revised version of F746_SD_GraphicEqualizer
Dependencies: BSP_DISCO_F746NG F746_GUI F746_SAI_IO FrequencyResponseDrawer LCD_DISCO_F746NG SDFileSystem_Warning_Fixed TS_DISCO_F746NG mbed
Fork of F746_SD_GraphicEqualizer by
MyClasses_Functions/GrEqParamsCalculator.hpp@8:12aa05f3cc24, 2016-05-09 (annotated)
- Committer:
- MikamiUitOpen
- Date:
- Mon May 09 08:54:09 2016 +0000
- Revision:
- 8:12aa05f3cc24
8
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
MikamiUitOpen | 8:12aa05f3cc24 | 1 | //------------------------------------------------------------------------------ |
MikamiUitOpen | 8:12aa05f3cc24 | 2 | // Parameters calculator class of buquad unit for graphic equalizer |
MikamiUitOpen | 8:12aa05f3cc24 | 3 | // グラフィックイコライザで使う biquad フィルタの係数を計算するクラス |
MikamiUitOpen | 8:12aa05f3cc24 | 4 | // |
MikamiUitOpen | 8:12aa05f3cc24 | 5 | // 2016/05/09, Copyright (c) 2016 MIKAMI, Naoki |
MikamiUitOpen | 8:12aa05f3cc24 | 6 | //------------------------------------------------------------------------------ |
MikamiUitOpen | 8:12aa05f3cc24 | 7 | |
MikamiUitOpen | 8:12aa05f3cc24 | 8 | #ifndef GRAPHIC_EQALIZER_PARAMETER_CALCULATOR_HPP |
MikamiUitOpen | 8:12aa05f3cc24 | 9 | #define GRAPHIC_EQALIZER_PARAMETER_CALCULATOR_HPP |
MikamiUitOpen | 8:12aa05f3cc24 | 10 | |
MikamiUitOpen | 8:12aa05f3cc24 | 11 | #include "mbed.h" |
MikamiUitOpen | 8:12aa05f3cc24 | 12 | #include "BiquadGrEq.hpp" |
MikamiUitOpen | 8:12aa05f3cc24 | 13 | |
MikamiUitOpen | 8:12aa05f3cc24 | 14 | namespace Mikami |
MikamiUitOpen | 8:12aa05f3cc24 | 15 | { |
MikamiUitOpen | 8:12aa05f3cc24 | 16 | class GrEqParams |
MikamiUitOpen | 8:12aa05f3cc24 | 17 | { |
MikamiUitOpen | 8:12aa05f3cc24 | 18 | public: |
MikamiUitOpen | 8:12aa05f3cc24 | 19 | // Constructor |
MikamiUitOpen | 8:12aa05f3cc24 | 20 | GrEqParams(int bands, float fs) : BANDS_(bands), FS_(fs) {} |
MikamiUitOpen | 8:12aa05f3cc24 | 21 | |
MikamiUitOpen | 8:12aa05f3cc24 | 22 | // 係数を計算する |
MikamiUitOpen | 8:12aa05f3cc24 | 23 | BiquadGrEq::Coefs Execute(int band, float f0, float gDb, float qVal) |
MikamiUitOpen | 8:12aa05f3cc24 | 24 | { |
MikamiUitOpen | 8:12aa05f3cc24 | 25 | const float PI = 3.1415926536f; |
MikamiUitOpen | 8:12aa05f3cc24 | 26 | BiquadGrEq::Coefs coefs; |
MikamiUitOpen | 8:12aa05f3cc24 | 27 | |
MikamiUitOpen | 8:12aa05f3cc24 | 28 | float gSqrt = sqrtf(powf(10, gDb/20.0f)); |
MikamiUitOpen | 8:12aa05f3cc24 | 29 | float w0 = 2.0f*PI*f0/FS_; |
MikamiUitOpen | 8:12aa05f3cc24 | 30 | |
MikamiUitOpen | 8:12aa05f3cc24 | 31 | if ( (band != 0) && (band != BANDS_-1) ) |
MikamiUitOpen | 8:12aa05f3cc24 | 32 | { |
MikamiUitOpen | 8:12aa05f3cc24 | 33 | float alpha = sinf(w0)/(2.0f*qVal); |
MikamiUitOpen | 8:12aa05f3cc24 | 34 | float a0 = 1.0f + alpha/gSqrt; |
MikamiUitOpen | 8:12aa05f3cc24 | 35 | coefs.a1 = 2.0f*cosf(w0)/a0; |
MikamiUitOpen | 8:12aa05f3cc24 | 36 | coefs.a2 = -(1.0f - alpha/gSqrt)/a0; |
MikamiUitOpen | 8:12aa05f3cc24 | 37 | coefs.b0 = (1.0f + alpha*gSqrt)/a0; |
MikamiUitOpen | 8:12aa05f3cc24 | 38 | coefs.b1 = -coefs.a1; |
MikamiUitOpen | 8:12aa05f3cc24 | 39 | coefs.b2 = (1.0f - alpha*gSqrt)/a0; |
MikamiUitOpen | 8:12aa05f3cc24 | 40 | } |
MikamiUitOpen | 8:12aa05f3cc24 | 41 | else |
MikamiUitOpen | 8:12aa05f3cc24 | 42 | { |
MikamiUitOpen | 8:12aa05f3cc24 | 43 | w0 = (band == 0) ? w0*1.414f : w0/1.414f; |
MikamiUitOpen | 8:12aa05f3cc24 | 44 | float alpha = sinf(w0)/sqrtf(2.0f); // Q = 1/sqrt(2) |
MikamiUitOpen | 8:12aa05f3cc24 | 45 | float g_a = sqrtf(gSqrt); |
MikamiUitOpen | 8:12aa05f3cc24 | 46 | float cosW0 = cosf(w0); |
MikamiUitOpen | 8:12aa05f3cc24 | 47 | float gSqrtP1 = gSqrt+1.0f; |
MikamiUitOpen | 8:12aa05f3cc24 | 48 | float gSqrtM1 = gSqrt-1.0f; |
MikamiUitOpen | 8:12aa05f3cc24 | 49 | if (band == 0) |
MikamiUitOpen | 8:12aa05f3cc24 | 50 | { |
MikamiUitOpen | 8:12aa05f3cc24 | 51 | float a0 = gSqrtP1 + gSqrtM1*cosW0 |
MikamiUitOpen | 8:12aa05f3cc24 | 52 | + 2.0f*g_a*alpha; |
MikamiUitOpen | 8:12aa05f3cc24 | 53 | coefs.a1 = 2.0f*(gSqrtM1 + gSqrtP1*cosW0)/a0; |
MikamiUitOpen | 8:12aa05f3cc24 | 54 | coefs.a2 = -(gSqrtP1 + gSqrtM1*cosW0 |
MikamiUitOpen | 8:12aa05f3cc24 | 55 | - 2.0f*g_a*alpha)/a0; |
MikamiUitOpen | 8:12aa05f3cc24 | 56 | coefs.b0 = gSqrt*(gSqrtP1 - gSqrtM1*cosW0 |
MikamiUitOpen | 8:12aa05f3cc24 | 57 | + 2.0f*g_a*alpha)/a0; |
MikamiUitOpen | 8:12aa05f3cc24 | 58 | coefs.b1 = 2.0f*gSqrt*(gSqrtM1 |
MikamiUitOpen | 8:12aa05f3cc24 | 59 | - gSqrtP1*cosW0)/a0; |
MikamiUitOpen | 8:12aa05f3cc24 | 60 | coefs.b2 = gSqrt*(gSqrtP1 - gSqrtM1*cosW0 |
MikamiUitOpen | 8:12aa05f3cc24 | 61 | - 2.0f*g_a*alpha)/a0; |
MikamiUitOpen | 8:12aa05f3cc24 | 62 | } |
MikamiUitOpen | 8:12aa05f3cc24 | 63 | else |
MikamiUitOpen | 8:12aa05f3cc24 | 64 | { |
MikamiUitOpen | 8:12aa05f3cc24 | 65 | float a0 = gSqrtP1 - gSqrtM1*cosW0 |
MikamiUitOpen | 8:12aa05f3cc24 | 66 | + 2.0f*g_a*alpha; |
MikamiUitOpen | 8:12aa05f3cc24 | 67 | coefs.a1 = -2.0f*(gSqrtM1 - gSqrtP1*cosW0)/a0; |
MikamiUitOpen | 8:12aa05f3cc24 | 68 | coefs.a2 = -(gSqrtP1 - gSqrtM1*cosW0 |
MikamiUitOpen | 8:12aa05f3cc24 | 69 | - 2.0f*g_a*alpha)/a0; |
MikamiUitOpen | 8:12aa05f3cc24 | 70 | coefs.b0 = gSqrt*(gSqrtP1 + gSqrtM1*cosW0 |
MikamiUitOpen | 8:12aa05f3cc24 | 71 | + 2.0f*g_a*alpha)/a0; |
MikamiUitOpen | 8:12aa05f3cc24 | 72 | coefs.b1 = -2.0f*gSqrt*(gSqrtM1 + gSqrtP1*cosW0)/a0; |
MikamiUitOpen | 8:12aa05f3cc24 | 73 | coefs.b2 = gSqrt*(gSqrtP1 + gSqrtM1*cosW0 |
MikamiUitOpen | 8:12aa05f3cc24 | 74 | - 2.0f*g_a*alpha)/a0; |
MikamiUitOpen | 8:12aa05f3cc24 | 75 | } |
MikamiUitOpen | 8:12aa05f3cc24 | 76 | } |
MikamiUitOpen | 8:12aa05f3cc24 | 77 | |
MikamiUitOpen | 8:12aa05f3cc24 | 78 | return coefs; |
MikamiUitOpen | 8:12aa05f3cc24 | 79 | } |
MikamiUitOpen | 8:12aa05f3cc24 | 80 | |
MikamiUitOpen | 8:12aa05f3cc24 | 81 | private: |
MikamiUitOpen | 8:12aa05f3cc24 | 82 | const int BANDS_; |
MikamiUitOpen | 8:12aa05f3cc24 | 83 | const float FS_; |
MikamiUitOpen | 8:12aa05f3cc24 | 84 | }; |
MikamiUitOpen | 8:12aa05f3cc24 | 85 | } |
MikamiUitOpen | 8:12aa05f3cc24 | 86 | #endif // GRAPHIC_EQALIZER_PARAMETER_CALCULATOR_HPP |