ref: 42b7c44b2fa40ff8b070809e79f9931526f5fe52
dir: /vpx_dsp/prob.h/
/* * 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 VPX_DSP_PROB_H_ #define VPX_DSP_PROB_H_ #include "./vpx_config.h" #include "./vpx_dsp_common.h" #include "vpx_ports/mem.h" #ifdef __cplusplus extern "C" { #endif typedef uint8_t vpx_prob; #define MAX_PROB 255 #define vpx_prob_half ((vpx_prob) 128) typedef int8_t vpx_tree_index; #define TREE_SIZE(leaf_count) (2 * (leaf_count) - 2) #define vpx_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 vpx_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 vpx_tree_index vpx_tree[]; static INLINE vpx_prob clip_prob(int p) { return (p > 255) ? 255 : (p < 1) ? 1 : p; } static INLINE vpx_prob get_prob(int num, int den) { return (den == 0) ? 128u : clip_prob(((int64_t)num * 256 + (den >> 1)) / den); } static INLINE vpx_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 vpx_prob weighted_prob(int prob1, int prob2, int factor) { return ROUND_POWER_OF_TWO(prob1 * (256 - factor) + prob2 * factor, 8); } static INLINE vpx_prob merge_probs(vpx_prob pre_prob, const unsigned int ct[2], unsigned int count_sat, unsigned int max_update_factor) { const vpx_prob prob = get_binary_prob(ct[0], ct[1]); const unsigned int count = VPXMIN(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 vpx_prob mode_mv_merge_probs(vpx_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 = VPXMIN(den, MODE_MV_COUNT_SAT); const unsigned int factor = count_to_update_factor[count]; const vpx_prob prob = clip_prob(((int64_t)(ct[0]) * 256 + (den >> 1)) / den); return weighted_prob(pre_prob, prob, factor); } } void vpx_tree_merge_probs(const vpx_tree_index *tree, const vpx_prob *pre_probs, const unsigned int *counts, vpx_prob *probs); DECLARE_ALIGNED(16, extern const uint8_t, vpx_norm[256]); #ifdef __cplusplus } // extern "C" #endif #endif // VPX_DSP_PROB_H_