\input texinfo @c -*- texinfo -*-
-@settitle FFmpeg Documentation
+@settitle ffmpeg Documentation
@titlepage
-@center @titlefont{FFmpeg Documentation}
+@center @titlefont{ffmpeg Documentation}
@end titlepage
@top
@chapter Description
@c man begin DESCRIPTION
-FFmpeg is a very fast video and audio converter. It can also grab from
-a live audio/video source.
+ffmpeg is a very fast video and audio converter that can also grab from
+a live audio/video source. It can also convert between arbitrary sample
+rates and resize video on the fly with a high quality polyphase filter.
The command line interface is designed to be intuitive, in the sense
-that FFmpeg tries to figure out all parameters that can possibly be
+that ffmpeg tries to figure out all parameters that can possibly be
derived automatically. You usually only have to specify the target
bitrate you want.
-FFmpeg can also convert from any sample rate to any other, and resize
-video on the fly with a high quality polyphase filter.
-
As a general rule, options are applied to the next specified
file. Therefore, order is important, and you can have the same
option on the command line multiple times. Each occurrence is
The format option may be needed for raw input files.
-By default, FFmpeg tries to convert as losslessly as possible: It
+By default ffmpeg tries to convert as losslessly as possible: It
uses the same audio and video parameters for the outputs as the one
specified for the inputs.
@section Video Options
@table @option
-@item -b @var{bitrate}
-Set the video bitrate in bit/s (default = 200 kb/s).
@item -vframes @var{number}
Set the number of video frames to record.
@item -r @var{fps}
@end table
@item -aspect @var{aspect}
-Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).
+Set the video display aspect ratio specified by @var{aspect}.
+
+@var{aspect} can be a floating point number string, or a string of the
+form @var{num}:@var{den}, where @var{num} and @var{den} are the
+numerator and denominator of the aspect ratio. For example "4:3",
+"16:9", "1.3333", and "1.7777" are valid argument values.
+
@item -croptop @var{size}
@item -cropbottom @var{size}
@item -cropleft @var{size}
Force video codec to @var{codec}. Use the @code{copy} special value to
tell that the raw codec data must be copied as is.
@item -sameq
-Use same video quality as source (implies VBR).
+Use same quantizer as source (implies VBR).
@item -pass @var{n}
Select the pass number (1 or 2). It is used to do two-pass
macroblock decision
@table @samp
@item 0
-FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in FFmpeg).
+FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in ffmpeg).
@item 1
FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
@item 2
@item -aframes @var{number}
Set the number of audio frames to record.
@item -ar @var{freq}
-Set the audio sampling frequency. For input streams it is set by
-default to 44100 Hz, for output streams it is set by default to the
-frequency of the input stream. If the input file has audio streams
-with different frequencies, the behaviour is undefined.
-@item -ab @var{bitrate}
-Set the audio bitrate in bit/s (default = 64k).
+Set the audio sampling frequency. For output streams it is set by
+default to the frequency of the corresponding input stream. For input
+streams this option only makes sense for audio grabbing devices and raw
+demuxers and is mapped to the corresponding demuxer options.
@item -aq @var{q}
Set the audio quality (codec-specific, VBR).
@item -ac @var{channels}
-Set the number of audio channels. For input streams it is set by
-default to 1, for output streams it is set by default to the same
-number of audio channels in input. If the input file has audio streams
-with different channel count, the behaviour is undefined.
+Set the number of audio channels. For output streams it is set by
+default to the number of input audio channels. For input streams
+this option only makes sense for audio grabbing devices and raw demuxers
+and is mapped to the corresponding demuxer options.
@item -an
Disable audio recording.
@item -acodec @var{codec}
@item -loop_input
Loop over the input stream. Currently it works only for image
streams. This option is used for automatic FFserver testing.
+This option is deprecated, use -loop.
@item -loop_output @var{number_of_times}
Repeatedly loop output for formats that support looping such as animated GIF
(0 will loop the output infinitely).
+This option is deprecated, use -loop.
@item -threads @var{count}
Thread count.
@item -vsync @var{parameter}
@section Video and Audio grabbing
-FFmpeg can grab video and audio from devices given that you specify the input
-format and device.
+If you specify the input format and device then ffmpeg can grab video
+and audio directly.
@example
ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
@end example
Note that you must activate the right video source and channel before
-launching FFmpeg with any TV viewer such as xawtv
-(@url{http://linux.bytesex.org/xawtv/}) by Gerd Knorr. You also
+launching ffmpeg with any TV viewer such as
+@uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also
have to set the audio recording levels correctly with a
standard mixer.
@section X11 grabbing
-FFmpeg can grab the X11 display.
+Grab the X11 display with ffmpeg via
@example
ffmpeg -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
@section Video and Audio file format conversion
-FFmpeg can use any supported file format and protocol as input:
+Any supported file format and protocol can serve as input to ffmpeg:
Examples:
@itemize
The Y files use twice the resolution of the U and V files. They are
raw files, without header. They can be generated by all decent video
decoders. You must specify the size of the image with the @option{-s} option
-if FFmpeg cannot guess it.
+if ffmpeg cannot guess it.
@item
You can input from a raw YUV420P file:
@ignore
@setfilename ffmpeg
-@settitle FFmpeg video converter
+@settitle ffmpeg video converter
@c man begin SEEALSO
ffplay(1), ffprobe(1), ffserver(1) and the Libav HTML documentation
projects / ffmpeg / blobdiff