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 #ifndef VP9_COMMON_VP9_ENTROPY_H_
12 #define VP9_COMMON_VP9_ENTROPY_H_
13
14 #include "vpx/vpx_integer.h"
15
16 #include "vp9/common/vp9_blockd.h"
17 #include "vp9/common/vp9_common.h"
18 #include "vp9/common/vp9_scan.h"
19
20 #ifdef __cplusplus
21 extern "C" {
22 #endif
23
24 #define DIFF_UPDATE_PROB 252
25
26 // Coefficient token alphabet
27 #define ZERO_TOKEN 0 // 0 Extra Bits 0+0
28 #define ONE_TOKEN 1 // 1 Extra Bits 0+1
29 #define TWO_TOKEN 2 // 2 Extra Bits 0+1
30 #define THREE_TOKEN 3 // 3 Extra Bits 0+1
31 #define FOUR_TOKEN 4 // 4 Extra Bits 0+1
32 #define CATEGORY1_TOKEN 5 // 5-6 Extra Bits 1+1
33 #define CATEGORY2_TOKEN 6 // 7-10 Extra Bits 2+1
34 #define CATEGORY3_TOKEN 7 // 11-18 Extra Bits 3+1
35 #define CATEGORY4_TOKEN 8 // 19-34 Extra Bits 4+1
36 #define CATEGORY5_TOKEN 9 // 35-66 Extra Bits 5+1
37 #define CATEGORY6_TOKEN 10 // 67+ Extra Bits 14+1
38 #define EOB_TOKEN 11 // EOB Extra Bits 0+0
39
40 #define ENTROPY_TOKENS 12
41
42 #define ENTROPY_NODES 11
43
44 DECLARE_ALIGNED(16, extern const uint8_t, vp9_pt_energy_class[ENTROPY_TOKENS]);
45
46 #define EOB_MODEL_TOKEN 3
47 extern const vp9_tree_index vp9_coefmodel_tree[];
48
49 typedef struct {
50 const vp9_tree_index *tree;
51 const vp9_prob *prob;
52 int len;
53 int base_val;
54 } vp9_extra_bit;
55
56 // indexed by token value
57 extern const vp9_extra_bit vp9_extra_bits[ENTROPY_TOKENS];
58
59 #define DCT_MAX_VALUE 16384
60
61 /* Coefficients are predicted via a 3-dimensional probability table. */
62
63 #define REF_TYPES 2 // intra=0, inter=1
64
65 /* Middle dimension reflects the coefficient position within the transform. */
66 #define COEF_BANDS 6
67
68 /* Inside dimension is measure of nearby complexity, that reflects the energy
69 of nearby coefficients are nonzero. For the first coefficient (DC, unless
70 block type is 0), we look at the (already encoded) blocks above and to the
71 left of the current block. The context index is then the number (0,1,or 2)
72 of these blocks having nonzero coefficients.
73 After decoding a coefficient, the measure is determined by the size of the
74 most recently decoded coefficient.
75 Note that the intuitive meaning of this measure changes as coefficients
76 are decoded, e.g., prior to the first token, a zero means that my neighbors
77 are empty while, after the first token, because of the use of end-of-block,
78 a zero means we just decoded a zero and hence guarantees that a non-zero
79 coefficient will appear later in this block. However, this shift
80 in meaning is perfectly OK because our context depends also on the
81 coefficient band (and since zigzag positions 0, 1, and 2 are in
82 distinct bands). */
83
84 #define COEFF_CONTEXTS 6
85 #define BAND_COEFF_CONTEXTS(band) ((band) == 0 ? 3 : COEFF_CONTEXTS)
86
87 // #define ENTROPY_STATS
88
89 typedef unsigned int vp9_coeff_count[REF_TYPES][COEF_BANDS][COEFF_CONTEXTS]
90 [ENTROPY_TOKENS];
91 typedef unsigned int vp9_coeff_stats[REF_TYPES][COEF_BANDS][COEFF_CONTEXTS]
92 [ENTROPY_NODES][2];
93
94 #define SUBEXP_PARAM 4 /* Subexponential code parameter */
95 #define MODULUS_PARAM 13 /* Modulus parameter */
96
97 struct VP9Common;
98 void vp9_default_coef_probs(struct VP9Common *cm);
99 void vp9_adapt_coef_probs(struct VP9Common *cm);
100
reset_skip_context(MACROBLOCKD * xd,BLOCK_SIZE bsize)101 static INLINE void reset_skip_context(MACROBLOCKD *xd, BLOCK_SIZE bsize) {
102 int i;
103 for (i = 0; i < MAX_MB_PLANE; i++) {
104 struct macroblockd_plane *const pd = &xd->plane[i];
105 const BLOCK_SIZE plane_bsize = get_plane_block_size(bsize, pd);
106 vpx_memset(pd->above_context, 0, sizeof(ENTROPY_CONTEXT) *
107 num_4x4_blocks_wide_lookup[plane_bsize]);
108 vpx_memset(pd->left_context, 0, sizeof(ENTROPY_CONTEXT) *
109 num_4x4_blocks_high_lookup[plane_bsize]);
110 }
111 }
112
113 // This is the index in the scan order beyond which all coefficients for
114 // 8x8 transform and above are in the top band.
115 // This macro is currently unused but may be used by certain implementations
116 #define MAXBAND_INDEX 21
117
118 DECLARE_ALIGNED(16, extern const uint8_t, vp9_coefband_trans_8x8plus[1024]);
119 DECLARE_ALIGNED(16, extern const uint8_t, vp9_coefband_trans_4x4[16]);
120
get_band_translate(TX_SIZE tx_size)121 static INLINE const uint8_t *get_band_translate(TX_SIZE tx_size) {
122 return tx_size == TX_4X4 ? vp9_coefband_trans_4x4
123 : vp9_coefband_trans_8x8plus;
124 }
125
126 // 128 lists of probabilities are stored for the following ONE node probs:
127 // 1, 3, 5, 7, ..., 253, 255
128 // In between probabilities are interpolated linearly
129
130 #define COEFF_PROB_MODELS 256
131
132 #define UNCONSTRAINED_NODES 3
133
134 #define PIVOT_NODE 2 // which node is pivot
135
136 #define MODEL_NODES (ENTROPY_NODES - UNCONSTRAINED_NODES)
137 extern const vp9_prob vp9_pareto8_full[COEFF_PROB_MODELS][MODEL_NODES];
138
139 typedef vp9_prob vp9_coeff_probs_model[REF_TYPES][COEF_BANDS]
140 [COEFF_CONTEXTS][UNCONSTRAINED_NODES];
141
142 typedef unsigned int vp9_coeff_count_model[REF_TYPES][COEF_BANDS]
143 [COEFF_CONTEXTS]
144 [UNCONSTRAINED_NODES + 1];
145
146 void vp9_model_to_full_probs(const vp9_prob *model, vp9_prob *full);
147
get_entropy_context(TX_SIZE tx_size,const ENTROPY_CONTEXT * a,const ENTROPY_CONTEXT * l)148 static INLINE int get_entropy_context(TX_SIZE tx_size, const ENTROPY_CONTEXT *a,
149 const ENTROPY_CONTEXT *l) {
150 ENTROPY_CONTEXT above_ec = 0, left_ec = 0;
151
152 switch (tx_size) {
153 case TX_4X4:
154 above_ec = a[0] != 0;
155 left_ec = l[0] != 0;
156 break;
157 case TX_8X8:
158 above_ec = !!*(const uint16_t *)a;
159 left_ec = !!*(const uint16_t *)l;
160 break;
161 case TX_16X16:
162 above_ec = !!*(const uint32_t *)a;
163 left_ec = !!*(const uint32_t *)l;
164 break;
165 case TX_32X32:
166 above_ec = !!*(const uint64_t *)a;
167 left_ec = !!*(const uint64_t *)l;
168 break;
169 default:
170 assert(0 && "Invalid transform size.");
171 }
172
173 return combine_entropy_contexts(above_ec, left_ec);
174 }
175
get_scan(const MACROBLOCKD * xd,TX_SIZE tx_size,PLANE_TYPE type,int block_idx)176 INLINE static const scan_order *get_scan(const MACROBLOCKD *xd, TX_SIZE tx_size,
177 PLANE_TYPE type, int block_idx) {
178 const MODE_INFO *const mi = xd->mi[0];
179
180 if (is_inter_block(&mi->mbmi) || type != PLANE_TYPE_Y || xd->lossless) {
181 return &vp9_default_scan_orders[tx_size];
182 } else {
183 const MB_PREDICTION_MODE mode = get_y_mode(mi, block_idx);
184 return &vp9_scan_orders[tx_size][intra_mode_to_tx_type_lookup[mode]];
185 }
186 }
187
188 #ifdef __cplusplus
189 } // extern "C"
190 #endif
191
192 #endif // VP9_COMMON_VP9_ENTROPY_H_
193