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 are
6 * met:
7 *
8 *     * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *     * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 *     * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#ifndef AudioDSPKernel_h
32#define AudioDSPKernel_h
33
34#include "platform/audio/AudioDSPKernelProcessor.h"
35
36namespace blink {
37
38// AudioDSPKernel does the processing for one channel of an AudioDSPKernelProcessor.
39
40class PLATFORM_EXPORT AudioDSPKernel {
41public:
42    AudioDSPKernel(AudioDSPKernelProcessor* kernelProcessor)
43        : m_kernelProcessor(kernelProcessor)
44        , m_sampleRate(kernelProcessor->sampleRate())
45    {
46    }
47
48    AudioDSPKernel(float sampleRate)
49        : m_kernelProcessor(0)
50        , m_sampleRate(sampleRate)
51    {
52    }
53
54    virtual ~AudioDSPKernel();
55
56    // Subclasses must override process() to do the processing and reset() to reset DSP state.
57    virtual void process(const float* source, float* destination, size_t framesToProcess) = 0;
58    virtual void reset() = 0;
59
60    float sampleRate() const { return m_sampleRate; }
61    double nyquist() const { return 0.5 * sampleRate(); }
62
63    AudioDSPKernelProcessor* processor() { return m_kernelProcessor; }
64    const AudioDSPKernelProcessor* processor() const { return m_kernelProcessor; }
65
66    virtual double tailTime() const = 0;
67    virtual double latencyTime() const = 0;
68
69protected:
70    // Oilpan: This raw pointer is safe because the AudioDSPKernelProcessor
71    // object is guaranteed to be kept alive while the AudioDSPKernel object
72    // is alive. Ideally we want to move the AudioDSPKernel hierarchy to
73    // the heap and use a Member<AudioDSPKernelProcessor>. However, we cannot
74    // do that because AudioDSPKernel can be allocated in audio threads
75    // (which are not registered to Oilpan).
76    GC_PLUGIN_IGNORE("http://crbug.com/404578")
77    AudioDSPKernelProcessor* m_kernelProcessor;
78    float m_sampleRate;
79};
80
81} // namespace blink
82
83#endif // AudioDSPKernel_h
84