vp9_entropy.h 7.79 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"
20

21
22
#define DIFF_UPDATE_PROB 252

John Koleszar's avatar
John Koleszar committed
23
24
/* Coefficient token alphabet */

25
26
27
28
29
30
31
#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 */
32
33
34
#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 */
35
#define DCT_VAL_CATEGORY6       10      /* 67+       Extra Bits 14+1 */
36
#define DCT_EOB_TOKEN           11      /* EOB       Extra Bits 0+0 */
37
38
#define MAX_ENTROPY_TOKENS      12
#define ENTROPY_NODES           11
39
#define EOSB_TOKEN              127     /* Not signalled, encoder only */
John Koleszar's avatar
John Koleszar committed
40

41
42
#define INTER_MODE_CONTEXTS     7

43
44
45
extern DECLARE_ALIGNED(16, const uint8_t,
                       vp9_pt_energy_class[MAX_ENTROPY_TOKENS]);

46
extern const vp9_tree_index vp9_coef_tree[];
John Koleszar's avatar
John Koleszar committed
47

48
49
50
#define DCT_EOB_MODEL_TOKEN     3      /* EOB       Extra Bits 0+0 */
extern const vp9_tree_index vp9_coefmodel_tree[];

51
extern struct vp9_token vp9_coef_encodings[MAX_ENTROPY_TOKENS];
John Koleszar's avatar
John Koleszar committed
52

John Koleszar's avatar
John Koleszar committed
53
typedef struct {
54
55
  vp9_tree_p tree;
  const vp9_prob *prob;
56
  int len;
John Koleszar's avatar
John Koleszar committed
57
  int base_val;
58
} vp9_extra_bit;
John Koleszar's avatar
John Koleszar committed
59

60
extern const vp9_extra_bit vp9_extra_bits[12];    /* indexed by token value */
John Koleszar's avatar
John Koleszar committed
61
62

#define MAX_PROB                255
63
#define DCT_MAX_VALUE           16384
John Koleszar's avatar
John Koleszar committed
64
65
66

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

67
/* Outside dimension.  0 = Y with DC, 1 = UV */
68
69
#define BLOCK_TYPES 2
#define REF_TYPES 2  // intra=0, inter=1
70

71
72
73
74
75
76
77
78
79
80
/* 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
81
82
83
84
85
86
87
88
89
   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). */

90
#define PREV_COEF_CONTEXTS          6
91

92
// #define ENTROPY_STATS
93

94
typedef unsigned int vp9_coeff_count[REF_TYPES][COEF_BANDS][PREV_COEF_CONTEXTS]
95
                                    [MAX_ENTROPY_TOKENS];
96
typedef unsigned int vp9_coeff_stats[REF_TYPES][COEF_BANDS][PREV_COEF_CONTEXTS]
97
                                    [ENTROPY_NODES][2];
98
typedef vp9_prob vp9_coeff_probs[REF_TYPES][COEF_BANDS][PREV_COEF_CONTEXTS]
99
100
                                [ENTROPY_NODES];

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
124
125
126
127
// This is the index in the scan order beyond which all coefficients for
// 8x8 transform and above are in the top band.
// For 4x4 blocks the index is less but to keep things common the lookup
// table for 4x4 is padded out to this index.
#define MAXBAND_INDEX 21

Paul Wilkins's avatar
Paul Wilkins committed
128
129
130
131
extern const uint8_t vp9_coefband_trans_8x8plus[MAXBAND_INDEX + 1];
extern const uint8_t vp9_coefband_trans_4x4[MAXBAND_INDEX + 1];


Paul Wilkins's avatar
Paul Wilkins committed
132
133
134
static int get_coef_band(const uint8_t * band_translate, int coef_index) {
  return (coef_index > MAXBAND_INDEX)
    ? (COEF_BANDS-1) : band_translate[coef_index];
135
}
Paul Wilkins's avatar
Paul Wilkins committed
136

137
138
// 128 lists of probabilities are stored for the following ONE node probs:
// 1, 3, 5, 7, ..., 253, 255
139
140
// In between probabilities are interpolated linearly

141
#define COEFPROB_MODELS             128
142

143
#define UNCONSTRAINED_NODES         3
144

145
#define PIVOT_NODE                  2   // which node is pivot
146
147

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

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

155
void vp9_model_to_full_probs(const vp9_prob *model, vp9_prob *full);
156

157
158
static int get_entropy_context(TX_SIZE tx_size,
                               ENTROPY_CONTEXT *a, ENTROPY_CONTEXT *l) {
159
  ENTROPY_CONTEXT above_ec = 0, left_ec = 0;
160

161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
  switch (tx_size) {
    case TX_4X4:
      above_ec = a[0] != 0;
      left_ec = l[0] != 0;
      break;
    case TX_8X8:
      above_ec = !!*(uint16_t *)a;
      left_ec  = !!*(uint16_t *)l;
      break;
    case TX_16X16:
      above_ec = !!*(uint32_t *)a;
      left_ec  = !!*(uint32_t *)l;
      break;
    case TX_32X32:
      above_ec = !!*(uint64_t *)a;
      left_ec  = !!*(uint64_t *)l;
      break;
    default:
      assert(!"Invalid transform size.");
  }

  return combine_entropy_contexts(above_ec, left_ec);
}

static void get_scan_and_band(const MACROBLOCKD *xd, TX_SIZE tx_size,
                              PLANE_TYPE type, int block_idx,
                              const int16_t **scan,
188
                              const int16_t **scan_nb,
189
                              const uint8_t **band_translate) {
190
191
  switch (tx_size) {
    case TX_4X4:
192
      get_scan_nb_4x4(get_tx_type_4x4(type, xd, block_idx), scan, scan_nb);
193
194
195
      *band_translate = vp9_coefband_trans_4x4;
      break;
    case TX_8X8:
196
      get_scan_nb_8x8(get_tx_type_8x8(type, xd), scan, scan_nb);
197
198
199
      *band_translate = vp9_coefband_trans_8x8plus;
      break;
    case TX_16X16:
200
      get_scan_nb_16x16(get_tx_type_16x16(type, xd), scan, scan_nb);
201
202
203
204
      *band_translate = vp9_coefband_trans_8x8plus;
      break;
    case TX_32X32:
      *scan = vp9_default_scan_32x32;
205
      *scan_nb = vp9_default_scan_32x32_neighbors;
206
207
208
209
210
211
212
      *band_translate = vp9_coefband_trans_8x8plus;
      break;
    default:
      assert(!"Invalid transform size.");
  }
}

213
#endif  // VP9_COMMON_VP9_ENTROPY_H_