jthedering
b8cdd47f71
Added: Configuration Editor, which allows to edit configurations in a graphical user interface. Contains GUIs for most commands supported by E-APO, but as lines can also be edited directly, all commands can be used. Added: Command "GraphicEQ", which can act as a regular, fixed-band graphic equalizer (via the GUI) but also supports variable bands so that any desired frequency response can be specified. Internally, it is implemented via convolution with a generated IR. Added: Command "Convolution", which allows to convolve the signal with a user-provided impulse response to achieve e.g. equalization or reverberation effects. Improved: Configurator performs checks for registry values that are needed for the operation of E-APO, which may be changed by driver installations, fixing the values if necessary. Improved: Configurator shows which is the default device as a hint to the user.
147 lines
3.6 KiB
C++
147 lines
3.6 KiB
C++
/*
|
|
This file is part of EqualizerAPO, a system-wide equalizer.
|
|
Copyright (C) 2013 Jonas Thedering
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License along
|
|
with this program; if not, write to the Free Software Foundation, Inc.,
|
|
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
*/
|
|
|
|
#include "stdafx.h"
|
|
#include "BiQuad.h"
|
|
|
|
using namespace std;
|
|
|
|
BiQuad::BiQuad(Type type, double dbGain, double freq, double srate, double bandwidthOrQOrS, bool isBandwidth)
|
|
{
|
|
double A;
|
|
if(type == PEAKING || type == LOW_SHELF || type == HIGH_SHELF)
|
|
A = pow(10, dbGain / 40);
|
|
else
|
|
A = pow(10, dbGain / 20);
|
|
double omega = 2 * M_PI * freq / srate;
|
|
double sn = sin(omega);
|
|
double cs = cos(omega);
|
|
double alpha;
|
|
double beta = -1;
|
|
|
|
if (type == LOW_SHELF || type == HIGH_SHELF) // S
|
|
{
|
|
alpha = sn/2 * sqrt((A + 1/A) * (1/bandwidthOrQOrS - 1) + 2);
|
|
beta = 2 * sqrt(A) * alpha;
|
|
}
|
|
else if(isBandwidth) // BW
|
|
alpha = sn * sinh(M_LN2/2 * bandwidthOrQOrS * omega / sn);
|
|
else // Q
|
|
alpha = sn / (2 * bandwidthOrQOrS);
|
|
|
|
double b0, b1, b2, a0, a1, a2;
|
|
|
|
switch(type)
|
|
{
|
|
case LOW_PASS:
|
|
b0 = (1 - cs) /2;
|
|
b1 = 1 - cs;
|
|
b2 = (1 - cs) /2;
|
|
a0 = 1 + alpha;
|
|
a1 = -2 * cs;
|
|
a2 = 1 - alpha;
|
|
break;
|
|
case HIGH_PASS:
|
|
b0 = (1 + cs) /2;
|
|
b1 = -(1 + cs);
|
|
b2 = (1 + cs) /2;
|
|
a0 = 1 + alpha;
|
|
a1 = -2 * cs;
|
|
a2 = 1 - alpha;
|
|
break;
|
|
case BAND_PASS:
|
|
b0 = alpha;
|
|
b1 = 0;
|
|
b2 = -alpha;
|
|
a0 = 1 + alpha;
|
|
a1 = -2 * cs;
|
|
a2 = 1 - alpha;
|
|
break;
|
|
case NOTCH:
|
|
b0 = 1;
|
|
b1 = -2 * cs;
|
|
b2 = 1;
|
|
a0 = 1 + alpha;
|
|
a1 = -2 * cs;
|
|
a2 = 1 - alpha;
|
|
break;
|
|
case ALL_PASS:
|
|
b0 = 1 - alpha;
|
|
b1 = -2 * cs;
|
|
b2 = 1 + alpha;
|
|
a0 = 1 + alpha;
|
|
a1 = -2 * cs;
|
|
a2 = 1 - alpha;
|
|
break;
|
|
case PEAKING:
|
|
b0 = 1 + (alpha * A);
|
|
b1 = -2 * cs;
|
|
b2 = 1 - (alpha * A);
|
|
a0 = 1 + (alpha / A);
|
|
a1 = -2 * cs;
|
|
a2 = 1 - (alpha / A);
|
|
break;
|
|
case LOW_SHELF:
|
|
b0 = A * ((A + 1) - (A - 1) * cs + beta);
|
|
b1 = 2 * A * ((A - 1) - (A + 1) * cs);
|
|
b2 = A * ((A + 1) - (A - 1) * cs - beta);
|
|
a0 = (A + 1) + (A - 1) * cs + beta;
|
|
a1 = -2 * ((A - 1) + (A + 1) * cs);
|
|
a2 = (A + 1) + (A - 1) * cs - beta;
|
|
break;
|
|
case HIGH_SHELF:
|
|
b0 = A * ((A + 1) + (A - 1) * cs + beta);
|
|
b1 = -2 * A * ((A - 1) + (A + 1) * cs);
|
|
b2 = A * ((A + 1) + (A - 1) * cs - beta);
|
|
a0 = (A + 1) - (A - 1) * cs + beta;
|
|
a1 = 2 * ((A - 1) - (A + 1) * cs);
|
|
a2 = (A + 1) - (A - 1) * cs - beta;
|
|
break;
|
|
}
|
|
|
|
this->a0 = b0 / a0;
|
|
this->a[0] = b1 / a0;
|
|
this->a[1] = b2 / a0;
|
|
this->a[2] = a1 / a0;
|
|
this->a[3] = a2 / a0;
|
|
|
|
x1 = 0;
|
|
x2 = 0;
|
|
y1 = 0;
|
|
y2 = 0;
|
|
}
|
|
|
|
double BiQuad::gainAt(double freq, double srate)
|
|
{
|
|
double omega = 2 * M_PI * freq / srate;
|
|
double sn = sin(omega/2.0);
|
|
double phi = sn * sn;
|
|
double b0 = this->a0;
|
|
double b1 = this->a[0];
|
|
double b2 = this->a[1];
|
|
double a0 = 1.0;
|
|
double a1 = this->a[2];
|
|
double a2 = this->a[3];
|
|
|
|
double dbGain = 10*log10( pow(b0+b1+b2, 2) - 4*(b0*b1 + 4*b0*b2 + b1*b2)*phi + 16*b0*b2*phi*phi )
|
|
-10*log10( pow(a0+a1+a2, 2) - 4*(a0*a1 + 4*a0*a2 + a1*a2)*phi + 16*a0*a2*phi*phi );
|
|
|
|
return dbGain;
|
|
}
|