Supporting high precision 1/8-pel motion vectors

This is the initial patch for supporting 1/8th pel
motion. Currently if we configure with enable-high-precision-mv,
all motion vectors would default to 1/8 pel. Encode and
decode syncs fine with the current code. In the next phase
the code will be refactored so that we can choose the 1/8
pel mode adaptively at a frame/segment/mb level.

Derf results:
http://www.corp.google.com/~debargha/vp8_results/enhinterp_hpmv.html
(about 0.83% better than 8-tap interpoaltion)

Patch 3: Rebased. Also adding 1/16th pel interpolation for U and V

Patch 4: HD results.
http://www.corp.google.com/~debargha/vp8_results/enhinterp_hd_hpmv.html
Seems impressive (unless I am doing something wrong).

Patch 5: Added mmx/sse for bilateral filtering, as well as enforced
use of c-versions of subpel filters with 8-taps and 1/16th pel;
Also redesigned the 8-tap filters to reduce the cut-off in order to
introduce a denoising effect. There is a new configure option
sixteenth-subpel-uv which will use 1/16 th pel interpolation for
uv, if the motion vectors have 1/8 pel accuracy.

With the fixes the results are promising on the derf set. The enhanced
interpolation option with 8-taps alone gives 3% improvement over thei
derf set:
http://www.corp.google.com/~debargha/vp8_results/enhinterpn.html

Results on high precision mv and on the hd set are to follow.

Patch 6: Adding a missing condition for CONFIG_SIXTEENTH_SUBPEL_UV in
vp8/common/x86/x86_systemdependent.c

Patch 7: Cleaning up various debug messages.

Patch 8: Merge conflict

Change-Id: I5b1d844457aefd7414a9e4e0e06c6ed38fd8cc04

1 files changed, 25 insertions, 2 deletions

diff --git a/vp8/common/entropymode.c b/vp8/common/entropymode.c
index cdc510acf..540da33ed 100644
--- a/vp8/common/entropymode.c
+++ b/vp8/common/entropymode.c
@@ -225,6 +225,28 @@ struct vp8_token_struct vp8_mbsplit_encodings [VP8_NUMMBSPLITS];
 struct vp8_token_struct vp8_mv_ref_encoding_array    [VP8_MVREFS];
 struct vp8_token_struct vp8_sub_mv_ref_encoding_array [VP8_SUBMVREFS];
 
+#if CONFIG_HIGH_PRECISION_MV
+const vp8_tree_index vp8_small_mvtree [30] =
+{
+     2,  16,
+     4,  10,
+     6,   8,
+    -0,  -1,
+    -2,  -3,
+    12,  14,
+    -4,  -5,
+    -6,  -7,
+    18,  24,
+    20,  22,
+    -8,  -9,
+   -10, -11,
+    26,  28,
+   -12, -13,
+   -14, -15
+};
+struct vp8_token_struct vp8_small_mvencodings [16];
+
+#else
 
 const vp8_tree_index vp8_small_mvtree [14] =
 {
@@ -236,9 +258,11 @@ const vp8_tree_index vp8_small_mvtree [14] =
     -4, -5,
     -6, -7
 };
-
 struct vp8_token_struct vp8_small_mvencodings [8];
 
+#endif  /* CONFIG_HIGH_PRECISION_MV */
+
+
 void vp8_init_mbmode_probs(VP8_COMMON *x)
 {
     unsigned int bct [VP8_YMODES] [2];      /* num Ymodes > num UV modes */
@@ -489,4 +513,3 @@ void print_mv_ref_cts(VP8_COMMON *pc)
         printf("\n");
     }
 }
-