不韋 呂
Output the audio signal with filtering by graphic equalizer in the *.wav file on the SD card using onboard CODEC. SD カードの *.wav ファイルのオーディオ信号をグラフィック･イコライザを通して，ボードに搭載されているCODEC で出力する．
Dependencies: F746_GUI F746_SAI_IO SD_PlayerSkeleton FrequencyResponseDrawer
Diff: MyGraphicEqualizer/GrEqualizerFrqResp.hpp
- Revision:
- 15:ef0acc9fe111
- Parent:
- 13:728576fffe65
- Child:
- 20:5c69e664e17c
diff -r ed252615db80 -r ef0acc9fe111 MyGraphicEqualizer/GrEqualizerFrqResp.hpp
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/MyGraphicEqualizer/GrEqualizerFrqResp.hpp Mon Aug 15 06:37:47 2016 +0000
@@ -0,0 +1,51 @@
+//-----------------------------------------------------------
+// グラフィックイコライザで使う IIR フィルタの周波数応答
+// Frequency response for graphic equalizer
+//
+// 2016/04/27, Copyright (c) 2016 MIKAMI, Naoki
+//-----------------------------------------------------------
+
+#ifndef GRAPHIC_EQUALIZER_FREQUENCY_RESPONSE_HPP
+#define GRAPHIC_EQUALIZER_FREQUENCY_RESPONSE_HPP
+
+#include "FrequancyResponseBase.hpp"
+#include "BiquadGrEq.hpp"
+#include "Array.hpp"
+
+namespace Mikami
+{
+ class GrEqualizerFrqResp : public FrequencyResponse
+ {
+ public:
+ GrEqualizerFrqResp(int bands)
+ : BANDS_(bands), ck_(bands) {}
+
+ virtual ~GrEqualizerFrqResp() {}
+
+ // フィルタの係数設定
+ void SetParams(BiquadGrEq::Coefs ck[])
+ { for (int n=0; n<BANDS_; n++) ck_[n] = ck[n]; }
+
+ void SetParam(BiquadGrEq::Coefs ck, int n)
+ { ck_[n] = ck; }
+
+ // 周波数応答の絶対値を返す関数, 引数: z^(-1)
+ virtual float AbsH_z(Complex u)
+ {
+ Complex h = 1;
+ for (int k=0; k<BANDS_; k++)
+ h = h*(ck_[k].b0 + (ck_[k].b1 + ck_[k].b2*u)*u)
+ /((1.0f - (ck_[k].a1 + ck_[k].a2*u)*u));
+ return abs(h);
+ }
+
+ private:
+ const int BANDS_;
+ Array<BiquadGrEq::Coefs> ck_;
+
+ // disallow copy constructor and assignment operator
+ GrEqualizerFrqResp(const GrEqualizerFrqResp&);
+ GrEqualizerFrqResp& operator=(const GrEqualizerFrqResp&);
+ };
+}
+#endif // GRAPHIC_EQUALIZER_FREQUENCY_RESPONSE_HPP