diff options
Diffstat (limited to 'apps/plugins/pdbox/PDa/extra/highpass.c')
-rw-r--r-- | apps/plugins/pdbox/PDa/extra/highpass.c | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/apps/plugins/pdbox/PDa/extra/highpass.c b/apps/plugins/pdbox/PDa/extra/highpass.c new file mode 100644 index 0000000000..88ba4564e6 --- /dev/null +++ b/apps/plugins/pdbox/PDa/extra/highpass.c | |||
@@ -0,0 +1,174 @@ | |||
1 | /* (C) Guenter Geiger <geiger@epy.co.at> */ | ||
2 | |||
3 | |||
4 | /* | ||
5 | |||
6 | These filter coefficients computations are taken from | ||
7 | http://www.harmony-central.com/Computer/Programming/Audio-EQ-Cookbook.txt | ||
8 | |||
9 | written by Robert Bristow-Johnson | ||
10 | |||
11 | */ | ||
12 | |||
13 | #include "m_pd.h" | ||
14 | #ifdef NT | ||
15 | #pragma warning( disable : 4244 ) | ||
16 | #pragma warning( disable : 4305 ) | ||
17 | #endif | ||
18 | #include <math.h> | ||
19 | #include "filters.h" | ||
20 | |||
21 | |||
22 | /* ------------------- highpass ----------------------------*/ | ||
23 | |||
24 | static t_class *highpass_class; | ||
25 | |||
26 | void highpass_bang(t_rbjfilter *x) | ||
27 | { | ||
28 | t_atom at[5]; | ||
29 | t_float omega = e_omega(x->x_freq,x->x_rate); | ||
30 | t_float alpha = e_alpha(x->x_bw* 0.01,omega); | ||
31 | t_float b1 = -(1 + cos(omega)); | ||
32 | t_float b0 = -b1/2.; | ||
33 | t_float b2 = b0; | ||
34 | t_float a0 = 1 + alpha; | ||
35 | t_float a1 = -2.*cos(omega); | ||
36 | t_float a2 = 1 - alpha; | ||
37 | |||
38 | /* post("bang %f %f %f",x->x_freq, x->x_gain, x->x_bw); */ | ||
39 | |||
40 | if (!check_stability(-a1/a0,-a2/a0,b0/a0,b1/a0,b2/a0)) { | ||
41 | post("highpass: filter unstable -> resetting"); | ||
42 | a0=1.;a1=0.;a2=0.; | ||
43 | b0=1.;b1=0.;b2=0.; | ||
44 | } | ||
45 | |||
46 | SETFLOAT(at,-a1/a0); | ||
47 | SETFLOAT(at+1,-a2/a0); | ||
48 | SETFLOAT(at+2,b0/a0); | ||
49 | SETFLOAT(at+3,b1/a0); | ||
50 | SETFLOAT(at+4,b2/a0); | ||
51 | |||
52 | outlet_list(x->x_obj.ob_outlet,&s_list,5,at); | ||
53 | } | ||
54 | |||
55 | |||
56 | void highpass_float(t_rbjfilter *x,t_floatarg f) | ||
57 | { | ||
58 | x->x_freq = f; | ||
59 | highpass_bang(x); | ||
60 | } | ||
61 | |||
62 | |||
63 | static void *highpass_new(t_floatarg f,t_floatarg bw) | ||
64 | { | ||
65 | t_rbjfilter *x = (t_rbjfilter *)pd_new(highpass_class); | ||
66 | |||
67 | x->x_rate = 44100.0; | ||
68 | outlet_new(&x->x_obj,&s_float); | ||
69 | /* floatinlet_new(&x->x_obj, &x->x_gain); */ | ||
70 | floatinlet_new(&x->x_obj, &x->x_bw); | ||
71 | if (f > 0.) x->x_freq = f; | ||
72 | if (bw > 0.) x->x_bw = bw; | ||
73 | return (x); | ||
74 | } | ||
75 | |||
76 | |||
77 | void highpass_setup(void) | ||
78 | { | ||
79 | highpass_class = class_new(gensym("highpass"), (t_newmethod)highpass_new, 0, | ||
80 | sizeof(t_rbjfilter), 0,A_DEFFLOAT,A_DEFFLOAT,0); | ||
81 | class_addbang(highpass_class,highpass_bang); | ||
82 | class_addfloat(highpass_class,highpass_float); | ||
83 | } | ||
84 | |||
85 | |||
86 | |||
87 | |||
88 | /* (C) Guenter Geiger <geiger@epy.co.at> */ | ||
89 | |||
90 | |||
91 | /* | ||
92 | |||
93 | These filter coefficients computations are taken from | ||
94 | http://www.harmony-central.com/Computer/Programming/Audio-EQ-Cookbook.txt | ||
95 | |||
96 | written by Robert Bristow-Johnson | ||
97 | |||
98 | */ | ||
99 | |||
100 | #include "m_pd.h" | ||
101 | #ifdef NT | ||
102 | #pragma warning( disable : 4244 ) | ||
103 | #pragma warning( disable : 4305 ) | ||
104 | #endif | ||
105 | #include <math.h> | ||
106 | #include "filters.h" | ||
107 | |||
108 | |||
109 | /* ------------------- highpass ----------------------------*/ | ||
110 | |||
111 | static t_class *highpass_class; | ||
112 | |||
113 | void highpass_bang(t_rbjfilter *x) | ||
114 | { | ||
115 | t_atom at[5]; | ||
116 | t_float omega = e_omega(x->x_freq,x->x_rate); | ||
117 | t_float alpha = e_alpha(x->x_bw* 0.01,omega); | ||
118 | t_float b1 = -(1 + cos(omega)); | ||
119 | t_float b0 = -b1/2.; | ||
120 | t_float b2 = b0; | ||
121 | t_float a0 = 1 + alpha; | ||
122 | t_float a1 = -2.*cos(omega); | ||
123 | t_float a2 = 1 - alpha; | ||
124 | |||
125 | /* post("bang %f %f %f",x->x_freq, x->x_gain, x->x_bw); */ | ||
126 | |||
127 | if (!check_stability(-a1/a0,-a2/a0,b0/a0,b1/a0,b2/a0)) { | ||
128 | post("highpass: filter unstable -> resetting"); | ||
129 | a0=1.;a1=0.;a2=0.; | ||
130 | b0=1.;b1=0.;b2=0.; | ||
131 | } | ||
132 | |||
133 | SETFLOAT(at,-a1/a0); | ||
134 | SETFLOAT(at+1,-a2/a0); | ||
135 | SETFLOAT(at+2,b0/a0); | ||
136 | SETFLOAT(at+3,b1/a0); | ||
137 | SETFLOAT(at+4,b2/a0); | ||
138 | |||
139 | outlet_list(x->x_obj.ob_outlet,&s_list,5,at); | ||
140 | } | ||
141 | |||
142 | |||
143 | void highpass_float(t_rbjfilter *x,t_floatarg f) | ||
144 | { | ||
145 | x->x_freq = f; | ||
146 | highpass_bang(x); | ||
147 | } | ||
148 | |||
149 | |||
150 | static void *highpass_new(t_floatarg f,t_floatarg bw) | ||
151 | { | ||
152 | t_rbjfilter *x = (t_rbjfilter *)pd_new(highpass_class); | ||
153 | |||
154 | x->x_rate = 44100.0; | ||
155 | outlet_new(&x->x_obj,&s_float); | ||
156 | /* floatinlet_new(&x->x_obj, &x->x_gain); */ | ||
157 | floatinlet_new(&x->x_obj, &x->x_bw); | ||
158 | if (f > 0.) x->x_freq = f; | ||
159 | if (bw > 0.) x->x_bw = bw; | ||
160 | return (x); | ||
161 | } | ||
162 | |||
163 | |||
164 | void highpass_setup(void) | ||
165 | { | ||
166 | highpass_class = class_new(gensym("highpass"), (t_newmethod)highpass_new, 0, | ||
167 | sizeof(t_rbjfilter), 0,A_DEFFLOAT,A_DEFFLOAT,0); | ||
168 | class_addbang(highpass_class,highpass_bang); | ||
169 | class_addfloat(highpass_class,highpass_float); | ||
170 | } | ||
171 | |||
172 | |||
173 | |||
174 | |||