Add a description field to AVFilterContext.

Originally committed as revision 20354 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavfilter/avfilter.h

@@ -23,8 +23,8 @@
 #define AVFILTER_AVFILTER_H
 
 #define LIBAVFILTER_VERSION_MAJOR  1
-#define LIBAVFILTER_VERSION_MINOR  3
-#define LIBAVFILTER_VERSION_MICRO  1
+#define LIBAVFILTER_VERSION_MINOR  4
+#define LIBAVFILTER_VERSION_MICRO  0
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
                                                LIBAVFILTER_VERSION_MINOR, \
@@ -426,6 +426,12 @@ struct AVFilterContext
     AVFilterLink **outputs;         ///< array of pointers to output links
 
     void *priv;                     ///< private data for use by the filter
+
+    /**
+     * A description for the filter. You should use the
+     * NULL_IF_CONFIG_SMALL() macro to define it.
+     */
+    const char *description;
 };
 
 /**