fix a small bug in 16 point forward dct

The commit fixes a minor error in 16 point fdct where in a rotation can
produce result of -1 instead of 0.

Change-Id: I45aac4a52bcd06225c6d04e643547a13e1c1aade

diff --git a/vp9/encoder/vp9_dct.c b/vp9/encoder/vp9_dct.c
index bfde02ccbe841d4efa591965c4fcebe302c141f6..32e7b3fbc4cdfc8a5b3cb58ac646c7c5515d8c77 100644 (file)
--- a/vp9/encoder/vp9_dct.c
+++ b/vp9/encoder/vp9_dct.c
@@ -1288,7 +1288,7 @@ static void dct16x16_1d(int16_t input[16], int16_t output[16],
 
     output[15] = (intermediate[11] + intermediate[12] + output_rounding)
         >> output_shift;
-    output[ 1] = -(intermediate[11] - intermediate[12] + output_rounding)
+    output[ 1] = (intermediate[12] - intermediate[11] + output_rounding)
         >> output_shift;
 
     output[ 7] = (2 * (intermediate[13] * C8) + final_rounding) >> final_shift;