Source/WebCore/platform/audio/MultiChannelResampler.h

/*
 * Copyright (C) 2011 Google Inc. All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
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 * 2.  Redistributions in binary form must reproduce the above copyright
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 *     its contributors may be used to endorse or promote products derived
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 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
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#ifndef MultiChannelResampler_h
#define MultiChannelResampler_h

#include "SincResampler.h"
#include <memory>
#include <wtf/Vector.h>

namespace WebCore {

class AudioBus;

class MultiChannelResampler final {
    WTF_MAKE_FAST_ALLOCATED;
public:   
    explicit MultiChannelResampler(double scaleFactor, unsigned numberOfChannels);
    ~MultiChannelResampler();

    // Process given AudioSourceProvider for streaming applications.
    void process(AudioSourceProvider*, AudioBus* destination, size_t framesToProcess);

private:
    // FIXME: the mac port can have a more highly optimized implementation based on CoreAudio
    // instead of SincResampler. For now the default implementation will be used on all ports.
    // https://bugs.webkit.org/show_bug.cgi?id=75118
    
    // Each channel will be resampled using a high-quality SincResampler.
    Vector<std::unique_ptr<SincResampler>> m_kernels;
    
    unsigned m_numberOfChannels;

    class ChannelProvider;
    std::unique_ptr<ChannelProvider> m_channelProvider;
};

} // namespace WebCore

#endif // MultiChannelResampler_h