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 #include "vpx_dsp/prob.h"
16 
17 #include "vp9/common/vp9_common.h"
18 #include "vp9/common/vp9_enums.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 CAT1_MIN_VAL    5
47 #define CAT2_MIN_VAL    7
48 #define CAT3_MIN_VAL   11
49 #define CAT4_MIN_VAL   19
50 #define CAT5_MIN_VAL   35
51 #define CAT6_MIN_VAL   67
52 
53 // Extra bit probabilities.
54 DECLARE_ALIGNED(16, extern const uint8_t, vp9_cat1_prob[1]);
55 DECLARE_ALIGNED(16, extern const uint8_t, vp9_cat2_prob[2]);
56 DECLARE_ALIGNED(16, extern const uint8_t, vp9_cat3_prob[3]);
57 DECLARE_ALIGNED(16, extern const uint8_t, vp9_cat4_prob[4]);
58 DECLARE_ALIGNED(16, extern const uint8_t, vp9_cat5_prob[5]);
59 DECLARE_ALIGNED(16, extern const uint8_t, vp9_cat6_prob[14]);
60 
61 #if CONFIG_VP9_HIGHBITDEPTH
62 DECLARE_ALIGNED(16, extern const uint8_t, vp9_cat1_prob_high10[1]);
63 DECLARE_ALIGNED(16, extern const uint8_t, vp9_cat2_prob_high10[2]);
64 DECLARE_ALIGNED(16, extern const uint8_t, vp9_cat3_prob_high10[3]);
65 DECLARE_ALIGNED(16, extern const uint8_t, vp9_cat4_prob_high10[4]);
66 DECLARE_ALIGNED(16, extern const uint8_t, vp9_cat5_prob_high10[5]);
67 DECLARE_ALIGNED(16, extern const uint8_t, vp9_cat6_prob_high10[16]);
68 DECLARE_ALIGNED(16, extern const uint8_t, vp9_cat1_prob_high12[1]);
69 DECLARE_ALIGNED(16, extern const uint8_t, vp9_cat2_prob_high12[2]);
70 DECLARE_ALIGNED(16, extern const uint8_t, vp9_cat3_prob_high12[3]);
71 DECLARE_ALIGNED(16, extern const uint8_t, vp9_cat4_prob_high12[4]);
72 DECLARE_ALIGNED(16, extern const uint8_t, vp9_cat5_prob_high12[5]);
73 DECLARE_ALIGNED(16, extern const uint8_t, vp9_cat6_prob_high12[18]);
74 #endif  // CONFIG_VP9_HIGHBITDEPTH
75 
76 #define EOB_MODEL_TOKEN 3
77 
78 #define DCT_MAX_VALUE           16384
79 #if CONFIG_VP9_HIGHBITDEPTH
80 #define DCT_MAX_VALUE_HIGH10    65536
81 #define DCT_MAX_VALUE_HIGH12   262144
82 #endif  // CONFIG_VP9_HIGHBITDEPTH
83 
84 /* Coefficients are predicted via a 3-dimensional probability table. */
85 
86 #define REF_TYPES 2  // intra=0, inter=1
87 
88 /* Middle dimension reflects the coefficient position within the transform. */
89 #define COEF_BANDS 6
90 
91 /* Inside dimension is measure of nearby complexity, that reflects the energy
92    of nearby coefficients are nonzero.  For the first coefficient (DC, unless
93    block type is 0), we look at the (already encoded) blocks above and to the
94    left of the current block.  The context index is then the number (0,1,or 2)
95    of these blocks having nonzero coefficients.
96    After decoding a coefficient, the measure is determined by the size of the
97    most recently decoded coefficient.
98    Note that the intuitive meaning of this measure changes as coefficients
99    are decoded, e.g., prior to the first token, a zero means that my neighbors
100    are empty while, after the first token, because of the use of end-of-block,
101    a zero means we just decoded a zero and hence guarantees that a non-zero
102    coefficient will appear later in this block.  However, this shift
103    in meaning is perfectly OK because our context depends also on the
104    coefficient band (and since zigzag positions 0, 1, and 2 are in
105    distinct bands). */
106 
107 #define COEFF_CONTEXTS 6
108 #define BAND_COEFF_CONTEXTS(band) ((band) == 0 ? 3 : COEFF_CONTEXTS)
109 
110 // #define ENTROPY_STATS
111 
112 typedef unsigned int vp9_coeff_count[REF_TYPES][COEF_BANDS][COEFF_CONTEXTS]
113                                     [ENTROPY_TOKENS];
114 typedef unsigned int vp9_coeff_stats[REF_TYPES][COEF_BANDS][COEFF_CONTEXTS]
115                                     [ENTROPY_NODES][2];
116 
117 #define SUBEXP_PARAM                4   /* Subexponential code parameter */
118 #define MODULUS_PARAM               13  /* Modulus parameter */
119 
120 struct VP9Common;
121 void vp9_default_coef_probs(struct VP9Common *cm);
122 void vp9_adapt_coef_probs(struct VP9Common *cm);
123 
124 // This is the index in the scan order beyond which all coefficients for
125 // 8x8 transform and above are in the top band.
126 // This macro is currently unused but may be used by certain implementations
127 #define MAXBAND_INDEX 21
128 
129 DECLARE_ALIGNED(16, extern const uint8_t, vp9_coefband_trans_8x8plus[1024]);
130 DECLARE_ALIGNED(16, extern const uint8_t, vp9_coefband_trans_4x4[16]);
131 
get_band_translate(TX_SIZE tx_size)132 static INLINE const uint8_t *get_band_translate(TX_SIZE tx_size) {
133   return tx_size == TX_4X4 ? vp9_coefband_trans_4x4
134                            : vp9_coefband_trans_8x8plus;
135 }
136 
137 // 128 lists of probabilities are stored for the following ONE node probs:
138 // 1, 3, 5, 7, ..., 253, 255
139 // In between probabilities are interpolated linearly
140 
141 #define COEFF_PROB_MODELS 256
142 
143 #define UNCONSTRAINED_NODES         3
144 
145 #define PIVOT_NODE                  2   // which node is pivot
146 
147 #define MODEL_NODES (ENTROPY_NODES - UNCONSTRAINED_NODES)
148 extern const vpx_tree_index vp9_coef_con_tree[TREE_SIZE(ENTROPY_TOKENS)];
149 extern const vpx_prob vp9_pareto8_full[COEFF_PROB_MODELS][MODEL_NODES];
150 
151 typedef vpx_prob vp9_coeff_probs_model[REF_TYPES][COEF_BANDS]
152                                       [COEFF_CONTEXTS][UNCONSTRAINED_NODES];
153 
154 typedef unsigned int vp9_coeff_count_model[REF_TYPES][COEF_BANDS]
155                                           [COEFF_CONTEXTS]
156                                           [UNCONSTRAINED_NODES + 1];
157 
158 void vp9_model_to_full_probs(const vpx_prob *model, vpx_prob *full);
159 
160 typedef char ENTROPY_CONTEXT;
161 
combine_entropy_contexts(ENTROPY_CONTEXT a,ENTROPY_CONTEXT b)162 static INLINE int combine_entropy_contexts(ENTROPY_CONTEXT a,
163                                            ENTROPY_CONTEXT b) {
164   return (a != 0) + (b != 0);
165 }
166 
get_entropy_context(TX_SIZE tx_size,const ENTROPY_CONTEXT * a,const ENTROPY_CONTEXT * l)167 static INLINE int get_entropy_context(TX_SIZE tx_size, const ENTROPY_CONTEXT *a,
168                                       const ENTROPY_CONTEXT *l) {
169   ENTROPY_CONTEXT above_ec = 0, left_ec = 0;
170 
171   switch (tx_size) {
172     case TX_4X4:
173       above_ec = a[0] != 0;
174       left_ec = l[0] != 0;
175       break;
176     case TX_8X8:
177       above_ec = !!*(const uint16_t *)a;
178       left_ec  = !!*(const uint16_t *)l;
179       break;
180     case TX_16X16:
181       above_ec = !!*(const uint32_t *)a;
182       left_ec  = !!*(const uint32_t *)l;
183       break;
184     case TX_32X32:
185       above_ec = !!*(const uint64_t *)a;
186       left_ec  = !!*(const uint64_t *)l;
187       break;
188     default:
189       assert(0 && "Invalid transform size.");
190       break;
191   }
192 
193   return combine_entropy_contexts(above_ec, left_ec);
194 }
195 
196 #ifdef __cplusplus
197 }  // extern "C"
198 #endif
199 
200 #endif  // VP9_COMMON_VP9_ENTROPY_H_
201