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 "platform/audio/AudioArray.h"
33#include "platform/audio/FFTFrame.h"
34#include "wtf/Noncopyable.h"
35#include "wtf/OwnPtr.h"
36
37namespace blink {
38
39class ReverbAccumulationBuffer;
40class ReverbConvolver;
41class FFTConvolver;
42class DirectConvolver;
43
44// A ReverbConvolverStage represents the convolution associated with a sub-section of a large impulse response.
45// It incorporates a delay line to account for the offset of the sub-section within the larger impulse response.
46class PLATFORM_EXPORT ReverbConvolverStage {
47    WTF_MAKE_NONCOPYABLE(ReverbConvolverStage);
48public:
49    // renderPhase is useful to know so that we can manipulate the pre versus post delay so that stages will perform
50    // their heavy work (FFT processing) on different slices to balance the load in a real-time thread.
51    ReverbConvolverStage(const float* impulseResponse, size_t responseLength, size_t reverbTotalLatency, size_t stageOffset, size_t stageLength, size_t fftSize, size_t renderPhase, size_t renderSliceSize, ReverbAccumulationBuffer*, bool directMode = false);
52
53    // WARNING: framesToProcess must be such that it evenly divides the delay buffer size (stage_offset).
54    void process(const float* source, size_t framesToProcess);
55
56    void processInBackground(ReverbConvolver* convolver, size_t framesToProcess);
57
58    void reset();
59
60    // Useful for background processing
61    int inputReadIndex() const { return m_inputReadIndex; }
62
63private:
64    OwnPtr<FFTFrame> m_fftKernel;
65    OwnPtr<FFTConvolver> m_fftConvolver;
66
67    AudioFloatArray m_preDelayBuffer;
68
69    ReverbAccumulationBuffer* m_accumulationBuffer;
70    int m_accumulationReadIndex;
71    int m_inputReadIndex;
72
73    size_t m_preDelayLength;
74    size_t m_postDelayLength;
75    size_t m_preReadWriteIndex;
76    size_t m_framesProcessed;
77
78    AudioFloatArray m_temporaryBuffer;
79
80    bool m_directMode;
81    OwnPtr<AudioFloatArray> m_directKernel;
82    OwnPtr<DirectConvolver> m_directConvolver;
83};
84
85} // namespace blink
86
87#endif // ReverbConvolverStage_h
88