vp10: use subexp probability updates for MV probs.

See issue 1040 point 2.

Change-Id: I0b37fe74be764610696620f1fe296dc74e4806d7

vp10/decoder/decodeframe.c

@@ -170,8 +170,12 @@ static void read_frame_reference_mode_probs(VP10_COMMON *cm, vpx_reader *r) {
 static void update_mv_probs(vpx_prob *p, int n, vpx_reader *r) {
   int i;
   for (i = 0; i < n; ++i)
+#if CONFIG_MISC_FIXES
+    vp10_diff_update_prob(r, &p[i]);
+#else
     if (vpx_read(r, MV_UPDATE_PROB))
       p[i] = (vpx_read_literal(r, 7) << 1) | 1;
+#endif
 }
 
 static void read_mv_probs(nmv_context *ctx, int allow_hp, vpx_reader *r) {

vp10/encoder/encodemv.c

@@ -15,6 +15,7 @@
 
 #include "vp10/encoder/cost.h"
 #include "vp10/encoder/encodemv.h"
+#include "vp10/encoder/subexp.h"
 
 #include "vpx_dsp/vpx_dsp_common.h"
 
@@ -134,8 +135,12 @@ static void build_nmv_component_cost_table(int *mvcost,
   }
 }
 
-static int update_mv(vpx_writer *w, const unsigned int ct[2], vpx_prob *cur_p,
-                     vpx_prob upd_p) {
+static void update_mv(vpx_writer *w, const unsigned int ct[2], vpx_prob *cur_p,
+                      vpx_prob upd_p) {
+#if CONFIG_MISC_FIXES
+  (void) upd_p;
+  vp10_cond_prob_diff_update(w, cur_p, ct);
+#else
   const vpx_prob new_p = get_binary_prob(ct[0], ct[1]) | 1;
   const int update = cost_branch256(ct, *cur_p) + vp10_cost_zero(upd_p) >
                      cost_branch256(ct, new_p) + vp10_cost_one(upd_p) + 7 * 256;
@@ -144,7 +149,7 @@ static int update_mv(vpx_writer *w, const unsigned int ct[2], vpx_prob *cur_p,
     *cur_p = new_p;
     vpx_write_literal(w, new_p >> 1, 7);
   }
-  return update;
+#endif
 }
 
 static void write_mv_update(const vpx_tree_index *tree,