1/*
2 *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11#include "vp9/encoder/vp9_treewriter.h"
12
13static void tree2tok(struct vp9_token *tokens, const vpx_tree_index *tree,
14                     int i, int v, int l) {
15  v += v;
16  ++l;
17
18  do {
19    const vpx_tree_index j = tree[i++];
20    if (j <= 0) {
21      tokens[-j].value = v;
22      tokens[-j].len = l;
23    } else {
24      tree2tok(tokens, tree, j, v, l);
25    }
26  } while (++v & 1);
27}
28
29void vp9_tokens_from_tree(struct vp9_token *tokens,
30                          const vpx_tree_index *tree) {
31  tree2tok(tokens, tree, 0, 0, 0);
32}
33
34static unsigned int convert_distribution(unsigned int i, vpx_tree tree,
35                                         unsigned int branch_ct[][2],
36                                         const unsigned int num_events[]) {
37  unsigned int left, right;
38
39  if (tree[i] <= 0)
40    left = num_events[-tree[i]];
41  else
42    left = convert_distribution(tree[i], tree, branch_ct, num_events);
43
44  if (tree[i + 1] <= 0)
45    right = num_events[-tree[i + 1]];
46  else
47    right = convert_distribution(tree[i + 1], tree, branch_ct, num_events);
48
49  branch_ct[i >> 1][0] = left;
50  branch_ct[i >> 1][1] = right;
51  return left + right;
52}
53
54void vp9_tree_probs_from_distribution(vpx_tree tree,
55                                      unsigned int branch_ct[/* n-1 */][2],
56                                      const unsigned int num_events[/* n */]) {
57  convert_distribution(0, tree, branch_ct, num_events);
58}
59