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FFMPEG-FORMATS(1) FFMPEG-FORMATS(1)
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
o 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'
o 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).
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
o 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
o 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
o 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.
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
o 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
o 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.
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
o 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
o Use ffmpeg to compute the CRC of the input, and store it in the
file out.crc:
ffmpeg -i INPUT -f crc out.crc
o Use ffmpeg to print the CRC to stdout with the command:
ffmpeg -i INPUT -f crc -
o 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:
o ISO DASH Specification:
<http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip>
o 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.
In addition, each muxed packet size must not be greater than 65535
bytes.
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,asetnsamples=3640 slow.302
The asetnsamples filter is used to reduce the number of samples of each
audio packet, with a size computed according to the formula:
65535 / (<channels> * <encoded_sample_size>) = 655535 / (6 * 3) = 3640
The encoded_sample_size = 3 factor is due to sample size of the
pcm_24daud encoder.
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
fifo
The fifo pseudo-muxer allows the separation of encoding and muxing by
using 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.
API users should be aware that callback functions (interrupt_callback,
io_open and io_close) used within its AVFormatContext must be thread-
safe.
The behavior of the fifo muxer if the queue fills up or if the output
fails is selectable,
o output can be transparently restarted with configurable delay
between retries based on real time or time of the processed stream.
o encoding can be blocked during temporary failure, or continue
transparently dropping packets in case fifo queue fills up.
fifo_format
Specify the format name. Useful if it cannot be guessed from the
output name suffix.
queue_size
Specify size of the queue (number of packets). Default value is 60.
format_opts
Specify format options for the underlying muxer. Muxer options can
be specified as a list of key=value pairs separated by ':'.
drop_pkts_on_overflow bool
If set to 1 (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 0
(false), so in such cases the encoder will be blocked until the
muxer processes some of the packets and none of them is lost.
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 0 (false).
max_recovery_attempts
Sets maximum number of successive unsuccessful recovery attempts
after which the output fails permanently. By default this option is
set to 0 (unlimited).
recovery_wait_time duration
Waiting time before the next recovery attempt after previous
unsuccessful recovery attempt. Default value is 5 seconds.
recovery_wait_streamtime bool
If set to 0 (false), the real time is used when waiting for the
recovery attempt (i.e. the recovery will be attempted after at
least recovery_wait_time seconds). If set to 1 (true), the time of
the processed stream is taken into account instead (i.e. the
recovery will be attempted after at least recovery_wait_time
seconds of the stream is omitted). By default, this option is set
to 0 (false).
recover_any_error bool
If set to 1 (true), recovery will be attempted regardless of type
of the error causing the failure. By default this option is set to
0 (false) and in case of certain (usually permanent) errors the
recovery is not attempted even when attempt_recovery is set to 1.
restart_with_keyframe bool
Specify whether to wait for the keyframe after recovering from
queue overflow or failure. This option is set to 0 (false) by
default.
timeshift duration
Buffer the specified amount of packets and delay writing the
output. Note that queue_size must be big enough to store the
packets for timeshift. At the end of the input the fifo buffer is
flushed at realtime speed.
Examples
o Stream something to 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 -map 0:v -map 0:a
-drop_pkts_on_overflow 1 -attempt_recovery 1 -recovery_wait_time 1 rtmp://example.com/live/stream_name
flv
Adobe Flash Video Format muxer.
This muxer accepts the following 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.
It accepts the following options:
loop
Set the number of times to loop the output. Use "-1" for no loop, 0
for looping indefinitely (default).
final_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.
For example, to 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"
Note 2: the GIF format has a very large time base: the delay between
two frames can therefore not be smaller than one centi second.
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.
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:
o Size cannot exceed 256 pixels in any dimension
o Only BMP and PNG images can be stored
o 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
o If a BMP image is used, it must use the BITMAPINFOHEADER DIB header
o 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:
o 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.
o 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.
o 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
o 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
o 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
o 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
o 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.
o 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
o 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
o 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
o 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/"
o 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/"
o 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"
o 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:
o WebM DASH Specification:
<https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification>
o 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)
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