avfilter: add removegrain

Signed-off-by: Paul B Mahol <onemda@gmail.com>

Changelog

@@ -13,6 +13,7 @@ version <next>:
 - Many improvements to the JPEG 2000 decoder
 - Go2Meeting decoding support
 - adrawgraph audio and drawgraph video filter
+- removegrain video filter
 
 
 version 2.7:

doc/filters.texi

@@ -8005,6 +8005,110 @@ qp=2+2*sin(PI*qp)
 @end example
 @end itemize
 
+@section removegrain
+
+The removegrain filter is a spatial denoiser for progressive video.
+
+@table @option
+@item m0
+Set mode for the first plane.
+
+@item m1
+Set mode for the second plane.
+
+@item m2
+Set mode for the third plane.
+
+@item m3
+Set mode for the fourth plane.
+@end table
+
+Range of mode is from 0 to 24. Description of each mode follows:
+
+@table @var
+@item 0
+Leave input plane unchanged. Default.
+
+@item 1
+Clips the pixel with the minimum and maximum of the 8 neighbour pixels.
+
+@item 2
+Clips the pixel with the second minimum and maximum of the 8 neighbour pixels.
+
+@item 3
+Clips the pixel with the third minimum and maximum of the 8 neighbour pixels.
+
+@item 4
+Clips the pixel with the fourth minimum and maximum of the 8 neighbour pixels.
+This is equivalent to a median filter.
+
+@item 5
+Line-sensitive clipping giving the minimal change.
+
+@item 6
+Line-sensitive clipping, intermediate.
+
+@item 7
+Line-sensitive clipping, intermediate.
+
+@item 8
+Line-sensitive clipping, intermediate.
+
+@item 9
+Line-sensitive clipping on a line where the neighbours pixels are the closest.
+
+@item 10
+Replaces the target pixel with the closest neighbour.
+
+@item 11
+[1 2 1] horizontal and vertical kernel blur.
+
+@item 12
+Same as mode 11.
+
+@item 13
+Bob mode, interpolates top field from the line where the neighbours
+pixels are the closest.
+
+@item 14
+Bob mode, interpolates bottom field from the line where the neighbours
+pixels are the closest.
+
+@item 15
+Bob mode, interpolates top field. Same as 13 but with a more complicated
+interpolation formula.
+
+@item 16
+Bob mode, interpolates bottom field. Same as 14 but with a more complicated
+interpolation formula.
+
+@item 17
+Clips the pixel with the minimum and maximum of respectively the maximum and
+minimum of each pair of opposite neighbour pixels.
+
+@item 18
+Line-sensitive clipping using opposite neighbours whose greatest distance from
+the current pixel is minimal.
+
+@item 19
+Replaces the pixel with the average of its 8 neighbours.
+
+@item 20
+Averages the 9 pixels ([1 1 1] horizontal and vertical blur).
+
+@item 21
+Clips pixels using the averages of opposite neighbour.
+
+@item 22
+Same as mode 21 but simpler and faster.
+
+@item 23
+Small edge and halo removal, but reputed useless.
+
+@item 24
+Similar as 23.
+@end table
+
 @section removelogo
 
 Suppress a TV station logo, using an image file to determine which

libavfilter/Makefile

@@ -178,6 +178,7 @@ OBJS-$(CONFIG_PP7_FILTER)                    += vf_pp7.o
 OBJS-$(CONFIG_PSNR_FILTER)                   += vf_psnr.o dualinput.o framesync.o
 OBJS-$(CONFIG_PULLUP_FILTER)                 += vf_pullup.o
 OBJS-$(CONFIG_QP_FILTER)                     += vf_qp.o
+OBJS-$(CONFIG_REMOVEGRAIN_FILTER)            += vf_removegrain.o
 OBJS-$(CONFIG_REMOVELOGO_FILTER)             += bbox.o lswsutils.o lavfutils.o vf_removelogo.o
 OBJS-$(CONFIG_REPEATFIELDS_FILTER)           += vf_repeatfields.o
 OBJS-$(CONFIG_ROTATE_FILTER)                 += vf_rotate.o

libavfilter/allfilters.c

@@ -193,6 +193,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(PSNR,           psnr,           vf);
     REGISTER_FILTER(PULLUP,         pullup,         vf);
     REGISTER_FILTER(QP,             qp,             vf);
+    REGISTER_FILTER(REMOVEGRAIN,    removegrain,    vf);
     REGISTER_FILTER(REMOVELOGO,     removelogo,     vf);
     REGISTER_FILTER(REPEATFIELDS,   repeatfields,   vf);
     REGISTER_FILTER(ROTATE,         rotate,         vf);

libavfilter/version.h

@@ -30,7 +30,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  5
-#define LIBAVFILTER_VERSION_MINOR  20
+#define LIBAVFILTER_VERSION_MINOR  21
 #define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \