commit 7f99477a7e7096617b7415cd9b4da30af0e29923
author Jingning Han <jingning@google.com> Thu Jul 27 08:02:16 2017 -0700
committer Jingning Han <jingning@google.com> Mon Aug 07 22:34:31 2017 +0000
tree 621601e308a040304471dc163ed0cf5e37b274ec
parent 50b0f6ca1cf758b45f1398e3980eb6cff5f78bfc

Use 8x8 block mv search for sub8x8 blocks

Use 8x8 block search resolution for reference motion vectors for
non-nearest neighbors of a sub8x8 coding block. The compression
performance is slightly up by 0.05%.

Change-Id: I83d99a2232b0bb92f87dd22a77a4005ce0c0c883

av1/common/mvref_common.c

diff --git a/av1/common/mvref_common.c b/av1/common/mvref_common.c
index 88c762a..b85cbb8 100644
--- a/av1/common/mvref_common.c
+++ b/av1/common/mvref_common.c
@@ -159,17 +159,24 @@
   const TileInfo *const tile = &xd->tile;
   int i;
   uint8_t newmv_count = 0;
+  int col_offset = 0;
 #if CONFIG_CB4X4
   const int bsize = xd->mi[0]->mbmi.sb_type;
-  const int mi_offset =
-      bsize < BLOCK_8X8 ? mi_size_wide[BLOCK_4X4] : mi_size_wide[BLOCK_8X8];
+  const int mi_offset = bsize < BLOCK_8X8 || abs(row_offset) > 1
+                            ? mi_size_wide[BLOCK_4X4]
+                            : mi_size_wide[BLOCK_8X8];
   // TODO(jingning): Revisit this part after cb4x4 is stable.
-  if (bsize >= BLOCK_8X8) row_offset *= 2;
+  if (bsize >= BLOCK_8X8 || abs(row_offset) > 1) row_offset *= 2;
+
+  if (bsize < BLOCK_8X8 && abs(row_offset) > 1) {
+    if (mi_row & 0x01) row_offset += 1;
+    if (mi_col & 0x01) col_offset -= 1;
+  }
 #else
   const int mi_offset = mi_size_wide[BLOCK_8X8];
 #endif
 
-  for (i = 0; i < xd->n8_w && *refmv_count < MAX_REF_MV_STACK_SIZE;) {
+  for (i = col_offset; i < xd->n8_w && *refmv_count < MAX_REF_MV_STACK_SIZE;) {
     POSITION mi_pos;
 #if CONFIG_CB4X4
     const int use_step_16 = (xd->n8_w >= 16);
@@ -207,16 +214,23 @@
   const TileInfo *const tile = &xd->tile;
   int i;
   uint8_t newmv_count = 0;
+  int row_offset = 0;
 #if CONFIG_CB4X4
   const BLOCK_SIZE bsize = xd->mi[0]->mbmi.sb_type;
-  const int mi_offset =
-      (bsize < BLOCK_8X8) ? mi_size_high[BLOCK_4X4] : mi_size_high[BLOCK_8X8];
-  if (bsize >= BLOCK_8X8) col_offset *= 2;
+  const int mi_offset = (bsize < BLOCK_8X8) || (abs(col_offset) > 1)
+                            ? mi_size_high[BLOCK_4X4]
+                            : mi_size_high[BLOCK_8X8];
+  if (bsize >= BLOCK_8X8 || abs(col_offset) > 1) col_offset *= 2;
+
+  if (bsize < BLOCK_8X8 && abs(col_offset) > 1) {
+    if (mi_row & 0x01) row_offset -= 1;
+    if (mi_col & 0x01) col_offset += 1;
+  }
 #else
   const int mi_offset = mi_size_wide[BLOCK_8X8];
 #endif
 
-  for (i = 0; i < xd->n8_h && *refmv_count < MAX_REF_MV_STACK_SIZE;) {
+  for (i = row_offset; i < xd->n8_h && *refmv_count < MAX_REF_MV_STACK_SIZE;) {
     POSITION mi_pos;
 #if CONFIG_CB4X4
     const int use_step_16 = (xd->n8_h >= 16);