FFMPEG(1)FFMPEG(1)NAME
ffmpeg - ffmpeg video converter
SYNOPSIS
ffmpeg [global_options] {[input_file_options] -i input_file} ...
{[output_file_options] output_file} ...
DESCRIPTION
ffmpeg is a very fast video and audio converter that can also grab from
a live audio/video source. It can also convert between arbitrary sample
rates and resize video on the fly with a high quality polyphase filter.
ffmpeg reads from an arbitrary number of input "files" (which can be
regular files, pipes, network streams, grabbing devices, etc.),
specified by the "-i" option, and writes to an arbitrary number of
output "files", which are specified by a plain output filename.
Anything found on the command line which cannot be interpreted as an
option is considered to be an output filename.
Each input or output file can, in principle, contain any number of
streams of different types (video/audio/subtitle/attachment/data). The
allowed number and/or types of streams may be limited by the container
format. Selecting which streams from which inputs will go into which
output is either done automatically or with the "-map" option (see the
Stream selection chapter).
To refer to input files in options, you must use their indices
(0-based). E.g. the first input file is 0, the second is 1, etc.
Similarly, streams within a file are referred to by their indices. E.g.
"2:3" refers to the fourth stream in the third input file. Also see the
Stream specifiers chapter.
As a general rule, options are applied to the next specified file.
Therefore, order is important, and you can have the same option on the
command line multiple times. Each occurrence is then applied to the
next input or output file. Exceptions from this rule are the global
options (e.g. verbosity level), which should be specified first.
Do not mix input and output files -- first specify all input files,
then all output files. Also do not mix options which belong to
different files. All options apply ONLY to the next input or output
file and are reset between files.
· To set the video bitrate of the output file to 64 kbit/s:
ffmpeg -i input.avi -b:v 64k -bufsize 64k output.avi
· To force the frame rate of the output file to 24 fps:
ffmpeg -i input.avi -r 24 output.avi
· To force the frame rate of the input file (valid for raw formats
only) to 1 fps and the frame rate of the output file to 24 fps:
ffmpeg -r 1 -i input.m2v -r 24 output.avi
The format option may be needed for raw input files.
DETAILED DESCRIPTION
The transcoding process in ffmpeg for each output can be described by
the following diagram:
_______ ______________
| | | |
| input | demuxer | encoded data | decoder
| file | ---------> | packets | -----+
|_______| |______________| |
v
_________
| |
| decoded |
| frames |
|_________|
________ ______________ |
| | | | |
| output | <-------- | encoded data | <----+
| file | muxer | packets | encoder
|________| |______________|
ffmpeg calls the libavformat library (containing demuxers) to read
input files and get packets containing encoded data from them. When
there are multiple input files, ffmpeg tries to keep them synchronized
by tracking lowest timestamp on any active input stream.
Encoded packets are then passed to the decoder (unless streamcopy is
selected for the stream, see further for a description). The decoder
produces uncompressed frames (raw video/PCM audio/...) which can be
processed further by filtering (see next section). After filtering, the
frames are passed to the encoder, which encodes them and outputs
encoded packets. Finally those are passed to the muxer, which writes
the encoded packets to the output file.
Filtering
Before encoding, ffmpeg can process raw audio and video frames using
filters from the libavfilter library. Several chained filters form a
filter graph. ffmpeg distinguishes between two types of filtergraphs:
simple and complex.
Simple filtergraphs
Simple filtergraphs are those that have exactly one input and output,
both of the same type. In the above diagram they can be represented by
simply inserting an additional step between decoding and encoding:
_________ ______________
| | | |
| decoded | | encoded data |
| frames |\ _ | packets |
|_________| \ /||______________|
\ __________ /
simple _\|| | / encoder
filtergraph | filtered |/
| frames |
|__________|
Simple filtergraphs are configured with the per-stream -filter option
(with -vf and -af aliases for video and audio respectively). A simple
filtergraph for video can look for example like this:
_______ _____________ _______ ________
| | | | | | | |
| input | ---> | deinterlace | ---> | scale | ---> | output |
|_______| |_____________| |_______| |________|
Note that some filters change frame properties but not frame contents.
E.g. the "fps" filter in the example above changes number of frames,
but does not touch the frame contents. Another example is the "setpts"
filter, which only sets timestamps and otherwise passes the frames
unchanged.
Complex filtergraphs
Complex filtergraphs are those which cannot be described as simply a
linear processing chain applied to one stream. This is the case, for
example, when the graph has more than one input and/or output, or when
output stream type is different from input. They can be represented
with the following diagram:
_________
| |
| input 0 |\ __________
|_________| \ | |
\ _________ /| output 0 |
\ | | / |__________|
_________ \| complex | /
| | | |/
| input 1 |---->| filter |\
|_________| | | \ __________
/| graph | \ | |
/ | | \| output 1 |
_________ / |_________| |__________|
| | /
| input 2 |/
|_________|
Complex filtergraphs are configured with the -filter_complex option.
Note that this option is global, since a complex filtergraph, by its
nature, cannot be unambiguously associated with a single stream or
file.
The -lavfi option is equivalent to -filter_complex.
A trivial example of a complex filtergraph is the "overlay" filter,
which has two video inputs and one video output, containing one video
overlaid on top of the other. Its audio counterpart is the "amix"
filter.
Stream copy
Stream copy is a mode selected by supplying the "copy" parameter to the
-codec option. It makes ffmpeg omit the decoding and encoding step for
the specified stream, so it does only demuxing and muxing. It is useful
for changing the container format or modifying container-level
metadata. The diagram above will, in this case, simplify to this:
_______ ______________ ________
| | | | | |
| input | demuxer | encoded data | muxer | output |
| file | ---------> | packets | -------> | file |
|_______| |______________| |________|
Since there is no decoding or encoding, it is very fast and there is no
quality loss. However, it might not work in some cases because of many
factors. Applying filters is obviously also impossible, since filters
work on uncompressed data.
STREAM SELECTION
By default, ffmpeg includes only one stream of each type (video, audio,
subtitle) present in the input files and adds them to each output file.
It picks the "best" of each based upon the following criteria: for
video, it is the stream with the highest resolution, for audio, it is
the stream with the most channels, for subtitles, it is the first
subtitle stream. In the case where several streams of the same type
rate equally, the stream with the lowest index is chosen.
You can disable some of those defaults by using the "-vn/-an/-sn"
options. For full manual control, use the "-map" option, which disables
the defaults just described.
OPTIONS
All the numerical options, if not specified otherwise, accept a string
representing a number as input, which may be followed by one of the SI
unit prefixes, for example: 'K', 'M', or 'G'.
If 'i' is appended to the SI unit prefix, the complete prefix will be
interpreted as a unit prefix for binary multiples, which are based on
powers of 1024 instead of powers of 1000. Appending 'B' to the SI unit
prefix multiplies the value by 8. This allows using, for example: 'KB',
'MiB', 'G' and 'B' as number suffixes.
Options which do not take arguments are boolean options, and set the
corresponding value to true. They can be set to false by prefixing the
option name with "no". For example using "-nofoo" will set the boolean
option with name "foo" to false.
Stream specifiers
Some options are applied per-stream, e.g. bitrate or codec. Stream
specifiers are used to precisely specify which stream(s) a given option
belongs to.
A stream specifier is a string generally appended to the option name
and separated from it by a colon. E.g. "-codec:a:1 ac3" contains the
"a:1" stream specifier, which matches the second audio stream.
Therefore, it would select the ac3 codec for the second audio stream.
A stream specifier can match several streams, so that the option is
applied to all of them. E.g. the stream specifier in "-b:a 128k"
matches all audio streams.
An empty stream specifier matches all streams. For example, "-codec
copy" or "-codec: copy" would copy all the streams without reencoding.
Possible forms of stream specifiers are:
stream_index
Matches the stream with this index. E.g. "-threads:1 4" would set
the thread count for the second stream to 4.
stream_type[:stream_index]
stream_type is one of following: 'v' for video, 'a' for audio, 's'
for subtitle, 'd' for data, and 't' for attachments. If
stream_index is given, then it matches stream number stream_index
of this type. Otherwise, it matches all streams of this type.
p:program_id[:stream_index]
If stream_index is given, then it matches the stream with number
stream_index in the program with the id program_id. Otherwise, it
matches all streams in the program.
#stream_id or i:stream_id
Match the stream by stream id (e.g. PID in MPEG-TS container).
m:key[:value]
Matches streams with the metadata tag key having the specified
value. If value is not given, matches streams that contain the
given tag with any value.
Note that in ffmpeg, matching by metadata will only work properly
for input files.
Generic options
These options are shared amongst the ff* tools.
-L Show license.
-h, -?, -help, --help [arg]
Show help. An optional parameter may be specified to print help
about a specific item. If no argument is specified, only basic (non
advanced) tool options are shown.
Possible values of arg are:
long
Print advanced tool options in addition to the basic tool
options.
full
Print complete list of options, including shared and private
options for encoders, decoders, demuxers, muxers, filters, etc.
decoder=decoder_name
Print detailed information about the decoder named
decoder_name. Use the -decoders option to get a list of all
decoders.
encoder=encoder_name
Print detailed information about the encoder named
encoder_name. Use the -encoders option to get a list of all
encoders.
demuxer=demuxer_name
Print detailed information about the demuxer named
demuxer_name. Use the -formats option to get a list of all
demuxers and muxers.
muxer=muxer_name
Print detailed information about the muxer named muxer_name.
Use the -formats option to get a list of all muxers and
demuxers.
filter=filter_name
Print detailed information about the filter name filter_name.
Use the -filters option to get a list of all filters.
-version
Show version.
-formats
Show available formats (including devices).
-devices
Show available devices.
-codecs
Show all codecs known to libavcodec.
Note that the term 'codec' is used throughout this documentation as
a shortcut for what is more correctly called a media bitstream
format.
-decoders
Show available decoders.
-encoders
Show all available encoders.
-bsfs
Show available bitstream filters.
-protocols
Show available protocols.
-filters
Show available libavfilter filters.
-pix_fmts
Show available pixel formats.
-sample_fmts
Show available sample formats.
-layouts
Show channel names and standard channel layouts.
-colors
Show recognized color names.
-sources device[,opt1=val1[,opt2=val2]...]
Show autodetected sources of the intput device. Some devices may
provide system-dependent source names that cannot be autodetected.
The returned list cannot be assumed to be always complete.
ffmpeg -sources pulse,server=192.168.0.4
-sinks device[,opt1=val1[,opt2=val2]...]
Show autodetected sinks of the output device. Some devices may
provide system-dependent sink names that cannot be autodetected.
The returned list cannot be assumed to be always complete.
ffmpeg -sinks pulse,server=192.168.0.4
-loglevel [repeat+]loglevel | -v [repeat+]loglevel
Set the logging level used by the library. Adding "repeat+"
indicates that repeated log output should not be compressed to the
first line and the "Last message repeated n times" line will be
omitted. "repeat" can also be used alone. If "repeat" is used
alone, and with no prior loglevel set, the default loglevel will be
used. If multiple loglevel parameters are given, using 'repeat'
will not change the loglevel. loglevel is a number or a string
containing one of the following values:
quiet
Show nothing at all; be silent.
panic
Only show fatal errors which could lead the process to crash,
such as and assert failure. This is not currently used for
anything.
fatal
Only show fatal errors. These are errors after which the
process absolutely cannot continue after.
error
Show all errors, including ones which can be recovered from.
warning
Show all warnings and errors. Any message related to possibly
incorrect or unexpected events will be shown.
info
Show informative messages during processing. This is in
addition to warnings and errors. This is the default value.
verbose
Same as "info", except more verbose.
debug
Show everything, including debugging information.
By default the program logs to stderr, if coloring is supported by
the terminal, colors are used to mark errors and warnings. Log
coloring can be disabled setting the environment variable
AV_LOG_FORCE_NOCOLOR or NO_COLOR, or can be forced setting the
environment variable AV_LOG_FORCE_COLOR. The use of the
environment variable NO_COLOR is deprecated and will be dropped in
a following FFmpeg version.
-report
Dump full command line and console output to a file named
"program-YYYYMMDD-HHMMSS.log" in the current directory. This file
can be useful for bug reports. It also implies "-loglevel
verbose".
Setting the environment variable "FFREPORT" to any value has the
same effect. If the value is a ':'-separated key=value sequence,
these options will affect the report; options 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 option is 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 level
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
xop
fma4
3dnow
3dnowext
cmov
ARM
armv5te
armv6
armv6t2
vfp
vfpv3
neon
PowerPC
altivec
Specific Processors
pentium2
pentium3
pentium4
k6
k62
athlon
athlonxp
k8
-opencl_bench
Benchmark all available OpenCL devices and show the results. This
option is only available when FFmpeg has been compiled with
"--enable-opencl".
-opencl_options options (global)
Set OpenCL environment options. This option is only available when
FFmpeg has been compiled with "--enable-opencl".
options must be a list of key=value option pairs separated by ':'.
See the ``OpenCL Options'' section in the ffmpeg-utils manual for
the list of supported options.
AVOptions
These options are provided directly by the libavformat, libavdevice and
libavcodec libraries. To see the list of available AVOptions, use the
-help option. They are separated into two categories:
generic
These options can be set for any container, codec or device.
Generic options are listed under AVFormatContext options for
containers/devices and under AVCodecContext options for codecs.
private
These options are specific to the given container, device or codec.
Private options are listed under their corresponding
containers/devices/codecs.
For example to write an ID3v2.3 header instead of a default ID3v2.4 to
an MP3 file, use the id3v2_version private option of the MP3 muxer:
ffmpeg -i input.flac -id3v2_version 3 out.mp3
All codec AVOptions are per-stream, and thus a stream specifier should
be attached to them.
Note: the -nooption syntax cannot be used for boolean AVOptions, use
-option 0/-option 1.
Note: the old undocumented way of specifying per-stream AVOptions by
prepending v/a/s to the options name is now obsolete and will be
removed soon.
Main options
-f fmt (input/output)
Force input or output file format. The format is normally auto
detected for input files and guessed from the file extension for
output files, so this option is not needed in most cases.
-i filename (input)
input file name
-y (global)
Overwrite output files without asking.
-n (global)
Do not overwrite output files, and exit immediately if a specified
output file already exists.
-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 filename), stop
writing the output after its duration reaches duration.
duration may be a number in seconds, or in "hh:mm:ss[.xxx]" form.
-to and -t are mutually exclusive and -t has priority.
-to position (output)
Stop writing the output at position. position may be a number in
seconds, or in "hh:mm:ss[.xxx]" form.
-to and -t are mutually exclusive and -t has priority.
-fs limit_size (output)
Set the file size limit, expressed in bytes.
-ss position (input/output)
When used as an input option (before "-i"), seeks in this input
file to position. Note the 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 filename), decodes
but discards input until the timestamps reach position.
position may be either in seconds or in "hh:mm:ss[.xxx]" form.
-itsoffset offset (input)
Set the input time offset.
offset must be a time duration specification, see the Time duration
section in the ffmpeg-utils(1) manual.
The offset is added to the timestamps of the input files.
Specifying a positive offset means that the corresponding streams
are delayed by the time duration specified in offset.
-timestamp date (output)
Set the recording timestamp in the container.
date must be a time duration 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 or chapters. 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
-target type (output)
Specify target file type ("vcd", "svcd", "dvd", "dv", "dv50"). type
may be prefixed with "pal-", "ntsc-" or "film-" to use the
corresponding standard. All the format options (bitrate, codecs,
buffer sizes) are then set automatically. You can just type:
ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
Nevertheless you can specify additional options as long as you know
they do not conflict with the standard, as in:
ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
-dframes number (output)
Set the number of data frames to output. This is an alias for
"-frames:d".
-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.
-pre[:stream_specifier] preset_name (output,per-stream)
Specify the preset for matching stream(s).
-stats (global)
Print encoding progress/statistics. It is on by default, to
explicitly disable it you need to specify "-nostats".
-progress url (global)
Send program-friendly progress information to url.
Progress information is written approximately every second and at
the end of the encoding process. It is made of "key=value" lines.
key consists of only alphanumeric characters. The last key of a
sequence of progress information is always "progress".
-stdin
Enable interaction on standard input. On by default unless standard
input is used as an input. To explicitly disable interaction you
need to specify "-nostdin".
Disabling interaction on standard input is useful, for example, if
ffmpeg is in the background process group. Roughly the same result
can be achieved with "ffmpeg ... < /dev/null" but it requires a
shell.
-debug_ts (global)
Print timestamp information. It is off by default. This option is
mostly useful for testing and debugging purposes, and the output
format may change from one version to another, so it should not be
employed by portable scripts.
See also the option "-fdebug ts".
-attach filename (output)
Add an attachment to the output file. This is supported by a few
formats like Matroska for e.g. fonts used in rendering subtitles.
Attachments are implemented as a specific type of stream, so this
option will add a new stream to the file. It is then possible to
use per-stream options on this stream in the usual way. Attachment
streams created with this option will be created after all the
other streams (i.e. those created with "-map" or automatic
mappings).
Note that for Matroska you also have to set the mimetype metadata
tag:
ffmpeg -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv
(assuming that the attachment stream will be third in the output
file).
-dump_attachment[:stream_specifier] filename (input,per-stream)
Extract the matching attachment stream into a file named filename.
If filename is empty, then the value of the "filename" metadata tag
will be used.
E.g. to extract the first attachment to a file named 'out.ttf':
ffmpeg -dump_attachment:t:0 out.ttf -i INPUT
To extract all attachments to files determined by the "filename"
tag:
ffmpeg -dump_attachment:t "" -i INPUT
Technical note -- attachments are implemented as codec extradata,
so this option can actually be used to extract extradata from any
stream, not just attachments.
Video Options
-vframes number (output)
Set the number of video frames to output. This is an alias for
"-frames:v".
-r[:stream_specifier] fps (input/output,per-stream)
Set frame rate (Hz value, fraction or abbreviation).
As an input option, ignore any timestamps stored in the file and
instead generate timestamps assuming constant frame rate fps. This
is not the same as the -framerate option used for some input
formats like image2 or v4l2 (it used to be the same in older
versions of FFmpeg). If in doubt use -framerate instead of the
input option -r.
As an output option, duplicate or drop input frames to achieve
constant output frame rate fps.
-s[:stream_specifier] size (input/output,per-stream)
Set frame size.
As an input option, this is a shortcut for the video_size private
option, recognized by some demuxers for which the frame size is
either not stored in the file or is configurable -- e.g. raw video
or video grabbers.
As an output option, this inserts the "scale" video filter to the
end of the corresponding filtergraph. Please use the "scale" filter
directly to insert it at the beginning or some other place.
The format is wxh (default - same as source).
-aspect[:stream_specifier] aspect (output,per-stream)
Set the video display aspect ratio specified by aspect.
aspect can be a floating point number string, or a string of the
form num:den, where num and den are the numerator and denominator
of the aspect ratio. For example "4:3", "16:9", "1.3333", and
"1.7777" are valid argument values.
If used together with -vcodec copy, it will affect the aspect ratio
stored at container level, but not the aspect ratio stored in
encoded frames, if it exists.
-vn (output)
Disable video recording.
-vcodec codec (output)
Set the video codec. This is an alias for "-codec:v".
-pass[:stream_specifier] n (output,per-stream)
Select the pass number (1 or 2). It is used to do two-pass video
encoding. The statistics of the video are recorded in the first
pass into a log file (see also the option -passlogfile), and in the
second pass that log file is used to generate the video at the
exact requested bitrate. On pass 1, you may just deactivate audio
and set output to null, examples for Windows and Unix:
ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
-passlogfile[:stream_specifier] prefix (output,per-stream)
Set two-pass log file name prefix to prefix, the default file name
prefix is ``ffmpeg2pass''. The complete file name will be
PREFIX-N.log, where N is a number specific to the output stream
-vf filtergraph (output)
Create the filtergraph specified by filtergraph and use it to
filter the stream.
This is an alias for "-filter:v", see the -filter option.
Advanced Video options
-pix_fmt[:stream_specifier] format (input/output,per-stream)
Set pixel format. Use "-pix_fmts" to show all the supported pixel
formats. If the selected pixel format can not be selected, ffmpeg
will print a warning and select the best pixel format supported by
the encoder. If pix_fmt is prefixed by a "+", ffmpeg will exit
with an error if the requested pixel format can not be selected,
and automatic conversions inside filtergraphs are disabled. If
pix_fmt is a single "+", ffmpeg selects the same pixel format as
the input (or graph output) and automatic conversions are disabled.
-sws_flags flags (input/output)
Set SwScaler flags.
-vdt n
Discard threshold.
-rc_override[:stream_specifier] override (output,per-stream)
Rate control override for specific intervals, formatted as
"int,int,int" list separated with slashes. Two first values are the
beginning and end frame numbers, last one is quantizer to use if
positive, or quality factor if negative.
-ilme
Force interlacing support in encoder (MPEG-2 and MPEG-4 only). Use
this option if your input file is interlaced and you want to keep
the interlaced format for minimum losses. The alternative is to
deinterlace the input stream with -deinterlace, but deinterlacing
introduces losses.
-psnr
Calculate PSNR of compressed frames.
-vstats
Dump video coding statistics to vstats_HHMMSS.log.
-vstats_file file
Dump video coding statistics to file.
-top[:stream_specifier] n (output,per-stream)
top=1/bottom=0/auto=-1 field first
-dc precision
Intra_dc_precision.
-vtag fourcc/tag (output)
Force video tag/fourcc. This is an alias for "-tag:v".
-qphist (global)
Show QP histogram
-vbsf bitstream_filter
Deprecated see -bsf
-force_key_frames[:stream_specifier] time[,time...] (output,per-stream)
-force_key_frames[:stream_specifier] expr:expr (output,per-stream)
Force key frames at the specified timestamps, more precisely at the
first frames after each specified time.
If the argument is prefixed with "expr:", the string expr is
interpreted like an expression and is evaluated for each frame. A
key frame is forced in case the evaluation is non-zero.
If one of the times is ""chapters"[delta]", it is expanded into the
time of the beginning of all chapters in the file, shifted by
delta, expressed as a time in seconds. This option can be useful
to ensure that a seek point is present at a chapter mark or any
other designated place in the output file.
For example, to insert a key frame at 5 minutes, plus key frames
0.1 second before the beginning of every chapter:
-force_key_frames 0:05:00,chapters-0.1
The expression in expr can contain the following constants:
n the number of current processed frame, starting from 0
n_forced
the number of forced frames
prev_forced_n
the number of the previous forced frame, it is "NAN" when no
keyframe was forced yet
prev_forced_t
the time of the previous forced frame, it is "NAN" when no
keyframe was forced yet
t the time of the current processed frame
For example to force a key frame every 5 seconds, you can specify:
-force_key_frames expr:gte(t,n_forced*5)
To force a key frame 5 seconds after the time of the last forced
one, starting from second 13:
-force_key_frames expr:if(isnan(prev_forced_t),gte(t,13),gte(t,prev_forced_t+5))
Note that forcing too many keyframes is very harmful for the
lookahead algorithms of certain encoders: using fixed-GOP options
or similar would be more efficient.
-copyinkf[:stream_specifier] (output,per-stream)
When doing stream copy, copy also non-key frames found at the
beginning.
-hwaccel[:stream_specifier] hwaccel (input,per-stream)
Use hardware acceleration to decode the matching stream(s). The
allowed values of hwaccel are:
none
Do not use any hardware acceleration (the default).
auto
Automatically select the hardware acceleration method.
vda Use Apple VDA hardware acceleration.
vdpau
Use VDPAU (Video Decode and Presentation API for Unix) hardware
acceleration.
dxva2
Use DXVA2 (DirectX Video Acceleration) hardware acceleration.
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. Its exact meaning depends on the specific hardware
acceleration method chosen.
vdpau
For VDPAU, this option specifies the X11 display/screen to use.
If this option is not specified, the value of the DISPLAY
environment variable is used
dxva2
For DXVA2, this option should contain the number of the display
adapter to use. If this option is not specified, the default
adapter is used.
Audio Options
-aframes number (output)
Set the number of audio frames to output. This is an alias for
"-frames:a".
-ar[:stream_specifier] freq (input/output,per-stream)
Set the audio sampling frequency. For output streams it is set by
default to the frequency of the corresponding input stream. For
input streams this option only makes sense for audio grabbing
devices and raw demuxers and is mapped to the corresponding demuxer
options.
-aq q (output)
Set the audio quality (codec-specific, VBR). This is an alias for
-q:a.
-ac[:stream_specifier] channels (input/output,per-stream)
Set the number of audio channels. For output streams it is set by
default to the number of input audio channels. For input streams
this option only makes sense for audio grabbing devices and raw
demuxers and is mapped to the corresponding demuxer options.
-an (output)
Disable audio recording.
-acodec codec (input/output)
Set the audio codec. This is an alias for "-codec:a".
-sample_fmt[:stream_specifier] sample_fmt (output,per-stream)
Set the audio sample format. Use "-sample_fmts" to get a list of
supported sample formats.
-af filtergraph (output)
Create the filtergraph specified by filtergraph and use it to
filter the stream.
This is an alias for "-filter:a", see the -filter option.
Advanced Audio options
-atag fourcc/tag (output)
Force audio tag/fourcc. This is an alias for "-tag:a".
-absf bitstream_filter
Deprecated, see -bsf
-guess_layout_max channels (input,per-stream)
If some input channel layout is not known, try to guess only if it
corresponds to at most the specified number of channels. For
example, 2 tells to ffmpeg to recognize 1 channel as mono and 2
channels as stereo but not 6 channels as 5.1. The default is to
always try to guess. Use 0 to disable all guessing.
Subtitle options
-scodec codec (input/output)
Set the subtitle codec. This is an alias for "-codec:s".
-sn (output)
Disable subtitle recording.
-sbsf bitstream_filter
Deprecated, see -bsf
Advanced Subtitle options
-fix_sub_duration
Fix subtitles durations. For each subtitle, wait for the next
packet in the same stream and adjust the duration of the first to
avoid overlap. This is necessary with some subtitles codecs,
especially DVB subtitles, because the duration in the original
packet is only a rough estimate and the end is actually marked by
an empty subtitle frame. Failing to use this option when necessary
can result in exaggerated durations or muxing failures due to non-
monotonic timestamps.
Note that this option will delay the output of all data until the
next subtitle packet is decoded: it may increase memory consumption
and latency a lot.
-canvas_size size
Set the size of the canvas used to render subtitles.
Advanced options
-map
[-]input_file_id[:stream_specifier][,sync_file_id[:stream_specifier]] |
[linklabel] (output)
Designate one or more input streams as a source for the output
file. Each input stream is identified by the input file index
input_file_id and the input stream index input_stream_id within the
input file. Both indices start at 0. If specified,
sync_file_id:stream_specifier sets which input stream is used as a
presentation sync reference.
The first "-map" option on the command line specifies the source
for output stream 0, the second "-map" option specifies the source
for output stream 1, etc.
A "-" character before the stream identifier creates a "negative"
mapping. It disables matching streams from already created
mappings.
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 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.
-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.
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
-map_metadata[:metadata_spec_out] infile[:metadata_spec_in]
(output,per-metadata)
Set metadata information of the next output file from infile. Note
that those are file indices (zero-based), not filenames. Optional
metadata_spec_in/out parameters specify, which metadata to copy. A
metadata specifier can have the following forms:
g global metadata, i.e. metadata that applies to the whole file
s[:stream_spec]
per-stream metadata. stream_spec is a stream specifier as
described in the Stream specifiers chapter. In an input
metadata specifier, the first matching stream is copied from.
In an output metadata specifier, all matching streams are
copied to.
c:chapter_index
per-chapter metadata. chapter_index is the zero-based chapter
index.
p:program_index
per-program metadata. program_index is the zero-based program
index.
If metadata specifier is omitted, it defaults to global.
By default, global metadata is copied from the first input file,
per-stream and per-chapter metadata is copied along with
streams/chapters. These default mappings are disabled by creating
any mapping of the relevant type. A negative file index can be used
to create a dummy mapping that just disables automatic copying.
For example to copy metadata from the first stream of the input
file to global metadata of the output file:
ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3
To do the reverse, i.e. copy global metadata to all audio streams:
ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv
Note that simple 0 would work as well in this example, since global
metadata is assumed by default.
-map_chapters input_file_index (output)
Copy chapters from input file with index input_file_index to the
next output file. If no chapter mapping is specified, then chapters
are copied from the first input file with at least one chapter. Use
a negative file index to disable any chapter copying.
-benchmark (global)
Show benchmarking information at the end of an encode. Shows CPU
time used and maximum memory consumption. Maximum memory
consumption is not supported on all systems, it will usually
display as 0 if not supported.
-benchmark_all (global)
Show benchmarking information during the encode. Shows CPU time
used in various steps (audio/video encode/decode).
-timelimit duration (global)
Exit after ffmpeg has been running for duration seconds.
-dump (global)
Dump each input packet to stderr.
-hex (global)
When dumping packets, also dump the payload.
-re (input)
Read input at native frame rate. Mainly used to simulate a grab
device. or live input stream (e.g. when reading from a file).
Should not be used with actual grab devices or live input streams
(where it can cause packet loss). By default ffmpeg attempts to
read the input(s) as fast as possible. This option will slow down
the reading of the input(s) to the native frame rate of the
input(s). It is useful for real-time output (e.g. live streaming).
-loop_input
Loop over the input stream. Currently it works only for image
streams. This option is used for automatic FFserver testing. This
option is deprecated, use -loop 1.
-loop_output number_of_times
Repeatedly loop output for formats that support looping such as
animated GIF (0 will loop the output infinitely). This option is
deprecated, use -loop.
-vsync parameter
Video sync method. For compatibility reasons old values can be
specified as numbers. Newly added values will have to be specified
as strings always.
0, passthrough
Each frame is passed with its timestamp from the demuxer to the
muxer.
1, cfr
Frames will be duplicated and dropped to achieve exactly the
requested constant frame rate.
2, vfr
Frames are passed through with their timestamp or dropped so as
to prevent 2 frames from having the same timestamp.
drop
As passthrough but destroys all timestamps, making the muxer
generate fresh timestamps based on frame-rate.
-1, auto
Chooses between 1 and 2 depending on muxer capabilities. This
is the default method.
Note that the timestamps may be further modified by the muxer,
after this. For example, in the case that the format option
avoid_negative_ts is enabled.
With -map you can select from which stream the timestamps should be
taken. You can leave either video or audio unchanged and sync the
remaining stream(s) to the unchanged one.
-async samples_per_second
Audio sync method. "Stretches/squeezes" the audio stream to match
the timestamps, the parameter is the maximum samples per second by
which the audio is changed. -async 1 is a special case where only
the start of the audio stream is corrected without any later
correction.
Note that the timestamps may be further modified by the muxer,
after this. For example, in the case that the format option
avoid_negative_ts is enabled.
This option has been deprecated. Use the "aresample" audio filter
instead.
-copyts
Do not process input timestamps, but keep their values without
trying to sanitize them. In particular, do not remove the initial
start time offset value.
Note that, depending on the vsync option or on specific muxer
processing (e.g. in case the format option avoid_negative_ts is
enabled) the output timestamps may mismatch with the input
timestamps even when this option is selected.
-start_at_zero
When used with copyts, shift input timestamps so they start at
zero.
This means that using e.g. "-ss 50" will make output timestamps
start at 50 seconds, regardless of what timestamp the input file
started at.
-copytb mode
Specify how to set the encoder timebase when stream copying. mode
is an integer numeric value, and can assume one of the following
values:
1 Use the demuxer timebase.
The time base is copied to the output encoder from the
corresponding input demuxer. This is sometimes required to
avoid non monotonically increasing timestamps when copying
video streams with variable frame rate.
0 Use the decoder timebase.
The time base is copied to the output encoder from the
corresponding input decoder.
-1 Try to make the choice automatically, in order to generate a
sane output.
Default value is -1.
-shortest (output)
Finish encoding when the shortest input stream ends.
-dts_delta_threshold
Timestamp discontinuity delta threshold.
-muxdelay seconds (input)
Set the maximum demux-decode delay.
-muxpreload seconds (input)
Set the initial demux-decode delay.
-streamid output-stream-index:new-value (output)
Assign a new stream-id value to an output stream. This option
should be specified prior to the output filename to which it
applies. For the situation where multiple output files exist, a
streamid may be reassigned to a different value.
For example, to set the stream 0 PID to 33 and the stream 1 PID to
36 for an output mpegts file:
ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
-bsf[:stream_specifier] bitstream_filters (output,per-stream)
Set bitstream filters for matching streams. bitstream_filters is a
comma-separated list of bitstream filters. Use the "-bsfs" option
to get the list of bitstream filters.
ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264
ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt
-tag[:stream_specifier] codec_tag (input/output,per-stream)
Force a tag/fourcc for matching streams.
-timecode hh:mm:ssSEPff
Specify Timecode for writing. SEP is ':' for non drop timecode and
';' (or '.') for drop.
ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg
-filter_complex filtergraph (global)
Define a complex filtergraph, i.e. one with arbitrary number of
inputs and/or outputs. For simple graphs -- those with one input
and one output of the same type -- see the -filter options.
filtergraph is a description of the filtergraph, as described in
the ``Filtergraph syntax'' section of the ffmpeg-filters manual.
Input link labels must refer to input streams using the
"[file_index:stream_specifier]" syntax (i.e. the same as -map
uses). If stream_specifier matches multiple streams, the first one
will be used. An unlabeled input will be connected to the first
unused input stream of the matching type.
Output link labels are referred to with -map. Unlabeled outputs are
added to the first output file.
Note that with this option it is possible to use only lavfi sources
without normal input files.
For example, to overlay an image over video
ffmpeg -i video.mkv -i image.png -filter_complex '[0:v][1:v]overlay[out]' -map
'[out]' out.mkv
Here "[0:v]" refers to the first video stream in the first input
file, which is linked to the first (main) input of the overlay
filter. Similarly the first video stream in the second input is
linked to the second (overlay) input of overlay.
Assuming there is only one video stream in each input file, we can
omit input labels, so the above is equivalent to
ffmpeg -i video.mkv -i image.png -filter_complex 'overlay[out]' -map
'[out]' out.mkv
Furthermore we can omit the output label and the single output from
the filter graph will be added to the output file automatically, so
we can simply write
ffmpeg -i video.mkv -i image.png -filter_complex 'overlay' out.mkv
To generate 5 seconds of pure red video using lavfi "color" source:
ffmpeg -filter_complex 'color=c=red' -t 5 out.mkv
-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.
-override_ffserver (global)
Overrides the input specifications from ffserver. Using this option
you can map any input stream to ffserver and control many aspects
of the encoding from ffmpeg. Without this option ffmpeg will
transmit to ffserver what is requested by ffserver.
The option is intended for cases where features are needed that
cannot be specified to ffserver but can be to ffmpeg.
-discard (input)
Allows discarding specific streams or frames of streams at the
demuxer. Not all demuxers support this.
none
Discard no frame.
default
Default, which discards no frames.
noref
Discard all non-reference frames.
bidir
Discard all bidirectional frames.
nokey
Discard all frames excepts keyframes.
all Discard all frames.
As a special exception, you can use a bitmap subtitle stream as input:
it will be converted into a video with the same size as the largest
video in the file, or 720x576 if no video is present. Note that this is
an experimental and temporary solution. It will be removed once
libavfilter has proper support for subtitles.
For example, to hardcode subtitles on top of a DVB-T recording stored
in MPEG-TS format, delaying the subtitles by 1 second:
ffmpeg -i input.ts -filter_complex \
'[#0x2ef] setpts=PTS+1/TB [sub] ; [#0x2d0] [sub] overlay' \
-sn -map '#0x2dc' output.mkv
(0x2d0, 0x2dc and 0x2ef are the MPEG-TS PIDs of respectively the video,
audio and subtitles streams; 0:0, 0:3 and 0:7 would have worked too)
Preset files
A preset file contains a sequence of option=value pairs, one for each
line, specifying a sequence of options which would be awkward to
specify on the command line. Lines starting with the hash ('#')
character are ignored and are used to provide comments. Check the
presets directory in the FFmpeg source tree for examples.
Preset 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.
TIPS
· For streaming at very low bitrates, use a low frame rate and a
small GOP size. This is especially true for RealVideo where the
Linux player does not seem to be very fast, so it can miss frames.
An example is:
ffmpeg -g 3 -r 3 -t 10 -b:v 50k -s qcif -f rv10 /tmp/b.rm
· The parameter 'q' which is displayed while encoding is the current
quantizer. The value 1 indicates that a very good quality could be
achieved. The value 31 indicates the worst quality. If q=31 appears
too often, it means that the encoder cannot compress enough to meet
your bitrate. You must either increase the bitrate, decrease the
frame rate or decrease the frame size.
· If your computer is not fast enough, you can speed up the
compression at the expense of the compression ratio. You can use
'-me zero' to speed up motion estimation, and '-g 0' to disable
motion estimation completely (you have only I-frames, which means
it is about as good as JPEG compression).
· To have very low audio bitrates, reduce the sampling frequency
(down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
· To have a constant quality (but a variable bitrate), use the option
'-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
quality).
EXAMPLES
Preset files
A preset file contains a sequence of option=value pairs, one for each
line, specifying a sequence of options which can be specified also on
the command line. Lines starting with the hash ('#') character are
ignored and are used to provide comments. Empty lines are also ignored.
Check the presets directory in the FFmpeg source tree for examples.
Preset files are specified with the "pre" option, this option takes a
preset name as input. FFmpeg searches for a file named
preset_name.avpreset in the directories $AVCONV_DATADIR (if set), and
$HOME/.ffmpeg, and in the data directory defined at configuration time
(usually $PREFIX/share/ffmpeg) in that order. For example, if the
argument is "libx264-max", it will search for the file
libx264-max.avpreset.
Video and Audio grabbing
If you specify the input format and device then ffmpeg can grab video
and audio directly.
ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
Or with an ALSA audio source (mono input, card id 1) instead of OSS:
ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg
Note that you must activate the right video source and channel before
launching ffmpeg with any TV viewer such as
<http://linux.bytesex.org/xawtv/> by Gerd Knorr. You also have to set
the audio recording levels correctly with a standard mixer.
X11 grabbing
Grab the X11 display with ffmpeg via
ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0 /tmp/out.mpg
0.0 is display.screen number of your X11 server, same as the DISPLAY
environment variable.
ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0+10,20 /tmp/out.mpg
0.0 is display.screen number of your X11 server, same as the DISPLAY
environment variable. 10 is the x-offset and 20 the y-offset for the
grabbing.
Video and Audio file format conversion
Any supported file format and protocol can serve as input to ffmpeg:
Examples:
· You can use YUV files as input:
ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
It will use the files:
/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
The Y files use twice the resolution of the U and V files. They are
raw files, without header. They can be generated by all decent
video decoders. You must specify the size of the image with the -s
option if ffmpeg cannot guess it.
· You can input from a raw YUV420P file:
ffmpeg -i /tmp/test.yuv /tmp/out.avi
test.yuv is a file containing raw YUV planar data. Each frame is
composed of the Y plane followed by the U and V planes at half
vertical and horizontal resolution.
· You can output to a raw YUV420P file:
ffmpeg -i mydivx.avi hugefile.yuv
· You can set several input files and output files:
ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
Converts the audio file a.wav and the raw YUV video file a.yuv to
MPEG file a.mpg.
· You can also do audio and video conversions at the same time:
ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
Converts a.wav to MPEG audio at 22050 Hz sample rate.
· You can encode to several formats at the same time and define a
mapping from input stream to output streams:
ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2
Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits.
'-map file:index' specifies which input stream is used for each
output stream, in the order of the definition of output streams.
· You can transcode decrypted VOBs:
ffmpeg -i snatch_1.vob -f avi -c:v mpeg4 -b:v 800k -g 300 -bf 2 -c:a libmp3lame -b:a 128k snatch.avi
This is a typical DVD ripping example; the input is a VOB file, the
output an AVI file with MPEG-4 video and MP3 audio. Note that in
this command we use B-frames so the MPEG-4 stream is DivX5
compatible, and GOP size is 300 which means one intra frame every
10 seconds for 29.97fps input video. Furthermore, the audio stream
is MP3-encoded so you need to enable LAME support by passing
"--enable-libmp3lame" to configure. The mapping is particularly
useful for DVD transcoding to get the desired audio language.
NOTE: To see the supported input formats, use "ffmpeg -formats".
· 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 -vframes 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 -i foo-%03d.jpeg -r 12 -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 -i 'foo-*.jpeg' -r 12 -s WxH foo.avi
· You can put many streams of the same type in the output:
ffmpeg -i test1.avi -i test2.avi -map 1:1 -map 1:0 -map 0:1 -map 0:0 -c copy -y test12.nut
The resulting output file test12.nut will contain the first four
streams from the input files in reverse order.
· To force CBR video output:
ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
· The four options lmin, lmax, mblmin and mblmax use 'lambda' units,
but you may use the QP2LAMBDA constant to easily convert from 'q'
units:
ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
SEE ALSOffmpeg-all(1), ffplay(1), ffprobe(1), ffserver(1), ffmpeg-utils(1),
ffmpeg-scaler(1), ffmpeg-resampler(1), ffmpeg-codecs(1),
ffmpeg-bitstream-filters(1), ffmpeg-formats(1), ffmpeg-devices(1),
ffmpeg-protocols(1), ffmpeg-filters(1)AUTHORS
The FFmpeg developers.
For details about the authorship, see the Git history of the project
(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command git log in
the FFmpeg source directory, or browsing the online repository at
<http://source.ffmpeg.org>.
Maintainers for the specific components are listed in the file
MAINTAINERS in the source code tree.
2015-02-27 FFMPEG(1)
