From c4a5ef1ced7c318fb1bcb361f670e776b277996a Mon Sep 17 00:00:00 2001
From: Peter de Rivaz <peter.derivaz@gmail.com>
Date: Mon, 12 May 2014 11:54:09 +0100
Subject: [PATCH] Added rounding to highbitdepth subtraction

This improves encoding performance for high
bitrate sequences when using 10 or 12bit.

Change-Id: I358d30a69251d58589c075b7d52c0d9ae76b26ee
---
 vp9/encoder/vp9_encodemb.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/vp9/encoder/vp9_encodemb.c b/vp9/encoder/vp9_encodemb.c
index 7ebf7fb0d..3494e0d25 100644
--- a/vp9/encoder/vp9_encodemb.c
+++ b/vp9/encoder/vp9_encodemb.c
@@ -61,9 +61,13 @@ void vp9_high_subtract_block_c(int rows, int cols,
   int shift = bps - 8;
   uint16_t *src = CONVERT_TO_SHORTPTR(src8);
   uint16_t *pred = CONVERT_TO_SHORTPTR(pred8);
+  int rnd = 0;
+  if (shift >= 1) {
+    rnd = 1 << (shift - 1);
+  }
   for (r = 0; r < rows; r++) {
     for (c = 0; c < cols; c++) {
-      diff[c] = ((int)src[c] - (int)pred[c]) >> shift;
+      diff[c] = ((int)src[c] - (int)pred[c] + rnd) >> shift;
     }
 
     diff += diff_stride;