swscale/swscale_unscaled: fix ya16 input

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libswscale/swscale_unscaled.c

@@ -1730,7 +1730,7 @@ void ff_get_unscaled_swscale(SwsContext *c)
     if (srcFormat == AV_PIX_FMT_UYVY422 && dstFormat == AV_PIX_FMT_YUV422P)
         c->swscale = uyvyToYuv422Wrapper;
 
-#define isPlanarGray(x) (isGray(x) && (x) != AV_PIX_FMT_YA8)
+#define isPlanarGray(x) (isGray(x) && (x) != AV_PIX_FMT_YA8 && (x) != AV_PIX_FMT_YA16LE && (x) != AV_PIX_FMT_YA16BE)
     /* simple copy */
     if ( srcFormat == dstFormat ||
         (srcFormat == AV_PIX_FMT_YUVA420P && dstFormat == AV_PIX_FMT_YUV420P) ||