76 строки
2.2 KiB
C
76 строки
2.2 KiB
C
/*
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* Copyright (c) 2010 The WebM project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include <assert.h>
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#include "./vpx_config.h"
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#include "vp9/common/vp9_treecoder.h"
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static void tree2tok(struct vp9_token *const p, vp9_tree t,
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int i, int v, int l) {
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v += v;
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++l;
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do {
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const vp9_tree_index j = t[i++];
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if (j <= 0) {
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p[-j].value = v;
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p[-j].len = l;
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} else
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tree2tok(p, t, j, v, l);
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} while (++v & 1);
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}
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void vp9_tokens_from_tree(struct vp9_token *p, vp9_tree t) {
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tree2tok(p, t, 0, 0, 0);
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}
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void vp9_tokens_from_tree_offset(struct vp9_token *p, vp9_tree t,
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int offset) {
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tree2tok(p - offset, t, 0, 0, 0);
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}
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static unsigned int convert_distribution(unsigned int i,
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vp9_tree tree,
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vp9_prob probs[],
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unsigned int branch_ct[][2],
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const unsigned int num_events[],
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unsigned int tok0_offset) {
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unsigned int left, right;
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if (tree[i] <= 0) {
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left = num_events[-tree[i] - tok0_offset];
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} else {
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left = convert_distribution(tree[i], tree, probs, branch_ct,
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num_events, tok0_offset);
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}
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if (tree[i + 1] <= 0)
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right = num_events[-tree[i + 1] - tok0_offset];
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else
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right = convert_distribution(tree[i + 1], tree, probs, branch_ct,
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num_events, tok0_offset);
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probs[i>>1] = get_binary_prob(left, right);
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branch_ct[i>>1][0] = left;
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branch_ct[i>>1][1] = right;
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return left + right;
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}
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void vp9_tree_probs_from_distribution(
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vp9_tree tree,
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vp9_prob probs [ /* n-1 */ ],
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unsigned int branch_ct [ /* n-1 */ ] [2],
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const unsigned int num_events[ /* n */ ],
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unsigned int tok0_offset) {
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convert_distribution(0, tree, probs, branch_ct, num_events, tok0_offset);
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}
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