1 /*
2 * Copyright (c) 2016, Alliance for Open Media. All rights reserved
3 *
4 * This source code is subject to the terms of the BSD 2 Clause License and
5 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
6 * was not distributed with this source code in the LICENSE file, you can
7 * obtain it at www.aomedia.org/license/software. If the Alliance for Open
8 * Media Patent License 1.0 was not distributed with this source code in the
9 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
10 */
11
12 #include <math.h>
13 #include <stdlib.h>
14
15 #include "av1/encoder/cost.h"
16 #include "av1/encoder/palette.h"
17 #include "av1/encoder/random.h"
18
19 #define AV1_K_MEANS_DIM 1
20 #include "av1/encoder/k_means_template.h"
21 #undef AV1_K_MEANS_DIM
22 #define AV1_K_MEANS_DIM 2
23 #include "av1/encoder/k_means_template.h"
24 #undef AV1_K_MEANS_DIM
25
int_comparer(const void * a,const void * b)26 static int int_comparer(const void *a, const void *b) {
27 return (*(int *)a - *(int *)b);
28 }
29
av1_remove_duplicates(int * centroids,int num_centroids)30 int av1_remove_duplicates(int *centroids, int num_centroids) {
31 int num_unique; // number of unique centroids
32 int i;
33 qsort(centroids, num_centroids, sizeof(*centroids), int_comparer);
34 // Remove duplicates.
35 num_unique = 1;
36 for (i = 1; i < num_centroids; ++i) {
37 if (centroids[i] != centroids[i - 1]) { // found a new unique centroid
38 centroids[num_unique++] = centroids[i];
39 }
40 }
41 return num_unique;
42 }
43
delta_encode_cost(const int * colors,int num,int bit_depth,int min_val)44 static int delta_encode_cost(const int *colors, int num, int bit_depth,
45 int min_val) {
46 if (num <= 0) return 0;
47 int bits_cost = bit_depth;
48 if (num == 1) return bits_cost;
49 bits_cost += 2;
50 int max_delta = 0;
51 int deltas[PALETTE_MAX_SIZE];
52 const int min_bits = bit_depth - 3;
53 for (int i = 1; i < num; ++i) {
54 const int delta = colors[i] - colors[i - 1];
55 deltas[i - 1] = delta;
56 assert(delta >= min_val);
57 if (delta > max_delta) max_delta = delta;
58 }
59 int bits_per_delta = AOMMAX(av1_ceil_log2(max_delta + 1 - min_val), min_bits);
60 assert(bits_per_delta <= bit_depth);
61 int range = (1 << bit_depth) - colors[0] - min_val;
62 for (int i = 0; i < num - 1; ++i) {
63 bits_cost += bits_per_delta;
64 range -= deltas[i];
65 bits_per_delta = AOMMIN(bits_per_delta, av1_ceil_log2(range));
66 }
67 return bits_cost;
68 }
69
av1_index_color_cache(const uint16_t * color_cache,int n_cache,const uint16_t * colors,int n_colors,uint8_t * cache_color_found,int * out_cache_colors)70 int av1_index_color_cache(const uint16_t *color_cache, int n_cache,
71 const uint16_t *colors, int n_colors,
72 uint8_t *cache_color_found, int *out_cache_colors) {
73 if (n_cache <= 0) {
74 for (int i = 0; i < n_colors; ++i) out_cache_colors[i] = colors[i];
75 return n_colors;
76 }
77 memset(cache_color_found, 0, n_cache * sizeof(*cache_color_found));
78 int n_in_cache = 0;
79 int in_cache_flags[PALETTE_MAX_SIZE];
80 memset(in_cache_flags, 0, sizeof(in_cache_flags));
81 for (int i = 0; i < n_cache && n_in_cache < n_colors; ++i) {
82 for (int j = 0; j < n_colors; ++j) {
83 if (colors[j] == color_cache[i]) {
84 in_cache_flags[j] = 1;
85 cache_color_found[i] = 1;
86 ++n_in_cache;
87 break;
88 }
89 }
90 }
91 int j = 0;
92 for (int i = 0; i < n_colors; ++i)
93 if (!in_cache_flags[i]) out_cache_colors[j++] = colors[i];
94 assert(j == n_colors - n_in_cache);
95 return j;
96 }
97
av1_get_palette_delta_bits_v(const PALETTE_MODE_INFO * const pmi,int bit_depth,int * zero_count,int * min_bits)98 int av1_get_palette_delta_bits_v(const PALETTE_MODE_INFO *const pmi,
99 int bit_depth, int *zero_count,
100 int *min_bits) {
101 const int n = pmi->palette_size[1];
102 const int max_val = 1 << bit_depth;
103 int max_d = 0;
104 *min_bits = bit_depth - 4;
105 *zero_count = 0;
106 for (int i = 1; i < n; ++i) {
107 const int delta = pmi->palette_colors[2 * PALETTE_MAX_SIZE + i] -
108 pmi->palette_colors[2 * PALETTE_MAX_SIZE + i - 1];
109 const int v = abs(delta);
110 const int d = AOMMIN(v, max_val - v);
111 if (d > max_d) max_d = d;
112 if (d == 0) ++(*zero_count);
113 }
114 return AOMMAX(av1_ceil_log2(max_d + 1), *min_bits);
115 }
116
av1_palette_color_cost_y(const PALETTE_MODE_INFO * const pmi,uint16_t * color_cache,int n_cache,int bit_depth)117 int av1_palette_color_cost_y(const PALETTE_MODE_INFO *const pmi,
118 uint16_t *color_cache, int n_cache,
119 int bit_depth) {
120 const int n = pmi->palette_size[0];
121 int out_cache_colors[PALETTE_MAX_SIZE];
122 uint8_t cache_color_found[2 * PALETTE_MAX_SIZE];
123 const int n_out_cache =
124 av1_index_color_cache(color_cache, n_cache, pmi->palette_colors, n,
125 cache_color_found, out_cache_colors);
126 const int total_bits =
127 n_cache + delta_encode_cost(out_cache_colors, n_out_cache, bit_depth, 1);
128 return av1_cost_literal(total_bits);
129 }
130
av1_palette_color_cost_uv(const PALETTE_MODE_INFO * const pmi,uint16_t * color_cache,int n_cache,int bit_depth)131 int av1_palette_color_cost_uv(const PALETTE_MODE_INFO *const pmi,
132 uint16_t *color_cache, int n_cache,
133 int bit_depth) {
134 const int n = pmi->palette_size[1];
135 int total_bits = 0;
136 // U channel palette color cost.
137 int out_cache_colors[PALETTE_MAX_SIZE];
138 uint8_t cache_color_found[2 * PALETTE_MAX_SIZE];
139 const int n_out_cache = av1_index_color_cache(
140 color_cache, n_cache, pmi->palette_colors + PALETTE_MAX_SIZE, n,
141 cache_color_found, out_cache_colors);
142 total_bits +=
143 n_cache + delta_encode_cost(out_cache_colors, n_out_cache, bit_depth, 0);
144
145 // V channel palette color cost.
146 int zero_count = 0, min_bits_v = 0;
147 const int bits_v =
148 av1_get_palette_delta_bits_v(pmi, bit_depth, &zero_count, &min_bits_v);
149 const int bits_using_delta =
150 2 + bit_depth + (bits_v + 1) * (n - 1) - zero_count;
151 const int bits_using_raw = bit_depth * n;
152 total_bits += 1 + AOMMIN(bits_using_delta, bits_using_raw);
153 return av1_cost_literal(total_bits);
154 }
155