags FLAGS
     Possible values:

     single_file
          If this flag is set, the muxer will store all segments in a single MPEG-TS file, and will use byte ranges in the playlist. HLS playlists generated with this way will have the version number 4.

          For example:

               ffmpeg -i in.nut -hls_flags single_file out.m3u8

          will produce the playlist, out.m3u8, and a single segment file, out.ts.

     delete_segments
          Segment files removed from the playlist are deleted after a period of time equal to the duration of the segment plus the duration of the playlist.

     append_list
          Append new segments into the end of old segment list, and remove the #EXT-X-ENDLIST from the old segment list.

     round_durations
          Round the duration info in the playlist file segment info to integer values, instead of using floating point. If there are no other features requiring higher HLS versions be used, then this will allow ffmpeg to output a HLS version 2 m3u8.

     discont_start
          Add the #EXT-X-DISCONTINUITY tag to the playlist, before the first segment's information.

     omit_endlist
          Do not append the EXT-X-ENDLIST tag at the end of the playlist.

     periodic_rekey
          The file specified by hls_key_info_file will be checked periodically and detect updates to the encryption info. Be sure to replace this file atomically, including the file containing the AES encryption key.

     independent_segments
          Add the #EXT-X-INDEPENDENT-SEGMENTS tag to playlists that has video segments and when all the segments of that playlist are guaranteed to start with a key frame.

     iframes_only
          Add the #EXT-X-I-FRAMES-ONLY tag to playlists that has video segments and can play only I-frames in the #EXT-X-BYTERANGE mode.

     split_by_time
          Allow segments to start on frames other than key frames. This improves behavior on some players when the time between key frames is inconsistent, but may make things worse on others, and can cause some oddities during seeking. This flag should be used with the hls_time option.

     program_date_time
          Generate EXT-X-PROGRAM-DATE-TIME tags.

     second_level_segment_index
          Make it possible to use segment indexes as %%d in the hls_segment_filename option expression besides date/time values when strftime option is on. To get fixed width numbers with trailing zeroes, %%0xd format is available where x is the required width.

     second_level_segment_size
          Make it possible to use segment sizes (counted in bytes) as %%s in hls_segment_filename option expression besides date/time values when strftime is on. To get fixed width numbers with trailing zeroes, %%0xs format is available where x is the required width.

     second_level_segment_duration
          Make it possible to use segment duration (calculated in microseconds) as %%t in hls_segment_filename option expression besides date/time values when strftime is on. To get fixed width numbers with trailing zeroes, %%0xt format is available where x is the required width.

          For example:

               ffmpeg -i sample.mpeg \
                  -f hls -hls_time 3 -hls_list_size 5 \
                  -hls_flags second_level_segment_index+second_level_segment_size+second_level_segment_duration \
                  -strftime 1 -strftime_mkdir 1 -hls_segment_filename "segment_%Y%m%d%H%M%S_%%04d_%%08s_%%013t.ts" stream.m3u8

          will produce segments like this: segment_20170102194334_0003_00122200_0000003000000.ts, segment_20170102194334_0004_00120072_0000003000000.ts etc.

     temp_file
          Write segment data to filename.tmp and rename to filename only once the segment is complete.

          A webserver serving up segments can be configured to reject requests to *.tmp to prevent access to in-progress segments before they have been added to the m3u8 playlist.

          This flag also affects how m3u8 playlist files are created. If this flag is set, all playlist files will be written into a temporary file and renamed after they are complete, similarly as segments are handled. But playlists with file protocol and with hls_playlist_type type other than vod are always written into a temporary file regardless of this flag.

          Master playlist files specified with master_pl_name, if any, with file protocol, are always written into temporary file regardless of this flag if master_pl_publish_rate value is other than zero.

hls_playlist_type TYPE
     If type is event, emit #EXT-X-PLAYLIST-TYPE:EVENT in the m3u8 header. This forces hls_list_size to 0; the playlist can only be appended to.

     If type is vod, emit #EXT-X-PLAYLIST-TYPE:VOD in the m3u8 header. This forces hls_list_size to 0; the playlist must not change.

method METHOD
     Use the given HTTP method to create the hls files.

     For example:

          ffmpeg -re -i in.ts -f hls -method PUT http://example.com/live/out.m3u8

     will upload all the mpegts segment files to the HTTP server using the HTTP PUT method, and update the m3u8 files every refresh times using the same method. Note that the HTTP server must support the given method for uploading files.

http_user_agent AGENT
     Override User-Agent field in HTTP header. Applicable only for HTTP output.

var_stream_map STREAM_MAP
     Specify a map string defining how to group the audio, video and subtitle streams into different variant streams. The variant stream groups are separated by space.

     Expected string format is like this "a:0,v:0 a:1,v:1 ....". Here a:, v:, s: are the keys to specify audio, video and subtitle streams respectively. Allowed values are 0 to 9 (limited just based on practical usage).

     When there are two or more variant streams, the output filename pattern must contain the string "%v": this string specifies the position of variant stream index in the output media playlist filenames. The string "%v" may be present in the filename or in the last directory name containing the file. If the string is present in the directory name, then sub-directories are created after expanding the directory name pattern. This enables creation of variant streams in subdirectories.

     A few examples follow.

       * Create two hls variant streams. The first variant stream will contain video stream of bitrate 1000k and audio stream of bitrate 64k and the second variant stream will contain video stream of bitrate 256k and audio stream of bitrate 32k. Here, two media playlist with file names out_0.m3u8 and out_1.m3u8 will be created.

               ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
                 -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" \
                 http://example.com/live/out_%v.m3u8

       * If you want something meaningful text instead of indexes in result names, you may specify names for each or some of the variants. The following example will create two hls variant streams as in the previous one. But here, the two media playlist with file names out_my_hd.m3u8 and out_my_sd.m3u8 will be created.

               ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
                 -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" \
                 http://example.com/live/out_%v.m3u8

       * Create three hls variant streams. The first variant stream will be a video only stream with video bitrate 1000k, the second variant stream will be an audio only stream with bitrate 64k and the third variant stream will be a video only stream with bitrate 256k. Here, three media playlist with file names out_0.m3u8, out_1.m3u8 and out_2.m3u8 will be created.

               ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k \
                 -map 0:v -map 0:a -map 0:v -f hls -var_stream_map "v:0 a:0 v:1" \
                 http://example.com/live/out_%v.m3u8

       * Create the variant streams in subdirectories. Here, the first media playlist is created at http://example.com/live/vs_0/out.m3u8 and the second one at http://example.com/live/vs_1/out.m3u8.

               ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
                 -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" \
                 http://example.com/live/vs_%v/out.m3u8

       * Create two audio only and two video only variant streams. In addition to the #EXT-X-STREAM-INF tag for each variant stream in the master playlist, the #EXT-X-MEDIA tag is also added for the two audio only variant streams and they are mapped to the two video only variant streams with audio group names 'aud_low' and 'aud_high'. By default, a single hls variant containing all the encoded streams is created.

               ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k -b:v:1 3000k  \
                 -map 0:a -map 0:a -map 0:v -map 0:v -f hls \
                 -var_stream_map "a:0,agroup:aud_low a:1,agroup:aud_high v:0,agroup:aud_low v:1,agroup:aud_high" \
                 -master_pl_name master.m3u8 \
                 http://example.com/live/out_%v.m3u8

       * Create two audio only and one video only variant streams. In addition to the #EXT-X-STREAM-INF tag for each variant stream in the master playlist, the #EXT-X-MEDIA tag is also added for the two audio only variant streams and they are mapped to the one video only variant streams with audio group name 'aud_low', and the audio group have default stat is NO or YES. By default, a single hls variant containing all the encoded streams is created.

               ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k \
                 -map 0:a -map 0:a -map 0:v -f hls \
                 -var_stream_map "a:0,agroup:aud_low,default:yes a:1,agroup:aud_low v:0,agroup:aud_low" \
                 -master_pl_name master.m3u8 \
                 http://example.com/live/out_%v.m3u8

       * Create two audio only and one video only variant streams. In addition to the #EXT-X-STREAM-INF tag for each variant stream in the master playlist, the #EXT-X-MEDIA tag is also added for the two audio only variant streams and they are mapped to the one video only variant streams with audio group name 'aud_low', and the audio group have default stat is NO or YES, and one audio have and language is named ENG, the other audio language is named CHN. By default, a single hls variant containing all the encoded streams is created.

               ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k \
                 -map 0:a -map 0:a -map 0:v -f hls \
                 -var_stream_map "a:0,agroup:aud_low,default:yes,language:ENG a:1,agroup:aud_low,language:CHN v:0,agroup:aud_low" \
                 -master_pl_name master.m3u8 \
                 http://example.com/live/out_%v.m3u8

       * Create a single variant stream. Add the #EXT-X-MEDIA tag with TYPE=SUBTITLES in the master playlist with webvtt subtitle group name 'subtitle' and optional subtitle name, e.g. 'English'. Make sure the input file has one text subtitle stream at least.

               ffmpeg -y -i input_with_subtitle.mkv \
                -b:v:0 5250k -c:v h264 -pix_fmt yuv420p -profile:v main -level 4.1 \
                -b:a:0 256k \
                -c:s webvtt -c:a mp2 -ar 48000 -ac 2 -map 0:v -map 0:a:0 -map 0:s:0 \
                -f hls -var_stream_map "v:0,a:0,s:0,sgroup:subtitle,sname:English" \
                -master_pl_name master.m3u8 -t 300 -hls_time 10 -hls_init_time 4 -hls_list_size \
                10 -master_pl_publish_rate 10 -hls_flags \
                delete_segments+discont_start+split_by_time ./tmp/video.m3u8

cc_stream_map CC_STREAM_MAP
     Map string which specifies different closed captions groups and their attributes. The closed captions stream groups are separated by space.

     Expected string format is like this "ccgroup:<group name>,instreamid:<INSTREAM-ID>,language:<language code> ....". 'ccgroup' and 'instreamid' are mandatory attributes. 'language' is an optional attribute.

     The closed captions groups configured using this option are mapped to different variant streams by providing the same 'ccgroup' name in the var_stream_map string.

     For example:

          ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
            -a53cc:0 1 -a53cc:1 1 \
            -map 0:v -map 0:a -map 0:v -map 0:a -f hls \
            -cc_stream_map "ccgroup:cc,instreamid:CC1,language:en ccgroup:cc,instreamid:CC2,language:sp" \
            -var_stream_map "v:0,a:0,ccgroup:cc v:1,a:1,ccgroup:cc" \
            -master_pl_name master.m3u8 \
            http://example.com/live/out_%v.m3u8

     will add two #EXT-X-MEDIA tags with TYPE=CLOSED-CAPTIONS in the master playlist for the INSTREAM-IDs 'CC1' and 'CC2'. Also, it will add CLOSED-CAPTIONS attribute with group name 'cc' for the two output variant streams.

     If var_stream_map is not set, then the first available ccgroup in cc_stream_map is mapped to the output variant stream.

     For example:

          ffmpeg -re -i in.ts -b:v 1000k -b:a 64k -a53cc 1 -f hls \
            -cc_stream_map "ccgroup:cc,instreamid:CC1,language:en" \
            -master_pl_name master.m3u8 \
            http://example.com/live/out.m3u8

     this will add #EXT-X-MEDIA tag with TYPE=CLOSED-CAPTIONS in the master playlist with group name 'cc', language 'en' (english) and INSTREAM-ID 'CC1'. Also, it will add CLOSED-CAPTIONS attribute with group name 'cc' for the output variant stream.

master_pl_name NAME
     Create HLS master playlist with the given name.

     For example:

          ffmpeg -re -i in.ts -f hls -master_pl_name master.m3u8 http://example.com/live/out.m3u8

     creates an HLS master playlist with name master.m3u8 which is published at http://example.com/live/.

master_pl_publish_rate COUNT
     Publish master play list repeatedly every after specified number of segment intervals.

     For example:

          ffmpeg -re -i in.ts -f hls -master_pl_name master.m3u8 \
          -hls_time 2 -master_pl_publish_rate 30 http://example.com/live/out.m3u8

     creates an HLS master playlist with name master.m3u8 and keeps publishing it repeatedly every after 30 segments i.e. every after 60s.

http_persistent BOOL
     Use persistent HTTP connections. Applicable only for HTTP output.

timeout TIMEOUT
     Set timeout for socket I/O operations. Applicable only for HTTP output.

ignore_io_errors BOOL
     Ignore IO errors during open, write and delete. Useful for long-duration runs with network output.

headers HEADERS
     Set custom HTTP headers, can override built in default headers. Applicable only for HTTP output.

iamf
====

Immersive Audio Model and Formats (IAMF) muxer.

IAMF is used to provide immersive audio content for presentation on a wide range of devices in both streaming and offline applications. These applications include internet audio streaming, multicasting/broadcasting services, file download, gaming, communication, virtual and augmented reality, and others. In these applications, audio may be played back on a wide range of devices, e.g., headphones, mobile phones, tablets, TVs, sound bars, home theater systems, and big screens.

This format was promoted and designed by Alliance for Open Media.

For more information about this format, see https://aomedia.org/iamf/.

ico
===

ICO file muxer.

Microsoft's icon file format (ICO) has some strict limitations that should be noted:

  * Size cannot exceed 256 pixels in any dimension

  * Only BMP and PNG images can be stored

  * If a BMP image is used, it must be one of the following pixel formats:

          BMP Bit Depth      FFmpeg Pixel Format
          1bit               pal8
          4bit               pal8
          8bit               pal8
          16bit              rgb555le
          24bit              bgr24
          32bit              bgra

  * If a BMP image is used, it must use the BITMAPINFOHEADER DIB header

  * If a PNG image is used, it must use the rgba pixel format

ilbc
====

Internet Low Bitrate Codec (iLBC) raw muxer.

It accepts a single ilbc audio stream.

image2, image2pipe
==================

Image file muxer.

The image2 muxer writes video frames to image files.

The output filenames are specified by a pattern, which can be used to produce sequentially numbered series of files. The pattern may contain the string "%d" or "%0Nd", this string specifies the position of the characters representing a numbering in the filenames. If the form "%0Nd" is used, the string representing the number in each filename is 0-padded to N digits. The literal character '%' can be specified in the pattern with the string "%%".

If the pattern contains "%d" or "%0Nd", the first filename of the file list specified will contain the number 1, all the following numbers will be sequential.

The pattern may contain a suffix which is used to automatically determine the format of the image files to write.

For example the pattern "img-%03d.bmp" will specify a sequence of filenames of the form img-001.bmp, img-002.bmp, ..., img-010.bmp, etc. The pattern "img%%-%d.jpg" will specify a sequence of filenames of the form img%-1.jpg, img%-2.jpg, ..., img%-10.jpg, etc.

The image muxer supports the .Y.U.V image file format. This format is special in that each image frame consists of three files, for each of the YUV420P components. To read or write this image file format, specify the name of the '.Y' file. The muxer will automatically open the '.U' and '.V' files as required.

The image2pipe muxer accepts the same options as the image2 muxer, but ignores the pattern verification and expansion, as it is supposed to write to the command output rather than to an actual stored file.

Options
-------

frame_pts BOOL
     If set to 1, expand the filename with the packet PTS (presentation time stamp). Default value is 0.

start_number COUNT
     Start the sequence from the specified number. Default value is 1.

update BOOL
     If set to 1, the filename will always be interpreted as just a filename, not a pattern, and the corresponding file will be continuously overwritten with new images. Default value is 0.

strftime BOOL
     If set to 1, expand the filename with date and time information from strftime(). Default value is 0.

atomic_writing BOOL
     Write output to a temporary file, which is renamed to target filename once writing is completed. Default is disabled.

protocol_opts OPTIONS_LIST
     Set protocol options as a :-separated list of key=value parameters. Values containing the : special character must be escaped.

Examples
--------

  * Use ffmpeg for creating a sequence of files img-001.jpeg, img-002.jpeg, ..., taking one image every second from the input video:

          ffmpeg -i in.avi -vsync cfr -r 1 -f image2 'img-%03d.jpeg'

     Note that with ffmpeg, if the format is not specified with the -f option and the output filename specifies an image file format, the image2 muxer is automatically selected, so the previous command can be written as:

          ffmpeg -i in.avi -vsync cfr -r 1 'img-%03d.jpeg'

     Note also that the pattern must not necessarily contain "%d" or "%0Nd", for example to create a single image file img.jpeg from the start of the input video you can employ the command:

          ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg

  * The strftime option allows you to expand the filename with date and time information. Check the documentation of the strftime() function for the syntax.

     To generate image files from the strftime() "%Y-%m-%d_%H-%M-%S" pattern, the following ffmpeg command can be used:

          ffmpeg -f v4l2 -r 1 -i /dev/video0 -f image2 -strftime 1 "%Y-%m-%d_%H-%M-%S.jpg"

  * Set the file name with current frame's PTS:

          ffmpeg -f v4l2 -r 1 -i /dev/video0 -copyts -f image2 -frame_pts true %d.jpg

  * Publish contents of your desktop directly to a WebDAV server every second:

          ffmpeg -f x11grab -framerate 1 -i :0.0 -q:v 6 -update 1 -protocol_opts method=PUT http://example.com/desktop.jpg

ircam
=====

Berkeley / IRCAM / CARL Sound Filesystem (BICSF) format muxer.

The Berkeley/IRCAM/CARL Sound Format, developed in the 1980s, is a result of the merging of several different earlier sound file formats and systems including the csound system developed by Dr Gareth Loy at the Computer Audio Research Lab (CARL) at UC San Diego, the IRCAM sound file system developed by Rob Gross and Dan Timis at the Institut de Recherche et Coordination Acoustique / Musique in Paris and the Berkeley Fast Filesystem.

It was developed initially as part of the Berkeley/IRCAM/CARL Sound Filesystem, a suite of programs designed to implement a filesystem for audio applications running under Berkeley UNIX. It was particularly popular in academic music research centres, and was used a number of times in the creation of early computer-generated compositions.

This muxer accepts a single audio stream containing PCM data.

ivf
===

On2 IVF muxer.

IVF was developed by On2 Technologies (formerly known as Duck Corporation), to store internally developed codecs.

This muxer accepts a single vp8, vp9, or av1 video stream.

jacosub
=======

JACOsub subtitle format muxer.

This muxer accepts a single jacosub subtitles stream.

For more information about the format, see http://unicorn.us.com/jacosub/jscripts.html.

kvag
====

Simon & Schuster Interactive VAG muxer.

This custom VAG container is used by some Simon & Schuster Interactive games such as "Real War", and "Real War: Rogue States".

This muxer accepts a single adpcm_ima_ssi audio stream.

lc3
===

Bluetooth SIG Low Complexity Communication Codec audio (LC3), or ETSI TS 103 634 Low Complexity Communication Codec plus (LC3plus).

This muxer accepts a single lc3 audio stream.

lrc
===

LRC lyrics file format muxer.

LRC (short for LyRiCs) is a computer file format that synchronizes song lyrics with an audio file, such as MP3, Vorbis, or MIDI.

This muxer accepts a single subrip or text subtitles stream.

Metadata
--------

The following metadata tags are converted to the format corresponding metadata:

title

album

artist

author

creator

encoder

encoder_version

If encoder_version is not explicitly set, it is automatically set to the libavformat version.

matroska
========

Matroska container muxer.

This muxer implements the matroska and webm container specs.

Metadata
--------

The recognized metadata settings in this muxer are:

title
     Set title name provided to a single track. This gets mapped to the FileDescription element for a stream written as attachment.

language
     Specify the language of the track in the Matroska languages form.

     The language can be either the 3 letters bibliographic ISO-639-2 (ISO 639-2/B) form (like "fre" for French), or a language code mixed with a country code for specialities in languages (like "fre-ca" for Canadian French).

stereo_mode
     Set stereo 3D video layout of two views in a single video track.

     The following values are recognized:

     mono
          video is not stereo

     left_right
          Both views are arranged side by side, Left-eye view is on the left

     bottom_top
          Both views are arranged in top-bottom orientation, Left-eye view is at bottom

     top_bottom
          Both views are arranged in top-bottom orientation, Left-eye view is on top

     checkerboard_rl
          Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first

     checkerboard_lr
          Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first

     row_interleaved_rl
          Each view is constituted by a row based interleaving, Right-eye view is first row

     row_interleaved_lr
          Each view is constituted by a row based interleaving, Left-eye view is first row

     col_interleaved_rl
          Both views are arranged in a column based interleaving manner, Right-eye view is first column

     col_interleaved_lr
          Both views are arranged in a column based interleaving manner, Left-eye view is first column

     anaglyph_cyan_red
          All frames are in anaglyph format viewable through red-cyan filters

     right_left
          Both views are arranged side by side, Right-eye view is on the left

     anaglyph_green_magenta
          All frames are in anaglyph format viewable through green-magenta filters

     block_lr
          Both eyes laced in one Block, Left-eye view is first

     block_rl
          Both eyes laced in one Block, Right-eye view is first

For example a 3D WebM clip can be created using the following command line:

     ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm

Options
-------

reserve_index_space SIZE
     By default, this muxer writes the index for seeking (called cues in Matroska terms) at the end of the file, because it cannot know in advance how much space to leave for the index at the beginning of the file. However for some use cases -- e.g.  streaming where seeking is possible but slow -- it is useful to put the index at the beginning of the file.

     If this option is set to a non-zero value, the muxer will reserve SIZE bytes of space in the file header and then try to write the cues there when the muxing finishes. If the reserved space does not suffice, no Cues will be written, the file will be finalized and writing the trailer will return an error. A safe size for most use cases should be about 50kB per hour of video.

     Note that cues are only written if the output is seekable and this option will have no effect if it is not.

cues_to_front BOOL
     If set, the muxer will write the index at the beginning of the file by shifting the main data if necessary. This can be combined with reserve_index_space in which case the data is only shifted if the initially reserved space turns out to be insufficient.

     This option is ignored if the output is unseekable.

cluster_size_limit SIZE
     Store at most the provided amount of bytes in a cluster.

     If not specified, the limit is set automatically to a sensible hardcoded fixed value.

cluster_time_limit DURATION
     Store at most the provided number of milliseconds in a cluster.

     If not specified, the limit is set automatically to a sensible hardcoded fixed value.

dash BOOL
     Create a WebM file conforming to WebM DASH specification. By default it is set to false.

dash_track_number INDEX
     Track number for the DASH stream. By default it is set to 1.

live BOOL
     Write files assuming it is a live stream. By default it is set to false.

allow_raw_vfw BOOL
     Allow raw VFW mode. By default it is set to false.

flipped_raw_rgb BOOL
     If set to true, store positive height for raw RGB bitmaps, which indicates bitmap is stored bottom-up. Note that this option does not flip the bitmap which has to be done manually beforehand, e.g. by using the vflip filter. Default is false and indicates bitmap is stored top down.

write_crc32 BOOL
     Write a CRC32 element inside every Level 1 element. By default it is set to true. This option is ignored for WebM.

default_mode MODE
     Control how the FlagDefault of the output tracks will be set. It influences which tracks players should play by default. The default mode is passthrough.

     infer
          Every track with disposition default will have the FlagDefault set. Additionally, for each type of track (audio, video or subtitle), if no track with disposition default of this type exists, then the first track of this type will be marked as default (if existing). This ensures that the default flag is set in a sensible way even if the input originated from containers that lack the concept of default tracks.

     infer_no_subs
          This mode is the same as infer except that if no subtitle track with disposition default exists, no subtitle track will be marked as default.

     passthrough
          In this mode the FlagDefault is set if and only if the AV_DISPOSITION_DEFAULT flag is set in the disposition of the corresponding stream.

md5
===

MD5 testing format.

This is a variant of the hash muxer. Unlike that muxer, it defaults to using the MD5 hash function.

See also the hash and framemd5 muxers.

Examples
--------

  * To compute the MD5 hash of the input converted to raw audio and video, and store it in the file out.md5:

          ffmpeg -i INPUT -f md5 out.md5

  * To print the MD5 hash to stdout:

          ffmpeg -i INPUT -f md5 -

mcc
===

Muxer for MacCaption MCC files, it supports MCC versions 1.0 and 2.0. MCC files store VANC data, which can include closed captions (EIA-608 and CEA-708), ancillary time code, pan-scan data, etc.

Options
-------

The muxer options are:

override_time_code_rate
     Override the Time Code Rate value in the output. Defaults to trying to deduce from the stream's time_base, which often doesn't work.

use_u_alias
     Use the U alias for the byte sequence E1h 00h 00h 00h. Disabled by default because some .mcc files disagree on whether it has 2 or 3 zero bytes.

mcc_version
     The MCC file format version. Must be either 1 or 2, defaults to 2.

creation_program
     The creation program. Defaults to this version of FFmpeg.

creation_time
     The creation time. Defaults to the current time.

Examples
--------

  * Extract a MXF SMPTE_436M_ANC stream from a MXF file and write it to a MCC file at 30 fps.

          ffmpeg -i input.mxf -c copy -map 0:d -override_time_code_rate 30 out.mcc

  * Extract EIA-608/CTA-708 closed captions from a .mp4 file and write them to a MCC file at 29.97 fps.

          ffmpeg -f lavfi -i "movie=input.mp4[out+subcc]" -c:s copy -map 0:s -override_time_code_rate 30000/1001 out.mcc

microdvd
========

MicroDVD subtitle format muxer.

This muxer accepts a single microdvd subtitles stream.

mmf
===

Synthetic music Mobile Application Format (SMAF) format muxer.

SMAF is a music data format specified by Yamaha for portable electronic devices, such as mobile phones and personal digital assistants.

This muxer accepts a single adpcm_yamaha audio stream.

mp3
===

The MP3 muxer writes a raw MP3 stream with the following optional features:

  * An ID3v2 metadata header at the beginning (enabled by default). Versions 2.3 and 2.4 are supported, the id3v2_version private option controls which one is used (3 or 4). Setting id3v2_version to 0 disables the ID3v2 header completely.

     The muxer supports writing attached pictures (APIC frames) to the ID3v2 header. The pictures are supplied to the muxer in form of a video stream with a single packet. There can be any number of those streams, each will correspond to a single APIC frame.  The stream metadata tags TITLE and COMMENT map to APIC DESCRIPTION and PICTURE TYPE respectively. See http://id3.org/id3v2.4.0-frames for allowed picture types.

     Note that the APIC frames must be written at the beginning, so the muxer will buffer the audio frames until it gets all the pictures. It is therefore advised to provide the pictures as soon as possible to avoid excessive buffering.

  * A Xing/LAME frame right after the ID3v2 header (if present). It is enabled by default, but will be written only if the output is seekable. The write_xing private option can be used to disable it.  The frame contains various information that may be useful to the decoder, like the audio duration or encoder delay.

  * A legacy ID3v1 tag at the end of the file (disabled by default). It may be enabled with the write_id3v1 private option, but as its capabilities are very limited, its usage is not recommended.

Examples:

Write an mp3 with an ID3v2.3 header and an ID3v1 footer:

     ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3

To attach a picture to an mp3 file select both the audio and the picture stream with map:

     ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1
     -metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3

Write a "clean" MP3 without any extra features:

     ffmpeg -i input.wav -write_xing 0 -id3v2_version 0 out.mp3

mpegts
======

MPEG transport stream muxer.

This muxer implements ISO 13818-1 and part of ETSI EN 300 468.

The recognized metadata settings in mpegts muxer are service_provider and service_name. If they are not set the default for service_provider is FFmpeg and the default for service_name is Service01.

Options
-------

The muxer options are:

mpegts_transport_stream_id INTEGER
     Set the transport_stream_id. This identifies a transponder in DVB. Default is 0x0001.

mpegts_original_network_id INTEGER
     Set the original_network_id. This is unique identifier of a network in DVB. Its main use is in the unique identification of a service through the path Original_Network_ID, Transport_Stream_ID. Default is 0x0001.

mpegts_service_id INTEGER
     Set the service_id, also known as program in DVB. Default is 0x0001.

mpegts_service_type INTEGER
     Set the program service_type. Default is digital_tv. Accepts the following options:

     hex_value
          Any hexadecimal value between 0x01 and 0xff as defined in ETSI 300 468.

     digital_tv
          Digital TV service.

     digital_radio
          Digital Radio service.

     teletext
          Teletext service.

     advanced_codec_digital_radio
          Advanced Codec Digital Radio service.

     mpeg2_digital_hdtv
          MPEG2 Digital HDTV service.

     advanced_codec_digital_sdtv
          Advanced Codec Digital SDTV service.

     advanced_codec_digital_hdtv
          Advanced Codec Digital HDTV service.

mpegts_pmt_start_pid INTEGER
     Set the first PID for PMTs. Default is 0x1000, minimum is 0x0020, maximum is 0x1ffa. This option has no effect in m2ts mode where the PMT PID is fixed 0x0100.

mpegts_start_pid INTEGER
     Set the first PID for elementary streams. Default is 0x0100, minimum is 0x0020, maximum is 0x1ffa. This option has no effect in m2ts mode where the elementary stream PIDs are fixed.

mpegts_m2ts_mode BOOLEAN
     Enable m2ts mode if set to 1. Default value is -1 which disables m2ts mode.

muxrate INTEGER
     Set a constant muxrate. Default is VBR.

pes_payload_size INTEGER
     Set minimum PES packet payload in bytes. Default is 2930.

mpegts_flags FLAGS
     Set mpegts flags. Accepts the following options:

     resend_headers
          Reemit PAT/PMT before writing the next packet.

     latm
          Use LATM packetization for AAC.

     pat_pmt_at_frames
          Reemit PAT and PMT at each video frame.

     system_b
          Conform to System B (DVB) instead of System A (ATSC).

     initial_discontinuity
          Mark the initial packet of each stream as discontinuity.

     nit
          Emit NIT table.

     omit_rai
          Disable writing of random access indicator.

mpegts_copyts BOOLEAN
     Preserve original timestamps, if value is set to 1. Default value is -1, which results in shifting timestamps so that they start from 0.

omit_video_pes_length BOOLEAN
     Omit the PES packet length for video packets. Default is 1 (true).

pcr_period INTEGER
     Override the default PCR retransmission time in milliseconds. Default is -1 which means that the PCR interval will be determined automatically: 20 ms is used for CBR streams, the highest multiple of the frame duration which is less than 100 ms is used for VBR streams.

pat_period DURATION
     Maximum time in seconds between PAT/PMT tables. Default is 0.1.

sdt_period DURATION
     Maximum time in seconds between SDT tables. Default is 0.5.

nit_period DURATION
     Maximum time in seconds between NIT tables. Default is 0.5.

tables_version INTEGER
     Set PAT, PMT, SDT and NIT version (default 0, valid values are from 0 to 31, inclusively). This option allows updating stream structure so that standard consumer may detect the change. To do so, reopen output AVFormatContext (in case of API usage) or restart ffmpeg instance, cyclically changing tables_version value:

          ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
          ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
          ...
          ffmpeg -i source3.ts -codec copy -f mpegts -tables_version 31 udp://1.1.1.1:1111
          ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
          ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
          ...

Example
-------

     ffmpeg -i file.mpg -c copy \
          -mpegts_original_network_id 0x1122 \
          -mpegts_transport_stream_id 0x3344 \
          -mpegts_service_id 0x5566 \
          -mpegts_pmt_start_pid 0x1500 \
          -mpegts_start_pid 0x150 \
          -metadata service_provider="Some provider" \
          -metadata service_name="Some Channel" \
          out.ts

mxf, mxf_d10, mxf_opatom
========================

MXF muxer.

Options
-------

The muxer options are:

store_user_comments BOOL
     Set if user comments should be stored if available or never. IRT D-10 does not allow user comments. The default is thus to write them for mxf and mxf_opatom but not for mxf_d10

null
====

Null muxer.

This muxer does not generate any output file, it is mainly useful for testing or benchmarking purposes.

For example to benchmark decoding with ffmpeg you can use the command:

     ffmpeg -benchmark -i INPUT -f null out.null

Note that the above command does not read or write the out.null file, but specifying the output file is required by the ffmpeg syntax.

Alternatively you can write the command as:

     ffmpeg -benchmark -i INPUT -f null -

nut
===

-syncpoints FLAGS
     Change the syncpoint usage in nut:

     DEFAULT use the normal low-overhead seeking aids.

     NONE do not use the syncpoints at all, reducing the overhead but making the stream non-seekable;
          Use of this option is not recommended, as the resulting files are very damage sensitive and seeking is not possible. Also in general the overhead from syncpoints is negligible. Note, -write_index 0 can be used to disable all growing data tables, allowing to mux endless streams with limited memory and without these disadvantages.

     TIMESTAMPED extend the syncpoint with a wallclock field.

     The NONE and TIMESTAMPED flags are experimental.

-write_index BOOL
     Write index at the end, the default is to write an index.

     ffmpeg -i INPUT -f_strict experimental -syncpoints none - | processor

ogg
===

Ogg container muxer.

-page_duration DURATION
     Preferred page duration, in microseconds. The muxer will attempt to create pages that are approximately DURATION microseconds long. This allows the user to compromise between seek granularity and container overhead. The default is 1 second. A value of 0 will fill all segments, making pages as large as possible. A value of 1 will effectively use 1 packet-per-page in most situations, giving a small seek granularity at the cost of additional container overhead.

-serial_offset VALUE
     Serial value from which to set the streams serial number. Setting it to different and sufficiently large values ensures that the produced ogg files can be safely chained.

rcwt
====

RCWT (Raw Captions With Time) is a format native to ccextractor, a commonly used open source tool for processing 608/708 Closed Captions (CC) sources. It can be used to archive the original extracted CC bitstream and to produce a source file for later processing or conversion. The format allows for interoperability between ccextractor and FFmpeg, is simple to parse, and can be used to create a backup of the CC presentation.

This muxer implements the specification as of March 2024, which has been stable and unchanged since April 2014.

This muxer will have some nuances from the way that ccextractor muxes RCWT. No compatibility issues when processing the output with ccextractor have been observed as a result of this so far, but mileage may vary and outputs will not be a bit-exact match.

A free specification of RCWT can be found here: https://github.com/CCExtractor/ccextractor/blob/master/docs/BINARY_FILE_FORMAT.TXT

Examples
--------

  * Extract Closed Captions to RCWT using lavfi:

          ffmpeg -f lavfi -i "movie=INPUT.mkv[out+subcc]" -map 0:s:0 -c:s copy -f rcwt CC.rcwt.bin

segment, stream_segment, ssegment
=================================

Basic stream segmenter.

This muxer outputs streams to a number of separate files of nearly fixed duration. Output filename pattern can be set in a fashion similar to image2, or by using a strftime template if the strftime option is enabled.

stream_segment is a variant of the muxer used to write to streaming output formats, i.e. which do not require global headers, and is recommended for outputting e.g. to MPEG transport stream segments. ssegment is a shorter alias for stream_segment.

Every segment starts with a keyframe of the selected reference stream, which is set through the reference_stream option.

Note that if you want accurate splitting for a video file, you need to make the input key frames correspond to the exact splitting times expected by the segmenter, or the segment muxer will start the new segment with the key frame found next after the specified start time.

The segment muxer works best with a single constant frame rate video.

Optionally it can generate a list of the created segments, by setting the option SEGMENT_LIST. The list type is specified by the SEGMENT_LIST_TYPE option. The entry filenames in the segment list are set by default to the basename of the corresponding segment files.

See also the hls muxer, which provides a more specific implementation for HLS segmentation.

Options
-------

The segment muxer supports the following options:

increment_tc 1|0
     if set to 1, increment timecode between each segment If this is selected, the input need to have a timecode in the first video stream. Default value is 0.

reference_stream SPECIFIER
     Set the reference stream, as specified by the string SPECIFIER. If SPECIFIER is set to auto, the reference is chosen automatically. Otherwise it must be a stream specifier (see the ``Stream specifiers'' chapter in the ffmpeg manual) which specifies the reference stream. The default value is auto.

segment_format FORMAT
     Override the inner container format, by default it is guessed by the filename extension.

segment_format_options OPTIONS_LIST
     Set output format options using a :-separated list of key=value parameters. Values containing the : special character must be escaped.

segment_list NAME
     Generate also a listfile named NAME. If not specified no listfile is generated.

segment_list_flags FLAGS
     Set flags affecting the segment list generation.

     It currently supports the following flags:

     cache
          Allow caching (only affects M3U8 list files).

     live
          Allow live-friendly file generation.

segment_list_size SIZE
     Update the list file so that it contains at most SIZE segments. If 0 the list file will contain all the segments. Default value is 0.

segment_list_entry_prefix PREFIX
     Prepend PREFIX to each entry. Useful to generate absolute paths. By default no prefix is applied.

segment_list_type TYPE
     Select the listing format.

     The following values are recognized:

     flat
          Generate a flat list for the created segments, one segment per line.

     csv, ext
          Generate a list for the created segments, one segment per line, each line matching the format (comma-separated values):

               SEGMENT_FILENAME,SEGMENT_START_TIME,SEGMENT_END_TIME

          SEGMENT_FILENAME is the name of the output file generated by the muxer according to the provided pattern. CSV escaping (according to RFC4180) is applied if required.

          SEGMENT_START_TIME and SEGMENT_END_TIME specify the segment start and end time expressed in seconds.

          A list file with the suffix ".csv" or ".ext" will auto-select this format.

          ext is deprecated in favor or csv.

     ffconcat
          Generate an ffconcat file for the created segments. The resulting file can be read using the FFmpeg concat demuxer.

          A list file with the suffix ".ffcat" or ".ffconcat" will auto-select this format.

     m3u8
          Generate an extended M3U8 file, version 3, compliant with http://tools.ietf.org/id/draft-pantos-http-live-streaming.

          A list file with the suffix ".m3u8" will auto-select this format.

     If not specified the type is guessed from the list file name suffix.

segment_time TIME
     Set segment duration to TIME, the value must be a duration specification. Default value is "2". See also the segment_times option.

     Note that splitting may not be accurate, unless you force the reference stream key-frames at the given time. See the introductory notice and the examples below.

min_seg_duration TIME
     Set minimum segment duration to TIME, the value must be a duration specification. This prevents the muxer ending segments at a duration below this value. Only effective with segment_time. Default value is "0".

segment_atclocktime 1|0
     If set to "1" split at regular clock time intervals starting from 00:00 o'clock. The TIME value specified in segment_time is used for setting the length of the splitting interval.

     For example with segment_time set to "900" this makes it possible to create files at 12:00 o'clock, 12:15, 12:30, etc.

     Default value is "0".

segment_clocktime_offset DURATION
     Delay the segment splitting times with the specified duration when using segment_atclocktime.

     For example with segment_time set to "900" and segment_clocktime_offset set to "300" this makes it possible to create files at 12:05, 12:20, 12:35, etc.

     Default value is "0".

segment_clocktime_wrap_duration DURATION
     Force the segmenter to only start a new segment if a packet reaches the muxer within the specified duration after the segmenting clock time. This way you can make the segmenter more resilient to backward local time jumps, such as leap seconds or transition to standard time from daylight savings time.

     Default is the maximum possible duration which means starting a new segment regardless of the elapsed time since the last clock time.

segment_time_delta DELTA
     Specify the accuracy time when selecting the start time for a segment, expressed as a duration specification. Default value is "0".

     When delta is specified a key-frame will start a new segment if its PTS satisfies the relation:

          PTS >= start_time - time_delta

     This option is useful when splitting video content, which is always split at GOP boundaries, in case a key frame is found just before the specified split time.

     In particular may be used in combination with the ffmpeg option FORCE_KEY_FRAMES. The key frame times specified by FORCE_KEY_FRAMES may not be set accurately because of rounding issues, with the consequence that a key frame time may result set just before the specified time. For constant frame rate videos a value of 1/(2*FRAME_RATE) should address the worst case mismatch between the specified time and the time set by FORCE_KEY_FRAMES.

segment_times TIMES
     Specify a list of split points. TIMES contains a list of comma separated duration specifications, in increasing order. See also the segment_time option.

segment_frames FRAMES
     Specify a list of split video frame numbers. FRAMES contains a list of comma separated integer numbers, in increasing order.

     This option specifies to start a new segment whenever a reference stream key frame is found and the sequential number (starting from 0) of the frame is greater or equal to the next value in the list.

segment_wrap LIMIT
     Wrap around segment index once it reaches LIMIT.

segment_start_number NUMBER
     Set the sequence number of the first segment. Defaults to 0.

strftime 1|0
     Use the strftime function to define the name of the new segments to write. If this is selected, the output segment name must contain a strftime function template. Default value is 0.

break_non_keyframes 1|0
     If enabled, allow segments to start on frames other than keyframes. This improves behavior on some players when the time between keyframes is inconsistent, but may make things worse on others, and can cause some oddities during seeking. Defaults to 0.

reset_timestamps 1|0
     Reset timestamps at the beginning of each segment, so that each segment will start with near-zero timestamps. It is meant to ease the playback of the generated segments. May not work with some combinations of muxers/codecs. It is set to 0 by default.

initial_offset OFFSET
     Specify timestamp offset to apply to the output packet timestamps. The argument must be a time duration specification, and defaults to 0.

write_empty_segments 1|0
     If enabled, write an empty segment if there are no packets during the period a segment would usually span. Otherwise, the segment will be filled with the next packet written. Defaults to 0.

Make sure to require a closed GOP when encoding and to set the GOP size to fit your segment time constraint.

Examples
--------

  * Remux the content of file in.mkv to a list of segments out-000.nut, out-001.nut, etc., and write the list of generated segments to out.list:

          ffmpeg -i in.mkv -codec hevc -flags +cgop -g 60 -map 0 -f segment -segment_list out.list out%03d.nut

  * Segment input and set output format options for the output segments:

          ffmpeg -i in.mkv -f segment -segment_time 10 -segment_format_options movflags=+faststart out%03d.mp4

  * Segment the input file according to the split points specified by the SEGMENT_TIMES option:

          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

  * Use the ffmpeg force_key_frames option to force key frames in the input at the specified location, together with the segment option segment_time_delta to account for possible roundings operated when setting key frame times.

          ffmpeg -i in.mkv -force_key_frames 1,2,3,5,8,13,21 -codec:v mpeg4 -codec:a pcm_s16le -map 0 \
          -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 -segment_time_delta 0.05 out%03d.nut

     In order to force key frames on the input file, transcoding is required.

  * Segment the input file by splitting the input file according to the frame numbers sequence specified with the segment_frames option:

          ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_frames 100,200,300,500,800 out%03d.nut

  * Convert the in.mkv to TS segments using the libx264 and aac encoders:

          ffmpeg -i in.mkv -map 0 -codec:v libx264 -codec:a aac -f ssegment -segment_list out.list out%03d.ts

  * Segment the input file, and create an M3U8 live playlist (can be used as live HLS source):

          ffmpeg -re -i in.mkv -codec copy -map 0 -f segment -segment_list playlist.m3u8 \
          -segment_list_flags +live -segment_time 10 out%03d.mkv

smoothstreaming
===============

Smooth Streaming muxer generates a set of files (Manifest, chunks) suitable for serving with conventional web server.

window_size
     Specify the number of fragments kept in the manifest. Default 0 (keep all).

extra_window_size
     Specify the number of fragments kept outside of the manifest before removing from disk. Default 5.

lookahead_count
     Specify the number of lookahead fragments. Default 2.

min_frag_duration
     Specify the minimum fragment duration (in microseconds). Default 5000000.

remove_at_exit
     Specify whether to remove all fragments when finished. Default 0 (do not remove).

streamhash
==========

Per stream hash testing format.

This muxer computes and prints a cryptographic hash of all the input frames, on a per-stream basis. This can be used for equality checks without having to do a complete binary comparison.

By default audio frames are converted to signed 16-bit raw audio and video frames to raw video before computing the hash, but the output of explicit conversions to other codecs can also be used. Timestamps are ignored. It uses the SHA-256 cryptographic hash function by default, but supports several other algorithms.

The output of the muxer consists of one line per stream of the form: STREAMINDEX,STREAMTYPE,ALGO=HASH, where STREAMINDEX is the index of the mapped stream, STREAMTYPE is a single character indicating the type of stream, ALGO is a short string representing the hash function used, and HASH is a hexadecimal number representing the computed hash.

hash ALGORITHM
     Use the cryptographic hash function specified by the string ALGORITHM. Supported values include MD5, murmur3, RIPEMD128, RIPEMD160, RIPEMD256, RIPEMD320, SHA160, SHA224, SHA256 (default), SHA512/224, SHA512/256, SHA384, SHA512, CRC32 and adler32.

Examples
--------

To compute the SHA-256 hash of the input converted to raw audio and video, and store it in the file out.sha256:

     ffmpeg -i INPUT -f streamhash out.sha256

To print an MD5 hash to stdout use the command:

     ffmpeg -i INPUT -f streamhash -hash md5 -

See also the hash and framehash muxers.

tee
===

The tee muxer can be used to write the same data to several outputs, such as files or streams. It can be used, for example, to stream a video over a network and save it to disk at the same time.

It is different from specifying several outputs to the ffmpeg command-line tool. With the tee muxer, the audio and video data will be encoded only once. With conventional multiple outputs, multiple encoding operations in parallel are initiated, which can be a very expensive process. The tee muxer is not useful when using the libavformat API directly because it is then possible to feed the same packets to several muxers directly.

Since the tee muxer does not represent any particular output format, ffmpeg cannot auto-select output streams. So all streams intended for output must be specified using -map. See the examples below.

Some encoders may need different options depending on the output format; the auto-detection of this can not work with the tee muxer, so they need to be explicitly specified. The main example is the global_header flag.

The slave outputs are specified in the file name given to the muxer, separated by '|'. If any of the slave name contains the '|' separator, leading or trailing spaces or any special character, those must be escaped (see the "Quoting and escaping" section in the ffmpeg-utils(1) manual (ffmpeg-utils)).

Options
-------

use_fifo BOOL
     If set to 1, slave outputs will be processed in separate threads using the fifo muxer. This allows to compensate for different speed/latency/reliability of outputs and setup transparent recovery. By default this feature is turned off.

fifo_options
     Options to pass to fifo pseudo-muxer instances. See fifo.

Muxer options can be specified for each slave by prepending them as a list of KEY=VALUE pairs separated by ':', between square brackets. If the options values contain a special character or the ':' separator, they must be escaped; note that this is a second level escaping.

The following special options are also recognized:

f
     Specify the format name. Required if it cannot be guessed from the output URL.

bsfs[/SPEC]
     Specify a list of bitstream filters to apply to the specified output.

     It is possible to specify to which streams a given bitstream filter applies, by appending a stream specifier to the option separated by /. SPEC must be a stream specifier (see Format stream specifiers).

     If the stream specifier is not specified, the bitstream filters will be applied to all streams in the output. This will cause that output operation to fail if the output contains streams to which the bitstream filter cannot be applied e.g. h264_mp4toannexb being applied to an output containing an audio stream.

     Options for a bitstream filter must be specified in the form of opt=value.

     Several bitstream filters can be specified, separated by ",".

use_fifo BOOL
     This allows to override tee muxer use_fifo option for individual slave muxer.

fifo_options
     This allows to override tee muxer fifo_options for individual slave muxer. See fifo.

select
     Select the streams that should be mapped to the slave output, specified by a stream specifier. If not specified, this defaults to all the mapped streams. This will cause that output operation to fail if the output format does not accept all mapped streams.

     You may use multiple stream specifiers separated by commas (,) e.g.: a:0,v

onfail
     Specify behaviour on output failure. This can be set to either abort (which is default) or ignore. abort will cause whole process to fail in case of failure on this slave output. ignore will ignore failure on this output, so other outputs will continue without being affected.

Examples
--------

  * Encode something and both archive it in a WebM file and stream it as MPEG-TS over UDP:

          ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
            "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"

  * As above, but continue streaming even if output to local file fails (for example local drive fills up):

          ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
            "[onfail=ignore]archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"

  * Use ffmpeg to encode the input, and send the output to three different destinations. The dump_extra bitstream filter is used to add extradata information to all the output video keyframes packets, as requested by the MPEG-TS format. The select option is applied to out.aac in order to make it contain only audio packets.

          ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
                 -f tee "[bsfs/v=dump_extra=freq=keyframe]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac"

  * As above, but select only stream a:1 for the audio output. Note that a second level escaping must be performed, as ":" is a special character used to separate options.

          ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
                 -f tee "[bsfs/v=dump_extra=freq=keyframe]out.ts|[movflags=+faststart]out.mp4|[select=\'a:1\']out.aac"

webm_chunk
==========

WebM Live Chunk Muxer.

This muxer writes out WebM headers and chunks as separate files which can be consumed by clients that support WebM Live streams via DASH.

Options
-------

This muxer supports the following options:

chunk_start_index
     Index of the first chunk (defaults to 0).

header
     Filename of the header where the initialization data will be written.

audio_chunk_duration
     Duration of each audio chunk in milliseconds (defaults to 5000).

Example
-------

     ffmpeg -f v4l2 -i /dev/video0 \
            -f alsa -i hw:0 \
            -map 0:0 \
            -c:v libvpx-vp9 \
            -s 640x360 -keyint_min 30 -g 30 \
            -f webm_chunk \
            -header webm_live_video_360.hdr \
            -chunk_start_index 1 \
            webm_live_video_360_%d.chk \
            -map 1:0 \
            -c:a libvorbis \
            -b:a 128k \
            -f webm_chunk \
            -header webm_live_audio_128.hdr \
            -chunk_start_index 1 \
            -audio_chunk_duration 1000 \
            webm_live_audio_128_%d.chk

webm_dash_manifest
==================

WebM DASH Manifest muxer.

This muxer implements the WebM DASH Manifest specification to generate the DASH manifest XML. It also supports manifest generation for DASH live streams.

For more information see:

  * WebM DASH Specification: https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification

  * ISO DASH Specification: http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip

Options
-------

This muxer supports the following options:

adaptation_sets
     This option has the following syntax: "id=x,streams=a,b,c id=y,streams=d,e" where x and y are the unique identifiers of the adaptation sets and a,b,c,d and e are the indices of the corresponding audio and video streams. Any number of adaptation sets can be added using this option.

live
     Set this to 1 to create a live stream DASH Manifest. Default: 0.

chunk_start_index
     Start index of the first chunk. This will go in the startNumber attribute of the SegmentTemplate element in the manifest. Default: 0.

chunk_duration_ms
     Duration of each chunk in milliseconds. This will go in the duration attribute of the SegmentTemplate element in the manifest. Default: 1000.

utc_timing_url
     URL of the page that will return the UTC timestamp in ISO format. This will go in the value attribute of the UTCTiming element in the manifest. Default: None.

time_shift_buffer_depth
     Smallest time (in seconds) shifting buffer for which any Representation is guaranteed to be available. This will go in the timeShiftBufferDepth attribute of the MPD element. Default: 60.

minimum_update_period
     Minimum update period (in seconds) of the manifest. This will go in the minimumUpdatePeriod attribute of the MPD element. Default: 0.

Example
-------

     ffmpeg -f webm_dash_manifest -i video1.webm \
            -f webm_dash_manifest -i video2.webm \
            -f webm_dash_manifest -i audio1.webm \
            -f webm_dash_manifest -i audio2.webm \
            -map 0 -map 1 -map 2 -map 3 \
            -c copy \
            -f webm_dash_manifest \
            -adaptation_sets "id=0,streams=0,1 id=1,streams=2,3" \
            manifest.xml

whip
====

WebRTC (Real-Time Communication) muxer that supports sub-second latency streaming according to the WHIP (WebRTC-HTTP ingestion protocol) specification.

This is an experimental feature.

It uses HTTP as a signaling protocol to exchange SDP capabilities and ICE lite candidates. Then, it uses STUN binding requests and responses to establish a session over UDP. Subsequently, it initiates a DTLS handshake to exchange the SRTP encryption keys. Lastly, it splits video and audio frames into RTP packets and encrypts them using SRTP.

Ensure that you use H.264 without B frames and Opus for the audio codec. For example, to convert an input file with ffmpeg to WebRTC:

     ffmpeg -re -i input.mp4 -acodec libopus -ar 48000 -ac 2 \
       -vcodec libx264 -profile:v baseline -tune zerolatency -threads 1 -bf 0 \
       -f whip "http://localhost:1985/rtc/v1/whip/?app=live&stream=livestream"

For this example, we have employed low latency options, resulting in an end-to-end latency of approximately 150ms.

Options
-------

This muxer supports the following options:

handshake_timeout INTEGER
     Set the timeout in milliseconds for ICE and DTLS handshake. Default value is 5000.

timeout INTEGER
     Set timeout in seconds for socket I/O operations. Applicable only for HTTP output. Default value is -1.

pkt_size INTEGER
     Set the maximum size, in bytes, of RTP packets that send out. Default value is 1200.

ts_buffer_size INTEGER
     Set the buffer size, in bytes, of underlying protocol. Default value is -1(auto). The UDP auto selects a reasonable value.

whip_flags FLAGS
     Possible values:

     dtls_active
          The muxer will try to set dtls active role and send the first client hello.

rtp_history INTEGER
     Set the number of RTP history items to store. Default value is 512.

authorization STRING
     The optional Bearer token for WHIP Authorization.

cert_file STRING
     The optional certificate file path for DTLS.

key_file STRING
     The optional private key file path for DTLS.