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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 typedef struct {
79   const vpx_tree_index *tree;
80   const vpx_prob *prob;
81   int len;
82   int base_val;
83   const int16_t *cost;
84 } vp9_extra_bit;
85 
86 // indexed by token value
87 extern const vp9_extra_bit vp9_extra_bits[ENTROPY_TOKENS];
88 #if CONFIG_VP9_HIGHBITDEPTH
89 extern const vp9_extra_bit vp9_extra_bits_high10[ENTROPY_TOKENS];
90 extern const vp9_extra_bit vp9_extra_bits_high12[ENTROPY_TOKENS];
91 #endif  // CONFIG_VP9_HIGHBITDEPTH
92 
93 #define DCT_MAX_VALUE           16384
94 #if CONFIG_VP9_HIGHBITDEPTH
95 #define DCT_MAX_VALUE_HIGH10    65536
96 #define DCT_MAX_VALUE_HIGH12   262144
97 #endif  // CONFIG_VP9_HIGHBITDEPTH
98 
99 /* Coefficients are predicted via a 3-dimensional probability table. */
100 
101 #define REF_TYPES 2  // intra=0, inter=1
102 
103 /* Middle dimension reflects the coefficient position within the transform. */
104 #define COEF_BANDS 6
105 
106 /* Inside dimension is measure of nearby complexity, that reflects the energy
107    of nearby coefficients are nonzero.  For the first coefficient (DC, unless
108    block type is 0), we look at the (already encoded) blocks above and to the
109    left of the current block.  The context index is then the number (0,1,or 2)
110    of these blocks having nonzero coefficients.
111    After decoding a coefficient, the measure is determined by the size of the
112    most recently decoded coefficient.
113    Note that the intuitive meaning of this measure changes as coefficients
114    are decoded, e.g., prior to the first token, a zero means that my neighbors
115    are empty while, after the first token, because of the use of end-of-block,
116    a zero means we just decoded a zero and hence guarantees that a non-zero
117    coefficient will appear later in this block.  However, this shift
118    in meaning is perfectly OK because our context depends also on the
119    coefficient band (and since zigzag positions 0, 1, and 2 are in
120    distinct bands). */
121 
122 #define COEFF_CONTEXTS 6
123 #define BAND_COEFF_CONTEXTS(band) ((band) == 0 ? 3 : COEFF_CONTEXTS)
124 
125 // #define ENTROPY_STATS
126 
127 typedef unsigned int vp9_coeff_count[REF_TYPES][COEF_BANDS][COEFF_CONTEXTS]
128                                     [ENTROPY_TOKENS];
129 typedef unsigned int vp9_coeff_stats[REF_TYPES][COEF_BANDS][COEFF_CONTEXTS]
130                                     [ENTROPY_NODES][2];
131 
132 #define SUBEXP_PARAM                4   /* Subexponential code parameter */
133 #define MODULUS_PARAM               13  /* Modulus parameter */
134 
135 struct VP9Common;
136 void vp9_default_coef_probs(struct VP9Common *cm);
137 void vp9_adapt_coef_probs(struct VP9Common *cm);
138 
139 // This is the index in the scan order beyond which all coefficients for
140 // 8x8 transform and above are in the top band.
141 // This macro is currently unused but may be used by certain implementations
142 #define MAXBAND_INDEX 21
143 
144 DECLARE_ALIGNED(16, extern const uint8_t, vp9_coefband_trans_8x8plus[1024]);
145 DECLARE_ALIGNED(16, extern const uint8_t, vp9_coefband_trans_4x4[16]);
146 
get_band_translate(TX_SIZE tx_size)147 static INLINE const uint8_t *get_band_translate(TX_SIZE tx_size) {
148   return tx_size == TX_4X4 ? vp9_coefband_trans_4x4
149                            : vp9_coefband_trans_8x8plus;
150 }
151 
152 // 128 lists of probabilities are stored for the following ONE node probs:
153 // 1, 3, 5, 7, ..., 253, 255
154 // In between probabilities are interpolated linearly
155 
156 #define COEFF_PROB_MODELS 256
157 
158 #define UNCONSTRAINED_NODES         3
159 
160 #define PIVOT_NODE                  2   // which node is pivot
161 
162 #define MODEL_NODES (ENTROPY_NODES - UNCONSTRAINED_NODES)
163 extern const vpx_tree_index vp9_coef_con_tree[TREE_SIZE(ENTROPY_TOKENS)];
164 extern const vpx_prob vp9_pareto8_full[COEFF_PROB_MODELS][MODEL_NODES];
165 
166 typedef vpx_prob vp9_coeff_probs_model[REF_TYPES][COEF_BANDS]
167                                       [COEFF_CONTEXTS][UNCONSTRAINED_NODES];
168 
169 typedef unsigned int vp9_coeff_count_model[REF_TYPES][COEF_BANDS]
170                                           [COEFF_CONTEXTS]
171                                           [UNCONSTRAINED_NODES + 1];
172 
173 void vp9_model_to_full_probs(const vpx_prob *model, vpx_prob *full);
174 
175 typedef char ENTROPY_CONTEXT;
176 
combine_entropy_contexts(ENTROPY_CONTEXT a,ENTROPY_CONTEXT b)177 static INLINE int combine_entropy_contexts(ENTROPY_CONTEXT a,
178                                            ENTROPY_CONTEXT b) {
179   return (a != 0) + (b != 0);
180 }
181 
get_entropy_context(TX_SIZE tx_size,const ENTROPY_CONTEXT * a,const ENTROPY_CONTEXT * l)182 static INLINE int get_entropy_context(TX_SIZE tx_size, const ENTROPY_CONTEXT *a,
183                                       const ENTROPY_CONTEXT *l) {
184   ENTROPY_CONTEXT above_ec = 0, left_ec = 0;
185 
186   switch (tx_size) {
187     case TX_4X4:
188       above_ec = a[0] != 0;
189       left_ec = l[0] != 0;
190       break;
191     case TX_8X8:
192       above_ec = !!*(const uint16_t *)a;
193       left_ec  = !!*(const uint16_t *)l;
194       break;
195     case TX_16X16:
196       above_ec = !!*(const uint32_t *)a;
197       left_ec  = !!*(const uint32_t *)l;
198       break;
199     case TX_32X32:
200       above_ec = !!*(const uint64_t *)a;
201       left_ec  = !!*(const uint64_t *)l;
202       break;
203     default:
204       assert(0 && "Invalid transform size.");
205       break;
206   }
207 
208   return combine_entropy_contexts(above_ec, left_ec);
209 }
210 
211 #ifdef __cplusplus
212 }  // extern "C"
213 #endif
214 
215 #endif  // VP9_COMMON_VP9_ENTROPY_H_
216