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/Hamming.hpp@6:b3885567877c, 2017-04-10 (annotated)

Committer:
MikamiUitOpen
Date:
Mon Apr 10 13:43:07 2017 +0000
Revision:
6:b3885567877c
Parent:
3:6a2c8ff46f73 
7

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 6:b3885567877c 4 // 2017/04/10, Copyright (c) 2017 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 2:1f092ac020e1 11 #include "Array.hpp"
MikamiUitOpen 0:9470a174c910 12
MikamiUitOpen 0:9470a174c910 13 namespace Mikami
MikamiUitOpen 0:9470a174c910 14 {
MikamiUitOpen 0:9470a174c910 15 class HammingWindow
MikamiUitOpen 0:9470a174c910 16 {
MikamiUitOpen 0:9470a174c910 17 public:
MikamiUitOpen 0:9470a174c910 18 // Constructor
MikamiUitOpen 0:9470a174c910 19 HammingWindow(uint16_t nData, uint16_t nFft)
MikamiUitOpen 2:1f092ac020e1 20 : N_(nData), NFFT_(nFft), w_(nData)
MikamiUitOpen 0:9470a174c910 21 {
MikamiUitOpen 0:9470a174c910 22 float pi2L = 6.283185f/(float)nData;
MikamiUitOpen 0:9470a174c910 23 for (int k=0; k<nData; k++)
MikamiUitOpen 0:9470a174c910 24 w_[k] = 0.54f - 0.46f*cosf(k*pi2L);
MikamiUitOpen 0:9470a174c910 25 }
MikamiUitOpen 6:b3885567877c 26
MikamiUitOpen 0:9470a174c910 27 // Windowing
MikamiUitOpen 0:9470a174c910 28 void Execute(const float x[], float y[])
MikamiUitOpen 0:9470a174c910 29 {
MikamiUitOpen 0:9470a174c910 30 for (int n=0; n<N_; n++) y[n] = x[n]*w_[n];
MikamiUitOpen 0:9470a174c910 31 for (int n=N_; n<NFFT_; n++) y[n] = 0;
MikamiUitOpen 0:9470a174c910 32 }
MikamiUitOpen 0:9470a174c910 33
MikamiUitOpen 0:9470a174c910 34 private:
MikamiUitOpen 0:9470a174c910 35 const int N_;
MikamiUitOpen 0:9470a174c910 36 const int NFFT_;
MikamiUitOpen 6:b3885567877c 37
MikamiUitOpen 2:1f092ac020e1 38 Array<float> w_;
MikamiUitOpen 0:9470a174c910 39
MikamiUitOpen 0:9470a174c910 40 // disallow copy constructor and assignment operator
MikamiUitOpen 0:9470a174c910 41 HammingWindow(const HammingWindow& );
MikamiUitOpen 0:9470a174c910 42 HammingWindow& operator=(const HammingWindow& );
MikamiUitOpen 0:9470a174c910 43 };
MikamiUitOpen 0:9470a174c910 44 }
MikamiUitOpen 0:9470a174c910 45 #endif // HAMMING_WINDOW_HPP