ffmpeg-doc.texi

FFmpeg is an audio/video conversion tool. It includes libavcodec, the leading open source codec libr

\input texinfo @c -*- texinfo -*-

@settitle FFmpeg Documentation
@titlepage
@sp 7
@center @titlefont{FFmpeg Documentation}
@sp 3
@end titlepage


@chapter Introduction

FFmpeg is a very fast video and audio converter. It can also grab from
a live audio/video source.
  
The command line interface is designed to be intuitive, in the sense
that ffmpeg tries to figure out all the parameters, when
possible. You have usually to give only the target bitrate you want.

FFmpeg can also convert from any sample rate to any other, and resize
video on the fly with a high quality polyphase filter.

@chapter Quick Start

@c man begin EXAMPLES
@section Video and Audio grabbing

FFmpeg can use a video4linux compatible video source and any Open Sound
System audio source:

@example
ffmpeg /tmp/out.mpg 
@end example

Note that you must activate the right video source and channel before
launching ffmpeg. You can use any TV viewer such as xawtv
(@url{http://bytesex.org/xawtv/}) by Gerd Knorr which I find very
good. You must also set correctly the audio recording levels with a
standard mixer.

@section Video and Audio file format conversion

* ffmpeg can use any supported file format and protocol as input: 

Examples:

* You can input from YUV files:

@example
ffmpeg -i /tmp/test%d.Y /tmp/out.mpg 
@end example

It will use the files: 
@example
/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
@end example

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 @option{-s} option
if ffmpeg cannot guess it.

* You can input from a RAW YUV420P file:

@example
ffmpeg -i /tmp/test.yuv /tmp/out.avi
@end example

The RAW YUV420P is a file containing RAW YUV planar, for each frame first
come the Y plane followed by U and V planes, which are half vertical and
horizontal resolution.

* You can output to a RAW YUV420P file:

@example
ffmpeg -i mydivx.avi -o hugefile.yuv
@end example

* You can set several input files and output files:

@example
ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
@end example

Convert 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:

@example
ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
@end example

Convert the sample rate of a.wav to 22050 Hz and encode it to MPEG audio.

* You can encode to several formats at the same time and define a
mapping from input stream to output streams:

@example
ffmpeg -i /tmp/a.wav -ab 64 /tmp/a.mp2 -ab 128 /tmp/b.mp2 -map 0:0 -map 0:0
@end example

Convert a.wav to a.mp2 at 64 kbits and b.mp2 at 128 kbits. '-map
file:index' specify which input stream is used for each output
stream, in the order of the definition of output streams.

* You can transcode decrypted VOBs

@example
ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800 -g 300 -bf 2 -acodec mp3 -ab 128 snatch.avi
@end example

This is a typical DVD ripper example, input from a VOB file, output
to 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, GOP
size is 300 that means an INTRA frame every 10 seconds for 29.97 fps
input video.  Also the audio stream is MP3 encoded so you need LAME
support which is enabled using @code{--enable-mp3lame} when
configuring.  The mapping is particularly useful for DVD transcoding
to get the desired audio language.

NOTE: to see the supported input formats, use @code{ffmpeg -formats}.
@c man end

@chapter Invocation

@section Syntax

The generic syntax is:

@example 
@c man begin SYNOPSIS
ffmpeg [[options][@option{-i} @var{input_file}]]... @{[options] @var{output_file}@}...
@c man end
@end example
@c man begin 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 @option{-b 64} option, it sets the video
bitrate of the next file. 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 parameter for the outputs as the one
specified for the inputs.
@c man end

@c man begin OPTIONS
@section Main options

@table @option
@item -L
show license

@item -h
show help

@item -formats
show available formats, codecs, protocols, ...

@item -f fmt              
force format

@item -i filename         
input file name

@item -y                  
overwrite output files

@item -t duration         
set the recording time in seconds. @code{hh:mm:ss[.xxx]} syntax is also
supported.

@item -ss position
seek to given time position. @code{hh:mm:ss[.xxx]} syntax is also
supported.

@item -title string       
set the title

@item -author string      
set the author

@item -copyright string   
set the copyright

@item -comment string     
set the comment

@item -target type
specify target file type ("vcd", "svcd" or "dvd"). All the format
options (bitrate, codecs, buffer sizes) are automatically set by this
option. You can just type:

@example
ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
@end example

@item -hq
activate high quality settings

@item -itsoffset offset
set the input time offset in seconds. @code{[-]hh:mm:ss[.xxx]} syntax
is also supported.  This option affects all the input files that
follow it.  The offset is added to the input files' timestamps;
specifying a positive offset means that the corresponding streams are
delayed by 'offset' seconds.

@end table

@section Video Options

@table @option
@item -b bitrate
set the video bitrate in kbit/s (default = 200 kb/s)
@item -r fps           
set frame rate (default = 25)
@item -s size             
set frame size. The format is @samp{WxH} (default 160x128).  The
following abbreviations are recognized:
@table @samp
@item sqcif
128x96
@item qcif
176x144
@item cif
352x288
@item 4cif
704x576
@end table

@item -aspect aspect
set aspect ratio (4:3, 16:9 or 1.3333, 1.7777)
@item -croptop size
set top crop band size (in pixels)
@item -cropbottom size
set bottom crop band size (in pixels)
@item -cropleft size
set left crop band size (in pixels)
@item -cropright size
set right crop band size (in pixels)
@item -padtop size
set top pad band size (in pixels)
@item -padbottom size
set bottom pad band size (in pixels)
@item -padleft size
set left pad band size (in pixels)
@item -padright size
set right pad band size (in pixels)
@item -padcolor color
set right pad band size (hex). The value for pad color is expressed 
as a six digit hexidecimal number where the first two digits represent red, 
middle two digits green and last two digits blue. Defaults to 000000 (black)
@item -vn
disable video recording
@item -bt tolerance       
set video bitrate tolerance (in kbit/s)
@item -maxrate bitrate
set max video bitrate tolerance (in kbit/s)
@item -minrate bitrate
set min video bitrate tolerance (in kbit/s)
@item -bufsize size
set ratecontrol buffere size (in kbit)
@item -vcodec codec       
force video codec to @var{codec}. Use the @code{copy} special value to
tell that the raw codec data must be copied as is.
@item -sameq
use same video quality as source (implies VBR)

@item -pass n  
select the pass number (1 or 2). It is useful to do two pass
encoding. The statistics of the video are recorded in the first pass and
the video at the exact requested bit rate is generated in the second
pass.

@item -passlogfile file   
select two pass log file name to @var{file}.

@end table

@section Advanced Video Options

@table @option
@item -g gop_size         
set the group of picture size
@item -intra              
use only intra frames
@item -qscale q           
use fixed video quantiser scale (VBR)
@item -qmin q             
min video quantiser scale (VBR)
@item -qmax q             
max video quantiser scale (VBR)
@item -qdiff q            
max difference between the quantiser scale (VBR)
@item -qblur blur         
video quantiser scale blur (VBR)
@item -qcomp compression  
video quantiser scale compression (VBR)

@item -rc_init_cplx complexity
initial complexity for 1-pass encoding
@item -b_qfactor factor
qp factor between p and b frames
@item -i_qfactor factor
qp factor between p and i frames
@item -b_qoffset offset
qp offset between p and b frames
@item -i_qoffset offset
qp offset between p and i frames
@item -rc_eq equation
set rate control equation (@pxref{FFmpeg formula
evaluator}). Default is @code{tex^qComp}.
@item -rc_override override
rate control override for specific intervals
@item -me method
set motion estimation method to @var{method}. Available methods are
(from lower to best quality):
@table @samp
@item zero
Try just the (0, 0) vector.
@item phods
@item log
@item x1
@item epzs
(default method)
@item full
exhaustive search (slow and marginally better than epzs)
@end table

@item -dct_algo algo
set dct algorithm to @var{algo}. Available values are:
@table @samp
@item 0
FF_DCT_AUTO (default)
@item 1
FF_DCT_FASTINT
@item 2
FF_DCT_INT
@item 3
FF_DCT_MMX
@item 4
FF_DCT_MLIB
@item 5