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#include "vpx/vpx_integer.h" 18 19#include "vp9/common/vp9_common.h" 20 21#ifdef __cplusplus 22extern "C" { 23#endif 24 25typedef uint8_t vp9_prob; 26 27#define MAX_PROB 255 28 29#define vp9_prob_half ((vp9_prob) 128) 30 31typedef int8_t vp9_tree_index; 32 33#define TREE_SIZE(leaf_count) (2 * (leaf_count) - 2) 34 35#define vp9_complement(x) (255 - x) 36 37/* We build coding trees compactly in arrays. 38 Each node of the tree is a pair of vp9_tree_indices. 39 Array index often references a corresponding probability table. 40 Index <= 0 means done encoding/decoding and value = -Index, 41 Index > 0 means need another bit, specification at index. 42 Nonnegative indices are always even; processing begins at node 0. */ 43 44typedef const vp9_tree_index vp9_tree[]; 45 46static INLINE vp9_prob clip_prob(int p) { 47 return (p > 255) ? 255 : (p < 1) ? 1 : p; 48} 49 50// int64 is not needed for normal frame level calculations. 51// However when outputting entropy stats accumulated over many frames 52// or even clips we can overflow int math. 53#ifdef ENTROPY_STATS 54static INLINE vp9_prob get_prob(int num, int den) { 55 return (den == 0) ? 128u : clip_prob(((int64_t)num * 256 + (den >> 1)) / den); 56} 57#else 58static INLINE vp9_prob get_prob(int num, int den) { 59 return (den == 0) ? 128u : clip_prob((num * 256 + (den >> 1)) / den); 60} 61#endif 62 63static INLINE vp9_prob get_binary_prob(int n0, int n1) { 64 return get_prob(n0, n0 + n1); 65} 66 67/* This function assumes prob1 and prob2 are already within [1,255] range. */ 68static INLINE vp9_prob weighted_prob(int prob1, int prob2, int factor) { 69 return ROUND_POWER_OF_TWO(prob1 * (256 - factor) + prob2 * factor, 8); 70} 71 72static INLINE vp9_prob merge_probs(vp9_prob pre_prob, 73 const unsigned int ct[2], 74 unsigned int count_sat, 75 unsigned int max_update_factor) { 76 const vp9_prob prob = get_binary_prob(ct[0], ct[1]); 77 const unsigned int count = MIN(ct[0] + ct[1], count_sat); 78 const unsigned int factor = max_update_factor * count / count_sat; 79 return weighted_prob(pre_prob, prob, factor); 80} 81 82void vp9_tree_merge_probs(const vp9_tree_index *tree, const vp9_prob *pre_probs, 83 const unsigned int *counts, unsigned int count_sat, 84 unsigned int max_update_factor, vp9_prob *probs); 85 86 87DECLARE_ALIGNED(16, extern const uint8_t, vp9_norm[256]); 88 89#ifdef __cplusplus 90} // extern "C" 91#endif 92 93#endif // VP9_COMMON_VP9_PROB_H_ 94