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 <wtf/Noncopyable.h> 30 #include <wtf/OwnPtr.h> 31 32 namespace WebCore { 33 34 class AudioBus; 35 class FFTFrame; 36 37 #if ENABLE(WEBGL) 38 class Float32Array; 39 class Uint8Array; 40 #endif 41 42 class RealtimeAnalyser { 43 WTF_MAKE_NONCOPYABLE(RealtimeAnalyser); 44 public: 45 RealtimeAnalyser(); 46 virtual ~RealtimeAnalyser(); 47 48 void reset(); 49 50 size_t fftSize() const { return m_fftSize; } 51 void setFftSize(size_t size); 52 53 unsigned frequencyBinCount() const { return m_fftSize / 2; } 54 55 void setMinDecibels(float k) { m_minDecibels = k; } 56 float minDecibels() const { return static_cast<float>(m_minDecibels); } 57 58 void setMaxDecibels(float k) { m_maxDecibels = k; } 59 float maxDecibels() const { return static_cast<float>(m_maxDecibels); } 60 61 void setSmoothingTimeConstant(float k) { m_smoothingTimeConstant = k; } 62 float smoothingTimeConstant() const { return static_cast<float>(m_smoothingTimeConstant); } 63 64 #if ENABLE(WEBGL) 65 void getFloatFrequencyData(Float32Array*); 66 void getByteFrequencyData(Uint8Array*); 67 void getByteTimeDomainData(Uint8Array*); 68 #endif 69 70 // The audio thread writes input data here. 71 void writeInput(AudioBus*, size_t framesToProcess); 72 73 static const double DefaultSmoothingTimeConstant; 74 static const double DefaultMinDecibels; 75 static const double DefaultMaxDecibels; 76 77 static const unsigned DefaultFFTSize; 78 static const unsigned MaxFFTSize; 79 static const unsigned InputBufferSize; 80 81 private: 82 // The audio thread writes the input audio here. 83 AudioFloatArray m_inputBuffer; 84 unsigned m_writeIndex; 85 86 size_t m_fftSize; 87 OwnPtr<FFTFrame> m_analysisFrame; 88 void doFFTAnalysis(); 89 90 // doFFTAnalysis() stores the floating-point magnitude analysis data here. 91 AudioFloatArray m_magnitudeBuffer; 92 AudioFloatArray& magnitudeBuffer() { return m_magnitudeBuffer; } 93 94 // A value between 0 and 1 which averages the previous version of m_magnitudeBuffer with the current analysis magnitude data. 95 double m_smoothingTimeConstant; 96 97 // The range used when converting when using getByteFrequencyData(). 98 double m_minDecibels; 99 double m_maxDecibels; 100 }; 101 102 } // namespace WebCore 103 104 #endif // RealtimeAnalyser_h 105
