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

MySpectrogram/FFT_Analysis.cpp

Committer:
MikamiUitOpen
Date:
2017-04-10
Revision:
6:b3885567877c
Parent:
3:6a2c8ff46f73

File content as of revision 6:b3885567877c:

//-------------------------------------------------------
//  Class for spectrum analysis using FFT
//
//  2017/03/30, Copyright (c) 2017 MIKAMI, Naoki
//-------------------------------------------------------

#include "FFT_Analysis.hpp"

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

    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]));
    }
}