4ac6a2552b
Writing custom coeff branch count calculation (which is much clearer) in adapt_coef_probs() function. Removing vp9_treecoder.c file. Change-Id: I8880fb7a39996c8bcf6cd0acf9898a8c712ba91f
112 lines
4.3 KiB
C
112 lines
4.3 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.
|
|
*/
|
|
|
|
#ifndef VP9_COMMON_VP9_TREECODER_H_
|
|
#define VP9_COMMON_VP9_TREECODER_H_
|
|
|
|
#include "./vpx_config.h"
|
|
#include "vpx/vpx_integer.h"
|
|
#include "vp9/common/vp9_common.h"
|
|
|
|
typedef uint8_t vp9_prob;
|
|
|
|
#define vp9_prob_half ((vp9_prob) 128)
|
|
|
|
typedef int8_t vp9_tree_index;
|
|
|
|
#define TREE_SIZE(leaf_count) (2 * (leaf_count) - 2)
|
|
|
|
#define vp9_complement(x) (255 - x)
|
|
|
|
/* We build coding trees compactly in arrays.
|
|
Each node of the tree is a pair of vp9_tree_indices.
|
|
Array index often references a corresponding probability table.
|
|
Index <= 0 means done encoding/decoding and value = -Index,
|
|
Index > 0 means need another bit, specification at index.
|
|
Nonnegative indices are always even; processing begins at node 0. */
|
|
|
|
typedef const vp9_tree_index vp9_tree[];
|
|
|
|
/* Convert array of token occurrence counts into a table of probabilities
|
|
for the associated binary encoding tree. Also writes count of branches
|
|
taken for each node on the tree; this facilitiates decisions as to
|
|
probability updates. */
|
|
|
|
static INLINE vp9_prob clip_prob(int p) {
|
|
return (p > 255) ? 255u : (p < 1) ? 1u : p;
|
|
}
|
|
|
|
// int64 is not needed for normal frame level calculations.
|
|
// However when outputing entropy stats accumulated over many frames
|
|
// or even clips we can overflow int math.
|
|
#ifdef ENTROPY_STATS
|
|
static INLINE vp9_prob get_prob(int num, int den) {
|
|
return (den == 0) ? 128u : clip_prob(((int64_t)num * 256 + (den >> 1)) / den);
|
|
}
|
|
#else
|
|
static INLINE vp9_prob get_prob(int num, int den) {
|
|
return (den == 0) ? 128u : clip_prob((num * 256 + (den >> 1)) / den);
|
|
}
|
|
#endif
|
|
|
|
static INLINE vp9_prob get_binary_prob(int n0, int n1) {
|
|
return get_prob(n0, n0 + n1);
|
|
}
|
|
|
|
/* this function assumes prob1 and prob2 are already within [1,255] range */
|
|
static INLINE vp9_prob weighted_prob(int prob1, int prob2, int factor) {
|
|
return ROUND_POWER_OF_TWO(prob1 * (256 - factor) + prob2 * factor, 8);
|
|
}
|
|
|
|
static INLINE vp9_prob merge_probs(vp9_prob pre_prob,
|
|
const unsigned int ct[2],
|
|
unsigned int count_sat,
|
|
unsigned int max_update_factor) {
|
|
const vp9_prob prob = get_binary_prob(ct[0], ct[1]);
|
|
const unsigned int count = MIN(ct[0] + ct[1], count_sat);
|
|
const unsigned int factor = max_update_factor * count / count_sat;
|
|
return weighted_prob(pre_prob, prob, factor);
|
|
}
|
|
|
|
static unsigned int tree_merge_probs_impl(unsigned int i,
|
|
const vp9_tree_index *tree,
|
|
const vp9_prob *pre_probs,
|
|
const unsigned int *counts,
|
|
unsigned int count_sat,
|
|
unsigned int max_update_factor,
|
|
vp9_prob *probs) {
|
|
const int l = tree[i];
|
|
const unsigned int left_count = (l <= 0)
|
|
? counts[-l]
|
|
: tree_merge_probs_impl(l, tree, pre_probs, counts,
|
|
count_sat, max_update_factor, probs);
|
|
const int r = tree[i + 1];
|
|
const unsigned int right_count = (r <= 0)
|
|
? counts[-r]
|
|
: tree_merge_probs_impl(r, tree, pre_probs, counts,
|
|
count_sat, max_update_factor, probs);
|
|
const unsigned int ct[2] = { left_count, right_count };
|
|
probs[i >> 1] = merge_probs(pre_probs[i >> 1], ct,
|
|
count_sat, max_update_factor);
|
|
return left_count + right_count;
|
|
}
|
|
|
|
static void tree_merge_probs(const vp9_tree_index *tree,
|
|
const vp9_prob *pre_probs,
|
|
const unsigned int *counts,
|
|
unsigned int count_sat,
|
|
unsigned int max_update_factor, vp9_prob *probs) {
|
|
tree_merge_probs_impl(0, tree, pre_probs, counts,
|
|
count_sat, max_update_factor, probs);
|
|
}
|
|
|
|
|
|
#endif // VP9_COMMON_VP9_TREECODER_H_
|