不韋 呂
Realtime sound spectrogram using FFT or linear prediction. Spectrogram is displayed on the display of PC. リアルタイム･スペクトログラム．解析の手法：FFT，線形予測法．スペクトログラムは PC のディスプレー装置に表示される．PC 側のプログラム：F446_Spectrogram.
Dependencies: Array_Matrix mbed SerialTxRxIntr F446_AD_DA UIT_FFT_Real
Diff: MySpectrogram/AnalyzerBase.cpp
- Revision:
- 6:c38ec7939609
- Parent:
- 0:a539141b9dec
--- a/MySpectrogram/AnalyzerBase.cpp Sun Oct 07 05:15:04 2018 +0000
+++ b/MySpectrogram/AnalyzerBase.cpp Sun Nov 04 10:41:02 2018 +0000
@@ -1,7 +1,7 @@
//-------------------------------------------------------
// Base abstract class for spectrum analysis
//
-// 2017/02/09, Copyright (c) 2017 MIKAMI, Naoki
+// 2018/11/04, Copyright (c) 2018 MIKAMI, Naoki
//-------------------------------------------------------
#include "AnalyzerBase.hpp"
@@ -18,7 +18,13 @@
// 高域強調
for (int n=0; n<N_DATA_-1; n++)
xData_[n] = xn[n+1] - b1_*xn[n];
-
+
+ // 直流分を除去
+ float sum = 0;
+ for (int n=0; n<N_FFT_; n++) sum = sum + xData_[n];
+ float ave = sum/N_FFT_;
+ for (int n=0; n<N_FFT_; n++) xData_[n] = xData_[n] - ave;
+
// 窓掛け
wHm_.Execute(xData_, wData_);