diff -r 000000000000 -r 6474c204b198 media/libvpx/vp9/encoder/vp9_treewriter.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/media/libvpx/vp9/encoder/vp9_treewriter.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,87 @@
+/*
+ *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+
+#ifndef VP9_ENCODER_VP9_TREEWRITER_H_
+#define VP9_ENCODER_VP9_TREEWRITER_H_
+
+/* Trees map alphabets into huffman-like codes suitable for an arithmetic
+   bit coder.  Timothy S Murphy  11 October 2004 */
+
+#include "vp9/common/vp9_treecoder.h"
+
+#include "vp9/encoder/vp9_boolhuff.h"       /* for now */
+
+
+#define vp9_write_prob(w, v) vp9_write_literal((w), (v), 8)
+
+/* Approximate length of an encoded bool in 256ths of a bit at given prob */
+
+#define vp9_cost_zero(x) (vp9_prob_cost[x])
+#define vp9_cost_one(x) vp9_cost_zero(vp9_complement(x))
+
+#define vp9_cost_bit(x, b) vp9_cost_zero((b) ? vp9_complement(x) : (x))
+
+/* VP8BC version is scaled by 2^20 rather than 2^8; see bool_coder.h */
+
+
+/* Both of these return bits, not scaled bits. */
+static INLINE unsigned int cost_branch256(const unsigned int ct[2],
+                                          vp9_prob p) {
+  return ct[0] * vp9_cost_zero(p) + ct[1] * vp9_cost_one(p);
+}
+
+static INLINE unsigned int cost_branch(const unsigned int ct[2],
+                                       vp9_prob p) {
+  return cost_branch256(ct, p) >> 8;
+}
+
+
+static INLINE void treed_write(vp9_writer *w,
+                               vp9_tree tree, const vp9_prob *probs,
+                               int bits, int len) {
+  vp9_tree_index i = 0;
+
+  do {
+    const int bit = (bits >> --len) & 1;
+    vp9_write(w, bit, probs[i >> 1]);
+    i = tree[i + bit];
+  } while (len);
+}
+
+static INLINE void write_token(vp9_writer *w, vp9_tree tree,
+                               const vp9_prob *probs,
+                               const struct vp9_token *token) {
+  treed_write(w, tree, probs, token->value, token->len);
+}
+
+static INLINE int treed_cost(vp9_tree tree, const vp9_prob *probs,
+                             int bits, int len) {
+  int cost = 0;
+  vp9_tree_index i = 0;
+
+  do {
+    const int bit = (bits >> --len) & 1;
+    cost += vp9_cost_bit(probs[i >> 1], bit);
+    i = tree[i + bit];
+  } while (len);
+
+  return cost;
+}
+
+static INLINE int cost_token(vp9_tree tree, const vp9_prob *probs,
+                             const struct vp9_token *token) {
+  return treed_cost(tree, probs, token->value, token->len);
+}
+
+void vp9_cost_tokens(int *costs, const vp9_prob *probs, vp9_tree tree);
+void vp9_cost_tokens_skip(int *costs, const vp9_prob *probs, vp9_tree tree);
+
+#endif  // VP9_ENCODER_VP9_TREEWRITER_H_