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\input texinfo @c -*- texinfo -*-
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@settitle FFmpeg Documentation
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@titlepage
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@center @titlefont{FFmpeg Documentation}
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@end titlepage
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@top
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@contents
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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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@itemize
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@item
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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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@item
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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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@item
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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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@end itemize
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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).
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There is no default for input streams,
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for output streams it is set by default to the size of the source stream.
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If the input file has video streams with different resolutions, the behaviour is undefined.
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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 the video display aspect ratio specified by @var{aspect}.
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@var{aspect} can be a floating point number string, or a string of the
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form @var{num}:@var{den}, where @var{num} and @var{den} are the
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numerator and denominator of the aspect ratio. For example "4:3",
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"16:9", "1.3333", and "1.7777" are valid argument values.
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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 quantizer 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 (see section "Expression Evaluation")
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(default = @code{tex^qComp}).
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When computing the rate control equation expression, besides the
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standard functions defined in the section "Expression Evaluation", the
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following functions are available:
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@table @var
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@item bits2qp(bits)
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@item qp2bits(qp)
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@end table
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and the following constants are available:
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@table @var
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@item iTex
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@item pTex
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@item tex
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@item mv
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@item fCode
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@item iCount
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@item mcVar
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@item var
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@item isI
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@item isP
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@item isB
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@item avgQP
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@item qComp
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@item avgIITex
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@item avgPITex
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@item avgPPTex
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@item avgBPTex
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@item avgTex
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@end table
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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", "mjpeg2jpeg".
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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. For input streams it is set by
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default to 44100 Hz, for output streams it is set by default to the
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frequency of the input stream. If the input file has audio streams
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with different frequencies, the behaviour is undefined.
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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 -audio_service_type @var{type}
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Set the type of service that the audio stream contains.
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@table @option
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@item ma
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Main Audio Service (default)
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@item ef
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Effects
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@item vi
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Visually Impaired
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@item hi
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Hearing Impaired
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@item di
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Dialogue
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@item co
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Commentary
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@item em
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Emergency
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@item vo
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Voice Over
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@item ka
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Karaoke
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@end table
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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).
629
@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
638
ffmpeg -i file.mov -an -vn -sbsf mov2textsub -scodec copy -f rawvideo sub.txt
639
@end example
640
@end table
641

    
642
@section Audio/Video grab options
643

    
644
@table @option
645
@item -vc @var{channel}
646
Set video grab channel (DV1394 only).
647
@item -tvstd @var{standard}
648
Set television standard (NTSC, PAL (SECAM)).
649
@item -isync
650
Synchronize read on input.
651
@end table
652

    
653
@section Advanced options
654

    
655
@table @option
656
@item -map @var{input_file_id}.@var{input_stream_id}[:@var{sync_file_id}.@var{sync_stream_id}]
657

    
658
Designate an input stream as a source for the output file. Each input
659
stream is identified by the input file index @var{input_file_id} and
660
the input stream index @var{input_stream_id} within the input
661
file. Both indexes start at 0. If specified,
662
@var{sync_file_id}.@var{sync_stream_id} sets which input stream
663
is used as a presentation sync reference.
664

    
665
The @code{-map} options must be specified just after the output file.
666
If any @code{-map} options are used, the number of @code{-map} options
667
on the command line must match the number of streams in the output
668
file. The first @code{-map} option on the command line specifies the
669
source for output stream 0, the second @code{-map} option specifies
670
the source for output stream 1, etc.
671

    
672
For example, if you have two audio streams in the first input file,
673
these streams are identified by "0.0" and "0.1". You can use
674
@code{-map} to select which stream to place in an output file. For
675
example:
676
@example
677
ffmpeg -i INPUT out.wav -map 0.1
678
@end example
679
will map the input stream in @file{INPUT} identified by "0.1" to
680
the (single) output stream in @file{out.wav}.
681

    
682
For example, to select the stream with index 2 from input file
683
@file{a.mov} (specified by the identifier "0.2"), and stream with
684
index 6 from input @file{b.mov} (specified by the identifier "1.6"),
685
and copy them to the output file @file{out.mov}:
686
@example
687
ffmpeg -i a.mov -i b.mov -vcodec copy -acodec copy out.mov -map 0.2 -map 1.6
688
@end example
689

    
690
To add more streams to the output file, you can use the
691
@code{-newaudio}, @code{-newvideo}, @code{-newsubtitle} options.
692

    
693
@item -map_meta_data @var{outfile}[,@var{metadata}]:@var{infile}[,@var{metadata}]
694
Deprecated, use @var{-map_metadata} instead.
695

    
696
@item -map_metadata @var{outfile}[,@var{metadata}]:@var{infile}[,@var{metadata}]
697
Set metadata information of @var{outfile} from @var{infile}. Note that those
698
are file indices (zero-based), not filenames.
699
Optional @var{metadata} parameters specify, which metadata to copy - (g)lobal
700
(i.e. metadata that applies to the whole file), per-(s)tream, per-(c)hapter or
701
per-(p)rogram. All metadata specifiers other than global must be followed by the
702
stream/chapter/program number. If metadata specifier is omitted, it defaults to
703
global.
704

    
705
By default, global metadata is copied from the first input file to all output files,
706
per-stream and per-chapter metadata is copied along with streams/chapters. These
707
default mappings are disabled by creating any mapping of the relevant type. A negative
708
file index can be used to create a dummy mapping that just disables automatic copying.
709

    
710
For example to copy metadata from the first stream of the input file to global metadata
711
of the output file:
712
@example
713
ffmpeg -i in.ogg -map_metadata 0:0,s0 out.mp3
714
@end example
715
@item -map_chapters @var{outfile}:@var{infile}
716
Copy chapters from @var{infile} to @var{outfile}. If no chapter mapping is specified,
717
then chapters are copied from the first input file with at least one chapter to all
718
output files. Use a negative file index to disable any chapter copying.
719
@item -debug
720
Print specific debug info.
721
@item -benchmark
722
Show benchmarking information at the end of an encode.
723
Shows CPU time used and maximum memory consumption.
724
Maximum memory consumption is not supported on all systems,
725
it will usually display as 0 if not supported.
726
@item -dump
727
Dump each input packet.
728
@item -hex
729
When dumping packets, also dump the payload.
730
@item -bitexact
731
Only use bit exact algorithms (for codec testing).
732
@item -ps @var{size}
733
Set RTP payload size in bytes.
734
@item -re
735
Read input at native frame rate. Mainly used to simulate a grab device.
736
@item -loop_input
737
Loop over the input stream. Currently it works only for image
738
streams. This option is used for automatic FFserver testing.
739
@item -loop_output @var{number_of_times}
740
Repeatedly loop output for formats that support looping such as animated GIF
741
(0 will loop the output infinitely).
742
@item -threads @var{count}
743
Thread count.
744
@item -vsync @var{parameter}
745
Video sync method.
746

    
747
@table @option
748
@item 0
749
Each frame is passed with its timestamp from the demuxer to the muxer.
750
@item 1
751
Frames will be duplicated and dropped to achieve exactly the requested
752
constant framerate.
753
@item 2
754
Frames are passed through with their timestamp or dropped so as to
755
prevent 2 frames from having the same timestamp.
756
@item -1
757
Chooses between 1 and 2 depending on muxer capabilities. This is the
758
default method.
759
@end table
760

    
761
With -map you can select from which stream the timestamps should be
762
taken. You can leave either video or audio unchanged and sync the
763
remaining stream(s) to the unchanged one.
764

    
765
@item -async @var{samples_per_second}
766
Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
767
the parameter is the maximum samples per second by which the audio is changed.
768
-async 1 is a special case where only the start of the audio stream is corrected
769
without any later correction.
770
@item -copyts
771
Copy timestamps from input to output.
772
@item -copytb
773
Copy input stream time base from input to output when stream copying.
774
@item -shortest
775
Finish encoding when the shortest input stream ends.
776
@item -dts_delta_threshold
777
Timestamp discontinuity delta threshold.
778
@item -muxdelay @var{seconds}
779
Set the maximum demux-decode delay.
780
@item -muxpreload @var{seconds}
781
Set the initial demux-decode delay.
782
@item -streamid @var{output-stream-index}:@var{new-value}
783
Assign a new stream-id value to an output stream. This option should be
784
specified prior to the output filename to which it applies.
785
For the situation where multiple output files exist, a streamid
786
may be reassigned to a different value.
787

    
788
For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
789
an output mpegts file:
790
@example
791
ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
792
@end example
793
@end table
794

    
795
@section Preset files
796

    
797
A preset file contains a sequence of @var{option}=@var{value} pairs,
798
one for each line, specifying a sequence of options which would be
799
awkward to specify on the command line. Lines starting with the hash
800
('#') character are ignored and are used to provide comments. Check
801
the @file{ffpresets} directory in the FFmpeg source tree for examples.
802

    
803
Preset files are specified with the @code{vpre}, @code{apre},
804
@code{spre}, and @code{fpre} options. The @code{fpre} option takes the
805
filename of the preset instead of a preset name as input and can be
806
used for any kind of codec. For the @code{vpre}, @code{apre}, and
807
@code{spre} options, the options specified in a preset file are
808
applied to the currently selected codec of the same type as the preset
809
option.
810

    
811
The argument passed to the @code{vpre}, @code{apre}, and @code{spre}
812
preset options identifies the preset file to use according to the
813
following rules:
814

    
815
First ffmpeg searches for a file named @var{arg}.ffpreset in the
816
directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
817
the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg})
818
in that order. For example, if the argument is @code{libx264-max}, it will
819
search for the file @file{libx264-max.ffpreset}.
820

    
821
If no such file is found, then ffmpeg will search for a file named
822
@var{codec_name}-@var{arg}.ffpreset in the above-mentioned
823
directories, where @var{codec_name} is the name of the codec to which
824
the preset file options will be applied. For example, if you select
825
the video codec with @code{-vcodec libx264} and use @code{-vpre max},
826
then it will search for the file @file{libx264-max.ffpreset}.
827
@c man end
828

    
829
@chapter Tips
830
@c man begin TIPS
831

    
832
@itemize
833
@item
834
For streaming at very low bitrate application, use a low frame rate
835
and a small GOP size. This is especially true for RealVideo where
836
the Linux player does not seem to be very fast, so it can miss
837
frames. An example is:
838

    
839
@example
840
ffmpeg -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
841
@end example
842

    
843
@item
844
The parameter 'q' which is displayed while encoding is the current
845
quantizer. The value 1 indicates that a very good quality could
846
be achieved. The value 31 indicates the worst quality. If q=31 appears
847
too often, it means that the encoder cannot compress enough to meet
848
your bitrate. You must either increase the bitrate, decrease the
849
frame rate or decrease the frame size.
850

    
851
@item
852
If your computer is not fast enough, you can speed up the
853
compression at the expense of the compression ratio. You can use
854
'-me zero' to speed up motion estimation, and '-intra' to disable
855
motion estimation completely (you have only I-frames, which means it
856
is about as good as JPEG compression).
857

    
858
@item
859
To have very low audio bitrates, reduce the sampling frequency
860
(down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
861

    
862
@item
863
To have a constant quality (but a variable bitrate), use the option
864
'-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
865
quality).
866

    
867
@item
868
When converting video files, you can use the '-sameq' option which
869
uses the same quality factor in the encoder as in the decoder.
870
It allows almost lossless encoding.
871

    
872
@end itemize
873
@c man end TIPS
874

    
875
@chapter Examples
876
@c man begin EXAMPLES
877

    
878
@section Video and Audio grabbing
879

    
880
FFmpeg can grab video and audio from devices given that you specify the input
881
format and device.
882

    
883
@example
884
ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
885
@end example
886

    
887
Note that you must activate the right video source and channel before
888
launching FFmpeg with any TV viewer such as xawtv
889
(@url{http://linux.bytesex.org/xawtv/}) by Gerd Knorr. You also
890
have to set the audio recording levels correctly with a
891
standard mixer.
892

    
893
@section X11 grabbing
894

    
895
FFmpeg can grab the X11 display.
896

    
897
@example
898
ffmpeg -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
899
@end example
900

    
901
0.0 is display.screen number of your X11 server, same as
902
the DISPLAY environment variable.
903

    
904
@example
905
ffmpeg -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
906
@end example
907

    
908
0.0 is display.screen number of your X11 server, same as the DISPLAY environment
909
variable. 10 is the x-offset and 20 the y-offset for the grabbing.
910

    
911
@section Video and Audio file format conversion
912

    
913
FFmpeg can use any supported file format and protocol as input:
914

    
915
Examples:
916
@itemize
917
@item
918
You can use YUV files as input:
919

    
920
@example
921
ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
922
@end example
923

    
924
It will use the files:
925
@example
926
/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
927
/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
928
@end example
929

    
930
The Y files use twice the resolution of the U and V files. They are
931
raw files, without header. They can be generated by all decent video
932
decoders. You must specify the size of the image with the @option{-s} option
933
if FFmpeg cannot guess it.
934

    
935
@item
936
You can input from a raw YUV420P file:
937

    
938
@example
939
ffmpeg -i /tmp/test.yuv /tmp/out.avi
940
@end example
941

    
942
test.yuv is a file containing raw YUV planar data. Each frame is composed
943
of the Y plane followed by the U and V planes at half vertical and
944
horizontal resolution.
945

    
946
@item
947
You can output to a raw YUV420P file:
948

    
949
@example
950
ffmpeg -i mydivx.avi hugefile.yuv
951
@end example
952

    
953
@item
954
You can set several input files and output files:
955

    
956
@example
957
ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
958
@end example
959

    
960
Converts the audio file a.wav and the raw YUV video file a.yuv
961
to MPEG file a.mpg.
962

    
963
@item
964
You can also do audio and video conversions at the same time:
965

    
966
@example
967
ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
968
@end example
969

    
970
Converts a.wav to MPEG audio at 22050 Hz sample rate.
971

    
972
@item
973
You can encode to several formats at the same time and define a
974
mapping from input stream to output streams:
975

    
976
@example
977
ffmpeg -i /tmp/a.wav -ab 64k /tmp/a.mp2 -ab 128k /tmp/b.mp2 -map 0:0 -map 0:0
978
@end example
979

    
980
Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
981
file:index' specifies which input stream is used for each output
982
stream, in the order of the definition of output streams.
983

    
984
@item
985
You can transcode decrypted VOBs:
986

    
987
@example
988
ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec libmp3lame -ab 128k snatch.avi
989
@end example
990

    
991
This is a typical DVD ripping example; the input is a VOB file, the
992
output an AVI file with MPEG-4 video and MP3 audio. Note that in this
993
command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
994
GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
995
input video. Furthermore, the audio stream is MP3-encoded so you need
996
to enable LAME support by passing @code{--enable-libmp3lame} to configure.
997
The mapping is particularly useful for DVD transcoding
998
to get the desired audio language.
999

    
1000
NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
1001

    
1002
@item
1003
You can extract images from a video, or create a video from many images:
1004

    
1005
For extracting images from a video:
1006
@example
1007
ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
1008
@end example
1009

    
1010
This will extract one video frame per second from the video and will
1011
output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
1012
etc. Images will be rescaled to fit the new WxH values.
1013

    
1014
If you want to extract just a limited number of frames, you can use the
1015
above command in combination with the -vframes or -t option, or in
1016
combination with -ss to start extracting from a certain point in time.
1017

    
1018
For creating a video from many images:
1019
@example
1020
ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
1021
@end example
1022

    
1023
The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
1024
composed of three digits padded with zeroes to express the sequence
1025
number. It is the same syntax supported by the C printf function, but
1026
only formats accepting a normal integer are suitable.
1027

    
1028
@item
1029
You can put many streams of the same type in the output:
1030

    
1031
@example
1032
ffmpeg -i test1.avi -i test2.avi -vcodec copy -acodec copy -vcodec copy -acodec copy test12.avi -newvideo -newaudio
1033
@end example
1034

    
1035
In addition to the first video and audio streams, the resulting
1036
output file @file{test12.avi} will contain the second video
1037
and the second audio stream found in the input streams list.
1038

    
1039
The @code{-newvideo}, @code{-newaudio} and @code{-newsubtitle}
1040
options have to be specified immediately after the name of the output
1041
file to which you want to add them.
1042

    
1043
@end itemize
1044
@c man end EXAMPLES
1045

    
1046
@include eval.texi
1047
@include encoders.texi
1048
@include demuxers.texi
1049
@include muxers.texi
1050
@include indevs.texi
1051
@include outdevs.texi
1052
@include protocols.texi
1053
@include bitstream_filters.texi
1054
@include filters.texi
1055
@include metadata.texi
1056

    
1057
@ignore
1058

    
1059
@setfilename ffmpeg
1060
@settitle FFmpeg video converter
1061

    
1062
@c man begin SEEALSO
1063
ffplay(1), ffprobe(1), ffserver(1) and the FFmpeg HTML documentation
1064
@c man end
1065

    
1066
@c man begin AUTHORS
1067
The FFmpeg developers
1068
@c man end
1069

    
1070
@end ignore
1071

    
1072
@bye