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 VPX_VP9_COMMON_VP9_ENTROPY_H_
12 #define VPX_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 #define COEFF_PROB_MODELS 255
141 
142 #define UNCONSTRAINED_NODES 3
143 
144 #define PIVOT_NODE 2  // which node is pivot
145 
146 #define MODEL_NODES (ENTROPY_NODES - UNCONSTRAINED_NODES)
147 extern const vpx_tree_index vp9_coef_con_tree[TREE_SIZE(ENTROPY_TOKENS)];
148 extern const vpx_prob vp9_pareto8_full[COEFF_PROB_MODELS][MODEL_NODES];
149 
150 typedef vpx_prob vp9_coeff_probs_model[REF_TYPES][COEF_BANDS][COEFF_CONTEXTS]
151                                       [UNCONSTRAINED_NODES];
152 
153 typedef unsigned int vp9_coeff_count_model[REF_TYPES][COEF_BANDS]
154                                           [COEFF_CONTEXTS]
155                                           [UNCONSTRAINED_NODES + 1];
156 
157 void vp9_model_to_full_probs(const vpx_prob *model, vpx_prob *full);
158 
159 typedef char ENTROPY_CONTEXT;
160 
combine_entropy_contexts(ENTROPY_CONTEXT a,ENTROPY_CONTEXT b)161 static INLINE int combine_entropy_contexts(ENTROPY_CONTEXT a,
162                                            ENTROPY_CONTEXT b) {
163   return (a != 0) + (b != 0);
164 }
165 
get_entropy_context(TX_SIZE tx_size,const ENTROPY_CONTEXT * a,const ENTROPY_CONTEXT * l)166 static INLINE int get_entropy_context(TX_SIZE tx_size, const ENTROPY_CONTEXT *a,
167                                       const ENTROPY_CONTEXT *l) {
168   ENTROPY_CONTEXT above_ec = 0, left_ec = 0;
169 
170   switch (tx_size) {
171     case TX_4X4:
172       above_ec = a[0] != 0;
173       left_ec = l[0] != 0;
174       break;
175     case TX_8X8:
176       above_ec = !!*(const uint16_t *)a;
177       left_ec = !!*(const uint16_t *)l;
178       break;
179     case TX_16X16:
180       above_ec = !!*(const uint32_t *)a;
181       left_ec = !!*(const uint32_t *)l;
182       break;
183     case TX_32X32:
184       above_ec = !!*(const uint64_t *)a;
185       left_ec = !!*(const uint64_t *)l;
186       break;
187     default: assert(0 && "Invalid transform size."); break;
188   }
189 
190   return combine_entropy_contexts(above_ec, left_ec);
191 }
192 
193 #ifdef __cplusplus
194 }  // extern "C"
195 #endif
196 
197 #endif  // VPX_VP9_COMMON_VP9_ENTROPY_H_
198