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
|
/* the Music Player Daemon (MPD)
* Copyright (C) 2003-2007 by Warren Dukes (warren.dukes@gmail.com)
* Copyright (C) 2008 Max Kellermann <max@duempel.org>
* This project's homepage is: http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "pcm_resample.h"
#include "gcc.h"
#include <assert.h>
/* resampling code blatantly ripped from ESD */
size_t
pcm_resample_16(uint8_t channels,
unsigned src_rate,
const int16_t *src_buffer, mpd_unused size_t src_size,
unsigned dest_rate,
int16_t *dest_buffer, size_t dest_size,
mpd_unused struct pcm_resample_state *state)
{
unsigned src_pos, dest_pos = 0;
unsigned dest_samples = dest_size / sizeof(*dest_buffer);
assert((src_size % (sizeof(*src_buffer) * channels)) == 0);
assert((dest_size % (sizeof(*dest_buffer) * channels)) == 0);
switch (channels) {
case 1:
while (dest_pos < dest_samples) {
src_pos = dest_pos * src_rate / dest_rate;
dest_buffer[dest_pos++] = src_buffer[src_pos];
}
break;
case 2:
while (dest_pos < dest_samples) {
src_pos = dest_pos * src_rate / dest_rate;
src_pos &= ~1;
dest_buffer[dest_pos++] = src_buffer[src_pos];
dest_buffer[dest_pos++] = src_buffer[src_pos + 1];
}
break;
}
return dest_size;
}
size_t
pcm_resample_24(uint8_t channels,
unsigned src_rate,
const int32_t *src_buffer, mpd_unused size_t src_size,
unsigned dest_rate,
int32_t *dest_buffer, size_t dest_size,
mpd_unused struct pcm_resample_state *state)
{
unsigned src_pos, dest_pos = 0;
unsigned dest_samples = dest_size / sizeof(*dest_buffer);
switch (channels) {
case 1:
while (dest_pos < dest_samples) {
src_pos = dest_pos * src_rate / dest_rate;
dest_buffer[dest_pos++] = src_buffer[src_pos];
}
break;
case 2:
while (dest_pos < dest_samples) {
src_pos = dest_pos * src_rate / dest_rate;
src_pos &= ~1;
dest_buffer[dest_pos++] = src_buffer[src_pos];
dest_buffer[dest_pos++] = src_buffer[src_pos + 1];
}
break;
}
return dest_size;
}
|
