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
|
/*
* 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.
*/
#include "config.h"
#if ENABLE(WEB_AUDIO)
#include "platform/audio/AudioDestination.h"
#include "platform/audio/AudioFIFO.h"
#include "platform/audio/AudioPullFIFO.h"
#include "public/platform/Platform.h"
namespace blink {
// Buffer size at which the web audio engine will render.
const unsigned renderBufferSize = 128;
// Size of the FIFO
const size_t fifoSize = 8192;
// Factory method: Chromium-implementation
PassOwnPtr<AudioDestination> AudioDestination::create(AudioIOCallback& callback, const String& inputDeviceId, unsigned numberOfInputChannels, unsigned numberOfOutputChannels, float sampleRate)
{
return adoptPtr(new AudioDestination(callback, inputDeviceId, numberOfInputChannels, numberOfOutputChannels, sampleRate));
}
AudioDestination::AudioDestination(AudioIOCallback& callback, const String& inputDeviceId, unsigned numberOfInputChannels, unsigned numberOfOutputChannels, float sampleRate)
: m_callback(callback)
, m_numberOfOutputChannels(numberOfOutputChannels)
, m_inputBus(AudioBus::create(numberOfInputChannels, renderBufferSize))
, m_renderBus(AudioBus::create(numberOfOutputChannels, renderBufferSize, false))
, m_sampleRate(sampleRate)
, m_isPlaying(false)
{
// Use the optimal buffer size recommended by the audio backend.
m_callbackBufferSize = Platform::current()->audioHardwareBufferSize();
#if OS(ANDROID)
// The optimum low-latency hardware buffer size is usually too small on Android for WebAudio to
// render without glitching. So, if it is small, use a larger size. If it was already large, use
// the requested size.
//
// Since WebAudio renders in 128-frame blocks, the small buffer sizes (144 for a Galaxy Nexus),
// cause significant processing jitter. Sometimes multiple blocks will processed, but other
// times will not be since the FIFO can satisfy the request. By using a larger
// callbackBufferSize, we smooth out the jitter.
const size_t kSmallBufferSize = 1024;
const size_t kDefaultCallbackBufferSize = 2048;
if (m_callbackBufferSize <= kSmallBufferSize)
m_callbackBufferSize = kDefaultCallbackBufferSize;
#endif
// Quick exit if the requested size is too large.
ASSERT(m_callbackBufferSize + renderBufferSize <= fifoSize);
if (m_callbackBufferSize + renderBufferSize > fifoSize)
return;
m_audioDevice = adoptPtr(Platform::current()->createAudioDevice(m_callbackBufferSize, numberOfInputChannels, numberOfOutputChannels, sampleRate, this, inputDeviceId));
ASSERT(m_audioDevice);
// Create a FIFO to handle the possibility of the callback size
// not being a multiple of the render size. If the FIFO already
// contains enough data, the data will be provided directly.
// Otherwise, the FIFO will call the provider enough times to
// satisfy the request for data.
m_fifo = adoptPtr(new AudioPullFIFO(*this, numberOfOutputChannels, fifoSize, renderBufferSize));
// Input buffering.
m_inputFifo = adoptPtr(new AudioFIFO(numberOfInputChannels, fifoSize));
// If the callback size does not match the render size, then we need to buffer some
// extra silence for the input. Otherwise, we can over-consume the input FIFO.
if (m_callbackBufferSize != renderBufferSize) {
// FIXME: handle multi-channel input and don't hard-code to stereo.
RefPtr<AudioBus> silence = AudioBus::create(2, renderBufferSize);
m_inputFifo->push(silence.get());
}
}
AudioDestination::~AudioDestination()
{
stop();
}
void AudioDestination::start()
{
if (!m_isPlaying && m_audioDevice) {
m_audioDevice->start();
m_isPlaying = true;
}
}
void AudioDestination::stop()
{
if (m_isPlaying && m_audioDevice) {
m_audioDevice->stop();
m_isPlaying = false;
}
}
float AudioDestination::hardwareSampleRate()
{
return static_cast<float>(Platform::current()->audioHardwareSampleRate());
}
unsigned long AudioDestination::maxChannelCount()
{
return static_cast<float>(Platform::current()->audioHardwareOutputChannels());
}
void AudioDestination::render(const WebVector<float*>& sourceData, const WebVector<float*>& audioData, size_t numberOfFrames)
{
bool isNumberOfChannelsGood = audioData.size() == m_numberOfOutputChannels;
if (!isNumberOfChannelsGood) {
ASSERT_NOT_REACHED();
return;
}
bool isBufferSizeGood = numberOfFrames == m_callbackBufferSize;
if (!isBufferSizeGood) {
ASSERT_NOT_REACHED();
return;
}
// Buffer optional live input.
if (sourceData.size() >= 2) {
// FIXME: handle multi-channel input and don't hard-code to stereo.
RefPtr<AudioBus> wrapperBus = AudioBus::create(2, numberOfFrames, false);
wrapperBus->setChannelMemory(0, sourceData[0], numberOfFrames);
wrapperBus->setChannelMemory(1, sourceData[1], numberOfFrames);
m_inputFifo->push(wrapperBus.get());
}
for (unsigned i = 0; i < m_numberOfOutputChannels; ++i)
m_renderBus->setChannelMemory(i, audioData[i], numberOfFrames);
m_fifo->consume(m_renderBus.get(), numberOfFrames);
}
void AudioDestination::provideInput(AudioBus* bus, size_t framesToProcess)
{
AudioBus* sourceBus = 0;
if (m_inputFifo->framesInFifo() >= framesToProcess) {
m_inputFifo->consume(m_inputBus.get(), framesToProcess);
sourceBus = m_inputBus.get();
}
m_callback.render(sourceBus, bus, framesToProcess);
}
} // namespace blink
#endif // ENABLE(WEB_AUDIO)
|
