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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:
575
@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
623
@item -map @var{input_stream_id}[:@var{sync_stream_id}]
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Set stream mapping from input streams to output streams.
625
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
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 value to a stream's stream-id field in the next output file.
716
All stream-id fields are reset to default for each output file.
717

    
718
For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
719
an output mpegts file:
720
@example
721
ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
722
@end example
723
@end table
724

    
725
@section Preset files
726

    
727
A preset file contains a sequence of @var{option}=@var{value} pairs,
728
one for each line, specifying a sequence of options which would be
729
awkward to specify on the command line. Lines starting with the hash
730
('#') character are ignored and are used to provide comments. Check
731
the @file{ffpresets} directory in the FFmpeg source tree for examples.
732

    
733
Preset files are specified with the @code{vpre}, @code{apre},
734
@code{spre}, and @code{fpre} options. The @code{fpre} option takes the
735
filename of the preset instead of a preset name as input and can be
736
used for any kind of codec. For the @code{vpre}, @code{apre}, and
737
@code{spre} options, the options specified in a preset file are
738
applied to the currently selected codec of the same type as the preset
739
option.
740

    
741
The argument passed to the @code{vpre}, @code{apre}, and @code{spre}
742
preset options identifies the preset file to use according to the
743
following rules:
744

    
745
First ffmpeg searches for a file named @var{arg}.ffpreset in the
746
directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
747
the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg})
748
in that order. For example, if the argument is @code{libx264-max}, it will
749
search for the file @file{libx264-max.ffpreset}.
750

    
751
If no such file is found, then ffmpeg will search for a file named
752
@var{codec_name}-@var{arg}.ffpreset in the above-mentioned
753
directories, where @var{codec_name} is the name of the codec to which
754
the preset file options will be applied. For example, if you select
755
the video codec with @code{-vcodec libx264} and use @code{-vpre max},
756
then it will search for the file @file{libx264-max.ffpreset}.
757
@c man end
758

    
759
@chapter Tips
760
@c man begin TIPS
761

    
762
@itemize
763
@item
764
For streaming at very low bitrate application, use a low frame rate
765
and a small GOP size. This is especially true for RealVideo where
766
the Linux player does not seem to be very fast, so it can miss
767
frames. An example is:
768

    
769
@example
770
ffmpeg -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
771
@end example
772

    
773
@item
774
The parameter 'q' which is displayed while encoding is the current
775
quantizer. The value 1 indicates that a very good quality could
776
be achieved. The value 31 indicates the worst quality. If q=31 appears
777
too often, it means that the encoder cannot compress enough to meet
778
your bitrate. You must either increase the bitrate, decrease the
779
frame rate or decrease the frame size.
780

    
781
@item
782
If your computer is not fast enough, you can speed up the
783
compression at the expense of the compression ratio. You can use
784
'-me zero' to speed up motion estimation, and '-intra' to disable
785
motion estimation completely (you have only I-frames, which means it
786
is about as good as JPEG compression).
787

    
788
@item
789
To have very low audio bitrates, reduce the sampling frequency
790
(down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
791

    
792
@item
793
To have a constant quality (but a variable bitrate), use the option
794
'-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
795
quality).
796

    
797
@item
798
When converting video files, you can use the '-sameq' option which
799
uses the same quality factor in the encoder as in the decoder.
800
It allows almost lossless encoding.
801

    
802
@end itemize
803
@c man end TIPS
804

    
805
@chapter Examples
806
@c man begin EXAMPLES
807

    
808
@section Video and Audio grabbing
809

    
810
FFmpeg can grab video and audio from devices given that you specify the input
811
format and device.
812

    
813
@example
814
ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
815
@end example
816

    
817
Note that you must activate the right video source and channel before
818
launching FFmpeg with any TV viewer such as xawtv
819
(@url{http://linux.bytesex.org/xawtv/}) by Gerd Knorr. You also
820
have to set the audio recording levels correctly with a
821
standard mixer.
822

    
823
@section X11 grabbing
824

    
825
FFmpeg can grab the X11 display.
826

    
827
@example
828
ffmpeg -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
829
@end example
830

    
831
0.0 is display.screen number of your X11 server, same as
832
the DISPLAY environment variable.
833

    
834
@example
835
ffmpeg -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
836
@end example
837

    
838
0.0 is display.screen number of your X11 server, same as the DISPLAY environment
839
variable. 10 is the x-offset and 20 the y-offset for the grabbing.
840

    
841
@section Video and Audio file format conversion
842

    
843
FFmpeg can use any supported file format and protocol as input:
844

    
845
Examples:
846
@itemize
847
@item
848
You can use YUV files as input:
849

    
850
@example
851
ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
852
@end example
853

    
854
It will use the files:
855
@example
856
/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
857
/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
858
@end example
859

    
860
The Y files use twice the resolution of the U and V files. They are
861
raw files, without header. They can be generated by all decent video
862
decoders. You must specify the size of the image with the @option{-s} option
863
if FFmpeg cannot guess it.
864

    
865
@item
866
You can input from a raw YUV420P file:
867

    
868
@example
869
ffmpeg -i /tmp/test.yuv /tmp/out.avi
870
@end example
871

    
872
test.yuv is a file containing raw YUV planar data. Each frame is composed
873
of the Y plane followed by the U and V planes at half vertical and
874
horizontal resolution.
875

    
876
@item
877
You can output to a raw YUV420P file:
878

    
879
@example
880
ffmpeg -i mydivx.avi hugefile.yuv
881
@end example
882

    
883
@item
884
You can set several input files and output files:
885

    
886
@example
887
ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
888
@end example
889

    
890
Converts the audio file a.wav and the raw YUV video file a.yuv
891
to MPEG file a.mpg.
892

    
893
@item
894
You can also do audio and video conversions at the same time:
895

    
896
@example
897
ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
898
@end example
899

    
900
Converts a.wav to MPEG audio at 22050 Hz sample rate.
901

    
902
@item
903
You can encode to several formats at the same time and define a
904
mapping from input stream to output streams:
905

    
906
@example
907
ffmpeg -i /tmp/a.wav -ab 64k /tmp/a.mp2 -ab 128k /tmp/b.mp2 -map 0:0 -map 0:0
908
@end example
909

    
910
Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
911
file:index' specifies which input stream is used for each output
912
stream, in the order of the definition of output streams.
913

    
914
@item
915
You can transcode decrypted VOBs:
916

    
917
@example
918
ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec libmp3lame -ab 128k snatch.avi
919
@end example
920

    
921
This is a typical DVD ripping example; the input is a VOB file, the
922
output an AVI file with MPEG-4 video and MP3 audio. Note that in this
923
command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
924
GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
925
input video. Furthermore, the audio stream is MP3-encoded so you need
926
to enable LAME support by passing @code{--enable-libmp3lame} to configure.
927
The mapping is particularly useful for DVD transcoding
928
to get the desired audio language.
929

    
930
NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
931

    
932
@item
933
You can extract images from a video, or create a video from many images:
934

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

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

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

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

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

    
958
@item
959
You can put many streams of the same type in the output:
960

    
961
@example
962
ffmpeg -i test1.avi -i test2.avi -vcodec copy -acodec copy -vcodec copy -acodec copy test12.avi -newvideo -newaudio
963
@end example
964

    
965
In addition to the first video and audio streams, the resulting
966
output file @file{test12.avi} will contain the second video
967
and the second audio stream found in the input streams list.
968

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

    
973
@end itemize
974
@c man end EXAMPLES
975

    
976
@include eval.texi
977
@include demuxers.texi
978
@include indevs.texi
979
@include outdevs.texi
980
@include protocols.texi
981
@include bitstream_filters.texi
982
@include filters.texi
983
@include metadata.texi
984

    
985
@ignore
986

    
987
@setfilename ffmpeg
988
@settitle FFmpeg video converter
989

    
990
@c man begin SEEALSO
991
ffplay(1), ffprobe(1), ffserver(1) and the FFmpeg HTML documentation
992
@c man end
993

    
994
@c man begin AUTHORS
995
The FFmpeg developers
996
@c man end
997

    
998
@end ignore
999

    
1000
@bye