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#include "config.h"
26
27#if ENABLE(WEB_AUDIO)
28
29#include "BiquadDSPKernel.h"
30
31#include "BiquadProcessor.h"
32
33namespace WebCore {
34
35void BiquadDSPKernel::process(const float* source, float* destination, size_t framesToProcess)
36{
37    ASSERT(source && destination && biquadProcessor());
38
39    // Recompute filter coefficients if any of the parameters have changed.
40    // FIXME: as an optimization, implement a way that a Biquad object can simply copy its internal filter coefficients from another Biquad object.
41    // Then re-factor this code to only run for the first BiquadDSPKernel of each BiquadProcessor.
42    if (biquadProcessor()->filterCoefficientsDirty()) {
43        double value1 = biquadProcessor()->parameter1()->smoothedValue();
44        double value2 = biquadProcessor()->parameter2()->smoothedValue();
45
46        // Convert from Hertz to normalized frequency 0 -> 1.
47        double nyquist = this->nyquist();
48        double normalizedValue1 = value1 / nyquist;
49
50        // Configure the biquad with the new filter parameters for the appropriate type of filter.
51        switch (biquadProcessor()->type()) {
52        case BiquadProcessor::LowPass2:
53            m_biquad.setLowpassParams(normalizedValue1, value2);
54            break;
55
56        case BiquadProcessor::HighPass2:
57            m_biquad.setHighpassParams(normalizedValue1, value2);
58            break;
59
60        case BiquadProcessor::LowShelf:
61            m_biquad.setLowShelfParams(normalizedValue1, value2);
62            break;
63
64        // FIXME: add other biquad filter types...
65        case BiquadProcessor::Peaking:
66        case BiquadProcessor::Allpass:
67        case BiquadProcessor::HighShelf:
68            break;
69        }
70    }
71
72    m_biquad.process(source, destination, framesToProcess);
73}
74
75} // namespace WebCore
76
77#endif // ENABLE(WEB_AUDIO)
78