commit 95cb0d78c369089044223c123172632ea9ed1916
author Jim Bankoski <jimbankoski@google.com> Fri Jan 11 15:20:06 2019 -0800
committer James Bankoski <jimbankoski@google.com> Tue Jan 15 20:29:56 2019 +0000
tree 109d05ae87d26eacd77676aa6a7a3fcb3b3dbecd
parent b6540c0207e7c0abcbcef80689e3d30ae1ef2fd3

update_coeff_eob : minor optimization

tmp_levels unnecessary as all of the functions for calculating
context take a parameter as to whether this is end of block and
if so don't access levels at all.   If the cost is actually less
then we'll set the values.

Change-Id: Ie2d460e874e2ee31d6f12980af16da06d84a0da8

av1/common/txb_common.h

diff --git a/av1/common/txb_common.h b/av1/common/txb_common.h
index 5e5ead0..8a3932d 100644
--- a/av1/common/txb_common.h
+++ b/av1/common/txb_common.h
@@ -159,6 +159,19 @@
   return mag + 14;
 }
 
+static AOM_FORCE_INLINE int get_br_ctx_eob(const int c,  // raster order
+                                           const int bwl,
+                                           const TX_CLASS tx_class) {
+  const int row = c >> bwl;
+  const int col = c - (row << bwl);
+  if (c == 0) return 0;
+  if ((tx_class == TX_CLASS_2D && row < 2 && col < 2) ||
+      (tx_class == TX_CLASS_HORIZ && col == 0) ||
+      (tx_class == TX_CLASS_VERT && row == 0))
+    return 7;
+  return 14;
+}
+
 static AOM_FORCE_INLINE int get_br_ctx(const uint8_t *const levels,
                                        const int c,  // raster order
                                        const int bwl, const TX_CLASS tx_class) {

av1/encoder/encodetxb.c

diff --git a/av1/encoder/encodetxb.c b/av1/encoder/encodetxb.c
index edd5f39..fc2bc90 100644
--- a/av1/encoder/encodetxb.c
+++ b/av1/encoder/encodetxb.c
@@ -1322,7 +1322,11 @@
       cost += av1_cost_literal(1);
     }
     if (abs_qc > NUM_BASE_LEVELS) {
-      const int br_ctx = get_br_ctx(levels, ci, bwl, tx_class);
+      int br_ctx;
+      if (is_last)
+        br_ctx = get_br_ctx_eob(ci, bwl, tx_class);
+      else
+        br_ctx = get_br_ctx(levels, ci, bwl, tx_class);
       cost += get_br_cost(abs_qc, br_ctx, txb_costs->lps_cost[br_ctx]);
       cost += get_golomb_cost(abs_qc);
     }
@@ -1478,13 +1482,6 @@
 
     int lower_level_new_eob = 0;
     const int new_eob = si + 1;
-    uint8_t tmp_levels[3];
-    for (int ni = 0; ni < *nz_num; ++ni) {
-      const int last_ci = nz_ci[ni];
-      tmp_levels[ni] = levels[get_padded_idx(last_ci, bwl)];
-      levels[get_padded_idx(last_ci, bwl)] = 0;
-    }
-
     const int coeff_ctx_new_eob = get_lower_levels_ctx_eob(bwl, height, si);
     const int new_eob_cost =
         get_eob_cost(new_eob, txb_eob_costs, txb_costs, tx_class);
@@ -1521,7 +1518,7 @@
     if (sharpness == 0 && rd_new_eob < rd) {
       for (int ni = 0; ni < *nz_num; ++ni) {
         int last_ci = nz_ci[ni];
-        // levels[get_padded_idx(last_ci, bwl)] = 0;
+        levels[get_padded_idx(last_ci, bwl)] = 0;
         qcoeff[last_ci] = 0;
         dqcoeff[last_ci] = 0;
       }
@@ -1531,10 +1528,6 @@
       *accu_dist = dist_new_eob;
       lower_level = lower_level_new_eob;
     } else {
-      for (int ni = 0; ni < *nz_num; ++ni) {
-        const int last_ci = nz_ci[ni];
-        levels[get_padded_idx(last_ci, bwl)] = tmp_levels[ni];
-      }
       *accu_rate += rate;
       *accu_dist += dist;
     }