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 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
16 * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
17 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
18 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
19 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
20 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
22 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 */
24
25#pragma once
26
27#include "AudioDSPKernel.h"
28#include "Biquad.h"
29#include "BiquadProcessor.h"
30
31namespace WebCore {
32
33class BiquadProcessor;
34
35// BiquadDSPKernel is an AudioDSPKernel and is responsible for filtering one channel of a BiquadProcessor using a Biquad object.
36
37class BiquadDSPKernel final : public AudioDSPKernel {
38public:
39 explicit BiquadDSPKernel(BiquadProcessor* processor)
40 : AudioDSPKernel(processor)
41 {
42 }
43
44 // AudioDSPKernel
45 void process(const float* source, float* dest, size_t framesToProcess) override;
46 void reset() override { m_biquad.reset(); }
47
48 // Get the magnitude and phase response of the filter at the given
49 // set of frequencies (in Hz). The phase response is in radians.
50 void getFrequencyResponse(int nFrequencies,
51 const float* frequencyHz,
52 float* magResponse,
53 float* phaseResponse);
54
55 double tailTime() const override;
56 double latencyTime() const override;
57
58protected:
59 Biquad m_biquad;
60 BiquadProcessor* biquadProcessor() { return static_cast<BiquadProcessor*>(processor()); }
61
62 // To prevent audio glitches when parameters are changed,
63 // dezippering is used to slowly change the parameters.
64 // |useSmoothing| implies that we want to update using the
65 // smoothed values. Otherwise the final target values are
66 // used. If |forceUpdate| is true, we update the coefficients even
67 // if they are not dirty. (Used when computing the frequency
68 // response.)
69 void updateCoefficientsIfNecessary(bool useSmoothing, bool forceUpdate);
70};
71
72} // namespace WebCore
73