oracular (1) ffmpeg-formats.1.gz
NAME
ffmpeg-formats - FFmpeg formats
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 -option value 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:
avioflags flags (input/output)
Possible values:
direct
Reduce buffering.
probesize integer (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_packets integer (input)
Set the maximum number of buffered packets when probing a codec. Default is 2500 packets.
packetsize integer (output)
Set packet size.
fflags flags
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.
seek2any integer (input)
Allow seeking to non-keyframes on demuxer level when supported if set to 1. Default is 0.
analyzeduration integer (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.
cryptokey hexadecimal string (input)
Set decryption key.
indexmem integer (input)
Set max memory used for timestamp index (per stream).
rtbufsize integer (input)
Set max memory used for buffering real-time frames.
fdebug flags (input/output)
Print specific debug info.
Possible values:
ts
max_delay integer (input/output)
Set maximum muxing or demuxing delay in microseconds.
fpsprobesize integer (input)
Set number of frames used to probe fps.
audio_preload integer (output)
Set microseconds by which audio packets should be interleaved earlier.
chunk_duration integer (output)
Set microseconds for each chunk.
chunk_size integer (output)
Set size in bytes for each chunk.
err_detect, f_err_detect flags (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_delta integer (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_timestamps integer (input)
Use wallclock as timestamps if set to 1. Default is 0.
avoid_negative_ts integer (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_bytes integer (input)
Set number of bytes to skip before reading header and frames if set to 1. Default is 0.
correct_ts_overflow integer (input)
Correct single timestamp overflows if set to 1. Default is 1.
flush_packets integer (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_offset offset (output)
Set the output time offset.
offset must be a time duration specification, see the Time duration section in the ffmpeg-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_whitelist list (input)
"," separated list of allowed demuxers. By default all are allowed.
dump_separator string (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.mpg
max_streams integer (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_pts bool (input)
Skip estimation of input duration when calculated using PTS. At present, applicable for MPEG-PS and
MPEG-TS.
strict, f_strict integer (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
normal
unofficial
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.
Format stream specifiers
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 Stream specifiers section in the
ffmpeg(1) manual.
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_loop bool
Ignore the loop variable in the file if set. Default is enabled.
-max_fps int
Maximum framerate in frames per second. Default of 0 imposes no limit.
-default_fps int
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_search bool
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:
"file path"
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.
"ffconcat version 1.0"
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.
"duration dur"
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.
"inpoint timestamp"
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.
"outpoint timestamp"
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_metadata key=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_meta key 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.
"option key value"
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_id id"
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_meta key value"
Metadata for the stream. Can be present multiple times.
"stream_codec value"
Codec for the stream.
"stream_extradata hex_string"
Extradata for the string, encoded in hexadecimal.
"chapter id start end"
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).
Seeking is not supported at this time.
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:
title int
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_start int
The chapter, or PTT (part-of-title), number to start at. Not applicable to menus. Default is 1.
chapter_end int
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.
angle int
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.
region int
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".
menu bool
Demux menu assets instead of navigating a title. Requires exact coordinates of the menu (menu_lu,
menu_vts, pgc, pg). Default is false.
menu_lu int
The menu language to demux. In DVD, menus are grouped by language. Default is 0, the first language
unit.
menu_vts int
The VTS where the menu lives, or 0 if it is a VMG menu (root-level). Default is 0, VMG menu.
pgc int
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.
pg int
The entry PG to start playback, in conjunction with pgc. Alternative to setting title. Chapter
markers are not supported at this time. Default is 0, automatically resolve from value of title, or
start from the beginning (PG 1) of the menu.
preindex bool
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. Not applicable to menus.
Default is 0, false.
trim bool
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.
Options
merge_alpha bool
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_metadata bool
Allocate the streams according to the onMetaData array content.
-flv_ignore_prevtag bool
Ignore the size of previous tag value.
-flv_full_metadata bool
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.
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, will be removed)
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.
Audible AAX
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
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.
MUXERS
Muxers are configured elements in FFmpeg which allow writing multimedia streams to a particular type of
file.
When you configure your FFmpeg build, all the supported muxers are enabled by default. You can list all
available muxers using the configure option "--list-muxers".
You can disable all the muxers with the configure option "--disable-muxers" and selectively enable /
disable single muxers with the options "--enable-muxer=MUXER" / "--disable-muxer=MUXER".
The option "-muxers" of the ff* tools will display the list of enabled muxers. Use "-formats" to view a
combined list of enabled demuxers and muxers.
A description of some of the currently available muxers follows.
Raw muxers
This section covers raw muxers. They accept a single stream matching the designated codec. They do not
store timestamps or metadata. The recognized extension is the same as the muxer name unless indicated
otherwise.
It comprises the following muxers. The media type and the eventual extensions used to automatically
selects the muxer from the output extensions are also shown.
ac3 audio
Dolby Digital, also known as AC-3.
adx audio
CRI Middleware ADX audio.
This muxer will write out the total sample count near the start of the first packet when the output
is seekable and the count can be stored in 32 bits.
aptx audio
aptX (Audio Processing Technology for Bluetooth)
aptx_hd audio (aptxdh)
aptX HD (Audio Processing Technology for Bluetooth) audio
avs2 video (avs, avs2)
AVS2-P2 (Audio Video Standard - Second generation - Part 2) / IEEE 1857.4 video
avs3 video (avs3)
AVS3-P2 (Audio Video Standard - Third generation - Part 2) / IEEE 1857.10 video
cavsvideo video (cavs)
Chinese AVS (Audio Video Standard - First generation)
codec2raw audio
Codec 2 audio.
No extension is registered so format name has to be supplied e.g. with the ffmpeg CLI tool "-f
codec2raw".
data any
Generic data muxer.
This muxer accepts a single stream with any codec of any type. The input stream has to be selected
using the "-map" option with the ffmpeg CLI tool.
No extension is registered so format name has to be supplied e.g. with the ffmpeg CLI tool "-f data".
dfpwm audio (dfpwm)
Raw DFPWM1a (Dynamic Filter Pulse With Modulation) audio muxer.
dirac video (drc, vc2)
BBC Dirac video.
The Dirac Pro codec is a subset and is standardized as SMPTE VC-2.
dnxhd video (dnxhd, dnxhr)
Avid DNxHD video.
It is standardized as SMPTE VC-3. Accepts DNxHR streams.
dts audio
DTS Coherent Acoustics (DCA) audio
eac3 audio
Dolby Digital Plus, also known as Enhanced AC-3
evc video (evc)
MPEG-5 Essential Video Coding (EVC) / EVC / MPEG-5 Part 1 EVC video
g722 audio
ITU-T G.722 audio
g723_1 audio (tco, rco)
ITU-T G.723.1 audio
g726 audio
ITU-T G.726 big-endian ("left-justified") audio.
No extension is registered so format name has to be supplied e.g. with the ffmpeg CLI tool "-f g726".
g726le audio
ITU-T G.726 little-endian ("right-justified") audio.
No extension is registered so format name has to be supplied e.g. with the ffmpeg CLI tool "-f
g726le".
gsm audio
Global System for Mobile Communications audio
h261 video
ITU-T H.261 video
h263 video
ITU-T H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2 video
h264 video (h264, 264)
ITU-T H.264 / MPEG-4 Part 10 AVC video. Bitstream shall be converted to Annex B syntax if it's in
length-prefixed mode.
hevc video (hevc, h265, 265)
ITU-T H.265 / MPEG-H Part 2 HEVC video. Bitstream shall be converted to Annex B syntax if it's in
length-prefixed mode.
m4v video
MPEG-4 Part 2 video
mjpeg video (mjpg, mjpeg)
Motion JPEG video
mlp audio
Meridian Lossless Packing, also known as Packed PCM
mp2 audio (mp2, m2a, mpa)
MPEG-1 Audio Layer II audio
mpeg1video video (mpg, mpeg, m1v)
MPEG-1 Part 2 video.
mpeg2video video (m2v)
ITU-T H.262 / MPEG-2 Part 2 video
obu video
AV1 low overhead Open Bitstream Units muxer.
Temporal delimiter OBUs will be inserted in all temporal units of the stream.
rawvideo video (yuv, rgb)
Raw uncompressed video.
sbc audio (sbc, msbc)
Bluetooth SIG low-complexity subband codec audio
truehd audio (thd)
Dolby TrueHD audio
vc1 video
SMPTE 421M / VC-1 video
Examples
• Store raw video frames with the rawvideo muxer using ffmpeg:
ffmpeg -f lavfi -i testsrc -t 10 -s hd1080p testsrc.yuv
Since the rawvideo muxer do not store the information related to size and format, this information
must be provided when demuxing the file:
ffplay -video_size 1920x1080 -pixel_format rgb24 -f rawvideo testsrc.rgb
Raw PCM muxers
This section covers raw PCM (Pulse-Code Modulation) audio muxers.
They accept a single stream matching the designated codec. They do not store timestamps or metadata. The
recognized extension is the same as the muxer name.
It comprises the following muxers. The optional additional extension used to automatically select the
muxer from the output extension is also shown in parentheses.
alaw (al)
PCM A-law
f32be
PCM 32-bit floating-point big-endian
f32le
PCM 32-bit floating-point little-endian
f64be
PCM 64-bit floating-point big-endian
f64le
PCM 64-bit floating-point little-endian
mulaw (ul)
PCM mu-law
s16be
PCM signed 16-bit big-endian
s16le
PCM signed 16-bit little-endian
s24be
PCM signed 24-bit big-endian
s24le
PCM signed 24-bit little-endian
s32be
PCM signed 32-bit big-endian
s32le
PCM signed 32-bit little-endian
s8 (sb)
PCM signed 8-bit
u16be
PCM unsigned 16-bit big-endian
u16le
PCM unsigned 16-bit little-endian
u24be
PCM unsigned 24-bit big-endian
u24le
PCM unsigned 24-bit little-endian
u32be
PCM unsigned 32-bit big-endian
u32le
PCM unsigned 32-bit little-endian
u8 (ub)
PCM unsigned 8-bit
vidc
PCM Archimedes VIDC
MPEG-1/MPEG-2 program stream muxers
This section covers formats belonging to the MPEG-1 and MPEG-2 Systems family.
The MPEG-1 Systems format (also known as ISO/IEEC 11172-1 or MPEG-1 program stream) has been adopted for
the format of media track stored in VCD (Video Compact Disc).
The MPEG-2 Systems standard (also known as ISO/IEEC 13818-1) covers two containers formats, one known as
transport stream and one known as program stream; only the latter is covered here.
The MPEG-2 program stream format (also known as VOB due to the corresponding file extension) is an
extension of MPEG-1 program stream: in addition to support different codecs for the audio and video
streams, it also stores subtitles and navigation metadata. MPEG-2 program stream has been adopted for
storing media streams in SVCD and DVD storage devices.
This section comprises the following muxers.
mpeg (mpg,mpeg)
MPEG-1 Systems / MPEG-1 program stream muxer.
vcd MPEG-1 Systems / MPEG-1 program stream (VCD) muxer.
This muxer can be used to generate tracks in the format accepted by the VCD (Video Compact Disc)
storage devices.
It is the same as the mpeg muxer with a few differences.
vob MPEG-2 program stream (VOB) muxer.
dvd MPEG-2 program stream (DVD VOB) muxer.
This muxer can be used to generate tracks in the format accepted by the DVD (Digital Versatile Disc)
storage devices.
This is the same as the vob muxer with a few differences.
svcd (vob)
MPEG-2 program stream (SVCD VOB) muxer.
This muxer can be used to generate tracks in the format accepted by the SVCD (Super Video Compact
Disc) storage devices.
This is the same as the vob muxer with a few differences.
Options
muxrate rate
Set user-defined mux rate expressed as a number of bits/s. If not specied the automatically computed
mux rate is employed. Default value is 0.
preload delay
Set initial demux-decode delay in microseconds. Default value is 500000.
MOV/MPEG-4/ISOMBFF muxers
This section covers formats belonging to the QuickTime / MOV family, including the MPEG-4 Part 14 format
and ISO base media file format (ISOBMFF). These formats share a common structure based on the ISO base
media file format (ISOBMFF).
The MOV format was originally developed for use with Apple QuickTime. It was later used as the basis for
the MPEG-4 Part 1 (later Part 14) format, also known as ISO/IEC 14496-1. That format was then generalized
into ISOBMFF, also named MPEG-4 Part 12 format, ISO/IEC 14496-12, or ISO/IEC 15444-12.
It comprises the following muxers.
3gp Third Generation Partnership Project (3GPP) format for 3G UMTS multimedia services
3g2 Third Generation Partnership Project 2 (3GP2 or 3GPP2) format for 3G CDMA2000 multimedia services,
similar to 3gp with extensions and limitations
f4v Adobe Flash Video format
ipod
MPEG-4 audio file format, as MOV/MP4 but limited to contain only audio streams, typically played with
the Apple ipod device
ismv
Microsoft IIS (Internet Information Services) Smooth Streaming Audio/Video (ISMV or ISMA) format.
This is based on MPEG-4 Part 14 format with a few incompatible variants, used to stream media files
for the Microsoft IIS server.
mov QuickTime player format identified by the ".mov" extension
mp4 MP4 or MPEG-4 Part 14 format
psp PlayStation Portable MP4/MPEG-4 Part 14 format variant. This is based on MPEG-4 Part 14 format with a
few incompatible variants, used to play files on PlayStation devices.
Fragmentation
The mov, mp4, and ismv muxers support fragmentation. Normally, a MOV/MP4 file has all the metadata about
all packets stored in one location.
This data is usually written at the end of the file, but it can be moved to the start for better playback
by adding "+faststart" to the "-movflags", or using the qt-faststart tool).
A fragmented file consists of a number of fragments, where packets and metadata about these packets are
stored together. Writing a fragmented file has the advantage that the file is decodable even if the
writing is interrupted (while a normal MOV/MP4 is undecodable if it is not properly finished), and it
requires less memory when writing very long files (since writing normal MOV/MP4 files stores info about
every single packet in memory until the file is closed). The downside is that it is less compatible with
other applications.
Fragmentation is enabled by setting one of the options that define how to cut the file into fragments:
frag_duration
frag_size
min_frag_duration
movflags +frag_keyframe
movflags +frag_custom
If more than one condition is specified, fragments are cut when one of the specified conditions is
fulfilled. The exception to this is the option min_frag_duration, which has to be fulfilled for any of
the other conditions to apply.
Options
brand brand_string
Override major brand.
empty_hdlr_name bool
Enable to skip writing the name inside a "hdlr" box. Default is "false".
encryption_key key
set the media encryption key in hexadecimal format
encryption_kid kid
set the media encryption key identifier in hexadecimal format
encryption_scheme scheme
configure the encryption scheme, allowed values are none, and cenc-aes-ctr
frag_duration duration
Create fragments that are duration microseconds long.
frag_interleave number
Interleave samples within fragments (max number of consecutive samples, lower is tighter
interleaving, but with more overhead. It is set to 0 by default.
frag_size size
create fragments that contain up to size bytes of payload data
iods_audio_profile profile
specify iods number for the audio profile atom (from -1 to 255), default is -1
iods_video_profile profile
specify iods number for the video profile atom (from -1 to 255), default is -1
ism_lookahead num_entries
specify number of lookahead entries for ISM files (from 0 to 255), default is 0
min_frag_duration duration
do not create fragments that are shorter than duration microseconds long
moov_size bytes
Reserves space for the moov atom at the beginning of the file instead of placing the moov atom at the
end. If the space reserved is insufficient, muxing will fail.
mov_gamma gamma
specify gamma value for gama atom (as a decimal number from 0 to 10), default is 0.0, must be set
together with "+ movflags"
movflags flags
Set various muxing switches. The following flags can be used:
cmaf
write CMAF (Common Media Application Format) compatible fragmented MP4 output
dash
write DASH (Dynamic Adaptive Streaming over HTTP) compatible fragmented MP4 output
default_base_moof
Similarly to the omit_tfhd_offset flag, this flag avoids writing the absolute base_data_offset
field in tfhd atoms, but does so by using the new default-base-is-moof flag instead. This flag is
new from 14496-12:2012. This may make the fragments easier to parse in certain circumstances
(avoiding basing track fragment location calculations on the implicit end of the previous track
fragment).
delay_moov
delay writing the initial moov until the first fragment is cut, or until the first fragment flush
disable_chpl
Disable Nero chapter markers (chpl atom). Normally, both Nero chapters and a QuickTime chapter
track are written to the file. With this option set, only the QuickTime chapter track will be
written. Nero chapters can cause failures when the file is reprocessed with certain tagging
programs, like mp3Tag 2.61a and iTunes 11.3, most likely other versions are affected as well.
faststart
Run a second pass moving the index (moov atom) to the beginning of the file. This operation can
take a while, and will not work in various situations such as fragmented output, thus it is not
enabled by default.
frag_custom
Allow the caller to manually choose when to cut fragments, by calling "av_write_frame(ctx, NULL)"
to write a fragment with the packets written so far. (This is only useful with other applications
integrating libavformat, not from ffmpeg.)
frag_discont
signal that the next fragment is discontinuous from earlier ones
frag_every_frame
fragment at every frame
frag_keyframe
start a new fragment at each video keyframe
global_sidx
write a global sidx index at the start of the file
isml
create a live smooth streaming feed (for pushing to a publishing point)
negative_cts_offsets
Enables utilization of version 1 of the CTTS box, in which the CTS offsets can be negative. This
enables the initial sample to have DTS/CTS of zero, and reduces the need for edit lists for some
cases such as video tracks with B-frames. Additionally, eases conformance with the DASH-IF
interoperability guidelines.
This option is implicitly set when writing ismv (Smooth Streaming) files.
omit_tfhd_offset
Do not write any absolute base_data_offset in tfhd atoms. This avoids tying fragments to absolute
byte positions in the file/streams.
prefer_icc
If writing colr atom prioritise usage of ICC profile if it exists in stream packet side data.
rtphint
add RTP hinting tracks to the output file
separate_moof
Write a separate moof (movie fragment) atom for each track. Normally, packets for all tracks are
written in a moof atom (which is slightly more efficient), but with this option set, the muxer
writes one moof/mdat pair for each track, making it easier to separate tracks.
skip_sidx
Skip writing of sidx atom. When bitrate overhead due to sidx atom is high, this option could be
used for cases where sidx atom is not mandatory. When the global_sidx flag is enabled, this
option is ignored.
skip_trailer
skip writing the mfra/tfra/mfro trailer for fragmented files
use_metadata_tags
use mdta atom for metadata
write_colr
write colr atom even if the color info is unspecified. This flag is experimental, may be renamed
or changed, do not use from scripts.
write_gama
write deprecated gama atom
movie_timescale scale
Set the timescale written in the movie header box ("mvhd"). Range is 1 to INT_MAX. Default is 1000.
rtpflags flags
Add RTP hinting tracks to the output file.
The following flags can be used:
h264_mode0
use mode 0 for H.264 in RTP
latm
use MP4A-LATM packetization instead of MPEG4-GENERIC for AAC
rfc2190
use RFC 2190 packetization instead of RFC 4629 for H.263
send_bye
send RTCP BYE packets when finishing
skip_rtcp
do not send RTCP sender reports
skip_iods bool
skip writing iods atom (default value is "true")
use_editlist bool
use edit list (default value is "auto")
use_stream_ids_as_track_ids bool
use stream ids as track ids (default value is "false")
video_track_timescale scale
Set the timescale used for video tracks. Range is 0 to INT_MAX. If set to 0, the timescale is
automatically set based on the native stream time base. Default is 0.
write_btrt bool
Force or disable writing bitrate box inside stsd box of a track. The box contains decoding buffer
size (in bytes), maximum bitrate and average bitrate for the track. The box will be skipped if none
of these values can be computed. Default is -1 or "auto", which will write the box only in MP4 mode.
write_prft option
Write producer time reference box (PRFT) with a specified time source for the NTP field in the PRFT
box. Set value as wallclock to specify timesource as wallclock time and pts to specify timesource as
input packets' PTS values.
write_tmcd bool
Specify "on" to force writing a timecode track, "off" to disable it and "auto" to write a timecode
track only for mov and mp4 output (default).
Setting value to pts is applicable only for a live encoding use case, where PTS values are set as as
wallclock time at the source. For example, an encoding use case with decklink capture source where
video_pts and audio_pts are set to abs_wallclock.
Examples
• Push Smooth Streaming content in real time to a publishing point on IIS with the ismv muxer using
ffmpeg:
ffmpeg -re <<normal input/transcoding options>> -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1)
a64
A64 Commodore 64 video muxer.
This muxer accepts a single "a64_multi" or "a64_multi5" codec video stream.
ac4
Raw AC-4 audio muxer.
This muxer accepts a single "ac4" audio stream.
Options
write_crc bool
when enabled, write a CRC checksum for each packet to the output, default is "false"
adts
Audio Data Transport Stream muxer.
It accepts a single AAC stream.
Options
write_id3v2 bool
Enable to write ID3v2.4 tags at the start of the stream. Default is disabled.
write_apetag bool
Enable to write APE tags at the end of the stream. Default is disabled.
write_mpeg2 bool
Enable to set MPEG version bit in the ADTS frame header to 1 which indicates MPEG-2. Default is 0,
which indicates MPEG-4.
aea
MD STUDIO audio muxer.
This muxer accepts a single ATRAC1 audio stream with either one or two channels and a sample rate of
44100Hz.
As AEA supports storing the track title, this muxer will also write the title from stream's metadata to
the container.
aiff
Audio Interchange File Format muxer.
Options
write_id3v2 bool
Enable ID3v2 tags writing when set to 1. Default is 0 (disabled).
id3v2_version bool
Select ID3v2 version to write. Currently only version 3 and 4 (aka. ID3v2.3 and ID3v2.4) are
supported. The default is version 4.
alp
High Voltage Software's Lego Racers game audio muxer.
It accepts a single ADPCM_IMA_ALP stream with no more than 2 channels and a sample rate not greater than
44100 Hz.
Extensions: "tun", "pcm"
Options
type type
Set file type.
type accepts the following values:
tun Set file type as music. Must have a sample rate of 22050 Hz.
pcm Set file type as sfx.
auto
Set file type as per output file extension. ".pcm" results in type "pcm" else type "tun" is set.
(default)
amr
3GPP AMR (Adaptive Multi-Rate) audio muxer.
It accepts a single audio stream containing an AMR NB stream.
amv
AMV (Actions Media Video) format muxer.
apm
Ubisoft Rayman 2 APM audio muxer.
It accepts a single ADPCM IMA APM audio stream.
apng
Animated Portable Network Graphics muxer.
It accepts a single APNG video stream.
Options
final_delay delay
Force a delay expressed in seconds after the last frame of each repetition. Default value is 0.0.
plays repetitions
specify how many times to play the content, 0 causes an 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.
Options
version_major version
override file major version, specified as an integer, default value is 2
version_minor version
override file minor version, specified as an integer, default value is 1
name name
Embed file name into file, if not specified use the output file name. The name is truncated to 8
characters.
argo_cvg
Argonaut Games CVG audio muxer.
It accepts a single one-channel ADPCM 22050Hz audio stream.
The loop and reverb options set the corresponding flags in the header which can be later retrieved to
process the audio stream accordingly.
Options
skip_rate_check bool
skip sample rate check (default is "false")
loop bool
set loop flag (default is "false")
reverb boolean
set reverb flag (default is "true")
asf, asf_stream
Advanced / Active Systems (or Streaming) Format audio muxer.
The asf_stream variant should be selected for streaming.
Note that Windows Media Audio (wma) and Windows Media Video (wmv) use this muxer too.
Options
packet_size size
Set the muxer packet size as a number of bytes. By tuning this setting you may reduce data
fragmentation or muxer overhead depending on your source. Default value is 3200, minimum is 100,
maximum is "64Ki".
ass
ASS/SSA (SubStation Alpha) subtitles muxer.
It accepts a single ASS subtitles stream.
Options
ignore_readorder bool
Write dialogue events immediately, even if they are out-of-order, default is "false", otherwise they
are cached until the expected time event is found.
ast
AST (Audio Stream) muxer.
This format is used to play audio on some Nintendo Wii games.
It accepts a single audio stream.
The loopstart and loopend options can be used to define a section of the file to loop for players
honoring such options.
Options
loopstart start
Specify loop start position expressesd in milliseconds, from -1 to "INT_MAX", in case -1 is set then
no loop is specified (default -1) and the loopend value is ignored.
loopend end
Specify loop end position expressed in milliseconds, from 0 to "INT_MAX", default is 0, in case 0 is
set it assumes the total stream duration.
au
SUN AU audio muxer.
It accepts a single audio stream.
avi
Audio Video Interleaved muxer.
AVI is a proprietary format developed by Microsoft, and later formally specified through the Open DML
specification.
Because of differences in players implementations, it might be required to set some options to make sure
that the generated output can be correctly played by the target player.
Options
flipped_raw_rgb bool
If set to "true", store positive height for raw RGB bitmaps, which indicates bitmap is stored bottom-
up. Note that this option does not flip the bitmap which has to be done manually beforehand, e.g. by
using the vflip filter. Default is "false" and indicates bitmap is stored top down.
reserve_index_space size
Reserve the specified amount of bytes for the OpenDML master index of each stream within the file
header. By default additional master indexes are embedded within the data packets if there is no
space left in the first master index and are linked together as a chain of indexes. This index
structure can cause problems for some use cases, e.g. third-party software strictly relying on the
OpenDML index specification or when file seeking is slow. Reserving enough index space in the file
header avoids these problems.
The required index space depends on the output file size and should be about 16 bytes per gigabyte.
When this option is omitted or set to zero the necessary index space is guessed.
Default value is 0.
write_channel_mask bool
Write the channel layout mask into the audio stream header.
This option is enabled by default. Disabling the channel mask can be useful in specific scenarios,
e.g. when merging multiple audio streams into one for compatibility with software that only supports
a single audio stream in AVI (see the "amerge" section in the ffmpeg-filters manual).
avif
AV1 (Alliance for Open Media Video codec 1) image format muxer.
This muxers stores images encoded using the AV1 codec.
It accepts one or two video streams. In case two video streams are provided, the second one shall contain
a single plane storing the alpha mask.
In case more than one image is provided, the generated output is considered an animated AVIF and the
number of loops can be specified with the loop option.
This is based on the specification by Alliance for Open Media at url
<https://aomediacodec.github.io/av1-avif>.
Options
loop count
number of times to loop an animated AVIF, 0 specify an infinite loop, default is 0
movie_timescale timescale
Set the timescale written in the movie header box ("mvhd"). Range is 1 to INT_MAX. Default is 1000.
avm2
ShockWave Flash (SWF) / ActionScript Virtual Machine 2 (AVM2) format muxer.
It accepts one audio stream, one video stream, or both.
bit
G.729 (.bit) file format muxer.
It accepts a single G.729 audio stream.
caf
Apple CAF (Core Audio Format) muxer.
It accepts a single audio stream.
codec2
Codec2 audio audio muxer.
It accepts a single codec2 audio stream.
chromaprint
Chromaprint fingerprinter muxers.
To enable compilation of this filter you need to configure FFmpeg with "--enable-chromaprint".
This muxer feeds audio data to the Chromaprint library, which generates a fingerprint for the provided
audio data. See: <https://acoustid.org/chromaprint>
It takes a single signed native-endian 16-bit raw audio stream of at most 2 channels.
Options
algorithm version
Select version of algorithm to fingerprint with. Range is 0 to 4. Version 3 enables silence
detection. Default is 1.
fp_format format
Format to output the fingerprint as. Accepts the following options:
base64
Base64 compressed fingerprint (default)
compressed
Binary compressed fingerprint
raw Binary raw fingerprint
silence_threshold threshold
Threshold for detecting silence. Range is from -1 to 32767, where -1 disables silence detection.
Silence detection can only be used with version 3 of the algorithm.
Silence detection must be disabled for use with the AcoustID service. Default is -1.
crc
CRC (Cyclic Redundancy Check) muxer.
This muxer computes and prints the Adler-32 CRC of all the input audio and video frames. By default audio
frames are converted to signed 16-bit raw audio and video frames to raw video before computing the CRC.
The output of the muxer consists of a single line of the form: CRC=0xCRC, where CRC is a hexadecimal
number 0-padded to 8 digits containing the CRC for all the decoded input frames.
See also the framecrc muxer.
Examples
• Use ffmpeg to compute the CRC of the input, and store it in the file out.crc:
ffmpeg -i INPUT -f crc out.crc
• Use ffmpeg to print the CRC to stdout with the command:
ffmpeg -i INPUT -f crc -
• You can select the output format of each frame with ffmpeg by specifying the audio and video codec
and format. For example, to compute the CRC of the input audio converted to PCM unsigned 8-bit and
the input video converted to MPEG-2 video, use the command:
ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc -
dash
Dynamic Adaptive Streaming over HTTP (DASH) muxer.
This muxer creates segments and manifest files according to the MPEG-DASH standard ISO/IEC 23009-1:2014
and following standard updates.
For more information see:
• ISO DASH Specification:
<http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip>
• WebM DASH Specification:
<https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification>
This muxer creates an MPD (Media Presentation Description) manifest file and segment files for each
stream. Segment files are placed in the same directory of the MPD manifest file.
The segment filename might contain pre-defined identifiers used in the manifest "SegmentTemplate" section
as defined in section 5.3.9.4.4 of the standard.
Available identifiers are "$RepresentationID$", "$Number$", "$Bandwidth$", and "$Time$". In addition to
the standard identifiers, an ffmpeg-specific "$ext$" identifier is also supported. When specified, ffmpeg
will replace "$ext$" in the file name with muxing format's extensions such as "mp4", "webm" etc.
Options
adaptation_sets adaptation_sets
Assign streams to adaptation sets, specified in the MPD manifest "AdaptationSets" section.
An adaptation set contains a set of one or more streams accessed as a single subset, e.g.
corresponding streams encoded at different size selectable by the user depending on the available
bandwidth, or to different audio streams with a different language.
Each adaptation set is specified with the syntax:
id=<index>,streams=<streams>
where index must be a numerical index, and streams is a sequence of ","-separated stream indices.
Multiple adaptation sets can be specified, separated by spaces.
To map all video (or audio) streams to an adaptation set, "v" (or "a") can be used as stream
identifier instead of IDs.
When no assignment is defined, this defaults to an adaptation set for each stream.
The following optional fields can also be specified:
descriptor
Define the descriptor as defined by ISO/IEC 23009-1:2014/Amd.2:2015.
For example:
<SupplementalProperty schemeIdUri=\"urn:mpeg:dash:srd:2014\" value=\"0,0,0,1,1,2,2\"/>
The descriptor string should be a self-closing XML tag.
frag_duration
Override the global fragment duration specified with the frag_duration option.
frag_type
Override the global fragment type specified with the frag_type option.
seg_duration
Override the global segment duration specified with the seg_duration option.
trick_id
Mark an adaptation set as containing streams meant to be used for Trick Mode for the referenced
adaptation set.
A few examples of possible values for the adaptation_sets option follow:
id=0,seg_duration=2,frag_duration=1,frag_type=duration,streams=v id=1,seg_duration=2,frag_type=none,streams=a
id=0,seg_duration=2,frag_type=none,streams=0 id=1,seg_duration=10,frag_type=none,trick_id=0,streams=1
dash_segment_type type
Set DASH segment files type.
Possible values:
auto
The dash segment files format will be selected based on the stream codec. This is the default
mode.
mp4 the dash segment files will be in ISOBMFF/MP4 format
webm
the dash segment files will be in WebM format
extra_window_size size
Set the maximum number of segments kept outside of the manifest before removing from disk.
format_options options_list
Set container format (mp4/webm) options using a ":"-separated list of key=value parameters. Values
containing ":" special characters must be escaped.
frag_duration duration
Set the length in seconds of fragments within segments, fractional value can also be set.
frag_type type
Set the type of interval for fragmentation.
Possible values:
auto
set one fragment per segment
every_frame
fragment at every frame
duration
fragment at specific time intervals
pframes
fragment at keyframes and following P-Frame reordering (Video only, experimental)
global_sidx bool
Write global "SIDX" atom. Applicable only for single file, mp4 output, non-streaming mode.
hls_master_name file_name
HLS master playlist name. Default is master.m3u8.
hls_playlist bool
Generate HLS playlist files. The master playlist is generated with filename specified by the
hls_master_name option. One media playlist file is generated for each stream with filenames
media_0.m3u8, media_1.m3u8, etc.
http_opts http_opts
Specify a list of ":"-separated key=value options to pass to the underlying HTTP protocol. Applicable
only for HTTP output.
http_persistent bool
Use persistent HTTP connections. Applicable only for HTTP output.
http_user_agent user_agent
Override User-Agent field in HTTP header. Applicable only for HTTP output.
ignore_io_errors bool
Ignore IO errors during open and write. Useful for long-duration runs with network output. This is
disabled by default.
index_correction bool
Enable or disable segment index correction logic. Applicable only when use_template is enabled and
use_timeline is disabled. This is disabled by default.
When enabled, the logic monitors the flow of segment indexes. If a streams's segment index value is
not at the expected real time position, then the logic corrects that index value.
Typically this logic is needed in live streaming use cases. The network bandwidth fluctuations are
common during long run streaming. Each fluctuation can cause the segment indexes fall behind the
expected real time position.
init_seg_name init_name
DASH-templated name to use for the initialization segment. Default is
"init-stream$RepresentationID$.$ext$". "$ext$" is replaced with the file name extension specific for
the segment format.
ldash bool
Enable Low-latency Dash by constraining the presence and values of some elements. This is disabled by
default.
lhls bool
Enable Low-latency HLS (LHLS). Add "#EXT-X-PREFETCH" tag with current segment's URI. hls.js player
folks are trying to standardize an open LHLS spec. The draft spec is available at
<https://github.com/video-dev/hlsjs-rfcs/blob/lhls-spec/proposals/0001-lhls.md>.
This option tries to comply with the above open spec. It enables streaming and hls_playlist options
automatically. This is an experimental feature.
Note: This is not Apple's version LHLS. See
<https://datatracker.ietf.org/doc/html/draft-pantos-hls-rfc8216bis>
master_m3u8_publish_rate segment_intervals_count
Publish master playlist repeatedly every after specified number of segment intervals.
max_playback_rate rate
Set the maximum playback rate indicated as appropriate for the purposes of automatically adjusting
playback latency and buffer occupancy during normal playback by clients.
media_seg_name segment_name
DASH-templated name to use for the media segments. Default is
"chunk-stream$RepresentationID$-$Number%05d$.$ext$". "$ext$" is replaced with the file name extension
specific for the segment format.
method method
Use the given HTTP method to create output files. Generally set to "PUT" or "POST".
min_playback_rate rate
Set the minimum playback rate indicated as appropriate for the purposes of automatically adjusting
playback latency and buffer occupancy during normal playback by clients.
mpd_profile flags
Set one or more MPD manifest profiles.
Possible values:
dash
MPEG-DASH ISO Base media file format live profile
dvb_dash
DVB-DASH profile
Default value is "dash".
remove_at_exit bool
Enable or disable removal of all segments when finished. This is disabled by default.
seg_duration duration
Set the segment length in seconds (fractional value can be set). The value is treated as average
segment duration when the use_template option is enabled and the use_timeline option is disabled and
as minimum segment duration for all the other use cases.
Default value is 5.
single_file bool
Enable or disable storing all segments in one file, accessed using byte ranges. This is disabled by
default.
The name of the single file can be specified with the single_file_name option, if not specified
assume the basename of the manifest file with the output format extension.
single_file_name file_name
DASH-templated name to use for the manifest "baseURL" element. Imply that the single_file option is
set to true. In the template, "$ext$" is replaced with the file name extension specific for the
segment format.
streaming bool
Enable or disable chunk streaming mode of output. In chunk streaming mode, each frame will be a
"moof" fragment which forms a chunk. This is disabled by default.
target_latency target_latency
Set an intended target latency in seconds for serving (fractional value can be set). Applicable only
when the streaming and write_prft options are enabled. This is an informative fields clients can use
to measure the latency of the service.
timeout timeout
Set timeout for socket I/O operations expressed in seconds (fractional value can be set). Applicable
only for HTTP output.
update_period period
Set the MPD update period, for dynamic content. The unit is second. If set to 0, the period is
automatically computed.
Default value is 0.
use_template bool
Enable or disable use of "SegmentTemplate" instead of "SegmentList" in the manifest. This is enabled
by default.
use_timeline bool
Enable or disable use of "SegmentTimeline" within the "SegmentTemplate" manifest section. This is
enabled by default.
utc_timing_url url
URL of the page that will return the UTC timestamp in ISO format, for example
"https://time.akamai.com/?iso"
window_size size
Set the maximum number of segments kept in the manifest, discard the oldest one. This is useful for
live streaming.
If the value is 0, all segments are kept in the manifest. Default value is 0.
write_prft write_prft
Write Producer Reference Time elements on supported streams. This also enables writing prft boxes in
the underlying muxer. Applicable only when the utc_url option is enabled. It is set to auto by
default, in which case the muxer will attempt to enable it only in modes that require it.
Example
Generate a DASH output reading from an input source in realtime using ffmpeg.
Two multimedia streams are generated from the input file, both containing a video stream encoded through
libx264, and an audio stream encoded with libfdk_aac. The first multimedia stream contains video with a
bitrate of 800k and audio at the default rate, the second with video scaled to 320x170 pixels at 300k and
audio resampled at 22005 Hz.
The window_size option keeps only the latest 5 segments with the default duration of 5 seconds.
ffmpeg -re -i <input> -map 0 -map 0 -c:a libfdk_aac -c:v libx264 \
-b:v:0 800k -profile:v:0 main \
-b:v:1 300k -s:v:1 320x170 -profile:v:1 baseline -ar:a:1 22050 \
-bf 1 -keyint_min 120 -g 120 -sc_threshold 0 -b_strategy 0 \
-use_timeline 1 -use_template 1 -window_size 5 \
-adaptation_sets "id=0,streams=v id=1,streams=a" \
-f dash /path/to/out.mpd
daud
D-Cinema audio muxer.
It accepts a single 6-channels audio stream resampled at 96000 Hz encoded with the pcm_24daud codec.
Example
Use ffmpeg to mux input audio to a 5.1 channel layout resampled at 96000Hz:
ffmpeg -i INPUT -af aresample=96000,pan=5.1 slow.302
For ffmpeg versions before 7.0 you might have to use the asetnsamples filter to limit the muxed packet
size, because this format does not support muxing packets larger than 65535 bytes (3640 samples). For
newer ffmpeg versions audio is automatically packetized to 36000 byte (2000 sample) packets.
dv
DV (Digital Video) muxer.
It accepts exactly one dvvideo video stream and at most two pcm_s16 audio streams. More constraints are
defined by the property of the video, which must correspond to a DV video supported profile, and on the
framerate.
Example
Use ffmpeg to convert the input:
ffmpeg -i INPUT -s:v 720x480 -pix_fmt yuv411p -r 29.97 -ac 2 -ar 48000 -y out.dv
ffmetadata
FFmpeg metadata muxer.
This muxer writes the streams metadata in the ffmetadata format.
See the Metadata chapter for information about the format.
Example
Use ffmpeg to extract metadata from an input file to a metadata.ffmeta file in ffmetadata format:
ffmpeg -i INPUT -f ffmetadata metadata.ffmeta
fifo
FIFO (First-In First-Out) muxer.
The fifo pseudo-muxer allows the separation of encoding and muxing by using a first-in-first-out queue
and running the actual muxer in a separate thread.
This is especially useful in combination with the tee muxer and can be used to send data to several
destinations with different reliability/writing speed/latency.
The target muxer is either selected from the output name or specified through the fifo_format option.
The behavior of the fifo muxer if the queue fills up or if the output fails (e.g. if a packet cannot be
written to the output) is selectable:
• Output can be transparently restarted with configurable delay between retries based on real time or
time of the processed stream.
• Encoding can be blocked during temporary failure, or continue transparently dropping packets in case
the FIFO queue fills up.
API users should be aware that callback functions ("interrupt_callback", "io_open" and "io_close") used
within its "AVFormatContext" must be thread-safe.
Options
attempt_recovery bool
If failure occurs, attempt to recover the output. This is especially useful when used with network
output, since it makes it possible to restart streaming transparently. By default this option is set
to "false".
drop_pkts_on_overflow bool
If set to "true", in case the fifo queue fills up, packets will be dropped rather than blocking the
encoder. This makes it possible to continue streaming without delaying the input, at the cost of
omitting part of the stream. By default this option is set to "false", so in such cases the encoder
will be blocked until the muxer processes some of the packets and none of them is lost.
fifo_format format_name
Specify the format name. Useful if it cannot be guessed from the output name suffix.
format_opts options
Specify format options for the underlying muxer. Muxer options can be specified as a list of
key=value pairs separated by ':'.
max_recovery_attempts count
Set maximum number of successive unsuccessful recovery attempts after which the output fails
permanently. By default this option is set to 0 (unlimited).
queue_size size
Specify size of the queue as a number of packets. Default value is 60.
recover_any_error bool
If set to "true", recovery will be attempted regardless of type of the error causing the failure. By
default this option is set to "false" and in case of certain (usually permanent) errors the recovery
is not attempted even when the attempt_recovery option is set to "true".
recovery_wait_streamtime bool
If set to "false", the real time is used when waiting for the recovery attempt (i.e. the recovery
will be attempted after the time specified by the recovery_wait_time option).
If set to "true", the time of the processed stream is taken into account instead (i.e. the recovery
will be attempted after discarding the packets corresponding to the recovery_wait_time option).
By default this option is set to "false".
recovery_wait_time duration
Specify waiting time in seconds before the next recovery attempt after previous unsuccessful recovery
attempt. Default value is 5.
restart_with_keyframe bool
Specify whether to wait for the keyframe after recovering from queue overflow or failure. This option
is set to "false" by default.
timeshift duration
Buffer the specified amount of packets and delay writing the output. Note that the value of the
queue_size option must be big enough to store the packets for timeshift. At the end of the input the
fifo buffer is flushed at realtime speed.
Example
Use ffmpeg to stream to an RTMP server, continue processing the stream at real-time rate even in case of
temporary failure (network outage) and attempt to recover streaming every second indefinitely:
ffmpeg -re -i ... -c:v libx264 -c:a aac -f fifo -fifo_format flv \
-drop_pkts_on_overflow 1 -attempt_recovery 1 -recovery_wait_time 1 \
-map 0:v -map 0:a rtmp://example.com/live/stream_name
film_cpk
Sega film (.cpk) muxer.
This format was used as internal format for several Sega games.
For more information regarding the Sega film file format, visit
<http://wiki.multimedia.cx/index.php?title=Sega_FILM>.
It accepts at maximum one cinepak or raw video stream, and at maximum one audio stream.
filmstrip
Adobe Filmstrip muxer.
This format is used by several Adobe tools to store a generated filmstrip export. It accepts a single raw
video stream.
fits
Flexible Image Transport System (FITS) muxer.
This image format is used to store astronomical data.
For more information regarding the format, visit <https://fits.gsfc.nasa.gov>.
flac
Raw FLAC audio muxer.
This muxer accepts exactly one FLAC audio stream. Additionally, it is possible to add images with
disposition attached_pic.
Options
write_header bool
write the file header if set to "true", default is "true"
Example
Use ffmpeg to store the audio stream from an input file, together with several pictures used with
attached_pic disposition:
ffmpeg -i INPUT -i pic1.png -i pic2.jpg -map 0:a -map 1 -map 2 -disposition:v attached_pic OUTPUT
flv
Adobe Flash Video Format muxer.
Options
flvflags flags
Possible values:
aac_seq_header_detect
Place AAC sequence header based on audio stream data.
no_sequence_end
Disable sequence end tag.
no_metadata
Disable metadata tag.
no_duration_filesize
Disable duration and filesize in metadata when they are equal to zero at the end of stream. (Be
used to non-seekable living stream).
add_keyframe_index
Used to facilitate seeking; particularly for HTTP pseudo streaming.
framecrc
Per-packet CRC (Cyclic Redundancy Check) testing format.
This muxer computes and prints the Adler-32 CRC for each audio and video packet. By default audio frames
are converted to signed 16-bit raw audio and video frames to raw video before computing the CRC.
The output of the muxer consists of a line for each audio and video packet of the form:
<stream_index>, <packet_dts>, <packet_pts>, <packet_duration>, <packet_size>, 0x<CRC>
CRC is a hexadecimal number 0-padded to 8 digits containing the CRC of the packet.
Examples
For example to compute the CRC of the audio and video frames in INPUT, converted to raw audio and video
packets, and store it in the file out.crc:
ffmpeg -i INPUT -f framecrc out.crc
To print the information to stdout, use the command:
ffmpeg -i INPUT -f framecrc -
With ffmpeg, you can select the output format to which the audio and video frames are encoded before
computing the CRC for each packet by specifying the audio and video codec. For example, to compute the
CRC of each decoded input audio frame converted to PCM unsigned 8-bit and of each decoded input video
frame converted to MPEG-2 video, use the command:
ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -
See also the crc muxer.
framehash
Per-packet hash testing format.
This muxer computes and prints a cryptographic hash for each audio and video packet. This can be used for
packet-by-packet equality checks without having to individually do a binary comparison on each.
By default audio frames are converted to signed 16-bit raw audio and video frames to raw video before
computing the hash, but the output of explicit conversions to other codecs can also be used. It uses the
SHA-256 cryptographic hash function by default, but supports several other algorithms.
The output of the muxer consists of a line for each audio and video packet of the form:
<stream_index>, <packet_dts>, <packet_pts>, <packet_duration>, <packet_size>, <hash>
hash is a hexadecimal number representing the computed hash for the packet.
hash algorithm
Use the cryptographic hash function specified by the string algorithm. Supported values include
"MD5", "murmur3", "RIPEMD128", "RIPEMD160", "RIPEMD256", "RIPEMD320", "SHA160", "SHA224", "SHA256"
(default), "SHA512/224", "SHA512/256", "SHA384", "SHA512", "CRC32" and "adler32".
Examples
To compute the SHA-256 hash of the audio and video frames in INPUT, converted to raw audio and video
packets, and store it in the file out.sha256:
ffmpeg -i INPUT -f framehash out.sha256
To print the information to stdout, using the MD5 hash function, use the command:
ffmpeg -i INPUT -f framehash -hash md5 -
See also the hash muxer.
framemd5
Per-packet MD5 testing format.
This is a variant of the framehash muxer. Unlike that muxer, it defaults to using the MD5 hash function.
Examples
To compute the MD5 hash of the audio and video frames in INPUT, converted to raw audio and video packets,
and store it in the file out.md5:
ffmpeg -i INPUT -f framemd5 out.md5
To print the information to stdout, use the command:
ffmpeg -i INPUT -f framemd5 -
See also the framehash and md5 muxers.
gif
Animated GIF muxer.
Note that the GIF format has a very large time base: the delay between two frames can therefore not be
smaller than one centi second.
Options
loop bool
Set the number of times to loop the output. Use -1 for no loop, 0 for looping indefinitely (default).
final_delay delay
Force the delay (expressed in centiseconds) after the last frame. Each frame ends with a delay until
the next frame. The default is -1, which is a special value to tell the muxer to re-use the previous
delay. In case of a loop, you might want to customize this value to mark a pause for instance.
Example
Encode a gif looping 10 times, with a 5 seconds delay between the loops:
ffmpeg -i INPUT -loop 10 -final_delay 500 out.gif
Note 1: if you wish to extract the frames into separate GIF files, you need to force the image2 muxer:
ffmpeg -i INPUT -c:v gif -f image2 "out%d.gif"
gxf
General eXchange Format (GXF) muxer.
GXF was developed by Grass Valley Group, then standardized by SMPTE as SMPTE 360M and was extended in
SMPTE RDD 14-2007 to include high-definition video resolutions.
It accepts at most one video stream with codec mjpeg, or mpeg1video, or mpeg2video, or dvvideo with
resolution 512x480 or 608x576, and several audio streams with rate 48000Hz and codec pcm16_le.
hash
Hash testing format.
This muxer computes and prints a cryptographic hash of all the input audio and video frames. This can be
used for equality checks without having to do a complete binary comparison.
By default audio frames are converted to signed 16-bit raw audio and video frames to raw video before
computing the hash, but the output of explicit conversions to other codecs can also be used. Timestamps
are ignored. It uses the SHA-256 cryptographic hash function by default, but supports several other
algorithms.
The output of the muxer consists of a single line of the form: algo=hash, where algo is a short string
representing the hash function used, and hash is a hexadecimal number representing the computed hash.
hash algorithm
Use the cryptographic hash function specified by the string algorithm. Supported values include
"MD5", "murmur3", "RIPEMD128", "RIPEMD160", "RIPEMD256", "RIPEMD320", "SHA160", "SHA224", "SHA256"
(default), "SHA512/224", "SHA512/256", "SHA384", "SHA512", "CRC32" and "adler32".
Examples
To compute the SHA-256 hash of the input converted to raw audio and video, and store it in the file
out.sha256:
ffmpeg -i INPUT -f hash out.sha256
To print an MD5 hash to stdout use the command:
ffmpeg -i INPUT -f hash -hash md5 -
See also the framehash muxer.
hds
HTTP Dynamic Streaming (HDS) muxer.
HTTP dynamic streaming, or HDS, is an adaptive bitrate streaming method developed by Adobe. HDS delivers
MP4 video content over HTTP connections. HDS can be used for on-demand streaming or live streaming.
This muxer creates an .f4m (Adobe Flash Media Manifest File) manifest, an .abst (Adobe Bootstrap File)
for each stream, and segment files in a directory specified as the output.
These needs to be accessed by an HDS player throuhg HTTPS for it to be able to perform playback on the
generated stream.
Options
extra_window_size int
number of fragments kept outside of the manifest before removing from disk
min_frag_duration microseconds
minimum fragment duration (in microseconds), default value is 1 second (10000000)
remove_at_exit bool
remove all fragments when finished when set to "true"
window_size int
number of fragments kept in the manifest, if set to a value different from 0. By default all segments
are kept in the output directory.
Example
Use ffmpeg to generate HDS files to the output.hds directory in real-time rate:
ffmpeg -re -i INPUT -f hds -b:v 200k output.hds
hls
Apple HTTP Live Streaming muxer that segments MPEG-TS according to the HTTP Live Streaming (HLS)
specification.
It creates a playlist file, and one or more segment files. The output filename specifies the playlist
filename.
By default, the muxer creates a file for each segment produced. These files have the same name as the
playlist, followed by a sequential number and a .ts extension.
Make sure to require a closed GOP when encoding and to set the GOP size to fit your segment time
constraint.
For example, to convert an input file with ffmpeg:
ffmpeg -i in.mkv -c:v h264 -flags +cgop -g 30 -hls_time 1 out.m3u8
This example will produce the playlist, out.m3u8, and segment files: out0.ts, out1.ts, out2.ts, etc.
See also the segment muxer, which provides a more generic and flexible implementation of a segmenter, and
can be used to perform HLS segmentation.
Options
This muxer supports the following options:
hls_init_time duration
Set the initial target segment length. Default value is 0.
duration must be a time duration specification, see the Time duration section in the ffmpeg-utils(1)
manual.
Segment will be cut on the next key frame after this time has passed on the first m3u8 list. After
the initial playlist is filled ffmpeg will cut segments at duration equal to "hls_time"
hls_time duration
Set the target segment length. Default value is 2.
duration must be a time duration specification, see the Time duration section in the ffmpeg-utils(1)
manual. Segment will be cut on the next key frame after this time has passed.
hls_list_size size
Set the maximum number of playlist entries. If set to 0 the list file will contain all the segments.
Default value is 5.
hls_delete_threshold size
Set the number of unreferenced segments to keep on disk before "hls_flags delete_segments" deletes
them. Increase this to allow continue clients to download segments which were recently referenced in
the playlist. Default value is 1, meaning segments older than "hls_list_size+1" will be deleted.
hls_start_number_source
Start the playlist sequence number ("#EXT-X-MEDIA-SEQUENCE") according to the specified source.
Unless "hls_flags single_file" is set, it also specifies source of starting sequence numbers of
segment and subtitle filenames. In any case, if "hls_flags append_list" is set and read playlist
sequence number is greater than the specified start sequence number, then that value will be used as
start value.
It accepts the following values:
generic (default)
Set the starting sequence numbers according to start_number option value.
epoch
The start number will be the seconds since epoch (1970-01-01 00:00:00)
epoch_us
The start number will be the microseconds since epoch (1970-01-01 00:00:00)
datetime
The start number will be based on the current date/time as YYYYmmddHHMMSS. e.g. 20161231235759.
start_number number
Start the playlist sequence number ("#EXT-X-MEDIA-SEQUENCE") from the specified number when
hls_start_number_source value is generic. (This is the default case.) Unless "hls_flags single_file"
is set, it also specifies starting sequence numbers of segment and subtitle filenames. Default value
is 0.
hls_allow_cache allowcache
Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments.
hls_base_url baseurl
Append baseurl to every entry in the playlist. Useful to generate playlists with absolute paths.
Note that the playlist sequence number must be unique for each segment and it is not to be confused
with the segment filename sequence number which can be cyclic, for example if the wrap option is
specified.
hls_segment_filename filename
Set the segment filename. Unless "hls_flags single_file" is set, filename is used as a string format
with the segment number:
ffmpeg -i in.nut -hls_segment_filename 'file%03d.ts' out.m3u8
This example will produce the playlist, out.m3u8, and segment files: file000.ts, file001.ts,
file002.ts, etc.
filename may contain full path or relative path specification, but only the file name part without
any path info 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", this string specifies the position of variant stream index in the generated segment file
names.
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
This example 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.
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
This example will produce the playlists segment file sets: vs0/file_000.ts, vs0/file_001.ts,
vs0/file_002.ts, etc. and vs1/file_000.ts, vs1/file_001.ts, vs1/file_002.ts, etc.
strftime
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 specify second_level_segment_index hls_flag and
%%d will be the specifier.
ffmpeg -i in.nut -strftime 1 -hls_segment_filename 'file-%Y%m%d-%s.ts' out.m3u8
This example 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.
ffmpeg -i in.nut -strftime 1 -hls_flags second_level_segment_index -hls_segment_filename 'file-%Y%m%d-%%04d.ts' out.m3u8
This example will produce the playlist, out.m3u8, and segment files: file-20160215-0001.ts,
file-20160215-0002.ts, etc.
strftime_mkdir
Used together with -strftime_mkdir, it will create all subdirectories which is expanded in filename.
ffmpeg -i in.nut -strftime 1 -strftime_mkdir 1 -hls_segment_filename '%Y%m%d/file-%Y%m%d-%s.ts' out.m3u8
This example 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.
ffmpeg -i in.nut -strftime 1 -strftime_mkdir 1 -hls_segment_filename '%Y/%m/%d/file-%Y%m%d-%s.ts' out.m3u8
This example will create a directory hierarchy 2016/02/15 (if any of them do not exist), and then
produce the playlist, out.m3u8, and segment files: 2016/02/15/file-20160215-1455569023.ts,
2016/02/15/file-20160215-1455569024.ts, etc.
hls_segment_options options_list
Set output format options using a :-separated list of key=value parameters. Values containing ":"
special characters must be escaped.
hls_key_info_file key_info_file
Use the information in key_info_file for segment encryption. The first line of key_info_file
specifies the key URI written to the playlist. The key URL is used to access the encryption key
during playback. The second line specifies the path to the key file used to obtain the key during the
encryption process. The key file is read as a single packed array of 16 octets in binary format. The
optional third line specifies the initialization vector (IV) as a hexadecimal string to be used
instead of the segment sequence number (default) for encryption. Changes to key_info_file will result
in segment encryption with the new key/IV and an entry in the playlist for the new key URI/IV if
"hls_flags periodic_rekey" is enabled.
Key info file format:
<key URI>
<key file path>
<IV> (optional)
Example key URIs:
http://server/file.key
/path/to/file.key
file.key
Example key file paths:
file.key
/path/to/file.key
Example IV:
0123456789ABCDEF0123456789ABCDEF
Key info file example:
http://server/file.key
/path/to/file.key
0123456789ABCDEF0123456789ABCDEF
Example shell script:
#!/bin/sh
BASE_URL=${1:-'.'}
openssl rand 16 > file.key
echo $BASE_URL/file.key > file.keyinfo
echo file.key >> file.keyinfo
echo $(openssl rand -hex 16) >> file.keyinfo
ffmpeg -f lavfi -re -i testsrc -c:v h264 -hls_flags delete_segments \
-hls_key_info_file file.keyinfo out.m3u8
-hls_enc enc
Enable (1) or disable (0) the AES128 encryption. When enabled every segment generated is encrypted
and the encryption key is saved as playlist name.key.
-hls_enc_key key
16-octet key to encrypt the segments, by default it is randomly generated.
-hls_enc_key_url keyurl
If set, keyurl is prepended instead of baseurl to the key filename in the playlist.
-hls_enc_iv iv
16-octet initialization vector for every segment instead of the autogenerated ones.
hls_segment_type flags
Possible values:
mpegts
Output segment files in MPEG-2 Transport Stream format. This is compatible with all HLS versions.
fmp4
Output segment files in fragmented MP4 format, similar to MPEG-DASH. fmp4 files may be used in
HLS version 7 and above.
hls_fmp4_init_filename filename
Set filename to the fragment files header file, default filename is init.mp4.
Use "-strftime 1" on filename to expand the segment filename with localtime.
ffmpeg -i in.nut -hls_segment_type fmp4 -strftime 1 -hls_fmp4_init_filename "%s_init.mp4" out.m3u8
This will produce init like this 1602678741_init.mp4
hls_fmp4_init_resend
Resend init file after m3u8 file refresh every time, default is 0.
When "var_stream_map" is set with two or more variant streams, the filename pattern must contain the
string "%v", this string specifies the position of variant stream index in the generated init file
names. The string "%v" may be present in the filename or in the last directory name containing the
file. If the string is present in the directory name, then sub-directories are created after
expanding the directory name pattern. This enables creation of init files corresponding to different
variant streams in subdirectories.
hls_flags flags
Possible values:
single_file
If this flag is set, the muxer will store all segments in a single MPEG-TS file, and will use
byte ranges in the playlist. HLS playlists generated with this way will have the version number
4. For example:
ffmpeg -i in.nut -hls_flags single_file out.m3u8
Will produce the playlist, out.m3u8, and a single segment file, out.ts.
delete_segments
Segment files removed from the playlist are deleted after a period of time equal to the duration
of the segment plus the duration of the playlist.
append_list
Append new segments into the end of old segment list, and remove the "#EXT-X-ENDLIST" from the
old segment list.
round_durations
Round the duration info in the playlist file segment info to integer values, instead of using
floating point. If there are no other features requiring higher HLS versions be used, then this
will allow ffmpeg to output a HLS version 2 m3u8.
discont_start
Add the "#EXT-X-DISCONTINUITY" tag to the playlist, before the first segment's information.
omit_endlist
Do not append the "EXT-X-ENDLIST" tag at the end of the playlist.
periodic_rekey
The file specified by "hls_key_info_file" will be checked periodically and detect updates to the
encryption info. Be sure to replace this file atomically, including the file containing the AES
encryption key.
independent_segments
Add the "#EXT-X-INDEPENDENT-SEGMENTS" 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" 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 keyframes. This improves behavior on some players
when the time between keyframes is inconsistent, but may make things worse on others, and can
cause some oddities during seeking. This flag should be used with the "hls_time" option.
program_date_time
Generate "EXT-X-PROGRAM-DATE-TIME" tags.
second_level_segment_index
Makes it possible to use segment indexes as %%d in hls_segment_filename expression besides
date/time values when strftime is on. To get fixed width numbers with trailing zeroes, %%0xd
format is available where x is the required width.
second_level_segment_size
Makes it possible to use segment sizes (counted in bytes) as %%s in hls_segment_filename
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
Makes it possible to use segment duration (calculated in microseconds) as %%t in
hls_segment_filename 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.
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
This 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 written into
temporary file and renamed after they are complete, similarly as segments are handled. But
playlists with "file" protocol and with type ("hls_playlist_type") other than "vod" are always
written into temporary file regardless of this flag. Master playlist files ("master_pl_name"), if
any, with "file" protocol, are always written into temporary file regardless of this flag if
"master_pl_publish_rate" value is other than zero.
hls_playlist_type event
Emit "#EXT-X-PLAYLIST-TYPE:EVENT" in the m3u8 header. Forces hls_list_size to 0; the playlist can
only be appended to.
hls_playlist_type vod
Emit "#EXT-X-PLAYLIST-TYPE:VOD" in the m3u8 header. Forces hls_list_size to 0; the playlist must not
change.
method
Use the given HTTP method to create the hls files.
ffmpeg -re -i in.ts -f hls -method PUT http://example.com/live/out.m3u8
This example will upload all the mpegts segment files to the HTTP server using the HTTP PUT method,
and update the m3u8 files every "refresh" times using the same method. Note that the HTTP server
must support the given method for uploading files.
http_user_agent
Override User-Agent field in HTTP header. Applicable only for HTTP output.
var_stream_map
Map string which specifies 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.
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
This example creates 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. If you want something meaningful text instead of indexes in result
names, you may specify names for each or some of the variants as in the following example.
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
This example creates 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 \
-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
This example creates 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 -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
This example creates 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: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
This example creates 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, #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 \
-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
This example creates 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, #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,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
This example creates 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, #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 -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
This example adds "#EXT-X-MEDIA" tag with "TYPE=SUBTITLES" in the master playlist with webvtt
subtitle group name 'subtitle'. Please make sure the input file has one text subtitle stream at
least.
cc_stream_map
Map string which specifies different closed captions groups and their attributes. The closed captions
stream groups are separated by space. Expected string format is like this "ccgroup:<group
name>,instreamid:<INSTREAM-ID>,language:<language code> ....". 'ccgroup' and 'instreamid' are
mandatory attributes. 'language' is an optional attribute. The closed captions groups configured
using this option are mapped to different variant streams by providing the same 'ccgroup' name in the
"var_stream_map" string. If "var_stream_map" is not set, then the first available ccgroup in
"cc_stream_map" is mapped to the output variant stream. The examples for these two use cases are
given below.
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 example adds "#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 adds "CLOSED-CAPTIONS" attribute
with group name 'cc' for the output variant stream.
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
This example adds two "#EXT-X-MEDIA" tags with "TYPE=CLOSED-CAPTIONS" in the master playlist for the
INSTREAM-IDs 'CC1' and 'CC2'. Also, it adds "CLOSED-CAPTIONS" attribute with group name 'cc' for the
two output variant streams.
master_pl_name
Create HLS master playlist with the given name.
ffmpeg -re -i in.ts -f hls -master_pl_name master.m3u8 http://example.com/live/out.m3u8
This example creates HLS master playlist with name master.m3u8 and it is published at
http://example.com/live/
master_pl_publish_rate
Publish master play list repeatedly every after specified number of segment intervals.
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
This example creates HLS master playlist with name master.m3u8 and keep publishing it repeatedly
every after 30 segments i.e. every after 60s.
http_persistent
Use persistent HTTP connections. Applicable only for HTTP output.
timeout
Set timeout for socket I/O operations. Applicable only for HTTP output.
ignore_io_errors
Ignore IO errors during open, write and delete. Useful for long-duration runs with network output.
headers
Set custom HTTP headers, can override built in default headers. Applicable only for HTTP output.
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
image2
Image file muxer.
The image file 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.
Options
frame_pts
If set to 1, expand the filename with pts from pkt->pts. Default value is 0.
start_number
Start the sequence from the specified number. Default value is 1.
update
If set to 1, the filename will always be interpreted as just a filename, not a pattern, and the
corresponding file will be continuously overwritten with new images. Default value is 0.
strftime
If set to 1, expand the filename with date and time information from strftime(). Default value is 0.
atomic_writing
Write output to a temporary file, which is renamed to target filename once writing is completed.
Default is disabled.
protocol_opts options_list
Set protocol options as a :-separated list of key=value parameters. Values containing the ":" special
character must be escaped.
Examples
The following example shows how to 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.
For example 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"
You can 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
A more complex example is to publish contents of your desktop directly to a WebDAV server every second:
ffmpeg -f x11grab -framerate 1 -i :0.0 -q:v 6 -update 1 -protocol_opts method=PUT http://example.com/desktop.jpg
matroska
Matroska container muxer.
This muxer implements the matroska and webm container specs.
Metadata
The recognized metadata settings in this muxer are:
title
Set title name provided to a single track. This gets mapped to the FileDescription element for a
stream written as attachment.
language
Specify the language of the track in the Matroska languages form.
The language can be either the 3 letters bibliographic ISO-639-2 (ISO 639-2/B) form (like "fre" for
French), or a language code mixed with a country code for specialities in languages (like "fre-ca"
for Canadian French).
stereo_mode
Set stereo 3D video layout of two views in a single video track.
The following values are recognized:
mono
video is not stereo
left_right
Both views are arranged side by side, Left-eye view is on the left
bottom_top
Both views are arranged in top-bottom orientation, Left-eye view is at bottom
top_bottom
Both views are arranged in top-bottom orientation, Left-eye view is on top
checkerboard_rl
Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first
checkerboard_lr
Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first
row_interleaved_rl
Each view is constituted by a row based interleaving, Right-eye view is first row
row_interleaved_lr
Each view is constituted by a row based interleaving, Left-eye view is first row
col_interleaved_rl
Both views are arranged in a column based interleaving manner, Right-eye view is first column
col_interleaved_lr
Both views are arranged in a column based interleaving manner, Left-eye view is first column
anaglyph_cyan_red
All frames are in anaglyph format viewable through red-cyan filters
right_left
Both views are arranged side by side, Right-eye view is on the left
anaglyph_green_magenta
All frames are in anaglyph format viewable through green-magenta filters
block_lr
Both eyes laced in one Block, Left-eye view is first
block_rl
Both eyes laced in one Block, Right-eye view is first
For example a 3D WebM clip can be created using the following command line:
ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm
Options
This muxer supports the following options:
reserve_index_space
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 a given amount of space in the file
header and then try to write the cues there when the muxing finishes. If the reserved space does not
suffice, no Cues will be written, the file will be finalized and writing the trailer will return an
error. A safe size for most use cases should be about 50kB per hour of video.
Note that cues are only written if the output is seekable and this option will have no effect if it
is not.
cues_to_front
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.
default_mode
This option controls 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.
flipped_raw_rgb
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.
md5
MD5 testing format.
This is a variant of the hash muxer. Unlike that muxer, it defaults to using the MD5 hash function.
Examples
To compute the MD5 hash of the input converted to raw audio and video, and store it in the file out.md5:
ffmpeg -i INPUT -f md5 out.md5
You can print the MD5 to stdout with the command:
ffmpeg -i INPUT -f md5 -
See also the hash and framemd5 muxers.
mp3
The MP3 muxer writes a raw MP3 stream with the following optional features:
• An ID3v2 metadata header at the beginning (enabled by default). Versions 2.3 and 2.4 are supported,
the "id3v2_version" private option controls which one is used (3 or 4). Setting "id3v2_version" to 0
disables the ID3v2 header completely.
The muxer supports writing attached pictures (APIC frames) to the ID3v2 header. The pictures are
supplied to the muxer in form of a video stream with a single packet. There can be any number of
those streams, each will correspond to a single APIC frame. The stream metadata tags title and
comment map to APIC description and picture type respectively. See <http://id3.org/id3v2.4.0-frames>
for allowed picture types.
Note that the APIC frames must be written at the beginning, so the muxer will buffer the audio frames
until it gets all the pictures. It is therefore advised to provide the pictures as soon as possible
to avoid excessive buffering.
• A Xing/LAME frame right after the ID3v2 header (if present). It is enabled by default, but will be
written only if the output is seekable. The "write_xing" private option can be used to disable it.
The frame contains various information that may be useful to the decoder, like the audio duration or
encoder delay.
• A legacy ID3v1 tag at the end of the file (disabled by default). It may be enabled with the
"write_id3v1" private option, but as its capabilities are very limited, its usage is not recommended.
Examples:
Write an mp3 with an ID3v2.3 header and an ID3v1 footer:
ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3
To attach a picture to an mp3 file select both the audio and the picture stream with "map":
ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1
-metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3
Write a "clean" MP3 without any extra features:
ffmpeg -i input.wav -write_xing 0 -id3v2_version 0 out.mp3
mpegts
MPEG transport stream muxer.
This muxer implements ISO 13818-1 and part of ETSI EN 300 468.
The recognized metadata settings in mpegts muxer are "service_provider" and "service_name". If they are
not set the default for "service_provider" is FFmpeg and the default for "service_name" is Service01.
Options
The muxer options are:
mpegts_transport_stream_id integer
Set the transport_stream_id. This identifies a transponder in DVB. Default is 0x0001.
mpegts_original_network_id integer
Set the original_network_id. This is unique identifier of a network in DVB. Its main use is in the
unique identification of a service through the path Original_Network_ID, Transport_Stream_ID. Default
is 0x0001.
mpegts_service_id integer
Set the service_id, also known as program in DVB. Default is 0x0001.
mpegts_service_type integer
Set the program service_type. Default is "digital_tv". Accepts the following options:
hex_value
Any hexadecimal value between 0x01 and 0xff as defined in ETSI 300 468.
digital_tv
Digital TV service.
digital_radio
Digital Radio service.
teletext
Teletext service.
advanced_codec_digital_radio
Advanced Codec Digital Radio service.
mpeg2_digital_hdtv
MPEG2 Digital HDTV service.
advanced_codec_digital_sdtv
Advanced Codec Digital SDTV service.
advanced_codec_digital_hdtv
Advanced Codec Digital HDTV service.
mpegts_pmt_start_pid integer
Set the first PID for PMTs. Default is 0x1000, minimum is 0x0020, maximum is 0x1ffa. This option has
no effect in m2ts mode where the PMT PID is fixed 0x0100.
mpegts_start_pid integer
Set the first PID for elementary streams. Default is 0x0100, minimum is 0x0020, maximum is 0x1ffa.
This option has no effect in m2ts mode where the elementary stream PIDs are fixed.
mpegts_m2ts_mode boolean
Enable m2ts mode if set to 1. Default value is -1 which disables m2ts mode.
muxrate integer
Set a constant muxrate. Default is VBR.
pes_payload_size integer
Set minimum PES packet payload in bytes. Default is 2930.
mpegts_flags flags
Set mpegts flags. Accepts the following options:
resend_headers
Reemit PAT/PMT before writing the next packet.
latm
Use LATM packetization for AAC.
pat_pmt_at_frames
Reemit PAT and PMT at each video frame.
system_b
Conform to System B (DVB) instead of System A (ATSC).
initial_discontinuity
Mark the initial packet of each stream as discontinuity.
nit Emit NIT table.
omit_rai
Disable writing of random access indicator.
mpegts_copyts boolean
Preserve original timestamps, if value is set to 1. Default value is -1, which results in shifting
timestamps so that they start from 0.
omit_video_pes_length boolean
Omit the PES packet length for video packets. Default is 1 (true).
pcr_period integer
Override the default PCR retransmission time in milliseconds. Default is -1 which means that the PCR
interval will be determined automatically: 20 ms is used for CBR streams, the highest multiple of the
frame duration which is less than 100 ms is used for VBR streams.
pat_period duration
Maximum time in seconds between PAT/PMT tables. Default is 0.1.
sdt_period duration
Maximum time in seconds between SDT tables. Default is 0.5.
nit_period duration
Maximum time in seconds between NIT tables. Default is 0.5.
tables_version integer
Set PAT, PMT, SDT and NIT version (default 0, valid values are from 0 to 31, inclusively). This
option allows updating stream structure so that standard consumer may detect the change. To do so,
reopen output "AVFormatContext" (in case of API usage) or restart ffmpeg instance, cyclically
changing tables_version value:
ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
...
ffmpeg -i source3.ts -codec copy -f mpegts -tables_version 31 udp://1.1.1.1:1111
ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
...
Example
ffmpeg -i file.mpg -c copy \
-mpegts_original_network_id 0x1122 \
-mpegts_transport_stream_id 0x3344 \
-mpegts_service_id 0x5566 \
-mpegts_pmt_start_pid 0x1500 \
-mpegts_start_pid 0x150 \
-metadata service_provider="Some provider" \
-metadata service_name="Some Channel" \
out.ts
mxf, mxf_d10, mxf_opatom
MXF muxer.
Options
The muxer options are:
store_user_comments bool
Set if user comments should be stored if available or never. IRT D-10 does not allow user comments.
The default is thus to write them for mxf and mxf_opatom but not for mxf_d10
null
Null muxer.
This muxer does not generate any output file, it is mainly useful for testing or benchmarking purposes.
For example to benchmark decoding with ffmpeg you can use the command:
ffmpeg -benchmark -i INPUT -f null out.null
Note that the above command does not read or write the out.null file, but specifying the output file is
required by the ffmpeg syntax.
Alternatively you can write the command as:
ffmpeg -benchmark -i INPUT -f null -
nut
-syncpoints flags
Change the syncpoint usage in nut:
default use the normal low-overhead seeking aids.
none do not use the syncpoints at all, reducing the overhead but making the stream non-seekable;
Use of this option is not recommended, as the resulting files are very damage
sensitive and seeking is not possible. Also in general the overhead from
syncpoints is negligible. Note, -C<write_index> 0 can be used to disable
all growing data tables, allowing to mux endless streams with limited memory
and without these disadvantages.
timestamped extend the syncpoint with a wallclock field.
The none and timestamped flags are experimental.
-write_index bool
Write index at the end, the default is to write an index.
ffmpeg -i INPUT -f_strict experimental -syncpoints none - | processor
ogg
Ogg container muxer.
-page_duration duration
Preferred page duration, in microseconds. The muxer will attempt to create pages that are
approximately duration microseconds long. This allows the user to compromise between seek granularity
and container overhead. The default is 1 second. A value of 0 will fill all segments, making pages as
large as possible. A value of 1 will effectively use 1 packet-per-page in most situations, giving a
small seek granularity at the cost of additional container overhead.
-serial_offset value
Serial value from which to set the streams serial number. Setting it to different and sufficiently
large values ensures that the produced ogg files can be safely chained.
rcwt
Raw Captions With Time (RCWT) is a format native to ccextractor, a commonly used open source tool for
processing 608/708 closed caption (CC) sources. It can be used to archive the original, raw CC bitstream
and to produce a source file for later CC processing or conversion. As a result, it also allows for
interopability with ccextractor for processing CC data extracted via ffmpeg. The format is simple to
parse and can be used to retain all lines and variants of CC.
This muxer implements the specification as of 2024-01-05, which has been stable and unchanged for 10
years as of this writing.
This muxer will have some nuances from the way that ccextractor muxes RCWT. No compatibility issues when
processing the output with ccextractor have been observed as a result of this so far, but mileage may
vary and outputs will not be a bit-exact match.
A free specification of RCWT can be found here:
<https://github.com/CCExtractor/ccextractor/blob/master/docs/BINARY_FILE_FORMAT.TXT>
segment, stream_segment, ssegment
Basic stream segmenter.
This muxer outputs streams to a number of separate files of nearly fixed duration. Output filename
pattern can be set in a fashion similar to image2, or by using a "strftime" template if the strftime
option is enabled.
"stream_segment" is a variant of the muxer used to write to streaming output formats, i.e. which do not
require global headers, and is recommended for outputting e.g. to MPEG transport stream segments.
"ssegment" is a shorter alias for "stream_segment".
Every segment starts with a keyframe of the selected reference stream, which is set through the
reference_stream option.
Note that if you want accurate splitting for a video file, you need to make the input key frames
correspond to the exact splitting times expected by the segmenter, or the segment muxer will start the
new segment with the key frame found next after the specified start time.
The segment muxer works best with a single constant frame rate video.
Optionally it can generate a list of the created segments, by setting the option segment_list. The list
type is specified by the segment_list_type option. The entry filenames in the segment list are set by
default to the basename of the corresponding segment files.
See also the hls muxer, which provides a more specific implementation for HLS segmentation.
Options
The segment muxer supports the following options:
increment_tc 1|0
if set to 1, increment timecode between each segment If this is selected, the input need to have a
timecode in the first video stream. Default value is 0.
reference_stream specifier
Set the reference stream, as specified by the string specifier. If specifier is set to "auto", the
reference is chosen automatically. Otherwise it must be a stream specifier (see the ``Stream
specifiers'' chapter in the ffmpeg manual) which specifies the reference stream. The default value is
"auto".
segment_format format
Override the inner container format, by default it is guessed by the filename extension.
segment_format_options options_list
Set output format options using a :-separated list of key=value parameters. Values containing the ":"
special character must be escaped.
segment_list name
Generate also a listfile named name. If not specified no listfile is generated.
segment_list_flags flags
Set flags affecting the segment list generation.
It currently supports the following flags:
cache
Allow caching (only affects M3U8 list files).
live
Allow live-friendly file generation.
segment_list_size size
Update the list file so that it contains at most size segments. If 0 the list file will contain all
the segments. Default value is 0.
segment_list_entry_prefix prefix
Prepend prefix to each entry. Useful to generate absolute paths. By default no prefix is applied.
segment_list_type type
Select the listing format.
The following values are recognized:
flat
Generate a flat list for the created segments, one segment per line.
csv, ext
Generate a list for the created segments, one segment per line, each line matching the format
(comma-separated values):
<segment_filename>,<segment_start_time>,<segment_end_time>
segment_filename is the name of the output file generated by the muxer according to the provided
pattern. CSV escaping (according to RFC4180) is applied if required.
segment_start_time and segment_end_time specify the segment start and end time expressed in
seconds.
A list file with the suffix ".csv" or ".ext" will auto-select this format.
ext is deprecated in favor or csv.
ffconcat
Generate an ffconcat file for the created segments. The resulting file can be read using the
FFmpeg concat demuxer.
A list file with the suffix ".ffcat" or ".ffconcat" will auto-select this format.
m3u8
Generate an extended M3U8 file, version 3, compliant with
<http://tools.ietf.org/id/draft-pantos-http-live-streaming>.
A list file with the suffix ".m3u8" will auto-select this format.
If not specified the type is guessed from the list file name suffix.
segment_time time
Set segment duration to time, the value must be a duration specification. Default value is "2". See
also the segment_times option.
Note that splitting may not be accurate, unless you force the reference stream key-frames at the
given time. See the introductory notice and the examples below.
min_seg_duration time
Set minimum segment duration to time, the value must be a duration specification. This prevents the
muxer ending segments at a duration below this value. Only effective with "segment_time". Default
value is "0".
segment_atclocktime 1|0
If set to "1" split at regular clock time intervals starting from 00:00 o'clock. The time value
specified in segment_time is used for setting the length of the splitting interval.
For example with segment_time set to "900" this makes it possible to create files at 12:00 o'clock,
12:15, 12:30, etc.
Default value is "0".
segment_clocktime_offset duration
Delay the segment splitting times with the specified duration when using segment_atclocktime.
For example with segment_time set to "900" and segment_clocktime_offset set to "300" this makes it
possible to create files at 12:05, 12:20, 12:35, etc.
Default value is "0".
segment_clocktime_wrap_duration duration
Force the segmenter to only start a new segment if a packet reaches the muxer within the specified
duration after the segmenting clock time. This way you can make the segmenter more resilient to
backward local time jumps, such as leap seconds or transition to standard time from daylight savings
time.
Default is the maximum possible duration which means starting a new segment regardless of the elapsed
time since the last clock time.
segment_time_delta delta
Specify the accuracy time when selecting the start time for a segment, expressed as a duration
specification. Default value is "0".
When delta is specified a key-frame will start a new segment if its PTS satisfies the relation:
PTS >= start_time - time_delta
This option is useful when splitting video content, which is always split at GOP boundaries, in case
a key frame is found just before the specified split time.
In particular may be used in combination with the ffmpeg option force_key_frames. The key frame times
specified by force_key_frames may not be set accurately because of rounding issues, with the
consequence that a key frame time may result set just before the specified time. For constant frame
rate videos a value of 1/(2*frame_rate) should address the worst case mismatch between the specified
time and the time set by force_key_frames.
segment_times times
Specify a list of split points. times contains a list of comma separated duration specifications, in
increasing order. See also the segment_time option.
segment_frames frames
Specify a list of split video frame numbers. frames contains a list of comma separated integer
numbers, in increasing order.
This option specifies to start a new segment whenever a reference stream key frame is found and the
sequential number (starting from 0) of the frame is greater or equal to the next value in the list.
segment_wrap limit
Wrap around segment index once it reaches limit.
segment_start_number number
Set the sequence number of the first segment. Defaults to 0.
strftime 1|0
Use the "strftime" function to define the name of the new segments to write. If this is selected, the
output segment name must contain a "strftime" function template. Default value is 0.
break_non_keyframes 1|0
If enabled, allow segments to start on frames other than keyframes. This improves behavior on some
players when the time between keyframes is inconsistent, but may make things worse on others, and can
cause some oddities during seeking. Defaults to 0.
reset_timestamps 1|0
Reset timestamps at the beginning of each segment, so that each segment will start with near-zero
timestamps. It is meant to ease the playback of the generated segments. May not work with some
combinations of muxers/codecs. It is set to 0 by default.
initial_offset offset
Specify timestamp offset to apply to the output packet timestamps. The argument must be a time
duration specification, and defaults to 0.
write_empty_segments 1|0
If enabled, write an empty segment if there are no packets during the period a segment would usually
span. Otherwise, the segment will be filled with the next packet written. Defaults to 0.
Make sure to require a closed GOP when encoding and to set the GOP size to fit your segment time
constraint.
Examples
• Remux the content of file in.mkv to a list of segments out-000.nut, out-001.nut, etc., and write the
list of generated segments to out.list:
ffmpeg -i in.mkv -codec hevc -flags +cgop -g 60 -map 0 -f segment -segment_list out.list out%03d.nut
• Segment input and set output format options for the output segments:
ffmpeg -i in.mkv -f segment -segment_time 10 -segment_format_options movflags=+faststart out%03d.mp4
• Segment the input file according to the split points specified by the segment_times option:
ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 out%03d.nut
• Use the ffmpeg force_key_frames option to force key frames in the input at the specified location,
together with the segment option segment_time_delta to account for possible roundings operated when
setting key frame times.
ffmpeg -i in.mkv -force_key_frames 1,2,3,5,8,13,21 -codec:v mpeg4 -codec:a pcm_s16le -map 0 \
-f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 -segment_time_delta 0.05 out%03d.nut
In order to force key frames on the input file, transcoding is required.
• Segment the input file by splitting the input file according to the frame numbers sequence specified
with the segment_frames option:
ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_frames 100,200,300,500,800 out%03d.nut
• Convert the in.mkv to TS segments using the "libx264" and "aac" encoders:
ffmpeg -i in.mkv -map 0 -codec:v libx264 -codec:a aac -f ssegment -segment_list out.list out%03d.ts
• Segment the input file, and create an M3U8 live playlist (can be used as live HLS source):
ffmpeg -re -i in.mkv -codec copy -map 0 -f segment -segment_list playlist.m3u8 \
-segment_list_flags +live -segment_time 10 out%03d.mkv
smoothstreaming
Smooth Streaming muxer generates a set of files (Manifest, chunks) suitable for serving with conventional
web server.
window_size
Specify the number of fragments kept in the manifest. Default 0 (keep all).
extra_window_size
Specify the number of fragments kept outside of the manifest before removing from disk. Default 5.
lookahead_count
Specify the number of lookahead fragments. Default 2.
min_frag_duration
Specify the minimum fragment duration (in microseconds). Default 5000000.
remove_at_exit
Specify whether to remove all fragments when finished. Default 0 (do not remove).
streamhash
Per stream hash testing format.
This muxer computes and prints a cryptographic hash of all the input frames, on a per-stream basis. This
can be used for equality checks without having to do a complete binary comparison.
By default audio frames are converted to signed 16-bit raw audio and video frames to raw video before
computing the hash, but the output of explicit conversions to other codecs can also be used. Timestamps
are ignored. It uses the SHA-256 cryptographic hash function by default, but supports several other
algorithms.
The output of the muxer consists of one line per stream of the form: streamindex,streamtype,algo=hash,
where streamindex is the index of the mapped stream, streamtype is a single character indicating the type
of stream, algo is a short string representing the hash function used, and hash is a hexadecimal number
representing the computed hash.
hash algorithm
Use the cryptographic hash function specified by the string algorithm. Supported values include
"MD5", "murmur3", "RIPEMD128", "RIPEMD160", "RIPEMD256", "RIPEMD320", "SHA160", "SHA224", "SHA256"
(default), "SHA512/224", "SHA512/256", "SHA384", "SHA512", "CRC32" and "adler32".
Examples
To compute the SHA-256 hash of the input converted to raw audio and video, and store it in the file
out.sha256:
ffmpeg -i INPUT -f streamhash out.sha256
To print an MD5 hash to stdout use the command:
ffmpeg -i INPUT -f streamhash -hash md5 -
See also the hash and framehash muxers.
tee
The tee muxer can be used to write the same data to several outputs, such as files or streams. It can be
used, for example, to stream a video over a network and save it to disk at the same time.
It is different from specifying several outputs to the ffmpeg command-line tool. With the tee muxer, the
audio and video data will be encoded only once. With conventional multiple outputs, multiple encoding
operations in parallel are initiated, which can be a very expensive process. The tee muxer is not useful
when using the libavformat API directly because it is then possible to feed the same packets to several
muxers directly.
Since the tee muxer does not represent any particular output format, ffmpeg cannot auto-select output
streams. So all streams intended for output must be specified using "-map". See the examples below.
Some encoders may need different options depending on the output format; the auto-detection of this can
not work with the tee muxer, so they need to be explicitly specified. The main example is the
global_header flag.
The slave outputs are specified in the file name given to the muxer, separated by '|'. If any of the
slave name contains the '|' separator, leading or trailing spaces or any special character, those must be
escaped (see the "Quoting and escaping" section in the ffmpeg-utils(1) manual).
Options
use_fifo bool
If set to 1, slave outputs will be processed in separate threads using the fifo muxer. This allows to
compensate for different speed/latency/reliability of outputs and setup transparent recovery. By
default this feature is turned off.
fifo_options
Options to pass to fifo pseudo-muxer instances. See fifo.
Muxer options can be specified for each slave by prepending them as a list of key=value pairs separated
by ':', between square brackets. If the options values contain a special character or the ':' separator,
they must be escaped; note that this is a second level escaping.
The following special options are also recognized:
f Specify the format name. Required if it cannot be guessed from the output URL.
bsfs[/spec]
Specify a list of bitstream filters to apply to the specified output.
It is possible to specify to which streams a given bitstream filter applies, by appending a stream
specifier to the option separated by "/". spec must be a stream specifier (see Format stream
specifiers).
If the stream specifier is not specified, the bitstream filters will be applied to all streams in the
output. This will cause that output operation to fail if the output contains streams to which the
bitstream filter cannot be applied e.g. "h264_mp4toannexb" being applied to an output containing an
audio stream.
Options for a bitstream filter must be specified in the form of "opt=value".
Several bitstream filters can be specified, separated by ",".
use_fifo bool
This allows to override tee muxer use_fifo option for individual slave muxer.
fifo_options
This allows to override tee muxer fifo_options for individual slave muxer. See fifo.
select
Select the streams that should be mapped to the slave output, specified by a stream specifier. If not
specified, this defaults to all the mapped streams. This will cause that output operation to fail if
the output format does not accept all mapped streams.
You may use multiple stream specifiers separated by commas (",") e.g.: "a:0,v"
onfail
Specify behaviour on output failure. This can be set to either "abort" (which is default) or
"ignore". "abort" will cause whole process to fail in case of failure on this slave output. "ignore"
will ignore failure on this output, so other outputs will continue without being affected.
Examples
• Encode something and both archive it in a WebM file and stream it as MPEG-TS over UDP:
ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
"archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
• As above, but continue streaming even if output to local file fails (for example local drive fills
up):
ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
"[onfail=ignore]archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
• Use ffmpeg to encode the input, and send the output to three different destinations. The "dump_extra"
bitstream filter is used to add extradata information to all the output video keyframes packets, as
requested by the MPEG-TS format. The select option is applied to out.aac in order to make it contain
only audio packets.
ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
-f tee "[bsfs/v=dump_extra=freq=keyframe]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac"
• As above, but select only stream "a:1" for the audio output. Note that a second level escaping must
be performed, as ":" is a special character used to separate options.
ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
-f tee "[bsfs/v=dump_extra=freq=keyframe]out.ts|[movflags=+faststart]out.mp4|[select=\'a:1\']out.aac"
webm_chunk
WebM Live Chunk Muxer.
This muxer writes out WebM headers and chunks as separate files which can be consumed by clients that
support WebM Live streams via DASH.
Options
This muxer supports the following options:
chunk_start_index
Index of the first chunk (defaults to 0).
header
Filename of the header where the initialization data will be written.
audio_chunk_duration
Duration of each audio chunk in milliseconds (defaults to 5000).
Example
ffmpeg -f v4l2 -i /dev/video0 \
-f alsa -i hw:0 \
-map 0:0 \
-c:v libvpx-vp9 \
-s 640x360 -keyint_min 30 -g 30 \
-f webm_chunk \
-header webm_live_video_360.hdr \
-chunk_start_index 1 \
webm_live_video_360_%d.chk \
-map 1:0 \
-c:a libvorbis \
-b:a 128k \
-f webm_chunk \
-header webm_live_audio_128.hdr \
-chunk_start_index 1 \
-audio_chunk_duration 1000 \
webm_live_audio_128_%d.chk
webm_dash_manifest
WebM DASH Manifest muxer.
This muxer implements the WebM DASH Manifest specification to generate the DASH manifest XML. It also
supports manifest generation for DASH live streams.
For more information see:
• WebM DASH Specification:
<https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification>
• ISO DASH Specification:
<http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip>
Options
This muxer supports the following options:
adaptation_sets
This option has the following syntax: "id=x,streams=a,b,c id=y,streams=d,e" where x and y are the
unique identifiers of the adaptation sets and a,b,c,d and e are the indices of the corresponding
audio and video streams. Any number of adaptation sets can be added using this option.
live
Set this to 1 to create a live stream DASH Manifest. Default: 0.
chunk_start_index
Start index of the first chunk. This will go in the startNumber attribute of the SegmentTemplate
element in the manifest. Default: 0.
chunk_duration_ms
Duration of each chunk in milliseconds. This will go in the duration attribute of the SegmentTemplate
element in the manifest. Default: 1000.
utc_timing_url
URL of the page that will return the UTC timestamp in ISO format. This will go in the value attribute
of the UTCTiming element in the manifest. Default: None.
time_shift_buffer_depth
Smallest time (in seconds) shifting buffer for which any Representation is guaranteed to be
available. This will go in the timeShiftBufferDepth attribute of the MPD element. Default: 60.
minimum_update_period
Minimum update period (in seconds) of the manifest. This will go in the minimumUpdatePeriod attribute
of the MPD element. Default: 0.
Example
ffmpeg -f webm_dash_manifest -i video1.webm \
-f webm_dash_manifest -i video2.webm \
-f webm_dash_manifest -i audio1.webm \
-f webm_dash_manifest -i audio2.webm \
-map 0 -map 1 -map 2 -map 3 \
-c copy \
-f webm_dash_manifest \
-adaptation_sets "id=0,streams=0,1 id=1,streams=2,3" \
manifest.xml
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
SEE ALSO
ffmpeg(1), ffplay(1), ffprobe(1), libavformat(3)
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 git log 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)