From b7050c0be34c8a9f8a4c2a249b676bc5cd23e834 Mon Sep 17 00:00:00 2001
From: Jingning Han <jingning@google.com>
Date: Mon, 23 Feb 2015 12:33:24 -0800
Subject: [PATCH] Motion compensated reference refinement

This commit applies one-step refinement search to the resulting
motion vector of the integral projectiion based motion estimation,
per 64x64 block. It improves the coding performance of speed -6.

pedestrian 1080p 500 kbps
51735 b/f, 36.794 dB, 16044 ms ->
51382 b/f, 36.793 dB, 16282 ms

cloud 1080p 500 kbps
24081 b/f, 37.988 dB, 14016 ms ->
23597 b/f, 38.076 dB, 12774 ms

vidyo1 720p 1000 kbps
16552 b/f, 40.514 dB, 8279 ms ->
16553 b/f, 40.543 dB, 8510 ms

The rtc set compression performance is improved by 0.5%.

Change-Id: I3d09bea2caf58b2a4f3b38aa26fffafcbe9a2c17
---
 vp9/encoder/vp9_encodeframe.c | 30 ++++++++++++++++++++++++++++--
 1 file changed, 28 insertions(+), 2 deletions(-)

diff --git a/vp9/encoder/vp9_encodeframe.c b/vp9/encoder/vp9_encodeframe.c
index 39dedf6cb..3bdaa043f 100644
--- a/vp9/encoder/vp9_encodeframe.c
+++ b/vp9/encoder/vp9_encodeframe.c
@@ -569,7 +569,12 @@ static int vector_match(int16_t *ref, int16_t *src) {
   return (center - 32);
 }
 
-static void motion_estimation(MACROBLOCK *x) {
+static const MV search_pos[9] = {
+  {-1, -1}, {-1, 0}, {-1, 1}, {0, -1}, {0, 0}, {0, 1},
+  {1, -1}, {1, 0}, {1, 1},
+};
+
+static void motion_estimation(VP9_COMP *cpi, MACROBLOCK *x) {
   MACROBLOCKD *xd = &x->e_mbd;
   DECLARE_ALIGNED(16, int16_t, hbuf[128]);
   DECLARE_ALIGNED(16, int16_t, vbuf[128]);
@@ -583,6 +588,8 @@ static void motion_estimation(MACROBLOCK *x) {
   const int ref_stride = xd->plane[0].pre[0].stride;
   uint8_t const *ref_buf, *src_buf;
   MV *tmp_mv = &xd->mi[0].src_mi->mbmi.mv[0].as_mv;
+  int best_sad;
+  MV this_mv;
 
   // Set up prediction 1-D reference set
   ref_buf = xd->plane[0].pre[0].buf + (-32);
@@ -614,6 +621,24 @@ static void motion_estimation(MACROBLOCK *x) {
   tmp_mv->col = vector_match(hbuf, src_hbuf);
   tmp_mv->row = vector_match(vbuf, src_vbuf);
 
+  best_sad = INT_MAX;
+  this_mv = *tmp_mv;
+  for (idx = 0; idx < 9; ++idx) {
+    int this_sad;
+    src_buf = x->plane[0].src.buf;
+    ref_buf = xd->plane[0].pre[0].buf +
+        (search_pos[idx].row + this_mv.row) * ref_stride +
+        (search_pos[idx].col + this_mv.col);
+
+    this_sad = cpi->fn_ptr[BLOCK_64X64].sdf(src_buf, src_stride,
+                                            ref_buf, ref_stride);
+    if (this_sad < best_sad) {
+      best_sad = this_sad;
+      tmp_mv->row = search_pos[idx].row + this_mv.row;
+      tmp_mv->col = search_pos[idx].col + this_mv.col;
+    }
+  }
+
   tmp_mv->row *= 8;
   tmp_mv->col *= 8;
 
@@ -664,9 +689,10 @@ static void choose_partitioning(VP9_COMP *cpi,
     mbmi->ref_frame[1] = NONE;
     mbmi->sb_type = BLOCK_64X64;
     mbmi->mv[0].as_int = 0;
+    mbmi->interp_filter = BILINEAR;
 
 #if GLOBAL_MOTION
-    motion_estimation(x);
+    motion_estimation(cpi, x);
 #endif
 
     vp9_build_inter_predictors_sb(xd, mi_row, mi_col, BLOCK_64X64);