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
|
// Copyright 2013 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 "media/blink/webaudiosourceprovider_impl.h"
#include <vector>
#include "base/bind.h"
#include "base/callback_helpers.h"
#include "base/logging.h"
#include "base/macros.h"
#include "media/base/bind_to_current_loop.h"
#include "third_party/WebKit/public/platform/WebAudioSourceProviderClient.h"
using blink::WebVector;
namespace media {
namespace {
// Simple helper class for Try() locks. Lock is Try()'d on construction and
// must be checked via the locked() attribute. If acquisition was successful
// the lock will be released upon destruction.
// TODO(dalecurtis): This should probably move to base/ if others start using
// this pattern.
class AutoTryLock {
public:
explicit AutoTryLock(base::Lock& lock)
: lock_(lock),
acquired_(lock_.Try()) {}
bool locked() const { return acquired_; }
~AutoTryLock() {
if (acquired_) {
lock_.AssertAcquired();
lock_.Release();
}
}
private:
base::Lock& lock_;
const bool acquired_;
DISALLOW_COPY_AND_ASSIGN(AutoTryLock);
};
} // namespace
WebAudioSourceProviderImpl::WebAudioSourceProviderImpl(
const scoped_refptr<RestartableAudioRendererSink>& sink)
: channels_(0),
sample_rate_(0),
volume_(1.0),
state_(kStopped),
renderer_(NULL),
client_(NULL),
sink_(sink),
weak_factory_(this) {}
WebAudioSourceProviderImpl::~WebAudioSourceProviderImpl() {
}
void WebAudioSourceProviderImpl::setClient(
blink::WebAudioSourceProviderClient* client) {
base::AutoLock auto_lock(sink_lock_);
if (client && client != client_) {
// Detach the audio renderer from normal playback.
sink_->Stop();
// The client will now take control by calling provideInput() periodically.
client_ = client;
set_format_cb_ = BindToCurrentLoop(base::Bind(
&WebAudioSourceProviderImpl::OnSetFormat, weak_factory_.GetWeakPtr()));
// If |renderer_| is set, then run |set_format_cb_| to send |client_|
// the current format info. If |renderer_| is not set, then |set_format_cb_|
// will get called when Initialize() is called.
// Note: Always using |set_format_cb_| ensures we have the same
// locking order when calling into |client_|.
if (renderer_)
base::ResetAndReturn(&set_format_cb_).Run();
} else if (!client && client_) {
// Restore normal playback.
client_ = NULL;
sink_->SetVolume(volume_);
if (state_ >= kStarted)
sink_->Start();
if (state_ >= kPlaying)
sink_->Play();
}
}
void WebAudioSourceProviderImpl::provideInput(
const WebVector<float*>& audio_data, size_t number_of_frames) {
if (!bus_wrapper_ ||
static_cast<size_t>(bus_wrapper_->channels()) != audio_data.size()) {
bus_wrapper_ = AudioBus::CreateWrapper(static_cast<int>(audio_data.size()));
}
bus_wrapper_->set_frames(static_cast<int>(number_of_frames));
for (size_t i = 0; i < audio_data.size(); ++i)
bus_wrapper_->SetChannelData(static_cast<int>(i), audio_data[i]);
// Use a try lock to avoid contention in the real-time audio thread.
AutoTryLock auto_try_lock(sink_lock_);
if (!auto_try_lock.locked() || state_ != kPlaying) {
// Provide silence if we failed to acquire the lock or the source is not
// running.
bus_wrapper_->Zero();
return;
}
DCHECK(renderer_);
DCHECK(client_);
DCHECK_EQ(channels_, bus_wrapper_->channels());
const int frames = renderer_->Render(bus_wrapper_.get(), 0, 0);
if (frames < static_cast<int>(number_of_frames)) {
bus_wrapper_->ZeroFramesPartial(
frames,
static_cast<int>(number_of_frames - frames));
}
bus_wrapper_->Scale(volume_);
}
void WebAudioSourceProviderImpl::Start() {
base::AutoLock auto_lock(sink_lock_);
DCHECK(renderer_);
DCHECK_EQ(state_, kStopped);
state_ = kStarted;
if (!client_)
sink_->Start();
}
void WebAudioSourceProviderImpl::Stop() {
base::AutoLock auto_lock(sink_lock_);
state_ = kStopped;
if (!client_)
sink_->Stop();
}
void WebAudioSourceProviderImpl::Play() {
base::AutoLock auto_lock(sink_lock_);
DCHECK_EQ(state_, kStarted);
state_ = kPlaying;
if (!client_)
sink_->Play();
}
void WebAudioSourceProviderImpl::Pause() {
base::AutoLock auto_lock(sink_lock_);
DCHECK(state_ == kPlaying || state_ == kStarted);
state_ = kStarted;
if (!client_)
sink_->Pause();
}
bool WebAudioSourceProviderImpl::SetVolume(double volume) {
base::AutoLock auto_lock(sink_lock_);
volume_ = volume;
if (!client_)
sink_->SetVolume(volume);
return true;
}
OutputDevice* WebAudioSourceProviderImpl::GetOutputDevice() {
base::AutoLock auto_lock(sink_lock_);
return sink_->GetOutputDevice();
}
void WebAudioSourceProviderImpl::Initialize(
const AudioParameters& params,
RenderCallback* renderer) {
base::AutoLock auto_lock(sink_lock_);
renderer_ = renderer;
DCHECK_EQ(state_, kStopped);
sink_->Initialize(params, renderer);
// Keep track of the format in case the client hasn't yet been set.
channels_ = params.channels();
sample_rate_ = params.sample_rate();
if (!set_format_cb_.is_null())
base::ResetAndReturn(&set_format_cb_).Run();
}
void WebAudioSourceProviderImpl::OnSetFormat() {
base::AutoLock auto_lock(sink_lock_);
if (!client_)
return;
// Inform Blink about the audio stream format.
client_->setFormat(channels_, sample_rate_);
}
} // namespace media
|
