Nearest / Zero Mv default entropy tweak.

Tweak to default mode context to account for the fact
that when there are no non zero motion candidates
Nearest is now the preferred mode for coding a 0,0
vector.

Also resolve duplicate function name and typos.

Change-Id: I76802788d46c84e3d1c771be216a537ab7b12817

1 files changed, 10 insertions, 4 deletions

diff --git a/vp9/encoder/vp9_bitstream.c b/vp9/encoder/vp9_bitstream.c
index 71109f8f4..0858b291f 100644
--- a/vp9/encoder/vp9_bitstream.c
+++ b/vp9/encoder/vp9_bitstream.c
@@ -221,8 +221,8 @@ static void update_refpred_stats(VP9_COMP *cpi) {
 //
 // The branch counts table is re-populated during the actual pack stage and in
 // the decoder to facilitate backwards update of the context.
-static void update_mode_probs(VP9_COMMON *cm,
-                              int mode_context[INTER_MODE_CONTEXTS][4]) {
+static void update_inter_mode_probs(VP9_COMMON *cm,
+                                    int mode_context[INTER_MODE_CONTEXTS][4]) {
   int i, j;
   unsigned int (*mv_ref_ct)[4][2];
 
@@ -813,7 +813,7 @@ static void pack_inter_mode_mvs(VP9_COMP *cpi, MODE_INFO *m,
     active_section = 3;
 #endif
 
-    // Is segment skip is not enabled code the mode.
+    // If segment skip is not enabled code the mode.
     if (!vp9_segfeature_active(xd, segment_id, SEG_LVL_SKIP)) {
       if (mi->sb_type) {
         write_sb_mv_ref(bc, mode, mv_ref_p);
@@ -1871,7 +1871,13 @@ void vp9_pack_bitstream(VP9_COMP *cpi, unsigned char *dest,
   if (pc->frame_type != KEY_FRAME) {
     int i, j;
     int new_context[INTER_MODE_CONTEXTS][4];
-    update_mode_probs(pc, new_context);
+    if (!cpi->dummy_packing) {
+      update_inter_mode_probs(pc, new_context);
+    } else {
+      // In dummy pack assume context unchanged.
+      vpx_memcpy(new_context, pc->fc.vp9_mode_contexts,
+                 sizeof(pc->fc.vp9_mode_contexts));
+    }
 
     for (i = 0; i < INTER_MODE_CONTEXTS; i++) {
       for (j = 0; j < 4; j++) {