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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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@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, 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 (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 -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}]
629
Set meta data information of @var{outfile} from @var{infile}. Note that those
630
are file indices (zero-based), not filenames.
631
Optional @var{metadata} parameters specify, which metadata to copy - (g)lobal
632
(i.e. metadata that applies to the whole file), per-(s)tream, per-(c)hapter or
633
per-(p)rogram. All metadata specifiers other than global must be followed by the
634
stream/chapter/program number. If metadata specifier is omitted, it defaults to
635
global.
636

    
637
By default, global metadata is copied from the first input file to all output files,
638
per-stream and per-chapter metadata is copied along with streams/chapters. These
639
default mappings are disabled by creating any mapping of the relevant type. A negative
640
file index can be used to create a dummy mapping that just disables automatic copying.
641

    
642
For example to copy metadata from the first stream of the input file to global metadata
643
of the output file:
644
@example
645
ffmpeg -i in.ogg -map_meta_data 0:0,s0 out.mp3
646
@end example
647
@item -map_chapters @var{outfile}:@var{infile}
648
Copy chapters from @var{infile} to @var{outfile}. If no chapter mapping is specified,
649
then chapters are copied from the first input file with at least one chapter to all
650
output files. Use a negative file index to disable any chapter copying.
651
@item -debug
652
Print specific debug info.
653
@item -benchmark
654
Show benchmarking information at the end of an encode.
655
Shows CPU time used and maximum memory consumption.
656
Maximum memory consumption is not supported on all systems,
657
it will usually display as 0 if not supported.
658
@item -dump
659
Dump each input packet.
660
@item -hex
661
When dumping packets, also dump the payload.
662
@item -bitexact
663
Only use bit exact algorithms (for codec testing).
664
@item -ps @var{size}
665
Set RTP payload size in bytes.
666
@item -re
667
Read input at native frame rate. Mainly used to simulate a grab device.
668
@item -loop_input
669
Loop over the input stream. Currently it works only for image
670
streams. This option is used for automatic FFserver testing.
671
@item -loop_output @var{number_of_times}
672
Repeatedly loop output for formats that support looping such as animated GIF
673
(0 will loop the output infinitely).
674
@item -threads @var{count}
675
Thread count.
676
@item -vsync @var{parameter}
677
Video sync method.
678

    
679
@table @option
680
@item 0
681
Each frame is passed with its timestamp from the demuxer to the muxer.
682
@item 1
683
Frames will be duplicated and dropped to achieve exactly the requested
684
constant framerate.
685
@item 2
686
Frames are passed through with their timestamp or dropped so as to
687
prevent 2 frames from having the same timestamp.
688
@item -1
689
Chooses between 1 and 2 depending on muxer capabilities. This is the
690
default method.
691
@end table
692

    
693
With -map you can select from which stream the timestamps should be
694
taken. You can leave either video or audio unchanged and sync the
695
remaining stream(s) to the unchanged one.
696

    
697
@item -async @var{samples_per_second}
698
Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
699
the parameter is the maximum samples per second by which the audio is changed.
700
-async 1 is a special case where only the start of the audio stream is corrected
701
without any later correction.
702
@item -copyts
703
Copy timestamps from input to output.
704
@item -copytb
705
Copy input stream time base from input to output when stream copying.
706
@item -shortest
707
Finish encoding when the shortest input stream ends.
708
@item -dts_delta_threshold
709
Timestamp discontinuity delta threshold.
710
@item -muxdelay @var{seconds}
711
Set the maximum demux-decode delay.
712
@item -muxpreload @var{seconds}
713
Set the initial demux-decode delay.
714
@item -streamid @var{output-stream-index}:@var{new-value}
715
Assign a new stream-id value to an output stream. This option should be
716
specified prior to the output filename to which it applies.
717
For the situation where multiple output files exist, a streamid
718
may be reassigned to a different value.
719

    
720
For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
721
an output mpegts file:
722
@example
723
ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
724
@end example
725
@end table
726

    
727
@section Preset files
728

    
729
A preset file contains a sequence of @var{option}=@var{value} pairs,
730
one for each line, specifying a sequence of options which would be
731
awkward to specify on the command line. Lines starting with the hash
732
('#') character are ignored and are used to provide comments. Check
733
the @file{ffpresets} directory in the FFmpeg source tree for examples.
734

    
735
Preset files are specified with the @code{vpre}, @code{apre},
736
@code{spre}, and @code{fpre} options. The @code{fpre} option takes the
737
filename of the preset instead of a preset name as input and can be
738
used for any kind of codec. For the @code{vpre}, @code{apre}, and
739
@code{spre} options, the options specified in a preset file are
740
applied to the currently selected codec of the same type as the preset
741
option.
742

    
743
The argument passed to the @code{vpre}, @code{apre}, and @code{spre}
744
preset options identifies the preset file to use according to the
745
following rules:
746

    
747
First ffmpeg searches for a file named @var{arg}.ffpreset in the
748
directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
749
the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg})
750
in that order. For example, if the argument is @code{libx264-max}, it will
751
search for the file @file{libx264-max.ffpreset}.
752

    
753
If no such file is found, then ffmpeg will search for a file named
754
@var{codec_name}-@var{arg}.ffpreset in the above-mentioned
755
directories, where @var{codec_name} is the name of the codec to which
756
the preset file options will be applied. For example, if you select
757
the video codec with @code{-vcodec libx264} and use @code{-vpre max},
758
then it will search for the file @file{libx264-max.ffpreset}.
759
@c man end
760

    
761
@chapter Tips
762
@c man begin TIPS
763

    
764
@itemize
765
@item
766
For streaming at very low bitrate application, use a low frame rate
767
and a small GOP size. This is especially true for RealVideo where
768
the Linux player does not seem to be very fast, so it can miss
769
frames. An example is:
770

    
771
@example
772
ffmpeg -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
773
@end example
774

    
775
@item
776
The parameter 'q' which is displayed while encoding is the current
777
quantizer. The value 1 indicates that a very good quality could
778
be achieved. The value 31 indicates the worst quality. If q=31 appears
779
too often, it means that the encoder cannot compress enough to meet
780
your bitrate. You must either increase the bitrate, decrease the
781
frame rate or decrease the frame size.
782

    
783
@item
784
If your computer is not fast enough, you can speed up the
785
compression at the expense of the compression ratio. You can use
786
'-me zero' to speed up motion estimation, and '-intra' to disable
787
motion estimation completely (you have only I-frames, which means it
788
is about as good as JPEG compression).
789

    
790
@item
791
To have very low audio bitrates, reduce the sampling frequency
792
(down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
793

    
794
@item
795
To have a constant quality (but a variable bitrate), use the option
796
'-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
797
quality).
798

    
799
@item
800
When converting video files, you can use the '-sameq' option which
801
uses the same quality factor in the encoder as in the decoder.
802
It allows almost lossless encoding.
803

    
804
@end itemize
805
@c man end TIPS
806

    
807
@chapter Examples
808
@c man begin EXAMPLES
809

    
810
@section Video and Audio grabbing
811

    
812
FFmpeg can grab video and audio from devices given that you specify the input
813
format and device.
814

    
815
@example
816
ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
817
@end example
818

    
819
Note that you must activate the right video source and channel before
820
launching FFmpeg with any TV viewer such as xawtv
821
(@url{http://linux.bytesex.org/xawtv/}) by Gerd Knorr. You also
822
have to set the audio recording levels correctly with a
823
standard mixer.
824

    
825
@section X11 grabbing
826

    
827
FFmpeg can grab the X11 display.
828

    
829
@example
830
ffmpeg -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
831
@end example
832

    
833
0.0 is display.screen number of your X11 server, same as
834
the DISPLAY environment variable.
835

    
836
@example
837
ffmpeg -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
838
@end example
839

    
840
0.0 is display.screen number of your X11 server, same as the DISPLAY environment
841
variable. 10 is the x-offset and 20 the y-offset for the grabbing.
842

    
843
@section Video and Audio file format conversion
844

    
845
FFmpeg can use any supported file format and protocol as input:
846

    
847
Examples:
848
@itemize
849
@item
850
You can use YUV files as input:
851

    
852
@example
853
ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
854
@end example
855

    
856
It will use the files:
857
@example
858
/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
859
/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
860
@end example
861

    
862
The Y files use twice the resolution of the U and V files. They are
863
raw files, without header. They can be generated by all decent video
864
decoders. You must specify the size of the image with the @option{-s} option
865
if FFmpeg cannot guess it.
866

    
867
@item
868
You can input from a raw YUV420P file:
869

    
870
@example
871
ffmpeg -i /tmp/test.yuv /tmp/out.avi
872
@end example
873

    
874
test.yuv is a file containing raw YUV planar data. Each frame is composed
875
of the Y plane followed by the U and V planes at half vertical and
876
horizontal resolution.
877

    
878
@item
879
You can output to a raw YUV420P file:
880

    
881
@example
882
ffmpeg -i mydivx.avi hugefile.yuv
883
@end example
884

    
885
@item
886
You can set several input files and output files:
887

    
888
@example
889
ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
890
@end example
891

    
892
Converts the audio file a.wav and the raw YUV video file a.yuv
893
to MPEG file a.mpg.
894

    
895
@item
896
You can also do audio and video conversions at the same time:
897

    
898
@example
899
ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
900
@end example
901

    
902
Converts a.wav to MPEG audio at 22050 Hz sample rate.
903

    
904
@item
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
@item
917
You can transcode decrypted VOBs:
918

    
919
@example
920
ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec libmp3lame -ab 128k snatch.avi
921
@end example
922

    
923
This is a typical DVD ripping example; the input is a VOB file, the
924
output an AVI file with MPEG-4 video and MP3 audio. Note that in this
925
command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
926
GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
927
input video. Furthermore, the audio stream is MP3-encoded so you need
928
to enable LAME support by passing @code{--enable-libmp3lame} to configure.
929
The mapping is particularly useful for DVD transcoding
930
to get the desired audio language.
931

    
932
NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
933

    
934
@item
935
You can extract images from a video, or create a video from many images:
936

    
937
For extracting images from a video:
938
@example
939
ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
940
@end example
941

    
942
This will extract one video frame per second from the video and will
943
output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
944
etc. Images will be rescaled to fit the new WxH values.
945

    
946
If you want to extract just a limited number of frames, you can use the
947
above command in combination with the -vframes or -t option, or in
948
combination with -ss to start extracting from a certain point in time.
949

    
950
For creating a video from many images:
951
@example
952
ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
953
@end example
954

    
955
The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
956
composed of three digits padded with zeroes to express the sequence
957
number. It is the same syntax supported by the C printf function, but
958
only formats accepting a normal integer are suitable.
959

    
960
@item
961
You can put many streams of the same type in the output:
962

    
963
@example
964
ffmpeg -i test1.avi -i test2.avi -vcodec copy -acodec copy -vcodec copy -acodec copy test12.avi -newvideo -newaudio
965
@end example
966

    
967
In addition to the first video and audio streams, the resulting
968
output file @file{test12.avi} will contain the second video
969
and the second audio stream found in the input streams list.
970

    
971
The @code{-newvideo}, @code{-newaudio} and @code{-newsubtitle}
972
options have to be specified immediately after the name of the output
973
file to which you want to add them.
974

    
975
@end itemize
976
@c man end EXAMPLES
977

    
978
@include eval.texi
979
@include demuxers.texi
980
@include muxers.texi
981
@include indevs.texi
982
@include outdevs.texi
983
@include protocols.texi
984
@include bitstream_filters.texi
985
@include filters.texi
986
@include metadata.texi
987

    
988
@ignore
989

    
990
@setfilename ffmpeg
991
@settitle FFmpeg video converter
992

    
993
@c man begin SEEALSO
994
ffplay(1), ffprobe(1), ffserver(1) and the FFmpeg HTML documentation
995
@c man end
996

    
997
@c man begin AUTHORS
998
The FFmpeg developers
999
@c man end
1000

    
1001
@end ignore
1002

    
1003
@bye