Set mv to zero if the second ref does not exist

Change-Id: I94b936c2642981eccdff073fc71c12e2dccb7909

3 files changed, 12 insertions, 0 deletions

diff --git a/vp9/encoder/vp9_encodeframe.c b/vp9/encoder/vp9_encodeframe.c
index f9a64f3da..3e83a264f 100644
--- a/vp9/encoder/vp9_encodeframe.c
+++ b/vp9/encoder/vp9_encodeframe.c
@@ -3847,6 +3847,9 @@ static void assign_motion_vector_info(const int block_width_4x4,
       const int col_4x4 = col_start_4x4 + j;
       const int unit_index = row_4x4 * num_unit_cols + col_4x4;
       if (row_4x4 >= num_unit_rows || col_4x4 >= num_unit_cols) continue;
+      if (source_ref_frame[1] == NONE) {
+        assert(source_mv[1]->row == 0 && source_mv[1]->col == 0);
+      }
       motion_vector_info[unit_index].ref_frame[0] = source_ref_frame[0];
       motion_vector_info[unit_index].ref_frame[1] = source_ref_frame[1];
       motion_vector_info[unit_index].mv[0].as_mv.row = source_mv[0]->row;
diff --git a/vp9/encoder/vp9_rdopt.c b/vp9/encoder/vp9_rdopt.c
index fa7472ca6..39b99d50c 100644
--- a/vp9/encoder/vp9_rdopt.c
+++ b/vp9/encoder/vp9_rdopt.c
@@ -4733,6 +4733,13 @@ void vp9_rd_pick_inter_mode_sub8x8(VP9_COMP *cpi, TileDataEnc *tile_data,
     mi->mv[0].as_int = xd->mi[0]->bmi[3].as_mv[0].as_int;
     mi->mv[1].as_int = xd->mi[0]->bmi[3].as_mv[1].as_int;
   }
+  // If the second reference does not exist, set the corresponding mv to zero.
+  if (mi->ref_frame[1] == NONE) {
+    mi->mv[1].as_int = 0;
+    for (i = 0; i < 4; ++i) {
+      mi->bmi[i].as_mv[1].as_int = 0;
+    }
+  }
 
   for (i = 0; i < REFERENCE_MODES; ++i) {
     if (best_pred_rd[i] == INT64_MAX)
diff --git a/vp9/simple_encode.h b/vp9/simple_encode.h
index 148f8985d..60f405e97 100644
--- a/vp9/simple_encode.h
+++ b/vp9/simple_encode.h
@@ -59,8 +59,10 @@ struct MotionVectorInfo {
   // or kAltRefFrame.
   RefFrameType ref_frame[2];
   // The row offset of motion vectors in the unit of pixel.
+  // If the second motion vector does not exist, the value is 0.
   double mv_row[2];
   // The column offset of motion vectors in the unit of pixel.
+  // If the second motion vector does not exist, the value is 0.
   double mv_column[2];
 };