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