ref: c3312cb6cafad85adf764e75d465013a22d1840f
dir: /vp9/encoder/vp9_cost.c/
/*
* Copyright (c) 2014 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.
*/
#include <assert.h>
#include "vp9/encoder/vp9_cost.h"
/* round(-log2(i/256.) * (1 << VP9_PROB_COST_SHIFT))
Begins with a bogus entry for simpler addressing. */
const uint16_t vp9_prob_cost[256] = {
4096, 4096, 3584, 3284, 3072, 2907, 2772, 2659, 2560, 2473, 2395, 2325, 2260,
2201, 2147, 2096, 2048, 2003, 1961, 1921, 1883, 1847, 1813, 1780, 1748, 1718,
1689, 1661, 1635, 1609, 1584, 1559, 1536, 1513, 1491, 1470, 1449, 1429, 1409,
1390, 1371, 1353, 1335, 1318, 1301, 1284, 1268, 1252, 1236, 1221, 1206, 1192,
1177, 1163, 1149, 1136, 1123, 1110, 1097, 1084, 1072, 1059, 1047, 1036, 1024,
1013, 1001, 990, 979, 968, 958, 947, 937, 927, 917, 907, 897, 887,
878, 868, 859, 850, 841, 832, 823, 814, 806, 797, 789, 780, 772,
764, 756, 748, 740, 732, 724, 717, 709, 702, 694, 687, 680, 673,
665, 658, 651, 644, 637, 631, 624, 617, 611, 604, 598, 591, 585,
578, 572, 566, 560, 554, 547, 541, 535, 530, 524, 518, 512, 506,
501, 495, 489, 484, 478, 473, 467, 462, 456, 451, 446, 441, 435,
430, 425, 420, 415, 410, 405, 400, 395, 390, 385, 380, 375, 371,
366, 361, 356, 352, 347, 343, 338, 333, 329, 324, 320, 316, 311,
307, 302, 298, 294, 289, 285, 281, 277, 273, 268, 264, 260, 256,
252, 248, 244, 240, 236, 232, 228, 224, 220, 216, 212, 209, 205,
201, 197, 194, 190, 186, 182, 179, 175, 171, 168, 164, 161, 157,
153, 150, 146, 143, 139, 136, 132, 129, 125, 122, 119, 115, 112,
109, 105, 102, 99, 95, 92, 89, 86, 82, 79, 76, 73, 70,
66, 63, 60, 57, 54, 51, 48, 45, 42, 38, 35, 32, 29,
26, 23, 20, 18, 15, 12, 9, 6, 3
};
static void cost(int *costs, vpx_tree tree, const vpx_prob *probs, int i,
int c) {
const vpx_prob prob = probs[i / 2];
int b;
assert(prob != 0);
for (b = 0; b <= 1; ++b) {
const int cc = c + vp9_cost_bit(prob, b);
const vpx_tree_index ii = tree[i + b];
if (ii <= 0)
costs[-ii] = cc;
else
cost(costs, tree, probs, ii, cc);
}
}
void vp9_cost_tokens(int *costs, const vpx_prob *probs, vpx_tree tree) {
cost(costs, tree, probs, 0, 0);
}
void vp9_cost_tokens_skip(int *costs, const vpx_prob *probs, vpx_tree tree) {
assert(tree[0] <= 0 && tree[1] > 0);
costs[-tree[0]] = vp9_cost_bit(probs[0], 0);
cost(costs, tree, probs, 2, 0);
}