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vp8/pred.go (6K)
1 // Copyright 2011 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
4
5 package vp8
6
7 // This file implements parsing the predictor modes, as specified in chapter
8 // 11.
9
10 func (d *Decoder) parsePredModeY16(mbx int) {
11 var p uint8
12 if !d.fp.readBit(156) {
13 if !d.fp.readBit(163) {
14 p = predDC
15 } else {
16 p = predVE
17 }
18 } else if !d.fp.readBit(128) {
19 p = predHE
20 } else {
21 p = predTM
22 }
23 for i := 0; i < 4; i++ {
24 d.upMB[mbx].pred[i] = p
25 d.leftMB.pred[i] = p
26 }
27 d.predY16 = p
28 }
29
30 func (d *Decoder) parsePredModeC8() {
31 if !d.fp.readBit(142) {
32 d.predC8 = predDC
33 } else if !d.fp.readBit(114) {
34 d.predC8 = predVE
35 } else if !d.fp.readBit(183) {
36 d.predC8 = predHE
37 } else {
38 d.predC8 = predTM
39 }
40 }
41
42 func (d *Decoder) parsePredModeY4(mbx int) {
43 for j := 0; j < 4; j++ {
44 p := d.leftMB.pred[j]
45 for i := 0; i < 4; i++ {
46 prob := &predProb[d.upMB[mbx].pred[i]][p]
47 if !d.fp.readBit(prob[0]) {
48 p = predDC
49 } else if !d.fp.readBit(prob[1]) {
50 p = predTM
51 } else if !d.fp.readBit(prob[2]) {
52 p = predVE
53 } else if !d.fp.readBit(prob[3]) {
54 if !d.fp.readBit(prob[4]) {
55 p = predHE
56 } else if !d.fp.readBit(prob[5]) {
57 p = predRD
58 } else {
59 p = predVR
60 }
61 } else if !d.fp.readBit(prob[6]) {
62 p = predLD
63 } else if !d.fp.readBit(prob[7]) {
64 p = predVL
65 } else if !d.fp.readBit(prob[8]) {
66 p = predHD
67 } else {
68 p = predHU
69 }
70 d.predY4[j][i] = p
71 d.upMB[mbx].pred[i] = p
72 }
73 d.leftMB.pred[j] = p
74 }
75 }
76
77 // predProb are the probabilities to decode a 4x4 region's predictor mode given
78 // the predictor modes of the regions above and left of it.
79 // These values are specified in section 11.5.
80 var predProb = [nPred][nPred][9]uint8{
81 {
82 {231, 120, 48, 89, 115, 113, 120, 152, 112},
83 {152, 179, 64, 126, 170, 118, 46, 70, 95},
84 {175, 69, 143, 80, 85, 82, 72, 155, 103},
85 {56, 58, 10, 171, 218, 189, 17, 13, 152},
86 {114, 26, 17, 163, 44, 195, 21, 10, 173},
87 {121, 24, 80, 195, 26, 62, 44, 64, 85},
88 {144, 71, 10, 38, 171, 213, 144, 34, 26},
89 {170, 46, 55, 19, 136, 160, 33, 206, 71},
90 {63, 20, 8, 114, 114, 208, 12, 9, 226},
91 {81, 40, 11, 96, 182, 84, 29, 16, 36},
92 },
93 {
94 {134, 183, 89, 137, 98, 101, 106, 165, 148},
95 {72, 187, 100, 130, 157, 111, 32, 75, 80},
96 {66, 102, 167, 99, 74, 62, 40, 234, 128},
97 {41, 53, 9, 178, 241, 141, 26, 8, 107},
98 {74, 43, 26, 146, 73, 166, 49, 23, 157},
99 {65, 38, 105, 160, 51, 52, 31, 115, 128},
100 {104, 79, 12, 27, 217, 255, 87, 17, 7},
101 {87, 68, 71, 44, 114, 51, 15, 186, 23},
102 {47, 41, 14, 110, 182, 183, 21, 17, 194},
103 {66, 45, 25, 102, 197, 189, 23, 18, 22},
104 },
105 {
106 {88, 88, 147, 150, 42, 46, 45, 196, 205},
107 {43, 97, 183, 117, 85, 38, 35, 179, 61},
108 {39, 53, 200, 87, 26, 21, 43, 232, 171},
109 {56, 34, 51, 104, 114, 102, 29, 93, 77},
110 {39, 28, 85, 171, 58, 165, 90, 98, 64},
111 {34, 22, 116, 206, 23, 34, 43, 166, 73},
112 {107, 54, 32, 26, 51, 1, 81, 43, 31},
113 {68, 25, 106, 22, 64, 171, 36, 225, 114},
114 {34, 19, 21, 102, 132, 188, 16, 76, 124},
115 {62, 18, 78, 95, 85, 57, 50, 48, 51},
116 },
117 {
118 {193, 101, 35, 159, 215, 111, 89, 46, 111},
119 {60, 148, 31, 172, 219, 228, 21, 18, 111},
120 {112, 113, 77, 85, 179, 255, 38, 120, 114},
121 {40, 42, 1, 196, 245, 209, 10, 25, 109},
122 {88, 43, 29, 140, 166, 213, 37, 43, 154},
123 {61, 63, 30, 155, 67, 45, 68, 1, 209},
124 {100, 80, 8, 43, 154, 1, 51, 26, 71},
125 {142, 78, 78, 16, 255, 128, 34, 197, 171},
126 {41, 40, 5, 102, 211, 183, 4, 1, 221},
127 {51, 50, 17, 168, 209, 192, 23, 25, 82},
128 },
129 {
130 {138, 31, 36, 171, 27, 166, 38, 44, 229},
131 {67, 87, 58, 169, 82, 115, 26, 59, 179},
132 {63, 59, 90, 180, 59, 166, 93, 73, 154},
133 {40, 40, 21, 116, 143, 209, 34, 39, 175},
134 {47, 15, 16, 183, 34, 223, 49, 45, 183},
135 {46, 17, 33, 183, 6, 98, 15, 32, 183},
136 {57, 46, 22, 24, 128, 1, 54, 17, 37},
137 {65, 32, 73, 115, 28, 128, 23, 128, 205},
138 {40, 3, 9, 115, 51, 192, 18, 6, 223},
139 {87, 37, 9, 115, 59, 77, 64, 21, 47},
140 },
141 {
142 {104, 55, 44, 218, 9, 54, 53, 130, 226},
143 {64, 90, 70, 205, 40, 41, 23, 26, 57},
144 {54, 57, 112, 184, 5, 41, 38, 166, 213},
145 {30, 34, 26, 133, 152, 116, 10, 32, 134},
146 {39, 19, 53, 221, 26, 114, 32, 73, 255},
147 {31, 9, 65, 234, 2, 15, 1, 118, 73},
148 {75, 32, 12, 51, 192, 255, 160, 43, 51},
149 {88, 31, 35, 67, 102, 85, 55, 186, 85},
150 {56, 21, 23, 111, 59, 205, 45, 37, 192},
151 {55, 38, 70, 124, 73, 102, 1, 34, 98},
152 },
153 {
154 {125, 98, 42, 88, 104, 85, 117, 175, 82},
155 {95, 84, 53, 89, 128, 100, 113, 101, 45},
156 {75, 79, 123, 47, 51, 128, 81, 171, 1},
157 {57, 17, 5, 71, 102, 57, 53, 41, 49},
158 {38, 33, 13, 121, 57, 73, 26, 1, 85},
159 {41, 10, 67, 138, 77, 110, 90, 47, 114},
160 {115, 21, 2, 10, 102, 255, 166, 23, 6},
161 {101, 29, 16, 10, 85, 128, 101, 196, 26},
162 {57, 18, 10, 102, 102, 213, 34, 20, 43},
163 {117, 20, 15, 36, 163, 128, 68, 1, 26},
164 },
165 {
166 {102, 61, 71, 37, 34, 53, 31, 243, 192},
167 {69, 60, 71, 38, 73, 119, 28, 222, 37},
168 {68, 45, 128, 34, 1, 47, 11, 245, 171},
169 {62, 17, 19, 70, 146, 85, 55, 62, 70},
170 {37, 43, 37, 154, 100, 163, 85, 160, 1},
171 {63, 9, 92, 136, 28, 64, 32, 201, 85},
172 {75, 15, 9, 9, 64, 255, 184, 119, 16},
173 {86, 6, 28, 5, 64, 255, 25, 248, 1},
174 {56, 8, 17, 132, 137, 255, 55, 116, 128},
175 {58, 15, 20, 82, 135, 57, 26, 121, 40},
176 },
177 {
178 {164, 50, 31, 137, 154, 133, 25, 35, 218},
179 {51, 103, 44, 131, 131, 123, 31, 6, 158},
180 {86, 40, 64, 135, 148, 224, 45, 183, 128},
181 {22, 26, 17, 131, 240, 154, 14, 1, 209},
182 {45, 16, 21, 91, 64, 222, 7, 1, 197},
183 {56, 21, 39, 155, 60, 138, 23, 102, 213},
184 {83, 12, 13, 54, 192, 255, 68, 47, 28},
185 {85, 26, 85, 85, 128, 128, 32, 146, 171},
186 {18, 11, 7, 63, 144, 171, 4, 4, 246},
187 {35, 27, 10, 146, 174, 171, 12, 26, 128},
188 },
189 {
190 {190, 80, 35, 99, 180, 80, 126, 54, 45},
191 {85, 126, 47, 87, 176, 51, 41, 20, 32},
192 {101, 75, 128, 139, 118, 146, 116, 128, 85},
193 {56, 41, 15, 176, 236, 85, 37, 9, 62},
194 {71, 30, 17, 119, 118, 255, 17, 18, 138},
195 {101, 38, 60, 138, 55, 70, 43, 26, 142},
196 {146, 36, 19, 30, 171, 255, 97, 27, 20},
197 {138, 45, 61, 62, 219, 1, 81, 188, 64},
198 {32, 41, 20, 117, 151, 142, 20, 21, 163},
199 {112, 19, 12, 61, 195, 128, 48, 4, 24},
200 },
201 }