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diff --git a/dom/media/webaudio/blink/DynamicsCompressor.h b/dom/media/webaudio/blink/DynamicsCompressor.h
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+/*
+ * 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.
+ * 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
+ * (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.
+ */
+
+#ifndef DynamicsCompressor_h
+#define DynamicsCompressor_h
+
+#include "DynamicsCompressorKernel.h"
+#include "ZeroPole.h"
+
+#include "nsTArray.h"
+#include "mozilla/MemoryReporting.h"
+#include "mozilla/UniquePtr.h"
+
+namespace mozilla {
+class AudioBlock;
+}  // namespace mozilla
+
+namespace WebCore {
+
+using mozilla::AudioBlock;
+using mozilla::UniquePtr;
+
+// DynamicsCompressor implements a flexible audio dynamics compression effect
+// such as is commonly used in musical production and game audio. It lowers the
+// volume of the loudest parts of the signal and raises the volume of the
+// softest parts, making the sound richer, fuller, and more controlled.
+
+class DynamicsCompressor {
+ public:
+  enum {
+    ParamThreshold,
+    ParamKnee,
+    ParamRatio,
+    ParamAttack,
+    ParamRelease,
+    ParamPreDelay,
+    ParamReleaseZone1,
+    ParamReleaseZone2,
+    ParamReleaseZone3,
+    ParamReleaseZone4,
+    ParamPostGain,
+    ParamFilterStageGain,
+    ParamFilterStageRatio,
+    ParamFilterAnchor,
+    ParamEffectBlend,
+    ParamReduction,
+    ParamLast
+  };
+
+  DynamicsCompressor(float sampleRate, unsigned numberOfChannels);
+
+  void process(const AudioBlock* sourceChunk, AudioBlock* destinationChunk,
+               unsigned framesToProcess);
+  void reset();
+  void setNumberOfChannels(unsigned);
+  unsigned numberOfChannels() const { return m_numberOfChannels; }
+
+  void setParameterValue(unsigned parameterID, float value);
+  float parameterValue(unsigned parameterID);
+
+  float sampleRate() const { return m_sampleRate; }
+  float nyquist() const { return m_sampleRate / 2; }
+
+  double tailTime() const { return 0; }
+  double latencyTime() const {
+    return m_compressor.latencyFrames() / static_cast<double>(sampleRate());
+  }
+
+  size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
+
+ protected:
+  unsigned m_numberOfChannels;
+
+  // m_parameters holds the tweakable compressor parameters.
+  float m_parameters[ParamLast];
+  void initializeParameters();
+
+  float m_sampleRate;
+
+  // Emphasis filter controls.
+  float m_lastFilterStageRatio;
+  float m_lastAnchor;
+  float m_lastFilterStageGain;
+
+  struct ZeroPoleFilterPack4 {
+    ZeroPole filters[4];
+    size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const {
+      return aMallocSizeOf(this);
+    }
+  };
+
+  // Per-channel emphasis filters.
+  nsTArray<UniquePtr<ZeroPoleFilterPack4> > m_preFilterPacks;
+  nsTArray<UniquePtr<ZeroPoleFilterPack4> > m_postFilterPacks;
+
+  mozilla::UniquePtr<const float*[]> m_sourceChannels;
+  mozilla::UniquePtr<float*[]> m_destinationChannels;
+
+  void setEmphasisStageParameters(unsigned stageIndex, float gain,
+                                  float normalizedFrequency /* 0 -> 1 */);
+  void setEmphasisParameters(float gain, float anchorFreq,
+                             float filterStageRatio);
+
+  // The core compressor.
+  DynamicsCompressorKernel m_compressor;
+};
+
+}  // namespace WebCore
+
+#endif  // DynamicsCompressor_h