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
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
|
// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "chrome/browser/chromeos/audio_handler.h"
#include <math.h>
#include "base/logging.h"
#include "base/memory/singleton.h"
#include "chrome/browser/chromeos/audio_mixer_alsa.h"
#include "content/browser/browser_thread.h"
namespace chromeos {
namespace {
const double kMinVolumeDb = -90.0;
// Choosing 6.0dB here instead of 0dB to give user chance to amplify audio some
// in case sounds or their setup is too quiet for them.
const double kMaxVolumeDb = 6.0;
// A value of less than one adjusts quieter volumes in larger steps (giving
// finer resolution in the higher volumes).
const double kVolumeBias = 0.5;
// If a connection is lost, we try again this many times
const int kMaxReconnectTries = 4;
} // namespace
// chromeos: This class will set the volume using ALSA to adjust volume and
// mute, and handle the volume level logic.
double AudioHandler::GetVolumePercent() {
if (!VerifyMixerConnection())
return 0;
return VolumeDbToPercent(mixer_->GetVolumeDb());
}
// Set volume using our internal 0-100% range. Notice 0% is a special case of
// silence, so we set the mixer volume to kSilenceDb instead of min_volume_db_.
void AudioHandler::SetVolumePercent(double volume_percent) {
if (!VerifyMixerConnection())
return;
DCHECK(volume_percent >= 0.0);
double vol_db;
if (volume_percent <= 0)
vol_db = AudioMixer::kSilenceDb;
else
vol_db = PercentToVolumeDb(volume_percent);
mixer_->SetVolumeDb(vol_db);
}
void AudioHandler::AdjustVolumeByPercent(double adjust_by_percent) {
if (!VerifyMixerConnection())
return;
DVLOG(1) << "Adjusting Volume by " << adjust_by_percent << " percent";
double volume = mixer_->GetVolumeDb();
double pct = VolumeDbToPercent(volume);
if (pct < 0)
pct = 0;
pct = pct + adjust_by_percent;
if (pct > 100.0)
pct = 100.0;
double new_volume;
if (pct <= 0.1)
new_volume = AudioMixer::kSilenceDb;
else
new_volume = PercentToVolumeDb(pct);
if (new_volume != volume)
mixer_->SetVolumeDb(new_volume);
}
bool AudioHandler::IsMute() {
if (!VerifyMixerConnection())
return false;
return mixer_->IsMute();
}
void AudioHandler::SetMute(bool do_mute) {
if (!VerifyMixerConnection())
return;
DVLOG(1) << "Setting Mute to " << do_mute;
mixer_->SetMute(do_mute);
}
void AudioHandler::Disconnect() {
mixer_.reset();
}
bool AudioHandler::TryToConnect(bool async) {
if (mixer_type_ == MIXER_TYPE_ALSA) {
VLOG(1) << "Trying to connect to ALSA";
mixer_.reset(new AudioMixerAlsa());
} else {
VLOG(1) << "Cannot find valid volume mixer";
mixer_.reset();
return false;
}
if (async) {
mixer_->Init(NewCallback(this, &AudioHandler::OnMixerInitialized));
} else {
if (!mixer_->InitSync()) {
VLOG(1) << "Unable to reconnect to Mixer";
return false;
}
}
return true;
}
static void ClipVolume(double* min_volume, double* max_volume) {
if (*min_volume < kMinVolumeDb)
*min_volume = kMinVolumeDb;
if (*max_volume > kMaxVolumeDb)
*max_volume = kMaxVolumeDb;
}
void AudioHandler::OnMixerInitialized(bool success) {
connected_ = success;
DVLOG(1) << "OnMixerInitialized, success = " << success;
if (connected_) {
if (mixer_->GetVolumeLimits(&min_volume_db_, &max_volume_db_)) {
ClipVolume(&min_volume_db_, &max_volume_db_);
}
return;
}
VLOG(1) << "Unable to connect to mixer";
mixer_type_ = MIXER_TYPE_NONE;
// This frees the mixer on the UI thread
BrowserThread::PostTask(
BrowserThread::UI, FROM_HERE,
NewRunnableMethod(this, &AudioHandler::TryToConnect, true));
}
AudioHandler::AudioHandler()
: connected_(false),
reconnect_tries_(0),
max_volume_db_(kMaxVolumeDb),
min_volume_db_(kMinVolumeDb),
mixer_type_(MIXER_TYPE_ALSA) {
// Start trying to connect to mixers asynchronously, starting with the current
// mixer_type_. If the connection fails, another TryToConnect() for the next
// mixer will be posted at that time.
TryToConnect(true);
}
AudioHandler::~AudioHandler() {
Disconnect();
};
bool AudioHandler::VerifyMixerConnection() {
if (mixer_ == NULL)
return false;
AudioMixer::State mixer_state = mixer_->GetState();
if (mixer_state == AudioMixer::READY)
return true;
if (connected_) {
// Something happened and the mixer is no longer valid after having been
// initialized earlier.
connected_ = false;
LOG(ERROR) << "Lost connection to mixer";
} else {
LOG(ERROR) << "Mixer not valid";
}
if ((mixer_state == AudioMixer::INITIALIZING) ||
(mixer_state == AudioMixer::SHUTTING_DOWN))
return false;
if (reconnect_tries_ < kMaxReconnectTries) {
reconnect_tries_++;
VLOG(1) << "Re-connecting to mixer attempt " << reconnect_tries_ << "/"
<< kMaxReconnectTries;
connected_ = TryToConnect(false);
if (connected_) {
reconnect_tries_ = 0;
return true;
}
LOG(ERROR) << "Unable to re-connect to mixer";
}
return false;
}
// VolumeDbToPercent() and PercentToVolumeDb() conversion functions allow us
// complete control over how the 0 to 100% range is mapped to actual loudness.
// Volume range is from min_volume_db_ at just above 0% to max_volume_db_
// at 100% with a special case at 0% which maps to kSilenceDb.
//
// The mapping is confined to these two functions to make it easy to adjust and
// have everything else just work. The range is biased to give finer resolution
// in the higher volumes if kVolumeBias is less than 1.0.
// static
double AudioHandler::VolumeDbToPercent(double volume_db) const {
if (volume_db < min_volume_db_)
return 0;
return 100.0 * pow((volume_db - min_volume_db_) /
(max_volume_db_ - min_volume_db_), 1/kVolumeBias);
}
// static
double AudioHandler::PercentToVolumeDb(double volume_percent) const {
return pow(volume_percent / 100.0, kVolumeBias) *
(max_volume_db_ - min_volume_db_) + min_volume_db_;
}
// static
AudioHandler* AudioHandler::GetInstance() {
return Singleton<AudioHandler>::get();
}
} // namespace chromeos
|
