summaryrefslogtreecommitdiffstats
path: root/media/libvpx/vp9/common/vp9_prob.h
blob: c69c62c81f85517ab3cfb4897b99d468190cafe0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
/*
 *  Copyright (c) 2013 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_PROB_H_
#define VP9_COMMON_VP9_PROB_H_

#include "./vpx_config.h"

#include "vpx_ports/mem.h"

#include "vp9/common/vp9_common.h"

#ifdef __cplusplus
extern "C" {
#endif

typedef uint8_t vp9_prob;

#define MAX_PROB 255

#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)

#define MODE_MV_COUNT_SAT 20

/* 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[];

static INLINE vp9_prob clip_prob(int p) {
  return (p > 255) ? 255 : (p < 1) ? 1 : p;
}

static INLINE vp9_prob get_prob(int num, int den) {
  return (den == 0) ? 128u : clip_prob(((int64_t)num * 256 + (den >> 1)) / den);
}

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);
}

// MODE_MV_MAX_UPDATE_FACTOR (128) * count / MODE_MV_COUNT_SAT;
static const int count_to_update_factor[MODE_MV_COUNT_SAT + 1] = {
  0, 6, 12, 19, 25, 32, 38, 44, 51, 57, 64,
  70, 76, 83, 89, 96, 102, 108, 115, 121, 128
};

static INLINE vp9_prob mode_mv_merge_probs(vp9_prob pre_prob,
                                           const unsigned int ct[2]) {
  const unsigned int den = ct[0] + ct[1];
  if (den == 0) {
    return pre_prob;
  } else {
    const unsigned int count = MIN(den, MODE_MV_COUNT_SAT);
    const unsigned int factor = count_to_update_factor[count];
    const vp9_prob prob =
        clip_prob(((int64_t)(ct[0]) * 256 + (den >> 1)) / den);
    return weighted_prob(pre_prob, prob, factor);
  }
}

void vp9_tree_merge_probs(const vp9_tree_index *tree, const vp9_prob *pre_probs,
                          const unsigned int *counts, vp9_prob *probs);


DECLARE_ALIGNED(16, extern const uint8_t, vp9_norm[256]);

#ifdef __cplusplus
}  // extern "C"
#endif

#endif  // VP9_COMMON_VP9_PROB_H_