不韋 呂
Demo program of digital signal processing: Variable LPF/HPF, Vocal canceller, Pitch shifter, Reverbrator. ディジタル信号処理のデモプログラム． 遮断周波数可変 LPF/HPF，ボーカルキャンセラ，ピッチシフタ，残響生成器．
Dependencies: Array_Matrix F446_AD_DA UIT_AQM1602 mbed
Diff: SignalProcessing/WeaverModulator.hpp
- Revision:
- 0:fa74b1130cc3
- Child:
- 5:503bd366fd73
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/SignalProcessing/WeaverModulator.hpp Sun Jan 29 09:11:30 2017 +0000
@@ -0,0 +1,79 @@
+//--------------------------------------------------------------
+// Weaver 変調器
+// 入力信号の帯域： 0.1 kHz ---- 9.9 kHz
+// 帯域中央の周波数： 5.0 kHz
+// 低域通過フィルタの遮断周波数： 4.9 kHz
+
+// 2017/01/28, Copyright (c) 2017 MIKAMI, Naoki
+//--------------------------------------------------------------
+
+#ifndef WEAVER_MODULATOR_HPP
+#define WEAVER_MODULATOR_HPP
+
+#include "IIR_Cascade.hpp"
+#include "Coefficients.hpp" // Coeffisients of LPF and DC-cut filter
+#include "Array.hpp"
+using namespace Mikami;
+
+class FrqShifter : public SignalProcessing
+{
+public:
+ FrqShifter(float fS)
+ : lpfC_(WEAVER_ORDER_, weaver_g0Lpf_, weaver_ck_),
+ lpfS_(WEAVER_ORDER_, weaver_g0Lpf_, weaver_ck_),
+ dcCut_(weaver_c1_),
+ FS_(fS), PI2_(3.1415926536f*2), F_B_(5000)
+ {
+ lpfC_.Clear();
+ lpfS_.Clear();
+
+ dPhi1_ = F_B_*PI2_/FS_;
+ dPhi2_ = dPhi1_;
+ phi1_ = 0;
+ phi2_ = 0;
+ }
+
+ virtual float Execute(float xn1, float xn2)
+ {
+ float xn = (xn1 + xn2)*0.5f;
+ xn = dcCut_.Execute(weaver_g0_*xn); // DC 成分除去
+
+ float mpyC = xn*cosf(phi1_);
+ float mpyS = xn*sinf(phi1_);
+
+ // LPF
+ float mpyC_Lpf = lpfC_.Execute(mpyC);
+ float mpyS_Lpf = lpfS_.Execute(mpyS);
+
+ float mpyC_C = mpyC_Lpf*cosf(phi2_);
+ float mpyS_S = mpyS_Lpf*sinf(phi2_);
+
+ float yn = 2.0f*(mpyC_C + mpyS_S);
+
+ phi1_ = phi1_ + dPhi1_;
+ if (phi1_ > PI2_) phi1_ = phi1_ - PI2_;
+ phi2_ = phi2_ + dPhi2_;
+ if (phi2_ > PI2_) phi2_ = phi2_ - PI2_;
+
+ return yn;
+ }
+
+ // 周波数のシフト量を設定
+ void SetFrequensy(float fShift)
+ { dPhi2_ = (fShift + F_B_)*PI2_/FS_; }
+
+private:
+ // Weaver 変調器で使う低域通過フィルタ
+ IirCascade lpfC_;
+ IirCascade lpfS_;
+ // 直流分除去フィルタ
+ Biquad dcCut_;
+
+ const float FS_;
+ const float PI2_;
+ const float F_B_; // 中心周波数
+
+ float phi1_, dPhi1_;
+ float phi2_, dPhi2_;
+};
+#endif // WEAVER_MODULATOR_HPP