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

/*
 * Copyright (C) 2010 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 * 2.  Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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 */

#ifndef AudioDestination_h
#define AudioDestination_h

#include "platform/audio/AudioBus.h"
#include "platform/audio/AudioIOCallback.h"
#include "platform/audio/AudioSourceProvider.h"
#include "public/platform/WebAudioDevice.h"
#include "public/platform/WebVector.h"
#include "wtf/Allocator.h"
#include "wtf/Noncopyable.h"
#include "wtf/PassRefPtr.h"
#include "wtf/text/WTFString.h"
#include <memory>

namespace blink {

class AudioFIFO;
class AudioPullFIFO;
class SecurityOrigin;

// An AudioDestination using Chromium's audio system

class PLATFORM_EXPORT AudioDestination : public WebAudioDevice::RenderCallback,
                                         public AudioSourceProvider {
  USING_FAST_MALLOC(AudioDestination);
  WTF_MAKE_NONCOPYABLE(AudioDestination);

 public:
  AudioDestination(AudioIOCallback&,
                   const String& inputDeviceId,
                   unsigned numberOfInputChannels,
                   unsigned numberOfOutputChannels,
                   float sampleRate,
                   PassRefPtr<SecurityOrigin>);
  ~AudioDestination() override;

  // Pass in (numberOfInputChannels > 0) if live/local audio input is desired.
  // Port-specific device identification information for live/local input
  // streams can be passed in the inputDeviceId.
  static std::unique_ptr<AudioDestination> create(
      AudioIOCallback&,
      const String& inputDeviceId,
      unsigned numberOfInputChannels,
      unsigned numberOfOutputChannels,
      float sampleRate,
      PassRefPtr<SecurityOrigin>);

  virtual void start();
  virtual void stop();
  bool isPlaying() { return m_isPlaying; }

  float sampleRate() const { return m_sampleRate; }

  // WebAudioDevice::RenderCallback
  void render(const WebVector<float*>& sourceData,
              const WebVector<float*>& audioData,
              size_t numberOfFrames) override;

  // AudioSourceProvider
  void provideInput(AudioBus*, size_t framesToProcess) override;

  static float hardwareSampleRate();

  // maxChannelCount() returns the total number of output channels of the audio
  // hardware.  A value of 0 indicates that the number of channels cannot be
  // configured and that only stereo (2-channel) destinations can be created.
  // The numberOfOutputChannels parameter of AudioDestination::create() is
  // allowed to be a value: 1 <= numberOfOutputChannels <= maxChannelCount(),
  // or if maxChannelCount() equals 0, then numberOfOutputChannels must be 2.
  static unsigned long maxChannelCount();

 private:
  AudioIOCallback& m_callback;
  unsigned m_numberOfOutputChannels;
  RefPtr<AudioBus> m_inputBus;
  RefPtr<AudioBus> m_renderBus;
  float m_sampleRate;
  bool m_isPlaying;
  std::unique_ptr<WebAudioDevice> m_audioDevice;
  size_t m_callbackBufferSize;

  std::unique_ptr<AudioFIFO> m_inputFifo;
  std::unique_ptr<AudioPullFIFO> m_fifo;
};

}  // namespace blink

#endif  // AudioDestination_h