Building libavfilter without that functionality makes little sense.

Based on the volume filter in FFmpeg written by Stefano Sabatini
<stefasab@gmail.com>.

The following commit will make it useless.

The crop_scale_vflip FATE test changes because of off-by-one differences
in output when vflipped slices are passed to sws.

It can be useful for debugging.

Based on a patch by Stefano Sabatini <stefano.sabatini-lala@poste.it>

Signed-off-by: Martin Storsjö <martin@martin.st>

Inspired by MPlayer's af_channels filter and SoX's remix effect.

It joins multiple input streams into one multi-channel output.

Based on current version of the asplit filter in FFmpeg written by
Stefano Sabatini and others.

Partially based on a patch by Robert Nagy <ronag89@gmail.com>

Based on a patch by Mina Nagy Zaki <mnzaki@gmail.com>

Also add the public interface libavfilter/buffersink.h.

Based on a commit by Stefano Sabatini.

The scale filter is used for internal colorspace conversions, so it must
always be present.

It's a part of public API.

The licence was changed from GPL to LGPL with explicit approval from
the original author.

See thread:
Subject: [FFmpeg-devel] [PATCH] lavfi: add rgbtestsrc source,
        ported from MPlayer libmpcodecs
Date: Mon, 11 Jul 2011 16:32:41 +0200

Signed-off-by: Anton Khirnov <anton@khirnov.net>

Signed-off-by: Anton Khirnov <anton@khirnov.net>

The ported filter supports named option parsing and more YUV formats.

Signed-off-by: Anton Khirnov <anton@khirnov.net>

With the following additions:
* support to gray format
* support to yuva420p format
* parametric luma/chroma/alpha radius
* consistency check on the radius values, avoid crashes with invalid values

Signed-off-by: Anton Khirnov <anton@khirnov.net>

This filter is a simple wrapper around the LUT filter.

Signed-off-by: Anton Khirnov <anton@khirnov.net>

Signed-off-by: Anton Khirnov <anton@khirnov.net>

Signed-off-by: Anton Khirnov <anton@khirnov.net>

Some fixes by Stefano.
For detailed authorship see SOC repo

Signed-off-by: Anton Khirnov <anton@khirnov.net>

Signed-off-by: Anton Khirnov <anton@khirnov.net>

With the following additions:
* support to anti-aliased glyph rendering
* support to UTF-8 text and Unicode chars rendering
* support for RGB packed formats
* fix minor errors and typos in the filter description
* extend/clarify examples in the filter description

Signed-off-by: Anton Khirnov <anton@khirnov.net>

Signed-off-by: Stefano Sabatini <stefano.sabatini-lala@poste.it>
Signed-off-by: Anton Khirnov <anton@khirnov.net>

Port fade filter from libavfilter soc repo, with minor fixes by
Stefano.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Signed-off-by: Anton Khirnov <anton@khirnov.net>

Signed-off-by: Mans Rullgard <mans@mansr.com>

See thread:
Subject: [PATCH] movie video source
Date: 2010-12-31 15:35:30 GMT

Signed-off-by: Janne Grunau <janne-ffmpeg@jannau.net>

code.

Originally committed as revision 26112 to svn://svn.ffmpeg.org/ffmpeg/trunk

FILTERNAME=ARGS and FILTERNAME:ARGS syntax.

The same filter class will be used for managing all the libopencv
filtering functions.

Originally committed as revision 26079 to svn://svn.ffmpeg.org/ffmpeg/trunk

Patch by Nolan L nol888 <=> gmail >=< com.

See thread:
Subject: [FFmpeg-devel] [PATCH] Port gradfun to libavfilter (GCI)
Date: Mon, 29 Nov 2010 07:18:14 -0500

Originally committed as revision 25942 to svn://svn.ffmpeg.org/ffmpeg/trunk

Patch by Baptiste with some fixes by me.

Originally committed as revision 25880 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 25855 to svn://svn.ffmpeg.org/ffmpeg/trunk

headers.

Originally committed as revision 25838 to svn://svn.ffmpeg.org/ffmpeg/trunk

aspect ratio.

Originally committed as revision 25800 to svn://svn.ffmpeg.org/ffmpeg/trunk

adopting Baptiste variant which is simpler and faster.

Originally committed as revision 25784 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 25657 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 25655 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 25525 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 25447 to svn://svn.ffmpeg.org/ffmpeg/trunk