commit 12dc7f79600ad6855b6caef88be69eb6f969fe20
author Jingning Han <jingning@google.com> Thu Feb 25 13:49:53 2021 -0800
committer Jingning Han <jingning@google.com> Mon Mar 01 19:30:42 2021 +0000
tree f90d1f1fe12930d8cca511bef5a7675035428976
parent b2228d30f72b54a8bcb1f3e391dcf28f23f8aa9c

Scale 4x4 Hadamard transform

Lower the dynamic range in HDR setting.

Temporary solution for
BUG=aomedia:2973

Follow up work will re-design Hadamard transforms
for later experiments.

STATS_CHANGED

Change-Id: Ia87954851017ef233e34ccbf884215ad7ebc4285

aom_dsp/avg.c

diff --git a/aom_dsp/avg.c b/aom_dsp/avg.c
index 0ec21fb..b88d48c 100644
--- a/aom_dsp/avg.c
+++ b/aom_dsp/avg.c
@@ -90,10 +90,10 @@
 
 static void hadamard_col4(const int16_t *src_diff, ptrdiff_t src_stride,
                           int16_t *coeff) {
-  int16_t b0 = src_diff[0 * src_stride] + src_diff[1 * src_stride];
-  int16_t b1 = src_diff[0 * src_stride] - src_diff[1 * src_stride];
-  int16_t b2 = src_diff[2 * src_stride] + src_diff[3 * src_stride];
-  int16_t b3 = src_diff[2 * src_stride] - src_diff[3 * src_stride];
+  int16_t b0 = (src_diff[0 * src_stride] + src_diff[1 * src_stride]) >> 1;
+  int16_t b1 = (src_diff[0 * src_stride] - src_diff[1 * src_stride]) >> 1;
+  int16_t b2 = (src_diff[2 * src_stride] + src_diff[3 * src_stride]) >> 1;
+  int16_t b3 = (src_diff[2 * src_stride] - src_diff[3 * src_stride]) >> 1;
 
   coeff[0] = b0 + b2;
   coeff[1] = b1 + b3;