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\input texinfo @c -*- texinfo -*-
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@settitle FFmpeg Documentation
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@titlepage
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@sp 7
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@center @titlefont{FFmpeg Documentation}
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@sp 3
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@end titlepage
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@chapter Synopsis
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The generic syntax is:
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@example
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@c man begin SYNOPSIS
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ffmpeg [[infile options][@option{-i} @var{infile}]]... @{[outfile options] @var{outfile}@}...
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@c man end
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@end example
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@chapter Description
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@c man begin DESCRIPTION
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FFmpeg is a very fast video and audio converter. It can also grab from
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a live audio/video source.
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The command line interface is designed to be intuitive, in the sense
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that FFmpeg tries to figure out all parameters that can possibly be
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derived automatically. You usually only have to specify the target
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bitrate you want.
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FFmpeg can also convert from any sample rate to any other, and resize
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video on the fly with a high quality polyphase filter.
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As a general rule, options are applied to the next specified
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file. Therefore, order is important, and you can have the same
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option on the command line multiple times. Each occurrence is
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then applied to the next input or output file.
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* To set the video bitrate of the output file to 64kbit/s:
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@example
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ffmpeg -i input.avi -b 64k output.avi
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@end example
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* To force the frame rate of the output file to 24 fps:
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@example
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ffmpeg -i input.avi -r 24 output.avi
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@end example
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* To force the frame rate of the input file (valid for raw formats only)
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to 1 fps and the frame rate of the output file to 24 fps:
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@example
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ffmpeg -r 1 -i input.m2v -r 24 output.avi
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@end example
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The format option may be needed for raw input files.
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By default, FFmpeg tries to convert as losslessly as possible: It
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uses the same audio and video parameters for the outputs as the one
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specified for the inputs.
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@c man end DESCRIPTION
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@chapter Options
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@c man begin OPTIONS
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@include fftools-common-opts.texi
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@section Main options
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@table @option
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@item -f @var{fmt}
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Force format.
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@item -i @var{filename}
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input file name
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@item -y
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Overwrite output files.
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@item -t @var{duration}
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Restrict the transcoded/captured video sequence
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to the duration specified in seconds.
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@code{hh:mm:ss[.xxx]} syntax is also supported.
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@item -fs @var{limit_size}
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Set the file size limit.
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@item -ss @var{position}
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Seek to given time position in seconds.
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@code{hh:mm:ss[.xxx]} syntax is also supported.
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@item -itsoffset @var{offset}
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Set the input time offset in seconds.
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@code{[-]hh:mm:ss[.xxx]} syntax is also supported.
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This option affects all the input files that follow it.
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The offset is added to the timestamps of the input files.
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Specifying a positive offset means that the corresponding
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streams are delayed by 'offset' seconds.
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@item -timestamp @var{time}
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Set the recording timestamp in the container.
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The syntax for @var{time} is:
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@example
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now|([(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH[:MM[:SS[.m...]]])|(HH[MM[SS[.m...]]]))[Z|z])
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@end example
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If the value is "now" it takes the current time.
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Time is local time unless 'Z' or 'z' is appended, in which case it is
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interpreted as UTC.
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If the year-month-day part is not specified it takes the current
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year-month-day.
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@item -metadata @var{key}=@var{value}
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Set a metadata key/value pair.
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For example, for setting the title in the output file:
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@example
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ffmpeg -i in.avi -metadata title="my title" out.flv
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@end example
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@item -v @var{number}
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Set the logging verbosity level.
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@item -target @var{type}
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Specify target file type ("vcd", "svcd", "dvd", "dv", "dv50", "pal-vcd",
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"ntsc-svcd", ... ). All the format options (bitrate, codecs,
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buffer sizes) are then set automatically. You can just type:
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@example
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ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
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@end example
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Nevertheless you can specify additional options as long as you know
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they do not conflict with the standard, as in:
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@example
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ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
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@end example
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@item -dframes @var{number}
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Set the number of data frames to record.
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@item -scodec @var{codec}
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Force subtitle codec ('copy' to copy stream).
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@item -newsubtitle
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Add a new subtitle stream to the current output stream.
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@item -slang @var{code}
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Set the ISO 639 language code (3 letters) of the current subtitle stream.
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@end table
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@section Video Options
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@table @option
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@item -b @var{bitrate}
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Set the video bitrate in bit/s (default = 200 kb/s).
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@item -vframes @var{number}
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Set the number of video frames to record.
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@item -r @var{fps}
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Set frame rate (Hz value, fraction or abbreviation), (default = 25).
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@item -s @var{size}
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Set frame size. The format is @samp{wxh} (ffserver default = 160x128, ffmpeg default = same as source).
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The following abbreviations are recognized:
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@table @samp
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@item sqcif
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128x96
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@item qcif
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176x144
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@item cif
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352x288
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@item 4cif
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704x576
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@item 16cif
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1408x1152
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@item qqvga
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160x120
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@item qvga
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320x240
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@item vga
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640x480
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@item svga
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800x600
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@item xga
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1024x768
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@item uxga
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1600x1200
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@item qxga
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2048x1536
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@item sxga
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1280x1024
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@item qsxga
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2560x2048
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@item hsxga
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5120x4096
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@item wvga
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852x480
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@item wxga
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1366x768
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@item wsxga
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1600x1024
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@item wuxga
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1920x1200
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@item woxga
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2560x1600
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@item wqsxga
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3200x2048
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@item wquxga
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3840x2400
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@item whsxga
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6400x4096
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@item whuxga
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7680x4800
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@item cga
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320x200
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@item ega
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640x350
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@item hd480
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852x480
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@item hd720
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1280x720
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@item hd1080
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1920x1080
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@end table
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@item -aspect @var{aspect}
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Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).
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@item -croptop @var{size}
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@item -cropbottom @var{size}
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@item -cropleft @var{size}
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@item -cropright @var{size}
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All the crop options have been removed. Use -vf
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crop=width:height:x:y instead.
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@item -padtop @var{size}
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@item -padbottom @var{size}
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@item -padleft @var{size}
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@item -padright @var{size}
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@item -padcolor @var{hex_color}
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All the pad options have been removed. Use -vf
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pad=width:height:x:y:color instead.
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@item -vn
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Disable video recording.
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@item -bt @var{tolerance}
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Set video bitrate tolerance (in bits, default 4000k).
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Has a minimum value of: (target_bitrate/target_framerate).
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In 1-pass mode, bitrate tolerance specifies how far ratecontrol is
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willing to deviate from the target average bitrate value. This is
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not related to min/max bitrate. Lowering tolerance too much has
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an adverse effect on quality.
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@item -maxrate @var{bitrate}
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Set max video bitrate (in bit/s).
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Requires -bufsize to be set.
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@item -minrate @var{bitrate}
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Set min video bitrate (in bit/s).
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Most useful in setting up a CBR encode:
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@example
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ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
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@end example
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It is of little use elsewise.
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@item -bufsize @var{size}
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Set video buffer verifier buffer size (in bits).
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@item -vcodec @var{codec}
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Force video codec to @var{codec}. Use the @code{copy} special value to
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tell that the raw codec data must be copied as is.
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@item -sameq
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Use same video quality as source (implies VBR).
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@item -pass @var{n}
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Select the pass number (1 or 2). It is used to do two-pass
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video encoding. The statistics of the video are recorded in the first
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pass into a log file (see also the option -passlogfile),
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and in the second pass that log file is used to generate the video
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at the exact requested bitrate.
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On pass 1, you may just deactivate audio and set output to null,
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examples for Windows and Unix:
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@example
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ffmpeg -i foo.mov -vcodec libxvid -pass 1 -an -f rawvideo -y NUL
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ffmpeg -i foo.mov -vcodec libxvid -pass 1 -an -f rawvideo -y /dev/null
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@end example
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@item -passlogfile @var{prefix}
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Set two-pass log file name prefix to @var{prefix}, the default file name
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prefix is ``ffmpeg2pass''. The complete file name will be
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@file{PREFIX-N.log}, where N is a number specific to the output
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stream.
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@item -newvideo
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Add a new video stream to the current output stream.
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@item -vlang @var{code}
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Set the ISO 639 language code (3 letters) of the current video stream.
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@item -vf @var{filter_graph}
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@var{filter_graph} is a description of the filter graph to apply to
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the input video.
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Use the option "-filters" to show all the available filters (including
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also sources and sinks).
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@end table
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@section Advanced Video Options
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@table @option
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@item -pix_fmt @var{format}
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Set pixel format. Use 'list' as parameter to show all the supported
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pixel formats.
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@item -sws_flags @var{flags}
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Set SwScaler flags.
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@item -g @var{gop_size}
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Set the group of pictures size.
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@item -intra
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Use only intra frames.
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@item -vdt @var{n}
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Discard threshold.
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@item -qscale @var{q}
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Use fixed video quantizer scale (VBR).
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@item -qmin @var{q}
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minimum video quantizer scale (VBR)
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@item -qmax @var{q}
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maximum video quantizer scale (VBR)
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@item -qdiff @var{q}
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maximum difference between the quantizer scales (VBR)
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@item -qblur @var{blur}
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video quantizer scale blur (VBR) (range 0.0 - 1.0)
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@item -qcomp @var{compression}
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video quantizer scale compression (VBR) (default 0.5).
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Constant of ratecontrol equation. Recommended range for default rc_eq: 0.0-1.0
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@item -lmin @var{lambda}
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minimum video lagrange factor (VBR)
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@item -lmax @var{lambda}
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max video lagrange factor (VBR)
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@item -mblmin @var{lambda}
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minimum macroblock quantizer scale (VBR)
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@item -mblmax @var{lambda}
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maximum macroblock quantizer scale (VBR)
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These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
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but you may use the QP2LAMBDA constant to easily convert from 'q' units:
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@example
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ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
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@end example
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@item -rc_init_cplx @var{complexity}
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initial complexity for single pass encoding
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@item -b_qfactor @var{factor}
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qp factor between P- and B-frames
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@item -i_qfactor @var{factor}
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qp factor between P- and I-frames
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@item -b_qoffset @var{offset}
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qp offset between P- and B-frames
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@item -i_qoffset @var{offset}
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qp offset between P- and I-frames
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@item -rc_eq @var{equation}
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Set rate control equation (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".
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@example
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ffmpeg -i h264.mp4 -vcodec copy -vbsf h264_mp4toannexb -an out.h264
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@end example
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@item -force_key_frames @var{time}[,@var{time}...]
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Force key frames at the specified timestamps, more precisely at the first
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frames after each specified time.
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This option can be useful to ensure that a seek point is present at a
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chapter mark or any other designated place in the output file.
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The timestamps must be specified in ascending order.
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@end table
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@section Audio Options
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@table @option
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@item -aframes @var{number}
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Set the number of audio frames to record.
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@item -ar @var{freq}
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Set the audio sampling frequency (default = 44100 Hz).
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@item -ab @var{bitrate}
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Set the audio bitrate in bit/s (default = 64k).
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@item -aq @var{q}
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Set the audio quality (codec-specific, VBR).
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@item -ac @var{channels}
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Set the number of audio channels. For input streams it is set by
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default to 1, for output streams it is set by default to the same
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number of audio channels in input. If the input file has audio streams
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with different channel count, the behaviour is undefined.
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@item -an
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Disable audio recording.
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@item -acodec @var{codec}
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Force audio codec to @var{codec}. Use the @code{copy} special value to
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specify that the raw codec data must be copied as is.
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@item -newaudio
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Add a new audio track to the output file. If you want to specify parameters,
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do so before @code{-newaudio} (@code{-acodec}, @code{-ab}, etc..).
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Mapping will be done automatically, if the number of output streams is equal to
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the number of input streams, else it will pick the first one that matches. You
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can override the mapping using @code{-map} as usual.
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Example:
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@example
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ffmpeg -i file.mpg -vcodec copy -acodec ac3 -ab 384k test.mpg -acodec mp2 -ab 192k -newaudio
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@end example
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@item -alang @var{code}
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Set the ISO 639 language code (3 letters) of the current audio stream.
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@end table
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@section Advanced Audio options:
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@table @option
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@item -atag @var{fourcc/tag}
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Force audio tag/fourcc.
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@item -absf @var{bitstream_filter}
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Bitstream filters available are "dump_extra", "remove_extra", "noise", "mp3comp", "mp3decomp".
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@end table
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@section Subtitle options:
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@table @option
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@item -scodec @var{codec}
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Force subtitle codec ('copy' to copy stream).
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@item -newsubtitle
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Add a new subtitle stream to the current output stream.
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@item -slang @var{code}
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Set the ISO 639 language code (3 letters) of the current subtitle stream.
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@item -sn
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Disable subtitle recording.
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@item -sbsf @var{bitstream_filter}
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Bitstream filters available are "mov2textsub", "text2movsub".
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@example
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ffmpeg -i file.mov -an -vn -sbsf mov2textsub -scodec copy -f rawvideo sub.txt
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@end example
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@end table
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@section Audio/Video grab options
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@table @option
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@item -vc @var{channel}
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Set video grab channel (DV1394 only).
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@item -tvstd @var{standard}
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Set television standard (NTSC, PAL (SECAM)).
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@item -isync
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Synchronize read on input.
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@end table
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@section Advanced options
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@table @option
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@item -map @var{input_stream_id}[:@var{sync_stream_id}]
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Set stream mapping from input streams to output streams.
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Just enumerate the input streams in the order you want them in the output.
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@var{sync_stream_id} if specified sets the input stream to sync
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against.
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@item -map_meta_data @var{outfile}[,@var{metadata}]:@var{infile}[,@var{metadata}]
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Set meta data information of @var{outfile} from @var{infile}. Note that those
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are file indices (zero-based), not filenames.
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Optional @var{metadata} parameters specify, which metadata to copy - (g)lobal
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(i.e. metadata that applies to the whole file), per-(s)tream, per-(c)hapter or
625
per-(p)rogram. All metadata specifiers other than global must be followed by the
626
stream/chapter/program number. If metadata specifier is omitted, it defaults to
627
global.
628
For example to copy metadata from the first stream of the input file to global metadata
629
of the output file:
630
@example
631
ffmpeg -i in.ogg -map_meta_data 0:0,s0 out.mp3
632
@end example
633
@item -debug
634
Print specific debug info.
635
@item -benchmark
636
Show benchmarking information at the end of an encode.
637
Shows CPU time used and maximum memory consumption.
638
Maximum memory consumption is not supported on all systems,
639
it will usually display as 0 if not supported.
640
@item -dump
641
Dump each input packet.
642
@item -hex
643
When dumping packets, also dump the payload.
644
@item -bitexact
645
Only use bit exact algorithms (for codec testing).
646
@item -ps @var{size}
647
Set RTP payload size in bytes.
648
@item -re
649
Read input at native frame rate. Mainly used to simulate a grab device.
650
@item -loop_input
651
Loop over the input stream. Currently it works only for image
652
streams. This option is used for automatic FFserver testing.
653
@item -loop_output @var{number_of_times}
654
Repeatedly loop output for formats that support looping such as animated GIF
655
(0 will loop the output infinitely).
656
@item -threads @var{count}
657
Thread count.
658
@item -vsync @var{parameter}
659
Video sync method.
660
0   Each frame is passed with its timestamp from the demuxer to the muxer
661
1   Frames will be duplicated and dropped to achieve exactly the requested
662
    constant framerate.
663
2   Frames are passed through with their timestamp or dropped so as to prevent
664
    2 frames from having the same timestamp
665
-1  Chooses between 1 and 2 depending on muxer capabilities. This is the default method.
666

    
667
With -map you can select from
668
which stream the timestamps should be taken. You can leave either video or
669
audio unchanged and sync the remaining stream(s) to the unchanged one.
670
@item -async @var{samples_per_second}
671
Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
672
the parameter is the maximum samples per second by which the audio is changed.
673
-async 1 is a special case where only the start of the audio stream is corrected
674
without any later correction.
675
@item -copyts
676
Copy timestamps from input to output.
677
@item -shortest
678
Finish encoding when the shortest input stream ends.
679
@item -dts_delta_threshold
680
Timestamp discontinuity delta threshold.
681
@item -muxdelay @var{seconds}
682
Set the maximum demux-decode delay.
683
@item -muxpreload @var{seconds}
684
Set the initial demux-decode delay.
685
@item -streamid @var{output-stream-index}:@var{new-value}
686
Assign a new value to a stream's stream-id field in the next output file.
687
All stream-id fields are reset to default for each output file.
688

    
689
For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
690
an output mpegts file:
691
@example
692
ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
693
@end example
694
@end table
695

    
696
@section Preset files
697

    
698
A preset file contains a sequence of @var{option}=@var{value} pairs,
699
one for each line, specifying a sequence of options which would be
700
awkward to specify on the command line. Lines starting with the hash
701
('#') character are ignored and are used to provide comments. Check
702
the @file{ffpresets} directory in the FFmpeg source tree for examples.
703

    
704
Preset files are specified with the @code{vpre}, @code{apre},
705
@code{spre}, and @code{fpre} options. The @code{fpre} option takes the
706
filename of the preset instead of a preset name as input and can be
707
used for any kind of codec. For the @code{vpre}, @code{apre}, and
708
@code{spre} options, the options specified in a preset file are
709
applied to the currently selected codec of the same type as the preset
710
option.
711

    
712
The argument passed to the @code{vpre}, @code{apre}, and @code{spre}
713
preset options identifies the preset file to use according to the
714
following rules:
715

    
716
First ffmpeg searches for a file named @var{arg}.ffpreset in the
717
directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
718
the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg})
719
in that order. For example, if the argument is @code{libx264-max}, it will
720
search for the file @file{libx264-max.ffpreset}.
721

    
722
If no such file is found, then ffmpeg will search for a file named
723
@var{codec_name}-@var{arg}.ffpreset in the above-mentioned
724
directories, where @var{codec_name} is the name of the codec to which
725
the preset file options will be applied. For example, if you select
726
the video codec with @code{-vcodec libx264} and use @code{-vpre max},
727
then it will search for the file @file{libx264-max.ffpreset}.
728
@c man end
729

    
730
@chapter Tips
731
@c man begin TIPS
732

    
733
@itemize
734
@item
735
For streaming at very low bitrate application, use a low frame rate
736
and a small GOP size. This is especially true for RealVideo where
737
the Linux player does not seem to be very fast, so it can miss
738
frames. An example is:
739

    
740
@example
741
ffmpeg -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
742
@end example
743

    
744
@item
745
The parameter 'q' which is displayed while encoding is the current
746
quantizer. The value 1 indicates that a very good quality could
747
be achieved. The value 31 indicates the worst quality. If q=31 appears
748
too often, it means that the encoder cannot compress enough to meet
749
your bitrate. You must either increase the bitrate, decrease the
750
frame rate or decrease the frame size.
751

    
752
@item
753
If your computer is not fast enough, you can speed up the
754
compression at the expense of the compression ratio. You can use
755
'-me zero' to speed up motion estimation, and '-intra' to disable
756
motion estimation completely (you have only I-frames, which means it
757
is about as good as JPEG compression).
758

    
759
@item
760
To have very low audio bitrates, reduce the sampling frequency
761
(down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
762

    
763
@item
764
To have a constant quality (but a variable bitrate), use the option
765
'-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
766
quality).
767

    
768
@item
769
When converting video files, you can use the '-sameq' option which
770
uses the same quality factor in the encoder as in the decoder.
771
It allows almost lossless encoding.
772

    
773
@end itemize
774
@c man end TIPS
775

    
776
@chapter Examples
777
@c man begin EXAMPLES
778

    
779
@section Video and Audio grabbing
780

    
781
FFmpeg can grab video and audio from devices given that you specify the input
782
format and device.
783

    
784
@example
785
ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
786
@end example
787

    
788
Note that you must activate the right video source and channel before
789
launching FFmpeg with any TV viewer such as xawtv
790
(@url{http://linux.bytesex.org/xawtv/}) by Gerd Knorr. You also
791
have to set the audio recording levels correctly with a
792
standard mixer.
793

    
794
@section X11 grabbing
795

    
796
FFmpeg can grab the X11 display.
797

    
798
@example
799
ffmpeg -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
800
@end example
801

    
802
0.0 is display.screen number of your X11 server, same as
803
the DISPLAY environment variable.
804

    
805
@example
806
ffmpeg -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
807
@end example
808

    
809
0.0 is display.screen number of your X11 server, same as the DISPLAY environment
810
variable. 10 is the x-offset and 20 the y-offset for the grabbing.
811

    
812
@section Video and Audio file format conversion
813

    
814
* FFmpeg can use any supported file format and protocol as input:
815

    
816
Examples:
817

    
818
* You can use YUV files as input:
819

    
820
@example
821
ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
822
@end example
823

    
824
It will use the files:
825
@example
826
/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
827
/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
828
@end example
829

    
830
The Y files use twice the resolution of the U and V files. They are
831
raw files, without header. They can be generated by all decent video
832
decoders. You must specify the size of the image with the @option{-s} option
833
if FFmpeg cannot guess it.
834

    
835
* You can input from a raw YUV420P file:
836

    
837
@example
838
ffmpeg -i /tmp/test.yuv /tmp/out.avi
839
@end example
840

    
841
test.yuv is a file containing raw YUV planar data. Each frame is composed
842
of the Y plane followed by the U and V planes at half vertical and
843
horizontal resolution.
844

    
845
* You can output to a raw YUV420P file:
846

    
847
@example
848
ffmpeg -i mydivx.avi hugefile.yuv
849
@end example
850

    
851
* You can set several input files and output files:
852

    
853
@example
854
ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
855
@end example
856

    
857
Converts the audio file a.wav and the raw YUV video file a.yuv
858
to MPEG file a.mpg.
859

    
860
* You can also do audio and video conversions at the same time:
861

    
862
@example
863
ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
864
@end example
865

    
866
Converts a.wav to MPEG audio at 22050 Hz sample rate.
867

    
868
* You can encode to several formats at the same time and define a
869
mapping from input stream to output streams:
870

    
871
@example
872
ffmpeg -i /tmp/a.wav -ab 64k /tmp/a.mp2 -ab 128k /tmp/b.mp2 -map 0:0 -map 0:0
873
@end example
874

    
875
Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
876
file:index' specifies which input stream is used for each output
877
stream, in the order of the definition of output streams.
878

    
879
* You can transcode decrypted VOBs:
880

    
881
@example
882
ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec libmp3lame -ab 128k snatch.avi
883
@end example
884

    
885
This is a typical DVD ripping example; the input is a VOB file, the
886
output an AVI file with MPEG-4 video and MP3 audio. Note that in this
887
command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
888
GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
889
input video. Furthermore, the audio stream is MP3-encoded so you need
890
to enable LAME support by passing @code{--enable-libmp3lame} to configure.
891
The mapping is particularly useful for DVD transcoding
892
to get the desired audio language.
893

    
894
NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
895

    
896
* You can extract images from a video, or create a video from many images:
897

    
898
For extracting images from a video:
899
@example
900
ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
901
@end example
902

    
903
This will extract one video frame per second from the video and will
904
output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
905
etc. Images will be rescaled to fit the new WxH values.
906

    
907
If you want to extract just a limited number of frames, you can use the
908
above command in combination with the -vframes or -t option, or in
909
combination with -ss to start extracting from a certain point in time.
910

    
911
For creating a video from many images:
912
@example
913
ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
914
@end example
915

    
916
The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
917
composed of three digits padded with zeroes to express the sequence
918
number. It is the same syntax supported by the C printf function, but
919
only formats accepting a normal integer are suitable.
920

    
921
* You can put many streams of the same type in the output:
922

    
923
@example
924
ffmpeg -i test1.avi -i test2.avi -vcodec copy -acodec copy -vcodec copy -acodec copy test12.avi -newvideo -newaudio
925
@end example
926

    
927
In addition to the first video and audio streams, the resulting
928
output file @file{test12.avi} will contain the second video
929
and the second audio stream found in the input streams list.
930

    
931
The @code{-newvideo}, @code{-newaudio} and @code{-newsubtitle}
932
options have to be specified immediately after the name of the output
933
file to which you want to add them.
934
@c man end EXAMPLES
935

    
936
@include eval.texi
937
@include indevs.texi
938
@include outdevs.texi
939
@include protocols.texi
940
@include bitstream_filters.texi
941
@include filters.texi
942

    
943
@ignore
944

    
945
@setfilename ffmpeg
946
@settitle FFmpeg video converter
947

    
948
@c man begin SEEALSO
949
ffplay(1), ffprobe(1), ffserver(1) and the FFmpeg HTML documentation
950
@c man end
951

    
952
@c man begin AUTHORS
953
The FFmpeg developers
954
@c man end
955

    
956
@end ignore
957

    
958
@bye