1/*
2 * Copyright (C) 2010, Google Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
16 * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
17 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
18 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
19 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
20 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
22 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 */
24
25#include "config.h"
26
27#if ENABLE(WEB_AUDIO)
28
29#include "AudioResampler.h"
30
31#include "AudioBus.h"
32#include <algorithm>
33#include <wtf/MathExtras.h>
34
35namespace WebCore {
36
37const double AudioResampler::MaxRate = 8.0;
38
39AudioResampler::AudioResampler()
40 : m_rate(1.0)
41{
42 m_kernels.append(std::make_unique<AudioResamplerKernel>(this));
43 m_sourceBus = AudioBus::create(1, 0, false);
44}
45
46AudioResampler::AudioResampler(unsigned numberOfChannels)
47 : m_rate(1.0)
48{
49 for (unsigned i = 0; i < numberOfChannels; ++i)
50 m_kernels.append(std::make_unique<AudioResamplerKernel>(this));
51
52 m_sourceBus = AudioBus::create(numberOfChannels, 0, false);
53}
54
55void AudioResampler::configureChannels(unsigned numberOfChannels)
56{
57 unsigned currentSize = m_kernels.size();
58 if (numberOfChannels == currentSize)
59 return; // already setup
60
61 // First deal with adding or removing kernels.
62 if (numberOfChannels > currentSize) {
63 for (unsigned i = currentSize; i < numberOfChannels; ++i)
64 m_kernels.append(std::make_unique<AudioResamplerKernel>(this));
65 } else
66 m_kernels.resize(numberOfChannels);
67
68 // Reconfigure our source bus to the new channel size.
69 m_sourceBus = AudioBus::create(numberOfChannels, 0, false);
70}
71
72void AudioResampler::process(AudioSourceProvider* provider, AudioBus* destinationBus, size_t framesToProcess)
73{
74 ASSERT(provider);
75 if (!provider)
76 return;
77
78 unsigned numberOfChannels = m_kernels.size();
79
80 // Make sure our configuration matches the bus we're rendering to.
81 bool channelsMatch = (destinationBus && destinationBus->numberOfChannels() == numberOfChannels);
82 ASSERT(channelsMatch);
83 if (!channelsMatch)
84 return;
85
86 // Setup the source bus.
87 for (unsigned i = 0; i < numberOfChannels; ++i) {
88 // Figure out how many frames we need to get from the provider, and a pointer to the buffer.
89 size_t framesNeeded;
90 float* fillPointer = m_kernels[i]->getSourcePointer(framesToProcess, &framesNeeded);
91 ASSERT(fillPointer);
92 if (!fillPointer)
93 return;
94
95 m_sourceBus->setChannelMemory(i, fillPointer, framesNeeded);
96 }
97
98 // Ask the provider to supply the desired number of source frames.
99 provider->provideInput(m_sourceBus.get(), m_sourceBus->length());
100
101 // Now that we have the source data, resample each channel into the destination bus.
102 // FIXME: optimize for the common stereo case where it's faster to process both left/right channels in the same inner loop.
103 for (unsigned i = 0; i < numberOfChannels; ++i) {
104 float* destination = destinationBus->channel(i)->mutableData();
105 m_kernels[i]->process(destination, framesToProcess);
106 }
107}
108
109void AudioResampler::setRate(double rate)
110{
111 if (std::isnan(rate) || std::isinf(rate) || rate <= 0.0)
112 return;
113
114 m_rate = std::min(AudioResampler::MaxRate, rate);
115}
116
117void AudioResampler::reset()
118{
119 unsigned numberOfChannels = m_kernels.size();
120 for (unsigned i = 0; i < numberOfChannels; ++i)
121 m_kernels[i]->reset();
122}
123
124} // namespace WebCore
125
126#endif // ENABLE(WEB_AUDIO)
127