third_party/WebKit/Source/platform/audio/AudioProcessor.h

/*
 * Copyright (C) 2010 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 are
 * met:
 *
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 * notice, this list of conditions and the following disclaimer.
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 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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 */

#ifndef AudioProcessor_h
#define AudioProcessor_h

#include "platform/PlatformExport.h"
#include "wtf/Allocator.h"

namespace blink {

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 PLATFORM_EXPORT AudioProcessor {
  USING_FAST_MALLOC(AudioProcessor);

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

  virtual ~AudioProcessor();

  // 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;

  // 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;

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

}  // namespace blink

#endif  // AudioProcessor_h