1/*
2 * Copyright (C) 2010 Google Inc. All rights reserved.
3 * Copyright (C) 2015 Apple Inc. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of Apple Inc. ("Apple") nor the names of
15 * its contributors may be used to endorse or promote products derived
16 * from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
19 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
20 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
21 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
22 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30#ifndef ReverbConvolver_h
31#define ReverbConvolver_h
32
33#include "ReverbAccumulationBuffer.h"
34#include "ReverbConvolverStage.h"
35#include "ReverbInputBuffer.h"
36#include <memory>
37#include <wtf/Condition.h>
38#include <wtf/Lock.h>
39#include <wtf/Threading.h>
40#include <wtf/Vector.h>
41
42namespace WebCore {
43
44class AudioChannel;
45
46class ReverbConvolver {
47 WTF_MAKE_FAST_ALLOCATED;
48public:
49 // maxFFTSize can be adjusted (from say 2048 to 32768) depending on how much precision is necessary.
50 // For certain tweaky de-convolving applications the phase errors add up quickly and lead to non-sensical results with
51 // larger FFT sizes and single-precision floats. In these cases 2048 is a good size.
52 // If not doing multi-threaded convolution, then should not go > 8192.
53 ReverbConvolver(AudioChannel* impulseResponse, size_t renderSliceSize, size_t maxFFTSize, size_t convolverRenderPhase, bool useBackgroundThreads);
54 ~ReverbConvolver();
55
56 void process(const AudioChannel* sourceChannel, AudioChannel* destinationChannel, size_t framesToProcess);
57 void reset();
58
59 size_t impulseResponseLength() const { return m_impulseResponseLength; }
60
61 ReverbInputBuffer* inputBuffer() { return &m_inputBuffer; }
62
63 bool useBackgroundThreads() const { return m_useBackgroundThreads; }
64
65 size_t latencyFrames() const;
66private:
67 void backgroundThreadEntry();
68
69 Vector<std::unique_ptr<ReverbConvolverStage>> m_stages;
70 Vector<std::unique_ptr<ReverbConvolverStage>> m_backgroundStages;
71 size_t m_impulseResponseLength;
72
73 ReverbAccumulationBuffer m_accumulationBuffer;
74
75 // One or more background threads read from this input buffer which is fed from the realtime thread.
76 ReverbInputBuffer m_inputBuffer;
77
78 // First stage will be of size m_minFFTSize. Each next stage will be twice as big until we hit m_maxFFTSize.
79 size_t m_minFFTSize;
80 size_t m_maxFFTSize;
81
82 // But don't exceed this size in the real-time thread (if we're doing background processing).
83 size_t m_maxRealtimeFFTSize;
84
85 // Background thread and synchronization
86 bool m_useBackgroundThreads;
87 RefPtr<Thread> m_backgroundThread;
88 bool m_wantsToExit { false };
89 bool m_moreInputBuffered { false };
90 mutable Lock m_backgroundThreadMutex;
91 mutable Condition m_backgroundThreadConditionVariable;
92};
93
94} // namespace WebCore
95
96#endif // ReverbConvolver_h
97