text: /*
   * Copyright (C) 2011, 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.
   *
   * THIS SOFTWARE IS PROVIDED BY APPLE INC. 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 INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
   * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
   * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include "config.h"
  
  #if ENABLE(WEB_AUDIO)
  
  #include "DynamicsCompressorNode.h"
  
  #include "AudioContext.h"
  #include "AudioNodeInput.h"
  #include "AudioNodeOutput.h"
  #include "DynamicsCompressor.h"
  
  // Set output to stereo by default.
  static const unsigned defaultNumberOfOutputChannels = 2;
  
  namespace WebCore {
  
  DynamicsCompressorNode::DynamicsCompressorNode(AudioContext* context, float sampleRate)
      : AudioNode(context, sampleRate)
  {
      addInput(adoptPtr(new AudioNodeInput(this)));
      addOutput(adoptPtr(new AudioNodeOutput(this, defaultNumberOfOutputChannels)));
  
      setNodeType(NodeTypeDynamicsCompressor);
  
      m_threshold = AudioParam::create(context, "threshold", -24, -100, 0);
      m_knee = AudioParam::create(context, "knee", 30, 0, 40);
      m_ratio = AudioParam::create(context, "ratio", 12, 1, 20);
      m_reduction = AudioParam::create(context, "reduction", 0, -20, 0);
      m_attack = AudioParam::create(context, "attack", 0.003, 0, 1);
      m_release = AudioParam::create(context, "release", 0.250, 0, 1);
  
      initialize();
  }
  
  DynamicsCompressorNode::~DynamicsCompressorNode()
  {
      uninitialize();
  }
  
  void DynamicsCompressorNode::process(size_t framesToProcess)
  {
      AudioBus* outputBus = output(0)->bus();
      ASSERT(outputBus);
  
      float threshold = m_threshold->value();
      float knee = m_knee->value();
      float ratio = m_ratio->value();
      float attack = m_attack->value();
      float release = m_release->value();
  
      m_dynamicsCompressor->setParameterValue(DynamicsCompressor::ParamThreshold, threshold);
      m_dynamicsCompressor->setParameterValue(DynamicsCompressor::ParamKnee, knee);
      m_dynamicsCompressor->setParameterValue(DynamicsCompressor::ParamRatio, ratio);
      m_dynamicsCompressor->setParameterValue(DynamicsCompressor::ParamAttack, attack);
      m_dynamicsCompressor->setParameterValue(DynamicsCompressor::ParamRelease, release);
  
      m_dynamicsCompressor->process(input(0)->bus(), outputBus, framesToProcess);
  
      float reduction = m_dynamicsCompressor->parameterValue(DynamicsCompressor::ParamReduction);
      m_reduction->setValue(reduction);
  }
  
  void DynamicsCompressorNode::reset()
  {
      m_dynamicsCompressor->reset();
  }
  
  void DynamicsCompressorNode::initialize()
  {
      if (isInitialized())
          return;
  
      AudioNode::initialize();    
      m_dynamicsCompressor = adoptPtr(new DynamicsCompressor(sampleRate(), defaultNumberOfOutputChannels));
  }
  
  void DynamicsCompressorNode::uninitialize()
  {
      if (!isInitialized())
          return;
  
      m_dynamicsCompressor.clear();
      AudioNode::uninitialize();
  }
  
  double DynamicsCompressorNode::tailTime() const
  {
      return m_dynamicsCompressor->tailTime();
  }
  
  double DynamicsCompressorNode::latencyTime() const
  {
      return m_dynamicsCompressor->latencyTime();
  }
  
  } // namespace WebCore
  
  #endif // ENABLE(WEB_AUDIO)
  