PeerStreamer

@chapter Video Filters

@c man begin VIDEO FILTERS

When you configure your FFmpeg build, you can disable any of the

existing filters using --disable-filters.

The configure output will show the video filters included in your

build.

Below is a description of the currently available video filters.

@section crop

Crop the input video to @var{x}:@var{y}:@var{width}:@var{height}.

@example

./ffmpeg -i in.avi -vf "crop=0:0:0:240" out.avi

@end example

@var{x} and @var{y} specify the position of the top-left corner of the

output (non-cropped) area.

The default value of @var{x} and @var{y} is 0.

The @var{width} and @var{height} parameters specify the width and height

of the output (non-cropped) area.

A value of 0 is interpreted as the maximum possible size contained in

the area delimited by the top-left corner at position x:y.

For example the parameters:

@example

"crop=100:100:0:0"

@end example

will delimit the rectangle with the top-left corner placed at position

100:100 and the right-bottom corner corresponding to the right-bottom

corner of the input image.

The default value of @var{width} and @var{height} is 0.

@section format

Convert the input video to one of the specified pixel formats.

Libavfilter will try to pick one that is supported for the input to

the next filter.

The filter accepts a list of pixel format names, separated by ``:'',

for example ``yuv420p:monow:rgb24''.

The following command:

@example

./ffmpeg -i in.avi -vf "format=yuv420p" out.avi

@end example

will convert the input video to the format ``yuv420p''.

@section noformat

Force libavfilter not to use any of the specified pixel formats for the

input to the next filter.

The filter accepts a list of pixel format names, separated by ``:'',

for example ``yuv420p:monow:rgb24''.

The following command:

@example

./ffmpeg -i in.avi -vf "noformat=yuv420p, vflip" out.avi

@end example

will make libavfilter use a format different from ``yuv420p'' for the

input to the vflip filter.

@section null

Pass the source unchanged to the output.

@section pad

Add paddings to the input image, and places the original input at the

given coordinates @var{x}, @var{y}.

It accepts the following parameters:

@var{width}:@var{height}:@var{x}:@var{y}:@var{color}.

Follows the description of the accepted parameters.

@table @option

@item width, height

Specify the size of the output image with the paddings added. If the

value for @var{width} or @var{height} is 0, the corresponding input size

is used for the output.

The default value of @var{width} and @var{height} is 0.

@item x, y

Specify the offsets where to place the input image in the padded area

with respect to the top/left border of the output image.

The default value of @var{x} and @var{y} is 0.

@item color

Specify the color of the padded area, it can be the name of a color

(case insensitive match) or a 0xRRGGBB[AA] sequence.

The default value of @var{color} is ``black''.

@end table

@section scale

Scale the input video to @var{width}:@var{height} and/or convert the image format.

For example the command:

@example

./ffmpeg -i in.avi -vf "scale=200:100" out.avi

@end example

will scale the input video to a size of 200x100.

If the input image format is different from the format requested by

the next filter, the scale filter will convert the input to the

requested format.

If the value for @var{width} or @var{height} is 0, the respective input

size is used for the output.

If the value for @var{width} or @var{height} is -1, the scale filter will

use, for the respective output size, a value that maintains the aspect

ratio of the input image.

The default value of @var{width} and @var{height} is 0.

@section slicify

Pass the images of input video on to next video filter as multiple

slices.

@example

./ffmpeg -i in.avi -vf "slicify=32" out.avi

@end example

The filter accepts the slice height as parameter. If the parameter is

not specified it will use the default value of 16.

Adding this in the beginning of filter chains should make filtering

faster due to better use of the memory cache.

@section unsharp

Sharpen or blur the input video. It accepts the following parameters:

Negative values for the amount will blur the input video, while positive

values will sharpen. All parameters are optional and default to the

equivalent of the string '5:5:1.0:0:0:0.0'.

@table @option

@item luma_msize_x

Set the luma matrix horizontal size. It can be an integer between 3

and 13, default value is 5.

@item luma_msize_y

Set the luma matrix vertical size. It can be an integer between 3

and 13, default value is 5.

@item luma_amount

Set the luma effect strength. It can be a float number between -2.0

and 5.0, default value is 1.0.

@item chroma_msize_x

Set the chroma matrix horizontal size. It can be an integer between 3

and 13, default value is 0.

@item chroma_msize_y

Set the chroma matrix vertical size. It can be an integer between 3

and 13, default value is 0.

@item luma_amount

Set the chroma effect strength. It can be a float number between -2.0

and 5.0, default value is 0.0.

@end table

@example

# Strong luma sharpen effect parameters

unsharp=7:7:2.5

# Strong blur of both luma and chroma parameters

unsharp=7:7:-2:7:7:-2

# Use the default values with @command{ffmpeg}

./ffmpeg -i in.avi -vf "unsharp" out.mp4

@end example

@section vflip

Flip the input video vertically.

@example

./ffmpeg -i in.avi -vf "vflip" out.avi

@end example

@c man end VIDEO FILTERS

@chapter Video Sources

@c man begin VIDEO SOURCES

Below is a description of the currently available video sources.

@section nullsrc

Null video source, never return images. It is mainly useful as a

template and to be employed in analysis / debugging tools.

It accepts as optional parameter a string of the form

@var{width}:@var{height}, where @var{width} and @var{height} specify the size of

the configured source.

The default values of @var{width} and @var{height} are respectively 352

and 288 (corresponding to the CIF size format).

@c man end VIDEO SOURCES

@chapter Video Sinks

@c man begin VIDEO SINKS

Below is a description of the currently available video sinks.

@section nullsink

Null video sink, do absolutely nothing with the input video. It is

mainly useful as a template and to be employed in analysis / debugging

tools.

@c man end VIDEO SINKS