SYNOPSIS
ffmpeg [[infile options][-i infile]]... {[outfile options] outfile}...
DESCRIPTION
If no input file is given, audio/video grabbing is done.
As a general rule, options are applied to the next specified file. For
example, if you give the -b 64 option, it sets the video bitrate of the
next file. 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 speci‐
fied for the inputs.
OPTIONS
Main options
-L Show license.
-h Show help.
-formats
Show available formats, codecs, protocols, ...
-f fmt
Force format.
-i filename
input filename
-y Overwrite output files.
-t duration
Set the recording time in seconds. "hh:mm:ss[.xxx]" syntax is also
supported.
-ss position
Seek to given time position in seconds. "hh:mm:ss[.xxx]" syntax is
also supported.
-title string
Set the title.
-author string
Set the author.
-copyright string
Set the copyright.
-comment string
Set the comment.
-itsoffset offset
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.
Video Options
-b bitrate
Set the video bitrate in kbit/s (default = 200 kb/s).
-r fps
Set frame rate (default = 25).
-s size
Set frame size. The format is wxh (default = 160x128). The follow‐
ing abbreviations are recognized:
sqcif
128x96
qcif
176x144
cif 352x288
4cif
704x576
-aspect aspect
Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).
-croptop size
Set top crop band size (in pixels).
-cropbottom size
Set bottom crop band size (in pixels).
-cropleft size
Set left crop band size (in pixels).
-cropright size
Set right crop band size (in pixels).
-padtop size
Set top pad band size (in pixels).
-padbottom size
Set bottom pad band size (in pixels).
-bt tolerance
Set video bitrate tolerance (in kbit/s).
-maxrate bitrate
Set max video bitrate tolerance (in kbit/s).
-minrate bitrate
Set min video bitrate tolerance (in kbit/s).
-bufsize size
Set rate control buffer size (in kbit).
-vcodec codec
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).
-pass n
Select the pass number (1 or 2). It is useful to do two pass encod‐
ing. The statistics of the video are recorded in the first pass and
the video is generated at the exact requested bitrate in the second
pass.
-passlogfile file
Set two pass logfile name to file.
Advanced Video Options
-g gop_size
Set the group of pictures size.
-intra
Use only intra frames.
-qscale q
Use fixed video quantiser scale (VBR).
-qmin q
minimum video quantiser scale (VBR)
-qmax q
maximum video quantiser scale (VBR)
-qdiff q
maximum difference between the quantiser scales (VBR)
-qblur blur
video quantiser scale blur (VBR)
qp offset between P- and B-frames
-i_qoffset offset
qp offset between P- and I-frames
-rc_eq equation
Set rate control equation (default = "tex^qComp").
-rc_override override
rate control override for specific intervals
-me method
Set motion estimation method to method. Available methods are
(from lowest to best quality):
zero
Try just the (0, 0) vector.
phods
log
x1
epzs
(default method)
full
exhaustive search (slow and marginally better than epzs)
-dct_algo algo
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_algo algo
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
-er n
Set error resilience to n.
1 FF_ER_CAREFUL (default)
2 FF_ER_COMPLIANT
3 FF_ER_AGGRESSIVE
4 FF_ER_VERY_AGGRESSIVE
-ec bit_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)
-bf frames
Use ’frames’ B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
-mbd mode
macroblock decision
0 FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in FFm‐
peg).
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).
-bug param
Work around encoder bugs that are not auto-detected.
-strict strictness
How strictly to follow the standards.
-aic
Enable Advanced intra coding (h263+).
-umv
Enable Unlimited Motion Vector (h263+)
Dump video coding statistics to vstats_HHMMSS.log.
-vhook module
Insert video processing module. module contains the module name and
its parameters separated by spaces.
Audio Options
-ar freq
Set the audio sampling frequency (default = 44100 Hz).
-ab bitrate
Set the audio bitrate in kbit/s (default = 64).
-ac channels
Set the number of audio channels (default = 1).
-an Disable audio recording.
-acodec codec
Force audio codec to codec. Use the "copy" special value to specify
that the raw codec data must be copied as is.
Audio/Video grab options
-vd device
sEt video grab device (e.g. /dev/video0).
-vc channel
Set video grab channel (DV1394 only).
-tvstd standard
Set television standard (NTSC, PAL (SECAM)).
-dv1394
Set DV1394 grab.
-ad device
Set audio device (e.g. /dev/dsp).
Advanced options
-map file:stream
Set input stream mapping.
-debug
Print specific debug info.
-benchmark
-loop
Loop over the input stream. Currently it works only for image
streams. This option is used for automatic FFserver testing.
-loop_output number_of_times
Repeatedly loop output for formats that support looping such as
animated GIF (0 will loop the output infinitely).
-vsync parameter
Video sync method. Video will be stretched/squeezed to match the
timestamps, it is done by duplicating and dropping frames. 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 cor‐
rection.
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 functions are available:
sinh(x)
cosh(x)
tanh(x)
sin(x)
cos(x)
tan(x)
exp(x)
log(x)
squish(x)
gauss(x)
abs(x)
max(x, y)
min(x, y)
gt(x, y)
lt(x, y)
eq(x, y)
bits2qp(bits)
qp2bits(qp)
isB
avgQP
qComp
avgIITex
avgPITex
avgPPTex
avgBPTex
avgTex
EXAMPLES
Video and Audio grabbing
FFmpeg can use a video4linux compatible video source and any Open Sound
System audio source:
ffmpeg /tmp/out.mpg
Note that you must activate the right video source and channel before
launching FFmpeg with any TV viewer such as xawtv (<http://byte‐
sex.org/xawtv/>) by Gerd Knorr. You also have to set the audio record‐
ing levels correctly with a standard mixer.
Video and Audio file format conversion
* FFmpeg can use any supported file format and protocol as input:
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 com‐
posed 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:
* You can encode to several formats at the same time and define a map‐
ping from input stream to output streams:
ffmpeg -i /tmp/a.wav -ab 64 /tmp/a.mp2 -ab 128 /tmp/b.mp2 -map 0:0 -map 0:0
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 -vcodec mpeg4 -b 800 -g 300 -bf 2 -acodec mp3 -ab 128 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-mp3lame" to con‐
figure. The mapping is particularly useful for DVD transcoding to get
the desired audio language.
NOTE: To see the supported input formats, use "ffmpeg -formats".
SEE ALSO
ffserver(1), ffplay(1) and the HTML documentation of ffmpeg.
AUTHOR
Fabrice Bellard
2007-01-28 FFMPEG(1)
TechZilla.biz | TechZilla.info | SlicerUnderground | techzilla.50megs.com | Tohigherground | NextOnStage | EMUslax | GNUlinx | GamesOfDaPast | WorldCrimeWars | Fistula | Asus-Z81k | Riding-Gear | UniformDiscount | WorkWearIt | NuZilla