Audio singal input and output example for DISCO-F746. Input: MEMS mic, Output: CN10 OUT, Acoustic effect: echo and frequency shift. DISCO-F746 によるオーディオ信号入出力.入力:MEMS マイク,出力:CN10 OUT,音響効果:エコー,周波数変換.
Dependencies: F746_GUI F746_SAI_IO
Diff: MyAcousticEffector_MIC/ReverbUnit.hpp
- Revision:
- 5:7de034938856
- Parent:
- 0:f064b50f238e
- Child:
- 10:56f2f01df983
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/MyAcousticEffector_MIC/ReverbUnit.hpp Mon Aug 15 06:53:47 2016 +0000 @@ -0,0 +1,106 @@ +//-------------------------------------------------------------- +// Reverb unit +// 2016/04/12, Copyright (c) 2016 MIKAMI, Naoki +//-------------------------------------------------------------- + +#ifndef REVERB_UNIT_HPP +#define REVERB_UNIT_HPP + +#include "mbed.h" + +namespace Mikami +{ + // Base class for reverb unit + class Reverb + { + public: + // Constructor + Reverb(int delay) : ptr_(0), delay_(delay) + { + un_ = new float[delay]; + Clear(); + } + + ~Reverb() + { delete[] un_; } + + // Execute of filter (pure virtual function) + virtual float Execute(float x) = 0; + + // Clear internal delay elements + void Clear() + { for (int n=0; n<delay_; n++) un_[n] = 0; } + + protected: + float Get() { return un_[ptr_]; } + + float Get(int n) + { + int k = ptr_ + n; + if (k > delay_) k -= delay_; + if (k < 0) k += delay_; + return un_[k]; + } + + void Set(float x) + { + un_[ptr_] = x; + if (++ptr_ >= delay_) ptr_ = 0; + } + private: + int ptr_; + int delay_; + float *un_; // for delay + Reverb(const Reverb&); + Reverb& operator=(const Reverb&); + }; + + // Reverb unit using comb filter + class CombFilter : public Reverb + { + public: + // Constructor + CombFilter(float g, int delay) + : Reverb(delay), G0_(g) {} + + // Execute comb filter + virtual float Execute(float x) + { + float yn = Reverb::Get(); + Reverb::Set(x + G0_*yn); + return yn; + } + + // Execute comb filter with variable delay + float Execute(float x, int n) + { + float yn = Reverb::Get(n); + Reverb::Set(x + G0_*yn); + return yn; + } + + private: + const float G0_; + }; + + // Reverb unit using allpass filter + class AllPassFilter : public Reverb + { + public: + // Constructor + AllPassFilter(float g, int delay) + : Reverb(delay), G0_(g) {} + + // Execute allpass filter + virtual float Execute(float x) + { + float un = x + G0_*Reverb::Get(); + float yn = -G0_*un + Reverb::Get(); + Reverb::Set(un); + return yn; + } + private: + const float G0_; + }; +} +#endif // REVERB_UNIT_HPP