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
|
/*
* Copyright (C) 2003-2009 The Music Player Daemon Project
* 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
*/
#ifndef PCM_VOLUME_H
#define PCM_VOLUME_H
#include "pcm_prng.h"
#include <stdint.h>
enum {
/** this value means "100% volume" */
PCM_VOLUME_1 = 1000,
};
struct audio_format;
/**
* Converts a float value (0.0 = silence, 1.0 = 100% volume) to an
* integer volume value (1000 = 100%).
*/
static inline int
pcm_float_to_volume(float volume)
{
return volume * PCM_VOLUME_1 + 0.5;
}
static inline int
pcm_dither(void)
{
static unsigned long state;
uint32_t r;
r = state = prng(state);
return (r & 511) - ((r >> 9) & 511);
}
void
pcm_volume(char *buffer, int bufferSize,
const struct audio_format *format,
int volume);
#endif
|
