vp9_entropy.h 7.5 KB
Newer Older
John Koleszar's avatar
John Koleszar committed
1
/*
2
 *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
John Koleszar's avatar
John Koleszar committed
3
 *
4
 *  Use of this source code is governed by a BSD-style license
5
6
 *  that can be found in the LICENSE file in the root of the source
 *  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.
John Koleszar's avatar
John Koleszar committed
9
10
 */

11
12
#ifndef VP9_COMMON_VP9_ENTROPY_H_
#define VP9_COMMON_VP9_ENTROPY_H_
John Koleszar's avatar
John Koleszar committed
13

14
#include "vpx/vpx_integer.h"
15

16
17
#include "vp9/common/vp9_blockd.h"
#include "vp9/common/vp9_common.h"
18
19
#include "vp9/common/vp9_scan.h"
#include "vp9/common/vp9_treecoder.h"
Jim Bankoski's avatar
Jim Bankoski committed
20
#include "vp9/common/vp9_entropymode.h"
21

22
23
#define DIFF_UPDATE_PROB 252

John Koleszar's avatar
John Koleszar committed
24
25
/* Coefficient token alphabet */

26
27
28
29
30
31
32
#define ZERO_TOKEN              0       /* 0         Extra Bits 0+0 */
#define ONE_TOKEN               1       /* 1         Extra Bits 0+1 */
#define TWO_TOKEN               2       /* 2         Extra Bits 0+1 */
#define THREE_TOKEN             3       /* 3         Extra Bits 0+1 */
#define FOUR_TOKEN              4       /* 4         Extra Bits 0+1 */
#define DCT_VAL_CATEGORY1       5       /* 5-6       Extra Bits 1+1 */
#define DCT_VAL_CATEGORY2       6       /* 7-10      Extra Bits 2+1 */
33
34
35
#define DCT_VAL_CATEGORY3       7       /* 11-18     Extra Bits 3+1 */
#define DCT_VAL_CATEGORY4       8       /* 19-34     Extra Bits 4+1 */
#define DCT_VAL_CATEGORY5       9       /* 35-66     Extra Bits 5+1 */
36
#define DCT_VAL_CATEGORY6       10      /* 67+       Extra Bits 14+1 */
37
#define DCT_EOB_TOKEN           11      /* EOB       Extra Bits 0+0 */
38
39
#define MAX_ENTROPY_TOKENS      12
#define ENTROPY_NODES           11
40
#define EOSB_TOKEN              127     /* Not signalled, encoder only */
John Koleszar's avatar
John Koleszar committed
41

42
43
#define INTER_MODE_CONTEXTS     7

44
45
46
extern DECLARE_ALIGNED(16, const uint8_t,
                       vp9_pt_energy_class[MAX_ENTROPY_TOKENS]);

47
extern const vp9_tree_index vp9_coef_tree[TREE_SIZE(MAX_ENTROPY_TOKENS)];
John Koleszar's avatar
John Koleszar committed
48

49
50
51
#define DCT_EOB_MODEL_TOKEN     3      /* EOB       Extra Bits 0+0 */
extern const vp9_tree_index vp9_coefmodel_tree[];

52
extern struct vp9_token vp9_coef_encodings[MAX_ENTROPY_TOKENS];
John Koleszar's avatar
John Koleszar committed
53

John Koleszar's avatar
John Koleszar committed
54
typedef struct {
55
  const vp9_tree_index *tree;
56
  const vp9_prob *prob;
57
  int len;
John Koleszar's avatar
John Koleszar committed
58
  int base_val;
59
} vp9_extra_bit;
John Koleszar's avatar
John Koleszar committed
60

61
62
// indexed by token value
extern const vp9_extra_bit vp9_extra_bits[MAX_ENTROPY_TOKENS];
John Koleszar's avatar
John Koleszar committed
63
64

#define MAX_PROB                255
65
#define DCT_MAX_VALUE           16384
John Koleszar's avatar
John Koleszar committed
66
67
68

/* Coefficients are predicted via a 3-dimensional probability table. */

69
/* Outside dimension.  0 = Y with DC, 1 = UV */
70
71
#define BLOCK_TYPES 2
#define REF_TYPES 2  // intra=0, inter=1
72

73
74
75
76
77
78
79
80
81
82
/* Middle dimension reflects the coefficient position within the transform. */
#define COEF_BANDS 6

/* Inside dimension is measure of nearby complexity, that reflects the energy
   of nearby coefficients are nonzero.  For the first coefficient (DC, unless
   block type is 0), we look at the (already encoded) blocks above and to the
   left of the current block.  The context index is then the number (0,1,or 2)
   of these blocks having nonzero coefficients.
   After decoding a coefficient, the measure is determined by the size of the
   most recently decoded coefficient.
John Koleszar's avatar
John Koleszar committed
83
84
85
86
87
88
89
90
91
   Note that the intuitive meaning of this measure changes as coefficients
   are decoded, e.g., prior to the first token, a zero means that my neighbors
   are empty while, after the first token, because of the use of end-of-block,
   a zero means we just decoded a zero and hence guarantees that a non-zero
   coefficient will appear later in this block.  However, this shift
   in meaning is perfectly OK because our context depends also on the
   coefficient band (and since zigzag positions 0, 1, and 2 are in
   distinct bands). */

92
#define PREV_COEF_CONTEXTS          6
93

94
// #define ENTROPY_STATS
95

96
typedef unsigned int vp9_coeff_count[REF_TYPES][COEF_BANDS][PREV_COEF_CONTEXTS]
97
                                    [MAX_ENTROPY_TOKENS];
98
typedef unsigned int vp9_coeff_stats[REF_TYPES][COEF_BANDS][PREV_COEF_CONTEXTS]
99
100
                                    [ENTROPY_NODES][2];

101
102
#define SUBEXP_PARAM                4   /* Subexponential code parameter */
#define MODULUS_PARAM               13  /* Modulus parameter */
103

104
struct VP9Common;
105
void vp9_default_coef_probs(struct VP9Common *cm);
106

107
void vp9_coef_tree_initialize();
108
void vp9_adapt_coef_probs(struct VP9Common *cm);
Daniel Kang's avatar
Daniel Kang committed
109

110
static INLINE void reset_skip_context(MACROBLOCKD *xd, BLOCK_SIZE bsize) {
111
112
  int i;
  for (i = 0; i < MAX_MB_PLANE; i++) {
113
    struct macroblockd_plane *const pd = &xd->plane[i];
114
    const BLOCK_SIZE plane_bsize = get_plane_block_size(bsize, pd);
115
116
117
118
    vpx_memset(pd->above_context, 0, sizeof(ENTROPY_CONTEXT) *
                   num_4x4_blocks_wide_lookup[plane_bsize]);
    vpx_memset(pd->left_context, 0, sizeof(ENTROPY_CONTEXT) *
                   num_4x4_blocks_high_lookup[plane_bsize]);
119
  }
120
121
}

Paul Wilkins's avatar
Paul Wilkins committed
122
123
// This is the index in the scan order beyond which all coefficients for
// 8x8 transform and above are in the top band.
124
// This macro is currently unused but may be used by certain implementations
Paul Wilkins's avatar
Paul Wilkins committed
125
126
#define MAXBAND_INDEX 21

127
128
129
130
131
132
133
extern const uint8_t vp9_coefband_trans_8x8plus[1024];
extern const uint8_t vp9_coefband_trans_4x4[16];

static const uint8_t *get_band_translate(TX_SIZE tx_size) {
  return tx_size == TX_4X4 ? vp9_coefband_trans_4x4
                           : vp9_coefband_trans_8x8plus;
}
Paul Wilkins's avatar
Paul Wilkins committed
134

135
136
// 128 lists of probabilities are stored for the following ONE node probs:
// 1, 3, 5, 7, ..., 253, 255
137
138
// In between probabilities are interpolated linearly

139
#define COEFPROB_MODELS             128
140

141
#define UNCONSTRAINED_NODES         3
142

143
#define PIVOT_NODE                  2   // which node is pivot
144

Jim Bankoski's avatar
Jim Bankoski committed
145
146
147
#define MODEL_NODES (ENTROPY_NODES - UNCONSTRAINED_NODES)
extern const vp9_prob vp9_pareto8_full[255][MODEL_NODES];

148
typedef vp9_prob vp9_coeff_probs_model[REF_TYPES][COEF_BANDS]
149
150
151
152
153
154
155
                                      [PREV_COEF_CONTEXTS]
                                      [UNCONSTRAINED_NODES];

typedef unsigned int vp9_coeff_count_model[REF_TYPES][COEF_BANDS]
                                          [PREV_COEF_CONTEXTS]
                                          [UNCONSTRAINED_NODES + 1];

156
void vp9_model_to_full_probs(const vp9_prob *model, vp9_prob *full);
157

158
159
static int get_entropy_context(TX_SIZE tx_size, const ENTROPY_CONTEXT *a,
                                                const ENTROPY_CONTEXT *l) {
160
  ENTROPY_CONTEXT above_ec = 0, left_ec = 0;
161

162
163
164
165
166
167
  switch (tx_size) {
    case TX_4X4:
      above_ec = a[0] != 0;
      left_ec = l[0] != 0;
      break;
    case TX_8X8:
168
169
      above_ec = !!*(const uint16_t *)a;
      left_ec  = !!*(const uint16_t *)l;
170
171
      break;
    case TX_16X16:
172
173
      above_ec = !!*(const uint32_t *)a;
      left_ec  = !!*(const uint32_t *)l;
174
175
      break;
    case TX_32X32:
176
177
      above_ec = !!*(const uint64_t *)a;
      left_ec  = !!*(const uint64_t *)l;
178
179
180
181
182
183
184
185
      break;
    default:
      assert(!"Invalid transform size.");
  }

  return combine_entropy_contexts(above_ec, left_ec);
}

186
187
188
static void get_scan(const MACROBLOCKD *xd, TX_SIZE tx_size,
                     PLANE_TYPE type, int block_idx,
                     const int16_t **scan, const int16_t **scan_nb) {
189
190
191
192
193
194
195
196
197
198
  const MODE_INFO *const mi = xd->mi_8x8[0];
  const MB_MODE_INFO *const mbmi = &mi->mbmi;
  const scan_order *so;

  if (is_inter_block(mbmi) || type != PLANE_TYPE_Y_WITH_DC || xd->lossless) {
    so = &inter_scan_orders[tx_size];
  } else {
    const MB_PREDICTION_MODE mode =
        mbmi->sb_type < BLOCK_8X8 ? mi->bmi[block_idx].as_mode : mbmi->mode;
    so = &intra_scan_orders[tx_size][mode];
199
  }
200
201
  *scan = so->scan;
  *scan_nb = so->neighbors;
202
203
}

204
#endif  // VP9_COMMON_VP9_ENTROPY_H_