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 Reverb_h
30#define Reverb_h
31
32#include "ReverbConvolver.h"
33#include <wtf/Vector.h>
34
35namespace WebCore {
36
37class AudioBus;
38
39// Multi-channel convolution reverb with channel matrixing - one or more ReverbConvolver objects are used internally.
40
41class Reverb {
42public:
43    enum { MaxFrameSize = 256 };
44
45    // renderSliceSize is a rendering hint, so the FFTs can be optimized to not all occur at the same time (very bad when rendering on a real-time thread).
46    Reverb(AudioBus* impulseResponseBuffer, size_t renderSliceSize, size_t maxFFTSize, size_t numberOfChannels, bool useBackgroundThreads);
47
48    void process(AudioBus* sourceBus, AudioBus* destinationBus, size_t framesToProcess);
49    void reset();
50
51    unsigned impulseResponseLength() const { return m_impulseResponseLength; }
52
53private:
54    void initialize(AudioBus* impulseResponseBuffer, size_t renderSliceSize, size_t maxFFTSize, size_t numberOfChannels, bool useBackgroundThreads);
55
56    size_t m_impulseResponseLength;
57
58    Vector<OwnPtr<ReverbConvolver> > m_convolvers;
59
60    // For "True" stereo processing
61    OwnPtr<AudioBus> m_tempBuffer;
62};
63
64} // namespace WebCore
65
66#endif // Reverb_h
67