From: Jingning Han <jingning@google.com>
Date: Wed, 13 Jan 2016 17:03:15 +0000 (-0800)
Subject: Handle single ref mv pair in the candidate list for compound mode
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=3944cfb14db2ceb2836a718a2144e9edd7d3c54c;p=libvpx

Handle single ref mv pair in the candidate list for compound mode

This commit considers the case where a single reference motion
vector pair is found in the candidate list. It treats this pair
as the effective motion vector for nearestmv mode. This improves
the coding performance by 0.06% for stdhd sets.

Change-Id: I9ce12f456b52912933e05c18c3841a78c26155d2
---

diff --git a/vp10/decoder/decodemv.c b/vp10/decoder/decodemv.c
index 997c19e67..df0ec057b 100644
--- a/vp10/decoder/decodemv.c
+++ b/vp10/decoder/decodemv.c
@@ -886,6 +886,15 @@ static void read_inter_block_mode_info(VP10Decoder *const pbi,
       mbmi->mode != ZEROMV) {
     uint8_t ref_frame_type = vp10_ref_frame_type(mbmi->ref_frame);
 
+    if (xd->ref_mv_count[ref_frame_type] == 1 && mbmi->mode == NEARESTMV) {
+      int i;
+      nearestmv[0] = xd->ref_mv_stack[ref_frame_type][0].this_mv;
+      nearestmv[1] = xd->ref_mv_stack[ref_frame_type][0].comp_mv;
+
+      for (i = 0; i < MAX_MV_REF_CANDIDATES; ++i)
+        lower_mv_precision(&nearestmv[i].as_mv, allow_hp);
+    }
+
     if (xd->ref_mv_count[ref_frame_type] > 1) {
       int i;
       nearestmv[0] = xd->ref_mv_stack[ref_frame_type][0].this_mv;
diff --git a/vp10/encoder/rdopt.c b/vp10/encoder/rdopt.c
index f98382595..753bd8e7e 100644
--- a/vp10/encoder/rdopt.c
+++ b/vp10/encoder/rdopt.c
@@ -4464,7 +4464,7 @@ static int64_t handle_inter_mode(VP10_COMP *cpi, MACROBLOCK *x,
 #if CONFIG_REF_MV
   if (this_mode == NEARESTMV && is_comp_pred) {
     uint8_t ref_frame_type = vp10_ref_frame_type(mbmi->ref_frame);
-    if (mbmi_ext->ref_mv_count[ref_frame_type] > 1) {
+    if (mbmi_ext->ref_mv_count[ref_frame_type] > 0) {
       cur_mv[0] = mbmi_ext->ref_mv_stack[ref_frame_type][0].this_mv;
       cur_mv[1] = mbmi_ext->ref_mv_stack[ref_frame_type][0].comp_mv;
 
@@ -5684,39 +5684,37 @@ void vp10_rd_pick_inter_mode_sb(VP10_COMP *cpi,
         best_mbmode.mode = ZEROMV;
     } else {
       uint8_t rf_type = vp10_ref_frame_type(best_mbmode.ref_frame);
-      if (mbmi_ext->ref_mv_count[rf_type] > 1) {
-        int i;
-        int_mv nearestmv[2], nearmv[2];
-        const int allow_hp = cm->allow_high_precision_mv;
+      int i;
+      const int allow_hp = cm->allow_high_precision_mv;
+      int_mv nearestmv[2] = { frame_mv[NEARESTMV][refs[0]],
+                              frame_mv[NEARESTMV][refs[1]] };
+
+      int_mv nearmv[2] = { frame_mv[NEARMV][refs[0]],
+                           frame_mv[NEARMV][refs[1]] };
 
+      if (mbmi_ext->ref_mv_count[rf_type] >= 1) {
         nearestmv[0] = mbmi_ext->ref_mv_stack[rf_type][0].this_mv;
         nearestmv[1] = mbmi_ext->ref_mv_stack[rf_type][0].comp_mv;
+      }
+
+      if (mbmi_ext->ref_mv_count[rf_type] > 1) {
         nearmv[0] = mbmi_ext->ref_mv_stack[rf_type][1].this_mv;
         nearmv[1] = mbmi_ext->ref_mv_stack[rf_type][1].comp_mv;
+      }
 
-        for (i = 0; i < MAX_MV_REF_CANDIDATES; ++i) {
-          lower_mv_precision(&nearestmv[i].as_mv, allow_hp);
-          lower_mv_precision(&nearmv[i].as_mv, allow_hp);
-        }
-
-        if (nearestmv[0].as_int == best_mbmode.mv[0].as_int &&
-            nearestmv[1].as_int == best_mbmode.mv[1].as_int)
-          best_mbmode.mode = NEARESTMV;
-        else if (nearmv[0].as_int == best_mbmode.mv[0].as_int &&
-            nearmv[1].as_int == best_mbmode.mv[1].as_int)
-          best_mbmode.mode = NEARMV;
-        else if (best_mbmode.mv[0].as_int == 0 && best_mbmode.mv[1].as_int == 0)
-          best_mbmode.mode = ZEROMV;
-      } else {
-        if (frame_mv[NEARESTMV][refs[0]].as_int == best_mbmode.mv[0].as_int &&
-            (frame_mv[NEARESTMV][refs[1]].as_int == best_mbmode.mv[1].as_int))
-          best_mbmode.mode = NEARESTMV;
-        else if (frame_mv[NEARMV][refs[0]].as_int == best_mbmode.mv[0].as_int &&
-            (frame_mv[NEARMV][refs[1]].as_int == best_mbmode.mv[1].as_int))
-          best_mbmode.mode = NEARMV;
-        else if (best_mbmode.mv[0].as_int == 0 && best_mbmode.mv[1].as_int == 0)
-          best_mbmode.mode = ZEROMV;
+      for (i = 0; i < MAX_MV_REF_CANDIDATES; ++i) {
+        lower_mv_precision(&nearestmv[i].as_mv, allow_hp);
+        lower_mv_precision(&nearmv[i].as_mv, allow_hp);
       }
+
+      if (nearestmv[0].as_int == best_mbmode.mv[0].as_int &&
+          nearestmv[1].as_int == best_mbmode.mv[1].as_int)
+        best_mbmode.mode = NEARESTMV;
+      else if (nearmv[0].as_int == best_mbmode.mv[0].as_int &&
+          nearmv[1].as_int == best_mbmode.mv[1].as_int)
+        best_mbmode.mode = NEARMV;
+      else if (best_mbmode.mv[0].as_int == 0 && best_mbmode.mv[1].as_int == 0)
+        best_mbmode.mode = ZEROMV;
     }
 #else
     if (frame_mv[NEARESTMV][refs[0]].as_int == best_mbmode.mv[0].as_int &&