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, short, vp8_default_zig_zag_mask[16]);
  40
  41 const int vp8_mb_feature_data_bits[MB_LVL_MAX] = {7, 6};
  42
  43 /* Array indices are identical to previously-existing CONTEXT_NODE indices */
  44
  45 const vp8_tree_index vp8_coef_tree[ 22] =     /* corresponding _CONTEXT_NODEs */
  46 {
  47     -DCT_EOB_TOKEN, 2,                             /* 0 = EOB */
  48     -ZERO_TOKEN, 4,                               /* 1 = ZERO */
  49     -ONE_TOKEN, 6,                               /* 2 = ONE */
  50     8, 12,                                      /* 3 = LOW_VAL */
  51     -TWO_TOKEN, 10,                            /* 4 = TWO */
  52     -THREE_TOKEN, -FOUR_TOKEN,                /* 5 = THREE */
  53     14, 16,                                    /* 6 = HIGH_LOW */
  54     -DCT_VAL_CATEGORY1, -DCT_VAL_CATEGORY2,   /* 7 = CAT_ONE */
  55     18, 20,                                   /* 8 = CAT_THREEFOUR */
  56     -DCT_VAL_CATEGORY3, -DCT_VAL_CATEGORY4,  /* 9 = CAT_THREE */
  57     -DCT_VAL_CATEGORY5, -DCT_VAL_CATEGORY6   /* 10 = CAT_FIVE */
  58 };
  59
  60 struct vp8_token_struct vp8_coef_encodings[vp8_coef_tokens];
  61
  62 /* Trees for extra bits.  Probabilities are constant and
  63    do not depend on previously encoded bits */
  64
  65 static const Prob Pcat1[] = { 159};
  66 static const Prob Pcat2[] = { 165, 145};
  67 static const Prob Pcat3[] = { 173, 148, 140};
  68 static const Prob Pcat4[] = { 176, 155, 140, 135};
  69 static const Prob Pcat5[] = { 180, 157, 141, 134, 130};
  70 static const Prob Pcat6[] =
  71 { 254, 254, 243, 230, 196, 177, 153, 140, 133, 130, 129};
  72
  73 static vp8_tree_index cat1[2], cat2[4], cat3[6], cat4[8], cat5[10], cat6[22];
  74
  75 void vp8_init_scan_order_mask()
  76 {
  77     int i;
  78
  79     for (i = 0; i < 16; i++)
  80     {
  81         vp8_default_zig_zag_mask[vp8_default_zig_zag1d[i]] = 1 << i;
  82     }
  83
  84 }
  85
  86 static void init_bit_tree(vp8_tree_index *p, int n)
  87 {
  88     int i = 0;
  89
  90     while (++i < n)
  91     {
  92         p[0] = p[1] = i << 1;
  93         p += 2;
  94     }
  95
  96     p[0] = p[1] = 0;
  97 }
  98
  99 static void init_bit_trees()
 100 {
 101     init_bit_tree(cat1, 1);
 102     init_bit_tree(cat2, 2);
 103     init_bit_tree(cat3, 3);
 104     init_bit_tree(cat4, 4);
 105     init_bit_tree(cat5, 5);
 106     init_bit_tree(cat6, 11);
 107 }
 108
 109
 110 static vp8bc_index_t bcc1[1], bcc2[2], bcc3[3], bcc4[4], bcc5[5], bcc6[11];
 111
 112 vp8_extra_bit_struct vp8_extra_bits[12] =
 113 {
 114     { 0, 0, 0, 0, 0},
 115     { 0, 0, 0, 0, 1},
 116     { 0, 0, 0, 0, 2},
 117     { 0, 0, 0, 0, 3},
 118     { 0, 0, 0, 0, 4},
 119     { cat1, Pcat1, bcc1, 1, 5},
 120     { cat2, Pcat2, bcc2, 2, 7},
 121     { cat3, Pcat3, bcc3, 3, 11},
 122     { cat4, Pcat4, bcc4, 4, 19},
 123     { cat5, Pcat5, bcc5, 5, 35},
 124     { cat6, Pcat6, bcc6, 11, 67},
 125     { 0, 0, 0, 0, 0}
 126 };
 127 #include "defaultcoefcounts.h"
 128
 129 void vp8_default_coef_probs(VP8_COMMON *pc)
 130 {
 131     int h = 0;
 132
 133     do
 134     {
 135         int i = 0;
 136
 137         do
 138         {
 139             int k = 0;
 140
 141             do
 142             {
 143                 unsigned int branch_ct [vp8_coef_tokens-1] [2];
 144                 vp8_tree_probs_from_distribution(
 145                     vp8_coef_tokens, vp8_coef_encodings, vp8_coef_tree,
 146                     pc->fc.coef_probs [h][i][k], branch_ct, default_coef_counts [h][i][k],
 147                     256, 1);
 148
 149             }
 150             while (++k < PREV_COEF_CONTEXTS);
 151         }
 152         while (++i < COEF_BANDS);
 153     }
 154     while (++h < BLOCK_TYPES);
 155 }
 156
 157
 158 void vp8_coef_tree_initialize()
 159 {
 160     init_bit_trees();
 161     vp8_tokens_from_tree(vp8_coef_encodings, vp8_coef_tree);
 162 }