-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathfilters_lib.genexpr
185 lines (157 loc) · 4.77 KB
/
filters_lib.genexpr
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
// Genexpr code used to create a basic filters library which started from the comb
// and allpass filters of the Freeverb's model.
// -----------------------------------------------------------------------------
comb_freeverb (sig, del, fbgain, damping)
{
Delay delay_1((samplerate*0.05)); // estimated table size for efficient comb-filtering
History zeta(0);
delval = (floor(del/44100.*samplerate));
del_read = delay_1.read(delval);
//out1 = del_read;
dampval = clamp(damping, 0., 1.);
damp = del_read * dampval;
negin2 = 1 - dampval;
negh = zeta * negin2;
zdamp = damp + negh;
fbval = clamp(fbgain, -0.99, 0.99); //Clamped value to guarantee stability
feedback = zdamp * fbval;
engine = sig + feedback;
zeta_next_10 = fixdenorm(zdamp);
delay_1.write(engine);
zeta = zeta_next_10;
return del_read;
}
//out1 = comb_freeverb(in1, in2, in3, in4);
//------------------------------------------------------------------------------
ccrma_lbcf (sig, del, fbgain, damping)
{
Delay delay_1((samplerate*0.05));
History zeta(0);
delval = (floor(del/44100*samplerate));
del_read = delay_1.read(delval);
dampval = clamp(damping, 0.01, 1.0);
damp = (del_read*dampval) + (zeta*(1-dampval));
fbval = clamp(fbgain, 0., 0.99);
lpfeedback = damp*fbval;
engine = sig+lpfeedback;
zeta_next_10 = fixdenorm(del_read);
delay_1.write(engine);
zeta = zeta_next_10;
return engine;
}
//out1 = ccrma_lbcf (in1, in2, in3, in4);
//------------------------------------------------------------------------------
ccrma_lbcf (sig, del, fbgain)
{
Delay delay_1((samplerate*0.05));
History zeta(0);
delval = (floor(del/44100*samplerate));
del_read = delay_1.read(delval);
lp = (del_read*0.8) + (zeta*-0.2);
fbval = clamp(fbgain, 0., 0.99);
lpfeedback = lp*fbval;
engine = sig+lpfeedback;
zeta_next_10 = fixdenorm(del_read);
delay_1.write(engine);
zeta = zeta_next_10;
return engine;
}
//out1 = ccrma_lbcf (in1, in2, in3);
//------------------------------------------------------------------------------
ccrma_ffcf (sig, del, ffgain)
{
Delay delay_1((samplerate*0.05));
delval = (floor(del/44100.*samplerate));
del_read = delay_1.read(delval);
ffval = clamp(ffgain, -0.99, 0.99);
feedforward = del_read * ffval;
engine = sig + feedforward;
//out1 = add_6;
delay_1.write(sig);
return engine;
}
//out1 = ccrma_ffcf (in1, in2, in3);
//------------------------------------------------------------------------------
ccrma_onepole (sig, fc)
{
History zeta(0);
cutoff = clamp(fc, 1, 20000);
a0 = sin(cutoff*(pi/(samplerate*0.5)));
b0 = 1-(clamp(a0, -0.99, 0.99));
zetafb = zeta*b0;
engine = (sig*a0)+zetafb;
zeta_next_12 = fixdenorm(engine);
zeta = zeta_next_12;
return engine;
}
//out1 = ccrma_onepole(in1, in2);
//------------------------------------------------------------------------------
allpass_freeverb (sig, del, fbgain)
{
Delay delay_1((samplerate*0.05));
delval = (floor(del/44100.*samplerate));
del_read = delay_1.read(delval);
engine = sig - del_read;
//out1 = engine;
fbval = clamp(fbgain, 0., 0.5);
fb_gain = del_read * fbval;
zeta = sig + fb_gain;
zeta_bitmask = fixdenorm(zeta);
delay_1.write(zeta_bitmask);
return engine;
}
//------------------------------------------------------------------------------
Schroeder_allpass (sig, del, fbgain)
{
Delay delay_1((samplerate*0.05));
delval = (floor(del/44100*samplerate));
del_read = delay_1.read(delval);
fbval = clamp(fbgain, 0.01, 0.99);
fbgain = del_read*fbval;
zeta1 = sig + fbgain;
invfbgain = zeta1 * fbval*-1;
zeta2 = del_read + invfbgain;
delay_1.write(zeta1);
return zeta2;
}
//out1 = Schroeder_allpass (in1, in2, in3);
//------------------------------------------------------------------------------
ccrma_lbcf (sig, del, fbgain, lf_shelf)
{
Delay delay_1((samplerate*0.05));
delval = (floor(del/44100.*samplerate));
del_read = delay_1.read(delval);
fbval = clamp(fbgain, -0.99, 0.99);
feedback = del_read * (fbval*-1);
lf_feedback = ccrma_onepole (feedback, lf_shelf);
engine = sig + lf_feedback;
//out1 = add_6;
delay_1.write(engine);
return engine;
}
//------------------------------------------------------------------------------
resonfilter (sig, centerfreq, Q, gain)
{
// filter input/output history:
History x1, x2, y1, y2;
x = sig; // input signal
cf = centerfreq; // cutoff frequency
q = Q; // Q factor
filtergain = clamp(gain, 0., 100.); // gain of the filter signal
// calculate coefficients:
twopi_over_sr = twopi/samplerate;
bw = cf/q; // bandwidth
r = exp(-bw*twopi_over_sr);
c1 = 2*r*cos(cf * twopi_over_sr);
c2 = -r*r;
// generate output:
y = (1-r) * (x - r*x2) + c1*y1 + c2*y2;
out = (y*filtergain);
// filter history cascade:
y2 = y1;
y1 = y;
x2 = x1;
x1 = x;
return out;
}
//------------------------------------------------------------------------------