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#ifndef AudioResampler_h
26#define AudioResampler_h
27
28#include "AudioBus.h"
29#include "AudioResamplerKernel.h"
30#include "AudioSourceProvider.h"
31#include <memory>
32#include <wtf/Vector.h>
33
34namespace WebCore {
35
36// AudioResampler resamples the audio stream from an AudioSourceProvider.
37// The audio stream may be single or multi-channel.
38// The default constructor defaults to single-channel (mono).
39
40class AudioResampler {
41public:
42 AudioResampler();
43 AudioResampler(unsigned numberOfChannels);
44 ~AudioResampler() = default;
45
46 // Given an AudioSourceProvider, process() resamples the source stream into destinationBus.
47 void process(AudioSourceProvider*, AudioBus* destinationBus, size_t framesToProcess);
48
49 // Resets the processing state.
50 void reset();
51
52 void configureChannels(unsigned numberOfChannels);
53
54 // 0 < rate <= MaxRate
55 void setRate(double rate);
56 double rate() const { return m_rate; }
57
58 static const double MaxRate;
59
60private:
61 double m_rate;
62 Vector<std::unique_ptr<AudioResamplerKernel>> m_kernels;
63 RefPtr<AudioBus> m_sourceBus;
64};
65
66} // namespace WebCore
67
68#endif // AudioResampler_h
69