ffmpeg / doc / ffmpeg-doc.texi @ 4ad08021
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\input texinfo @c -*- texinfo -*- |
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|
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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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|
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@chapter Synopsis |
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|
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The generic syntax is: |
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|
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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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|
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@chapter Description |
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@c man begin DESCRIPTION |
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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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The format option may be needed for raw input files. |
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|
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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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|
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@c man end DESCRIPTION |
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|
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@chapter Options |
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@c man begin OPTIONS |
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|
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@include fftools-common-opts.texi |
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|
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@section Main options |
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|
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@table @option |
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|
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@item -f @var{fmt} |
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Force format. |
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|
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@item -i @var{filename} |
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input file name |
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|
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@item -y |
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Overwrite output files. |
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|
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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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|
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@item -fs @var{limit_size} |
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Set the file size limit. |
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|
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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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|
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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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|
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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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|
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@item -metadata @var{key}=@var{value} |
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Set a metadata key/value pair. |
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|
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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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|
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@item -v @var{number} |
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Set the logging verbosity level. |
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|
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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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|
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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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|
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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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|
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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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|
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@item -dframes @var{number} |
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Set the number of data frames to record. |
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|
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@item -scodec @var{codec} |
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Force subtitle codec ('copy' to copy stream). |
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|
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@item -newsubtitle |
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Add a new subtitle stream to the current output stream. |
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|
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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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|
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@end table |
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|
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@section Video Options |
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|
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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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|
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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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|
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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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|
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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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|
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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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|
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@item -newvideo |
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Add a new video stream to the current output stream. |
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|
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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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|
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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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|
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@end table |
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|
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@section Advanced Video Options |
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|
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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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|
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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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|
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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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|
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@item -rc_init_cplx @var{complexity} |
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initial complexity for single pass encoding |
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@item -b_qfactor @var{factor} |
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qp factor between P- and B-frames |
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@item -i_qfactor @var{factor} |
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qp factor between P- and I-frames |
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@item -b_qoffset @var{offset} |
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qp offset between P- and B-frames |
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@item -i_qoffset @var{offset} |
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qp offset between P- and I-frames |
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@item -rc_eq @var{equation} |
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Set rate control equation (@pxref{FFmpeg formula |
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evaluator}) (default = @code{tex^qComp}). |
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@item -rc_override @var{override} |
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rate control override for specific intervals |
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@item -me_method @var{method} |
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Set motion estimation method to @var{method}. |
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Available methods are (from lowest to best quality): |
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@table @samp |
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@item zero |
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Try just the (0, 0) vector. |
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@item phods |
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@item log |
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@item x1 |
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@item hex |
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@item umh |
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@item epzs |
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(default method) |
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@item full |
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exhaustive search (slow and marginally better than epzs) |
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@end table |
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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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@section Audio Options |
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|
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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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|
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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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|
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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 |
542 |
|
543 |
@section Advanced Audio options: |
544 |
|
545 |
@table @option |
546 |
@item -atag @var{fourcc/tag} |
547 |
Force audio tag/fourcc. |
548 |
@item -absf @var{bitstream_filter} |
549 |
Bitstream filters available are "dump_extra", "remove_extra", "noise", "mp3comp", "mp3decomp". |
550 |
@end table |
551 |
|
552 |
@section Subtitle options: |
553 |
|
554 |
@table @option |
555 |
@item -scodec @var{codec} |
556 |
Force subtitle codec ('copy' to copy stream). |
557 |
@item -newsubtitle |
558 |
Add a new subtitle stream to the current output stream. |
559 |
@item -slang @var{code} |
560 |
Set the ISO 639 language code (3 letters) of the current subtitle stream. |
561 |
@item -sn |
562 |
Disable subtitle recording. |
563 |
@item -sbsf @var{bitstream_filter} |
564 |
Bitstream filters available are "mov2textsub", "text2movsub". |
565 |
@example |
566 |
ffmpeg -i file.mov -an -vn -sbsf mov2textsub -scodec copy -f rawvideo sub.txt |
567 |
@end example |
568 |
@end table |
569 |
|
570 |
@section Audio/Video grab options |
571 |
|
572 |
@table @option |
573 |
@item -vc @var{channel} |
574 |
Set video grab channel (DV1394 only). |
575 |
@item -tvstd @var{standard} |
576 |
Set television standard (NTSC, PAL (SECAM)). |
577 |
@item -isync |
578 |
Synchronize read on input. |
579 |
@end table |
580 |
|
581 |
@section Advanced options |
582 |
|
583 |
@table @option |
584 |
@item -map @var{input_stream_id}[:@var{sync_stream_id}] |
585 |
Set stream mapping from input streams to output streams. |
586 |
Just enumerate the input streams in the order you want them in the output. |
587 |
@var{sync_stream_id} if specified sets the input stream to sync |
588 |
against. |
589 |
@item -map_meta_data @var{outfile}:@var{infile} |
590 |
Set meta data information of @var{outfile} from @var{infile}. |
591 |
@item -debug |
592 |
Print specific debug info. |
593 |
@item -benchmark |
594 |
Show benchmarking information at the end of an encode. |
595 |
Shows CPU time used and maximum memory consumption. |
596 |
Maximum memory consumption is not supported on all systems, |
597 |
it will usually display as 0 if not supported. |
598 |
@item -dump |
599 |
Dump each input packet. |
600 |
@item -hex |
601 |
When dumping packets, also dump the payload. |
602 |
@item -bitexact |
603 |
Only use bit exact algorithms (for codec testing). |
604 |
@item -ps @var{size} |
605 |
Set RTP payload size in bytes. |
606 |
@item -re |
607 |
Read input at native frame rate. Mainly used to simulate a grab device. |
608 |
@item -loop_input |
609 |
Loop over the input stream. Currently it works only for image |
610 |
streams. This option is used for automatic FFserver testing. |
611 |
@item -loop_output @var{number_of_times} |
612 |
Repeatedly loop output for formats that support looping such as animated GIF |
613 |
(0 will loop the output infinitely). |
614 |
@item -threads @var{count} |
615 |
Thread count. |
616 |
@item -vsync @var{parameter} |
617 |
Video sync method. |
618 |
0 Each frame is passed with its timestamp from the demuxer to the muxer |
619 |
1 Frames will be duplicated and dropped to achieve exactly the requested |
620 |
constant framerate. |
621 |
2 Frames are passed through with their timestamp or dropped so as to prevent |
622 |
2 frames from having the same timestamp |
623 |
-1 Chooses between 1 and 2 depending on muxer capabilities. This is the default method. |
624 |
|
625 |
With -map you can select from |
626 |
which stream the timestamps should be taken. You can leave either video or |
627 |
audio unchanged and sync the remaining stream(s) to the unchanged one. |
628 |
@item -async @var{samples_per_second} |
629 |
Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps, |
630 |
the parameter is the maximum samples per second by which the audio is changed. |
631 |
-async 1 is a special case where only the start of the audio stream is corrected |
632 |
without any later correction. |
633 |
@item -copyts |
634 |
Copy timestamps from input to output. |
635 |
@item -shortest |
636 |
Finish encoding when the shortest input stream ends. |
637 |
@item -dts_delta_threshold |
638 |
Timestamp discontinuity delta threshold. |
639 |
@item -muxdelay @var{seconds} |
640 |
Set the maximum demux-decode delay. |
641 |
@item -muxpreload @var{seconds} |
642 |
Set the initial demux-decode delay. |
643 |
@item -streamid @var{output-stream-index}:@var{new-value} |
644 |
Assign a new value to a stream's stream-id field in the next output file. |
645 |
All stream-id fields are reset to default for each output file. |
646 |
|
647 |
For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for |
648 |
an output mpegts file: |
649 |
@example |
650 |
ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts |
651 |
@end example |
652 |
@end table |
653 |
|
654 |
@section Preset files |
655 |
|
656 |
A preset file contains a sequence of @var{option}=@var{value} pairs, |
657 |
one for each line, specifying a sequence of options which would be |
658 |
awkward to specify on the command line. Lines starting with the hash |
659 |
('#') character are ignored and are used to provide comments. Check |
660 |
the @file{ffpresets} directory in the FFmpeg source tree for examples. |
661 |
|
662 |
Preset files are specified with the @code{vpre}, @code{apre}, |
663 |
@code{spre}, and @code{fpre} options. The @code{fpre} option takes the |
664 |
filename of the preset instead of a preset name as input and can be |
665 |
used for any kind of codec. For the @code{vpre}, @code{apre}, and |
666 |
@code{spre} options, the options specified in a preset file are |
667 |
applied to the currently selected codec of the same type as the preset |
668 |
option. |
669 |
|
670 |
The argument passed to the @code{vpre}, @code{apre}, and @code{spre} |
671 |
preset options identifies the preset file to use according to the |
672 |
following rules: |
673 |
|
674 |
First ffmpeg searches for a file named @var{arg}.ffpreset in the |
675 |
directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in |
676 |
the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg}) |
677 |
in that order. For example, if the argument is @code{libx264-max}, it will |
678 |
search for the file @file{libx264-max.ffpreset}. |
679 |
|
680 |
If no such file is found, then ffmpeg will search for a file named |
681 |
@var{codec_name}-@var{arg}.ffpreset in the above-mentioned |
682 |
directories, where @var{codec_name} is the name of the codec to which |
683 |
the preset file options will be applied. For example, if you select |
684 |
the video codec with @code{-vcodec libx264} and use @code{-vpre max}, |
685 |
then it will search for the file @file{libx264-max.ffpreset}. |
686 |
|
687 |
@anchor{FFmpeg formula evaluator} |
688 |
@section FFmpeg formula evaluator |
689 |
|
690 |
When evaluating a rate control string, FFmpeg uses an internal formula |
691 |
evaluator. |
692 |
|
693 |
The following binary operators are available: @code{+}, @code{-}, |
694 |
@code{*}, @code{/}, @code{^}. |
695 |
|
696 |
The following unary operators are available: @code{+}, @code{-}, |
697 |
@code{(...)}. |
698 |
|
699 |
The following statements are available: @code{ld}, @code{st}, |
700 |
@code{while}. |
701 |
|
702 |
The following functions are available: |
703 |
@table @var |
704 |
@item sinh(x) |
705 |
@item cosh(x) |
706 |
@item tanh(x) |
707 |
@item sin(x) |
708 |
@item cos(x) |
709 |
@item tan(x) |
710 |
@item atan(x) |
711 |
@item asin(x) |
712 |
@item acos(x) |
713 |
@item exp(x) |
714 |
@item log(x) |
715 |
@item abs(x) |
716 |
@item squish(x) |
717 |
@item gauss(x) |
718 |
@item mod(x, y) |
719 |
@item max(x, y) |
720 |
@item min(x, y) |
721 |
@item eq(x, y) |
722 |
@item gte(x, y) |
723 |
@item gt(x, y) |
724 |
@item lte(x, y) |
725 |
@item lt(x, y) |
726 |
@item bits2qp(bits) |
727 |
@item qp2bits(qp) |
728 |
@end table |
729 |
|
730 |
The following constants are available: |
731 |
@table @var |
732 |
@item PI |
733 |
@item E |
734 |
@item iTex |
735 |
@item pTex |
736 |
@item tex |
737 |
@item mv |
738 |
@item fCode |
739 |
@item iCount |
740 |
@item mcVar |
741 |
@item var |
742 |
@item isI |
743 |
@item isP |
744 |
@item isB |
745 |
@item avgQP |
746 |
@item qComp |
747 |
@item avgIITex |
748 |
@item avgPITex |
749 |
@item avgPPTex |
750 |
@item avgBPTex |
751 |
@item avgTex |
752 |
@end table |
753 |
|
754 |
@c man end |
755 |
|
756 |
@chapter Tips |
757 |
@c man begin TIPS |
758 |
|
759 |
@itemize |
760 |
@item |
761 |
For streaming at very low bitrate application, use a low frame rate |
762 |
and a small GOP size. This is especially true for RealVideo where |
763 |
the Linux player does not seem to be very fast, so it can miss |
764 |
frames. An example is: |
765 |
|
766 |
@example |
767 |
ffmpeg -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm |
768 |
@end example |
769 |
|
770 |
@item |
771 |
The parameter 'q' which is displayed while encoding is the current |
772 |
quantizer. The value 1 indicates that a very good quality could |
773 |
be achieved. The value 31 indicates the worst quality. If q=31 appears |
774 |
too often, it means that the encoder cannot compress enough to meet |
775 |
your bitrate. You must either increase the bitrate, decrease the |
776 |
frame rate or decrease the frame size. |
777 |
|
778 |
@item |
779 |
If your computer is not fast enough, you can speed up the |
780 |
compression at the expense of the compression ratio. You can use |
781 |
'-me zero' to speed up motion estimation, and '-intra' to disable |
782 |
motion estimation completely (you have only I-frames, which means it |
783 |
is about as good as JPEG compression). |
784 |
|
785 |
@item |
786 |
To have very low audio bitrates, reduce the sampling frequency |
787 |
(down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3). |
788 |
|
789 |
@item |
790 |
To have a constant quality (but a variable bitrate), use the option |
791 |
'-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst |
792 |
quality). |
793 |
|
794 |
@item |
795 |
When converting video files, you can use the '-sameq' option which |
796 |
uses the same quality factor in the encoder as in the decoder. |
797 |
It allows almost lossless encoding. |
798 |
|
799 |
@end itemize |
800 |
@c man end TIPS |
801 |
|
802 |
@chapter Examples |
803 |
@c man begin EXAMPLES |
804 |
|
805 |
@section Video and Audio grabbing |
806 |
|
807 |
FFmpeg can grab video and audio from devices given that you specify the input |
808 |
format and device. |
809 |
|
810 |
@example |
811 |
ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg |
812 |
@end example |
813 |
|
814 |
Note that you must activate the right video source and channel before |
815 |
launching FFmpeg with any TV viewer such as xawtv |
816 |
(@url{http://linux.bytesex.org/xawtv/}) by Gerd Knorr. You also |
817 |
have to set the audio recording levels correctly with a |
818 |
standard mixer. |
819 |
|
820 |
@section X11 grabbing |
821 |
|
822 |
FFmpeg can grab the X11 display. |
823 |
|
824 |
@example |
825 |
ffmpeg -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg |
826 |
@end example |
827 |
|
828 |
0.0 is display.screen number of your X11 server, same as |
829 |
the DISPLAY environment variable. |
830 |
|
831 |
@example |
832 |
ffmpeg -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg |
833 |
@end example |
834 |
|
835 |
0.0 is display.screen number of your X11 server, same as the DISPLAY environment |
836 |
variable. 10 is the x-offset and 20 the y-offset for the grabbing. |
837 |
|
838 |
@section Video and Audio file format conversion |
839 |
|
840 |
* FFmpeg can use any supported file format and protocol as input: |
841 |
|
842 |
Examples: |
843 |
|
844 |
* You can use YUV files as input: |
845 |
|
846 |
@example |
847 |
ffmpeg -i /tmp/test%d.Y /tmp/out.mpg |
848 |
@end example |
849 |
|
850 |
It will use the files: |
851 |
@example |
852 |
/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V, |
853 |
/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc... |
854 |
@end example |
855 |
|
856 |
The Y files use twice the resolution of the U and V files. They are |
857 |
raw files, without header. They can be generated by all decent video |
858 |
decoders. You must specify the size of the image with the @option{-s} option |
859 |
if FFmpeg cannot guess it. |
860 |
|
861 |
* You can input from a raw YUV420P file: |
862 |
|
863 |
@example |
864 |
ffmpeg -i /tmp/test.yuv /tmp/out.avi |
865 |
@end example |
866 |
|
867 |
test.yuv is a file containing raw YUV planar data. Each frame is composed |
868 |
of the Y plane followed by the U and V planes at half vertical and |
869 |
horizontal resolution. |
870 |
|
871 |
* You can output to a raw YUV420P file: |
872 |
|
873 |
@example |
874 |
ffmpeg -i mydivx.avi hugefile.yuv |
875 |
@end example |
876 |
|
877 |
* You can set several input files and output files: |
878 |
|
879 |
@example |
880 |
ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg |
881 |
@end example |
882 |
|
883 |
Converts the audio file a.wav and the raw YUV video file a.yuv |
884 |
to MPEG file a.mpg. |
885 |
|
886 |
* You can also do audio and video conversions at the same time: |
887 |
|
888 |
@example |
889 |
ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2 |
890 |
@end example |
891 |
|
892 |
Converts a.wav to MPEG audio at 22050 Hz sample rate. |
893 |
|
894 |
* You can encode to several formats at the same time and define a |
895 |
mapping from input stream to output streams: |
896 |
|
897 |
@example |
898 |
ffmpeg -i /tmp/a.wav -ab 64k /tmp/a.mp2 -ab 128k /tmp/b.mp2 -map 0:0 -map 0:0 |
899 |
@end example |
900 |
|
901 |
Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map |
902 |
file:index' specifies which input stream is used for each output |
903 |
stream, in the order of the definition of output streams. |
904 |
|
905 |
* You can transcode decrypted VOBs: |
906 |
|
907 |
@example |
908 |
ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec libmp3lame -ab 128k snatch.avi |
909 |
@end example |
910 |
|
911 |
This is a typical DVD ripping example; the input is a VOB file, the |
912 |
output an AVI file with MPEG-4 video and MP3 audio. Note that in this |
913 |
command we use B-frames so the MPEG-4 stream is DivX5 compatible, and |
914 |
GOP size is 300 which means one intra frame every 10 seconds for 29.97fps |
915 |
input video. Furthermore, the audio stream is MP3-encoded so you need |
916 |
to enable LAME support by passing @code{--enable-libmp3lame} to configure. |
917 |
The mapping is particularly useful for DVD transcoding |
918 |
to get the desired audio language. |
919 |
|
920 |
NOTE: To see the supported input formats, use @code{ffmpeg -formats}. |
921 |
|
922 |
* You can extract images from a video, or create a video from many images: |
923 |
|
924 |
For extracting images from a video: |
925 |
@example |
926 |
ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg |
927 |
@end example |
928 |
|
929 |
This will extract one video frame per second from the video and will |
930 |
output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg}, |
931 |
etc. Images will be rescaled to fit the new WxH values. |
932 |
|
933 |
If you want to extract just a limited number of frames, you can use the |
934 |
above command in combination with the -vframes or -t option, or in |
935 |
combination with -ss to start extracting from a certain point in time. |
936 |
|
937 |
For creating a video from many images: |
938 |
@example |
939 |
ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi |
940 |
@end example |
941 |
|
942 |
The syntax @code{foo-%03d.jpeg} specifies to use a decimal number |
943 |
composed of three digits padded with zeroes to express the sequence |
944 |
number. It is the same syntax supported by the C printf function, but |
945 |
only formats accepting a normal integer are suitable. |
946 |
|
947 |
* You can put many streams of the same type in the output: |
948 |
|
949 |
@example |
950 |
ffmpeg -i test1.avi -i test2.avi -vcodec copy -acodec copy -vcodec copy -acodec copy test12.avi -newvideo -newaudio |
951 |
@end example |
952 |
|
953 |
In addition to the first video and audio streams, the resulting |
954 |
output file @file{test12.avi} will contain the second video |
955 |
and the second audio stream found in the input streams list. |
956 |
|
957 |
The @code{-newvideo}, @code{-newaudio} and @code{-newsubtitle} |
958 |
options have to be specified immediately after the name of the output |
959 |
file to which you want to add them. |
960 |
@c man end EXAMPLES |
961 |
|
962 |
@include indevs.texi |
963 |
@include outdevs.texi |
964 |
@include protocols.texi |
965 |
@include filters.texi |
966 |
|
967 |
@ignore |
968 |
|
969 |
@setfilename ffmpeg |
970 |
@settitle FFmpeg video converter |
971 |
|
972 |
@c man begin SEEALSO |
973 |
ffplay(1), ffprobe(1), ffserver(1) and the FFmpeg HTML documentation |
974 |
@c man end |
975 |
|
976 |
@c man begin AUTHORS |
977 |
The FFmpeg developers |
978 |
@c man end |
979 |
|
980 |
@end ignore |
981 |
|
982 |
@bye |