不韋 呂 / F746_Spectrogram

Realtime spectrogram for DISCO-F746NG. On-board MEMS microphone is used for input sound signal. リアルタイムスペクトログラム．入力：MEMSマイク

Dependencies:   F746_GUI F746_SAI_IO UIT_FFT_Real

MyClasses_Functions/FFT_Analysis.cpp

Committer:
MikamiUitOpen
Date:
2016-05-22
Revision:
0:9470a174c910
Child:
2:1f092ac020e1

File content as of revision 0:9470a174c910:

//-------------------------------------------------------
//  Class for spectrum analysis using FFT
//
//  2015/12/15, Copyright (c) 2015 MIKAMI, Naoki
//-------------------------------------------------------

#include "FFT_Analysis.hpp"

namespace Mikami
{
    FftAnalyzer::FftAnalyzer(int nData, int nFft)
        : AnalyzerBase(nData, nFft, nFft),
          yFft_(new Complex[nFft/2+1]) {}

    FftAnalyzer::~FftAnalyzer()
    {
        delete[] yFft_;
    }

    void FftAnalyzer::Analyze(const float xn[], float yn[])
    {
        fft_.Execute(xn, yFft_);    // Execute FFT
        
        // Translate to dB
        for (int n=0; n<=N_FFT_/2; n++)
            yn[n] = 10.0f*log10f(Norm(yFft_[n]));
    }
}