1 files changed, 18 insertions, 0 deletions
diff --git a/third_party/aom/av1/encoder/cost.c b/third_party/aom/av1/encoder/cost.c
index e3151a5973..e33df53e45 100644
--- a/third_party/aom/av1/encoder/cost.c
+++ b/third_party/aom/av1/encoder/cost.c
@@ -65,3 +65,21 @@ void av1_cost_tokens_skip(int *costs, const aom_prob *probs, aom_tree tree) {
   costs[-tree[0]] = av1_cost_bit(probs[0], 0);
   cost(costs, tree, probs, 2, 0);
 }
+
+void av1_cost_tokens_from_cdf(int *costs, const aom_cdf_prob *cdf,
+                              const int *inv_map) {
+  int i;
+  aom_cdf_prob prev_cdf = 0;
+  for (i = 0;; ++i) {
+    const aom_cdf_prob p15 = AOM_ICDF(cdf[i]) - prev_cdf;
+    prev_cdf = AOM_ICDF(cdf[i]);
+
+    if (inv_map)
+      costs[inv_map[i]] = av1_cost_symbol(p15);
+    else
+      costs[i] = av1_cost_symbol(p15);
+
+    // Stop once we reach the end of the CDF
+    if (cdf[i] == AOM_ICDF(CDF_PROB_TOP)) break;
+  }
+}