不韋 呂 / Mbed 2 deprecated F746_RealtimeSpectrumAnalyzer

Realtime spectrum analyzer. Using FFT, linear prediction, or cepstrum smoothing. Version using MEMS microphone and CODEC, named "F746_RealtimeSpectrumAnalyzer_MEMS_Mic" is registered. リアルタイム スペクトル解析器．解析の手法：FFT，線形予測法，ケプストラムによる平滑化の３種類．このプログラムの説明は，CQ出版社のインターフェース誌，2016年4月号に掲載．外付けのマイクまたは他の信号源等を A0 に接続する．線形予測法，ケプストラムは，スペクトル解析の対象を音声信号に想定してパラメータを設定している．MEMS マイクと CODEC を使ったバージョンを "F746_RealtimeSpectrumAnalyzer_MEMS_Mic" として登録．

Dependencies:   BSP_DISCO_F746NG BUTTON_GROUP LCD_DISCO_F746NG TS_DISCO_F746NG UIT_FFT_Real mbed

MyClasses/Hamming.hpp@18:6630d61aeb3c, 2016-02-22 (annotated)

Committer:
MikamiUitOpen
Date:
Mon Feb 22 13:54:51 2016 +0000
Revision:
18:6630d61aeb3c
Parent:
6:b27ef8d98edc 
19

Who changed what in which revision?

UserRevisionLine numberNew contents of line
MikamiUitOpen 0:5c237fdcba23 1 //-------------------------------------------------------------------
MikamiUitOpen 0:5c237fdcba23 2 // Hamming windowing with zero-padding
MikamiUitOpen 0:5c237fdcba23 3 //
MikamiUitOpen 6:b27ef8d98edc 4 // 2015/12/17, Copyright (c) 2015 MIKAMI, Naoki
MikamiUitOpen 0:5c237fdcba23 5 //-------------------------------------------------------------------
MikamiUitOpen 0:5c237fdcba23 6
MikamiUitOpen 0:5c237fdcba23 7 #ifndef HAMMING_WINDOW_HPP
MikamiUitOpen 0:5c237fdcba23 8 #define HAMMING_WINDOW_HPP
MikamiUitOpen 0:5c237fdcba23 9
MikamiUitOpen 0:5c237fdcba23 10 #include "mbed.h"
MikamiUitOpen 0:5c237fdcba23 11
MikamiUitOpen 0:5c237fdcba23 12 namespace Mikami
MikamiUitOpen 0:5c237fdcba23 13 {
MikamiUitOpen 0:5c237fdcba23 14 class HammingWindow
MikamiUitOpen 0:5c237fdcba23 15 {
MikamiUitOpen 0:5c237fdcba23 16 public:
MikamiUitOpen 0:5c237fdcba23 17 // Constructor
MikamiUitOpen 0:5c237fdcba23 18 HammingWindow(uint16_t nData, uint16_t nFft)
MikamiUitOpen 0:5c237fdcba23 19 : N_(nData), NFFT_(nFft), w_(new float[nData])
MikamiUitOpen 0:5c237fdcba23 20 {
MikamiUitOpen 0:5c237fdcba23 21 float pi2L = 6.283185f/(float)nData;
MikamiUitOpen 0:5c237fdcba23 22 for (int k=0; k<nData; k++)
MikamiUitOpen 0:5c237fdcba23 23 w_[k] = 0.54f - 0.46f*cosf(k*pi2L);
MikamiUitOpen 0:5c237fdcba23 24 }
MikamiUitOpen 0:5c237fdcba23 25
MikamiUitOpen 0:5c237fdcba23 26 // Destructor
MikamiUitOpen 0:5c237fdcba23 27 ~HammingWindow() {delete[] w_;}
MikamiUitOpen 0:5c237fdcba23 28
MikamiUitOpen 0:5c237fdcba23 29 // Windowing
MikamiUitOpen 0:5c237fdcba23 30 void Execute(const float x[], float y[])
MikamiUitOpen 0:5c237fdcba23 31 {
MikamiUitOpen 0:5c237fdcba23 32 for (int n=0; n<N_; n++) y[n] = x[n]*w_[n];
MikamiUitOpen 0:5c237fdcba23 33 for (int n=N_; n<NFFT_; n++) y[n] = 0;
MikamiUitOpen 0:5c237fdcba23 34 }
MikamiUitOpen 6:b27ef8d98edc 35
MikamiUitOpen 6:b27ef8d98edc 36 private:
MikamiUitOpen 6:b27ef8d98edc 37 const int N_;
MikamiUitOpen 6:b27ef8d98edc 38 const int NFFT_;
MikamiUitOpen 6:b27ef8d98edc 39
MikamiUitOpen 6:b27ef8d98edc 40 float* w_;
MikamiUitOpen 6:b27ef8d98edc 41
MikamiUitOpen 6:b27ef8d98edc 42 // disallow copy constructor and assignment operator
MikamiUitOpen 6:b27ef8d98edc 43 HammingWindow(const HammingWindow& );
MikamiUitOpen 6:b27ef8d98edc 44 HammingWindow& operator=(const HammingWindow& );
MikamiUitOpen 0:5c237fdcba23 45 };
MikamiUitOpen 0:5c237fdcba23 46 }
MikamiUitOpen 0:5c237fdcba23 47 #endif // HAMMING_WINDOW_HPP