aom/aom_dsp/prob.h

193 строки
5.9 KiB
C

/*
* Copyright (c) 2016, Alliance for Open Media. All rights reserved
*
* This source code is subject to the terms of the BSD 2 Clause License and
* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
* was not distributed with this source code in the LICENSE file, you can
* obtain it at www.aomedia.org/license/software. If the Alliance for Open
* Media Patent License 1.0 was not distributed with this source code in the
* PATENTS file, you can obtain it at www.aomedia.org/license/patent.
*/
#ifndef AOM_DSP_PROB_H_
#define AOM_DSP_PROB_H_
#include <assert.h>
#include "./aom_config.h"
#include "./aom_dsp_common.h"
#include "aom_ports/bitops.h"
#include "aom_ports/mem.h"
#if !CONFIG_ANS
#include "aom_dsp/entcode.h"
#endif
#ifdef __cplusplus
extern "C" {
#endif
typedef uint8_t aom_prob;
// TODO(negge): Rename this aom_prob once we remove vpxbool.
typedef uint16_t aom_cdf_prob;
#define CDF_SIZE(x) ((x) + 1)
#define CDF_PROB_BITS 15
#define CDF_PROB_TOP (1 << CDF_PROB_BITS)
#if !CONFIG_ANS
#define AOM_ICDF OD_ICDF
#else
#define AOM_ICDF(x) (x)
#endif
#define MAX_PROB 255
#define aom_prob_half ((aom_prob)128)
typedef int8_t aom_tree_index;
#define TREE_SIZE(leaf_count) (-2 + 2 * (leaf_count))
#define MODE_MV_COUNT_SAT 20
/* We build coding trees compactly in arrays.
Each node of the tree is a pair of aom_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 aom_tree_index aom_tree[];
static INLINE aom_prob get_prob(unsigned int num, unsigned int den) {
assert(den != 0);
{
const int p = (int)(((uint64_t)num * 256 + (den >> 1)) / den);
// (p > 255) ? 255 : (p < 1) ? 1 : p;
const int clipped_prob = p | ((255 - p) >> 23) | (p == 0);
return (aom_prob)clipped_prob;
}
}
static INLINE aom_prob get_binary_prob(unsigned int n0, unsigned int n1) {
const unsigned int den = n0 + n1;
if (den == 0) return 128u;
return get_prob(n0, den);
}
/* This function assumes prob1 and prob2 are already within [1,255] range. */
static INLINE aom_prob weighted_prob(int prob1, int prob2, int factor) {
return ROUND_POWER_OF_TWO(prob1 * (256 - factor) + prob2 * factor, 8);
}
static INLINE aom_prob merge_probs(aom_prob pre_prob, const unsigned int ct[2],
unsigned int count_sat,
unsigned int max_update_factor) {
const aom_prob prob = get_binary_prob(ct[0], ct[1]);
const unsigned int count = AOMMIN(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 aom_prob mode_mv_merge_probs(aom_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 = AOMMIN(den, MODE_MV_COUNT_SAT);
const unsigned int factor = count_to_update_factor[count];
const aom_prob prob = get_prob(ct[0], den);
return weighted_prob(pre_prob, prob, factor);
}
}
void aom_tree_merge_probs(const aom_tree_index *tree, const aom_prob *pre_probs,
const unsigned int *counts, aom_prob *probs);
int tree_to_cdf(const aom_tree_index *tree, const aom_prob *probs,
aom_tree_index root, aom_cdf_prob *cdf, aom_tree_index *ind,
int *pth, int *len);
static INLINE void av1_tree_to_cdf(const aom_tree_index *tree,
const aom_prob *probs, aom_cdf_prob *cdf) {
aom_tree_index index[16];
int path[16];
int dist[16];
tree_to_cdf(tree, probs, 0, cdf, index, path, dist);
}
#define av1_tree_to_cdf_1D(tree, probs, cdf, u) \
do { \
int i; \
for (i = 0; i < u; i++) { \
av1_tree_to_cdf(tree, probs[i], cdf[i]); \
} \
} while (0)
#define av1_tree_to_cdf_2D(tree, probs, cdf, v, u) \
do { \
int j; \
int i; \
for (j = 0; j < v; j++) { \
for (i = 0; i < u; i++) { \
av1_tree_to_cdf(tree, probs[j][i], cdf[j][i]); \
} \
} \
} while (0)
void av1_indices_from_tree(int *ind, int *inv, const aom_tree_index *tree);
#if CONFIG_EC_ADAPT
static INLINE void update_cdf(aom_cdf_prob *cdf, int val, int nsymbs) {
const int rate = 4 + (cdf[nsymbs] > 31) + get_msb(nsymbs);
const int rate2 = 5;
int i, tmp;
int diff;
#if 1
const int tmp0 = 1 << rate2;
tmp = AOM_ICDF(tmp0);
diff = ((CDF_PROB_TOP - (nsymbs << rate2)) >> rate) << rate;
// Single loop (faster)
#if !CONFIG_ANS && CONFIG_EC_SMALLMUL
for (i = 0; i < nsymbs - 1; ++i, tmp -= tmp0) {
tmp -= (i == val ? diff : 0);
cdf[i] += ((tmp - cdf[i]) >> rate);
}
#else
for (i = 0; i < nsymbs - 1; ++i, tmp += tmp0) {
tmp += (i == val ? diff : 0);
cdf[i] -= ((cdf[i] - tmp) >> rate);
}
#endif
#else
for (i = 0; i < nsymbs; ++i) {
tmp = (i + 1) << rate2;
cdf[i] -= ((cdf[i] - tmp) >> rate);
}
diff = CDF_PROB_TOP - cdf[nsymbs - 1];
for (i = val; i < nsymbs; ++i) {
cdf[i] += diff;
}
#endif
cdf[nsymbs] += (cdf[nsymbs] < 32);
}
#endif
#ifdef __cplusplus
} // extern "C"
#endif
#endif // AOM_DSP_PROB_H_