不韋 呂 / Mbed 2 deprecated F446_Spectrogram

Realtime sound spectrogram using FFT or linear prediction. Spectrogram is displayed on the display of PC. リアルタイム･スペクトログラム．解析の手法：FFT，線形予測法．スペクトログラムは PC のディスプレー装置に表示される．PC 側のプログラム：F446_Spectrogram.

Dependencies:   Array_Matrix mbed SerialTxRxIntr F446_AD_DA UIT_FFT_Real

MySpectrogram/AnalyzerBase.hpp

Committer:
MikamiUitOpen
Date:
2019-11-24
Revision:
7:5ba884060d3b
Parent:
6:c38ec7939609

File content as of revision 7:5ba884060d3b:

//-------------------------------------------------------
//  Base abstract class for spectrum analysis (Header)
//
//  2018/11/04, Copyright (c) 2018 MIKAMI, Naoki
//-------------------------------------------------------

#ifndef BASE_ANALYZER_HPP
#define BASE_ANALYZER_HPP

#include "Array.hpp"
#include "fftReal.hpp"
#include "Hamming.hpp"

namespace Mikami
{
    class AnalyzerBase
    {
    public:
        // nData: Number of data to be analyzed
        // nFft:  Number of FFT points
        // nUse:  FFT, cepstrum: window width + zero padding
        //        Linear prediction: window width
        AnalyzerBase(int nData, int nFft, int nUse);
        virtual ~AnalyzerBase() {}
        void Execute(const float xn[], float db[]);
        // 高域強調の程度を決める定数の設定（b1 = 1 で差分，b1 = 0 で高域強調なし）
        void SetHighEmphasizer(float b1) { b1_ = b1; }

    protected:
        const int N_DATA_;
        const int N_FFT_;

        FftReal fft_;
                
        float Norm(Complex x)
        { return x.real()*x.real() + x.imag()*x.imag(); }

    private:
        HammingWindow wHm_;
        float b1_;

        Array<float> xData_;    // data to be analyzed
        Array<float> wData_;    // windowd data

        virtual void Analyze(const float wData[], float db[]) = 0;

        // disallow copy constructor and assignment operator
        AnalyzerBase(const AnalyzerBase& );
        AnalyzerBase& operator=(const AnalyzerBase& );
    };
}
#endif  // BASE_ANALYZER_HPP