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 
tree2tok(struct vp9_token * tokens,const vpx_tree_index * tree,int i,int v,int l)13 static 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 
vp9_tokens_from_tree(struct vp9_token * tokens,const vpx_tree_index * tree)29 void vp9_tokens_from_tree(struct vp9_token *tokens,
30                           const vpx_tree_index *tree) {
31   tree2tok(tokens, tree, 0, 0, 0);
32 }
33 
convert_distribution(unsigned int i,vpx_tree tree,unsigned int branch_ct[][2],const unsigned int num_events[])34 static 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 
vp9_tree_probs_from_distribution(vpx_tree tree,unsigned int branch_ct[][2],const unsigned int num_events[])54 void 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