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

Revision:
0:9470a174c910
Child:
2:1f092ac020e1
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MyClasses_Functions/Hamming.hpp	Sun May 22 06:28:40 2016 +0000
@@ -0,0 +1,47 @@
+//-------------------------------------------------------------------
+//  Hamming windowing with zero-padding
+//
+//  2015/12/17, Copyright (c) 2015 MIKAMI, Naoki
+//-------------------------------------------------------------------
+
+#ifndef HAMMING_WINDOW_HPP
+#define HAMMING_WINDOW_HPP
+
+#include "mbed.h"
+
+namespace Mikami
+{
+    class HammingWindow
+    {
+    public:
+        // Constructor
+        HammingWindow(uint16_t nData, uint16_t nFft)
+                : N_(nData), NFFT_(nFft), w_(new float[nData])
+        {
+            float pi2L = 6.283185f/(float)nData;
+            for (int k=0; k<nData; k++)
+                w_[k] = 0.54f - 0.46f*cosf(k*pi2L);
+        }
+        
+        // Destructor
+        ~HammingWindow() {delete[] w_;}
+        
+        // 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_;
+                
+        float* w_;
+
+        // disallow copy constructor and assignment operator
+        HammingWindow(const HammingWindow& );
+        HammingWindow& operator=(const HammingWindow& );
+    };
+}
+#endif  // HAMMING_WINDOW_HPP