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
12 #include "boolhuff.h"
13 #include "blockd.h"
14
15
16
17 #if defined(SECTIONBITS_OUTPUT)
18 unsigned __int64 Sectionbits[500];
19
20 #endif
21
22 #ifdef ENTROPY_STATS
23 unsigned int active_section = 0;
24 #endif
25
26 const unsigned int vp8_prob_cost[256] =
27 {
28 2047, 2047, 1791, 1641, 1535, 1452, 1385, 1328, 1279, 1235, 1196, 1161, 1129, 1099, 1072, 1046,
29 1023, 1000, 979, 959, 940, 922, 905, 889, 873, 858, 843, 829, 816, 803, 790, 778,
30 767, 755, 744, 733, 723, 713, 703, 693, 684, 675, 666, 657, 649, 641, 633, 625,
31 617, 609, 602, 594, 587, 580, 573, 567, 560, 553, 547, 541, 534, 528, 522, 516,
32 511, 505, 499, 494, 488, 483, 477, 472, 467, 462, 457, 452, 447, 442, 437, 433,
33 428, 424, 419, 415, 410, 406, 401, 397, 393, 389, 385, 381, 377, 373, 369, 365,
34 361, 357, 353, 349, 346, 342, 338, 335, 331, 328, 324, 321, 317, 314, 311, 307,
35 304, 301, 297, 294, 291, 288, 285, 281, 278, 275, 272, 269, 266, 263, 260, 257,
36 255, 252, 249, 246, 243, 240, 238, 235, 232, 229, 227, 224, 221, 219, 216, 214,
37 211, 208, 206, 203, 201, 198, 196, 194, 191, 189, 186, 184, 181, 179, 177, 174,
38 172, 170, 168, 165, 163, 161, 159, 156, 154, 152, 150, 148, 145, 143, 141, 139,
39 137, 135, 133, 131, 129, 127, 125, 123, 121, 119, 117, 115, 113, 111, 109, 107,
40 105, 103, 101, 99, 97, 95, 93, 92, 90, 88, 86, 84, 82, 81, 79, 77,
41 75, 73, 72, 70, 68, 66, 65, 63, 61, 60, 58, 56, 55, 53, 51, 50,
42 48, 46, 45, 43, 41, 40, 38, 37, 35, 33, 32, 30, 29, 27, 25, 24,
43 22, 21, 19, 18, 16, 15, 13, 12, 10, 9, 7, 6, 4, 3, 1, 1
44 };
45
vp8_start_encode(BOOL_CODER * br,unsigned char * source)46 void vp8_start_encode(BOOL_CODER *br, unsigned char *source)
47 {
48
49 br->lowvalue = 0;
50 br->range = 255;
51 br->value = 0;
52 br->count = -24;
53 br->buffer = source;
54 br->pos = 0;
55 }
56
vp8_stop_encode(BOOL_CODER * br)57 void vp8_stop_encode(BOOL_CODER *br)
58 {
59 int i;
60
61 for (i = 0; i < 32; i++)
62 vp8_encode_bool(br, 0, 128);
63 }
64
65 DECLARE_ALIGNED(16, static const unsigned int, norm[256]) =
66 {
67 0, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
68 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
69 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
70 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
71 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
72 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
73 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
74 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
75 };
76
vp8_encode_bool(BOOL_CODER * br,int bit,int probability)77 void vp8_encode_bool(BOOL_CODER *br, int bit, int probability)
78 {
79 unsigned int split;
80 int count = br->count;
81 unsigned int range = br->range;
82 unsigned int lowvalue = br->lowvalue;
83 register unsigned int shift;
84
85 #ifdef ENTROPY_STATS
86 #if defined(SECTIONBITS_OUTPUT)
87
88 if (bit)
89 Sectionbits[active_section] += vp8_prob_cost[255-probability];
90 else
91 Sectionbits[active_section] += vp8_prob_cost[probability];
92
93 #endif
94 #endif
95
96 split = 1 + (((range - 1) * probability) >> 8);
97
98 range = split;
99
100 if (bit)
101 {
102 lowvalue += split;
103 range = br->range - split;
104 }
105
106 shift = norm[range];
107
108 range <<= shift;
109 count += shift;
110
111 if (count >= 0)
112 {
113 int offset = shift - count;
114
115 if ((lowvalue << (offset - 1)) & 0x80000000)
116 {
117 int x = br->pos - 1;
118
119 while (x >= 0 && br->buffer[x] == 0xff)
120 {
121 br->buffer[x] = (unsigned char)0;
122 x--;
123 }
124
125 br->buffer[x] += 1;
126 }
127
128 br->buffer[br->pos++] = (lowvalue >> (24 - offset));
129 lowvalue <<= offset;
130 shift = count;
131 lowvalue &= 0xffffff;
132 count -= 8 ;
133 }
134
135 lowvalue <<= shift;
136 br->count = count;
137 br->lowvalue = lowvalue;
138 br->range = range;
139 }
140
vp8_encode_value(BOOL_CODER * br,int data,int bits)141 void vp8_encode_value(BOOL_CODER *br, int data, int bits)
142 {
143 int bit;
144
145 for (bit = bits - 1; bit >= 0; bit--)
146 vp8_encode_bool(br, (1 & (data >> bit)), 0x80);
147
148 }
149