ffmpeg-formats - FFmpeg formats

Authors

       The FFmpeg developers.

       For  details  about  the  authorship, see the Git history of the project (https://git.ffmpeg.org/ffmpeg),
       e.g. by typing the command gitlog in the FFmpeg source directory, or browsing the online  repository  at
       <https://git.ffmpeg.org/ffmpeg>.

       Maintainers for the specific components are listed in the file MAINTAINERS in the source code tree.

                                                                                               FFMPEG-FORMATS(1)

Demuxers

Demuxers are configured elements in FFmpeg that can read the multimedia streams from a particular type of
file.

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

You can disable all the demuxers using the configure option "--disable-demuxers", and selectively enable
a single demuxer with the option "--enable-demuxer=DEMUXER", or disable it with the option
"--disable-demuxer=DEMUXER".

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

The description of some of the currently available demuxers follows.

aa
Audible Format 2, 3, and 4 demuxer.

This demuxer is used to demux Audible Format 2, 3, and 4 (.aa) files.

aac
Raw Audio Data Transport Stream AAC demuxer.

This demuxer is used to demux an ADTS input containing a single AAC stream alongwith any ID3v1/2 or APE
tags in it.

apng
Animated Portable Network Graphics demuxer.

This demuxer is used to demux APNG files. All headers, but the PNG signature, up to (but not including)
the first fcTL chunk are transmitted as extradata. Frames are then split as being all the chunks between
two fcTL ones, or between the last fcTL and IEND chunks.

-ignore_loopbool
Ignore the loop variable in the file if set. Default is enabled.

-max_fpsint
Maximum framerate in frames per second. Default of 0 imposes no limit.

-default_fpsint
Default framerate in frames per second when none is specified in the file (0 meaning as fast as
possible). Default is 15.

asf
Advanced Systems Format demuxer.

This demuxer is used to demux ASF files and MMS network streams.

-no_resync_searchbool
Do not try to resynchronize by looking for a certain optional start code.

concat
Virtual concatenation script demuxer.

This demuxer reads a list of files and other directives from a text file and demuxes them one after the
other, as if all their packets had been muxed together.

The timestamps in the files are adjusted so that the first file starts at 0 and each next file starts
where the previous one finishes. Note that it is done globally and may cause gaps if all streams do not
have exactly the same length.

All files must have the same streams (same codecs, same time base, etc.).

The duration of each file is used to adjust the timestamps of the next file: if the duration is incorrect
(because it was computed using the bit-rate or because the file is truncated, for example), it can cause
artifacts. The "duration" directive can be used to override the duration stored in each file.

Syntax

The script is a text file in extended-ASCII, with one directive per line. Empty lines, leading spaces
and lines starting with '#' are ignored. The following directive is recognized:

"filepath"
Path to a file to read; special characters and spaces must be escaped with backslash or single
quotes.

All subsequent file-related directives apply to that file.

"ffconcatversion1.0"
Identify the script type and version.

To make FFmpeg recognize the format automatically, this directive must appear exactly as is (no extra
space or byte-order-mark) on the very first line of the script.

"durationdur"
Duration of the file. This information can be specified from the file; specifying it here may be more
efficient or help if the information from the file is not available or accurate.

If the duration is set for all files, then it is possible to seek in the whole concatenated video.

"inpointtimestamp"
In point of the file. When the demuxer opens the file it instantly seeks to the specified timestamp.
Seeking is done so that all streams can be presented successfully at In point.

This directive works best with intra frame codecs, because for non-intra frame ones you will usually
get extra packets before the actual In point and the decoded content will most likely contain frames
before In point too.

For each file, packets before the file In point will have timestamps less than the calculated start
timestamp of the file (negative in case of the first file), and the duration of the files (if not
specified by the "duration" directive) will be reduced based on their specified In point.

Because of potential packets before the specified In point, packet timestamps may overlap between two
concatenated files.

"outpointtimestamp"
Out point of the file. When the demuxer reaches the specified decoding timestamp in any of the
streams, it handles it as an end of file condition and skips the current and all the remaining
packets from all streams.

Out point is exclusive, which means that the demuxer will not output packets with a decoding
timestamp greater or equal to Out point.

This directive works best with intra frame codecs and formats where all streams are tightly
interleaved. For non-intra frame codecs you will usually get additional packets with presentation
timestamp after Out point therefore the decoded content will most likely contain frames after Out
point too. If your streams are not tightly interleaved you may not get all the packets from all
streams before Out point and you may only will be able to decode the earliest stream until Out point.

The duration of the files (if not specified by the "duration" directive) will be reduced based on
their specified Out point.

"file_packet_metadatakey=value"
Metadata of the packets of the file. The specified metadata will be set for each file packet. You can
specify this directive multiple times to add multiple metadata entries. This directive is
deprecated, use "file_packet_meta" instead.

"file_packet_metakeyvalue"
Metadata of the packets of the file. The specified metadata will be set for each file packet. You can
specify this directive multiple times to add multiple metadata entries.

"optionkeyvalue"
Option to access, open and probe the file. Can be present multiple times.

"stream"
Introduce a stream in the virtual file. All subsequent stream-related directives apply to the last
introduced stream. Some streams properties must be set in order to allow identifying the matching
streams in the subfiles. If no streams are defined in the script, the streams from the first file
are copied.

"exact_stream_idid"
Set the id of the stream. If this directive is given, the string with the corresponding id in the
subfiles will be used. This is especially useful for MPEG-PS (VOB) files, where the order of the
streams is not reliable.

"stream_metakeyvalue"
Metadata for the stream. Can be present multiple times.

"stream_codecvalue"
Codec for the stream.

"stream_extradatahex_string"
Extradata for the string, encoded in hexadecimal.

"chapteridstartend"
Add a chapter. id is an unique identifier, possibly small and consecutive.

Options

This demuxer accepts the following option:

safe
If set to 1, reject unsafe file paths and directives. A file path is considered safe if it does not
contain a protocol specification and is relative and all components only contain characters from the
portable character set (letters, digits, period, underscore and hyphen) and have no period at the
beginning of a component.

If set to 0, any file name is accepted.

The default is 1.

auto_convert
If set to 1, try to perform automatic conversions on packet data to make the streams concatenable.
The default is 1.

Currently, the only conversion is adding the h264_mp4toannexb bitstream filter to H.264 streams in
MP4 format. This is necessary in particular if there are resolution changes.

segment_time_metadata
If set to 1, every packet will contain the lavf.concat.start_time and the lavf.concat.duration packet
metadata values which are the start_time and the duration of the respective file segments in the
concatenated output expressed in microseconds. The duration metadata is only set if it is known based
on the concat file. The default is 0.

Examples

• Use absolute filenames and include some comments:

# my first filename
file /mnt/share/file-1.wav
# my second filename including whitespace
file '/mnt/share/file 2.wav'
# my third filename including whitespace plus single quote
file '/mnt/share/file 3'\''.wav'

• Allow for input format auto-probing, use safe filenames and set the duration of the first file:

ffconcat version 1.0

file file-1.wav
duration 20.0

file subdir/file-2.wav

dash
Dynamic Adaptive Streaming over HTTP demuxer.

This demuxer presents all AVStreams found in the manifest. By setting the discard flags on AVStreams the
caller can decide which streams to actually receive. Each stream mirrors the "id" and "bandwidth"
properties from the "<Representation>" as metadata keys named "id" and "variant_bitrate" respectively.

Options

This demuxer accepts the following option:

cenc_decryption_key
16-byte key, in hex, to decrypt files encrypted using ISO Common Encryption (CENC/AES-128 CTR;
ISO/IEC 23001-7).

dvdvideo
DVD-Video demuxer, powered by libdvdnav and libdvdread.

Can directly ingest DVD titles, specifically sequential PGCs, into a conversion pipeline. Menu assets,
such as background video or audio, can also be demuxed given the menu's coordinates (at best effort).

Block devices (DVD drives), ISO files, and directory structures are accepted. Activate with "-f
dvdvideo" in front of one of these inputs.

This demuxer does NOT have decryption code of any kind. You are on your own working with encrypted DVDs,
and should not expect support on the matter.

Underlying playback is handled by libdvdnav, and structure parsing by libdvdread. FFmpeg must be built
with GPL library support available as well as the configure switches "--enable-libdvdnav" and
"--enable-libdvdread".

You will need to provide either the desired "title number" or exact PGC/PG coordinates. Many open-source
DVD players and tools can aid in providing this information. If not specified, the demuxer will default
to title 1 which works for many discs. However, due to the flexibility of the format, it is recommended
to check manually. There are many discs that are authored strangely or with invalid headers.

If the input is a real DVD drive, please note that there are some drives which may silently fail on
reading bad sectors from the disc, returning random bits instead which is effectively corrupt data. This
is especially prominent on aging or rotting discs. A second pass and integrity checks would be needed to
detect the corruption. This is not an FFmpeg issue.

Background

DVD-Video is not a directly accessible, linear container format in the traditional sense. Instead, it
allows for complex and programmatic playback of carefully muxed MPEG-PS streams that are stored in
headerless VOB files. To the end-user, these streams are known simply as "titles", but the actual
logical playback sequence is defined by one or more "PGCs", or Program Group Chains, within the title.
The PGC is in turn comprised of multiple "PGs", or Programs", which are the actual video segments (and
for a typical video feature, sequentially ordered). The PGC structure, along with stream layout and
metadata, are stored in IFO files that need to be parsed. PGCs can be thought of as playlists in easier
terms.

An actual DVD player relies on user GUI interaction via menus and an internal VM to drive the direction
of demuxing. Generally, the user would either navigate (via menus) or automatically be redirected to the
PGC of their choice. During this process and the subsequent playback, the DVD player's internal VM also
maintains a state and executes instructions that can create jumps to different sectors during playback.
This is why libdvdnav is involved, as a linear read of the MPEG-PS blobs on the disc (VOBs) is not enough
to produce the right sequence in many cases.

There are many other DVD structures (a long subject) that will not be discussed here. NAV packets, in
particular, are handled by this demuxer to build accurate timing but not emitted as a stream. For a good
high-level understanding, refer to:
<https://code.videolan.org/videolan/libdvdnav/-/blob/master/doc/dvd_structures>

Options

This demuxer accepts the following options:

titleint
The title number to play. Must be set if pgc and pg are not set. Not applicable to menus. Default
is 0 (auto), which currently only selects the first available title (title 1) and notifies the user
about the implications.

chapter_startint
The chapter, or PTT (part-of-title), number to start at. Not applicable to menus. Default is 1.

chapter_endint
The chapter, or PTT (part-of-title), number to end at. Not applicable to menus. Default is 0, which
is a special value to signal end at the last possible chapter.

angleint
The video angle number, referring to what is essentially an additional video stream that is composed
from alternate frames interleaved in the VOBs. Not applicable to menus. Default is 1.

regionint
The region code to use for playback. Some discs may use this to default playback at a particular
angle in different regions. This option will not affect the region code of a real DVD drive, if used
as an input. Not applicable to menus. Default is 0, "world".

menubool
Demux menu assets instead of navigating a title. Requires exact coordinates of the menu (menu_lu,
menu_vts, pgc, pg). Default is false.

menu_luint
The menu language to demux. In DVD, menus are grouped by language. Default is 1, the first language
unit.

menu_vtsint
The VTS where the menu lives, or 0 if it is a VMG menu (root-level). Default is 1, menu of the first
VTS.

pgcint
The entry PGC to start playback, in conjunction with pg. Alternative to setting title. Chapter
markers are not supported at this time. Must be explicitly set for menus. Default is 0,
automatically resolve from value of title.

pgint
The entry PG to start playback, in conjunction with pgc. Alternative to setting title. Chapter
markers are not supported at this time. Default is 1, the first PG of the PGC.

preindexbool
Enable this to have accurate chapter (PTT) markers and duration measurement, which requires a slow
second pass read in order to index the chapter marker timestamps from NAV packets. This is non-ideal
extra work for real optical drives. It is recommended and faster to use this option with a backup of
the DVD structure stored on a hard drive. Not compatible with pgc and pg. Default is 0, false.

trimbool
Skip padding cells (i.e. cells shorter than 1 second) from the beginning. There exist many discs
with filler segments at the beginning of the PGC, often with junk data intended for controlling a
real DVD player's buffering speed and with no other material data value. Not applicable to menus.
Default is 1, true.

Examples

• Open title 3 from a given DVD structure:

ffmpeg -f dvdvideo -title 3 -i <path to DVD> ...

• Open chapters 3-6 from title 1 from a given DVD structure:

ffmpeg -f dvdvideo -chapter_start 3 -chapter_end 6 -title 1 -i <path to DVD> ...

• Open only chapter 5 from title 1 from a given DVD structure:

ffmpeg -f dvdvideo -chapter_start 5 -chapter_end 5 -title 1 -i <path to DVD> ...

• Demux menu with language 1 from VTS 1, PGC 1, starting at PG 1:

ffmpeg -f dvdvideo -menu 1 -menu_lu 1 -menu_vts 1 -pgc 1 -pg 1 -i <path to DVD> ...

ea
Electronic Arts Multimedia format demuxer.

This format is used by various Electronic Arts games.

Optionsmerge_alphabool
Normally the VP6 alpha channel (if exists) is returned as a secondary video stream, by setting this
option you can make the demuxer return a single video stream which contains the alpha channel in
addition to the ordinary video.

imf
Interoperable Master Format demuxer.

This demuxer presents audio and video streams found in an IMF Composition, as specified in
<https://doi.org/10.5594/SMPTE.ST2067-2.2020>.

ffmpeg [-assetmaps <path of ASSETMAP1>,<path of ASSETMAP2>,...] -i <path of CPL> ...

If "-assetmaps" is not specified, the demuxer looks for a file called ASSETMAP.xml in the same directory
as the CPL.

flv,live_flv,kux
Adobe Flash Video Format demuxer.

This demuxer is used to demux FLV files and RTMP network streams. In case of live network streams, if you
force format, you may use live_flv option instead of flv to survive timestamp discontinuities. KUX is a
flv variant used on the Youku platform.

ffmpeg -f flv -i myfile.flv ...
ffmpeg -f live_flv -i rtmp://<any.server>/anything/key ....

-flv_metadatabool
Allocate the streams according to the onMetaData array content.

-flv_ignore_prevtagbool
Ignore the size of previous tag value.

-flv_full_metadatabool
Output all context of the onMetadata.

gif
Animated GIF demuxer.

It accepts the following options:

min_delay
Set the minimum valid delay between frames in hundredths of seconds. Range is 0 to 6000. Default
value is 2.

max_gif_delay
Set the maximum valid delay between frames in hundredth of seconds. Range is 0 to 65535. Default
value is 65535 (nearly eleven minutes), the maximum value allowed by the specification.

default_delay
Set the default delay between frames in hundredths of seconds. Range is 0 to 6000. Default value is
10.

ignore_loop
GIF files can contain information to loop a certain number of times (or infinitely). If ignore_loop
is set to 1, then the loop setting from the input will be ignored and looping will not occur. If set
to 0, then looping will occur and will cycle the number of times according to the GIF. Default value
is 1.

For example, with the overlay filter, place an infinitely looping GIF over another video:

ffmpeg -i input.mp4 -ignore_loop 0 -i input.gif -filter_complex overlay=shortest=1 out.mkv

Note that in the above example the shortest option for overlay filter is used to end the output video at
the length of the shortest input file, which in this case is input.mp4 as the GIF in this example loops
infinitely.

hls
HLS demuxer

Apple HTTP Live Streaming demuxer.

This demuxer presents all AVStreams from all variant streams. The id field is set to the bitrate variant
index number. By setting the discard flags on AVStreams (by pressing 'a' or 'v' in ffplay), the caller
can decide which variant streams to actually receive. The total bitrate of the variant that the stream
belongs to is available in a metadata key named "variant_bitrate".

It accepts the following options:

live_start_index
segment index to start live streams at (negative values are from the end).

prefer_x_start
prefer to use #EXT-X-START if it's in playlist instead of live_start_index.

allowed_extensions
',' separated list of file extensions that hls is allowed to access.

extension_picky
This blocks disallowed extensions from probing It also requires all available segments to have
matching extensions to the format except mpegts, which is always allowed. It is recommended to set
the whitelists correctly instead of depending on extensions Enabled by default.

max_reload
Maximum number of times a insufficient list is attempted to be reloaded. Default value is 1000.

m3u8_hold_counters
The maximum number of times to load m3u8 when it refreshes without new segments. Default value is
1000.

http_persistent
Use persistent HTTP connections. Applicable only for HTTP streams. Enabled by default.

http_multiple
Use multiple HTTP connections for downloading HTTP segments. Enabled by default for HTTP/1.1
servers.

http_seekable
Use HTTP partial requests for downloading HTTP segments. 0 = disable, 1 = enable, -1 = auto, Default
is auto.

seg_format_options
Set options for the demuxer of media segments using a list of key=value pairs separated by ":".

seg_max_retry
Maximum number of times to reload a segment on error, useful when segment skip on network error is
not desired. Default value is 0.

image2
Image file demuxer.

This demuxer reads from a list of image files specified by a pattern. The syntax and meaning of the
pattern is specified by the option pattern_type.

The pattern may contain a suffix which is used to automatically determine the format of the images
contained in the files.

The size, the pixel format, and the format of each image must be the same for all the files in the
sequence.

This demuxer accepts the following options:

framerate
Set the frame rate for the video stream. It defaults to 25.

loop
If set to 1, loop over the input. Default value is 0.

pattern_type
Select the pattern type used to interpret the provided filename.

pattern_type accepts one of the following values.

none
Disable pattern matching, therefore the video will only contain the specified image. You should
use this option if you do not want to create sequences from multiple images and your filenames
may contain special pattern characters.

sequence
Select a sequence pattern type, used to specify a sequence of files indexed by sequential
numbers.

A sequence pattern may contain the string "%d" or "%0Nd", which specifies the position of the
characters representing a sequential number in each filename matched by the pattern. If the form
"%d0Nd" is used, the string representing the number in each filename is 0-padded and N is the
total number of 0-padded digits representing the number. The literal character '%' can be
specified in the pattern with the string "%%".

If the sequence pattern contains "%d" or "%0Nd", the first filename of the file list specified by
the pattern must contain a number inclusively contained between start_number and
start_number+start_number_range-1, and all the following numbers must be sequential.

For example the pattern "img-%03d.bmp" will match a sequence of filenames of the form
img-001.bmp, img-002.bmp, ..., img-010.bmp, etc.; the pattern "i%%m%%g-%d.jpg" will match a
sequence of filenames of the form i%m%g-1.jpg, i%m%g-2.jpg, ..., i%m%g-10.jpg, etc.

Note that the pattern must not necessarily contain "%d" or "%0Nd", for example to convert a
single image file img.jpeg you can employ the command:

ffmpeg -i img.jpeg img.png

glob
Select a glob wildcard pattern type.

The pattern is interpreted like a glob() pattern. This is only selectable if libavformat was
compiled with globbing support.

glob_sequence(deprecated,willberemoved)
Select a mixed glob wildcard/sequence pattern.

If your version of libavformat was compiled with globbing support, and the provided pattern
contains at least one glob meta character among "%*?[]{}" that is preceded by an unescaped "%",
the pattern is interpreted like a glob() pattern, otherwise it is interpreted like a sequence
pattern.

All glob special characters "%*?[]{}" must be prefixed with "%". To escape a literal "%" you
shall use "%%".

For example the pattern "foo-%*.jpeg" will match all the filenames prefixed by "foo-" and
terminating with ".jpeg", and "foo-%?%?%?.jpeg" will match all the filenames prefixed with
"foo-", followed by a sequence of three characters, and terminating with ".jpeg".

This pattern type is deprecated in favor of glob and sequence.

Default value is glob_sequence.

pixel_format
Set the pixel format of the images to read. If not specified the pixel format is guessed from the
first image file in the sequence.

start_number
Set the index of the file matched by the image file pattern to start to read from. Default value is
0.

start_number_range
Set the index interval range to check when looking for the first image file in the sequence, starting
from start_number. Default value is 5.

ts_from_file
If set to 1, will set frame timestamp to modification time of image file. Note that monotonity of
timestamps is not provided: images go in the same order as without this option. Default value is 0.
If set to 2, will set frame timestamp to the modification time of the image file in nanosecond
precision.

video_size
Set the video size of the images to read. If not specified the video size is guessed from the first
image file in the sequence.

export_path_metadata
If set to 1, will add two extra fields to the metadata found in input, making them also available for
other filters (see drawtext filter for examples). Default value is 0. The extra fields are described
below:

lavf.image2dec.source_path
Corresponds to the full path to the input file being read.

lavf.image2dec.source_basename
Corresponds to the name of the file being read.

Examples

• Use ffmpeg for creating a video from the images in the file sequence img-001.jpeg, img-002.jpeg, ...,
assuming an input frame rate of 10 frames per second:

ffmpeg -framerate 10 -i 'img-%03d.jpeg' out.mkv

• As above, but start by reading from a file with index 100 in the sequence:

ffmpeg -framerate 10 -start_number 100 -i 'img-%03d.jpeg' out.mkv

• Read images matching the "*.png" glob pattern , that is all the files terminating with the ".png"
suffix:

ffmpeg -framerate 10 -pattern_type glob -i "*.png" out.mkv

libgme
The Game Music Emu library is a collection of video game music file emulators.

See <https://bitbucket.org/mpyne/game-music-emu/overview> for more information.

It accepts the following options:

track_index
Set the index of which track to demux. The demuxer can only export one track. Track indexes start at
0. Default is to pick the first track. Number of tracks is exported as tracks metadata entry.

sample_rate
Set the sampling rate of the exported track. Range is 1000 to 999999. Default is 44100.

max_size(bytes)
The demuxer buffers the entire file into memory. Adjust this value to set the maximum buffer size,
which in turn, acts as a ceiling for the size of files that can be read. Default is 50 MiB.

libmodplug
ModPlug based module demuxer

See <https://github.com/Konstanty/libmodplug>

It will export one 2-channel 16-bit 44.1 kHz audio stream. Optionally, a "pal8" 16-color video stream
can be exported with or without printed metadata.

It accepts the following options:

noise_reduction
Apply a simple low-pass filter. Can be 1 (on) or 0 (off). Default is 0.

reverb_depth
Set amount of reverb. Range 0-100. Default is 0.

reverb_delay
Set delay in ms, clamped to 40-250 ms. Default is 0.

bass_amount
Apply bass expansion a.k.a. XBass or megabass. Range is 0 (quiet) to 100 (loud). Default is 0.

bass_range
Set cutoff i.e. upper-bound for bass frequencies. Range is 10-100 Hz. Default is 0.

surround_depth
Apply a Dolby Pro-Logic surround effect. Range is 0 (quiet) to 100 (heavy). Default is 0.

surround_delay
Set surround delay in ms, clamped to 5-40 ms. Default is 0.

max_size
The demuxer buffers the entire file into memory. Adjust this value to set the maximum buffer size,
which in turn, acts as a ceiling for the size of files that can be read. Range is 0 to 100 MiB. 0
removes buffer size limit (not recommended). Default is 5 MiB.

video_stream_expr
String which is evaluated using the eval API to assign colors to the generated video stream.
Variables which can be used are "x", "y", "w", "h", "t", "speed", "tempo", "order", "pattern" and
"row".

video_stream
Generate video stream. Can be 1 (on) or 0 (off). Default is 0.

video_stream_w
Set video frame width in 'chars' where one char indicates 8 pixels. Range is 20-512. Default is 30.

video_stream_h
Set video frame height in 'chars' where one char indicates 8 pixels. Range is 20-512. Default is 30.

video_stream_ptxt
Print metadata on video stream. Includes "speed", "tempo", "order", "pattern", "row" and "ts" (time
in ms). Can be 1 (on) or 0 (off). Default is 1.

libopenmpt
libopenmpt based module demuxer

See <https://lib.openmpt.org/libopenmpt/> for more information.

Some files have multiple subsongs (tracks) this can be set with the subsong option.

It accepts the following options:

subsong
Set the subsong index. This can be either 'all', 'auto', or the index of the subsong. Subsong
indexes start at 0. The default is 'auto'.

The default value is to let libopenmpt choose.

layout
Set the channel layout. Valid values are 1, 2, and 4 channel layouts. The default value is STEREO.

sample_rate
Set the sample rate for libopenmpt to output. Range is from 1000 to INT_MAX. The value default is
48000.

mov/mp4/3gp
Demuxer for Quicktime File Format & ISO/IEC Base Media File Format (ISO/IEC 14496-12 or MPEG-4 Part 12,
ISO/IEC 15444-12 or JPEG 2000 Part 12).

Registered extensions: mov, mp4, m4a, 3gp, 3g2, mj2, psp, m4b, ism, ismv, isma, f4v

Options

This demuxer accepts the following options:

enable_drefs
Enable loading of external tracks, disabled by default. Enabling this can theoretically leak
information in some use cases.

use_absolute_path
Allows loading of external tracks via absolute paths, disabled by default. Enabling this poses a
security risk. It should only be enabled if the source is known to be non-malicious.

seek_streams_individually
When seeking, identify the closest point in each stream individually and demux packets in that stream
from identified point. This can lead to a different sequence of packets compared to demuxing linearly
from the beginning. Default is true.

ignore_editlist
Ignore any edit list atoms. The demuxer, by default, modifies the stream index to reflect the
timeline described by the edit list. Default is false.

advanced_editlist
Modify the stream index to reflect the timeline described by the edit list. "ignore_editlist" must be
set to false for this option to be effective. If both "ignore_editlist" and this option are set to
false, then only the start of the stream index is modified to reflect initial dwell time or starting
timestamp described by the edit list. Default is true.

ignore_chapters
Don't parse chapters. This includes GoPro 'HiLight' tags/moments. Note that chapters are only parsed
when input is seekable. Default is false.

use_mfra_for
For seekable fragmented input, set fragment's starting timestamp from media fragment random access
box, if present.

Following options are available:

auto
Auto-detect whether to set mfra timestamps as PTS or DTS (default)dts Set mfra timestamps as DTS

pts Set mfra timestamps as PTS

0 Don't use mfra box to set timestamps

use_tfdt
For fragmented input, set fragment's starting timestamp to "baseMediaDecodeTime" from the "tfdt" box.
Default is enabled, which will prefer to use the "tfdt" box to set DTS. Disable to use the
"earliest_presentation_time" from the "sidx" box. In either case, the timestamp from the "mfra" box
will be used if it's available and "use_mfra_for" is set to pts or dts.

export_all
Export unrecognized boxes within the udta box as metadata entries. The first four characters of the
box type are set as the key. Default is false.

export_xmp
Export entire contents of XMP_ box and uuid box as a string with key "xmp". Note that if "export_all"
is set and this option isn't, the contents of XMP_ box are still exported but with key "XMP_".
Default is false.

activation_bytes
4-byte key required to decrypt Audible AAX and AAX+ files. See Audible AAX subsection below.

audible_fixed_key
Fixed key used for handling Audible AAX/AAX+ files. It has been pre-set so should not be necessary to
specify.

decryption_key
16-byte key, in hex, to decrypt files encrypted using ISO Common Encryption (CENC/AES-128 CTR;
ISO/IEC 23001-7).

max_stts_delta
Very high sample deltas written in a trak's stts box may occasionally be intended but usually they
are written in error or used to store a negative value for dts correction when treated as signed
32-bit integers. This option lets the user set an upper limit, beyond which the delta is clamped to
1. Values greater than the limit if negative when cast to int32 are used to adjust onward dts.

Unit is the track time scale. Range is 0 to UINT_MAX. Default is "UINT_MAX - 48000*10" which allows
up to a 10 second dts correction for 48 kHz audio streams while accommodating 99.9% of "uint32"
range.

interleaved_read
Interleave packets from multiple tracks at demuxer level. For badly interleaved files, this prevents
playback issues caused by large gaps between packets in different tracks, as MOV/MP4 do not have
packet placement requirements. However, this can cause excessive seeking on very badly interleaved
files, due to seeking between tracks, so disabling it may prevent I/O issues, at the expense of
playback.

AudibleAAX

Audible AAX files are encrypted M4B files, and they can be decrypted by specifying a 4 byte activation
secret.

ffmpeg -activation_bytes 1CEB00DA -i test.aax -vn -c:a copy output.mp4

mpegts
MPEG-2 transport stream demuxer.

This demuxer accepts the following options:

resync_size
Set size limit for looking up a new synchronization. Default value is 65536.

skip_unknown_pmt
Skip PMTs for programs not defined in the PAT. Default value is 0.

fix_teletext_pts
Override teletext packet PTS and DTS values with the timestamps calculated from the PCR of the first
program which the teletext stream is part of and is not discarded. Default value is 1, set this
option to 0 if you want your teletext packet PTS and DTS values untouched.

ts_packetsize
Output option carrying the raw packet size in bytes. Show the detected raw packet size, cannot be
set by the user.

scan_all_pmts
Scan and combine all PMTs. The value is an integer with value from -1 to 1 (-1 means automatic
setting, 1 means enabled, 0 means disabled). Default value is -1.

merge_pmt_versions
Re-use existing streams when a PMT's version is updated and elementary streams move to different
PIDs. Default value is 0.

max_packet_size
Set maximum size, in bytes, of packet emitted by the demuxer. Payloads above this size are split
across multiple packets. Range is 1 to INT_MAX/2. Default is 204800 bytes.

mpjpeg
MJPEG encapsulated in multi-part MIME demuxer.

This demuxer allows reading of MJPEG, where each frame is represented as a part of
multipart/x-mixed-replace stream.

strict_mime_boundary
Default implementation applies a relaxed standard to multi-part MIME boundary detection, to prevent
regression with numerous existing endpoints not generating a proper MIME MJPEG stream. Turning this
option on by setting it to 1 will result in a stricter check of the boundary value.

rawvideo
Raw video demuxer.

This demuxer allows one to read raw video data. Since there is no header specifying the assumed video
parameters, the user must specify them in order to be able to decode the data correctly.

This demuxer accepts the following options:

framerate
Set input video frame rate. Default value is 25.

pixel_format
Set the input video pixel format. Default value is "yuv420p".

video_size
Set the input video size. This value must be specified explicitly.

For example to read a rawvideo file input.raw with ffplay, assuming a pixel format of "rgb24", a video
size of "320x240", and a frame rate of 10 images per second, use the command:

ffplay -f rawvideo -pixel_format rgb24 -video_size 320x240 -framerate 10 input.raw

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. For more information on the format, see .

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

Examples

• Render CC to ASS using the built-in decoder:

ffmpeg -i CC.rcwt.bin CC.ass

Note that if your output appears to be empty, you may have to manually set the decoder's data_field
option to pick the desired CC substream.

• Convert an RCWT backup to Scenarist (SCC) format:

ffmpeg -i CC.rcwt.bin -c:s copy CC.scc

Note that the SCC format does not support all of the possible CC extensions that can be stored in
RCWT (such as EIA-708).

sbg
SBaGen script demuxer.

This demuxer reads the script language used by SBaGen <http://uazu.net/sbagen/> to generate binaural
beats sessions. A SBG script looks like that:

-SE
a: 300-2.5/3 440+4.5/0
b: 300-2.5/0 440+4.5/3
off: -
NOW == a
+0:07:00 == b
+0:14:00 == a
+0:21:00 == b
+0:30:00 off

A SBG script can mix absolute and relative timestamps. If the script uses either only absolute timestamps
(including the script start time) or only relative ones, then its layout is fixed, and the conversion is
straightforward. On the other hand, if the script mixes both kind of timestamps, then the NOW reference
for relative timestamps will be taken from the current time of day at the time the script is read, and
the script layout will be frozen according to that reference. That means that if the script is directly
played, the actual times will match the absolute timestamps up to the sound controller's clock accuracy,
but if the user somehow pauses the playback or seeks, all times will be shifted accordingly.

tedcaptions
JSON captions used for <http://www.ted.com/>.

TED does not provide links to the captions, but they can be guessed from the page. The file
tools/bookmarklets.html from the FFmpeg source tree contains a bookmarklet to expose them.

This demuxer accepts the following option:

start_time
Set the start time of the TED talk, in milliseconds. The default is 15000 (15s). It is used to sync
the captions with the downloadable videos, because they include a 15s intro.

Example: convert the captions to a format most players understand:

ffmpeg -i http://www.ted.com/talks/subtitles/id/1/lang/en talk1-en.srt

vapoursynth
Vapoursynth wrapper.

Due to security concerns, Vapoursynth scripts will not be autodetected so the input format has to be
forced. For ff* CLI tools, add "-f vapoursynth" before the input "-i yourscript.vpy".

This demuxer accepts the following option:

max_script_size
The demuxer buffers the entire script into memory. Adjust this value to set the maximum buffer size,
which in turn, acts as a ceiling for the size of scripts that can be read. Default is 1 MiB.

w64
Sony Wave64 Audio demuxer.

This demuxer accepts the following options:

max_size
See the same option for the wav demuxer.

wav
RIFF Wave Audio demuxer.

This demuxer accepts the following options:

max_size
Specify the maximum packet size in bytes for the demuxed packets. By default this is set to 0, which
means that a sensible value is chosen based on the input format.

Description

       This document describes the supported formats (muxers and demuxers) provided by the libavformat library.

Format Options

The libavformat library provides some generic global options, which can be set on all the muxers and
demuxers. In addition each muxer or demuxer may support so-called private options, which are specific for
that component.

Options may be set by specifying -optionvalue in the FFmpeg tools, or by setting the value explicitly in
the "AVFormatContext" options or using the libavutil/opt.h API for programmatic use.

The list of supported options follows:

avioflagsflags(input/output)
Possible values:

direct
Reduce buffering.

probesizeinteger(input)
Set probing size in bytes, i.e. the size of the data to analyze to get stream information. A higher
value will enable detecting more information in case it is dispersed into the stream, but will
increase latency. Must be an integer not lesser than 32. It is 5000000 by default.

max_probe_packetsinteger(input)
Set the maximum number of buffered packets when probing a codec. Default is 2500 packets.

packetsizeinteger(output)
Set packet size.

fflagsflags
Set format flags. Some are implemented for a limited number of formats.

Possible values for input files:

discardcorrupt
Discard corrupted packets.

fastseek
Enable fast, but inaccurate seeks for some formats.

genpts
Generate missing PTS if DTS is present.

igndts
Ignore DTS if PTS is also set. In case the PTS is set, the DTS value is set to NOPTS. This is
ignored when the "nofillin" flag is set.

ignidx
Ignore index.

nobuffer
Reduce the latency introduced by buffering during initial input streams analysis.

nofillin
Do not fill in missing values in packet fields that can be exactly calculated.

noparse
Disable AVParsers, this needs "+nofillin" too.

sortdts
Try to interleave output packets by DTS. At present, available only for AVIs with an index.

Possible values for output files:

autobsf
Automatically apply bitstream filters as required by the output format. Enabled by default.

bitexact
Only write platform-, build- and time-independent data. This ensures that file and data
checksums are reproducible and match between platforms. Its primary use is for regression
testing.

flush_packets
Write out packets immediately.

shortest
Stop muxing at the end of the shortest stream. It may be needed to increase max_interleave_delta
to avoid flushing the longer streams before EOF.

seek2anyinteger(input)
Allow seeking to non-keyframes on demuxer level when supported if set to 1. Default is 0.

analyzedurationinteger(input)
Specify how many microseconds are analyzed to probe the input. A higher value will enable detecting
more accurate information, but will increase latency. It defaults to 5,000,000 microseconds = 5
seconds.

cryptokeyhexadecimalstring(input)
Set decryption key.

indexmeminteger(input)
Set max memory used for timestamp index (per stream).

rtbufsizeinteger(input)
Set max memory used for buffering real-time frames.

fdebugflags(input/output)
Print specific debug info.

Possible values:

tsmax_delayinteger(input/output)
Set maximum muxing or demuxing delay in microseconds.

fpsprobesizeinteger(input)
Set number of frames used to probe fps.

audio_preloadinteger(output)
Set microseconds by which audio packets should be interleaved earlier.

chunk_durationinteger(output)
Set microseconds for each chunk.

chunk_sizeinteger(output)
Set size in bytes for each chunk.

err_detect,f_err_detectflags(input)
Set error detection flags. "f_err_detect" is deprecated and should be used only via the ffmpeg tool.

Possible values:

crccheck
Verify embedded CRCs.

bitstream
Detect bitstream specification deviations.

buffer
Detect improper bitstream length.

explode
Abort decoding on minor error detection.

careful
Consider things that violate the spec and have not been seen in the wild as errors.

compliant
Consider all spec non compliancies as errors.

aggressive
Consider things that a sane encoder should not do as an error.

max_interleave_deltainteger(output)
Set maximum buffering duration for interleaving. The duration is expressed in microseconds, and
defaults to 10000000 (10 seconds).

To ensure all the streams are interleaved correctly, libavformat will wait until it has at least one
packet for each stream before actually writing any packets to the output file. When some streams are
"sparse" (i.e. there are large gaps between successive packets), this can result in excessive
buffering.

This field specifies the maximum difference between the timestamps of the first and the last packet
in the muxing queue, above which libavformat will output a packet regardless of whether it has queued
a packet for all the streams.

If set to 0, libavformat will continue buffering packets until it has a packet for each stream,
regardless of the maximum timestamp difference between the buffered packets.

use_wallclock_as_timestampsinteger(input)
Use wallclock as timestamps if set to 1. Default is 0.

avoid_negative_tsinteger(output)
Possible values:

make_non_negative
Shift timestamps to make them non-negative. Also note that this affects only leading negative
timestamps, and not non-monotonic negative timestamps.

make_zero
Shift timestamps so that the first timestamp is 0.

auto(default)
Enables shifting when required by the target format.

disabled
Disables shifting of timestamp.

When shifting is enabled, all output timestamps are shifted by the same amount. Audio, video, and
subtitles desynching and relative timestamp differences are preserved compared to how they would have
been without shifting.

skip_initial_bytesinteger(input)
Set number of bytes to skip before reading header and frames if set to 1. Default is 0.

correct_ts_overflowinteger(input)
Correct single timestamp overflows if set to 1. Default is 1.

flush_packetsinteger(output)
Flush the underlying I/O stream after each packet. Default is -1 (auto), which means that the
underlying protocol will decide, 1 enables it, and has the effect of reducing the latency, 0 disables
it and may increase IO throughput in some cases.

output_ts_offsetoffset(output)
Set the output time offset.

offset must be a time duration specification, see theTimedurationsectionintheffmpeg-utils(1)manual.

The offset is added by the muxer to the output timestamps.

Specifying a positive offset means that the corresponding streams are delayed bt the time duration
specified in offset. Default value is 0 (meaning that no offset is applied).

format_whitelistlist(input)
"," separated list of allowed demuxers. By default all are allowed.

dump_separatorstring(input)
Separator used to separate the fields printed on the command line about the Stream parameters. For
example, to separate the fields with newlines and indentation:

ffprobe -dump_separator "
" -i ~/videos/matrixbench_mpeg2.mpgmax_streamsinteger(input)
Specifies the maximum number of streams. This can be used to reject files that would require too many
resources due to a large number of streams.

skip_estimate_duration_from_ptsbool(input)
Skip estimation of input duration if it requires an additional probing for PTS at end of file. At
present, applicable for MPEG-PS and MPEG-TS.

duration_probesizeinteger(input)
Set probing size, in bytes, for input duration estimation when it actually requires an additional
probing for PTS at end of file (at present: MPEG-PS and MPEG-TS). It is aimed at users interested in
better durations probing for itself, or indirectly because using the concat demuxer, for example.
The typical use case is an MPEG-TS CBR with a high bitrate, high video buffering and ending cleaning
with similar PTS for video and audio: in such a scenario, the large physical gap between the last
video packet and the last audio packet makes it necessary to read many bytes in order to get the
video stream duration. Another use case is where the default probing behaviour only reaches a single
video frame which is not the last one of the stream due to frame reordering, so the duration is not
accurate. Setting this option has a performance impact even for small files because the probing size
is fixed. Default behaviour is a general purpose trade-off, largely adaptive, but the probing size
will not be extended to get streams durations at all costs. Must be an integer not lesser than 1, or
0 for default behaviour.

strict,f_strictinteger(input/output)
Specify how strictly to follow the standards. "f_strict" is deprecated and should be used only via
the ffmpeg tool.

Possible values:

very
strictly conform to an older more strict version of the spec or reference software

strict
strictly conform to all the things in the spec no matter what consequences

normalunofficial
allow unofficial extensions

experimental
allow non standardized experimental things, experimental (unfinished/work in progress/not well
tested) decoders and encoders. Note: experimental decoders can pose a security risk, do not use
this for decoding untrusted input.

Formatstreamspecifiers
Format stream specifiers allow selection of one or more streams that match specific properties.

The exact semantics of stream specifiers is defined by the avformat_match_stream_specifier() function
declared in the libavformat/avformat.h header and documented in the Streamspecifierssectionintheffmpeg(1)manual.

Metadata

       FFmpeg is able to dump metadata from media files into a simple UTF-8-encoded INI-like text file and  then
       load it back using the metadata muxer/demuxer.

       The file format is as follows:

       1.  A  file  consists  of  a  header and a number of metadata tags divided into sections, each on its own
           line.

       2.  The header is a ;FFMETADATA string, followed by a version number (now 1).

       3.  Metadata tags are of the form key=value

       4.  Immediately after header follows global metadata

       5.  After global metadata there may be sections with per-stream/per-chapter metadata.

       6.  A section starts with the section name in uppercase (i.e. STREAM or CHAPTER) in brackets ([,  ])  and
           ends with next section or end of file.

       7.  At  the  beginning  of  a  chapter section there may be an optional timebase to be used for start/end
           values. It must be in form TIMEBASE=num/den, where num and den  are  integers.  If  the  timebase  is
           missing then start/end times are assumed to be in nanoseconds.

           Next a chapter section must contain chapter start and end times in form START=num, END=num, where num
           is a positive integer.

       8.  Empty lines and lines starting with ; or # are ignored.

       9.  Metadata keys or values containing special characters (=, ;, #, \ and a newline) must be escaped with
           a backslash \.

       10. Note  that  whitespace  in  metadata  (e.g.  foo=bar) is considered to be a part of the tag (in the
           example above key is foo , value is
            bar).

       A ffmetadata file might look like this:

               ;FFMETADATA1
               title=bike\\shed
               ;this is a comment
               artist=FFmpeg troll team

               [CHAPTER]
               TIMEBASE=1/1000
               START=0
               #chapter ends at 0:01:00
               END=60000
               title=chapter \#1
               [STREAM]
               title=multi\
               line

       By using the ffmetadata muxer and demuxer it is possible to extract metadata from an  input  file  to  an
       ffmetadata file, and then transcode the file into an output file with the edited ffmetadata file.

       Extracting an ffmetadata file with ffmpeg goes as follows:

               ffmpeg -i INPUT -f ffmetadata FFMETADATAFILE

       Reinserting edited metadata information from the FFMETADATAFILE file can be done as:

               ffmpeg -i INPUT -i FFMETADATAFILE -map_metadata 1 -codec copy OUTPUT

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.

Rawmuxers
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.

ac3audio
Dolby Digital, also known as AC-3.

adxaudio
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.

aptxaudio
aptX (Audio Processing Technology for Bluetooth)

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

avs2video(avs,avs2)
AVS2-P2 (Audio Video Standard - Second generation - Part 2) / IEEE 1857.4 video

avs3video(avs3)
AVS3-P2 (Audio Video Standard - Third generation - Part 2) / IEEE 1857.10 video

cavsvideovideo(cavs)
Chinese AVS (Audio Video Standard - First generation)

codec2rawaudio
Codec 2 audio.

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

dataany
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".

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

diracvideo(drc,vc2)
BBC Dirac video.

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

dnxhdvideo(dnxhd,dnxhr)
Avid DNxHD video.

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

dtsaudio
DTS Coherent Acoustics (DCA) audio

eac3audio
Dolby Digital Plus, also known as Enhanced AC-3

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

g722audio
ITU-T G.722 audio

g723_1audio(tco,rco)
ITU-T G.723.1 audio

g726audio
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".

g726leaudio
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".

gsmaudio
Global System for Mobile Communications audio

h261video
ITU-T H.261 video

h263video
ITU-T H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2 video

h264video(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.

hevcvideo(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.

m4vvideo
MPEG-4 Part 2 video

mjpegvideo(mjpg,mjpeg)
Motion JPEG video

mlpaudio
Meridian Lossless Packing, also known as Packed PCM

mp2audio(mp2,m2a,mpa)
MPEG-1 Audio Layer II audio

mpeg1videovideo(mpg,mpeg,m1v)
MPEG-1 Part 2 video.

mpeg2videovideo(m2v)
ITU-T H.262 / MPEG-2 Part 2 video

obuvideo
AV1 low overhead Open Bitstream Units muxer.

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

rawvideovideo(yuv,rgb)
Raw uncompressed video.

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

truehdaudio(thd)
Dolby TrueHD audio

vc1video
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

RawPCMmuxers
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-2programstreammuxers
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.

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

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

MOV/MPEG-4/ISOMBFFmuxers
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_durationfrag_sizemin_frag_durationmovflags+frag_keyframemovflags+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.

Optionsbrandbrand_string
Override major brand.

empty_hdlr_namebool
Enable to skip writing the name inside a "hdlr" box. Default is "false".

encryption_keykey
set the media encryption key in hexadecimal format

encryption_kidkid
set the media encryption key identifier in hexadecimal format

encryption_schemescheme
configure the encryption scheme, allowed values are none, and cenc-aes-ctrfrag_durationduration
Create fragments that are duration microseconds long.

frag_interleavenumber
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_sizesize
create fragments that contain up to size bytes of payload data

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

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

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

min_frag_durationduration
do not create fragments that are shorter than duration microseconds long

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

movflagsflags
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_timescalescale
Set the timescale written in the movie header box ("mvhd"). Range is 1 to INT_MAX. Default is 1000.

rtpflagsflags
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_iodsbool
skip writing iods atom (default value is "true")

use_editlistbool
use edit list (default value is "auto")

use_stream_ids_as_track_idsbool
use stream ids as track ids (default value is "false")

video_track_timescalescale
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_btrtbool
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_prftoption
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_tmcdbool
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.

Optionswrite_crcbool
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.

Optionswrite_id3v2bool
Enable to write ID3v2.4 tags at the start of the stream. Default is disabled.

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

write_mpeg2bool
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.

Optionswrite_id3v2bool
Enable ID3v2 tags writing when set to 1. Default is 0 (disabled).

id3v2_versionbool
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"

Optionstypetype
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.

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

playsrepetitions
specify how many times to play the content, 0 causes an infinte 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.

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

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

namename
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.

Optionsskip_rate_checkbool
skip sample rate check (default is "false")

loopbool
set loop flag (default is "false")

reverbboolean
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.

Optionspacket_sizesize
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.

Optionsignore_readorderbool
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.

Optionsloopstartstart
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.

loopendend
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.

Optionsflipped_raw_rgbbool
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_spacesize
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_maskbool
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"sectionintheffmpeg-filtersmanual).

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>.

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

movie_timescaletimescale
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.

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

fp_formatformat
Format to output the fingerprint as. Accepts the following options:

base64
Base64 compressed fingerprint (default)compressed
Binary compressed fingerprint

raw Binary raw fingerprint

silence_thresholdthreshold
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 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 throuhg HTTPS for it to be able to perform playback on the
generated stream.

Optionsextra_window_sizeint
number of fragments kept outside of the manifest before removing from disk

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

remove_at_exitbool
remove all fragments when finished when set to "true"

window_sizeint
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.

Optionshls_init_timeduration
Set the initial target segment length. Default value is 0.

duration must be a time duration specification, see theTimedurationsectionintheffmpeg-utils(1)manual.

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_timeduration
Set the target segment length. Default value is 2.

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

hls_list_sizesize
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_thresholdsize
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_sourcesource
Start the playlist sequence number ("#EXT-X-MEDIA-SEQUENCE") according to the specified source.
Unless hls_flagssingle_file is set, it also specifies source of starting sequence numbers of segment
and subtitle filenames. In any case, if hls_flagsappend_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_numbernumber
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_flagssingle_file
is set, it also specifies starting sequence numbers of segment and subtitle filenames. Default value
is 0.

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

hls_base_urlbaseurl
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_filenamefilename
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.

strftimebool
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_mkdirbool
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_optionsoptions_list
Set output format options using a :-separated list of key=value parameters. Values containing ":"
special characters must be escaped.

hls_key_info_filekey_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_flagsperiodic_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_encbool
Enable (1) or disable (0) the AES128 encryption. When enabled every segment generated is encrypted
and the encryption key is saved as playlistname.key.

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

hls_enc_key_urlkeyurl
If set, keyurl is prepended instead of baseurl to the key filename in the playlist.

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

hls_segment_typeflags
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_filenamefilename
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_resendbool
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_flagsflags
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_typetype
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.

methodmethod
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_agentagent
Override User-Agent field in HTTP header. Applicable only for HTTP output.

var_stream_mapstream_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'. 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" \
-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_mapcc_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_namename
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_ratecount
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_persistentbool
Use persistent HTTP connections. Applicable only for HTTP output.

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

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

headersheaders
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 desgined 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.

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

start_numbercount
Start the sequence from the specified number. Default value is 1.

updatebool
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.

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

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

protocol_optsoptions_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.jpgircam
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:

titlealbumartistauthorcreatorencoderencoder_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

Optionsreserve_index_spacesize
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_frontbool
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_limitsize
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_limitduration
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.

dashbool
Create a WebM file conforming to WebM DASH specification. By default it is set to "false".

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

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

allow_raw_vfwbool
Allow raw VFW mode. By default it is set to "false".

flipped_raw_rgbbool
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_crc32bool
Write a CRC32 element inside every Level 1 element. By default it is set to "true". This option is
ignored for WebM.

default_modemode
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.