vp8/common/entropy.c

   1 /*
   2  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
   3  *
   4  *  Use of this source code is governed by a BSD-style license
   5  *  that can be found in the LICENSE file in the root of the source
   6  *  tree. An additional intellectual property rights grant can be found
   7  *  in the file PATENTS.  All contributing project authors may
   8  *  be found in the AUTHORS file in the root of the source tree.
   9  */
  10
  11
  12 #include <stdio.h>
  13
  14 #include "entropy.h"
  15 #include "string.h"
  16 #include "blockd.h"
  17 #include "onyxc_int.h"
  18
  19 #define uchar unsigned char     /* typedefs can clash */
  20 #define uint  unsigned int
  21
  22 typedef const uchar cuchar;
  23 typedef const uint cuint;
  24
  25 typedef vp8_prob Prob;
  26
  27 #include "coefupdateprobs.h"
  28
  29 DECLARE_ALIGNED(16, cuchar, vp8_coef_bands[16]) = { 0, 1, 2, 3, 6, 4, 5, 6, 6, 6, 6, 6, 6, 6, 6, 7};
  30 DECLARE_ALIGNED(16, cuchar, vp8_prev_token_class[MAX_ENTROPY_TOKENS]) = { 0, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 0};
  31 DECLARE_ALIGNED(16, const int, vp8_default_zig_zag1d[16]) =
  32 {
  33     0,  1,  4,  8,
  34     5,  2,  3,  6,
  35     9, 12, 13, 10,
  36     7, 11, 14, 15,
  37 };
  38
  39 DECLARE_ALIGNED(16, const short, vp8_default_inv_zig_zag[16]) =
  40 {
  41     1,  2,  6,  7,
  42     3,  5,  8, 13,
  43     4,  9, 12, 14,
  44    10, 11, 15, 16
  45 };
  46
  47 DECLARE_ALIGNED(16, short, vp8_default_zig_zag_mask[16]);
  48
  49 const int vp8_mb_feature_data_bits[MB_LVL_MAX] = {7, 6};
  50
  51 /* Array indices are identical to previously-existing CONTEXT_NODE indices */
  52
  53 const vp8_tree_index vp8_coef_tree[ 22] =     /* corresponding _CONTEXT_NODEs */
  54 {
  55     -DCT_EOB_TOKEN, 2,                             /* 0 = EOB */
  56     -ZERO_TOKEN, 4,                               /* 1 = ZERO */
  57     -ONE_TOKEN, 6,                               /* 2 = ONE */
  58     8, 12,                                      /* 3 = LOW_VAL */
  59     -TWO_TOKEN, 10,                            /* 4 = TWO */
  60     -THREE_TOKEN, -FOUR_TOKEN,                /* 5 = THREE */
  61     14, 16,                                    /* 6 = HIGH_LOW */
  62     -DCT_VAL_CATEGORY1, -DCT_VAL_CATEGORY2,   /* 7 = CAT_ONE */
  63     18, 20,                                   /* 8 = CAT_THREEFOUR */
  64     -DCT_VAL_CATEGORY3, -DCT_VAL_CATEGORY4,  /* 9 = CAT_THREE */
  65     -DCT_VAL_CATEGORY5, -DCT_VAL_CATEGORY6   /* 10 = CAT_FIVE */
  66 };
  67
  68 struct vp8_token_struct vp8_coef_encodings[vp8_coef_tokens];
  69
  70 /* Trees for extra bits.  Probabilities are constant and
  71    do not depend on previously encoded bits */
  72
  73 static const Prob Pcat1[] = { 159};
  74 static const Prob Pcat2[] = { 165, 145};
  75 static const Prob Pcat3[] = { 173, 148, 140};
  76 static const Prob Pcat4[] = { 176, 155, 140, 135};
  77 static const Prob Pcat5[] = { 180, 157, 141, 134, 130};
  78 static const Prob Pcat6[] =
  79 { 254, 254, 243, 230, 196, 177, 153, 140, 133, 130, 129};
  80
  81 static vp8_tree_index cat1[2], cat2[4], cat3[6], cat4[8], cat5[10], cat6[22];
  82
  83 void vp8_init_scan_order_mask()
  84 {
  85     int i;
  86
  87     for (i = 0; i < 16; i++)
  88     {
  89         vp8_default_zig_zag_mask[vp8_default_zig_zag1d[i]] = 1 << i;
  90     }
  91
  92 }
  93
  94 static void init_bit_tree(vp8_tree_index *p, int n)
  95 {
  96     int i = 0;
  97
  98     while (++i < n)
  99     {
 100         p[0] = p[1] = i << 1;
 101         p += 2;
 102     }
 103
 104     p[0] = p[1] = 0;
 105 }
 106
 107 static void init_bit_trees()
 108 {
 109     init_bit_tree(cat1, 1);
 110     init_bit_tree(cat2, 2);
 111     init_bit_tree(cat3, 3);
 112     init_bit_tree(cat4, 4);
 113     init_bit_tree(cat5, 5);
 114     init_bit_tree(cat6, 11);
 115 }
 116
 117 vp8_extra_bit_struct vp8_extra_bits[12] =
 118 {
 119     { 0, 0, 0, 0},
 120     { 0, 0, 0, 1},
 121     { 0, 0, 0, 2},
 122     { 0, 0, 0, 3},
 123     { 0, 0, 0, 4},
 124     { cat1, Pcat1, 1, 5},
 125     { cat2, Pcat2, 2, 7},
 126     { cat3, Pcat3, 3, 11},
 127     { cat4, Pcat4, 4, 19},
 128     { cat5, Pcat5, 5, 35},
 129     { cat6, Pcat6, 11, 67},
 130     { 0, 0, 0, 0}
 131 };
 132 #include "defaultcoefcounts.h"
 133
 134 void vp8_default_coef_probs(VP8_COMMON *pc)
 135 {
 136     int h = 0;
 137
 138     do
 139     {
 140         int i = 0;
 141
 142         do
 143         {
 144             int k = 0;
 145
 146             do
 147             {
 148                 unsigned int branch_ct [vp8_coef_tokens-1] [2];
 149                 vp8_tree_probs_from_distribution(
 150                     vp8_coef_tokens, vp8_coef_encodings, vp8_coef_tree,
 151                     pc->fc.coef_probs [h][i][k], branch_ct, default_coef_counts [h][i][k],
 152                     256, 1);
 153
 154             }
 155             while (++k < PREV_COEF_CONTEXTS);
 156         }
 157         while (++i < COEF_BANDS);
 158     }
 159     while (++h < BLOCK_TYPES);
 160 }
 161
 162
 163 void vp8_coef_tree_initialize()
 164 {
 165     init_bit_trees();
 166     vp8_tokens_from_tree(vp8_coef_encodings, vp8_coef_tree);
 167 }