aom/vp10/encoder/treewriter.c

59 строки
1.8 KiB
C

/*
* 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.
*/
#include "vp10/encoder/treewriter.h"
static void tree2tok(struct vp10_token *tokens, const vpx_tree_index *tree,
int i, int v, int l) {
v += v;
++l;
do {
const vpx_tree_index j = tree[i++];
if (j <= 0) {
tokens[-j].value = v;
tokens[-j].len = l;
} else {
tree2tok(tokens, tree, j, v, l);
}
} while (++v & 1);
}
void vp10_tokens_from_tree(struct vp10_token *tokens,
const vpx_tree_index *tree) {
tree2tok(tokens, tree, 0, 0, 0);
}
static unsigned int convert_distribution(unsigned int i, vpx_tree tree,
unsigned int branch_ct[][2],
const unsigned int num_events[]) {
unsigned int left, right;
if (tree[i] <= 0)
left = num_events[-tree[i]];
else
left = convert_distribution(tree[i], tree, branch_ct, num_events);
if (tree[i + 1] <= 0)
right = num_events[-tree[i + 1]];
else
right = convert_distribution(tree[i + 1], tree, branch_ct, num_events);
branch_ct[i >> 1][0] = left;
branch_ct[i >> 1][1] = right;
return left + right;
}
void vp10_tree_probs_from_distribution(vpx_tree tree,
unsigned int branch_ct[/* n-1 */][2],
const unsigned int num_events[/* n */]) {
convert_distribution(0, tree, branch_ct, num_events);
}