Add erode libopencv filter.

Originally committed as revision 26097 to svn://svn.ffmpeg.org/ffmpeg/trunk

doc/filters.texi

@@ -532,6 +532,7 @@ informations:
 
 Follows the list of supported libopencv filters.
 
+@anchor{dilate}
 @subsection dilate
 
 Dilate an image by using a specific structuring element.
@@ -578,6 +579,15 @@ ocv=dilate=5x5+2x2/cross:2
 ocv=0x0+2x2/custom=diamond.shape:2
 @end example
 
+@subsection erode
+
+Erode an image by using a specific structuring element.
+This filter corresponds to the libopencv function @code{cvErode}.
+
+The filter accepts the parameters: @var{struct_el}:@var{nb_iterations},
+with the same meaning and use of those of the dilate filter
+(@pxref{dilate}).
+
 @subsection smooth
 
 Smooth the input video.

libavfilter/avfilter.h

@@ -28,7 +28,7 @@
 
 #define LIBAVFILTER_VERSION_MAJOR  1
 #define LIBAVFILTER_VERSION_MINOR 70
-#define LIBAVFILTER_VERSION_MICRO  1
+#define LIBAVFILTER_VERSION_MICRO  2
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
                                                LIBAVFILTER_VERSION_MINOR, \

libavfilter/vf_libopencv.c

@@ -291,6 +291,13 @@ static void dilate_end_frame_filter(AVFilterContext *ctx, IplImage *inimg, IplIm
     cvDilate(inimg, outimg, dilate->kernel, dilate->nb_iterations);
 }
 
+static void erode_end_frame_filter(AVFilterContext *ctx, IplImage *inimg, IplImage *outimg)
+{
+    OCVContext *ocv = ctx->priv;
+    DilateContext *dilate = ocv->priv;
+    cvErode(inimg, outimg, dilate->kernel, dilate->nb_iterations);
+}
+
 typedef struct {
     const char *name;
     size_t priv_size;
@@ -301,6 +308,7 @@ typedef struct {
 
 static OCVFilterEntry ocv_filter_entries[] = {
     { "dilate", sizeof(DilateContext), dilate_init, dilate_uninit, dilate_end_frame_filter },
+    { "erode",  sizeof(DilateContext), dilate_init, dilate_uninit, erode_end_frame_filter  },
     { "smooth", sizeof(SmoothContext), smooth_init, NULL, smooth_end_frame_filter },
 };