avfilter: add selectivecolor filter

Changelog

@@ -17,6 +17,7 @@ version <next>:
 - chromaprint fingerprinting muxer
 - ffplay dynamic volume control
 - displace filter
+- selectivecolor filter
 
 
 version 2.8:

doc/filters.texi

@@ -13037,6 +13037,73 @@ select=n=2:e='mod(n, 2)+1' [odd][even]; [odd] pad=h=2*ih [tmp]; [tmp][even] over
 @end example
 @end itemize
 
+@section selectivecolor
+
+Adjust cyan, magenta, yellow and black (CMYK) to certain ranges of colors (such
+as "reds", "yellows", "greens", "cyans", ...). The adjustment range is defined
+by the "purity" of the color (that is, how saturated it already is).
+
+This filter is similar to the Adobe Photoshop Selective Color tool.
+
+The filter accepts the following options:
+
+@table @option
+@item correction_method
+Select color correction method.
+
+Available values are:
+@table @samp
+@item absolute
+Specified adjustments are applied "as-is" (added/subtracted to original pixel
+component value).
+@item relative
+Specified adjustments are relative to the original component value.
+@end table
+Default is @code{absolute}.
+@item reds
+Adjustments for red pixels (pixels where the red component is the maximum)
+@item yellows
+Adjustments for yellow pixels (pixels where the blue component is the minimum)
+@item greens
+Adjustments for green pixels (pixels where the green component is the maximum)
+@item cyans
+Adjustments for cyan pixels (pixels where the red component is the minimum)
+@item blues
+Adjustments for blue pixels (pixels where the blue component is the maximum)
+@item magentas
+Adjustments for magenta pixels (pixels where the green component is the minimum)
+@item whites
+Adjustments for white pixels (pixels where all components are greater than 128)
+@item neutrals
+Adjustments for all pixels except pure black and pure white
+@item blacks
+Adjustments for black pixels (pixels where all components are lesser than 128)
+@item psfile
+Specify a Photoshop selective color file (@code{.asv}) to import the settings from.
+@end table
+
+All the adjustment settings (@option{reds}, @option{yellows}, ...) accept up to
+4 space separated floating point adjustment values in the [-1,1] range,
+respectively to adjust the amount of cyan, magenta, yellow and black for the
+pixels of its range.
+
+@subsection Examples
+
+@itemize
+@item
+Increase cyan by 55% and reduce yellow by 33% in every green areas, and
+increase magenta by 27% in blue areas:
+@example
+selectivecolor=greens=.5 0 -.33 0:blues=0 .27
+@end example
+
+@item
+Use a Photoshop selective color preset:
+@example
+selectivecolor=psfile=MySelectiveColorPresets/Misty.asv
+@end example
+@end itemize
+
 @section sendcmd, asendcmd
 
 Send commands to filters in the filtergraph.

libavfilter/Makefile

@@ -206,6 +206,7 @@ OBJS-$(CONFIG_SAB_FILTER)                    += vf_sab.o
 OBJS-$(CONFIG_SCALE_FILTER)                  += vf_scale.o
 OBJS-$(CONFIG_SCALE2REF_FILTER)              += vf_scale.o
 OBJS-$(CONFIG_SELECT_FILTER)                 += f_select.o
+OBJS-$(CONFIG_SELECTIVECOLOR_FILTER)         += vf_selectivecolor.o
 OBJS-$(CONFIG_SENDCMD_FILTER)                += f_sendcmd.o
 OBJS-$(CONFIG_SETDAR_FILTER)                 += vf_aspect.o
 OBJS-$(CONFIG_SETFIELD_FILTER)               += vf_setfield.o

libavfilter/allfilters.c

@@ -226,6 +226,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(SCALE,          scale,          vf);
     REGISTER_FILTER(SCALE2REF,      scale2ref,      vf);
     REGISTER_FILTER(SELECT,         select,         vf);
+    REGISTER_FILTER(SELECTIVECOLOR, selectivecolor, vf);
     REGISTER_FILTER(SENDCMD,        sendcmd,        vf);
     REGISTER_FILTER(SEPARATEFIELDS, separatefields, vf);
     REGISTER_FILTER(SETDAR,         setdar,         vf);

libavfilter/version.h

@@ -30,7 +30,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVFILTER_VERSION_MAJOR   6
-#define LIBAVFILTER_VERSION_MINOR  10
+#define LIBAVFILTER_VERSION_MINOR  11
 #define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \