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diff --git a/WebCore/platform/audio/ReverbConvolverStage.h b/WebCore/platform/audio/ReverbConvolverStage.h
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+/*
+ * 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
+ * (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 ReverbConvolverStage_h
+#define ReverbConvolverStage_h
+
+#include "AudioFloatArray.h"
+#include "FFTFrame.h"
+#include <wtf/OwnPtr.h>
+
+namespace WebCore {
+
+class ReverbAccumulationBuffer;
+class ReverbConvolver;
+class FFTConvolver;
+    
+// A ReverbConvolverStage represents the convolution associated with a sub-section of a large impulse response.
+// It incorporates a delay line to account for the offset of the sub-section within the larger impulse response.
+class ReverbConvolverStage {
+public:
+    // renderPhase is useful to know so that we can manipulate the pre versus post delay so that stages will perform
+    // their heavy work (FFT processing) on different slices to balance the load in a real-time thread.
+    ReverbConvolverStage(float* impulseResponse, size_t responseLength, size_t reverbTotalLatency, size_t stageOffset, size_t stageLength,
+                         size_t fftSize, size_t renderPhase, size_t renderSliceSize, ReverbAccumulationBuffer* accumulationBuffer);
+
+    // WARNING: framesToProcess must be such that it evenly divides the delay buffer size (stage_offset).
+    void process(float* source, size_t framesToProcess);
+
+    void processInBackground(ReverbConvolver* convolver, size_t framesToProcess);
+
+    void reset();
+
+    // Useful for background processing
+    int inputReadIndex() const { return m_inputReadIndex; }
+
+private:
+    FFTFrame m_fftKernel;
+    OwnPtr<FFTConvolver> m_convolver;
+
+    AudioFloatArray m_preDelayBuffer;
+
+    ReverbAccumulationBuffer* m_accumulationBuffer;
+    int m_accumulationReadIndex;
+    int m_inputReadIndex;
+
+    size_t m_preDelayLength;
+    size_t m_postDelayLength;
+    size_t m_preReadWriteIndex;
+    size_t m_framesProcessed;
+
+    AudioFloatArray m_temporaryBuffer;
+
+    size_t m_impulseResponseLength;
+};
+
+} // namespace WebCore
+
+#endif // ReverbConvolverStage_h