text: /*
   *  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>
  
  #define INLINE __inline
  
  #include <stdint.h>
  #include "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);
  }
  