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, 12 insertions, 5 deletions

diff --git a/vp8/common/findnearmv.h b/vp8/common/findnearmv.h
index c142a0415..ffc02ed6c 100644
--- a/vp8/common/findnearmv.h
+++ b/vp8/common/findnearmv.h
@@ -125,8 +125,6 @@ static B_PREDICTION_MODE left_block_mode(const MODE_INFO *cur_mb, int b)
         --cur_mb;
         switch (cur_mb->mbmi.mode)
         {
-            case B_PRED:
-              return (cur_mb->bmi + b + 3)->as_mode;
             case DC_PRED:
                 return B_DC_PRED;
             case V_PRED:
@@ -135,6 +133,11 @@ static B_PREDICTION_MODE left_block_mode(const MODE_INFO *cur_mb, int b)
                 return B_HE_PRED;
             case TM_PRED:
                 return B_TM_PRED;
+#if CONFIG_I8X8
+            case I8X8_PRED:
+#endif
+            case B_PRED:
+              return (cur_mb->bmi + b + 3)->as_mode;
             default:
                 return B_DC_PRED;
         }
@@ -143,7 +146,8 @@ static B_PREDICTION_MODE left_block_mode(const MODE_INFO *cur_mb, int b)
     return (cur_mb->bmi + b - 1)->as_mode;
 }
 
-static B_PREDICTION_MODE above_block_mode(const MODE_INFO *cur_mb, int b, int mi_stride)
+static B_PREDICTION_MODE above_block_mode(const MODE_INFO
+                                          *cur_mb, int b, int mi_stride)
 {
     if (!(b >> 2))
     {
@@ -152,8 +156,6 @@ static B_PREDICTION_MODE above_block_mode(const MODE_INFO *cur_mb, int b, int mi
 
         switch (cur_mb->mbmi.mode)
         {
-            case B_PRED:
-              return (cur_mb->bmi + b + 12)->as_mode;
             case DC_PRED:
                 return B_DC_PRED;
             case V_PRED:
@@ -162,6 +164,11 @@ static B_PREDICTION_MODE above_block_mode(const MODE_INFO *cur_mb, int b, int mi
                 return B_HE_PRED;
             case TM_PRED:
                 return B_TM_PRED;
+#if CONFIG_I8X8
+            case I8X8_PRED:
+#endif
+            case B_PRED:
+              return (cur_mb->bmi + b + 12)->as_mode;
             default:
                 return B_DC_PRED;
         }