commit 75ce8ba80b6cde9bf58f406157d3b87feece9fda
author Hui Su <huisu@google.com> Wed Sep 25 16:46:14 2019 -0700
committer Hui Su <huisu@google.com> Tue Oct 01 16:40:23 2019 +0000
tree 4efc4af7935bbe5989520623363414c7744b5b85
parent 6e61c8e4be2d49a74a0d45450f1075bdc88d5698

Change the reference frame priority order

The new order is based on reference frame selection frequency calculated
from encoding stats. This only affects the first several frames in a KF
group. On lowres, there is 0.2% compression gains when encoding 16
frames(speed 1).

STATS_CHANGED

Change-Id: I7b83e91a34e9e79771361b7e8f082da9e4712f8f

av1/encoder/encode_strategy.c

diff --git a/av1/encoder/encode_strategy.c b/av1/encoder/encode_strategy.c
index 27ce6c4..156cf11 100644
--- a/av1/encoder/encode_strategy.c
+++ b/av1/encoder/encode_strategy.c
@@ -213,8 +213,8 @@
 static int get_ref_frame_flags(const AV1_COMP *const cpi) {
   static const MV_REFERENCE_FRAME
       ref_frame_priority_order[INTER_REFS_PER_FRAME] = {
-        LAST_FRAME,   ALTREF_FRAME, LAST2_FRAME,   LAST3_FRAME,
-        GOLDEN_FRAME, BWDREF_FRAME, ALTREF2_FRAME,
+        LAST_FRAME,    ALTREF_FRAME, BWDREF_FRAME, GOLDEN_FRAME,
+        ALTREF2_FRAME, LAST2_FRAME,  LAST3_FRAME,
       };
   const AV1_COMMON *const cm = &cpi->common;
   const RefCntBuffer *ref_frames[INTER_REFS_PER_FRAME];