For more information read:
@url{http://jackaudio.org/}
+@section lavfi
+
+Libavfilter input virtual device.
+
+This input device reads data from the open output pads of a libavfilter
+filtergraph.
+
+For each filtergraph open output, the input device will create a
+corresponding stream which is mapped to the generated output. Currently
+only video data is supported. The filtergraph is specified through the
+option @option{graph}.
+
+To enable this input device, you need to configure your build with
+@code{--enable-libavfilter}.
+
+@subsection Options
+
+@table @option
+
+@item graph
+Specify the filtergraph to use as input. Each video open output must be
+labelled by a unique string of the form "out@var{N}", where @var{N} is a
+number starting from 0 corresponding to the mapped input stream
+generated by the device.
+The first unlabelled output is automatically assigned to the "out0"
+label, but all the others need to be specified explicitely.
+
+If not specified defaults to the filename specified for the input
+device.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Create a color video stream and play it back with @file{ffplay}:
+@example
+ffplay -f lavfi -graph "color=pink [out0]" dummy
+@end example
+
+@item
+As the previous example, but use filename for specifying the graph
+description, and omit the "out0" label:
+@example
+ffplay -f lavfi color=pink
+@end example
+
+@item
+Create three different video test filtered sources and play them:
+@example
+ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3
+@end example
+@end itemize
+
@section libdc1394
IIDC1394 input device, based on libdc1394 and libraw1394.
ffmpeg -f x11grab -r 25 -s cif -i :0.0 out.mpg
# Grab at position 10,20.
-ffmpeg -f x11grab -25 -s cif -i :0.0+10,20 out.mpg
+ffmpeg -f x11grab -r 25 -s cif -i :0.0+10,20 out.mpg
+@end example
+
+@subsection @var{follow_mouse} AVOption
+
+The syntax is:
+@example
+-follow_mouse centered|@var{PIXELS}
+@end example
+
+When it is specified with "centered", the grabbing region follows the mouse
+pointer and keeps the pointer at the center of region; otherwise, the region
+follows only when the mouse pointer reaches within @var{PIXELS} (greater than
+zero) to the edge of region.
+
+For example:
+@example
+ffmpeg -f x11grab -follow_mouse centered -r 25 -s cif -i :0.0 out.mpg
+
+# Follows only when the mouse pointer reaches within 100 pixels to edge
+ffmpeg -f x11grab -follow_mouse 100 -r 25 -s cif -i :0.0 out.mpg
+@end example
+
+@subsection @var{show_region} AVOption
+
+The syntax is:
+@example
+-show_region 1
+@end example
+
+If @var{show_region} AVOption is specified with @var{1}, then the grabbing
+region will be indicated on screen. With this option, it's easy to know what is
+being grabbed if only a portion of the screen is grabbed.
+
+For example:
+@example
+ffmpeg -f x11grab -show_region 1 -r 25 -s cif -i :0.0+10,20 out.mpg
+
+# With follow_mouse
+ffmpeg -f x11grab -follow_mouse centered -show_region 1 -r 25 -s cif -i :0.0 out.mpg
@end example
@c man end INPUT DEVICES