lavfi: add pp filter.

Ported from MPlayer. Original author is A'rpi, with various
contributions from Michael Niedermayer. The original documentation was
mostly written by Diego Biurrun. See the MPlayer history for full
credits.

The filter is under GPL like the original filter, even if it differs
quite a lot. There is not much point in making it LGPL since pp is under
GPL.

1 files changed, 168 insertions, 0 deletions

diff --git a/doc/filters.texi b/doc/filters.texi
index f456d03617..3e37b5302d 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -3423,6 +3423,174 @@ format=monow, pixdesctest
 
 can be used to test the monowhite pixel format descriptor definition.
 
+@section pp
+
+Enable the specified chain of postprocessing subfilters using libpostproc. This
+library should be automatically selected with a GPL build (@code{--enable-gpl}).
+Subfilters must be separated by '/' and can be disabled by prepending a '-'.
+Each subfilter and some options have a short and a long name that can be used
+interchangeably, i.e. dr/dering are the same.
+
+All subfilters share common options to determine their scope:
+
+@table @option
+@item a/autoq
+Honor the quality commands for this subfilter.
+
+@item c/chrom
+Do chrominance filtering, too (default).
+
+@item y/nochrom
+Do luminance filtering only (no chrominance).
+
+@item n/noluma
+Do chrominance filtering only (no luminance).
+@end table
+
+These options can be appended after the subfilter name, separated by a ':'.
+
+Available subfilters are:
+
+@table @option
+@item hb/hdeblock[:difference[:flatness]]
+Horizontal deblocking filter
+@table @option
+@item difference
+Difference factor where higher values mean more deblocking (default: @code{32}).
+@item flatness
+Flatness threshold where lower values mean more deblocking (default: @code{39}).
+@end table
+
+@item vb/vdeblock[:difference[:flatness]]
+Vertical deblocking filter
+@table @option
+@item difference
+Difference factor where higher values mean more deblocking (default: @code{32}).
+@item flatness
+Flatness threshold where lower values mean more deblocking (default: @code{39}).
+@end table
+
+@item ha/hadeblock[:difference[:flatness]]
+Accurate horizontal deblocking filter
+@table @option
+@item difference
+Difference factor where higher values mean more deblocking (default: @code{32}).
+@item flatness
+Flatness threshold where lower values mean more deblocking (default: @code{39}).
+@end table
+
+@item va/vadeblock[:difference[:flatness]]
+Accurate vertical deblocking filter
+@table @option
+@item difference
+Difference factor where higher values mean more deblocking (default: @code{32}).
+@item flatness
+Flatness threshold where lower values mean more deblocking (default: @code{39}).
+@end table
+@end table
+
+The horizontal and vertical deblocking filters share the difference and
+flatness values so you cannot set different horizontal and vertical
+thresholds.
+
+@table @option
+@item h1/x1hdeblock
+Experimental horizontal deblocking filter
+
+@item v1/x1vdeblock
+Experimental vertical deblocking filter
+
+@item dr/dering
+Deringing filter
+
+@item tn/tmpnoise[:threshold1[:threshold2[:threshold3]]], temporal noise reducer
+@table @option
+@item threshold1
+larger -> stronger filtering
+@item threshold2
+larger -> stronger filtering
+@item threshold3
+larger -> stronger filtering
+@end table
+
+@item al/autolevels[:f/fullyrange], automatic brightness / contrast correction
+@table @option
+@item f/fullyrange
+Stretch luminance to @code{0-255}.
+@end table
+
+@item lb/linblenddeint
+Linear blend deinterlacing filter that deinterlaces the given block by
+filtering all lines with a @code{(1 2 1)} filter.
+
+@item li/linipoldeint
+Linear interpolating deinterlacing filter that deinterlaces the given block by
+linearly interpolating every second line.
+
+@item ci/cubicipoldeint
+Cubic interpolating deinterlacing filter deinterlaces the given block by
+cubically interpolating every second line.
+
+@item md/mediandeint
+Median deinterlacing filter that deinterlaces the given block by applying a
+median filter to every second line.
+
+@item fd/ffmpegdeint
+FFmpeg deinterlacing filter that deinterlaces the given block by filtering every
+second line with a @code{(-1 4 2 4 -1)} filter.
+
+@item l5/lowpass5
+Vertically applied FIR lowpass deinterlacing filter that deinterlaces the given
+block by filtering all lines with a @code{(-1 2 6 2 -1)} filter.
+
+@item fq/forceQuant[:quantizer]
+Overrides the quantizer table from the input with the constant quantizer you
+specify.
+@table @option
+@item quantizer
+Quantizer to use
+@end table
+
+@item de/default
+Default pp filter combination (@code{hb:a,vb:a,dr:a})
+
+@item fa/fast
+Fast pp filter combination (@code{h1:a,v1:a,dr:a})
+
+@item ac
+High quality pp filter combination (@code{ha:a:128:7,va:a,dr:a})
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Apply horizontal and vertical deblocking, deringing and automatic
+brightness/contrast:
+@example
+pp=hb/vb/dr/al
+@end example
+
+@item
+Apply default filters without brightness/contrast correction:
+@example
+pp=de/-al
+@end example
+
+@item
+Apply default filters and temporal denoiser:
+@example
+pp=default/tmpnoise:1:2:3
+@end example
+
+@item
+Apply deblocking on luminance only, and switch vertical deblocking on or off
+automatically depending on available CPU time:
+@example
+pp=hb:y/vb:a
+@end example
+@end itemize
+
 @section removelogo
 
 Suppress a TV station logo, using an image file to determine which