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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

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  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY

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 #ifndef ReverbConvolver_h

 #define ReverbConvolver_h

 #include "ReverbAccumulationBuffer.h"

 #include "ReverbInputBuffer.h"

 #include "nsAutoPtr.h"

 #include "mozilla/MemoryReporting.h"

 #ifdef LOG

 #undef LOG

 #endif

 #include "base/condition_variable.h"

 #include "base/lock.h"

 #include "base/thread.h"

 namespace WebCore {

 class ReverbConvolverStage;

 class ReverbConvolver {

 public:

     // maxFFTSize can be adjusted (from say 2048 to 32768) depending on how much precision is necessary.

     // For certain tweaky de-convolving applications the phase errors add up quickly and lead to non-sensical results with

     // larger FFT sizes and single-precision floats.  In these cases 2048 is a good size.

     // If not doing multi-threaded convolution, then should not go > 8192.

     ReverbConvolver(const float* impulseResponseData, size_t impulseResponseLength, size_t renderSliceSize, size_t maxFFTSize, size_t convolverRenderPhase, bool useBackgroundThreads);

     ~ReverbConvolver();

     void process(const float* sourceChannelData, size_t sourceChannelLength,

                  float* destinationChannelData, size_t destinationChannelLength,

                  size_t framesToProcess);

     void reset();

     size_t impulseResponseLength() const { return m_impulseResponseLength; }

     ReverbInputBuffer* inputBuffer() { return &m_inputBuffer; }

     bool useBackgroundThreads() const { return m_useBackgroundThreads; }

     void backgroundThreadEntry();

     size_t latencyFrames() const;

     size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;

 private:

     nsTArray<nsAutoPtr<ReverbConvolverStage> > m_stages;

     nsTArray<nsAutoPtr<ReverbConvolverStage> > m_backgroundStages;

     size_t m_impulseResponseLength;

     ReverbAccumulationBuffer m_accumulationBuffer;

     // One or more background threads read from this input buffer which is fed from the realtime thread.

     ReverbInputBuffer m_inputBuffer;

     // First stage will be of size m_minFFTSize.  Each next stage will be twice as big until we hit m_maxFFTSize.

     size_t m_minFFTSize;

     size_t m_maxFFTSize;

     // But don't exceed this size in the real-time thread (if we're doing background processing).

     size_t m_maxRealtimeFFTSize;

     // Background thread and synchronization

     base::Thread m_backgroundThread;

     Lock m_backgroundThreadLock;

     ConditionVariable m_backgroundThreadCondition;

     bool m_useBackgroundThreads;

     bool m_wantsToExit;

     bool m_moreInputBuffered;

 };

 } // namespace WebCore

 #endif // ReverbConvolver_h