139 lines
3.0 KiB
C
139 lines
3.0 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 "vpx_config.h"
|
|
|
|
#if defined(CONFIG_DEBUG) && CONFIG_DEBUG
|
|
#include <assert.h>
|
|
#endif
|
|
#include <stdio.h>
|
|
|
|
#include "vp9/common/vp9_treecoder.h"
|
|
|
|
static void tree2tok(
|
|
struct vp9_token_struct *const p,
|
|
vp9_tree t,
|
|
int i,
|
|
int v,
|
|
int L
|
|
) {
|
|
v += v;
|
|
++L;
|
|
|
|
do {
|
|
const vp9_tree_index j = t[i++];
|
|
|
|
if (j <= 0) {
|
|
p[-j].value = v;
|
|
p[-j].Len = L;
|
|
} else
|
|
tree2tok(p, t, j, v, L);
|
|
} while (++v & 1);
|
|
}
|
|
|
|
void vp9_tokens_from_tree(struct vp9_token_struct *p, vp9_tree t) {
|
|
tree2tok(p, t, 0, 0, 0);
|
|
}
|
|
|
|
void vp9_tokens_from_tree_offset(struct vp9_token_struct *p, vp9_tree t,
|
|
int offset) {
|
|
tree2tok(p - offset, t, 0, 0, 0);
|
|
}
|
|
|
|
static void branch_counts(
|
|
int n, /* n = size of alphabet */
|
|
vp9_token tok [ /* n */ ],
|
|
vp9_tree tree,
|
|
unsigned int branch_ct [ /* n-1 */ ] [2],
|
|
const unsigned int num_events[ /* n */ ]
|
|
) {
|
|
const int tree_len = n - 1;
|
|
int t = 0;
|
|
|
|
#if CONFIG_DEBUG
|
|
assert(tree_len);
|
|
#endif
|
|
|
|
do {
|
|
branch_ct[t][0] = branch_ct[t][1] = 0;
|
|
} while (++t < tree_len);
|
|
|
|
t = 0;
|
|
|
|
do {
|
|
int L = tok[t].Len;
|
|
const int enc = tok[t].value;
|
|
const unsigned int ct = num_events[t];
|
|
|
|
vp9_tree_index i = 0;
|
|
|
|
do {
|
|
const int b = (enc >> --L) & 1;
|
|
const int j = i >> 1;
|
|
#if CONFIG_DEBUG
|
|
assert(j < tree_len && 0 <= L);
|
|
#endif
|
|
|
|
branch_ct [j] [b] += ct;
|
|
i = tree[ i + b];
|
|
} while (i > 0);
|
|
|
|
#if CONFIG_DEBUG
|
|
assert(!L);
|
|
#endif
|
|
} while (++t < n);
|
|
|
|
}
|
|
|
|
|
|
void vp9_tree_probs_from_distribution(
|
|
int n, /* n = size of alphabet */
|
|
vp9_token tok [ /* n */ ],
|
|
vp9_tree tree,
|
|
vp9_prob probs [ /* n-1 */ ],
|
|
unsigned int branch_ct [ /* n-1 */ ] [2],
|
|
const unsigned int num_events[ /* n */ ],
|
|
unsigned int Pfac,
|
|
int rd
|
|
) {
|
|
const int tree_len = n - 1;
|
|
int t = 0;
|
|
|
|
branch_counts(n, tok, tree, branch_ct, num_events);
|
|
|
|
do {
|
|
const unsigned int *const c = branch_ct[t];
|
|
const unsigned int tot = c[0] + c[1];
|
|
|
|
#if CONFIG_DEBUG
|
|
assert(tot < (1 << 24)); /* no overflow below */
|
|
#endif
|
|
|
|
if (tot) {
|
|
const unsigned int p = ((c[0] * Pfac) + (rd ? tot >> 1 : 0)) / tot;
|
|
probs[t] = p < 256 ? (p ? p : 1) : 255; /* agree w/old version for now */
|
|
} else
|
|
probs[t] = vp9_prob_half;
|
|
} while (++t < tree_len);
|
|
}
|
|
|
|
vp9_prob vp9_bin_prob_from_distribution(const unsigned int counts[2]) {
|
|
int tot_count = counts[0] + counts[1];
|
|
vp9_prob prob;
|
|
if (tot_count) {
|
|
prob = (counts[0] * 255 + (tot_count >> 1)) / tot_count;
|
|
prob += !prob;
|
|
} else {
|
|
prob = 128;
|
|
}
|
|
return prob;
|
|
}
|