Add parametric EQ and auto-wah.

git-svn-id: http://svn.drobilla.net/lad/trunk/plugins/fomp.lv2@4735 a436a847-0d15-0410-975c-d299462d15a1

10 files changed, 818 insertions, 1 deletions

diff --git a/fomp.lv2/autowah.ttl b/fomp.lv2/autowah.ttl
new file mode 100644
index 0000000..ec99fb3
--- /dev/null
+++ b/fomp.lv2/autowah.ttl
@@ -0,0 +1,73 @@
+@prefix doap: <http://usefulinc.com/ns/doap#> .
+@prefix foaf: <http://xmlns.com/foaf/0.1/> .
+@prefix lv2: <http://lv2plug.in/ns/lv2core#> .
+@prefix owl: <http://www.w3.org/2002/07/owl#> .
+@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
+@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
+@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
+
+<http://drobilla.net/plugins/fomp/autowah>
+	a lv2:Plugin ,
+		lv2:FilterPlugin ;
+	doap:name "Auto-wah" ;
+	lv2:microVersion 0 ;
+	lv2:minorVersion 0 ;
+	lv2:optionalFeature lv2:hardRTCapable ;
+	lv2:port [
+		a lv2:AudioPort ,
+			lv2:InputPort ;
+		lv2:index 0 ;
+		lv2:name "Input" ;
+		lv2:symbol "in"
+	] , [
+		a lv2:AudioPort ,
+			lv2:OutputPort ;
+		lv2:index 1 ;
+		lv2:name "Output" ;
+		lv2:symbol "out"
+	] , [
+		a lv2:ControlPort ,
+			lv2:InputPort ;
+		lv2:default 0.0 ;
+		lv2:index 2 ;
+		lv2:maximum 20.0 ;
+		lv2:minimum -20.0 ;
+		lv2:name "Drive" ;
+		lv2:symbol "drive"
+	] , [
+		a lv2:ControlPort ,
+			lv2:InputPort ;
+		lv2:default 0.5 ;
+		lv2:index 3 ;
+		lv2:maximum 1.0 ;
+		lv2:minimum 0.0 ;
+		lv2:name "Decay" ;
+		lv2:symbol "decay"
+	] , [
+		a lv2:ControlPort ,
+			lv2:InputPort ;
+		lv2:default 0.5 ;
+		lv2:index 4 ;
+		lv2:maximum 1.0 ;
+		lv2:minimum 0.0 ;
+		lv2:name "Range" ;
+		lv2:symbol "range"
+	] , [
+		a lv2:ControlPort ,
+			lv2:InputPort ;
+		lv2:default 0.5 ;
+		lv2:index 5 ;
+		lv2:maximum 1.0 ;
+		lv2:minimum 0.0 ;
+		lv2:name "Freq" ;
+		lv2:symbol "freq"
+	] , [
+		a lv2:ControlPort ,
+			lv2:InputPort ;
+		lv2:default 0.5 ;
+		lv2:index 6 ;
+		lv2:maximum 1.0 ;
+		lv2:minimum 0.0 ;
+		lv2:name "Mix" ;
+		lv2:symbol "mix"
+	] .
diff --git a/fomp.lv2/manifest.ttl.in b/fomp.lv2/manifest.ttl.in
index 80291ad..ad71d53 100644
--- a/fomp.lv2/manifest.ttl.in
+++ b/fomp.lv2/manifest.ttl.in
@@ -78,3 +78,13 @@ fomp:rec_vco
 	a lv2:Plugin ;
 	rdfs:seeAlso <rec_vco.ttl> ;
 	lv2:binary <blvco@LIB_EXT@> .
+
+fomp:parametric1
+	a lv2:Plugin ;
+	rdfs:seeAlso <parametric1.ttl> ;
+	lv2:binary <filters@LIB_EXT@> .
+
+fomp:autowah
+	a lv2:Plugin ;
+	rdfs:seeAlso <autowah.ttl> ;
+	lv2:binary <autowah@LIB_EXT@> .
diff --git a/fomp.lv2/parametric1.ttl b/fomp.lv2/parametric1.ttl
new file mode 100644
index 0000000..8118107
--- /dev/null
+++ b/fomp.lv2/parametric1.ttl
@@ -0,0 +1,195 @@
+@prefix doap: <http://usefulinc.com/ns/doap#> .
+@prefix fomp: <http://drobilla.net/plugins/fomp/> .
+@prefix lv2: <http://lv2plug.in/ns/lv2core#> .
+@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
+@prefix units: <http://lv2plug.in/ns/extensions/units#> .
+
+fomp:parametric1
+	a lv2:Plugin ,
+		lv2:ParaEQPlugin ;
+	doap:name "4-Band Parametric Filter" ;
+	lv2:microVersion 0 ;
+	lv2:minorVersion 0 ;
+	lv2:optionalFeature lv2:hardRTCapable ;
+	lv2:port [
+		a lv2:AudioPort ,
+			lv2:InputPort ;
+		lv2:index 0 ;
+		lv2:name "Input" ;
+		lv2:symbol "in"
+	] , [
+		a lv2:AudioPort ,
+			lv2:OutputPort ;
+		lv2:index 1 ;
+		lv2:name "Output" ;
+		lv2:symbol "out"
+	] , [
+		a lv2:ControlPort ,
+			lv2:InputPort ;
+		lv2:default 0.0 ;
+		lv2:index 2 ;
+		lv2:name "Filter" ;
+		lv2:portProperty lv2:toggled ;
+		lv2:symbol "filter"
+	] , [
+		a lv2:ControlPort ,
+			lv2:InputPort ;
+		lv2:default 0.0 ;
+		lv2:index 3 ;
+		lv2:maximum 20.0 ;
+		lv2:minimum -20.0 ;
+		lv2:name "Gain" ;
+		lv2:symbol "gain"
+	] , [
+		a lv2:ControlPort ,
+			lv2:InputPort ;
+		lv2:default 0.0 ;
+		lv2:index 4 ;
+		lv2:name "Section 1" ;
+		lv2:portProperty lv2:toggled ;
+		lv2:symbol "sec_1"
+	] , [
+		a lv2:ControlPort ,
+			lv2:InputPort ;
+		lv2:default 200.0 ;
+		lv2:index 5 ;
+		lv2:maximum 2000.0 ;
+		lv2:minimum 20.0 ;
+		lv2:name "Frequency 1" ;
+		lv2:portProperty <http://lv2plug.in/ns/ext/port-props#logarithmic> ;
+		lv2:symbol "freq_1" ;
+		units:unit units:hz
+	] , [
+		a lv2:ControlPort ,
+			lv2:InputPort ;
+		lv2:default 1.0 ;
+		lv2:index 6 ;
+		lv2:maximum 8.0 ;
+		lv2:minimum 0.125 ;
+		lv2:name "Bandwidth 1" ;
+		lv2:portProperty <http://lv2plug.in/ns/ext/port-props#logarithmic> ;
+		lv2:symbol "bw_1"
+	] , [
+		a lv2:ControlPort ,
+			lv2:InputPort ;
+		lv2:default 0.0 ;
+		lv2:index 7 ;
+		lv2:maximum 20.0 ;
+		lv2:minimum -20.0 ;
+		lv2:name "Gain 1" ;
+		lv2:symbol "gain_1"
+	] , [
+		a lv2:ControlPort ,
+			lv2:InputPort ;
+		lv2:default 0.0 ;
+		lv2:index 8 ;
+		lv2:name "Section 2" ;
+		lv2:portProperty lv2:toggled ;
+		lv2:symbol "sec_2"
+	] , [
+		a lv2:ControlPort ,
+			lv2:InputPort ;
+		lv2:default 400.0 ;
+		lv2:index 9 ;
+		lv2:maximum 4000.0 ;
+		lv2:minimum 40.0 ;
+		lv2:name "Frequency 2" ;
+		lv2:portProperty <http://lv2plug.in/ns/ext/port-props#logarithmic> ;
+		lv2:symbol "freq_2" ;
+		units:unit units:hz
+	] , [
+		a lv2:ControlPort ,
+			lv2:InputPort ;
+		lv2:default 1.0 ;
+		lv2:index 10 ;
+		lv2:maximum 8.0 ;
+		lv2:minimum 0.125 ;
+		lv2:name "Bandwidth 2" ;
+		lv2:portProperty <http://lv2plug.in/ns/ext/port-props#logarithmic> ;
+		lv2:symbol "bw_2"
+	] , [
+		a lv2:ControlPort ,
+			lv2:InputPort ;
+		lv2:default 0.0 ;
+		lv2:index 11 ;
+		lv2:maximum 20.0 ;
+		lv2:minimum -20.0 ;
+		lv2:name "Gain 2" ;
+		lv2:symbol "gain_2"
+	] , [
+		a lv2:ControlPort ,
+			lv2:InputPort ;
+		lv2:default 0.0 ;
+		lv2:index 12 ;
+		lv2:name "Section 3" ;
+		lv2:portProperty lv2:toggled ;
+		lv2:symbol "sec_3"
+	] , [
+		a lv2:ControlPort ,
+			lv2:InputPort ;
+		lv2:default 1000.0 ;
+		lv2:index 13 ;
+		lv2:maximum 10000.0 ;
+		lv2:minimum 100.0 ;
+		lv2:name "Frequency 3" ;
+		lv2:portProperty <http://lv2plug.in/ns/ext/port-props#logarithmic> ;
+		lv2:symbol "freq_3" ;
+		units:unit units:hz
+	] , [
+		a lv2:ControlPort ,
+			lv2:InputPort ;
+		lv2:default 1.0 ;
+		lv2:index 14 ;
+		lv2:maximum 8.0 ;
+		lv2:minimum 0.125 ;
+		lv2:name "Bandwidth 3" ;
+		lv2:portProperty <http://lv2plug.in/ns/ext/port-props#logarithmic> ;
+		lv2:symbol "bw_3"
+	] , [
+		a lv2:ControlPort ,
+			lv2:InputPort ;
+		lv2:default 0.0 ;
+		lv2:index 15 ;
+		lv2:maximum 20.0 ;
+		lv2:minimum -20.0 ;
+		lv2:name "Gain 3" ;
+		lv2:symbol "gain_3"
+	] , [
+		a lv2:ControlPort ,
+			lv2:InputPort ;
+		lv2:default 0.0 ;
+		lv2:index 16 ;
+		lv2:name "Section 4" ;
+		lv2:portProperty lv2:toggled ;
+		lv2:symbol "sec_4"
+	] , [
+		a lv2:ControlPort ,
+			lv2:InputPort ;
+		lv2:default 2000.0 ;
+		lv2:index 17 ;
+		lv2:maximum 20000.0 ;
+		lv2:minimum 200.0 ;
+		lv2:name "Frequency 4" ;
+		lv2:portProperty <http://lv2plug.in/ns/ext/port-props#logarithmic> ;
+		lv2:symbol "freq_4" ;
+		units:unit units:hz
+	] , [
+		a lv2:ControlPort ,
+			lv2:InputPort ;
+		lv2:default 1.0 ;
+		lv2:index 18 ;
+		lv2:maximum 8.0 ;
+		lv2:minimum 0.125 ;
+		lv2:name "Bandwidth 4" ;
+		lv2:portProperty <http://lv2plug.in/ns/ext/port-props#logarithmic> ;
+		lv2:symbol "bw_4"
+	] , [
+		a lv2:ControlPort ,
+			lv2:InputPort ;
+		lv2:default 0.0 ;
+		lv2:index 19 ;
+		lv2:maximum 20.0 ;
+		lv2:minimum -20.0 ;
+		lv2:name "Gain 4" ;
+		lv2:symbol "gain_4"
+	] .
diff --git a/src/autowah.cc b/src/autowah.cc
new file mode 100644
index 0000000..a18c8d3
--- /dev/null
+++ b/src/autowah.cc
@@ -0,0 +1,130 @@
+/*
+    Copyright (C) 2009 Fons Adriaensen <fons@kokkinizita.net>
+    
+    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., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+
+#include <math.h>
+#include <string.h>
+#include "autowah.h"
+
+
+void Ladspa_Autowah::setport (PortIndex port, PortData *data)
+{
+	_port [port] = (float*)data;
+}
+
+
+#define G_RES 4.0f
+#define F_MIN 300.0f
+#define F_RAT 10
+#define B_MIN 0.03f
+#define B_RAT 4
+#define T_MIN 0.05f 
+#define T_LOG 2
+
+
+void Ladspa_Autowah::active (bool act)
+{
+    if (! act) return;
+
+    _wbase = F_MIN * 6.28f / _fsam;
+    _bbase = B_MIN;
+    _rfact = 64.0f / (_fsam * T_MIN);
+    _z1 = _z2 = 0;
+    _s1 = _s2 = 0;
+    _gx = _gy = 0;
+    _dr = 0;
+}
+
+
+void Ladspa_Autowah::runproc (SampleCount len, bool add)
+{
+    int   i, k;
+    float *inp = _port [A_INP];
+    float *out = _port [A_OUT];
+    float z1, z2, s1, s2, gx, gy;
+    float ds1, ds2, dgx, dgy;
+    float gd, rf, md, fr, dr;
+    float b, p, t, w, x, y;
+
+    gx = _gx;
+    gy = _gy;
+    t = _port [C_OPMIX][0];
+    _gy = G_RES * t;
+    _gx = _gy + 1 - t;
+    dgx = (_gx - gx) / len;
+    dgy = (_gy - gy) / len;
+
+    gd = 10 * powf (10.0f, 0.05f * _port [C_DRIVE][0]);
+    rf = 1.0f - _rfact / powf (10.0f, T_LOG * _port [C_DECAY][0]);
+    md = _port [C_RANGE][0];
+    fr = _port [C_FREQ][0];
+
+    z1 = _z1;
+    z2 = _z2;
+    s1 = _s1;
+    s2 = _s2;
+    dr = _dr;
+
+    while (len)
+    {
+	k = (len > 80) ? 64 : len;
+
+	p = 0;
+	for (i = 0; i < k; i++)
+	{
+	    x = inp [i];
+	    p += x * x;
+	}
+	p = gd * sqrtf (p / k);
+
+	if (p > dr) dr += 0.1f *(p - dr);
+	if (dr > md) dr = md;
+	t = dr + fr; 
+	dr = dr * rf + 1e-10f;
+	w = _wbase  * (1 + (F_RAT - 1) * t * t); 
+	b = w * _bbase * (1 + (B_RAT - 1) * t);
+        if (w > 0.7f) w = 0.7f;
+
+	_s1 = -cosf (w);
+	_s2 = (1 - b) / (1 + b);
+	ds1 = (_s1 - s1) / k;
+	ds2 = (_s2 - s2) / k;
+  
+	for (i = 0; i < k; i++)
+	{
+	    s1 += ds1;
+	    s2 += ds2;
+            gx += dgx;
+            gy += dgy;
+            x = inp [i];
+            y = x - s2 * z2;
+            out [i] = gx * x - gy * (z2 + s2 * y);                           
+            y -= s1 * z1;
+            z2 = z1 + s1 * y;
+            z1 = y + 1e-10f;
+	}
+	inp += k;
+	out += k;
+	len -= k;
+    }
+
+    _z1 = z1;
+    _z2 = z2;
+    _dr = dr;
+}
+
diff --git a/src/autowah.h b/src/autowah.h
new file mode 100644
index 0000000..79a3d9c
--- /dev/null
+++ b/src/autowah.h
@@ -0,0 +1,52 @@
+/*
+    Copyright (C) 2009 Fons Adriaensen <fons@kokkinizita.net>
+    
+    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., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+
+#ifndef __AUTOWAH_H
+#define __AUTOWAH_H
+
+
+#include "ladspaplugin.h"
+
+
+class Ladspa_Autowah : public LadspaPlugin
+{
+public:
+
+    enum { A_INP, A_OUT, C_DRIVE, C_DECAY, C_RANGE, C_FREQ, C_OPMIX, NPORT };
+
+    Ladspa_Autowah (SampleRate fsam) : LadspaPlugin (fsam) {}
+    virtual void setport (PortIndex port, PortData *data);  
+    virtual void active  (bool act);  
+    virtual void runproc (SampleCount len, bool add);
+    virtual ~Ladspa_Autowah (void) {}  
+
+private:
+
+    float     *_port [NPORT];
+    float      _wbase;
+    float      _bbase;
+    float      _rfact;
+    float      _z1, _z2;
+    float      _s1, _s2;
+    float      _gx, _gy;
+    float      _dr;
+};
+
+
+#endif
diff --git a/src/autowah_lv2.cc b/src/autowah_lv2.cc
new file mode 100644
index 0000000..29a64ee
--- /dev/null
+++ b/src/autowah_lv2.cc
@@ -0,0 +1,56 @@
+/*
+  Copyright (C) 2012 David Robillard <d@drobilla.net>
+    
+  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., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include <stddef.h>
+
+#include "autowah.h"
+#include "plugin_lv2.h"
+
+extern "C" {
+
+static LV2_Handle
+instantiate(const LV2_Descriptor*     descriptor,
+            double                    rate,
+            const char*               bundle_path,
+            const LV2_Feature* const* features)
+{
+	return new Ladspa_Autowah(rate);
+}
+
+static const LV2_Descriptor descriptor = {
+	"http://drobilla.net/plugins/fomp/autowah",
+	instantiate,
+	connect_port,
+	activate,
+	run,
+	deactivate,
+	cleanup,
+	NULL
+};
+
+LV2_SYMBOL_EXPORT
+const LV2_Descriptor*
+lv2_descriptor(uint32_t index)
+{
+	switch (index) {
+	case 0:  return &descriptor;
+	default: return NULL;
+	}
+}
+
+}  // extern "C"
diff --git a/src/filters.cc b/src/filters.cc
new file mode 100644
index 0000000..8c93696
--- /dev/null
+++ b/src/filters.cc
@@ -0,0 +1,113 @@
+/*
+    Copyright (C) 2004-2009 Fons Adriaensen <fons@kokkinizita.net>
+    
+    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., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+
+#include <string.h>
+#include "filters.h"
+#include "exp2ap.h"
+
+
+void Ladspa_Paramfilt::setport (PortIndex port, PortData *data)
+{
+	_port [port] = (float*)data;
+}
+
+
+void Ladspa_Paramfilt::active (bool act)
+{
+    int j;
+
+    if (! act) return;
+    _fade = 0;
+    _gain = 1;
+    for (j = 0; j < NSECT; j++) _sect [j].init ();   
+}
+
+
+void Ladspa_Paramfilt::runproc (SampleCount len, bool add)
+{
+    int   i, j, k;
+    float *aip = _port [AIP];
+    float *aop = _port [AOP];
+    float *p, sig [48];
+    float t, g, d;
+    float fgain;
+    float sfreq [NSECT];
+    float sband [NSECT];
+    float sgain [NSECT];
+
+    fgain = exp2ap (0.1661 * _port [GAIN][0]);
+    for (j = 0; j < NSECT; j++)
+    {
+	t = _port [SECT + 4 * j + Paramsect::FREQ][0] / _fsam; 
+        if (t < 0.0002) t = 0.0002;
+        if (t > 0.4998) t = 0.4998;
+        sfreq [j] = t;        
+        sband [j] = _port [SECT + 4 * j + Paramsect::BAND][0];
+        if (_port [SECT + 4 * j + Paramsect::SECT][0] > 0) sgain [j] = exp2ap (0.1661 * _port [SECT + 4 * j + Paramsect::GAIN][0]);
+        else sgain [j] = 1.0;
+    }
+
+    while (len)
+    {
+        k = (len > 48) ? 32 : len;
+        
+        t = fgain;
+        g = _gain;
+        if      (t > 1.25 * g) t = 1.25 * g;
+        else if (t < 0.80 * g) t = 0.80 * g;
+        _gain = t;
+        d = (t - g) / k;
+        for (i = 0; i < k; i++) 
+	{
+	    g += d;
+            sig [i] = g * aip [i];
+	}
+
+        for (j = 0; j < NSECT; j++) _sect [j].proc (k, sig, sfreq [j], sband [j], sgain [j]);
+                  
+        j = _fade;
+        g = j / 16.0;
+	p = 0;
+	if (_port [FILT][0] > 0)
+	{
+	    if (j == 16) p = sig;
+	    else ++j;
+	}
+	else
+	{
+	    if (j == 0) p = aip;
+	    else --j;
+	}
+	_fade = j;  
+	if (p) memcpy (aop, p, k * sizeof (float));
+	else
+	{
+	    d = (j / 16.0 - g) / k;
+	    for (i = 0; i < k; i++)
+	    {
+		g += d;
+		aop [i] = g * sig [i] + (1 - g) * aip [i];
+	    }
+	}
+	aip += k;
+	aop += k;
+	len -= k;
+    }
+}
+
diff --git a/src/filters.h b/src/filters.h
new file mode 100644
index 0000000..3000870
--- /dev/null
+++ b/src/filters.h
@@ -0,0 +1,130 @@
+/*
+    Copyright (C) 2004-2009 Fons Adriaensen <fons@kokkinizita.net>
+    
+    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., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+
+#ifndef __FILTERS_H
+#define __FILTERS_H
+
+#include <math.h>
+#include "ladspaplugin.h"
+
+
+class Paramsect
+{
+public:
+
+    enum { SECT, FREQ, BAND, GAIN };
+
+    void init (void)
+    {
+        _f = 0.25f;
+        _b = _g = 1.0f;
+	_a = _s1 = _s2 = _z1 = _z2 = 0.0f;
+    }
+    
+    void proc (int k, float *sig, float f, float b, float g)
+    {
+        float s1, s2, d1, d2, a, da, x, y;
+        bool  u2 = false;
+
+        s1 = _s1;        
+        s2 = _s2;
+        a = _a; 
+        d1 = 0;
+        d2 = 0;
+        da = 0;
+
+        if (f != _f)
+	{
+  	    if      (f < 0.5f * _f) f = 0.5f * _f;
+            else if (f > 2.0f * _f) f = 2.0f * _f;
+            _f = f;
+            _s1 = -cosf (6.283185f * f);
+            d1 = (_s1 - s1) / k;           
+            u2 = true;
+	}             
+       
+        if (g != _g)
+	{
+            if      (g < 0.5f * _g) g = 0.5f * _g;
+            else if (g > 2.0f * _g) g = 2.0f * _g;
+	    _g = g;
+            _a = 0.5f * (g - 1.0f);
+            da = (_a - a) / k;
+            u2 = true;
+	}
+
+        if (b != _b)
+	{
+            if      (b < 0.5f * _b) b = 0.5f * _b;
+            else if (b > 2.0f * _b) b = 2.0f * _b;
+            _b = b; 
+            u2 = true;
+	}
+
+        if (u2)
+	{
+            b *= 7 * f / sqrtf (g);         
+            _s2 = (1 - b) / (1 + b);
+            d2 = (_s2 - s2) / k;        
+	}
+
+        while (k--)
+	{  
+	    s1 += d1;
+	    s2 += d2;
+            a += da;
+            x = *sig;
+            y = x - s2 * _z2;
+            *sig++ -= a * (_z2 + s2 * y - x);                           
+            y -= s1 * _z1;
+            _z2 = _z1 + s1 * y;
+            _z1 = y + 1e-10f;
+	}
+    }
+    
+private:
+
+    float  _f, _b, _g;
+    float  _s1, _s2, _a;
+    float  _z1, _z2;
+};
+
+
+class Ladspa_Paramfilt : public LadspaPlugin
+{
+public:
+
+    enum { AIP, AOP, FILT, GAIN, SECT, NSECT = 4, NPORT = 20 };
+
+    Ladspa_Paramfilt (SampleRate fsam) : LadspaPlugin (fsam) {}
+    virtual void setport (PortIndex port, PortData *data);  
+    virtual void active  (bool act);  
+    virtual void runproc (SampleCount len, bool add);
+    virtual ~Ladspa_Paramfilt (void) {}  
+
+private:
+
+    float     *_port [NPORT];
+    float      _gain;
+    int        _fade;
+    Paramsect  _sect [NSECT];
+};
+
+
+#endif
diff --git a/src/filters_lv2.cc b/src/filters_lv2.cc
new file mode 100644
index 0000000..0696c38
--- /dev/null
+++ b/src/filters_lv2.cc
@@ -0,0 +1,56 @@
+/*
+  Copyright (C) 2012 David Robillard <d@drobilla.net>
+    
+  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., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include <stddef.h>
+
+#include "filters.h"
+#include "plugin_lv2.h"
+
+extern "C" {
+
+static LV2_Handle
+instantiate(const LV2_Descriptor*     descriptor,
+            double                    rate,
+            const char*               bundle_path,
+            const LV2_Feature* const* features)
+{
+	return new Ladspa_Paramfilt(rate);
+}
+
+static const LV2_Descriptor descriptor = {
+	"http://drobilla.net/plugins/fomp/parametric1",
+	instantiate,
+	connect_port,
+	activate,
+	run,
+	deactivate,
+	cleanup,
+	NULL
+};
+
+LV2_SYMBOL_EXPORT
+const LV2_Descriptor*
+lv2_descriptor(uint32_t index)
+{
+	switch (index) {
+	case 0:  return &descriptor;
+	default: return NULL;
+	}
+}
+
+}  // extern "C"
diff --git a/wscript b/wscript
index a2a35f7..042dbb8 100644
--- a/wscript
+++ b/wscript
@@ -73,9 +73,11 @@ def build(bld):
         LIB_EXT      = bld.env.pluginlib_EXT,
         install_path = '${LV2DIR}/fomp.lv2')
 
-    plugins = ['blvco',
+    plugins = ['autowah',
+               'blvco',
                'cs_chorus',
                'cs_phaser',
+               'filters',
                'mvchpf24',
                'mvclpf24']
     for i in plugins: