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 ReverbConvolverStage_h
30 #define ReverbConvolverStage_h
31 
32 #include "FFTConvolver.h"
33 
34 #include "nsTArray.h"
35 #include "mozilla/FFTBlock.h"
36 #include "mozilla/MemoryReporting.h"
37 #include "mozilla/UniquePtr.h"
38 
39 namespace WebCore {
40 
41 using mozilla::FFTBlock;
42 
43 class ReverbAccumulationBuffer;
44 class ReverbConvolver;
45 
46 // A ReverbConvolverStage represents the convolution associated with a
47 // sub-section of a large impulse response. It incorporates a delay line to
48 // account for the offset of the sub-section within the larger impulse response.
49 class ReverbConvolverStage {
50  public:
51   // renderPhase is useful to know so that we can manipulate the pre versus post
52   // delay so that stages will perform their heavy work (FFT processing) on
53   // different slices to balance the load in a real-time thread.
54   ReverbConvolverStage(const float* impulseResponse, size_t responseLength,
55                        size_t reverbTotalLatency, size_t stageOffset,
56                        size_t stageLength, size_t fftSize, size_t renderPhase,
57                        ReverbAccumulationBuffer*);
58 
59   // |source| must point to an array of WEBAUDIO_BLOCK_SIZE elements.
60   void process(const float* source);
61 
62   void processInBackground(ReverbConvolver* convolver);
63 
64   // Useful for background processing
inputReadIndex()65   int inputReadIndex() const { return m_inputReadIndex; }
66 
67   size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
68 
69  private:
70   mozilla::UniquePtr<FFTBlock> m_fftKernel;
71   mozilla::UniquePtr<FFTConvolver> m_fftConvolver;
72 
73   ReverbAccumulationBuffer* m_accumulationBuffer;
74   size_t m_accumulationReadIndex;
75   int m_inputReadIndex;
76 
77   size_t m_postDelayLength;
78 
79   nsTArray<float> m_temporaryBuffer;
80 };
81 
82 }  // namespace WebCore
83 
84 #endif  // ReverbConvolverStage_h
85