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 ReverbConvolver_h
30#define ReverbConvolver_h
31
32#include "AudioArray.h"
33#include "FFTConvolver.h"
34#include "ReverbAccumulationBuffer.h"
35#include "ReverbConvolverStage.h"
36#include "ReverbInputBuffer.h"
37#include <wtf/OwnPtr.h>
38#include <wtf/RefCounted.h>
39#include <wtf/Threading.h>
40#include <wtf/Vector.h>
41
42namespace WebCore {
43
44class AudioChannel;
45
46class ReverbConvolver {
47public:
48    // maxFFTSize can be adjusted (from say 2048 to 32768) depending on how much precision is necessary.
49    // For certain tweaky de-convolving applications the phase errors add up quickly and lead to non-sensical results with
50    // larger FFT sizes and single-precision floats.  In these cases 2048 is a good size.
51    // If not doing multi-threaded convolution, then should not go > 8192.
52    ReverbConvolver(AudioChannel* impulseResponse, size_t renderSliceSize, size_t maxFFTSize, size_t convolverRenderPhase, bool useBackgroundThreads);
53    ~ReverbConvolver();
54
55    void process(AudioChannel* sourceChannel, AudioChannel* destinationChannel, size_t framesToProcess);
56    void reset();
57
58    size_t impulseResponseLength() const { return m_impulseResponseLength; }
59
60    ReverbInputBuffer* inputBuffer() { return &m_inputBuffer; }
61
62    bool useBackgroundThreads() const { return m_useBackgroundThreads; }
63    void backgroundThreadEntry();
64
65private:
66    Vector<OwnPtr<ReverbConvolverStage> > m_stages;
67    Vector<OwnPtr<ReverbConvolverStage> > m_backgroundStages;
68    size_t m_impulseResponseLength;
69
70    ReverbAccumulationBuffer m_accumulationBuffer;
71
72    // One or more background threads read from this input buffer which is fed from the realtime thread.
73    ReverbInputBuffer m_inputBuffer;
74
75    // We're given a rendering hint, so the FFTs can be optimized to not all occur at the same time
76    // (very bad when rendering on a real-time thread).
77    size_t m_renderSliceSize;
78
79    // First stage will be of size m_minFFTSize.  Each next stage will be twice as big until we hit m_maxFFTSize.
80    size_t m_minFFTSize;
81    size_t m_maxFFTSize;
82
83    // But don't exceed this size in the real-time thread (if we're doing background processing).
84    size_t m_maxRealtimeFFTSize;
85
86    // Background thread and synchronization
87    bool m_useBackgroundThreads;
88    ThreadIdentifier m_backgroundThread;
89    bool m_wantsToExit;
90    bool m_moreInputBuffered;
91    mutable Mutex m_backgroundThreadLock;
92    mutable ThreadCondition m_backgroundThreadCondition;
93};
94
95} // namespace WebCore
96
97#endif // ReverbConvolver_h
98