Attempt to fix an issue related to 8x8 transform and segfeature

logically this commit should NOT change anything, but seems to help
revert the 3DB loss on bowing in the following commit:

https://on2-git.corp.google.com/g/#change,6193

This is still debugging in progress. Need further investigation to
understand the root cause of the issue.

Change-Id: I0b49d1ef3a311dfff58c6acd3eaebdb3bda6257c

diff --git a/vp8/common/idctllm.c b/vp8/common/idctllm.c
index a0042ae6d257005d0fe71ddc90cc885cbdbede26..ba4beb4ca6612ce23d95d3b4562b8e7642782aed 100644 (file)
--- a/vp8/common/idctllm.c
+++ b/vp8/common/idctllm.c
@@ -399,14 +399,14 @@ static void idctcol (int *blk)
   x4 = (181 * (x4 - x5) + 128) >> 8;
 
   /* fourth stage */
-  blk[8 * 0] = (x7 + x1 ) >> 15;
-  blk[8 * 1] = (x3 + x2 ) >> 15;
-  blk[8 * 2] = (x0 + x4 ) >> 15;
-  blk[8 * 3] = (x8 + x6 ) >> 15;
-  blk[8 * 4] = (x8 - x6 ) >> 15;
-  blk[8 * 5] = (x0 - x4 ) >> 15;
-  blk[8 * 6] = (x3 - x2 ) >> 15;
-  blk[8 * 7] = (x7 - x1 ) >> 15;
+  blk[8 * 0] = (x7 + x1 ) >> 14;
+  blk[8 * 1] = (x3 + x2 ) >> 14;
+  blk[8 * 2] = (x0 + x4 ) >> 14;
+  blk[8 * 3] = (x8 + x6 ) >> 14;
+  blk[8 * 4] = (x8 - x6 ) >> 14;
+  blk[8 * 5] = (x0 - x4 ) >> 14;
+  blk[8 * 6] = (x3 - x2 ) >> 14;
+  blk[8 * 7] = (x7 - x1 ) >> 14;
 }
 
 #define TX_DIM 8
@@ -434,7 +434,7 @@ void vp8_short_idct8x8_c(short *coefs, short *block, int pitch)
     {
         for (j = 0; j < TX_DIM; j++)
         {
-             block[i*shortpitch+j]  = X[i * TX_DIM + j];
+             block[i*shortpitch+j]  = X[i * TX_DIM + j]>>1;
         }
     }
 }