Provided by: ffmpeg_3.4.11-0ubuntu0.1_amd64 
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 interpreted 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
By default, ffmpeg includes only one stream of each type (video, audio, subtitle) present in the input
files and adds them to each output file. It picks the "best" of each 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. In the case where several streams of the same
type rate equally, the stream with the lowest index is chosen.
You can disable some of those defaults by using the "-vn/-an/-sn/-dn" options. For full manual control,
use the "-map" option, which disables the defaults just described.
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.
stream_type[:stream_index]
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 stream_index is given, then it matches stream
number stream_index of this type. Otherwise, it matches all streams of this type.
p:program_id[:stream_index]
If stream_index is given, then it matches the stream with number stream_index in the program with the
id program_id. Otherwise, it matches all streams in the program.
#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.
-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 [repeat+]loglevel | -v [repeat+]loglevel
Set the logging level used by the library. Adding "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. "repeat" can also be used alone. If "repeat" is used alone, and with no prior loglevel set,
the default loglevel will be used. If multiple loglevel parameters are given, using 'repeat' will not
change the 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
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 verbose".
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
-opencl_bench
This option is used to benchmark all available OpenCL devices and print the results. This option is
only available when FFmpeg has been compiled with "--enable-opencl".
When FFmpeg is configured with "--enable-opencl", the options for the global OpenCL context are set
via -opencl_options. See the "OpenCL Options" section in the ffmpeg-utils manual for the complete
list of supported options. Amongst others, these options include the ability to select a specific
platform and device to run the OpenCL code on. By default, FFmpeg will run on the first device of the
first platform. While the options for the global OpenCL context provide flexibility to the user in
selecting the OpenCL device of their choice, most users would probably want to select the fastest
OpenCL device for their system.
This option assists the selection of the most efficient configuration by identifying the appropriate
device for the user's system. The built-in benchmark is run on all the OpenCL devices and the
performance is measured for each device. The devices in the results list are sorted based on their
performance with the fastest device listed first. The user can subsequently invoke ffmpeg using the
device deemed most appropriate via -opencl_options to obtain the best performance for the OpenCL
accelerated code.
Typical usage to use the fastest OpenCL device involve the following steps.
Run the command:
ffmpeg -opencl_bench
Note down the platform ID (pidx) and device ID (didx) of the first i.e. fastest device in the list.
Select the platform and device using the command:
ffmpeg -opencl_options platform_idx=<pidx>:device_idx=<didx> ...
-opencl_options options (global)
Set OpenCL environment options. This option is only available when FFmpeg has been compiled with
"--enable-opencl".
options must be a list of key=value option pairs separated by ':'. See the ``OpenCL Options'' section
in the ffmpeg-utils manual for the list of supported options.
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.
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 (output)
Stop writing the output 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/output)
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.
-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
captions
descriptions
metadata
For example, to make the second audio stream the default stream:
ffmpeg -i in.mkv -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 INPUT -disposition:s:0 0 -disposition:s:1 default OUTPUT
-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
-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.
As an output option, this inserts the "scale" video filter to the end of the corresponding
filtergraph. Please use the "scale" filter directly to insert it at the beginning or some other
place.
The format is wxh (default - same as source).
-aspect[:stream_specifier] aspect (output,per-stream)
Set the video display aspect ratio specified by aspect.
aspect can be a floating point number string, or a string of the form num:den, where num and den are
the numerator and denominator of the aspect ratio. For example "4:3", "16:9", "1.3333", and "1.7777"
are valid argument values.
If used together with -vcodec copy, it will affect the aspect ratio stored at container level, but
not the aspect ratio stored in encoded frames, if it exists.
-vn (output)
Disable video recording.
-vcodec codec (output)
Set the video codec. This is an alias for "-codec:v".
-pass[:stream_specifier] n (output,per-stream)
Select the pass number (1 or 2). It is used to do two-pass video encoding. The statistics of the
video are recorded in the first pass into a log file (see also the option -passlogfile), and in the
second pass that log file is used to generate the video at the exact requested bitrate. On pass 1,
you may just deactivate audio and set output to null, examples for Windows and Unix:
ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
-passlogfile[:stream_specifier] prefix (output,per-stream)
Set two-pass log file name prefix to prefix, the default file name prefix is ``ffmpeg2pass''. The
complete file name will be PREFIX-N.log, where N is a number specific to the output stream
-vf filtergraph (output)
Create the filtergraph specified by filtergraph and use it to filter the stream.
This is an alias for "-filter:v", see the -filter option.
Advanced Video options
-pix_fmt[:stream_specifier] format (input/output,per-stream)
Set pixel format. Use "-pix_fmts" to show all the supported pixel formats. If the selected pixel
format can not be selected, ffmpeg will print a warning and select the best pixel format supported by
the encoder. If pix_fmt is prefixed by a "+", ffmpeg will exit with an error if the requested pixel
format can not be selected, and automatic conversions inside filtergraphs are disabled. If pix_fmt
is a single "+", ffmpeg selects the same pixel format as the input (or graph output) and automatic
conversions are disabled.
-sws_flags flags (input/output)
Set SwScaler flags.
-vdt n
Discard threshold.
-rc_override[:stream_specifier] override (output,per-stream)
Rate control override for specific intervals, formatted as "int,int,int" list separated with slashes.
Two first values are the beginning and end frame numbers, last one is quantizer to use if positive,
or quality factor if negative.
-ilme
Force interlacing support in encoder (MPEG-2 and MPEG-4 only). Use this option if your input file is
interlaced and you want to keep the interlaced format for minimum losses. The alternative is to
deinterlace the input stream with -deinterlace, but deinterlacing introduces losses.
-psnr
Calculate PSNR of compressed frames.
-vstats
Dump video coding statistics to vstats_HHMMSS.log.
-vstats_file file
Dump video coding statistics to file.
-vstats_version file
Specifies which version of the vstats format to use. Default is 2.
version = 1 :
"frame= %5d q= %2.1f PSNR= %6.2f f_size= %6d s_size= %8.0fkB time= %0.3f br= %7.1fkbits/s avg_br=
%7.1fkbits/s"
version > 1:
"out= %2d st= %2d frame= %5d q= %2.1f PSNR= %6.2f f_size= %6d s_size= %8.0fkB time= %0.3f br=
%7.1fkbits/s avg_br= %7.1fkbits/s"
-top[:stream_specifier] n (output,per-stream)
top=1/bottom=0/auto=-1 field first
-dc precision
Intra_dc_precision.
-vtag fourcc/tag (output)
Force video tag/fourcc. This is an alias for "-tag:v".
-qphist (global)
Show QP histogram
-vbsf bitstream_filter
Deprecated see -bsf
-force_key_frames[:stream_specifier] time[,time...] (output,per-stream)
-force_key_frames[:stream_specifier] expr:expr (output,per-stream)
Force key frames at the specified timestamps, more precisely at the first frames after each specified
time.
If the argument is prefixed with "expr:", the string expr is interpreted like an expression and is
evaluated for each frame. A key frame is forced in case the evaluation is non-zero.
If one of the times is ""chapters"[delta]", it is expanded into the time of the beginning of all
chapters in the file, shifted by delta, expressed as a time in seconds. This option can be useful to
ensure that a seek point is present at a chapter mark or any other designated place in the output
file.
For example, to insert a key frame at 5 minutes, plus key frames 0.1 second before the beginning of
every chapter:
-force_key_frames 0:05:00,chapters-0.1
The expression in expr can contain the following constants:
n the number of current processed frame, starting from 0
n_forced
the number of forced frames
prev_forced_n
the number of the previous forced frame, it is "NAN" when no keyframe was forced yet
prev_forced_t
the time of the previous forced frame, it is "NAN" when no keyframe was forced yet
t the time of the current processed frame
For example to force a key frame every 5 seconds, you can specify:
-force_key_frames expr:gte(t,n_forced*5)
To force a key frame 5 seconds after the time of the last forced one, starting from second 13:
-force_key_frames expr:if(isnan(prev_forced_t),gte(t,13),gte(t,prev_forced_t+5))
Note that forcing too many keyframes is very harmful for the lookahead algorithms of certain
encoders: using fixed-GOP options or similar would be more efficient.
-copyinkf[:stream_specifier] (output,per-stream)
When doing stream copy, copy also non-key frames found at the beginning.
-init_hw_device type[=name][:device[,key=value...]]
Initialise a new hardware device of type type called name, using the given device parameters. If no
name is specified it will receive a default name of the form "type%d".
The meaning of device and the following arguments depends on the device type:
cuda
device is the number of the CUDA device.
dxva2
device is the number of the Direct3D 9 display adapter.
vaapi
device is either an X11 display name or a DRM render node. If not specified, it will attempt to
open the default X11 display ($DISPLAY) and then the first DRM render node (/dev/dri/renderD128).
vdpau
device is an X11 display name. If not specified, it will attempt to open the default X11 display
($DISPLAY).
qsv device selects a value in MFX_IMPL_*. Allowed values are:
auto
sw
hw
auto_any
hw_any
hw2
hw3
hw4
If not specified, auto_any is used. (Note that it may be easier to achieve the desired result
for QSV by creating the platform-appropriate subdevice (dxva2 or vaapi) and then deriving a QSV
device from that.)
-init_hw_device type[=name]@source
Initialise a new hardware device of type type called name, deriving it from the existing device with
the name source.
-init_hw_device list
List all hardware device types supported in this build of ffmpeg.
-filter_hw_device name
Pass the hardware device called name to all filters in any filter graph. This can be used to set the
device to upload to with the "hwupload" filter, or the device to map to with the "hwmap" filter.
Other filters may also make use of this parameter when they require a hardware device. Note that
this is typically only required when the input is not already in hardware frames - when it is,
filters will derive the device they require from the context of the frames they receive as input.
This is a global setting, so all filters will receive the same device.
-hwaccel[:stream_specifier] hwaccel (input,per-stream)
Use hardware acceleration to decode the matching stream(s). The allowed values of hwaccel are:
none
Do not use any hardware acceleration (the default).
auto
Automatically select the hardware acceleration method.
vda Use Apple VDA hardware acceleration.
vdpau
Use VDPAU (Video Decode and Presentation API for Unix) hardware acceleration.
dxva2
Use DXVA2 (DirectX Video Acceleration) hardware acceleration.
vaapi
Use VAAPI (Video Acceleration API) hardware acceleration.
qsv Use the Intel QuickSync Video acceleration for video transcoding.
Unlike most other values, this option does not enable accelerated decoding (that is used
automatically whenever a qsv decoder is selected), but accelerated transcoding, without copying
the frames into the system memory.
For it to work, both the decoder and the encoder must support QSV acceleration and no filters
must be used.
This option has no effect if the selected hwaccel is not available or not supported by the chosen
decoder.
Note that most acceleration methods are intended for playback and will not be faster than software
decoding on modern CPUs. Additionally, ffmpeg will usually need to copy the decoded frames from the
GPU memory into the system memory, resulting in further performance loss. This option is thus mainly
useful for testing.
-hwaccel_device[:stream_specifier] hwaccel_device (input,per-stream)
Select a device to use for hardware acceleration.
This option only makes sense when the -hwaccel option is also specified. It can either refer to an
existing device created with -init_hw_device by name, or it can create a new device as if
-init_hw_device type:hwaccel_device were called immediately before.
-hwaccels
List all hardware acceleration methods supported in this build of ffmpeg.
Audio Options
-aframes number (output)
Set the number of audio frames to output. This is an obsolete alias for "-frames:a", which you should
use instead.
-ar[:stream_specifier] freq (input/output,per-stream)
Set the audio sampling frequency. For output streams it is set by default to the frequency of the
corresponding input stream. For input streams this option only makes sense for audio grabbing devices
and raw demuxers and is mapped to the corresponding demuxer options.
-aq q (output)
Set the audio quality (codec-specific, VBR). This is an alias for -q:a.
-ac[:stream_specifier] channels (input/output,per-stream)
Set the number of audio channels. For output streams it is set by default to the number of input
audio channels. For input streams this option only makes sense for audio grabbing devices and raw
demuxers and is mapped to the corresponding demuxer options.
-an (output)
Disable audio recording.
-acodec codec (input/output)
Set the audio codec. This is an alias for "-codec:a".
-sample_fmt[:stream_specifier] sample_fmt (output,per-stream)
Set the audio sample format. Use "-sample_fmts" to get a list of supported sample formats.
-af filtergraph (output)
Create the filtergraph specified by filtergraph and use it to filter the stream.
This is an alias for "-filter:a", see the -filter option.
Advanced Audio options
-atag fourcc/tag (output)
Force audio tag/fourcc. This is an alias for "-tag:a".
-absf bitstream_filter
Deprecated, see -bsf
-guess_layout_max channels (input,per-stream)
If some input channel layout is not known, try to guess only if it corresponds to at most the
specified number of channels. For example, 2 tells to ffmpeg to recognize 1 channel as mono and 2
channels as stereo but not 6 channels as 5.1. The default is to always try to guess. Use 0 to disable
all guessing.
Subtitle options
-scodec codec (input/output)
Set the subtitle codec. This is an alias for "-codec:s".
-sn (output)
Disable subtitle recording.
-sbsf bitstream_filter
Deprecated, see -bsf
Advanced Subtitle options
-fix_sub_duration
Fix subtitles durations. For each subtitle, wait for the next packet in the same stream and adjust
the duration of the first to avoid overlap. This is necessary with some subtitles codecs, especially
DVB subtitles, because the duration in the original packet is only a rough estimate and the end is
actually marked by an empty subtitle frame. Failing to use this option when necessary can result in
exaggerated durations or muxing failures due to non-monotonic timestamps.
Note that this option will delay the output of all data until the next subtitle packet is decoded: it
may increase memory consumption and latency a lot.
-canvas_size size
Set the size of the canvas used to render subtitles.
Advanced options
-map [-]input_file_id[:stream_specifier][?][,sync_file_id[:stream_specifier]] | [linklabel] (output)
Designate one or more input streams as a source for the output file. Each input stream is identified
by the input file index input_file_id and the input stream index input_stream_id within the input
file. Both indices start at 0. If specified, sync_file_id:stream_specifier sets which input stream is
used as a presentation sync reference.
The first "-map" option on the command line specifies the source for output stream 0, the second
"-map" option specifies the source for output stream 1, etc.
A "-" character before the stream identifier creates a "negative" mapping. It disables matching
streams from already created mappings.
A trailing "?" after the stream index will allow the map to be optional: if the map matches no
streams the map will be ignored instead of failing. Note the map will still fail if an invalid input
file index is used; such as if the map refers to a non-existent input.
An alternative [linklabel] form will map outputs from complex filter graphs (see the -filter_complex
option) to the output file. linklabel must correspond to a defined output link label in the graph.
For example, to map ALL streams from the first input file to output
ffmpeg -i INPUT -map 0 output
For example, if you have two audio streams in the first input file, these streams are identified by
"0:0" and "0:1". You can use "-map" to select which streams to place in an output file. For example:
ffmpeg -i INPUT -map 0:1 out.wav
will map the input stream in INPUT identified by "0:1" to the (single) output stream in out.wav.
For example, to select the stream with index 2 from input file a.mov (specified by the identifier
"0:2"), and stream with index 6 from input b.mov (specified by the identifier "1:6"), and copy them
to the output file out.mov:
ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
To select all video and the third audio stream from an input file:
ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT
To map all the streams except the second audio, use negative mappings
ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT
To map the video and audio streams from the first input, and using the trailing "?", ignore the audio
mapping if no audio streams exist in the first input:
ffmpeg -i INPUT -map 0:v -map 0:a? OUTPUT
To pick the English audio stream:
ffmpeg -i INPUT -map 0:m:language:eng OUTPUT
Note that using this option disables the default mappings for this output file.
-ignore_unknown
Ignore input streams with unknown type instead of failing if copying such streams is attempted.
-copy_unknown
Allow input streams with unknown type to be copied instead of failing if copying such streams is
attempted.
-map_channel [input_file_id.stream_specifier.channel_id|-1][?][:output_file_id.stream_specifier]
Map an audio channel from a given input to an output. If output_file_id.stream_specifier is not set,
the audio channel will be mapped on all the audio streams.
Using "-1" instead of input_file_id.stream_specifier.channel_id will map a muted channel.
A trailing "?" will allow the map_channel to be optional: if the map_channel matches no channel the
map_channel will be ignored instead of failing.
For example, assuming INPUT is a stereo audio file, you can switch the two audio channels with the
following command:
ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT
If you want to mute the first channel and keep the second:
ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT
The order of the "-map_channel" option specifies the order of the channels in the output stream. The
output channel layout is guessed from the number of channels mapped (mono if one "-map_channel",
stereo if two, etc.). Using "-ac" in combination of "-map_channel" makes the channel gain levels to
be updated if input and output channel layouts don't match (for instance two "-map_channel" options
and "-ac 6").
You can also extract each channel of an input to specific outputs; the following command extracts two
channels of the INPUT audio stream (file 0, stream 0) to the respective OUTPUT_CH0 and OUTPUT_CH1
outputs:
ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1
The following example splits the channels of a stereo input into two separate streams, which are put
into the same output file:
ffmpeg -i stereo.wav -map 0:0 -map 0:0 -map_channel 0.0.0:0.0 -map_channel 0.0.1:0.1 -y out.ogg
Note that currently each output stream can only contain channels from a single input stream; you
can't for example use "-map_channel" to pick multiple input audio channels contained in different
streams (from the same or different files) and merge them into a single output stream. It is
therefore not currently possible, for example, to turn two separate mono streams into a single stereo
stream. However splitting a stereo stream into two single channel mono streams is possible.
If you need this feature, a possible workaround is to use the amerge filter. For example, if you need
to merge a media (here input.mkv) with 2 mono audio streams into one single stereo channel audio
stream (and keep the video stream), you can use the following command:
ffmpeg -i input.mkv -filter_complex "[0:1] [0:2] amerge" -c:a pcm_s16le -c:v copy output.mkv
To map the first two audio channels from the first input, and using the trailing "?", ignore the
audio channel mapping if the first input is mono instead of stereo:
ffmpeg -i INPUT -map_channel 0.0.0 -map_channel 0.0.1? OUTPUT
-map_metadata[:metadata_spec_out] infile[:metadata_spec_in] (output,per-metadata)
Set metadata information of the next output file from infile. Note that those are file indices (zero-
based), not filenames. Optional metadata_spec_in/out parameters specify, which metadata to copy. A
metadata specifier can have the following forms:
g global metadata, i.e. metadata that applies to the whole file
s[:stream_spec]
per-stream metadata. stream_spec is a stream specifier as described in the Stream specifiers
chapter. In an input metadata specifier, the first matching stream is copied from. In an output
metadata specifier, all matching streams are copied to.
c:chapter_index
per-chapter metadata. chapter_index is the zero-based chapter index.
p:program_index
per-program metadata. program_index is the zero-based program index.
If metadata specifier is omitted, it defaults to global.
By default, global metadata is copied from the first input file, per-stream and per-chapter metadata
is copied along with streams/chapters. These default mappings are disabled by creating any mapping of
the relevant type. A negative file index can be used to create a dummy mapping that just disables
automatic copying.
For example to copy metadata from the first stream of the input file to global metadata of the output
file:
ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3
To do the reverse, i.e. copy global metadata to all audio streams:
ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv
Note that simple 0 would work as well in this example, since global metadata is assumed by default.
-map_chapters input_file_index (output)
Copy chapters from input file with index input_file_index to the next output file. If no chapter
mapping is specified, then chapters are copied from the first input file with at least one chapter.
Use a negative file index to disable any chapter copying.
-benchmark (global)
Show benchmarking information at the end of an encode. Shows CPU time used and maximum memory
consumption. Maximum memory consumption is not supported on all systems, it will usually display as
0 if not supported.
-benchmark_all (global)
Show benchmarking information during the encode. Shows CPU time used in various steps (audio/video
encode/decode).
-timelimit duration (global)
Exit after ffmpeg has been running for duration seconds.
-dump (global)
Dump each input packet to stderr.
-hex (global)
When dumping packets, also dump the payload.
-re (input)
Read input at native frame rate. Mainly used to simulate a grab device, or live input stream (e.g.
when reading from a file). Should not be used with actual grab devices or live input streams (where
it can cause packet loss). By default ffmpeg attempts to read the input(s) as fast as possible.
This option will slow down the reading of the input(s) to the native frame rate of the input(s). It
is useful for real-time output (e.g. live streaming).
-loop_input
Loop over the input stream. Currently it works only for image streams. This option is used for
automatic FFserver testing. This option is deprecated, use -loop 1.
-loop_output number_of_times
Repeatedly loop output for formats that support looping such as animated GIF (0 will loop the output
infinitely). This option is deprecated, use -loop.
-vsync parameter
Video sync method. For compatibility reasons old values can be specified as numbers. Newly added
values will have to be specified as strings always.
0, passthrough
Each frame is passed with its timestamp from the demuxer to the muxer.
1, cfr
Frames will be duplicated and dropped to achieve exactly the requested constant frame rate.
2, vfr
Frames are passed through with their timestamp or dropped so as to prevent 2 frames from having
the same timestamp.
drop
As passthrough but destroys all timestamps, making the muxer generate fresh timestamps based on
frame-rate.
-1, auto
Chooses between 1 and 2 depending on muxer capabilities. This is the default method.
Note that the timestamps may be further modified by the muxer, after this. For example, in the case
that the format option avoid_negative_ts is enabled.
With -map you can select from which stream the timestamps should be taken. You can leave either video
or audio unchanged and sync the remaining stream(s) to the unchanged one.
-frame_drop_threshold parameter
Frame drop threshold, which specifies how much behind video frames can be before they are dropped. In
frame rate units, so 1.0 is one frame. The default is -1.1. One possible usecase is to avoid
framedrops in case of noisy timestamps or to increase frame drop precision in case of exact
timestamps.
-async samples_per_second
Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps, the parameter is
the maximum samples per second by which the audio is changed. -async 1 is a special case where only
the start of the audio stream is corrected without any later correction.
Note that the timestamps may be further modified by the muxer, after this. For example, in the case
that the format option avoid_negative_ts is enabled.
This option has been deprecated. Use the "aresample" audio filter instead.
-copyts
Do not process input timestamps, but keep their values without trying to sanitize them. In
particular, do not remove the initial start time offset value.
Note that, depending on the vsync option or on specific muxer processing (e.g. in case the format
option avoid_negative_ts is enabled) the output timestamps may mismatch with the input timestamps
even when this option is selected.
-start_at_zero
When used with copyts, shift input timestamps so they start at zero.
This means that using e.g. "-ss 50" will make output timestamps start at 50 seconds, regardless of
what timestamp the input file started at.
-copytb mode
Specify how to set the encoder timebase when stream copying. mode is an integer numeric value, and
can assume one of the following values:
1 Use the demuxer timebase.
The time base is copied to the output encoder from the corresponding input demuxer. This is
sometimes required to avoid non monotonically increasing timestamps when copying video streams
with variable frame rate.
0 Use the decoder timebase.
The time base is copied to the output encoder from the corresponding input decoder.
-1 Try to make the choice automatically, in order to generate a sane output.
Default value is -1.
-enc_time_base[:stream_specifier] timebase (output,per-stream)
Set the encoder timebase. timebase is a floating point number, and can assume one of the following
values:
0 Assign a default value according to the media type.
For video - use 1/framerate, for audio - use 1/samplerate.
-1 Use the input stream timebase when possible.
If an input stream is not available, the default timebase will be used.
>0 Use the provided number as the timebase.
This field can be provided as a ratio of two integers (e.g. 1:24, 1:48000) or as a floating point
number (e.g. 0.04166, 2.0833e-5)
Default value is 0.
-shortest (output)
Finish encoding when the shortest input stream ends.
-dts_delta_threshold
Timestamp discontinuity delta threshold.
-muxdelay seconds (input)
Set the maximum demux-decode delay.
-muxpreload seconds (input)
Set the initial demux-decode delay.
-streamid output-stream-index:new-value (output)
Assign a new stream-id value to an output stream. This option should be specified prior to the output
filename to which it applies. For the situation where multiple output files exist, a streamid may be
reassigned to a different value.
For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for an output mpegts file:
ffmpeg -i inurl -streamid 0:33 -streamid 1:36 out.ts
-bsf[:stream_specifier] bitstream_filters (output,per-stream)
Set bitstream filters for matching streams. bitstream_filters is a comma-separated list of bitstream
filters. Use the "-bsfs" option to get the list of bitstream filters.
ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264
ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt
-tag[:stream_specifier] codec_tag (input/output,per-stream)
Force a tag/fourcc for matching streams.
-timecode hh:mm:ssSEPff
Specify Timecode for writing. SEP is ':' for non drop timecode and ';' (or '.') for drop.
ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg
-filter_complex filtergraph (global)
Define a complex filtergraph, i.e. one with arbitrary number of inputs and/or outputs. For simple
graphs -- those with one input and one output of the same type -- see the -filter options.
filtergraph is a description of the filtergraph, as described in the ``Filtergraph syntax'' section
of the ffmpeg-filters manual.
Input link labels must refer to input streams using the "[file_index:stream_specifier]" syntax (i.e.
the same as -map uses). If stream_specifier matches multiple streams, the first one will be used. An
unlabeled input will be connected to the first unused input stream of the matching type.
Output link labels are referred to with -map. Unlabeled outputs are added to the first output file.
Note that with this option it is possible to use only lavfi sources without normal input files.
For example, to overlay an image over video
ffmpeg -i video.mkv -i image.png -filter_complex '[0:v][1:v]overlay[out]' -map
'[out]' out.mkv
Here "[0:v]" refers to the first video stream in the first input file, which is linked to the first
(main) input of the overlay filter. Similarly the first video stream in the second input is linked to
the second (overlay) input of overlay.
Assuming there is only one video stream in each input file, we can omit input labels, so the above is
equivalent to
ffmpeg -i video.mkv -i image.png -filter_complex 'overlay[out]' -map
'[out]' out.mkv
Furthermore we can omit the output label and the single output from the filter graph will be added to
the output file automatically, so we can simply write
ffmpeg -i video.mkv -i image.png -filter_complex 'overlay' out.mkv
To generate 5 seconds of pure red video using lavfi "color" source:
ffmpeg -filter_complex 'color=c=red' -t 5 out.mkv
-filter_complex_threads nb_threads (global)
Defines how many threads are used to process a filter_complex graph. Similar to filter_threads but
used for "-filter_complex" graphs only. The default is the number of available CPUs.
-lavfi filtergraph (global)
Define a complex filtergraph, i.e. one with arbitrary number of inputs and/or outputs. Equivalent to
-filter_complex.
-filter_complex_script filename (global)
This option is similar to -filter_complex, the only difference is that its argument is the name of
the file from which a complex filtergraph description is to be read.
-accurate_seek (input)
This option enables or disables accurate seeking in input files with the -ss option. It is enabled by
default, so seeking is accurate when transcoding. Use -noaccurate_seek to disable it, which may be
useful e.g. when copying some streams and transcoding the others.
-seek_timestamp (input)
This option enables or disables seeking by timestamp in input files with the -ss option. It is
disabled by default. If enabled, the argument to the -ss option is considered an actual timestamp,
and is not offset by the start time of the file. This matters only for files which do not start from
timestamp 0, such as transport streams.
-thread_queue_size size (input)
This option sets the maximum number of queued packets when reading from the file or device. With low
latency / high rate live streams, packets may be discarded if they are not read in a timely manner;
raising this value can avoid it.
-override_ffserver (global)
Overrides the input specifications from ffserver. Using this option you can map any input stream to
ffserver and control many aspects of the encoding from ffmpeg. Without this option ffmpeg will
transmit to ffserver what is requested by ffserver.
The option is intended for cases where features are needed that cannot be specified to ffserver but
can be to ffmpeg.
-sdp_file file (global)
Print sdp information for an output stream to file. This allows dumping sdp information when at
least one output isn't an rtp stream. (Requires at least one of the output formats to be rtp).
-discard (input)
Allows discarding specific streams or frames of streams at the demuxer. Not all demuxers support
this.
none
Discard no frame.
default
Default, which discards no frames.
noref
Discard all non-reference frames.
bidir
Discard all bidirectional frames.
nokey
Discard all frames excepts keyframes.
all Discard all frames.
-abort_on flags (global)
Stop and abort on various conditions. The following flags are available:
empty_output
No packets were passed to the muxer, the output is empty.
-xerror (global)
Stop and exit on error
-max_muxing_queue_size packets (output,per-stream)
When transcoding audio and/or video streams, ffmpeg will not begin writing into the output until it
has one packet for each such stream. While waiting for that to happen, packets for other streams are
buffered. This option sets the size of this buffer, in packets, for the matching output stream.
The default value of this option should be high enough for most uses, so only touch this option if
you are sure that you need it.
As a special exception, you can use a bitmap subtitle stream as input: it will be converted into a video
with the same size as the largest video in the file, or 720x576 if no video is present. Note that this is
an experimental and temporary solution. It will be removed once libavfilter has proper support for
subtitles.
For example, to hardcode subtitles on top of a DVB-T recording stored in MPEG-TS format, delaying the
subtitles by 1 second:
ffmpeg -i input.ts -filter_complex \
'[#0x2ef] setpts=PTS+1/TB [sub] ; [#0x2d0] [sub] overlay' \
-sn -map '#0x2dc' output.mkv
(0x2d0, 0x2dc and 0x2ef are the MPEG-TS PIDs of respectively the video, audio and subtitles streams; 0:0,
0:3 and 0:7 would have worked too)
Preset files
A preset file contains a sequence of option=value pairs, one for each line, specifying a sequence of
options which would be awkward to specify on the command line. Lines starting with the hash ('#')
character are ignored and are used to provide comments. Check the presets directory in the FFmpeg source
tree for examples.
There are two types of preset files: ffpreset and avpreset files.
ffpreset files
ffpreset files are specified with the "vpre", "apre", "spre", and "fpre" options. The "fpre" option takes
the filename of the preset instead of a preset name as input and can be used for any kind of codec. For
the "vpre", "apre", and "spre" options, the options specified in a preset file are applied to the
currently selected codec of the same type as the preset option.
The argument passed to the "vpre", "apre", and "spre" preset options identifies the preset file to use
according to the following rules:
First ffmpeg searches for a file named arg.ffpreset in the directories $FFMPEG_DATADIR (if set), and
$HOME/.ffmpeg, and in the datadir defined at configuration time (usually PREFIX/share/ffmpeg) or in a
ffpresets folder along the executable on win32, in that order. For example, if the argument is
"libvpx-1080p", it will search for the file libvpx-1080p.ffpreset.
If no such file is found, then ffmpeg will search for a file named codec_name-arg.ffpreset in the above-
mentioned directories, where codec_name is the name of the codec to which the preset file options will be
applied. For example, if you select the video codec with "-vcodec libvpx" and use "-vpre 1080p", then it
will search for the file libvpx-1080p.ffpreset.
avpreset files
avpreset files are specified with the "pre" option. They work similar to ffpreset files, but they only
allow encoder- specific options. Therefore, an option=value pair specifying an encoder cannot be used.
When the "pre" option is specified, ffmpeg will look for files with the suffix .avpreset in the
directories $AVCONV_DATADIR (if set), and $HOME/.avconv, and in the datadir defined at configuration time
(usually PREFIX/share/ffmpeg), in that order.
First ffmpeg searches for a file named codec_name-arg.avpreset in the above-mentioned directories, where
codec_name is the name of the codec to which the preset file options will be applied. For example, if you
select the video codec with "-vcodec libvpx" and use "-pre 1080p", then it will search for the file
libvpx-1080p.avpreset.
If no such file is found, then ffmpeg will search for a file named arg.avpreset in the same directories.
EXAMPLES
Video and Audio grabbing
If you specify the input format and device then ffmpeg can grab video and audio directly.
ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
Or with an ALSA audio source (mono input, card id 1) instead of OSS:
ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg
Note that you must activate the right video source and channel before launching ffmpeg with any TV viewer
such as <http://linux.bytesex.org/xawtv/> by Gerd Knorr. You also have to set the audio recording levels
correctly with a standard mixer.
X11 grabbing
Grab the X11 display with ffmpeg via
ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0 /tmp/out.mpg
0.0 is display.screen number of your X11 server, same as the DISPLAY environment variable.
ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0+10,20 /tmp/out.mpg
0.0 is display.screen number of your X11 server, same as the DISPLAY environment variable. 10 is the
x-offset and 20 the y-offset for the grabbing.
Video and Audio file format conversion
Any supported file format and protocol can serve as input to ffmpeg:
Examples:
• You can use YUV files as input:
ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
It will use the files:
/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
The Y files use twice the resolution of the U and V files. They are raw files, without header. They
can be generated by all decent video decoders. You must specify the size of the image with the -s
option if ffmpeg cannot guess it.
• You can input from a raw YUV420P file:
ffmpeg -i /tmp/test.yuv /tmp/out.avi
test.yuv is a file containing raw YUV planar data. Each frame is composed of the Y plane followed by
the U and V planes at half vertical and horizontal resolution.
• You can output to a raw YUV420P file:
ffmpeg -i mydivx.avi hugefile.yuv
• You can set several input files and output files:
ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
Converts the audio file a.wav and the raw YUV video file a.yuv to MPEG file a.mpg.
• You can also do audio and video conversions at the same time:
ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
Converts a.wav to MPEG audio at 22050 Hz sample rate.
• You can encode to several formats at the same time and define a mapping from input stream to output
streams:
ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2
Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map file:index' specifies which
input stream is used for each output stream, in the order of the definition of output streams.
• You can transcode decrypted VOBs:
ffmpeg -i snatch_1.vob -f avi -c:v mpeg4 -b:v 800k -g 300 -bf 2 -c:a libmp3lame -b:a 128k snatch.avi
This is a typical DVD ripping example; the input is a VOB file, the output an AVI file with MPEG-4
video and MP3 audio. Note that in this command we use B-frames so the MPEG-4 stream is DivX5
compatible, and GOP size is 300 which means one intra frame every 10 seconds for 29.97fps input
video. Furthermore, the audio stream is MP3-encoded so you need to enable LAME support by passing
"--enable-libmp3lame" to configure. The mapping is particularly useful for DVD transcoding to get
the desired audio language.
NOTE: To see the supported input formats, use "ffmpeg -demuxers".
• You can extract images from a video, or create a video from many images:
For extracting images from a video:
ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
This will extract one video frame per second from the video and will output them in files named
foo-001.jpeg, foo-002.jpeg, etc. Images will be rescaled to fit the new WxH values.
If you want to extract just a limited number of frames, you can use the above command in combination
with the "-frames:v" or "-t" option, or in combination with -ss to start extracting from a certain
point in time.
For creating a video from many images:
ffmpeg -f image2 -framerate 12 -i foo-%03d.jpeg -s WxH foo.avi
The syntax "foo-%03d.jpeg" specifies to use a decimal number composed of three digits padded with
zeroes to express the sequence number. It is the same syntax supported by the C printf function, but
only formats accepting a normal integer are suitable.
When importing an image sequence, -i also supports expanding shell-like wildcard patterns (globbing)
internally, by selecting the image2-specific "-pattern_type glob" option.
For example, for creating a video from filenames matching the glob pattern "foo-*.jpeg":
ffmpeg -f image2 -pattern_type glob -framerate 12 -i 'foo-*.jpeg' -s WxH foo.avi
• You can put many streams of the same type in the output:
ffmpeg -i test1.avi -i test2.avi -map 1:1 -map 1:0 -map 0:1 -map 0:0 -c copy -y test12.nut
The resulting output file test12.nut will contain the first four streams from the input files in
reverse order.
• To force CBR video output:
ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
• The four options lmin, lmax, mblmin and mblmax use 'lambda' units, but you may use the QP2LAMBDA
constant to easily convert from 'q' units:
ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
SEE ALSO
ffmpeg-all(1), ffplay(1), ffprobe(1), ffserver(1), ffmpeg-utils(1), ffmpeg-scaler(1),
ffmpeg-resampler(1), ffmpeg-codecs(1), ffmpeg-bitstream-filters(1), ffmpeg-formats(1), ffmpeg-devices(1),
ffmpeg-protocols(1), ffmpeg-filters(1)
AUTHORS
The FFmpeg developers.
For details about the authorship, see the Git history of the project (git://source.ffmpeg.org/ffmpeg),
e.g. by typing the command git log in the FFmpeg source directory, or browsing the online repository at
<http://source.ffmpeg.org>.
Maintainers for the specific components are listed in the file MAINTAINERS in the source code tree.
FFMPEG(1)