commit fc83791043ba681cab6402e0a337722a95d9bcf1
author Peng Bin <binpengsmail@gmail.com> Thu Aug 23 16:34:35 2018 +0800
committer Yunqing Wang <yunqingwang@google.com> Mon Aug 27 20:13:24 2018 +0000
tree 6f25ce46145e37cb7f5430fbab7aea623a937090
parent 8443732a5e94645592d47bc6b6324697901ae55f

Refine init value of rate_correction_factors

rate_correction_factors used to map QP to bitrate.
As observed, the init value for the first alt ref
is always too large, which cause it re-encode
multiple times.

For encoder, about 2.6% faster shows by encoding 20 frame
of BasketballDrill_832x480_50.y4m target 800kbps.
( 265666 ms -> 258709 ms)

STATS_CHANGED

Change-Id: Ie2722adfc32b4a2d512fbff47cd59078c92599ce

av1/encoder/ratectrl.c

diff --git a/av1/encoder/ratectrl.c b/av1/encoder/ratectrl.c
index b00f9d9..0fc2f6f 100644
--- a/av1/encoder/ratectrl.c
+++ b/av1/encoder/ratectrl.c
@@ -302,9 +302,9 @@
   rc->avg_q = av1_convert_qindex_to_q(oxcf->worst_allowed_q, oxcf->bit_depth);
 
   for (i = 0; i < RATE_FACTOR_LEVELS; ++i) {
-    rc->rate_correction_factors[i] = 1.0;
+    rc->rate_correction_factors[i] = 0.7;
   }
-
+  rc->rate_correction_factors[KF_STD] = 1.0;
   rc->min_gf_interval = oxcf->min_gf_interval;
   rc->max_gf_interval = oxcf->max_gf_interval;
   if (rc->min_gf_interval == 0)