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
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
|
#include "pcm.h"
#include <inttypes.h>
#include <stdlib.h>
/*
* Functions to convert PCM to 16-bit signed little-endian stereo
*
* Conversion for 8-bit PCM):
* 1. phase
* unsigned -> signed
* mono -> stereo
* 8 -> 16
*
* Conversion for 16-bit PCM:
* 1. phase
* be -> le
* unsigned -> signed
*
* 2. phase
* mono -> stereo
*
* There's no reason to split 8-bit conversion to 2 phases because we need to
* use separate buffer for 8->16 conversion anyway.
*
* Conversions for 16-bit stereo can be done in place. 16-bit mono needs to be
* converted to stereo so it's worthwhile to split the conversion to 2 phases.
*/
static void convert_u8_1ch_to_s16_2ch(char *dst, const char *src, int count)
{
int16_t *d = (int16_t *)dst;
const uint8_t *s = (const uint8_t *)src;
int i, j = 0;
for (i = 0; i < count; i++) {
int16_t sample = s[i] << 8;
sample -= 32768;
d[j++] = sample;
d[j++] = sample;
}
}
static void convert_s8_1ch_to_s16_2ch(char *dst, const char *src, int count)
{
int16_t *d = (int16_t *)dst;
const int8_t *s = (const int8_t *)src;
int i, j = 0;
for (i = 0; i < count; i++) {
int16_t sample = s[i] << 8;
d[j++] = sample;
d[j++] = sample;
}
}
static void convert_u8_2ch_to_s16_2ch(char *dst, const char *src, int count)
{
int16_t *d = (int16_t *)dst;
const int8_t *s = (const int8_t *)src;
int i;
for (i = 0; i < count; i++) {
int16_t sample = s[i] << 8;
sample -= 32768;
d[i] = sample;
}
}
static void convert_s8_2ch_to_s16_2ch(char *dst, const char *src, int count)
{
int16_t *d = (int16_t *)dst;
const int8_t *s = (const int8_t *)src;
int i;
for (i = 0; i < count; i++) {
int16_t sample = s[i] << 8;
d[i] = sample;
}
}
static void convert_u16_le_to_s16_le(char *buf, int count)
{
int16_t *b = (int16_t *)buf;
int i;
for (i = 0; i < count; i++) {
int sample = (uint16_t)b[i];
sample -= 32768;
b[i] = sample;
}
}
static void convert_u16_be_to_s16_le(char *buf, int count)
{
int16_t *b = (int16_t *)buf;
int i;
for (i = 0; i < count; i++) {
uint16_t u = b[i];
int sample;
u = (u << 8) | (u >> 8);
sample = (int)u - 32768;
b[i] = sample;
}
}
static void convert_s16_be_to_s16_le(char *buf, int count)
{
int16_t *b = (int16_t *)buf;
int i;
for (i = 0; i < count; i++) {
uint16_t sample = b[i];
b[i] = (sample << 8) | (sample >> 8);
}
}
static void convert_16_1ch_to_16_2ch(char *dst, const char *src, int count)
{
int16_t *d = (int16_t *)dst;
const int16_t *s = (const int16_t *)src;
int i, j = 0;
for (i = 0; i < count; i++) {
d[j++] = s[i];
d[j++] = s[i];
}
}
/* index is ((bits >> 2) & 4) | (is_signed << 1) | (channels - 1) */
pcm_conv_func pcm_conv[8] = {
convert_u8_1ch_to_s16_2ch,
convert_u8_2ch_to_s16_2ch,
convert_s8_1ch_to_s16_2ch,
convert_s8_2ch_to_s16_2ch,
convert_16_1ch_to_16_2ch,
NULL,
convert_16_1ch_to_16_2ch,
NULL
};
/* index is ((bits >> 2) & 4) | (is_signed << 1) | bigendian */
pcm_conv_in_place_func pcm_conv_in_place[8] = {
NULL,
NULL,
NULL,
NULL,
convert_u16_le_to_s16_le,
convert_u16_be_to_s16_le,
NULL,
convert_s16_be_to_s16_le
};
|
