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/Hamming.hpp@0:9470a174c910, 2016-05-22 (annotated)

Committer:
MikamiUitOpen
Date:
Sun May 22 06:28:40 2016 +0000
Revision:
0:9470a174c910
Child:
2:1f092ac020e1
1

Who changed what in which revision?

UserRevisionLine numberNew contents of line
MikamiUitOpen 0:9470a174c910 1 //-------------------------------------------------------------------
MikamiUitOpen 0:9470a174c910 2 // Hamming windowing with zero-padding
MikamiUitOpen 0:9470a174c910 3 //
MikamiUitOpen 0:9470a174c910 4 // 2015/12/17, Copyright (c) 2015 MIKAMI, Naoki
MikamiUitOpen 0:9470a174c910 5 //-------------------------------------------------------------------
MikamiUitOpen 0:9470a174c910 6
MikamiUitOpen 0:9470a174c910 7 #ifndef HAMMING_WINDOW_HPP
MikamiUitOpen 0:9470a174c910 8 #define HAMMING_WINDOW_HPP
MikamiUitOpen 0:9470a174c910 9
MikamiUitOpen 0:9470a174c910 10 #include "mbed.h"
MikamiUitOpen 0:9470a174c910 11
MikamiUitOpen 0:9470a174c910 12 namespace Mikami
MikamiUitOpen 0:9470a174c910 13 {
MikamiUitOpen 0:9470a174c910 14 class HammingWindow
MikamiUitOpen 0:9470a174c910 15 {
MikamiUitOpen 0:9470a174c910 16 public:
MikamiUitOpen 0:9470a174c910 17 // Constructor
MikamiUitOpen 0:9470a174c910 18 HammingWindow(uint16_t nData, uint16_t nFft)
MikamiUitOpen 0:9470a174c910 19 : N_(nData), NFFT_(nFft), w_(new float[nData])
MikamiUitOpen 0:9470a174c910 20 {
MikamiUitOpen 0:9470a174c910 21 float pi2L = 6.283185f/(float)nData;
MikamiUitOpen 0:9470a174c910 22 for (int k=0; k<nData; k++)
MikamiUitOpen 0:9470a174c910 23 w_[k] = 0.54f - 0.46f*cosf(k*pi2L);
MikamiUitOpen 0:9470a174c910 24 }
MikamiUitOpen 0:9470a174c910 25
MikamiUitOpen 0:9470a174c910 26 // Destructor
MikamiUitOpen 0:9470a174c910 27 ~HammingWindow() {delete[] w_;}
MikamiUitOpen 0:9470a174c910 28
MikamiUitOpen 0:9470a174c910 29 // Windowing
MikamiUitOpen 0:9470a174c910 30 void Execute(const float x[], float y[])
MikamiUitOpen 0:9470a174c910 31 {
MikamiUitOpen 0:9470a174c910 32 for (int n=0; n<N_; n++) y[n] = x[n]*w_[n];
MikamiUitOpen 0:9470a174c910 33 for (int n=N_; n<NFFT_; n++) y[n] = 0;
MikamiUitOpen 0:9470a174c910 34 }
MikamiUitOpen 0:9470a174c910 35
MikamiUitOpen 0:9470a174c910 36 private:
MikamiUitOpen 0:9470a174c910 37 const int N_;
MikamiUitOpen 0:9470a174c910 38 const int NFFT_;
MikamiUitOpen 0:9470a174c910 39
MikamiUitOpen 0:9470a174c910 40 float* w_;
MikamiUitOpen 0:9470a174c910 41
MikamiUitOpen 0:9470a174c910 42 // disallow copy constructor and assignment operator
MikamiUitOpen 0:9470a174c910 43 HammingWindow(const HammingWindow& );
MikamiUitOpen 0:9470a174c910 44 HammingWindow& operator=(const HammingWindow& );
MikamiUitOpen 0:9470a174c910 45 };
MikamiUitOpen 0:9470a174c910 46 }
MikamiUitOpen 0:9470a174c910 47 #endif // HAMMING_WINDOW_HPP