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      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 are
      6  * met:
      7  *
      8  *     * Redistributions of source code must retain the above copyright
      9  * notice, this list of conditions and the following disclaimer.
     10  *     * Redistributions in binary form must reproduce the above
     11  * copyright notice, this list of conditions and the following disclaimer
     12  * in the documentation and/or other materials provided with the
     13  * distribution.
     14  *     * Neither the name of Google Inc. nor the names of its
     15  * contributors may be used to endorse or promote products derived from
     16  * this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 
     31 #ifndef AudioDSPKernelProcessor_h
     32 #define AudioDSPKernelProcessor_h
     33 
     34 #include "AudioBus.h"
     35 #include "AudioProcessor.h"
     36 #include <wtf/OwnPtr.h>
     37 #include <wtf/PassOwnPtr.h>
     38 #include <wtf/Vector.h>
     39 
     40 namespace WebCore {
     41 
     42 class AudioBus;
     43 class AudioDSPKernel;
     44 class AudioProcessor;
     45 
     46 // AudioDSPKernelProcessor processes one input -> one output (N channels each)
     47 // It uses one AudioDSPKernel object per channel to do the processing, thus there is no cross-channel processing.
     48 // Despite this limitation it turns out to be a very common and useful type of processor.
     49 
     50 class AudioDSPKernelProcessor : public AudioProcessor {
     51 public:
     52     // numberOfChannels may be later changed if object is not yet in an "initialized" state
     53     AudioDSPKernelProcessor(double sampleRate, unsigned numberOfChannels);
     54 
     55     // Subclasses create the appropriate type of processing kernel here.
     56     // We'll call this to create a kernel for each channel.
     57     virtual PassOwnPtr<AudioDSPKernel> createKernel() = 0;
     58 
     59     // AudioProcessor methods
     60     virtual void initialize();
     61     virtual void uninitialize();
     62     virtual void process(AudioBus* source, AudioBus* destination, size_t framesToProcess);
     63     virtual void reset();
     64     virtual void setNumberOfChannels(unsigned numberOfChannels);
     65 
     66     unsigned numberOfChannels() const { return m_numberOfChannels; }
     67 
     68 protected:
     69     unsigned m_numberOfChannels;
     70     Vector<OwnPtr<AudioDSPKernel> > m_kernels;
     71     bool m_hasJustReset;
     72 };
     73 
     74 } // namespace WebCore
     75 
     76 #endif // AudioDSPKernelProcessor_h
     77