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
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
|
/**
* OpenAL cross platform audio library
* Copyright (C) 2010 by Chris Robinson
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
* Or go to http://www.gnu.org/copyleft/lgpl.html
*/
#include "config.h"
#include <stdlib.h>
#include "alMain.h"
#include "AL/al.h"
#include "AL/alc.h"
typedef struct {
volatile int killNow;
ALvoid *thread;
} null_data;
static const ALCchar nullDevice[] = "No Output";
static ALuint NullProc(ALvoid *ptr)
{
ALCdevice *Device = (ALCdevice*)ptr;
null_data *data = (null_data*)Device->ExtraData;
ALuint now, start;
ALuint64 avail, done;
const ALuint restTime = (ALuint64)Device->UpdateSize * 1000 /
Device->Frequency / 2;
done = 0;
start = timeGetTime();
while(!data->killNow && Device->Connected)
{
now = timeGetTime();
avail = (ALuint64)(now-start) * Device->Frequency / 1000;
if(avail < done)
{
/* Timer wrapped (50 days???). Add the remainder of the cycle to
* the available count and reset the number of samples done */
avail += ((ALuint64)1<<32)*Device->Frequency/1000 - done;
done = 0;
}
if(avail-done < Device->UpdateSize)
{
Sleep(restTime);
continue;
}
while(avail-done >= Device->UpdateSize)
{
aluMixData(Device, NULL, Device->UpdateSize);
done += Device->UpdateSize;
}
}
return 0;
}
static ALCenum null_open_playback(ALCdevice *device, const ALCchar *deviceName)
{
null_data *data;
if(!deviceName)
deviceName = nullDevice;
else if(strcmp(deviceName, nullDevice) != 0)
return ALC_INVALID_VALUE;
data = (null_data*)calloc(1, sizeof(*data));
device->DeviceName = strdup(deviceName);
device->ExtraData = data;
return ALC_NO_ERROR;
}
static void null_close_playback(ALCdevice *device)
{
null_data *data = (null_data*)device->ExtraData;
free(data);
device->ExtraData = NULL;
}
static ALCboolean null_reset_playback(ALCdevice *device)
{
SetDefaultWFXChannelOrder(device);
return ALC_TRUE;
}
static ALCboolean null_start_playback(ALCdevice *device)
{
null_data *data = (null_data*)device->ExtraData;
data->thread = StartThread(NullProc, device);
if(data->thread == NULL)
return ALC_FALSE;
return ALC_TRUE;
}
static void null_stop_playback(ALCdevice *device)
{
null_data *data = (null_data*)device->ExtraData;
if(!data->thread)
return;
data->killNow = 1;
StopThread(data->thread);
data->thread = NULL;
data->killNow = 0;
}
static ALint64 null_get_latency(ALCdevice *device)
{
/* FIXME: Time until next update + "safe" offset */
(void)device;
return 0;
}
static const BackendFuncs null_funcs = {
null_open_playback,
null_close_playback,
null_reset_playback,
null_start_playback,
null_stop_playback,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
null_get_latency
};
ALCboolean alc_null_init(BackendFuncs *func_list)
{
*func_list = null_funcs;
return ALC_TRUE;
}
void alc_null_deinit(void)
{
}
void alc_null_probe(enum DevProbe type)
{
switch(type)
{
case ALL_DEVICE_PROBE:
AppendAllDevicesList(nullDevice);
break;
case CAPTURE_DEVICE_PROBE:
break;
}
}
|
