ffmpeg - ffmpeg video converter
ffmpeg [
global_options] {[
input_file_options] -i
input_url} ... {[
output_file_options]
output_url} ...
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.
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.
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 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.
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.
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.
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.
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.
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.
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 named
filter_name. Use the -filters option to get a list of all
filters.
-
bsf=bitstream_filter_name
- Print detailed information about the bitstream filter named
bitstream_filter_name. Use the -bsfs option to get a list of
all bitstream filters.
-
protocol=protocol_name
- Print detailed information about the protocol named
protocol_name. Use the -protocols option to get a list of
all protocols.
- -version
- Show version.
- -buildconf
- Show the build configuration, one option per line.
- -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.
- -dispositions
- Show stream dispositions.
- -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 can be forced
setting the environment variable
AV_LOG_FORCE_COLOR.
- -report
- Dump full command line and log 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
- PowerPC
- Specific Processors
- pentium2
- pentium3
- pentium4
- k6
- k62
- athlon
- athlonxp
- k8
-
-cpucount count
(global)
- Override detection of CPU count. This option is intended
for testing. Do not use it unless you know what you're doing.
ffmpeg -cpucount 2
-
-max_alloc bytes
- Set the maximum size limit for allocating a block on the
heap by ffmpeg's family of malloc functions. Exercise extreme
caution when using this option. Don't use if you do not understand the
full consequence of doing so. Default is INT_MAX.
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.
-
-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.
-
-recast_media (global)
- Allow forcing a decoder of a different media type than the
one detected or designated by the demuxer. Useful for decoding media data
muxed as data streams.
-
-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.
-
-isync input_index
(input)
- Assign an input as a sync source.
This will take the difference between the start times of the target and
reference inputs and offset the timestamps of the target file by that
difference. The source timestamps of the two inputs should derive from the
same clock source for expected results. If "copyts" is set then
"start_at_zero" must also be set. If either of the inputs has no
starting timestamp then no sync adjustment is made.
Acceptable values are those that refer to a valid ffmpeg input index. If the
sync reference is the target index itself or -1, then no adjustment
is made to target timestamps. A sync reference may not itself be synced to
any other input.
Default value is -1.
-
-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.
By default, the disposition is copied from the input stream, unless the
output stream this option applies to is fed by a complex filtergraph - in
that case the disposition is unset by default.
value is a sequence of items separated by '+' or '-'. The first item
may also be prefixed with '+' or '-', in which case this option modifies
the default value. Otherwise (the first item is not prefixed) this options
overrides the default value. A '+' prefix adds the given disposition, '-'
removes it. It is also possible to clear the disposition by setting it to
0.
If no "-disposition" options were specified for an output file,
ffmpeg will automatically set the 'default' disposition on the first
stream of each type, when there are multiple streams of this type in the
output file and no stream of that type is already marked as default.
The "-dispositions" option lists the known dispositions.
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
The parameters set for each target are as follows.
VCD
<pal>:
-f vcd -muxrate 1411200 -muxpreload 0.44 -packetsize 2324
-s 352x288 -r 25
-codec:v mpeg1video -g 15 -b:v 1150k -maxrate:v 1150k -minrate:v 1150k -bufsize:v 327680
-ar 44100 -ac 2
-codec:a mp2 -b:a 224k
<ntsc>:
-f vcd -muxrate 1411200 -muxpreload 0.44 -packetsize 2324
-s 352x240 -r 30000/1001
-codec:v mpeg1video -g 18 -b:v 1150k -maxrate:v 1150k -minrate:v 1150k -bufsize:v 327680
-ar 44100 -ac 2
-codec:a mp2 -b:a 224k
<film>:
-f vcd -muxrate 1411200 -muxpreload 0.44 -packetsize 2324
-s 352x240 -r 24000/1001
-codec:v mpeg1video -g 18 -b:v 1150k -maxrate:v 1150k -minrate:v 1150k -bufsize:v 327680
-ar 44100 -ac 2
-codec:a mp2 -b:a 224k
SVCD
<pal>:
-f svcd -packetsize 2324
-s 480x576 -pix_fmt yuv420p -r 25
-codec:v mpeg2video -g 15 -b:v 2040k -maxrate:v 2516k -minrate:v 0 -bufsize:v 1835008 -scan_offset 1
-ar 44100
-codec:a mp2 -b:a 224k
<ntsc>:
-f svcd -packetsize 2324
-s 480x480 -pix_fmt yuv420p -r 30000/1001
-codec:v mpeg2video -g 18 -b:v 2040k -maxrate:v 2516k -minrate:v 0 -bufsize:v 1835008 -scan_offset 1
-ar 44100
-codec:a mp2 -b:a 224k
<film>:
-f svcd -packetsize 2324
-s 480x480 -pix_fmt yuv420p -r 24000/1001
-codec:v mpeg2video -g 18 -b:v 2040k -maxrate:v 2516k -minrate:v 0 -bufsize:v 1835008 -scan_offset 1
-ar 44100
-codec:a mp2 -b:a 224k
DVD
<pal>:
-f dvd -muxrate 10080k -packetsize 2048
-s 720x576 -pix_fmt yuv420p -r 25
-codec:v mpeg2video -g 15 -b:v 6000k -maxrate:v 9000k -minrate:v 0 -bufsize:v 1835008
-ar 48000
-codec:a ac3 -b:a 448k
<ntsc>:
-f dvd -muxrate 10080k -packetsize 2048
-s 720x480 -pix_fmt yuv420p -r 30000/1001
-codec:v mpeg2video -g 18 -b:v 6000k -maxrate:v 9000k -minrate:v 0 -bufsize:v 1835008
-ar 48000
-codec:a ac3 -b:a 448k
<film>:
-f dvd -muxrate 10080k -packetsize 2048
-s 720x480 -pix_fmt yuv420p -r 24000/1001
-codec:v mpeg2video -g 18 -b:v 6000k -maxrate:v 9000k -minrate:v 0 -bufsize:v 1835008
-ar 48000
-codec:a ac3 -b:a 448k
DV
<pal>:
-f dv
-s 720x576 -pix_fmt yuv420p -r 25
-ar 48000 -ac 2
<ntsc>:
-f dv
-s 720x480 -pix_fmt yuv411p -r 30000/1001
-ar 48000 -ac 2
<film>:
-f dv
-s 720x480 -pix_fmt yuv411p -r 24000/1001
-ar 48000 -ac 2
The "dv50" target is identical to the "dv" target except
that the pixel format set is "yuv422p" for all three standards.
Any user-set value for a parameter above will override the target preset
value. In that case, the output may not comply with the target
standard.
-
-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.
-
-reinit_filter[:stream_specifier]
integer (input,per-stream)
- This boolean option determines if the filtergraph(s) to
which this stream is fed gets reinitialized when input frame parameters
change mid-stream. This option is enabled by default as most video and all
audio filters cannot handle deviation in input frame properties. Upon
reinitialization, existing filter state is lost, like e.g. the frame count
"n" reference available in some filters. Any frames buffered at
time of reinitialization are lost. The properties where a change triggers
reinitialization are, for video, frame resolution or pixel format; for
audio, sample format, sample rate, channel count or channel layout.
-
-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".
-
-stats_period time
(global)
- Set period at which encoding progress/statistics are
updated. Default is 0.5 seconds.
-
-progress url
(global)
- Send program-friendly progress information to url.
Progress information is written periodically 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".
The update period is set using "-stats_period".
- -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.
-
-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.
-
-fpsmax[:stream_specifier] fps
(output,per-stream)
- Set maximum frame rate (Hz value, fraction or
abbreviation).
Clamps output frame rate when output framerate is auto-set and is higher
than this value. Useful in batch processing or when input framerate is
wrongly detected as very high. It cannot be set together with
"-r". It is ignored during streamcopy.
-
-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 (input/output)
- As an input option, blocks all video 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 video recording i.e. automatic selection or
mapping of any video stream. For full manual control see the
"-map" option.
-
-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.
- -autorotate
- Automatically rotate the video according to file metadata.
Enabled by default, use -noautorotate to disable it.
- -autoscale
- Automatically scale the video according to the resolution
of first frame. Enabled by default, use -noautoscale to disable it.
When autoscale is disabled, all output frames of filter graph might not be
in the same resolution and may be inadequate for some encoder/muxer.
Therefore, it is not recommended to disable it unless you really know what
you are doing. Disable autoscale at your own risk.
-
-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.
-
-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 by use of a filter such as "yadif"
or "bwdif", 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[:stream_specifier]
source ( output,per-stream)
-
-force_key_frames[:stream_specifier]
source_no_drop ( output,per-stream)
-
force_key_frames can take arguments of the following
form:
-
time[,time...]
- If the argument consists of timestamps, ffmpeg will round
the specified times to the nearest output timestamp as per the encoder
time base and force a keyframe at the first frame having timestamp equal
or greater than the computed timestamp. Note that if the encoder time base
is too coarse, then the keyframes may be forced on frames with timestamps
lower than the specified time. The default encoder time base is the
inverse of the output framerate but may be set otherwise via
"-enc_time_base".
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
-
expr:expr
- 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.
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))
- source
- If the argument is "source", ffmpeg will force a
key frame if the current frame being encoded is marked as a key frame in
its source.
- source_no_drop
- If the argument is "source_no_drop", ffmpeg will
force a key frame if the current frame being encoded is marked as a key
frame in its source. In cases where this particular source frame has to be
dropped, enforce the next available frame to become a key frame
instead.
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.
The following options are recognized:
- primary_ctx
- If set to 1, uses the primary device context instead of
creating a new one.
Examples:
- -init_hw_device cuda:1
- Choose the second device on the system.
- -init_hw_device cuda:0,primary_ctx=1
- Choose the first device and use the primary device
context.
- dxva2
-
device is the number of the Direct3D 9 display
adapter.
- d3d11va
-
device is the number of the Direct3D 11 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
d3d11va or
vaapi) and then deriving
a QSV device from that.)
Alternatively,
child_device_type helps to choose platform-appropriate
subdevice type. On Windows
d3d11va is used as default subdevice type.
Examples:
- -init_hw_device
qsv:hw,child_device_type=d3d11va
- Choose the GPU subdevice with type d3d11va and
create QSV device with MFX_IMPL_HARDWARE.
- -init_hw_device qsv:hw,child_device_type=dxva2
- Choose the GPU subdevice with type dxva2 and create
QSV device with MFX_IMPL_HARDWARE.
- opencl
-
device selects the platform and device as
platform_index.device_index.
The set of devices can also be filtered using the key-value pairs to find
only devices matching particular platform or device strings.
The strings usable as filters are:
- platform_profile
- platform_version
- platform_name
- platform_vendor
- platform_extensions
- device_name
- device_vendor
- driver_version
- device_version
- device_profile
- device_extensions
- device_type
The indices and filters must together uniquely select a device.
Examples:
- -init_hw_device opencl:0.1
- Choose the second device on the first platform.
- -init_hw_device opencl:,device_name=Foo9000
- Choose the device with a name containing the string
Foo9000.
- -init_hw_device
opencl:1,device_type=gpu,device_extensions=cl_khr_fp16
- Choose the GPU device on the second platform supporting the
cl_khr_fp16 extension.
- vulkan
- If device is an integer, it selects the device by
its index in a system-dependent list of devices. If device is any
other string, it selects the first device with a name containing that
string as a substring.
The following options are recognized:
- debug
- If set to 1, enables the validation layer, if
installed.
- linear_images
- If set to 1, images allocated by the hwcontext will be
linear and locally mappable.
- instance_extensions
- A plus separated list of additional instance extensions to
enable.
- device_extensions
- A plus separated list of additional device extensions to
enable.
Examples:
- -init_hw_device vulkan:1
- Choose the second device on the system.
- -init_hw_device vulkan:RADV
- Choose the first device with a name containing the string
RADV.
- -init_hw_device
vulkan:0,instance_extensions=VK_KHR_wayland_surface+VK_KHR_xcb_surface
- Choose the first device and enable the Wayland and XCB
instance extensions.
-
-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.
- vdpau
- Use VDPAU (Video Decode and Presentation API for Unix)
hardware acceleration.
- dxva2
- Use DXVA2 (DirectX Video Acceleration) hardware
acceleration.
- d3d11va
- Use D3D11VA (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 components enabled in this
build of ffmpeg. Actual runtime availability depends on the hardware and
its suitable driver being installed.
-
-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 (input/output)
- As an input option, blocks all audio 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 audio recording i.e. automatic selection or
mapping of any audio stream. For full manual control see the
"-map" option.
-
-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.
-
-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.
-
-scodec codec
(input/output)
- Set the subtitle codec. This is an alias for
"-codec:s".
-
-sn (input/output)
- As an input option, blocks all subtitle 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 subtitle recording i.e. automatic selection or
mapping of any subtitle stream. For full manual control see the
"-map" option.
-
-sbsf bitstream_filter
- Deprecated, see -bsf
- -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.
-
-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 real, system and user 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
real, system and user time used in various steps (audio/video
encode/decode).
-
-timelimit duration
(global)
- Exit after ffmpeg has been running for duration
seconds in CPU user time.
-
-dump (global)
- Dump each input packet to stderr.
-
-hex (global)
- When dumping packets, also dump the payload.
-
-readrate speed
(input)
- Limit input read speed.
Its value is a floating-point positive number which represents the maximum
duration of media, in seconds, that should be ingested in one second of
wallclock time. Default value is zero and represents no imposed limitation
on speed of ingestion. Value 1 represents real-time speed and is
equivalent to "-re".
Mainly used to simulate a capture device or live input stream (e.g. when
reading from a file). Should not be used with a low value when input is an
actual capture device or live stream as it may cause packet loss.
It is useful for when flow speed of output packets is important, such as
live streaming.
-
-re (input)
- Read input at native frame rate. This is equivalent to
setting "-readrate 1".
-
-vsync parameter
(global)
-
-fps_mode[:stream_specifier]
parameter (output,per-stream)
- Set video sync method / framerate mode. vsync is applied to
all output video streams but can be overridden for a stream by setting
fps_mode. vsync is deprecated and will be removed in the future.
For compatibility reasons some of the values for vsync can be specified as
numbers (shown in parentheses in the following table).
- passthrough (0)
- Each frame is passed with its timestamp from the demuxer to
the muxer.
- cfr (1)
- Frames will be duplicated and dropped to achieve exactly
the requested constant frame rate.
- vfr (2)
- 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.
- auto (-1)
- Chooses between cfr and vfr 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.
-
-adrift_threshold time
- Set the minimum difference between timestamps and audio
data (in seconds) to trigger adding/dropping samples to make it match the
timestamps. This option effectively is a threshold to select between hard
(add/drop) and soft (squeeze/stretch) compensation. "-async"
must be set to a positive value.
-
-apad parameters
(output,per-stream )
- Pad the output audio stream(s). This is the same as
applying "-af apad". Argument is a string of filter parameters
composed the same as with the "apad" filter.
"-shortest" must be set for this output for the option to take
effect.
- -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.
-
-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)
-
-bitexact (input/output)
- Enable bitexact mode for (de)muxer and (de/en)coder
-
-shortest (output)
- Finish encoding when the shortest output stream ends.
- -dts_delta_threshold
- Timestamp discontinuity delta threshold.
-
-dts_error_threshold seconds
- Timestamp error delta threshold. This threshold use to
discard crazy/damaged timestamps and the default is 30 hours which is
arbitrarily picked and quite conservative.
-
-muxdelay seconds
(output)
- Set the maximum demux-decode delay.
-
-muxpreload seconds
(output)
- 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:ss SEPff
- 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
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)
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;
setting this value can force ffmpeg to use a separate input thread and
read packets as soon as they arrive. By default ffmpeg only does this if
multiple inputs are specified.
-
-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 from streams.
Any input stream can be fully discarded, using value "all"
whereas selective discarding of frames from a stream occurs at the demuxer
and is not supported by all demuxers.
- 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.
- empty_output_stream
- No packets were passed to the muxer in some of the output
streams.
-
-max_error_rate (global)
- Set fraction of decoding frame failures across all inputs
which when crossed ffmpeg will return exit code 69. Crossing this
threshold does not terminate processing. Range is a floating-point number
between 0 to 1. Default is 2/3.
-
-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.
-
-muxing_queue_data_threshold bytes
(output,per-stream)
- This is a minimum threshold until which the muxing queue
size is not taken into account. Defaults to 50 megabytes per stream, and
is based on the overall size of packets passed to the muxer.
-
-auto_conversion_filters (global)
- Enable automatically inserting format conversion filters in
all filter graphs, including those defined by -vf, -af,
-filter_complex and -lavfi. If filter format negotiation
requires a conversion, the initialization of the filters will fail.
Conversions can still be performed by inserting the relevant conversion
filter (scale, aresample) in the graph. On by default, to explicitly
disable it you need to specify
"-noauto_conversion_filters".
-
-bits_per_raw_sample[:stream_specifier]
value (output,per-stream)
- Declare the number of bits per raw sample in the given
output stream to be value. Note that this option sets the
information provided to the encoder/muxer, it does not change the stream
to conform to this value. Setting values that do not match the stream
properties may result in encoding failures or invalid output 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.
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.
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.
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
ffmpeg-all(1),
ffplay(1),
ffprobe(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)
The FFmpeg developers.
For details about the authorship, see the Git history of the project
(
https://git.ffmpeg.org/ffmpeg), e.g. by typing the command
git log in
the FFmpeg source directory, or browsing the online repository at <
https://git.ffmpeg.org/ffmpeg>.
Maintainers for the specific components are listed in the file
MAINTAINERS in the source code tree.