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| author | Peter D'Hoye <peter.dhoye@gmail.com> | 2009-05-22 21:58:48 +0000 |
|---|---|---|
| committer | Peter D'Hoye <peter.dhoye@gmail.com> | 2009-05-22 21:58:48 +0000 |
| commit | 513389b4c1bc8afe4b2dc9947c534bfeb105e3da (patch) | |
| tree | 10e673b35651ac567fed2eda0c679c7ade64cbc6 /apps/plugins/pdbox/PDa/extra/equalizer.c | |
| parent | 95fa7f6a2ef466444fbe3fe87efc6d5db6b77b36 (diff) | |
| download | rockbox-513389b4c1bc8afe4b2dc9947c534bfeb105e3da.zip rockbox-513389b4c1bc8afe4b2dc9947c534bfeb105e3da.tar.gz rockbox-513389b4c1bc8afe4b2dc9947c534bfeb105e3da.tar.bz2 rockbox-513389b4c1bc8afe4b2dc9947c534bfeb105e3da.tar.xz | |
Add FS #10214. Initial commit of the original PDa code for the GSoC Pure Data plugin project of Wincent Balin. Stripped some non-sourcefiles and added a rockbox readme that needs a bit more info from Wincent. Is added to CATEGORIES and viewers, but not yet to SUBDIRS (ie doesn't build yet)
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@21044 a1c6a512-1295-4272-9138-f99709370657
Diffstat (limited to 'apps/plugins/pdbox/PDa/extra/equalizer.c')
| -rw-r--r-- | apps/plugins/pdbox/PDa/extra/equalizer.c | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/apps/plugins/pdbox/PDa/extra/equalizer.c b/apps/plugins/pdbox/PDa/extra/equalizer.c new file mode 100644 index 0000000..1d21c40 --- /dev/null +++ b/apps/plugins/pdbox/PDa/extra/equalizer.c @@ -0,0 +1,178 @@ +/* (C) Guenter Geiger <geiger@epy.co.at> */
+
+
+/*
+
+ These filter coefficients computations are taken from
+ http://www.harmony-central.com/Computer/Programming/Audio-EQ-Cookbook.txt
+
+ written by Robert Bristow-Johnson
+
+*/
+
+#include "m_pd.h"
+#ifdef NT
+#pragma warning( disable : 4244 )
+#pragma warning( disable : 4305 )
+#endif
+#include <math.h>
+#include "filters.h"
+
+
+
+/* ------------------- equ ----------------------------*/
+static t_class *equ_class;
+
+void equ_bang(t_rbjfilter *x)
+{
+ t_atom at[5];
+ t_float omega = e_omega(x->x_freq,x->x_rate);
+ t_float alpha = e_alpha(x->x_bw*0.01,omega);
+ t_float b0 = 1 + alpha*e_A(x->x_gain);
+ t_float b1 = -2.*cos(omega);
+ t_float b2 = 1 - alpha*e_A(x->x_gain);
+ t_float a0 = 1 + alpha/e_A(x->x_gain);
+ t_float a1 = -2.*cos(omega);
+ t_float a2 = 1 - alpha/e_A(x->x_gain);
+
+/* post("bang %f %f %f",x->x_freq, x->x_gain, x->x_bw);*/
+
+ if (!check_stability(-a1/a0,-a2/a0,b0/a0,b1/a0,b2/a0)) {
+ post("equ: filter unstable -> resetting");
+ a0=1.;a1=0.;a2=0.;
+ b0=1.;b1=0.;b2=0.;
+ }
+
+ SETFLOAT(at,-a1/a0);
+ SETFLOAT(at+1,-a2/a0);
+ SETFLOAT(at+2,b0/a0);
+ SETFLOAT(at+3,b1/a0);
+ SETFLOAT(at+4,b2/a0);
+
+ outlet_list(x->x_obj.ob_outlet,&s_list,5,at);
+}
+
+
+void equ_float(t_rbjfilter *x,t_floatarg f)
+{
+ x->x_freq = f;
+ equ_bang(x);
+}
+
+
+static void *equ_new(t_floatarg f,t_floatarg g,t_floatarg bw)
+{
+ t_rbjfilter *x = (t_rbjfilter *)pd_new(equ_class);
+
+ x->x_rate = 44100.0;
+ outlet_new(&x->x_obj,&s_float);
+ floatinlet_new(&x->x_obj, &x->x_gain);
+ floatinlet_new(&x->x_obj, &x->x_bw);
+ if (f > 0.) x->x_freq = f;
+ if (bw > 0.) x->x_bw = bw;
+ if (g != 0.) x->x_gain = g;
+ return (x);
+}
+
+
+void equalizer_setup(void)
+{
+ equ_class = class_new(gensym("equalizer"), (t_newmethod)equ_new, 0,
+ sizeof(t_rbjfilter), 0,A_DEFFLOAT,A_DEFFLOAT,A_DEFFLOAT,0);
+ class_addbang(equ_class,equ_bang);
+ class_addfloat(equ_class,equ_float);
+}
+
+
+
+
+
+/* (C) Guenter Geiger <geiger@epy.co.at> */
+
+
+/*
+
+ These filter coefficients computations are taken from
+ http://www.harmony-central.com/Computer/Programming/Audio-EQ-Cookbook.txt
+
+ written by Robert Bristow-Johnson
+
+*/
+
+#include "m_pd.h"
+#ifdef NT
+#pragma warning( disable : 4244 )
+#pragma warning( disable : 4305 )
+#endif
+#include <math.h>
+#include "filters.h"
+
+
+
+/* ------------------- equ ----------------------------*/
+static t_class *equ_class;
+
+void equ_bang(t_rbjfilter *x)
+{
+ t_atom at[5];
+ t_float omega = e_omega(x->x_freq,x->x_rate);
+ t_float alpha = e_alpha(x->x_bw*0.01,omega);
+ t_float b0 = 1 + alpha*e_A(x->x_gain);
+ t_float b1 = -2.*cos(omega);
+ t_float b2 = 1 - alpha*e_A(x->x_gain);
+ t_float a0 = 1 + alpha/e_A(x->x_gain);
+ t_float a1 = -2.*cos(omega);
+ t_float a2 = 1 - alpha/e_A(x->x_gain);
+
+/* post("bang %f %f %f",x->x_freq, x->x_gain, x->x_bw);*/
+
+ if (!check_stability(-a1/a0,-a2/a0,b0/a0,b1/a0,b2/a0)) {
+ post("equ: filter unstable -> resetting");
+ a0=1.;a1=0.;a2=0.;
+ b0=1.;b1=0.;b2=0.;
+ }
+
+ SETFLOAT(at,-a1/a0);
+ SETFLOAT(at+1,-a2/a0);
+ SETFLOAT(at+2,b0/a0);
+ SETFLOAT(at+3,b1/a0);
+ SETFLOAT(at+4,b2/a0);
+
+ outlet_list(x->x_obj.ob_outlet,&s_list,5,at);
+}
+
+
+void equ_float(t_rbjfilter *x,t_floatarg f)
+{
+ x->x_freq = f;
+ equ_bang(x);
+}
+
+
+static void *equ_new(t_floatarg f,t_floatarg g,t_floatarg bw)
+{
+ t_rbjfilter *x = (t_rbjfilter *)pd_new(equ_class);
+
+ x->x_rate = 44100.0;
+ outlet_new(&x->x_obj,&s_float);
+ floatinlet_new(&x->x_obj, &x->x_gain);
+ floatinlet_new(&x->x_obj, &x->x_bw);
+ if (f > 0.) x->x_freq = f;
+ if (bw > 0.) x->x_bw = bw;
+ if (g != 0.) x->x_gain = g;
+ return (x);
+}
+
+
+void equalizer_setup(void)
+{
+ equ_class = class_new(gensym("equalizer"), (t_newmethod)equ_new, 0,
+ sizeof(t_rbjfilter), 0,A_DEFFLOAT,A_DEFFLOAT,A_DEFFLOAT,0);
+ class_addbang(equ_class,equ_bang);
+ class_addfloat(equ_class,equ_float);
+}
+
+
+
+
+
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