1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
|
/*
* Copyright (c) 2016, Alliance for Open Media. All rights reserved
*
* This source code is subject to the terms of the BSD 2 Clause License and
* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
* was not distributed with this source code in the LICENSE file, you can
* obtain it at www.aomedia.org/license/software. If the Alliance for Open
* Media Patent License 1.0 was not distributed with this source code in the
* PATENTS file, you can obtain it at www.aomedia.org/license/patent.
*/
#include <assert.h>
#include <limits.h>
#include <stdlib.h>
#include "config/aom_config.h"
#include "aom_dsp/bitwriter_buffer.h"
#include "aom_dsp/recenter.h"
#include "aom_ports/bitops.h"
int aom_wb_is_byte_aligned(const struct aom_write_bit_buffer *wb) {
return (wb->bit_offset % CHAR_BIT == 0);
}
uint32_t aom_wb_bytes_written(const struct aom_write_bit_buffer *wb) {
return wb->bit_offset / CHAR_BIT + (wb->bit_offset % CHAR_BIT > 0);
}
void aom_wb_write_bit(struct aom_write_bit_buffer *wb, int bit) {
const int off = (int)wb->bit_offset;
const int p = off / CHAR_BIT;
const int q = CHAR_BIT - 1 - off % CHAR_BIT;
if (q == CHAR_BIT - 1) {
// Zero next char and write bit
wb->bit_buffer[p] = bit << q;
} else {
wb->bit_buffer[p] &= ~(1 << q);
wb->bit_buffer[p] |= bit << q;
}
wb->bit_offset = off + 1;
}
void aom_wb_overwrite_bit(struct aom_write_bit_buffer *wb, int bit) {
// Do not zero bytes but overwrite exisiting values
const int off = (int)wb->bit_offset;
const int p = off / CHAR_BIT;
const int q = CHAR_BIT - 1 - off % CHAR_BIT;
wb->bit_buffer[p] &= ~(1 << q);
wb->bit_buffer[p] |= bit << q;
wb->bit_offset = off + 1;
}
void aom_wb_write_literal(struct aom_write_bit_buffer *wb, int data, int bits) {
assert(bits <= 31);
int bit;
for (bit = bits - 1; bit >= 0; bit--) aom_wb_write_bit(wb, (data >> bit) & 1);
}
void aom_wb_write_unsigned_literal(struct aom_write_bit_buffer *wb,
uint32_t data, int bits) {
assert(bits <= 32);
int bit;
for (bit = bits - 1; bit >= 0; bit--) aom_wb_write_bit(wb, (data >> bit) & 1);
}
void aom_wb_overwrite_literal(struct aom_write_bit_buffer *wb, int data,
int bits) {
int bit;
for (bit = bits - 1; bit >= 0; bit--)
aom_wb_overwrite_bit(wb, (data >> bit) & 1);
}
void aom_wb_write_inv_signed_literal(struct aom_write_bit_buffer *wb, int data,
int bits) {
aom_wb_write_literal(wb, data, bits + 1);
}
void aom_wb_write_uvlc(struct aom_write_bit_buffer *wb, uint32_t v) {
int64_t shift_val = ++v;
int leading_zeroes = 1;
assert(shift_val > 0);
while (shift_val >>= 1) leading_zeroes += 2;
aom_wb_write_literal(wb, 0, leading_zeroes >> 1);
aom_wb_write_unsigned_literal(wb, v, (leading_zeroes + 1) >> 1);
}
static void wb_write_primitive_quniform(struct aom_write_bit_buffer *wb,
uint16_t n, uint16_t v) {
if (n <= 1) return;
const int l = get_msb(n) + 1;
const int m = (1 << l) - n;
if (v < m) {
aom_wb_write_literal(wb, v, l - 1);
} else {
aom_wb_write_literal(wb, m + ((v - m) >> 1), l - 1);
aom_wb_write_bit(wb, (v - m) & 1);
}
}
static void wb_write_primitive_subexpfin(struct aom_write_bit_buffer *wb,
uint16_t n, uint16_t k, uint16_t v) {
int i = 0;
int mk = 0;
while (1) {
int b = (i ? k + i - 1 : k);
int a = (1 << b);
if (n <= mk + 3 * a) {
wb_write_primitive_quniform(wb, n - mk, v - mk);
break;
} else {
int t = (v >= mk + a);
aom_wb_write_bit(wb, t);
if (t) {
i = i + 1;
mk += a;
} else {
aom_wb_write_literal(wb, v - mk, b);
break;
}
}
}
}
static void wb_write_primitive_refsubexpfin(struct aom_write_bit_buffer *wb,
uint16_t n, uint16_t k,
uint16_t ref, uint16_t v) {
wb_write_primitive_subexpfin(wb, n, k, recenter_finite_nonneg(n, ref, v));
}
void aom_wb_write_signed_primitive_refsubexpfin(struct aom_write_bit_buffer *wb,
uint16_t n, uint16_t k,
int16_t ref, int16_t v) {
ref += n - 1;
v += n - 1;
const uint16_t scaled_n = (n << 1) - 1;
wb_write_primitive_refsubexpfin(wb, scaled_n, k, ref, v);
}
|
