Skip checking compound modes with same sign bias for sub8x8

Drop the check of compound modes where the two reference frames
share the same reference frame sign bias in sub8x8 coding blocks.

Change-Id: I47b45256582b2b5ea1372c9130d8f28cd226a29c

diff --git a/vp9/encoder/vp9_rdopt.c b/vp9/encoder/vp9_rdopt.c
index 3c15af36813ced1138af29cc78a42160296e0cc2..8fa01bd681c72ecc58d72d6ba7dd86b607db0919 100644 (file)
--- a/vp9/encoder/vp9_rdopt.c
+++ b/vp9/encoder/vp9_rdopt.c
@@ -3985,6 +3985,11 @@ void vp9_rd_pick_inter_mode_sub8x8(VP9_COMP *cpi, TileDataEnc *tile_data,
     comp_pred = second_ref_frame > INTRA_FRAME;
     if (comp_pred) {
       if (!cpi->allow_comp_inter_inter) continue;
+
+      if (cm->ref_frame_sign_bias[ref_frame] ==
+          cm->ref_frame_sign_bias[second_ref_frame])
+        continue;
+
       if (!(cpi->ref_frame_flags & flag_list[second_ref_frame])) continue;
       // Do not allow compound prediction if the segment level reference frame
       // feature is in use as in this case there can only be one reference.