1 /*
2 * Copyright (c) 2013 The WebM project authors. All Rights Reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10
11 #ifndef VP9_COMMON_VP9_PROB_H_
12 #define VP9_COMMON_VP9_PROB_H_
13
14 #include "./vpx_config.h"
15
16 #include "vpx_ports/mem.h"
17
18 #include "vp9/common/vp9_common.h"
19
20 #ifdef __cplusplus
21 extern "C" {
22 #endif
23
24 typedef uint8_t vp9_prob;
25
26 #define MAX_PROB 255
27
28 #define vp9_prob_half ((vp9_prob) 128)
29
30 typedef int8_t vp9_tree_index;
31
32 #define TREE_SIZE(leaf_count) (2 * (leaf_count) - 2)
33
34 #define vp9_complement(x) (255 - x)
35
36 #define MODE_MV_COUNT_SAT 20
37
38 /* We build coding trees compactly in arrays.
39 Each node of the tree is a pair of vp9_tree_indices.
40 Array index often references a corresponding probability table.
41 Index <= 0 means done encoding/decoding and value = -Index,
42 Index > 0 means need another bit, specification at index.
43 Nonnegative indices are always even; processing begins at node 0. */
44
45 typedef const vp9_tree_index vp9_tree[];
46
clip_prob(int p)47 static INLINE vp9_prob clip_prob(int p) {
48 return (p > 255) ? 255 : (p < 1) ? 1 : p;
49 }
50
get_prob(int num,int den)51 static INLINE vp9_prob get_prob(int num, int den) {
52 return (den == 0) ? 128u : clip_prob(((int64_t)num * 256 + (den >> 1)) / den);
53 }
54
get_binary_prob(int n0,int n1)55 static INLINE vp9_prob get_binary_prob(int n0, int n1) {
56 return get_prob(n0, n0 + n1);
57 }
58
59 /* This function assumes prob1 and prob2 are already within [1,255] range. */
weighted_prob(int prob1,int prob2,int factor)60 static INLINE vp9_prob weighted_prob(int prob1, int prob2, int factor) {
61 return ROUND_POWER_OF_TWO(prob1 * (256 - factor) + prob2 * factor, 8);
62 }
63
merge_probs(vp9_prob pre_prob,const unsigned int ct[2],unsigned int count_sat,unsigned int max_update_factor)64 static INLINE vp9_prob merge_probs(vp9_prob pre_prob,
65 const unsigned int ct[2],
66 unsigned int count_sat,
67 unsigned int max_update_factor) {
68 const vp9_prob prob = get_binary_prob(ct[0], ct[1]);
69 const unsigned int count = MIN(ct[0] + ct[1], count_sat);
70 const unsigned int factor = max_update_factor * count / count_sat;
71 return weighted_prob(pre_prob, prob, factor);
72 }
73
74 // MODE_MV_MAX_UPDATE_FACTOR (128) * count / MODE_MV_COUNT_SAT;
75 static const int count_to_update_factor[MODE_MV_COUNT_SAT + 1] = {
76 0, 6, 12, 19, 25, 32, 38, 44, 51, 57, 64,
77 70, 76, 83, 89, 96, 102, 108, 115, 121, 128
78 };
79
mode_mv_merge_probs(vp9_prob pre_prob,const unsigned int ct[2])80 static INLINE vp9_prob mode_mv_merge_probs(vp9_prob pre_prob,
81 const unsigned int ct[2]) {
82 const unsigned int den = ct[0] + ct[1];
83 if (den == 0) {
84 return pre_prob;
85 } else {
86 const unsigned int count = MIN(den, MODE_MV_COUNT_SAT);
87 const unsigned int factor = count_to_update_factor[count];
88 const vp9_prob prob =
89 clip_prob(((int64_t)(ct[0]) * 256 + (den >> 1)) / den);
90 return weighted_prob(pre_prob, prob, factor);
91 }
92 }
93
94 void vp9_tree_merge_probs(const vp9_tree_index *tree, const vp9_prob *pre_probs,
95 const unsigned int *counts, vp9_prob *probs);
96
97
98 DECLARE_ALIGNED(16, extern const uint8_t, vp9_norm[256]);
99
100 #ifdef __cplusplus
101 } // extern "C"
102 #endif
103
104 #endif // VP9_COMMON_VP9_PROB_H_
105