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
176
177
178
179
180
181
182
183
|
/*
** ClanLib SDK
** Copyright (c) 1997-2005 The ClanLib Team
**
** This software is provided 'as-is', without any express or implied
** warranty. In no event will the authors be held liable for any damages
** arising from the use of this software.
**
** Permission is granted to anyone to use this software for any purpose,
** including commercial applications, and to alter it and redistribute it
** freely, subject to the following restrictions:
**
** 1. The origin of this software must not be misrepresented; you must not
** claim that you wrote the original software. If you use this software
** in a product, an acknowledgment in the product documentation would be
** appreciated but is not required.
** 2. Altered source versions must be plainly marked as such, and must not be
** misrepresented as being the original software.
** 3. This notice may not be removed or altered from any source distribution.
**
** Note: Some of the libraries ClanLib may link to may have additional
** requirements or restrictions.
**
** File Author(s):
**
** Magnus Norddahl
** Sean Heber - implemented ring buffer
** (if your name is missing here, please add it)
*/
#include "Sound/precomp.h"
#include "soundoutput_macosx.h"
#include "API/Core/System/error.h"
#include "API/Core/System/cl_assert.h"
#include "API/Core/System/system.h"
#include "API/Core/System/log.h"
/////////////////////////////////////////////////////////////////////////////
// CL_SoundOutput_MacOSX construction:
CL_SoundOutput_MacOSX::CL_SoundOutput_MacOSX(int frequency) :
CL_SoundOutput_Generic(frequency), playing(false)
{
UInt32 size;
OSStatus result;
// Find default output device:
device = kAudioDeviceUnknown;
size = sizeof(AudioDeviceID);
result = AudioHardwareGetProperty(kAudioHardwarePropertyDefaultOutputDevice, &size, &device);
if (result != noErr)
return;
// Get buffer size for device:
device_buffer_size = 0;
size = sizeof(UInt32);
result = AudioDeviceGetProperty(device, 0, false, kAudioDevicePropertyBufferSize, &size, &device_buffer_size);
if (result != noErr)
return;
// Get device format description:
size = sizeof(AudioStreamBasicDescription);
memset(&device_format, 0, size);
result = AudioDeviceGetProperty(device, 0, false, kAudioDevicePropertyStreamFormat, &size, &device_format);
if (result != noErr)
return;
/*
printf("sampleRate %g\n", device_format.mSampleRate);
printf("mFormatFlags %08X\n", device_format.mFormatFlags);
printf("mBytesPerPacket %d\n", device_format.mBytesPerPacket);
printf("mFramesPerPacket %d\n", device_format.mFramesPerPacket);
printf("mChannelsPerFrame %d\n", device_format.mChannelsPerFrame);
printf("mBytesPerFrame %d\n", device_format.mBytesPerFrame);
printf("mBitsPerChannel %d\n", device_format.mBitsPerChannel);
*/
if (device_format.mFormatID != kAudioFormatLinearPCM)
return;
mixing_frequency = int(device_format.mSampleRate);
// configure the fragment ring buffer
fragment_buffer.resize(10); // <--- this number affects audio lag (must be >= 2!)
fragment_insert_position = 0;
fragment_play_position = 1;
int frag_size = get_fragment_size();
for (unsigned int i=0; i<fragment_buffer.size(); i++ )
{
fragment_buffer[i] = new float[frag_size*2];
bzero(fragment_buffer[i],sizeof(float)*frag_size*2);
}
result = AudioDeviceAddIOProc(device, &CL_SoundOutput_MacOSX::audio_handler, this);
if (result != noErr)
return;
result = AudioDeviceStart(device, &CL_SoundOutput_MacOSX::audio_handler);
if (result != noErr)
return;
playing = true;
start_mixer_thread();
}
CL_SoundOutput_MacOSX::~CL_SoundOutput_MacOSX()
{
stop_mixer_thread();
if (playing)
{
AudioDeviceStop(device, &CL_SoundOutput_MacOSX::audio_handler);
AudioDeviceRemoveIOProc(device, &CL_SoundOutput_MacOSX::audio_handler);
playing = false;
}
}
/////////////////////////////////////////////////////////////////////////////
// CL_SoundOutput_MacOSX attributes:
/////////////////////////////////////////////////////////////////////////////
// CL_SoundOutput_MacOSX operations:
void CL_SoundOutput_MacOSX::silence()
{
}
int CL_SoundOutput_MacOSX::get_fragment_size()
{
int frag_size = device_buffer_size / device_format.mBytesPerFrame;
return frag_size;
}
void CL_SoundOutput_MacOSX::write_fragment(short *data)
{
int frag_size = get_fragment_size();
float *frag_data = fragment_buffer[fragment_insert_position];
for (int i=0; i<frag_size*2; i++)
frag_data[i] = data[i]/32768.0f;
fragment_insert_position++;
if (fragment_insert_position == fragment_buffer.size() )
fragment_insert_position = 0;
}
void CL_SoundOutput_MacOSX::wait()
{
while (true)
{
// note: this equality is perhaps dangerous due to threading issue
// see note down in audio_handler below for why.
bool buffer_is_full = fragment_insert_position == fragment_play_position;
if (!buffer_is_full) break;
CL_System::sleep(10);
}
}
/////////////////////////////////////////////////////////////////////////////
// CL_SoundOutput_MacOSX implementation:
OSStatus CL_SoundOutput_MacOSX::audio_handler(
AudioDeviceID in_device,
const AudioTimeStamp *in_now,
const AudioBufferList *in_input_data,
const AudioTimeStamp *in_input_time,
AudioBufferList *out_output_data,
const AudioTimeStamp *in_output_time,
void *user_data)
{
CL_SoundOutput_MacOSX *self = (CL_SoundOutput_MacOSX *) user_data;
float *data = (float *) out_output_data->mBuffers[0].mData;
bcopy(self->fragment_buffer[self->fragment_play_position], data, sizeof(float)*self->get_fragment_size()*2);
// this is sort of dangerous in that there's no mutex here and the value is compared
// in another thread above (see above), but I found a mutex introduces a slight lag
// and sometimes that appears to be problematic (mostly when cpu is pegged) - I guess
// we shall see if it is an issue or not...
self->fragment_play_position++;
if (self->fragment_play_position == self->fragment_buffer.size())
self->fragment_play_position = 0;
return noErr;
}
|
