## Copyright (C) 2020 Jens
## 
## 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 3 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, see
## <https://www.gnu.org/licenses/>.

## -*- texinfo -*- 
## @deftypefn {} {@var{retval} =} eq_eval (@var{input1}, @var{input2})
##
## @seealso{}
## @end deftypefn

## Author: Jens <jens@orion>
## Created: 2020-06-22

function points = eq_eval (filename_in)
P = 1
fs = 48000
[x, fs] = audioread(filename_in);
filename_out = to_filename_out(filename_in, "out");

points = [];
points = addPoint_peak_notch(points, 120, 60, 6, P);
points = addPoint_peak_notch(points, 540, 480, 3, P);
points = addPoint_peak_notch(points, 1250, 2500, -3, P);
points = addPoint_peak_notch(points, 8000, 8000, 12, P);
points = addPoint_peak_notch(points, 4000, 8000, -12, P);
points = addPoint_peak_notch(points, 15625, 1000, -16, P);

Np = length(points)
y = x;

for n = 1:Np,
	P = points(n).P;
	gain = 10^(points(n).g/20);
	
	[B,A] = boost3(fs, points(n).f, points(n).b, gain, P);
	
	for p=1:P,
		y = filter(B(p,:), A(p,:), y);
	end
endfor
audiowrite(filename_out, y./max(y), fs)

% Audition
for n = 1:Np,
	P = points(n).P;
	gain = 10^(points(n).g/20);
	
	[B,A] = boost3(fs, points(n).f, points(n).b, gain, P);
	
	for p=1:P,
		y = filter(B(p,:), A(p,:), x) - x;
	end
	suffix = sprintf("%d_%d_%d", points(n).f, points(n).b, points(n).g);
	filename_aud = to_filename_out(filename_in, suffix);
	
	audiowrite(filename_aud, y, fs)

endfor

endfunction

function points_out = addPoint_peak_notch(points_in, fc_Hz, bw_Hz, gain_dB, P)
	p.f = fc_Hz;
	p.b = bw_Hz;
	p.g = gain_dB;
	p.P = P;
	p.type = "PeakNotch";
	points_out = [points_in p]; 
endfunction