1/*
2 * Copyright (C) 2011, 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 "AudioArray.h"
28#include "AudioDSPKernel.h"
29#include "DownSampler.h"
30#include "UpSampler.h"
31#include "WaveShaperProcessor.h"
32#include <memory>
33
34namespace WebCore {
35
36// WaveShaperDSPKernel is an AudioDSPKernel and is responsible for non-linear distortion on one channel.
37
38class WaveShaperDSPKernel final : public AudioDSPKernel {
39public:
40 explicit WaveShaperDSPKernel(WaveShaperProcessor*);
41
42 // AudioDSPKernel
43 void process(const float* source, float* dest, size_t framesToProcess) override;
44 void reset() override;
45 double tailTime() const override { return 0; }
46 double latencyTime() const override;
47
48 // Oversampling requires more resources, so let's only allocate them if needed.
49 void lazyInitializeOversampling();
50
51protected:
52 // Apply the shaping curve.
53 void processCurve(const float* source, float* dest, size_t framesToProcess);
54
55 // Use up-sampling, process at the higher sample-rate, then down-sample.
56 void processCurve2x(const float* source, float* dest, size_t framesToProcess);
57 void processCurve4x(const float* source, float* dest, size_t framesToProcess);
58
59 WaveShaperProcessor* waveShaperProcessor() { return static_cast<WaveShaperProcessor*>(processor()); }
60
61 // Oversampling.
62 std::unique_ptr<AudioFloatArray> m_tempBuffer;
63 std::unique_ptr<AudioFloatArray> m_tempBuffer2;
64 std::unique_ptr<UpSampler> m_upSampler;
65 std::unique_ptr<DownSampler> m_downSampler;
66 std::unique_ptr<UpSampler> m_upSampler2;
67 std::unique_ptr<DownSampler> m_downSampler2;
68};
69
70} // namespace WebCore
71