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
|
/*
* Copyright (C) 2010 Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_AUDIO_DESTINATION_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_AUDIO_DESTINATION_H_
#include <memory>
#include "base/memory/scoped_refptr.h"
#include "base/single_thread_task_runner.h"
#include "third_party/blink/public/platform/web_audio_device.h"
#include "third_party/blink/public/platform/web_vector.h"
#include "third_party/blink/renderer/platform/audio/audio_bus.h"
#include "third_party/blink/renderer/platform/audio/audio_io_callback.h"
#include "third_party/blink/renderer/platform/audio/media_multi_channel_resampler.h"
#include "third_party/blink/renderer/platform/scheduler/public/thread.h"
#include "third_party/blink/renderer/platform/wtf/threading_primitives.h"
#include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
#include "third_party/blink/renderer/platform/wtf/thread_safe_ref_counted.h"
namespace blink {
class PushPullFIFO;
class WebAudioLatencyHint;
// The AudioDestination class is an audio sink interface between the media
// renderer and the Blink's WebAudio module. It has a FIFO to adapt the
// different processing block sizes of WebAudio renderer and actual hardware
// audio callback.
//
// Currently AudioDestination supports two types of threading models:
// - Single-thread (default): process the entire WebAudio render call chain by
// AudioDeviceThread.
// - Dual-thread (experimental): Use WebThread for the WebAudio rendering with
// AudioWorkletThread.
class PLATFORM_EXPORT AudioDestination
: public ThreadSafeRefCounted<AudioDestination>,
public WebAudioDevice::RenderCallback {
USING_FAST_MALLOC(AudioDestination);
public:
AudioDestination(AudioIOCallback&,
unsigned number_of_output_channels,
const WebAudioLatencyHint&,
base::Optional<float> context_sample_rate);
~AudioDestination() override;
static scoped_refptr<AudioDestination> Create(
AudioIOCallback&,
unsigned number_of_output_channels,
const WebAudioLatencyHint&,
base::Optional<float> context_sample_rate);
// The actual render function (WebAudioDevice::RenderCallback) isochronously
// invoked by the media renderer. This is never called after Stop() is called.
void Render(const WebVector<float*>& destination_data,
size_t number_of_frames,
double delay,
double delay_timestamp,
size_t prior_frames_skipped) override;
// The actual render request to the WebAudio destination node. This method
// can be invoked on both AudioDeviceThread (single-thread rendering) and
// AudioWorkletThread (dual-thread rendering).
void RequestRender(size_t frames_requested,
size_t frames_to_render,
double delay,
double delay_timestamp,
size_t prior_frames_skipped);
virtual void Start();
virtual void Stop();
virtual void Pause();
virtual void Resume();
// Sets the destination for worklet operation, but does not start rendering.
void SetWorkletTaskRunner(
scoped_refptr<base::SingleThreadTaskRunner> worklet_task_runner);
// Starts rendering in the AudioWorklet mode.
void StartWithWorkletTaskRunner(
scoped_refptr<base::SingleThreadTaskRunner> worklet_task_runner);
// Getters must be accessed from the main thread.
uint32_t CallbackBufferSize() const;
bool IsPlaying();
// This is the context sample rate, not the device one.
double SampleRate() const { return context_sample_rate_; }
// Returns the audio buffer size in frames used by the underlying audio
// hardware.
int FramesPerBuffer() const;
// The information from the actual audio hardware. (via Platform::current)
static float HardwareSampleRate();
static uint32_t MaxChannelCount();
// Sets the detect silence flag for |web_audio_device_|.
void SetDetectSilence(bool detect_silence);
private:
// Represents the current state of the underlying |WebAudioDevice| object
// (RendererWebAudioDeviceImpl).
enum DeviceState {
kRunning,
kPaused,
kStopped,
};
void SetDeviceState(DeviceState);
// Provide input to the resampler (if used).
void ProvideResamplerInput(int resampler_frame_delay, AudioBus* dest);
// Check if the buffer size chosen by the WebAudioDevice is too large.
bool CheckBufferSize();
size_t HardwareBufferSize();
// Accessed by the main thread.
std::unique_ptr<WebAudioDevice> web_audio_device_;
const unsigned number_of_output_channels_;
uint32_t callback_buffer_size_;
// The task runner for AudioWorklet operation. This is only valid when
// the AudioWorklet is activated.
scoped_refptr<base::SingleThreadTaskRunner> worklet_task_runner_;
// Can be accessed by both threads: resolves the buffer size mismatch between
// the WebAudio engine and the callback function from the actual audio device.
std::unique_ptr<PushPullFIFO> fifo_;
// Accessed by device thread: to pass the data from FIFO to the device.
scoped_refptr<AudioBus> output_bus_;
// Accessed by rendering thread: to push the rendered result from WebAudio
// graph into the FIFO.
scoped_refptr<AudioBus> render_bus_;
// Accessed by rendering thread: the render callback function of WebAudio
// engine. (i.e. DestinationNode)
AudioIOCallback& callback_;
// Accessed by rendering thread.
size_t frames_elapsed_;
// The sample rate used for rendering the Web Audio graph.
float context_sample_rate_;
// Used for resampling if the Web Audio sample rate differs from the platform
// one.
std::unique_ptr<MediaMultiChannelResampler> resampler_;
std::unique_ptr<media::AudioBus> resampler_bus_;
// Required for RequestRender and also in the resampling callback (if used).
AudioIOPosition output_position_;
AudioCallbackMetricReporter metric_reporter_;
// This protects |device_state_| below.
mutable Mutex state_change_lock_;
// Modified only on the main thread, so it can be read without holding a lock
// there.
DeviceState device_state_;
DISALLOW_COPY_AND_ASSIGN(AudioDestination);
};
} // namespace blink
#endif // THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_AUDIO_DESTINATION_H_
|
