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ffmpeg.txt
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FFMPEG(1) FFMPEG(1)
NAME
ffmpeg - ffmpeg video converter
SYNOPSIS
ffmpeg [global_options] {[input_file_options] -i input_url} ...
{[output_file_options] output_url} ...
DESCRIPTION
ffmpeg is a very fast video and audio converter that can also
grab from a live audio/video source. It can also convert between
arbitrary sample rates and resize video on the fly with a high
quality polyphase filter.
ffmpeg reads from an arbitrary number of input "files" (which
can be regular files, pipes, network streams, grabbing devices,
etc.), specified by the "-i" option, and writes to an arbitrary
number of output "files", which are specified by a plain output
url. Anything found on the command line which cannot be inter-
preted as an option is considered to be an output url.
Each input or output url can, in principle, contain any number of
streams of different types (video/audio/subtitle/attachment/data).
The allowed number and/or types of streams may be limited by the
container format. Selecting which streams from which inputs will
go into which output is either done automatically or with the
"-map" option (see the Stream selection chapter).
To refer to input files in options, you must use their indices
(0-based). E.g. the first input file is 0, the second is 1, etc.
Similarly, streams within a file are referred to by their indices.
E.g. "2:3" refers to the fourth stream in the third input file.
Also see the Stream specifiers chapter.
As a general rule, options are applied to the next specified file.
Therefore, order is important, and you can have the same option on
the command line multiple times. Each occurrence is then applied
to the next input or output file. Exceptions from this rule are
the global options (e.g. verbosity level), which should be specified
first.
Do not mix input and output files -- first specify all input files,
then all output files. Also do not mix options which belong to
different files. All options apply ONLY to the next input or output
file and are reset between files.
• To set the video bitrate of the output file to 64 kbit/s:
ffmpeg -i input.avi -b:v 64k -bufsize 64k output.avi
• To force the frame rate of the output file to 24 fps:
ffmpeg -i input.avi -r 24 output.avi
• To force the frame rate of the input file (valid for raw formats only) to 1 fps and the frame
rate of the output file to 24 fps:
ffmpeg -r 1 -i input.m2v -r 24 output.avi
The format option may be needed for raw input files.
DETAILED DESCRIPTION
The transcoding process in ffmpeg for each output can be described by the following diagram:
_______ ______________
| | | |
| input | demuxer | encoded data | decoder
| file | ---------> | packets | -----+
|_______| |______________| |
v
_________
| |
| decoded |
| frames |
|_________|
________ ______________ |
| | | | |
| output | <-------- | encoded data | <----+
| file | muxer | packets | encoder
|________| |______________|
ffmpeg calls the libavformat library (containing demuxers) to read input files and get packets
containing encoded data from them. When there are multiple input files, ffmpeg tries to keep them
synchronized by tracking lowest timestamp on any active input stream.
Encoded packets are then passed to the decoder (unless streamcopy is selected for the stream, see
further for a description). The decoder produces uncompressed frames (raw video/PCM audio/...)
which can be processed further by filtering (see next section). After filtering, the frames are
passed to the encoder, which encodes them and outputs encoded packets. Finally those are passed to
the muxer, which writes the encoded packets to the output file.
Filtering
Before encoding, ffmpeg can process raw audio and video frames using filters from the libavfilter
library. Several chained filters form a filter graph. ffmpeg distinguishes between two types of
filtergraphs: simple and complex.
Simple filtergraphs
Simple filtergraphs are those that have exactly one input and output, both of the same type. In
the above diagram they can be represented by simply inserting an additional step between decoding
and encoding:
_________ ______________
| | | |
| decoded | | encoded data |
| frames |\ _ | packets |
|_________| \ /||______________|
\ __________ /
simple _\|| | / encoder
filtergraph | filtered |/
| frames |
|__________|
Simple filtergraphs are configured with the per-stream -filter option (with -vf and -af aliases
for video and audio respectively). A simple filtergraph for video can look for example like this:
_______ _____________ _______ ________
| | | | | | | |
| input | ---> | deinterlace | ---> | scale | ---> | output |
|_______| |_____________| |_______| |________|
Note that some filters change frame properties but not frame contents. E.g. the "fps" filter in
the example above changes number of frames, but does not touch the frame contents. Another example
is the "setpts" filter, which only sets timestamps and otherwise passes the frames unchanged.
Complex filtergraphs
Complex filtergraphs are those which cannot be described as simply a linear processing chain
applied to one stream. This is the case, for example, when the graph has more than one input
and/or output, or when output stream type is different from input. They can be represented with
the following diagram:
_________
| |
| input 0 |\ __________
|_________| \ | |
\ _________ /| output 0 |
\ | | / |__________|
_________ \| complex | /
| | | |/
| input 1 |---->| filter |\
|_________| | | \ __________
/| graph | \ | |
/ | | \| output 1 |
_________ / |_________| |__________|
| | /
| input 2 |/
|_________|
Complex filtergraphs are configured with the -filter_complex option. Note that this option is
global, since a complex filtergraph, by its nature, cannot be unambiguously associated with a
single stream or file.
The -lavfi option is equivalent to -filter_complex.
A trivial example of a complex filtergraph is the "overlay" filter, which has two video inputs and
one video output, containing one video overlaid on top of the other. Its audio counterpart is the
"amix" filter.
Stream copy
Stream copy is a mode selected by supplying the "copy" parameter to the -codec option. It makes
ffmpeg omit the decoding and encoding step for the specified stream, so it does only demuxing and
muxing. It is useful for changing the container format or modifying container-level metadata. The
diagram above will, in this case, simplify to this:
_______ ______________ ________
| | | | | |
| input | demuxer | encoded data | muxer | output |
| file | ---------> | packets | -------> | file |
|_______| |______________| |________|
Since there is no decoding or encoding, it is very fast and there is no quality loss. However, it
might not work in some cases because of many factors. Applying filters is obviously also
impossible, since filters work on uncompressed data.
STREAM SELECTION
ffmpeg provides the "-map" option for manual control of stream selection in each output file.
Users can skip "-map" and let ffmpeg perform automatic stream selection as described below. The
"-vn / -an / -sn / -dn" options can be used to skip inclusion of video, audio, subtitle and data
streams respectively, whether manually mapped or automatically selected, except for those streams
which are outputs of complex filtergraphs.
Description
The sub-sections that follow describe the various rules that are involved in stream selection.
The examples that follow next show how these rules are applied in practice.
While every effort is made to accurately reflect the behavior of the program, FFmpeg is under
continuous development and the code may have changed since the time of this writing.
Automatic stream selection
In the absence of any map options for a particular output file, ffmpeg inspects the output format
to check which type of streams can be included in it, viz. video, audio and/or subtitles. For each
acceptable stream type, ffmpeg will pick one stream, when available, from among all the inputs.
It will select that stream based upon the following criteria:
• for video, it is the stream with the highest resolution,
• for audio, it is the stream with the most channels,
• for subtitles, it is the first subtitle stream found but there's a caveat. The output
format's default subtitle encoder can be either text-based or image-based, and only a subtitle
stream of the same type will be chosen.
In the case where several streams of the same type rate equally, the stream with the lowest index
is chosen.
Data or attachment streams are not automatically selected and can only be included using "-map".
Manual stream selection
When "-map" is used, only user-mapped streams are included in that output file, with one possible
exception for filtergraph outputs described below.
Complex filtergraphs
If there are any complex filtergraph output streams with unlabeled pads, they will be added to the
first output file. This will lead to a fatal error if the stream type is not supported by the
output format. In the absence of the map option, the inclusion of these streams leads to the
automatic stream selection of their types being skipped. If map options are present, these
filtergraph streams are included in addition to the mapped streams.
Complex filtergraph output streams with labeled pads must be mapped once and exactly once.
Stream handling
Stream handling is independent of stream selection, with an exception for subtitles described
below. Stream handling is set via the "-codec" option addressed to streams within a specific
output file. In particular, codec options are applied by ffmpeg after the stream selection process
and thus do not influence the latter. If no "-codec" option is specified for a stream type, ffmpeg
will select the default encoder registered by the output file muxer.
An exception exists for subtitles. If a subtitle encoder is specified for an output file, the
first subtitle stream found of any type, text or image, will be included. ffmpeg does not validate
if the specified encoder can convert the selected stream or if the converted stream is acceptable
within the output format. This applies generally as well: when the user sets an encoder manually,
the stream selection process cannot check if the encoded stream can be muxed into the output file.
If it cannot, ffmpeg will abort and all output files will fail to be processed.
Examples
The following examples illustrate the behavior, quirks and limitations of ffmpeg's stream
selection methods.
They assume the following three input files.
input file 'A.avi'
stream 0: video 640x360
stream 1: audio 2 channels
input file 'B.mp4'
stream 0: video 1920x1080
stream 1: audio 2 channels
stream 2: subtitles (text)
stream 3: audio 5.1 channels
stream 4: subtitles (text)
input file 'C.mkv'
stream 0: video 1280x720
stream 1: audio 2 channels
stream 2: subtitles (image)
Example: automatic stream selection
ffmpeg -i A.avi -i B.mp4 out1.mkv out2.wav -map 1:a -c:a copy out3.mov
There are three output files specified, and for the first two, no "-map" options are set, so
ffmpeg will select streams for these two files automatically.
out1.mkv is a Matroska container file and accepts video, audio and subtitle streams, so ffmpeg
will try to select one of each type.For video, it will select "stream 0" from B.mp4, which has the
highest resolution among all the input video streams.For audio, it will select "stream 3" from
B.mp4, since it has the greatest number of channels.For subtitles, it will select "stream 2" from
B.mp4, which is the first subtitle stream from among A.avi and B.mp4.
out2.wav accepts only audio streams, so only "stream 3" from B.mp4 is selected.
For out3.mov, since a "-map" option is set, no automatic stream selection will occur. The "-map
1:a" option will select all audio streams from the second input B.mp4. No other streams will be
included in this output file.
For the first two outputs, all included streams will be transcoded. The encoders chosen will be
the default ones registered by each output format, which may not match the codec of the selected
input streams.
For the third output, codec option for audio streams has been set to "copy", so no decoding-
filtering-encoding operations will occur, or can occur. Packets of selected streams shall be
conveyed from the input file and muxed within the output file.
Example: automatic subtitles selection
ffmpeg -i C.mkv out1.mkv -c:s dvdsub -an out2.mkv
Although out1.mkv is a Matroska container file which accepts subtitle streams, only a video and
audio stream shall be selected. The subtitle stream of C.mkv is image-based and the default
subtitle encoder of the Matroska muxer is text-based, so a transcode operation for the subtitles
is expected to fail and hence the stream isn't selected. However, in out2.mkv, a subtitle encoder
is specified in the command and so, the subtitle stream is selected, in addition to the video
stream. The presence of "-an" disables audio stream selection for out2.mkv.
Example: unlabeled filtergraph outputs
ffmpeg -i A.avi -i C.mkv -i B.mp4 -filter_complex "overlay" out1.mp4 out2.srt
A filtergraph is setup here using the "-filter_complex" option and consists of a single video
filter. The "overlay" filter requires exactly two video inputs, but none are specified, so the
first two available video streams are used, those of A.avi and C.mkv. The output pad of the filter
has no label and so is sent to the first output file out1.mp4. Due to this, automatic selection of
the video stream is skipped, which would have selected the stream in B.mp4. The audio stream with
most channels viz. "stream 3" in B.mp4, is chosen automatically. No subtitle stream is chosen
however, since the MP4 format has no default subtitle encoder registered, and the user hasn't
specified a subtitle encoder.
The 2nd output file, out2.srt, only accepts text-based subtitle streams. So, even though the first
subtitle stream available belongs to C.mkv, it is image-based and hence skipped. The selected
stream, "stream 2" in B.mp4, is the first text-based subtitle stream.
Example: labeled filtergraph outputs
ffmpeg -i A.avi -i B.mp4 -i C.mkv -filter_complex "[1:v]hue=s=0[outv];overlay;aresample" \
-map '[outv]' -an out1.mp4 \
out2.mkv \
-map '[outv]' -map 1:a:0 out3.mkv
The above command will fail, as the output pad labelled "[outv]" has been mapped twice. None of
the output files shall be processed.
ffmpeg -i A.avi -i B.mp4 -i C.mkv -filter_complex "[1:v]hue=s=0[outv];overlay;aresample" \
-an out1.mp4 \
out2.mkv \
-map 1:a:0 out3.mkv
This command above will also fail as the hue filter output has a label, "[outv]", and hasn't been
mapped anywhere.
The command should be modified as follows,
ffmpeg -i A.avi -i B.mp4 -i C.mkv -filter_complex "[1:v]hue=s=0,split=2[outv1][outv2];overlay;aresample" \
-map '[outv1]' -an out1.mp4 \
out2.mkv \
-map '[outv2]' -map 1:a:0 out3.mkv
The video stream from B.mp4 is sent to the hue filter, whose output is cloned once using the split
filter, and both outputs labelled. Then a copy each is mapped to the first and third output files.
The overlay filter, requiring two video inputs, uses the first two unused video streams. Those are
the streams from A.avi and C.mkv. The overlay output isn't labelled, so it is sent to the first
output file out1.mp4, regardless of the presence of the "-map" option.
The aresample filter is sent the first unused audio stream, that of A.avi. Since this filter
output is also unlabelled, it too is mapped to the first output file. The presence of "-an" only
suppresses automatic or manual stream selection of audio streams, not outputs sent from
filtergraphs. Both these mapped streams shall be ordered before the mapped stream in out1.mp4.
The video, audio and subtitle streams mapped to "out2.mkv" are entirely determined by automatic
stream selection.
out3.mkv consists of the cloned video output from the hue filter and the first audio stream from
B.mp4.
OPTIONS
All the numerical options, if not specified otherwise, accept a string representing a number as
input, which may be followed by one of the SI unit prefixes, for example: 'K', 'M', or 'G'.
If 'i' is appended to the SI unit prefix, the complete prefix will be interpreted as a unit prefix
for binary multiples, which are based on powers of 1024 instead of powers of 1000. Appending 'B'
to the SI unit prefix multiplies the value by 8. This allows using, for example: 'KB', 'MiB', 'G'
and 'B' as number suffixes.
Options which do not take arguments are boolean options, and set the corresponding value to true.
They can be set to false by prefixing the option name with "no". For example using "-nofoo" will
set the boolean option with name "foo" to false.
Stream specifiers
Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers are used to
precisely specify which stream(s) a given option belongs to.
A stream specifier is a string generally appended to the option name and separated from it by a
colon. E.g. "-codec:a:1 ac3" contains the "a:1" stream specifier, which matches the second audio
stream. Therefore, it would select the ac3 codec for the second audio stream.
A stream specifier can match several streams, so that the option is applied to all of them. E.g.
the stream specifier in "-b:a 128k" matches all audio streams.
An empty stream specifier matches all streams. For example, "-codec copy" or "-codec: copy" would
copy all the streams without reencoding.
Possible forms of stream specifiers are:
stream_index
Matches the stream with this index. E.g. "-threads:1 4" would set the thread count for the
second stream to 4. If stream_index is used as an additional stream specifier (see below),
then it selects stream number stream_index from the matching streams. Stream numbering is
based on the order of the streams as detected by libavformat except when a program ID is also
specified. In this case it is based on the ordering of the streams in the program.
stream_type[:additional_stream_specifier]
stream_type is one of following: 'v' or 'V' for video, 'a' for audio, 's' for subtitle, 'd'
for data, and 't' for attachments. 'v' matches all video streams, 'V' only matches video
streams which are not attached pictures, video thumbnails or cover arts. If
additional_stream_specifier is used, then it matches streams which both have this type and
match the additional_stream_specifier. Otherwise, it matches all streams of the specified
type.
p:program_id[:additional_stream_specifier]
Matches streams which are in the program with the id program_id. If
additional_stream_specifier is used, then it matches streams which both are part of the
program and match the additional_stream_specifier.
#stream_id or i:stream_id
Match the stream by stream id (e.g. PID in MPEG-TS container).
m:key[:value]
Matches streams with the metadata tag key having the specified value. If value is not given,
matches streams that contain the given tag with any value.
u Matches streams with usable configuration, the codec must be defined and the essential
information such as video dimension or audio sample rate must be present.
Note that in ffmpeg, matching by metadata will only work properly for input files.
Generic options
These options are shared amongst the ff* tools.
-L Show license.
-h, -?, -help, --help [arg]
Show help. An optional parameter may be specified to print help about a specific item. If no
argument is specified, only basic (non advanced) tool options are shown.
Possible values of arg are:
long
Print advanced tool options in addition to the basic tool options.
full
Print complete list of options, including shared and private options for encoders,
decoders, demuxers, muxers, filters, etc.
decoder=decoder_name
Print detailed information about the decoder named decoder_name. Use the -decoders option
to get a list of all decoders.
encoder=encoder_name
Print detailed information about the encoder named encoder_name. Use the -encoders option
to get a list of all encoders.
demuxer=demuxer_name
Print detailed information about the demuxer named demuxer_name. Use the -formats option
to get a list of all demuxers and muxers.
muxer=muxer_name
Print detailed information about the muxer named muxer_name. Use the -formats option to
get a list of all muxers and demuxers.
filter=filter_name
Print detailed information about the filter name filter_name. Use the -filters option to
get a list of all filters.
bsf=bitstream_filter_name
Print detailed information about the bitstream filter name bitstream_filter_name. Use the
-bsfs option to get a list of all bitstream filters.
-version
Show version.
-formats
Show available formats (including devices).
-demuxers
Show available demuxers.
-muxers
Show available muxers.
-devices
Show available devices.
-codecs
Show all codecs known to libavcodec.
Note that the term 'codec' is used throughout this documentation as a shortcut for what is
more correctly called a media bitstream format.
-decoders
Show available decoders.
-encoders
Show all available encoders.
-bsfs
Show available bitstream filters.
-protocols
Show available protocols.
-filters
Show available libavfilter filters.
-pix_fmts
Show available pixel formats.
-sample_fmts
Show available sample formats.
-layouts
Show channel names and standard channel layouts.
-colors
Show recognized color names.
-sources device[,opt1=val1[,opt2=val2]...]
Show autodetected sources of the input device. Some devices may provide system-dependent
source names that cannot be autodetected. The returned list cannot be assumed to be always
complete.
ffmpeg -sources pulse,server=192.168.0.4
-sinks device[,opt1=val1[,opt2=val2]...]
Show autodetected sinks of the output device. Some devices may provide system-dependent sink
names that cannot be autodetected. The returned list cannot be assumed to be always complete.
ffmpeg -sinks pulse,server=192.168.0.4
-loglevel [flags+]loglevel | -v [flags+]loglevel
Set logging level and flags used by the library.
The optional flags prefix can consist of the following values:
repeat
Indicates that repeated log output should not be compressed to the first line and the
"Last message repeated n times" line will be omitted.
level
Indicates that log output should add a "[level]" prefix to each message line. This can be
used as an alternative to log coloring, e.g. when dumping the log to file.
Flags can also be used alone by adding a '+'/'-' prefix to set/reset a single flag without
affecting other flags or changing loglevel. When setting both flags and loglevel, a '+'
separator is expected between the last flags value and before loglevel.
loglevel is a string or a number containing one of the following values:
quiet, -8
Show nothing at all; be silent.
panic, 0
Only show fatal errors which could lead the process to crash, such as an assertion
failure. This is not currently used for anything.
fatal, 8
Only show fatal errors. These are errors after which the process absolutely cannot
continue.
error, 16
Show all errors, including ones which can be recovered from.
warning, 24
Show all warnings and errors. Any message related to possibly incorrect or unexpected
events will be shown.
info, 32
Show informative messages during processing. This is in addition to warnings and errors.
This is the default value.
verbose, 40
Same as "info", except more verbose.
debug, 48
Show everything, including debugging information.
trace, 56
For example to enable repeated log output, add the "level" prefix, and set loglevel to
"verbose":
ffmpeg -loglevel repeat+level+verbose -i input output
Another example that enables repeated log output without affecting current state of "level"
prefix flag or loglevel:
ffmpeg [...] -loglevel +repeat
By default the program logs to stderr. If coloring is supported by the terminal, colors are
used to mark errors and warnings. Log coloring can be disabled setting the environment
variable AV_LOG_FORCE_NOCOLOR or NO_COLOR, or can be forced setting the environment variable
AV_LOG_FORCE_COLOR. The use of the environment variable NO_COLOR is deprecated and will be
dropped in a future FFmpeg version.
-report
Dump full command line and console output to a file named "program-YYYYMMDD-HHMMSS.log" in the
current directory. This file can be useful for bug reports. It also implies "-loglevel
debug".
Setting the environment variable FFREPORT to any value has the same effect. If the value is a
':'-separated key=value sequence, these options will affect the report; option values must be
escaped if they contain special characters or the options delimiter ':' (see the ``Quoting and
escaping'' section in the ffmpeg-utils manual).
The following options are recognized:
file
set the file name to use for the report; %p is expanded to the name of the program, %t is
expanded to a timestamp, "%%" is expanded to a plain "%"
level
set the log verbosity level using a numerical value (see "-loglevel").
For example, to output a report to a file named ffreport.log using a log level of 32 (alias
for log level "info"):
FFREPORT=file=ffreport.log:level=32 ffmpeg -i input output
Errors in parsing the environment variable are not fatal, and will not appear in the report.
-hide_banner
Suppress printing banner.
All FFmpeg tools will normally show a copyright notice, build options and library versions.
This option can be used to suppress printing this information.
-cpuflags flags (global)
Allows setting and clearing cpu flags. This option is intended for testing. Do not use it
unless you know what you're doing.
ffmpeg -cpuflags -sse+mmx ...
ffmpeg -cpuflags mmx ...
ffmpeg -cpuflags 0 ...
Possible flags for this option are:
x86
mmx
mmxext
sse
sse2
sse2slow
sse3
sse3slow
ssse3
atom
sse4.1
sse4.2
avx
avx2
xop
fma3
fma4
3dnow
3dnowext
bmi1
bmi2
cmov
ARM
armv5te
armv6
armv6t2
vfp
vfpv3
neon
setend
AArch64
armv8
vfp
neon
PowerPC
altivec
Specific Processors
pentium2
pentium3
pentium4
k6
k62
athlon
athlonxp
k8
AVOptions
These options are provided directly by the libavformat, libavdevice and libavcodec libraries. To
see the list of available AVOptions, use the -help option. They are separated into two categories:
generic
These options can be set for any container, codec or device. Generic options are listed under
AVFormatContext options for containers/devices and under AVCodecContext options for codecs.
private
These options are specific to the given container, device or codec. Private options are listed
under their corresponding containers/devices/codecs.
For example to write an ID3v2.3 header instead of a default ID3v2.4 to an MP3 file, use the
id3v2_version private option of the MP3 muxer:
ffmpeg -i input.flac -id3v2_version 3 out.mp3
All codec AVOptions are per-stream, and thus a stream specifier should be attached to them:
ffmpeg -i multichannel.mxf -map 0:v:0 -map 0:a:0 -map 0:a:0 -c:a:0 ac3 -b:a:0 640k -ac:a:1 2 -c:a:1 aac -b:2 128k out.mp4
In the above example, a multichannel audio stream is mapped twice for output. The first instance
is encoded with codec ac3 and bitrate 640k. The second instance is downmixed to 2 channels and
encoded with codec aac. A bitrate of 128k is specified for it using absolute index of the output
stream.
Note: the -nooption syntax cannot be used for boolean AVOptions, use -option 0/-option 1.
Note: the old undocumented way of specifying per-stream AVOptions by prepending v/a/s to the
options name is now obsolete and will be removed soon.
Main options
-f fmt (input/output)
Force input or output file format. The format is normally auto detected for input files and
guessed from the file extension for output files, so this option is not needed in most cases.
-i url (input)
input file url
-y (global)
Overwrite output files without asking.
-n (global)
Do not overwrite output files, and exit immediately if a specified output file already exists.
-stream_loop number (input)
Set number of times input stream shall be looped. Loop 0 means no loop, loop -1 means infinite
loop.
-c[:stream_specifier] codec (input/output,per-stream)
-codec[:stream_specifier] codec (input/output,per-stream)
Select an encoder (when used before an output file) or a decoder (when used before an input
file) for one or more streams. codec is the name of a decoder/encoder or a special value
"copy" (output only) to indicate that the stream is not to be re-encoded.
For example
ffmpeg -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT
encodes all video streams with libx264 and copies all audio streams.
For each stream, the last matching "c" option is applied, so
ffmpeg -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT
will copy all the streams except the second video, which will be encoded with libx264, and the
138th audio, which will be encoded with libvorbis.
-t duration (input/output)
When used as an input option (before "-i"), limit the duration of data read from the input
file.
When used as an output option (before an output url), stop writing the output after its
duration reaches duration.
duration must be a time duration specification, see the Time duration section in the
ffmpeg-utils(1) manual.
-to and -t are mutually exclusive and -t has priority.
-to position (input/output)
Stop writing the output or reading the input at position. position must be a time duration
specification, see the Time duration section in the ffmpeg-utils(1) manual.
-to and -t are mutually exclusive and -t has priority.
-fs limit_size (output)
Set the file size limit, expressed in bytes. No further chunk of bytes is written after the
limit is exceeded. The size of the output file is slightly more than the requested file size.
-ss position (input/output)
When used as an input option (before "-i"), seeks in this input file to position. Note that in
most formats it is not possible to seek exactly, so ffmpeg will seek to the closest seek point
before position. When transcoding and -accurate_seek is enabled (the default), this extra
segment between the seek point and position will be decoded and discarded. When doing stream
copy or when -noaccurate_seek is used, it will be preserved.
When used as an output option (before an output url), decodes but discards input until the
timestamps reach position.
position must be a time duration specification, see the Time duration section in the
ffmpeg-utils(1) manual.
-sseof position (input)
Like the "-ss" option but relative to the "end of file". That is negative values are earlier
in the file, 0 is at EOF.
-itsoffset offset (input)
Set the input time offset.
offset must be a time duration specification, see the Time duration section in the
ffmpeg-utils(1) manual.
The offset is added to the timestamps of the input files. Specifying a positive offset means
that the corresponding streams are delayed by the time duration specified in offset.
-itsscale scale (input,per-stream)
Rescale input timestamps. scale should be a floating point number.
-timestamp date (output)
Set the recording timestamp in the container.
date must be a date specification, see the Date section in the ffmpeg-utils(1) manual.
-metadata[:metadata_specifier] key=value (output,per-metadata)
Set a metadata key/value pair.
An optional metadata_specifier may be given to set metadata on streams, chapters or programs.
See "-map_metadata" documentation for details.
This option overrides metadata set with "-map_metadata". It is also possible to delete
metadata by using an empty value.
For example, for setting the title in the output file:
ffmpeg -i in.avi -metadata title="my title" out.flv
To set the language of the first audio stream:
ffmpeg -i INPUT -metadata:s:a:0 language=eng OUTPUT
-disposition[:stream_specifier] value (output,per-stream)
Sets the disposition for a stream.
This option overrides the disposition copied from the input stream. It is also possible to
delete the disposition by setting it to 0.
The following dispositions are recognized:
default
dub
original
comment
lyrics
karaoke
forced
hearing_impaired
visual_impaired
clean_effects
attached_pic
captions
descriptions
dependent
metadata
For example, to make the second audio stream the default stream:
ffmpeg -i in.mkv -c copy -disposition:a:1 default out.mkv
To make the second subtitle stream the default stream and remove the default disposition from
the first subtitle stream:
ffmpeg -i in.mkv -c copy -disposition:s:0 0 -disposition:s:1 default out.mkv
To add an embedded cover/thumbnail:
ffmpeg -i in.mp4 -i IMAGE -map 0 -map 1 -c copy -c:v:1 png -disposition:v:1 attached_pic out.mp4
Not all muxers support embedded thumbnails, and those who do, only support a few formats, like
JPEG or PNG.
-program [title=title:][program_num=program_num:]st=stream[:st=stream...] (output)
Creates a program with the specified title, program_num and adds the specified stream(s) to
it.
-target type (output)
Specify target file type ("vcd", "svcd", "dvd", "dv", "dv50"). type may be prefixed with
"pal-", "ntsc-" or "film-" to use the corresponding standard. All the format options (bitrate,
codecs, buffer sizes) are then set automatically. You can just type:
ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
Nevertheless you can specify additional options as long as you know they do not conflict with
the standard, as in:
ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
-dn (input/output)
As an input option, blocks all data streams of a file from being filtered or being
automatically selected or mapped for any output. See "-discard" option to disable streams
individually.
As an output option, disables data recording i.e. automatic selection or mapping of any data
stream. For full manual control see the "-map" option.
-dframes number (output)
Set the number of data frames to output. This is an obsolete alias for "-frames:d", which you
should use instead.
-frames[:stream_specifier] framecount (output,per-stream)
Stop writing to the stream after framecount frames.
-q[:stream_specifier] q (output,per-stream)
-qscale[:stream_specifier] q (output,per-stream)
Use fixed quality scale (VBR). The meaning of q/qscale is codec-dependent. If qscale is used
without a stream_specifier then it applies only to the video stream, this is to maintain
compatibility with previous behavior and as specifying the same codec specific value to 2
different codecs that is audio and video generally is not what is intended when no
stream_specifier is used.
-filter[:stream_specifier] filtergraph (output,per-stream)
Create the filtergraph specified by filtergraph and use it to filter the stream.
filtergraph is a description of the filtergraph to apply to the stream, and must have a single
input and a single output of the same type of the stream. In the filtergraph, the input is
associated to the label "in", and the output to the label "out". See the ffmpeg-filters manual
for more information about the filtergraph syntax.
See the -filter_complex option if you want to create filtergraphs with multiple inputs and/or
outputs.
-filter_script[:stream_specifier] filename (output,per-stream)
This option is similar to -filter, the only difference is that its argument is the name of the
file from which a filtergraph description is to be read.
-filter_threads nb_threads (global)
Defines how many threads are used to process a filter pipeline. Each pipeline will produce a
thread pool with this many threads available for parallel processing. The default is the
number of available CPUs.
-pre[:stream_specifier] preset_name (output,per-stream)
Specify the preset for matching stream(s).
-stats (global)
Print encoding progress/statistics. It is on by default, to explicitly disable it you need to
specify "-nostats".
-progress url (global)
Send program-friendly progress information to url.
Progress information is written approximately every second and at the end of the encoding
process. It is made of "key=value" lines. key consists of only alphanumeric characters. The
last key of a sequence of progress information is always "progress".
-stdin
Enable interaction on standard input. On by default unless standard input is used as an input.
To explicitly disable interaction you need to specify "-nostdin".
Disabling interaction on standard input is useful, for example, if ffmpeg is in the background
process group. Roughly the same result can be achieved with "ffmpeg ... < /dev/null" but it
requires a shell.
-debug_ts (global)
Print timestamp information. It is off by default. This option is mostly useful for testing
and debugging purposes, and the output format may change from one version to another, so it
should not be employed by portable scripts.
See also the option "-fdebug ts".
-attach filename (output)
Add an attachment to the output file. This is supported by a few formats like Matroska for
e.g. fonts used in rendering subtitles. Attachments are implemented as a specific type of
stream, so this option will add a new stream to the file. It is then possible to use per-
stream options on this stream in the usual way. Attachment streams created with this option
will be created after all the other streams (i.e. those created with "-map" or automatic
mappings).
Note that for Matroska you also have to set the mimetype metadata tag:
ffmpeg -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv
(assuming that the attachment stream will be third in the output file).
-dump_attachment[:stream_specifier] filename (input,per-stream)
Extract the matching attachment stream into a file named filename. If filename is empty, then
the value of the "filename" metadata tag will be used.
E.g. to extract the first attachment to a file named 'out.ttf':
ffmpeg -dump_attachment:t:0 out.ttf -i INPUT
To extract all attachments to files determined by the "filename" tag:
ffmpeg -dump_attachment:t "" -i INPUT
Technical note -- attachments are implemented as codec extradata, so this option can actually
be used to extract extradata from any stream, not just attachments.
-noautorotate
Disable automatically rotating video based on file metadata.
Video Options
-vframes number (output)
Set the number of video frames to output. This is an obsolete alias for "-frames:v", which you
should use instead.
-r[:stream_specifier] fps (input/output,per-stream)
Set frame rate (Hz value, fraction or abbreviation).
As an input option, ignore any timestamps stored in the file and instead generate timestamps
assuming constant frame rate fps. This is not the same as the -framerate option used for some
input formats like image2 or v4l2 (it used to be the same in older versions of FFmpeg). If in
doubt use -framerate instead of the input option -r.
As an output option, duplicate or drop input frames to achieve constant output frame rate fps.
-s[:stream_specifier] size (input/output,per-stream)
Set frame size.
As an input option, this is a shortcut for the video_size private option, recognized by some
demuxers for which the frame size is either not stored in the file or is configurable -- e.g.
raw video or video grabbers.