不韋 呂
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
Diff: MySpectrogram/Hamming.hpp
- Revision:
- 3:6a2c8ff46f73
- Parent:
- 2:1f092ac020e1
- Child:
- 6:b3885567877c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/MySpectrogram/Hamming.hpp Mon Aug 15 06:51:01 2016 +0000
@@ -0,0 +1,48 @@
+//-------------------------------------------------------------------
+// Hamming windowing with zero-padding
+//
+// 2016/07/23, Copyright (c) 2016 MIKAMI, Naoki
+//-------------------------------------------------------------------
+
+#ifndef HAMMING_WINDOW_HPP
+#define HAMMING_WINDOW_HPP
+
+#include "mbed.h"
+#include "Array.hpp"
+
+namespace Mikami
+{
+ class HammingWindow
+ {
+ public:
+ // Constructor
+ HammingWindow(uint16_t nData, uint16_t nFft)
+ : N_(nData), NFFT_(nFft), w_(nData)
+ {
+ float pi2L = 6.283185f/(float)nData;
+ for (int k=0; k<nData; k++)
+ w_[k] = 0.54f - 0.46f*cosf(k*pi2L);
+ }
+
+ // Destructor
+ virtual ~HammingWindow() {}
+
+ // Windowing
+ void Execute(const float x[], float y[])
+ {
+ for (int n=0; n<N_; n++) y[n] = x[n]*w_[n];
+ for (int n=N_; n<NFFT_; n++) y[n] = 0;
+ }
+
+ private:
+ const int N_;
+ const int NFFT_;
+
+ Array<float> w_;
+
+ // disallow copy constructor and assignment operator
+ HammingWindow(const HammingWindow& );
+ HammingWindow& operator=(const HammingWindow& );
+ };
+}
+#endif // HAMMING_WINDOW_HPP