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#ifndef RealtimeAnalyser_h 26#define RealtimeAnalyser_h 27 28#include "AudioArray.h" 29#include <memory> 30#include <runtime/Float32Array.h> 31#include <runtime/Uint8Array.h> 32#include <wtf/Forward.h> 33#include <wtf/Noncopyable.h> 34 35namespace WebCore { 36 37class AudioBus; 38class FFTFrame; 39 40class RealtimeAnalyser { 41 WTF_MAKE_NONCOPYABLE(RealtimeAnalyser); 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 100 101#endif // RealtimeAnalyser_h 102