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.
* To set the video bitrate of the output file to 64kbit/s:
ffmpeg -i input.avi -b 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.
By default, FFmpeg tries to convert as losslessly as possible: It
uses the same audio and video parameters for the outputs as the one
specified for the inputs.
OPTIONS
Generic options
These options are shared amongst the ff* tools.
-L
Show license.
-h, -?, -help, --help
Show help.
-version
Show version.
-formats
Show available formats.
The fields preceding the format names have the following meanings:
D
Decoding available
E
Encoding available
-codecs
Show available codecs.
The fields preceding the codec names have the following meanings:
D
Decoding available
E
Encoding available
V/A/S
Video/audio/subtitle codec
S
Codec supports slices
D
Codec supports direct rendering
T
Codec can handle input truncated at random locations instead of only at frame boundaries
-bsfs
Show available bitstream filters.
-protocols
Show available protocols.
-filters
Show available libavfilter filters.
-pix_fmts
Show available pixel formats.
-loglevelloglevel
Set the logging level used by the library.
loglevel is a number or a string containing one of the following values:
quiet
panic
fatal
error
warning
info
verbose
debug
Main options
-ffmt
Force format.
-ifilename
input file name
-y
Overwrite output files.
-tduration
Restrict the transcoded/captured video sequence
to the duration specified in seconds.
"hh:mm:ss[.xxx]" syntax is also supported.
-fslimit_size
Set the file size limit.
-ssposition
Seek to given time position in seconds.
"hh:mm:ss[.xxx]" syntax is also supported.
-itsoffsetoffset
Set the input time offset in seconds.
"[-]hh:mm:ss[.xxx]" syntax is also supported.
This option affects all the input files that follow it.
The offset is added to the timestamps of the input files.
Specifying a positive offset means that the corresponding
streams are delayed by 'offset' seconds.
-timestamptime
Set the timestamp.
-metadatakey=value
Set a metadata key/value pair.
For example, for setting the title in the output file:
Specify target file type (``vcd'', ``svcd'', ``dvd'', ``dv'', ``dv50'', ``pal-vcd'',
``ntsc-svcd'', ... ). 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:
Add a new subtitle stream to the current output stream.
-slangcode
Set the ISO 639 language code (3 letters) of the current subtitle stream.
Video Options
-bbitrate
Set the video bitrate in bit/s (default = 200 kb/s).
-vframesnumber
Set the number of video frames to record.
-rfps
Set frame rate (Hz value, fraction or abbreviation), (default = 25).
-ssize
Set frame size. The format is wxh (ffserver default = 160x128, ffmpeg default = same as source).
The following abbreviations are recognized:
sqcif
128x96
qcif
176x144
cif
352x288
4cif
704x576
16cif
1408x1152
qqvga
160x120
qvga
320x240
vga
640x480
svga
800x600
xga
1024x768
uxga
1600x1200
qxga
2048x1536
sxga
1280x1024
qsxga
2560x2048
hsxga
5120x4096
wvga
852x480
wxga
1366x768
wsxga
1600x1024
wuxga
1920x1200
woxga
2560x1600
wqsxga
3200x2048
wquxga
3840x2400
whsxga
6400x4096
whuxga
7680x4800
cga
320x200
ega
640x350
hd480
852x480
hd720
1280x720
hd1080
1920x1080
-aspectaspect
Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).
-croptopsize
Set top crop band size (in pixels).
-cropbottomsize
Set bottom crop band size (in pixels).
-cropleftsize
Set left crop band size (in pixels).
-croprightsize
Set right crop band size (in pixels).
-padtopsize
Set top pad band size (in pixels).
-padbottomsize
Set bottom pad band size (in pixels).
-padleftsize
Set left pad band size (in pixels).
-padrightsize
Set right pad band size (in pixels).
-padcolorhex_color
Set color of padded bands. The value for padcolor is expressed
as a six digit hexadecimal number where the first two digits
represent red, the middle two digits green and last two digits
blue (default = 000000 (black)).
-vn
Disable video recording.
-bttolerance
Set video bitrate tolerance (in bits, default 4000k).
Has a minimum value of: (target_bitrate/target_framerate).
In 1-pass mode, bitrate tolerance specifies how far ratecontrol is
willing to deviate from the target average bitrate value. This is
not related to min/max bitrate. Lowering tolerance too much has
an adverse effect on quality.
-maxratebitrate
Set max video bitrate (in bit/s).
Requires -bufsize to be set.
-minratebitrate
Set min video bitrate (in bit/s).
Most useful in setting up a CBR encode:
Force video codec to codec. Use the "copy" special value to
tell that the raw codec data must be copied as is.
-sameq
Use same video quality as source (implies VBR).
-passn
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:
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.
-newvideo
Add a new video stream to the current output stream.
-vlangcode
Set the ISO 639 language code (3 letters) of the current video stream.
Advanced Video Options
-pix_fmtformat
Set pixel format. Use 'list' as parameter to show all the supported
pixel formats.
-sws_flagsflags
Set SwScaler flags.
-ggop_size
Set the group of pictures size.
-intra
Use only intra frames.
-vdtn
Discard threshold.
-qscaleq
Use fixed video quantizer scale (VBR).
-qminq
minimum video quantizer scale (VBR)
-qmaxq
maximum video quantizer scale (VBR)
-qdiffq
maximum difference between the quantizer scales (VBR)
-qblurblur
video quantizer scale blur (VBR) (range 0.0 - 1.0)
-qcompcompression
video quantizer scale compression (VBR) (default 0.5).
Constant of ratecontrol equation. Recommended range for default rc_eq: 0.0-1.0
-lminlambda
minimum video lagrange factor (VBR)
-lmaxlambda
max video lagrange factor (VBR)
-mblminlambda
minimum macroblock quantizer scale (VBR)
-mblmaxlambda
maximum macroblock quantizer scale (VBR)
These four options (lmin, lmax, mblmin, 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
-rc_init_cplxcomplexity
initial complexity for single pass encoding
-b_qfactorfactor
qp factor between P- and B-frames
-i_qfactorfactor
qp factor between P- and I-frames
-b_qoffsetoffset
qp offset between P- and B-frames
-i_qoffsetoffset
qp offset between P- and I-frames
-rc_eqequation
Set rate control equation (default = "tex^qComp").
-rc_overrideoverride
rate control override for specific intervals
-me_methodmethod
Set motion estimation method to method.
Available methods are (from lowest to best quality):
zero
Try just the (0, 0) vector.
phods
log
x1
hex
umh
epzs
(default method)
full
exhaustive search (slow and marginally better than epzs)
-dct_algoalgo
Set DCT algorithm to algo. Available values are:
0
FF_DCT_AUTO (default)
1
FF_DCT_FASTINT
2
FF_DCT_INT
3
FF_DCT_MMX
4
FF_DCT_MLIB
5
FF_DCT_ALTIVEC
-idct_algoalgo
Set IDCT algorithm to algo. Available values are:
0
FF_IDCT_AUTO (default)
1
FF_IDCT_INT
2
FF_IDCT_SIMPLE
3
FF_IDCT_SIMPLEMMX
4
FF_IDCT_LIBMPEG2MMX
5
FF_IDCT_PS2
6
FF_IDCT_MLIB
7
FF_IDCT_ARM
8
FF_IDCT_ALTIVEC
9
FF_IDCT_SH4
10
FF_IDCT_SIMPLEARM
-ern
Set error resilience to n.
1
FF_ER_CAREFUL (default)
2
FF_ER_COMPLIANT
3
FF_ER_AGGRESSIVE
4
FF_ER_VERY_AGGRESSIVE
-ecbit_mask
Set error concealment to bit_mask. bit_mask is a bit mask of
the following values:
1
FF_EC_GUESS_MVS (default = enabled)
2
FF_EC_DEBLOCK (default = enabled)
-bfframes
Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
-mbdmode
macroblock decision
0
FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in FFmpeg).
1
FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
2
FF_MB_DECISION_RD: rate distortion
-4mv
Use four motion vector by macroblock (MPEG-4 only).
-part
Use data partitioning (MPEG-4 only).
-bugparam
Work around encoder bugs that are not auto-detected.
-strictstrictness
How strictly to follow the standards.
-aic
Enable Advanced intra coding (h263+).
-umv
Enable Unlimited Motion Vector (h263+)
-deinterlace
Deinterlace pictures.
-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_filefile
Dump video coding statistics to file.
-topn
top=1/bottom=0/auto=-1 field first
-dcprecision
Intra_dc_precision.
-vtagfourcc/tag
Force video tag/fourcc.
-qphist
Show QP histogram.
-vbsfbitstream_filter
Bitstream filters available are ``dump_extra'', ``remove_extra'', ``noise'', ``h264_mp4toannexb'', ``imxdump'', ``mjpegadump''.
Set the audio sampling frequency (default = 44100 Hz).
-abbitrate
Set the audio bitrate in bit/s (default = 64k).
-aqq
Set the audio quality (codec-specific, VBR).
-acchannels
Set the number of audio channels (default = 1).
-an
Disable audio recording.
-acodeccodec
Force audio codec to codec. Use the "copy" special value to
specify that the raw codec data must be copied as is.
-newaudio
Add a new audio track to the output file. If you want to specify parameters,
do so before "-newaudio" ("-acodec", "-ab", etc..).
Mapping will be done automatically, if the number of output streams is equal to
the number of input streams, else it will pick the first one that matches. You
can override the mapping using "-map" as usual.
Set stream mapping from input streams to output streams.
Just enumerate the input streams in the order you want them in the output.
sync_stream_id if specified sets the input stream to sync
against.
-map_meta_dataoutfile:infile
Set meta data information of outfile from infile.
-debug
Print specific debug info.
-benchmark
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.
-dump
Dump each input packet.
-hex
When dumping packets, also dump the payload.
-bitexact
Only use bit exact algorithms (for codec testing).
-pssize
Set RTP payload size in bytes.
-re
Read input at native frame rate. Mainly used to simulate a grab device.
-loop_input
Loop over the input stream. Currently it works only for image
streams. This option is used for automatic FFserver testing.
-loop_outputnumber_of_times
Repeatedly loop output for formats that support looping such as animated GIF
(0 will loop the output infinitely).
-threadscount
Thread count.
-vsyncparameter
Video sync method.
0 Each frame is passed with its timestamp from the demuxer to the muxer
1 Frames will be duplicated and dropped to achieve exactly the requested
constant framerate.
2 Frames are passed through with their timestamp or dropped so as to prevent
2 frames from having the same timestamp
-1 Chooses between 1 and 2 depending on muxer capabilities. This is the default method.
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.
-asyncsamples_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.
-copyts
Copy timestamps from input to output.
-shortest
Finish encoding when the shortest input stream ends.
-dts_delta_threshold
Timestamp discontinuity delta threshold.
-muxdelayseconds
Set the maximum demux-decode delay.
-muxpreloadseconds
Set the initial demux-decode delay.
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 ffpresets 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)
in that order. For example, if the argument is "libx264-max", it will
search for the file libx264-max.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 libx264" and use "-vpre max",
then it will search for the file libx264-max.ffpreset.
@anchor{FFmpeg formula evaluator}
FFmpeg formula evaluator
When evaluating a rate control string, FFmpeg uses an internal formula
evaluator.
The following binary operators are available: "+", "-",
"*", "/", "^".
The following unary operators are available: "+", "-",
"(...)".
The following statements are available: "ld", "st",
"while".
The following functions are available:
sinh(x)
cosh(x)
tanh(x)
sin(x)
cos(x)
tan(x)
atan(x)
asin(x)
acos(x)
exp(x)
log(x)
abs(x)
squish(x)
gauss(x)
mod(x, y)
max(x, y)
min(x, y)
eq(x, y)
gte(x, y)
gt(x, y)
lte(x, y)
lt(x, y)
bits2qp(bits)
qp2bits(qp)
The following constants are available:
PI
E
iTex
pTex
tex
mv
fCode
iCount
mcVar
var
isI
isP
isB
avgQP
qComp
avgIITex
avgPITex
avgPPTex
avgBPTex
avgTex
EXAMPLES
Video and Audio grabbing
FFmpeg can grab video and audio from devices given that you specify the input
format and device.
Note that you must activate the right video source and channel before
launching FFmpeg with any TV viewer such as xawtv
(<http://linux.bytesex.org/xawtv/>) by Gerd Knorr. You also
have to set the audio recording levels correctly with a
standard mixer.
X11 grabbing
FFmpeg can grab the X11 display.
ffmpeg -f x11grab -s cif -i :0.0 /tmp/out.mpg
0.0 is display.screen number of your X11 server, same as
the DISPLAY environment variable.
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:
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.
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:
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.
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.
* You can put many streams of the same type in the output:
In addition to the first video and audio streams, the resulting
output file test12.avi will contain the second video
and the second audio stream found in the input streams list.
The "-newvideo", "-newaudio" and "-newsubtitle"
options have to be specified immediately after the name of the output
file to which you want to add them.
SEE ALSO
ffserver(1), ffplay(1) and the HTML documentation of ffmpeg.