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

   1 /*
   2  * Copyright (C) 2010 Google Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  *
   8  * 1.  Redistributions of source code must retain the above copyright
   9  *     notice, this list of conditions and the following disclaimer.
  10  * 2.  Redistributions in binary form must reproduce the above copyright
  11  *     notice, this list of conditions and the following disclaimer in the
  12  *     documentation and/or other materials provided with the distribution.
  13  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
  14  *     its contributors may be used to endorse or promote products derived
  15  *     from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  20  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #ifndef ReverbConvolver_h
  30 #define ReverbConvolver_h
  31
  32 #include "platform/audio/AudioArray.h"
  33 #include "platform/audio/DirectConvolver.h"
  34 #include "platform/audio/FFTConvolver.h"
  35 #include "platform/audio/ReverbAccumulationBuffer.h"
  36 #include "platform/audio/ReverbConvolverStage.h"
  37 #include "platform/audio/ReverbInputBuffer.h"
  38 #include "wtf/OwnPtr.h"
  39 #include "wtf/RefCounted.h"
  40 #include "wtf/Vector.h"
  41
  42 namespace blink {
  43
  44 class AudioChannel;
  45 class WebThread;
  46
  47 class PLATFORM_EXPORT ReverbConvolver {
  48     WTF_MAKE_NONCOPYABLE(ReverbConvolver);
  49 public:
  50     // maxFFTSize can be adjusted (from say 2048 to 32768) depending on how much precision is necessary.
  51     // For certain tweaky de-convolving applications the phase errors add up quickly and lead to non-sensical results with
  52     // larger FFT sizes and single-precision floats.  In these cases 2048 is a good size.
  53     // If not doing multi-threaded convolution, then should not go > 8192.
  54     ReverbConvolver(AudioChannel* impulseResponse, size_t renderSliceSize, size_t maxFFTSize, size_t convolverRenderPhase, bool useBackgroundThreads);
  55     ~ReverbConvolver();
  56
  57     void process(const AudioChannel* sourceChannel, AudioChannel* destinationChannel, size_t framesToProcess);
  58     void reset();
  59
  60     ReverbInputBuffer* inputBuffer() { return &m_inputBuffer; }
  61
  62     size_t latencyFrames() const;
  63 private:
  64     void processInBackground();
  65
  66     Vector<OwnPtr<ReverbConvolverStage>> m_stages;
  67     Vector<OwnPtr<ReverbConvolverStage>> m_backgroundStages;
  68     size_t m_impulseResponseLength;
  69
  70     ReverbAccumulationBuffer m_accumulationBuffer;
  71
  72     // One or more background threads read from this input buffer which is fed from the realtime thread.
  73     ReverbInputBuffer m_inputBuffer;
  74
  75     // First stage will be of size m_minFFTSize.  Each next stage will be twice as big until we hit m_maxFFTSize.
  76     size_t m_minFFTSize;
  77     size_t m_maxFFTSize;
  78
  79     // But don't exceed this size in the real-time thread (if we're doing background processing).
  80     size_t m_maxRealtimeFFTSize;
  81
  82     // Background thread and synchronization
  83     OwnPtr<WebThread> m_backgroundThread;
  84 };
  85
  86 } // namespace blink
  87
  88 #endif // ReverbConvolver_h