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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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@item -force_key_frames @var{time}[,@var{time}...]
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Force key frames at the specified timestamps, more precisely at the first
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frames after each specified time.
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This option can be useful to ensure that a seek point is present at a
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chapter mark or any other designated place in the output file.
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The timestamps must be specified in ascending order.
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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{metadata}]:@var{infile}[,@var{metadata}]
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Set meta data information of @var{outfile} from @var{infile}. Note that those
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are file indices (zero-based), not filenames.
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Optional @var{metadata} parameters specify, which metadata to copy - (g)lobal
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(i.e. metadata that applies to the whole file), per-(s)tream, per-(c)hapter or
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per-(p)rogram. All metadata specifiers other than global must be followed by the
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stream/chapter/program number. If metadata specifier is omitted, it defaults to
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global.
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For example to copy metadata from the first stream of the input file to global metadata
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of the output file:
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@example
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ffmpeg -i in.ogg -map_meta_data 0:0,s0 out.mp3
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@end example
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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.
617
@item -re
618
Read input at native frame rate. Mainly used to simulate a grab device.
619
@item -loop_input
620
Loop over the input stream. Currently it works only for image
621
streams. This option is used for automatic FFserver testing.
622
@item -loop_output @var{number_of_times}
623
Repeatedly loop output for formats that support looping such as animated GIF
624
(0 will loop the output infinitely).
625
@item -threads @var{count}
626
Thread count.
627
@item -vsync @var{parameter}
628
Video sync method.
629
0   Each frame is passed with its timestamp from the demuxer to the muxer
630
1   Frames will be duplicated and dropped to achieve exactly the requested
631
    constant framerate.
632
2   Frames are passed through with their timestamp or dropped so as to prevent
633
    2 frames from having the same timestamp
634
-1  Chooses between 1 and 2 depending on muxer capabilities. This is the default method.
635

    
636
With -map you can select from
637
which stream the timestamps should be taken. You can leave either video or
638
audio unchanged and sync the remaining stream(s) to the unchanged one.
639
@item -async @var{samples_per_second}
640
Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
641
the parameter is the maximum samples per second by which the audio is changed.
642
-async 1 is a special case where only the start of the audio stream is corrected
643
without any later correction.
644
@item -copyts
645
Copy timestamps from input to output.
646
@item -shortest
647
Finish encoding when the shortest input stream ends.
648
@item -dts_delta_threshold
649
Timestamp discontinuity delta threshold.
650
@item -muxdelay @var{seconds}
651
Set the maximum demux-decode delay.
652
@item -muxpreload @var{seconds}
653
Set the initial demux-decode delay.
654
@item -streamid @var{output-stream-index}:@var{new-value}
655
Assign a new value to a stream's stream-id field in the next output file.
656
All stream-id fields are reset to default for each output file.
657

    
658
For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
659
an output mpegts file:
660
@example
661
ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
662
@end example
663
@end table
664

    
665
@section Preset files
666

    
667
A preset file contains a sequence of @var{option}=@var{value} pairs,
668
one for each line, specifying a sequence of options which would be
669
awkward to specify on the command line. Lines starting with the hash
670
('#') character are ignored and are used to provide comments. Check
671
the @file{ffpresets} directory in the FFmpeg source tree for examples.
672

    
673
Preset files are specified with the @code{vpre}, @code{apre},
674
@code{spre}, and @code{fpre} options. The @code{fpre} option takes the
675
filename of the preset instead of a preset name as input and can be
676
used for any kind of codec. For the @code{vpre}, @code{apre}, and
677
@code{spre} options, the options specified in a preset file are
678
applied to the currently selected codec of the same type as the preset
679
option.
680

    
681
The argument passed to the @code{vpre}, @code{apre}, and @code{spre}
682
preset options identifies the preset file to use according to the
683
following rules:
684

    
685
First ffmpeg searches for a file named @var{arg}.ffpreset in the
686
directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
687
the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg})
688
in that order. For example, if the argument is @code{libx264-max}, it will
689
search for the file @file{libx264-max.ffpreset}.
690

    
691
If no such file is found, then ffmpeg will search for a file named
692
@var{codec_name}-@var{arg}.ffpreset in the above-mentioned
693
directories, where @var{codec_name} is the name of the codec to which
694
the preset file options will be applied. For example, if you select
695
the video codec with @code{-vcodec libx264} and use @code{-vpre max},
696
then it will search for the file @file{libx264-max.ffpreset}.
697

    
698
@anchor{FFmpeg formula evaluator}
699
@section FFmpeg formula evaluator
700

    
701
When evaluating a rate control string, FFmpeg uses an internal formula
702
evaluator.
703

    
704
The following binary operators are available: @code{+}, @code{-},
705
@code{*}, @code{/}, @code{^}.
706

    
707
The following unary operators are available: @code{+}, @code{-},
708
@code{(...)}.
709

    
710
The following statements are available: @code{ld}, @code{st},
711
@code{while}.
712

    
713
The following functions are available:
714
@table @var
715
@item sinh(x)
716
@item cosh(x)
717
@item tanh(x)
718
@item sin(x)
719
@item cos(x)
720
@item tan(x)
721
@item atan(x)
722
@item asin(x)
723
@item acos(x)
724
@item exp(x)
725
@item log(x)
726
@item abs(x)
727
@item squish(x)
728
@item gauss(x)
729
@item mod(x, y)
730
@item max(x, y)
731
@item min(x, y)
732
@item eq(x, y)
733
@item gte(x, y)
734
@item gt(x, y)
735
@item lte(x, y)
736
@item lt(x, y)
737
@item bits2qp(bits)
738
@item qp2bits(qp)
739
@end table
740

    
741
The following constants are available:
742
@table @var
743
@item PI
744
@item E
745
@item iTex
746
@item pTex
747
@item tex
748
@item mv
749
@item fCode
750
@item iCount
751
@item mcVar
752
@item var
753
@item isI
754
@item isP
755
@item isB
756
@item avgQP
757
@item qComp
758
@item avgIITex
759
@item avgPITex
760
@item avgPPTex
761
@item avgBPTex
762
@item avgTex
763
@end table
764

    
765
@c man end
766

    
767
@chapter Tips
768
@c man begin TIPS
769

    
770
@itemize
771
@item
772
For streaming at very low bitrate application, use a low frame rate
773
and a small GOP size. This is especially true for RealVideo where
774
the Linux player does not seem to be very fast, so it can miss
775
frames. An example is:
776

    
777
@example
778
ffmpeg -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
779
@end example
780

    
781
@item
782
The parameter 'q' which is displayed while encoding is the current
783
quantizer. The value 1 indicates that a very good quality could
784
be achieved. The value 31 indicates the worst quality. If q=31 appears
785
too often, it means that the encoder cannot compress enough to meet
786
your bitrate. You must either increase the bitrate, decrease the
787
frame rate or decrease the frame size.
788

    
789
@item
790
If your computer is not fast enough, you can speed up the
791
compression at the expense of the compression ratio. You can use
792
'-me zero' to speed up motion estimation, and '-intra' to disable
793
motion estimation completely (you have only I-frames, which means it
794
is about as good as JPEG compression).
795

    
796
@item
797
To have very low audio bitrates, reduce the sampling frequency
798
(down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
799

    
800
@item
801
To have a constant quality (but a variable bitrate), use the option
802
'-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
803
quality).
804

    
805
@item
806
When converting video files, you can use the '-sameq' option which
807
uses the same quality factor in the encoder as in the decoder.
808
It allows almost lossless encoding.
809

    
810
@end itemize
811
@c man end TIPS
812

    
813
@chapter Examples
814
@c man begin EXAMPLES
815

    
816
@section Video and Audio grabbing
817

    
818
FFmpeg can grab video and audio from devices given that you specify the input
819
format and device.
820

    
821
@example
822
ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
823
@end example
824

    
825
Note that you must activate the right video source and channel before
826
launching FFmpeg with any TV viewer such as xawtv
827
(@url{http://linux.bytesex.org/xawtv/}) by Gerd Knorr. You also
828
have to set the audio recording levels correctly with a
829
standard mixer.
830

    
831
@section X11 grabbing
832

    
833
FFmpeg can grab the X11 display.
834

    
835
@example
836
ffmpeg -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
837
@end example
838

    
839
0.0 is display.screen number of your X11 server, same as
840
the DISPLAY environment variable.
841

    
842
@example
843
ffmpeg -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
844
@end example
845

    
846
0.0 is display.screen number of your X11 server, same as the DISPLAY environment
847
variable. 10 is the x-offset and 20 the y-offset for the grabbing.
848

    
849
@section Video and Audio file format conversion
850

    
851
* FFmpeg can use any supported file format and protocol as input:
852

    
853
Examples:
854

    
855
* You can use YUV files as input:
856

    
857
@example
858
ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
859
@end example
860

    
861
It will use the files:
862
@example
863
/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
864
/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
865
@end example
866

    
867
The Y files use twice the resolution of the U and V files. They are
868
raw files, without header. They can be generated by all decent video
869
decoders. You must specify the size of the image with the @option{-s} option
870
if FFmpeg cannot guess it.
871

    
872
* You can input from a raw YUV420P file:
873

    
874
@example
875
ffmpeg -i /tmp/test.yuv /tmp/out.avi
876
@end example
877

    
878
test.yuv is a file containing raw YUV planar data. Each frame is composed
879
of the Y plane followed by the U and V planes at half vertical and
880
horizontal resolution.
881

    
882
* You can output to a raw YUV420P file:
883

    
884
@example
885
ffmpeg -i mydivx.avi hugefile.yuv
886
@end example
887

    
888
* You can set several input files and output files:
889

    
890
@example
891
ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
892
@end example
893

    
894
Converts the audio file a.wav and the raw YUV video file a.yuv
895
to MPEG file a.mpg.
896

    
897
* You can also do audio and video conversions at the same time:
898

    
899
@example
900
ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
901
@end example
902

    
903
Converts a.wav to MPEG audio at 22050 Hz sample rate.
904

    
905
* You can encode to several formats at the same time and define a
906
mapping from input stream to output streams:
907

    
908
@example
909
ffmpeg -i /tmp/a.wav -ab 64k /tmp/a.mp2 -ab 128k /tmp/b.mp2 -map 0:0 -map 0:0
910
@end example
911

    
912
Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
913
file:index' specifies which input stream is used for each output
914
stream, in the order of the definition of output streams.
915

    
916
* You can transcode decrypted VOBs:
917

    
918
@example
919
ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec libmp3lame -ab 128k snatch.avi
920
@end example
921

    
922
This is a typical DVD ripping example; the input is a VOB file, the
923
output an AVI file with MPEG-4 video and MP3 audio. Note that in this
924
command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
925
GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
926
input video. Furthermore, the audio stream is MP3-encoded so you need
927
to enable LAME support by passing @code{--enable-libmp3lame} to configure.
928
The mapping is particularly useful for DVD transcoding
929
to get the desired audio language.
930

    
931
NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
932

    
933
* You can extract images from a video, or create a video from many images:
934

    
935
For extracting images from a video:
936
@example
937
ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
938
@end example
939

    
940
This will extract one video frame per second from the video and will
941
output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
942
etc. Images will be rescaled to fit the new WxH values.
943

    
944
If you want to extract just a limited number of frames, you can use the
945
above command in combination with the -vframes or -t option, or in
946
combination with -ss to start extracting from a certain point in time.
947

    
948
For creating a video from many images:
949
@example
950
ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
951
@end example
952

    
953
The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
954
composed of three digits padded with zeroes to express the sequence
955
number. It is the same syntax supported by the C printf function, but
956
only formats accepting a normal integer are suitable.
957

    
958
* You can put many streams of the same type in the output:
959

    
960
@example
961
ffmpeg -i test1.avi -i test2.avi -vcodec copy -acodec copy -vcodec copy -acodec copy test12.avi -newvideo -newaudio
962
@end example
963

    
964
In addition to the first video and audio streams, the resulting
965
output file @file{test12.avi} will contain the second video
966
and the second audio stream found in the input streams list.
967

    
968
The @code{-newvideo}, @code{-newaudio} and @code{-newsubtitle}
969
options have to be specified immediately after the name of the output
970
file to which you want to add them.
971
@c man end EXAMPLES
972

    
973
@include indevs.texi
974
@include outdevs.texi
975
@include protocols.texi
976
@include filters.texi
977

    
978
@ignore
979

    
980
@setfilename ffmpeg
981
@settitle FFmpeg video converter
982

    
983
@c man begin SEEALSO
984
ffplay(1), ffprobe(1), ffserver(1) and the FFmpeg HTML documentation
985
@c man end
986

    
987
@c man begin AUTHORS
988
The FFmpeg developers
989
@c man end
990

    
991
@end ignore
992

    
993
@bye