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+/*
+ * 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_