Disable compound mode in sub8x8 coding blocks
Disable the support of compound prediction modes for sub8x8 codking
blocks. Make the rate-distortion optimizations process account for
such constraints.
With the use 2x2 chroma prediction block, this makes the wrost case
number of inter predictors same as vp9. It affects the coding
gains by 0.35% for lowres, 0.17% for midres, and 0.08% for hdres.
The encoding speed is up by 10%.
Change-Id: Ieb2a83030676911baa403e586f1f800cbf485d81
diff --git a/av1/decoder/decodemv.c b/av1/decoder/decodemv.c
index 06534e2..dff0d5c 100644
--- a/av1/decoder/decodemv.c
+++ b/av1/decoder/decodemv.c
@@ -1011,6 +1011,11 @@
aom_reader *r) {
if (cm->reference_mode == REFERENCE_MODE_SELECT) {
const int ctx = av1_get_reference_mode_context(cm, xd);
+
+#if !SUB8X8_COMP_REF
+ if (xd->mi[0]->mbmi.sb_type < BLOCK_8X8) return SINGLE_REFERENCE;
+#endif
+
const REFERENCE_MODE mode =
(REFERENCE_MODE)aom_read(r, cm->fc->comp_inter_prob[ctx], ACCT_STR);
FRAME_COUNTS *counts = xd->counts;
@@ -1042,8 +1047,8 @@
const int idx = cm->ref_frame_sign_bias[cm->comp_fixed_ref];
#endif // CONFIG_EXT_REFS
const int ctx = av1_get_pred_context_comp_ref_p(cm, xd);
- const int bit = aom_read(r, fc->comp_ref_prob[ctx][0], ACCT_STR);
+ const int bit = aom_read(r, fc->comp_ref_prob[ctx][0], ACCT_STR);
if (counts) ++counts->comp_ref[ctx][0][bit];
#if CONFIG_EXT_REFS
