[x265] [PATCH] slicetype: increase baseline bframe bias by 10%

[Steve Borho]

# HG changeset patch
# User Steve Borho <steve at borho.org>
# Date 1379133436 18000
#      Fri Sep 13 23:37:16 2013 -0500
# Node ID 2555acbc97367b5ea2dcfd921b3ec577e9f5e4f0
# Parent  9c5a74cfacca9e0107c3d5d15521e2000d7bcdbc
slicetype: increase baseline bframe bias by 10%

Our estimateFrameCost() function is not yet checking bidir candidates (because
bidir search in the main encoder needs to be replaced first) and since B frame
estimates cannot use intra modes either this tends to make B frame scores
relatively higher than what x264 finds.  So our default bias needs to be a bit
higher in order for the lookahead to select B paths.

diff -r 9c5a74cfacca -r 2555acbc9736 source/encoder/slicetype.cpp
--- a/source/encoder/slicetype.cpp	Fri Sep 13 12:59:33 2013 -0500
+++ b/source/encoder/slicetype.cpp	Fri Sep 13 23:37:16 2013 -0500
@@ -313,7 +313,7 @@
         score = fenc->costEst[b - p0][p1 - b];
 
         if (b != p1)
-            score = (uint64_t)score * 100 / (120 + cfg->param.bFrameBias);
+            score = (uint64_t)score * 100 / (130 + cfg->param.bFrameBias);
 
         fenc->costEst[b - p0][p1 - b] = score;
     }