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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
      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 ReverbInputBuffer_h
     30 #define ReverbInputBuffer_h
     31 
     32 #include "AudioArray.h"
     33 
     34 namespace WebCore {
     35 
     36 // ReverbInputBuffer is used to buffer input samples for deferred processing by the background threads.
     37 class ReverbInputBuffer {
     38 public:
     39     ReverbInputBuffer(size_t length);
     40 
     41     // The realtime audio thread keeps writing samples here.
     42     // The assumption is that the buffer's length is evenly divisible by numberOfFrames (for nearly all cases this will be fine).
     43     // FIXME: remove numberOfFrames restriction...
     44     void write(float* sourceP, size_t numberOfFrames);
     45 
     46     // Background threads can call this to check if there's anything to read...
     47     size_t writeIndex() const { return m_writeIndex; }
     48 
     49     // The individual background threads read here (and hope that they can keep up with the buffer writing).
     50     // readIndex is updated with the next readIndex to read from...
     51     // The assumption is that the buffer's length is evenly divisible by numberOfFrames.
     52     // FIXME: remove numberOfFrames restriction...
     53     float* directReadFrom(int* readIndex, size_t numberOfFrames);
     54 
     55     void reset();
     56 
     57 private:
     58     AudioFloatArray m_buffer;
     59     size_t m_writeIndex;
     60 };
     61 
     62 } // namespace WebCore
     63 
     64 #endif // ReverbInputBuffer_h
     65