add 8x8 intra prediction modes

Patch 1 to Patch 3 is an initial implementation of 8x8 intra prediction
modes, here are with the following assumptions:
a. 8x8 has 4 prediction modes DC, H, V and TM
b. UV 4x4 block use the same mode as corresponding 8x8 area
c. i8x8 modes are enabled for key frame only for now
Patch 4:
d. removed debug code from previous patches
Patch 5:
e. added stats code to collect entropy stats and further cleaned up
Patch 6:
f. changed mode stats code to collect finer stats of modes
Patch 7:
g. normalized i8x8 modes distribution to total at 256 (8bits).
Patch 8:
h. fixed a bug in decoder and removed debug printf output.
Patch 9:
i. more cleanups to address paul's comment
Patch 10:
j. messy rebase/merges to bring the commit up to date.

Tests on HD clips encoded with all key frame showing consistent gain
on all clips and all metrics:~0.5%(psnr) and 0.6%(ssim):
http://www.corp.google.com/~yaowu/no_crawl/i8x8hd_allkey_fixedq.html

To build and test, configure with:
--enable-experimental --enable-i8x8

Change-Id: I9813fe07ae48cab5fdb5d904bca022514ad01e7f

1 files changed, 6 insertions, 0 deletions

diff --git a/vp8/encoder/modecosts.c b/vp8/encoder/modecosts.c
index c636c482b..892fe9f71 100644
--- a/vp8/encoder/modecosts.c
+++ b/vp8/encoder/modecosts.c
@@ -44,4 +44,10 @@ void vp8_init_mode_costs(VP8_COMP *c)
 
     vp8_cost_tokens(c->mb.intra_uv_mode_cost[1], x->fc.uv_mode_prob, vp8_uv_mode_tree);
     vp8_cost_tokens(c->mb.intra_uv_mode_cost[0], x->kf_uv_mode_prob, vp8_uv_mode_tree);
+#if CONFIG_I8X8
+    vp8_cost_tokens(c->mb.i8x8_mode_costs,
+                    x->i8x8_mode_prob,vp8_i8x8_mode_tree);
+#endif
+
+
 }