Make the validity checks fail only if the corresponding luma or chroma

values are not zero.
Prevent aborting with the default values.

Originally committed as revision 25471 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavfilter/vf_unsharp.c

@@ -133,7 +133,8 @@ static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
         sscanf(args, "%d:%d:%lf:%d:%d:%lf", &lmsize_x, &lmsize_y, &lamount,
                                             &cmsize_x, &cmsize_y, &camount);
 
-    if (lmsize_x < 2 || lmsize_y < 2 || cmsize_x < 2 || cmsize_y < 2) {
+    if ((lamount && (lmsize_x < 2 || lmsize_y < 2)) ||
+        (camount && (cmsize_x < 2 || cmsize_y < 2))) {
         av_log(ctx, AV_LOG_ERROR,
                "Invalid value <2 for lmsize_x:%d or lmsize_y:%d or cmsize_x:%d or cmsize_y:%d\n",
                lmsize_x, lmsize_y, cmsize_x, cmsize_y);