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* Copyright (C) 2010, Google Inc. All rights reserved.
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
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* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
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* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
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* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#ifndef RealtimeAnalyser_h
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#define RealtimeAnalyser_h
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#include "AudioArray.h"
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#include <wtf/Forward.h>
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#include <wtf/Noncopyable.h>
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#include <wtf/OwnPtr.h>
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class RealtimeAnalyser {
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WTF_MAKE_NONCOPYABLE(RealtimeAnalyser);
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virtual ~RealtimeAnalyser();
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size_t fftSize() const { return m_fftSize; }
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bool setFftSize(size_t);
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unsigned frequencyBinCount() const { return m_fftSize / 2; }
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void setMinDecibels(float k) { m_minDecibels = k; }
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float minDecibels() const { return static_cast<float>(m_minDecibels); }
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void setMaxDecibels(float k) { m_maxDecibels = k; }
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float maxDecibels() const { return static_cast<float>(m_maxDecibels); }
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void setSmoothingTimeConstant(float k) { m_smoothingTimeConstant = k; }
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float smoothingTimeConstant() const { return static_cast<float>(m_smoothingTimeConstant); }
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void getFloatFrequencyData(Float32Array*);
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void getByteFrequencyData(Uint8Array*);
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void getByteTimeDomainData(Uint8Array*);
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// The audio thread writes input data here.
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void writeInput(AudioBus*, size_t framesToProcess);
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static const double DefaultSmoothingTimeConstant;
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static const double DefaultMinDecibels;
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static const double DefaultMaxDecibels;
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static const unsigned DefaultFFTSize;
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static const unsigned MinFFTSize;
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static const unsigned MaxFFTSize;
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static const unsigned InputBufferSize;
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// The audio thread writes the input audio here.
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AudioFloatArray m_inputBuffer;
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unsigned m_writeIndex;
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OwnPtr<FFTFrame> m_analysisFrame;
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// doFFTAnalysis() stores the floating-point magnitude analysis data here.
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AudioFloatArray m_magnitudeBuffer;
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AudioFloatArray& magnitudeBuffer() { return m_magnitudeBuffer; }
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// A value between 0 and 1 which averages the previous version of m_magnitudeBuffer with the current analysis magnitude data.
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double m_smoothingTimeConstant;
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// The range used when converting when using getByteFrequencyData().
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} // namespace WebCore
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#endif // RealtimeAnalyser_h