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\input texinfo @c -*- texinfo -*-
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@settitle FFmpeg Documentation
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@titlepage
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@sp 7
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@center @titlefont{FFmpeg Documentation}
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@sp 3
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@end titlepage
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@chapter Synopsis
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The generic syntax is:
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@example
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@c man begin SYNOPSIS
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ffmpeg [[infile options][@option{-i} @var{infile}]]... @{[outfile options] @var{outfile}@}...
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@c man end
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@end example
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@chapter Description
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@c man begin DESCRIPTION
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FFmpeg is a very fast video and audio converter. It can also grab from
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a live audio/video source.
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The command line interface is designed to be intuitive, in the sense
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that FFmpeg tries to figure out all parameters that can possibly be
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derived automatically. You usually only have to specify the target
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bitrate you want.
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FFmpeg can also convert from any sample rate to any other, and resize
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video on the fly with a high quality polyphase filter.
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As a general rule, options are applied to the next specified
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file. Therefore, order is important, and you can have the same
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option on the command line multiple times. Each occurrence is
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then applied to the next input or output file.
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* To set the video bitrate of the output file to 64kbit/s:
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@example
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ffmpeg -i input.avi -b 64k output.avi
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@end example
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* To force the frame rate of the output file to 24 fps:
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@example
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ffmpeg -i input.avi -r 24 output.avi
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@end example
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* To force the frame rate of the input file (valid for raw formats only)
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to 1 fps and the frame rate of the output file to 24 fps:
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@example
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ffmpeg -r 1 -i input.m2v -r 24 output.avi
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@end example
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The format option may be needed for raw input files.
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By default, FFmpeg tries to convert as losslessly as possible: It
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uses the same audio and video parameters for the outputs as the one
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specified for the inputs.
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@c man end DESCRIPTION
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@chapter Options
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@c man begin OPTIONS
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@include fftools-common-opts.texi
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@section Main options
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@table @option
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@item -f @var{fmt}
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Force format.
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@item -i @var{filename}
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input file name
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@item -y
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Overwrite output files.
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@item -t @var{duration}
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Restrict the transcoded/captured video sequence
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to the duration specified in seconds.
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@code{hh:mm:ss[.xxx]} syntax is also supported.
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@item -fs @var{limit_size}
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Set the file size limit.
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@item -ss @var{position}
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Seek to given time position in seconds.
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@code{hh:mm:ss[.xxx]} syntax is also supported.
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@item -itsoffset @var{offset}
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Set the input time offset in seconds.
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@code{[-]hh:mm:ss[.xxx]} syntax is also supported.
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This option affects all the input files that follow it.
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The offset is added to the timestamps of the input files.
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Specifying a positive offset means that the corresponding
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streams are delayed by 'offset' seconds.
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@item -timestamp @var{time}
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Set the recording timestamp in the container.
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The syntax for @var{time} is:
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@example
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now|([(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH[:MM[:SS[.m...]]])|(HH[MM[SS[.m...]]]))[Z|z])
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@end example
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If the value is "now" it takes the current time.
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Time is local time unless 'Z' or 'z' is appended, in which case it is
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interpreted as UTC.
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If the year-month-day part is not specified it takes the current
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year-month-day.
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@item -metadata @var{key}=@var{value}
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Set a metadata key/value pair.
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For example, for setting the title in the output file:
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@example
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ffmpeg -i in.avi -metadata title="my title" out.flv
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@end example
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@item -v @var{number}
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Set the logging verbosity level.
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@item -target @var{type}
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Specify target file type ("vcd", "svcd", "dvd", "dv", "dv50", "pal-vcd",
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"ntsc-svcd", ... ). All the format options (bitrate, codecs,
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buffer sizes) are then set automatically. You can just type:
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@example
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ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
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@end example
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Nevertheless you can specify additional options as long as you know
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they do not conflict with the standard, as in:
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@example
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ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
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@end example
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@item -dframes @var{number}
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Set the number of data frames to record.
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@item -scodec @var{codec}
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Force subtitle codec ('copy' to copy stream).
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@item -newsubtitle
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Add a new subtitle stream to the current output stream.
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@item -slang @var{code}
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Set the ISO 639 language code (3 letters) of the current subtitle stream.
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@end table
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@section Video Options
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@table @option
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@item -b @var{bitrate}
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Set the video bitrate in bit/s (default = 200 kb/s).
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@item -vframes @var{number}
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Set the number of video frames to record.
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@item -r @var{fps}
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Set frame rate (Hz value, fraction or abbreviation), (default = 25).
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@item -s @var{size}
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Set frame size. The format is @samp{wxh} (ffserver default = 160x128, ffmpeg default = same as source).
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The following abbreviations are recognized:
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@table @samp
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@item sqcif
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128x96
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@item qcif
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176x144
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@item cif
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352x288
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@item 4cif
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704x576
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@item 16cif
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1408x1152
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@item qqvga
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160x120
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@item qvga
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320x240
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@item vga
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640x480
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@item svga
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800x600
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@item xga
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1024x768
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@item uxga
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1600x1200
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@item qxga
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2048x1536
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@item sxga
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1280x1024
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@item qsxga
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2560x2048
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@item hsxga
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5120x4096
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@item wvga
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852x480
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@item wxga
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1366x768
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@item wsxga
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1600x1024
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@item wuxga
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1920x1200
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@item woxga
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2560x1600
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@item wqsxga
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3200x2048
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@item wquxga
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3840x2400
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@item whsxga
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6400x4096
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@item whuxga
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7680x4800
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@item cga
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320x200
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@item ega
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640x350
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@item hd480
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852x480
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@item hd720
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1280x720
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@item hd1080
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1920x1080
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@end table
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@item -aspect @var{aspect}
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Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).
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@item -croptop @var{size}
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@item -cropbottom @var{size}
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@item -cropleft @var{size}
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@item -cropright @var{size}
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All the crop options have been removed. Use -vf
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crop=width:height:x:y instead.
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@item -padtop @var{size}
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@item -padbottom @var{size}
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@item -padleft @var{size}
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@item -padright @var{size}
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@item -padcolor @var{hex_color}
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All the pad options have been removed. Use -vf
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pad=width:height:x:y:color instead.
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@item -vn
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Disable video recording.
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@item -bt @var{tolerance}
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Set video bitrate tolerance (in bits, default 4000k).
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Has a minimum value of: (target_bitrate/target_framerate).
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In 1-pass mode, bitrate tolerance specifies how far ratecontrol is
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willing to deviate from the target average bitrate value. This is
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not related to min/max bitrate. Lowering tolerance too much has
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an adverse effect on quality.
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@item -maxrate @var{bitrate}
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Set max video bitrate (in bit/s).
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Requires -bufsize to be set.
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@item -minrate @var{bitrate}
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Set min video bitrate (in bit/s).
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Most useful in setting up a CBR encode:
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@example
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ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
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@end example
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It is of little use elsewise.
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@item -bufsize @var{size}
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Set video buffer verifier buffer size (in bits).
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@item -vcodec @var{codec}
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Force video codec to @var{codec}. Use the @code{copy} special value to
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tell that the raw codec data must be copied as is.
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@item -sameq
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Use same video quality as source (implies VBR).
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@item -pass @var{n}
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Select the pass number (1 or 2). It is used to do two-pass
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video encoding. The statistics of the video are recorded in the first
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pass into a log file (see also the option -passlogfile),
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and in the second pass that log file is used to generate the video
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at the exact requested bitrate.
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On pass 1, you may just deactivate audio and set output to null,
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examples for Windows and Unix:
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@example
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ffmpeg -i foo.mov -vcodec libxvid -pass 1 -an -f rawvideo -y NUL
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ffmpeg -i foo.mov -vcodec libxvid -pass 1 -an -f rawvideo -y /dev/null
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@end example
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@item -passlogfile @var{prefix}
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Set two-pass log file name prefix to @var{prefix}, the default file name
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prefix is ``ffmpeg2pass''. The complete file name will be
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@file{PREFIX-N.log}, where N is a number specific to the output
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stream.
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@item -newvideo
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Add a new video stream to the current output stream.
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@item -vlang @var{code}
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Set the ISO 639 language code (3 letters) of the current video stream.
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@item -vf @var{filter_graph}
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@var{filter_graph} is a description of the filter graph to apply to
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the input video.
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Use the option "-filters" to show all the available filters (including
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also sources and sinks).
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@end table
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@section Advanced Video Options
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@table @option
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@item -pix_fmt @var{format}
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Set pixel format. Use 'list' as parameter to show all the supported
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pixel formats.
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@item -sws_flags @var{flags}
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Set SwScaler flags.
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@item -g @var{gop_size}
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Set the group of pictures size.
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@item -intra
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Use only intra frames.
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@item -vdt @var{n}
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Discard threshold.
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@item -qscale @var{q}
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Use fixed video quantizer scale (VBR).
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@item -qmin @var{q}
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minimum video quantizer scale (VBR)
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@item -qmax @var{q}
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maximum video quantizer scale (VBR)
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@item -qdiff @var{q}
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maximum difference between the quantizer scales (VBR)
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@item -qblur @var{blur}
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video quantizer scale blur (VBR) (range 0.0 - 1.0)
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@item -qcomp @var{compression}
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video quantizer scale compression (VBR) (default 0.5).
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Constant of ratecontrol equation. Recommended range for default rc_eq: 0.0-1.0
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@item -lmin @var{lambda}
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minimum video lagrange factor (VBR)
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@item -lmax @var{lambda}
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max video lagrange factor (VBR)
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@item -mblmin @var{lambda}
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minimum macroblock quantizer scale (VBR)
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@item -mblmax @var{lambda}
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maximum macroblock quantizer scale (VBR)
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These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
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but you may use the QP2LAMBDA constant to easily convert from 'q' units:
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@example
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ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
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@end example
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@item -rc_init_cplx @var{complexity}
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initial complexity for single pass encoding
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@item -b_qfactor @var{factor}
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qp factor between P- and B-frames
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@item -i_qfactor @var{factor}
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qp factor between P- and I-frames
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@item -b_qoffset @var{offset}
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qp offset between P- and B-frames
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@item -i_qoffset @var{offset}
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qp offset between P- and I-frames
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@item -rc_eq @var{equation}
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Set rate control equation (@pxref{FFmpeg formula
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evaluator}) (default = @code{tex^qComp}).
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@item -rc_override @var{override}
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rate control override for specific intervals
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@item -me_method @var{method}
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Set motion estimation method to @var{method}.
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Available methods are (from lowest to best quality):
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@table @samp
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@item zero
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Try just the (0, 0) vector.
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@item phods
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@item log
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@item x1
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@item hex
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@item umh
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@item epzs
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(default method)
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@item full
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exhaustive search (slow and marginally better than epzs)
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@end table
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@item -dct_algo @var{algo}
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Set DCT algorithm to @var{algo}. Available values are:
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@table @samp
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@item 0
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FF_DCT_AUTO (default)
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@item 1
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FF_DCT_FASTINT
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@item 2
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FF_DCT_INT
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@item 3
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FF_DCT_MMX
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@item 4
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FF_DCT_MLIB
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@item 5
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FF_DCT_ALTIVEC
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@end table
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@item -idct_algo @var{algo}
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Set IDCT algorithm to @var{algo}. Available values are:
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@table @samp
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@item 0
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FF_IDCT_AUTO (default)
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@item 1
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FF_IDCT_INT
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@item 2
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FF_IDCT_SIMPLE
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@item 3
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FF_IDCT_SIMPLEMMX
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@item 4
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FF_IDCT_LIBMPEG2MMX
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@item 5
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FF_IDCT_PS2
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@item 6
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FF_IDCT_MLIB
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@item 7
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FF_IDCT_ARM
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@item 8
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FF_IDCT_ALTIVEC
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@item 9
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FF_IDCT_SH4
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@item 10
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FF_IDCT_SIMPLEARM
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@end table
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@item -er @var{n}
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Set error resilience to @var{n}.
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@table @samp
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@item 1
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FF_ER_CAREFUL (default)
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@item 2
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FF_ER_COMPLIANT
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@item 3
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FF_ER_AGGRESSIVE
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@item 4
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FF_ER_VERY_AGGRESSIVE
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@end table
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@item -ec @var{bit_mask}
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Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
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the following values:
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@table @samp
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@item 1
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FF_EC_GUESS_MVS (default = enabled)
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@item 2
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FF_EC_DEBLOCK (default = enabled)
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@end table
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@item -bf @var{frames}
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Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
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@item -mbd @var{mode}
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macroblock decision
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@table @samp
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@item 0
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FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in FFmpeg).
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@item 1
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FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
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@item 2
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FF_MB_DECISION_RD: rate distortion
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@end table
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@item -4mv
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Use four motion vector by macroblock (MPEG-4 only).
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@item -part
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Use data partitioning (MPEG-4 only).
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@item -bug @var{param}
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Work around encoder bugs that are not auto-detected.
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@item -strict @var{strictness}
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How strictly to follow the standards.
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@item -aic
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Enable Advanced intra coding (h263+).
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@item -umv
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Enable Unlimited Motion Vector (h263+)
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@item -deinterlace
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Deinterlace pictures.
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@item -ilme
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Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
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Use this option if your input file is interlaced and you want
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to keep the interlaced format for minimum losses.
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The alternative is to deinterlace the input stream with
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@option{-deinterlace}, but deinterlacing introduces losses.
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@item -psnr
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Calculate PSNR of compressed frames.
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@item -vstats
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Dump video coding statistics to @file{vstats_HHMMSS.log}.
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@item -vstats_file @var{file}
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Dump video coding statistics to @var{file}.
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@item -top @var{n}
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top=1/bottom=0/auto=-1 field first
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@item -dc @var{precision}
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Intra_dc_precision.
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@item -vtag @var{fourcc/tag}
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Force video tag/fourcc.
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@item -qphist
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Show QP histogram.
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@item -vbsf @var{bitstream_filter}
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Bitstream filters available are "dump_extra", "remove_extra", "noise", "h264_mp4toannexb", "imxdump", "mjpegadump".
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@example
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ffmpeg -i h264.mp4 -vcodec copy -vbsf h264_mp4toannexb -an out.h264
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@end example
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@end table
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@section Audio Options
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@table @option
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@item -aframes @var{number}
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Set the number of audio frames to record.
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@item -ar @var{freq}
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Set the audio sampling frequency (default = 44100 Hz).
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@item -ab @var{bitrate}
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Set the audio bitrate in bit/s (default = 64k).
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@item -aq @var{q}
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Set the audio quality (codec-specific, VBR).
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@item -ac @var{channels}
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Set the number of audio channels. For input streams it is set by
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default to 1, for output streams it is set by default to the same
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number of audio channels in input. If the input file has audio streams
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with different channel count, the behaviour is undefined.
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@item -an
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Disable audio recording.
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@item -acodec @var{codec}
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Force audio codec to @var{codec}. Use the @code{copy} special value to
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specify that the raw codec data must be copied as is.
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@item -newaudio
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Add a new audio track to the output file. If you want to specify parameters,
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do so before @code{-newaudio} (@code{-acodec}, @code{-ab}, etc..).
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Mapping will be done automatically, if the number of output streams is equal to
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the number of input streams, else it will pick the first one that matches. You
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can override the mapping using @code{-map} as usual.
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Example:
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@example
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ffmpeg -i file.mpg -vcodec copy -acodec ac3 -ab 384k test.mpg -acodec mp2 -ab 192k -newaudio
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@end example
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@item -alang @var{code}
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Set the ISO 639 language code (3 letters) of the current audio stream.
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@end table
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@section Advanced Audio options:
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@table @option
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@item -atag @var{fourcc/tag}
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Force audio tag/fourcc.
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@item -absf @var{bitstream_filter}
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Bitstream filters available are "dump_extra", "remove_extra", "noise", "mp3comp", "mp3decomp".
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@end table
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@section Subtitle options:
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@table @option
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@item -scodec @var{codec}
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Force subtitle codec ('copy' to copy stream).
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@item -newsubtitle
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Add a new subtitle stream to the current output stream.
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@item -slang @var{code}
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Set the ISO 639 language code (3 letters) of the current subtitle stream.
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@item -sn
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Disable subtitle recording.
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@item -sbsf @var{bitstream_filter}
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Bitstream filters available are "mov2textsub", "text2movsub".
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@example
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ffmpeg -i file.mov -an -vn -sbsf mov2textsub -scodec copy -f rawvideo sub.txt
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@end example
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@end table
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@section Audio/Video grab options
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@table @option
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@item -vc @var{channel}
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Set video grab channel (DV1394 only).
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@item -tvstd @var{standard}
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Set television standard (NTSC, PAL (SECAM)).
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@item -isync
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Synchronize read on input.
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@end table
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@section Advanced options
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@table @option
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@item -map @var{input_stream_id}[:@var{sync_stream_id}]
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Set stream mapping from input streams to output streams.
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Just enumerate the input streams in the order you want them in the output.
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@var{sync_stream_id} if specified sets the input stream to sync
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against.
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@item -map_meta_data @var{outfile}:@var{infile}
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Set meta data information of @var{outfile} from @var{infile}.
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@item -debug
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Print specific debug info.
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@item -benchmark
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Show benchmarking information at the end of an encode.
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Shows CPU time used and maximum memory consumption.
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Maximum memory consumption is not supported on all systems,
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it will usually display as 0 if not supported.
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@item -dump
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Dump each input packet.
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@item -hex
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When dumping packets, also dump the payload.
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@item -bitexact
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Only use bit exact algorithms (for codec testing).
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@item -ps @var{size}
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Set RTP payload size in bytes.
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@item -re
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Read input at native frame rate. Mainly used to simulate a grab device.
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@item -loop_input
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Loop over the input stream. Currently it works only for image
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streams. This option is used for automatic FFserver testing.
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@item -loop_output @var{number_of_times}
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Repeatedly loop output for formats that support looping such as animated GIF
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(0 will loop the output infinitely).
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@item -threads @var{count}
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Thread count.
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@item -vsync @var{parameter}
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Video sync method.
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0   Each frame is passed with its timestamp from the demuxer to the muxer
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1   Frames will be duplicated and dropped to achieve exactly the requested
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    constant framerate.
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2   Frames are passed through with their timestamp or dropped so as to prevent
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    2 frames from having the same timestamp
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-1  Chooses between 1 and 2 depending on muxer capabilities. This is the default method.
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With -map you can select from
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which stream the timestamps should be taken. You can leave either video or
621
audio unchanged and sync the remaining stream(s) to the unchanged one.
622
@item -async @var{samples_per_second}
623
Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
624
the parameter is the maximum samples per second by which the audio is changed.
625
-async 1 is a special case where only the start of the audio stream is corrected
626
without any later correction.
627
@item -copyts
628
Copy timestamps from input to output.
629
@item -shortest
630
Finish encoding when the shortest input stream ends.
631
@item -dts_delta_threshold
632
Timestamp discontinuity delta threshold.
633
@item -muxdelay @var{seconds}
634
Set the maximum demux-decode delay.
635
@item -muxpreload @var{seconds}
636
Set the initial demux-decode delay.
637
@item -streamid @var{output-stream-index}:@var{new-value}
638
Assign a new value to a stream's stream-id field in the next output file.
639
All stream-id fields are reset to default for each output file.
640

    
641
For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
642
an output mpegts file:
643
@example
644
ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
645
@end example
646
@end table
647

    
648
@section Preset files
649

    
650
A preset file contains a sequence of @var{option}=@var{value} pairs,
651
one for each line, specifying a sequence of options which would be
652
awkward to specify on the command line. Lines starting with the hash
653
('#') character are ignored and are used to provide comments. Check
654
the @file{ffpresets} directory in the FFmpeg source tree for examples.
655

    
656
Preset files are specified with the @code{vpre}, @code{apre},
657
@code{spre}, and @code{fpre} options. The @code{fpre} option takes the
658
filename of the preset instead of a preset name as input and can be
659
used for any kind of codec. For the @code{vpre}, @code{apre}, and
660
@code{spre} options, the options specified in a preset file are
661
applied to the currently selected codec of the same type as the preset
662
option.
663

    
664
The argument passed to the @code{vpre}, @code{apre}, and @code{spre}
665
preset options identifies the preset file to use according to the
666
following rules:
667

    
668
First ffmpeg searches for a file named @var{arg}.ffpreset in the
669
directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
670
the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg})
671
in that order. For example, if the argument is @code{libx264-max}, it will
672
search for the file @file{libx264-max.ffpreset}.
673

    
674
If no such file is found, then ffmpeg will search for a file named
675
@var{codec_name}-@var{arg}.ffpreset in the above-mentioned
676
directories, where @var{codec_name} is the name of the codec to which
677
the preset file options will be applied. For example, if you select
678
the video codec with @code{-vcodec libx264} and use @code{-vpre max},
679
then it will search for the file @file{libx264-max.ffpreset}.
680

    
681
@anchor{FFmpeg formula evaluator}
682
@section FFmpeg formula evaluator
683

    
684
When evaluating a rate control string, FFmpeg uses an internal formula
685
evaluator.
686

    
687
The following binary operators are available: @code{+}, @code{-},
688
@code{*}, @code{/}, @code{^}.
689

    
690
The following unary operators are available: @code{+}, @code{-},
691
@code{(...)}.
692

    
693
The following statements are available: @code{ld}, @code{st},
694
@code{while}.
695

    
696
The following functions are available:
697
@table @var
698
@item sinh(x)
699
@item cosh(x)
700
@item tanh(x)
701
@item sin(x)
702
@item cos(x)
703
@item tan(x)
704
@item atan(x)
705
@item asin(x)
706
@item acos(x)
707
@item exp(x)
708
@item log(x)
709
@item abs(x)
710
@item squish(x)
711
@item gauss(x)
712
@item mod(x, y)
713
@item max(x, y)
714
@item min(x, y)
715
@item eq(x, y)
716
@item gte(x, y)
717
@item gt(x, y)
718
@item lte(x, y)
719
@item lt(x, y)
720
@item bits2qp(bits)
721
@item qp2bits(qp)
722
@end table
723

    
724
The following constants are available:
725
@table @var
726
@item PI
727
@item E
728
@item iTex
729
@item pTex
730
@item tex
731
@item mv
732
@item fCode
733
@item iCount
734
@item mcVar
735
@item var
736
@item isI
737
@item isP
738
@item isB
739
@item avgQP
740
@item qComp
741
@item avgIITex
742
@item avgPITex
743
@item avgPPTex
744
@item avgBPTex
745
@item avgTex
746
@end table
747

    
748
@c man end
749

    
750
@chapter Tips
751
@c man begin TIPS
752

    
753
@itemize
754
@item
755
For streaming at very low bitrate application, use a low frame rate
756
and a small GOP size. This is especially true for RealVideo where
757
the Linux player does not seem to be very fast, so it can miss
758
frames. An example is:
759

    
760
@example
761
ffmpeg -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
762
@end example
763

    
764
@item
765
The parameter 'q' which is displayed while encoding is the current
766
quantizer. The value 1 indicates that a very good quality could
767
be achieved. The value 31 indicates the worst quality. If q=31 appears
768
too often, it means that the encoder cannot compress enough to meet
769
your bitrate. You must either increase the bitrate, decrease the
770
frame rate or decrease the frame size.
771

    
772
@item
773
If your computer is not fast enough, you can speed up the
774
compression at the expense of the compression ratio. You can use
775
'-me zero' to speed up motion estimation, and '-intra' to disable
776
motion estimation completely (you have only I-frames, which means it
777
is about as good as JPEG compression).
778

    
779
@item
780
To have very low audio bitrates, reduce the sampling frequency
781
(down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
782

    
783
@item
784
To have a constant quality (but a variable bitrate), use the option
785
'-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
786
quality).
787

    
788
@item
789
When converting video files, you can use the '-sameq' option which
790
uses the same quality factor in the encoder as in the decoder.
791
It allows almost lossless encoding.
792

    
793
@end itemize
794
@c man end TIPS
795

    
796
@chapter Examples
797
@c man begin EXAMPLES
798

    
799
@section Video and Audio grabbing
800

    
801
FFmpeg can grab video and audio from devices given that you specify the input
802
format and device.
803

    
804
@example
805
ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
806
@end example
807

    
808
Note that you must activate the right video source and channel before
809
launching FFmpeg with any TV viewer such as xawtv
810
(@url{http://linux.bytesex.org/xawtv/}) by Gerd Knorr. You also
811
have to set the audio recording levels correctly with a
812
standard mixer.
813

    
814
@section X11 grabbing
815

    
816
FFmpeg can grab the X11 display.
817

    
818
@example
819
ffmpeg -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
820
@end example
821

    
822
0.0 is display.screen number of your X11 server, same as
823
the DISPLAY environment variable.
824

    
825
@example
826
ffmpeg -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
827
@end example
828

    
829
0.0 is display.screen number of your X11 server, same as the DISPLAY environment
830
variable. 10 is the x-offset and 20 the y-offset for the grabbing.
831

    
832
@section Video and Audio file format conversion
833

    
834
* FFmpeg can use any supported file format and protocol as input:
835

    
836
Examples:
837

    
838
* You can use YUV files as input:
839

    
840
@example
841
ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
842
@end example
843

    
844
It will use the files:
845
@example
846
/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
847
/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
848
@end example
849

    
850
The Y files use twice the resolution of the U and V files. They are
851
raw files, without header. They can be generated by all decent video
852
decoders. You must specify the size of the image with the @option{-s} option
853
if FFmpeg cannot guess it.
854

    
855
* You can input from a raw YUV420P file:
856

    
857
@example
858
ffmpeg -i /tmp/test.yuv /tmp/out.avi
859
@end example
860

    
861
test.yuv is a file containing raw YUV planar data. Each frame is composed
862
of the Y plane followed by the U and V planes at half vertical and
863
horizontal resolution.
864

    
865
* You can output to a raw YUV420P file:
866

    
867
@example
868
ffmpeg -i mydivx.avi hugefile.yuv
869
@end example
870

    
871
* You can set several input files and output files:
872

    
873
@example
874
ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
875
@end example
876

    
877
Converts the audio file a.wav and the raw YUV video file a.yuv
878
to MPEG file a.mpg.
879

    
880
* You can also do audio and video conversions at the same time:
881

    
882
@example
883
ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
884
@end example
885

    
886
Converts a.wav to MPEG audio at 22050 Hz sample rate.
887

    
888
* You can encode to several formats at the same time and define a
889
mapping from input stream to output streams:
890

    
891
@example
892
ffmpeg -i /tmp/a.wav -ab 64k /tmp/a.mp2 -ab 128k /tmp/b.mp2 -map 0:0 -map 0:0
893
@end example
894

    
895
Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
896
file:index' specifies which input stream is used for each output
897
stream, in the order of the definition of output streams.
898

    
899
* You can transcode decrypted VOBs:
900

    
901
@example
902
ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec libmp3lame -ab 128k snatch.avi
903
@end example
904

    
905
This is a typical DVD ripping example; the input is a VOB file, the
906
output an AVI file with MPEG-4 video and MP3 audio. Note that in this
907
command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
908
GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
909
input video. Furthermore, the audio stream is MP3-encoded so you need
910
to enable LAME support by passing @code{--enable-libmp3lame} to configure.
911
The mapping is particularly useful for DVD transcoding
912
to get the desired audio language.
913

    
914
NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
915

    
916
* You can extract images from a video, or create a video from many images:
917

    
918
For extracting images from a video:
919
@example
920
ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
921
@end example
922

    
923
This will extract one video frame per second from the video and will
924
output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
925
etc. Images will be rescaled to fit the new WxH values.
926

    
927
If you want to extract just a limited number of frames, you can use the
928
above command in combination with the -vframes or -t option, or in
929
combination with -ss to start extracting from a certain point in time.
930

    
931
For creating a video from many images:
932
@example
933
ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
934
@end example
935

    
936
The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
937
composed of three digits padded with zeroes to express the sequence
938
number. It is the same syntax supported by the C printf function, but
939
only formats accepting a normal integer are suitable.
940

    
941
* You can put many streams of the same type in the output:
942

    
943
@example
944
ffmpeg -i test1.avi -i test2.avi -vcodec copy -acodec copy -vcodec copy -acodec copy test12.avi -newvideo -newaudio
945
@end example
946

    
947
In addition to the first video and audio streams, the resulting
948
output file @file{test12.avi} will contain the second video
949
and the second audio stream found in the input streams list.
950

    
951
The @code{-newvideo}, @code{-newaudio} and @code{-newsubtitle}
952
options have to be specified immediately after the name of the output
953
file to which you want to add them.
954
@c man end EXAMPLES
955

    
956
@include indevs.texi
957
@include outdevs.texi
958
@include protocols.texi
959
@include filters.texi
960

    
961
@ignore
962

    
963
@setfilename ffmpeg
964
@settitle FFmpeg video converter
965

    
966
@c man begin SEEALSO
967
ffplay(1), ffprobe(1), ffserver(1) and the FFmpeg HTML documentation
968
@c man end
969

    
970
@c man begin AUTHORS
971
The FFmpeg developers
972
@c man end
973

    
974
@end ignore
975

    
976
@bye