不韋 呂 / Mbed 2 deprecated F746_SpectralAnalysis_Example

Spectrum analyzer using DISCO-F746NG. Spectrum is calculated by FFT or linear prediction. The vowel data is in "vowel_data.hpp"

Dependencies:   BSP_DISCO_F746NG LCD_DISCO_F746NG TS_DISCO_F746NG UIT_FFT_Real mbed BUTTON_GROUP

SpactrumAnalysisClasses/Hamming.hpp@0:c35b8a23a863, 2015-10-26 (annotated)

Committer:
MikamiUitOpen
Date:
Mon Oct 26 08:06:57 2015 +0000
Revision:
0:c35b8a23a863
1

Who changed what in which revision?

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MikamiUitOpen 0:c35b8a23a863 1 //-------------------------------------------------------------------
MikamiUitOpen 0:c35b8a23a863 2 // Hamming windowing with zero-padding
MikamiUitOpen 0:c35b8a23a863 3 // Copyright (c) 2014 MIKAMI, Naoki, 2014/12/21
MikamiUitOpen 0:c35b8a23a863 4 //-------------------------------------------------------------------
MikamiUitOpen 0:c35b8a23a863 5
MikamiUitOpen 0:c35b8a23a863 6 #ifndef HAMMING_WINDOW_HPP
MikamiUitOpen 0:c35b8a23a863 7 #define HAMMING_WINDOW_HPP
MikamiUitOpen 0:c35b8a23a863 8
MikamiUitOpen 0:c35b8a23a863 9 #include "mbed.h"
MikamiUitOpen 0:c35b8a23a863 10
MikamiUitOpen 0:c35b8a23a863 11 namespace Mikami
MikamiUitOpen 0:c35b8a23a863 12 {
MikamiUitOpen 0:c35b8a23a863 13 class HammingWindow
MikamiUitOpen 0:c35b8a23a863 14 {
MikamiUitOpen 0:c35b8a23a863 15 private:
MikamiUitOpen 0:c35b8a23a863 16 const int N_;
MikamiUitOpen 0:c35b8a23a863 17 const int NFFT_;
MikamiUitOpen 0:c35b8a23a863 18
MikamiUitOpen 0:c35b8a23a863 19 float* w_;
MikamiUitOpen 0:c35b8a23a863 20
MikamiUitOpen 0:c35b8a23a863 21 public:
MikamiUitOpen 0:c35b8a23a863 22 // Constructor
MikamiUitOpen 0:c35b8a23a863 23 HammingWindow(uint16_t nData, uint16_t nFft)
MikamiUitOpen 0:c35b8a23a863 24 : N_(nData), NFFT_(nFft)
MikamiUitOpen 0:c35b8a23a863 25 {
MikamiUitOpen 0:c35b8a23a863 26 w_ = new float[nData];
MikamiUitOpen 0:c35b8a23a863 27 float pi2L = 6.283185f/(float)nData;
MikamiUitOpen 0:c35b8a23a863 28 for (int k=0; k<nData; k++)
MikamiUitOpen 0:c35b8a23a863 29 w_[k] = 0.54f - 0.46f*cosf(k*pi2L);
MikamiUitOpen 0:c35b8a23a863 30 }
MikamiUitOpen 0:c35b8a23a863 31
MikamiUitOpen 0:c35b8a23a863 32 // Destructor
MikamiUitOpen 0:c35b8a23a863 33 ~HammingWindow() {delete[] w_;}
MikamiUitOpen 0:c35b8a23a863 34
MikamiUitOpen 0:c35b8a23a863 35 // Windowing
MikamiUitOpen 0:c35b8a23a863 36 void Execute(const float x[], float y[])
MikamiUitOpen 0:c35b8a23a863 37 {
MikamiUitOpen 0:c35b8a23a863 38 for (int n=0; n<N_; n++) y[n] = x[n]*w_[n];
MikamiUitOpen 0:c35b8a23a863 39 for (int n=N_; n<NFFT_; n++) y[n] = 0;
MikamiUitOpen 0:c35b8a23a863 40 }
MikamiUitOpen 0:c35b8a23a863 41 };
MikamiUitOpen 0:c35b8a23a863 42 }
MikamiUitOpen 0:c35b8a23a863 43 #endif // HAMMING_WINDOW_HPP
MikamiUitOpen 0:c35b8a23a863 44