Add ARF validation for compound inter mode check

This commit enforces ARF validation check for compound inter modes.
It avoids potential access to ARF in the encoding process if it
is not allowed.

Change-Id: I055fec946b5d19d97937dc9001e1e564923e2439

diff --git a/vp9/encoder/vp9_rdopt.c b/vp9/encoder/vp9_rdopt.c
index 088776982d7ba8b7d49899a8b3de0e9810df1085..f3091cc88ccb36799193c82dac2c24e5c267280b 100644 (file)
--- a/vp9/encoder/vp9_rdopt.c
+++ b/vp9/encoder/vp9_rdopt.c
@@ -2793,6 +2793,15 @@ int64_t vp9_rd_pick_inter_mode_sb(VP9_COMP *cpi, MACROBLOCK *x,
       if (!cm->allow_comp_inter_inter)
         continue;
 
+      // Skip compound inter modes if ARF is not available.
+      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.
+      if (vp9_segfeature_active(seg, segment_id, SEG_LVL_REF_FRAME))
+        continue;
+
       if ((mode_search_skip_flags & FLAG_SKIP_COMP_BESTINTRA) &&
           best_mode_index >= 0 && best_mbmode.ref_frame[0] == INTRA_FRAME)
         continue;