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 "AudioArray.h"
28#include "FFTFrame.h"
29#include <JavaScriptCore/Float32Array.h>
30#include <JavaScriptCore/Uint8Array.h>
31#include <memory>
32#include <wtf/Forward.h>
33#include <wtf/Noncopyable.h>
34
35namespace WebCore {
36
37class AudioBus;
38
39class RealtimeAnalyser {
40 WTF_MAKE_NONCOPYABLE(RealtimeAnalyser);
41 WTF_MAKE_FAST_ALLOCATED;
42public:
43 RealtimeAnalyser();
44 virtual ~RealtimeAnalyser();
45
46 void reset();
47
48 size_t fftSize() const { return m_fftSize; }
49 bool setFftSize(size_t);
50
51 unsigned frequencyBinCount() const { return m_fftSize / 2; }
52
53 void setMinDecibels(double k) { m_minDecibels = k; }
54 double minDecibels() const { return m_minDecibels; }
55
56 void setMaxDecibels(double k) { m_maxDecibels = k; }
57 double maxDecibels() const { return m_maxDecibels; }
58
59 void setSmoothingTimeConstant(double k) { m_smoothingTimeConstant = k; }
60 double smoothingTimeConstant() const { return m_smoothingTimeConstant; }
61
62 void getFloatFrequencyData(JSC::Float32Array*);
63 void getByteFrequencyData(JSC::Uint8Array*);
64 void getByteTimeDomainData(JSC::Uint8Array*);
65
66 // The audio thread writes input data here.
67 void writeInput(AudioBus*, size_t framesToProcess);
68
69 static const double DefaultSmoothingTimeConstant;
70 static const double DefaultMinDecibels;
71 static const double DefaultMaxDecibels;
72
73 static const unsigned DefaultFFTSize;
74 static const unsigned MinFFTSize;
75 static const unsigned MaxFFTSize;
76 static const unsigned InputBufferSize;
77
78private:
79 // The audio thread writes the input audio here.
80 AudioFloatArray m_inputBuffer;
81 unsigned m_writeIndex;
82
83 size_t m_fftSize;
84 std::unique_ptr<FFTFrame> m_analysisFrame;
85 void doFFTAnalysis();
86
87 // doFFTAnalysis() stores the floating-point magnitude analysis data here.
88 AudioFloatArray m_magnitudeBuffer;
89 AudioFloatArray& magnitudeBuffer() { return m_magnitudeBuffer; }
90
91 // A value between 0 and 1 which averages the previous version of m_magnitudeBuffer with the current analysis magnitude data.
92 double m_smoothingTimeConstant;
93
94 // The range used when converting when using getByteFrequencyData().
95 double m_minDecibels;
96 double m_maxDecibels;
97};
98
99} // namespace WebCore
100