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 * Copyright (C) 2010 Google Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions are
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 *
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 * notice, this list of conditions and the following disclaimer.
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 * in the documentation and/or other materials provided with the
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 * this software without specific prior written permission.
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#ifndef AudioProcessor_h
#define AudioProcessor_h

namespace WebCore {

class AudioBus;

// AudioProcessor is an abstract base class representing an audio signal processing object with a single input and a single output,
// where the number of input channels equals the number of output channels.  It can be used as one part of a complex DSP algorithm,
// or as the processor for a basic (one input - one output) AudioNode.

class AudioProcessor {
    WTF_MAKE_NONCOPYABLE(AudioProcessor);
    WTF_MAKE_FAST_ALLOCATED;
public:
    AudioProcessor(float sampleRate, unsigned numberOfChannels)
        : m_initialized(false)
        , m_numberOfChannels(numberOfChannels)
        , m_sampleRate(sampleRate)
    {
    }

    virtual ~AudioProcessor() = default;

    // Full initialization can be done here instead of in the constructor.
    virtual void initialize() = 0;
    virtual void uninitialize() = 0;

    // Processes the source to destination bus.  The number of channels must match in source and destination.
    virtual void process(const AudioBus* source, AudioBus* destination, size_t framesToProcess) = 0;

    // Forces all AudioParams in the processor to run the timeline, bypassing any other processing the processor
    // would do in process().
    virtual void processOnlyAudioParams(size_t) { }

    // Resets filter state
    virtual void reset() = 0;

    virtual void setNumberOfChannels(unsigned) = 0;
    virtual unsigned numberOfChannels() const = 0;

    bool isInitialized() const { return m_initialized; }

    float sampleRate() const { return m_sampleRate; }

    virtual double tailTime() const = 0;
    virtual double latencyTime() const = 0;
    virtual bool requiresTailProcessing() const = 0;

protected:
    bool m_initialized;
    unsigned m_numberOfChannels;
    float m_sampleRate;
};

} // namespace WebCore

#endif // AudioProcessor_h