add a comment for the previous commit

git-svn-id: https://mpc-hc.svn.sourceforge.net/svnroot/mpc-hc/trunk@3912 10f7b99b-c216-0410-bff0-8a66a9350fd8

src/filters/transform/MPCVideoDec/FfmpegContext.c

@@ -825,7 +825,7 @@ BOOL DXVACheckFramesize(int width, int height, DWORD nPCIVendor/*, DWORD nPCIDev
 		}
 	} else if (nPCIVendor == PCIV_ATI) {
 		if (width <= 2048 && height <= 2048) { // tested H.264 on UVD 2.2 (HD5770, HD5850)
-			return TRUE;
+			return TRUE; //it may also work if (width <= 2064 && height <= 2064 && width*height <= 2088960), but unstable
 		}
 	} else if (width <= 1920 && height <= 1088) {
 		return TRUE;