Add Zita reverb (stereo and ambisonic variant).

git-svn-id: http://svn.drobilla.net/lad/trunk/plugins/fomp.lv2@5395 a436a847-0d15-0410-975c-d299462d15a1

7 files changed, 1275 insertions, 0 deletions

diff --git a/src/pareq.cc b/src/pareq.cc
new file mode 100644
index 0000000..4feb991
--- /dev/null
+++ b/src/pareq.cc
@@ -0,0 +1,199 @@
+// ----------------------------------------------------------------------
+//
+//  Copyright (C) 2010-2013 Fons Adriaensen <fons@linuxaudio.org>
+//    
+//  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 "pareq.h"
+
+
+Pareq::Pareq (void) :
+    _touch0 (0),
+    _touch1 (0),
+    _state (BYPASS),
+    _g0 (1),
+    _g1 (1),
+    _f0 (1e3f),
+    _f1 (1e3f)
+{
+    setfsamp (0.0f);
+}
+
+
+Pareq::~Pareq (void)
+{
+}
+
+
+void Pareq::setfsamp (float fsamp)
+{
+    _fsamp = fsamp;
+    reset ();
+}
+
+
+void Pareq::reset (void)
+{
+    memset (_z1, 0, sizeof (float) * MAXCH); 
+    memset (_z2, 0, sizeof (float) * MAXCH); 
+}
+
+
+void Pareq::prepare (int nsamp)
+{
+    bool  upd = false;
+    float g, f;
+
+    if (_touch1 != _touch0)
+    {
+	if (_g0 <  0.1f) _g0 =  0.1f;
+	if (_g0 > 10.0f) _g0 = 10.0f;
+	if (_f0 < 20.0f) _f0 = 20.0f;
+	if (_f0 > 20e3f) _f0 = 20e3f;
+	g = _g0;
+	f = _f0;
+        if (g != _g1)
+	{
+	    upd = true;
+ 	    if      (g > 2 * _g1) _g1 *= 2;
+	    else if (_g1 > 2 * g) _g1 /= 2;
+	    else                  _g1 = g;
+	}
+        if (f != _f1)
+	{
+	    upd = true;
+ 	    if      (f > 2 * _f1) _f1 *= 2;
+	    else if (_f1 > 2 * f) _f1 /= 2;
+	    else                  _f1 = f;
+	}
+	if (upd) 
+	{
+	    if ((_state == BYPASS) && (_g1 == 1))
+	    {
+		calcpar1 (0, _g1, _f1);
+	    }
+	    else
+	    {
+		_state = SMOOTH;
+		calcpar1 (nsamp, _g1, _f1);
+	    }
+	}
+	else
+	{
+	    _touch1 = _touch0;
+            if (fabs (_g1 - 1) < 0.001f)
+            {
+	        _state = BYPASS;
+	        reset ();
+	    }
+  	    else    
+	    {
+	        _state = STATIC;
+	    }
+	}
+    }
+}
+
+
+void Pareq::calcpar1 (int nsamp, float g, float f)
+{
+    float b, c1, c2, gg;
+
+    f *= float (M_PI) / _fsamp;
+    b = 2 * f / sqrtf (g);         
+    gg = 0.5f * (g - 1);
+    c1 = -cosf (2 * f);
+    c2 = (1 - b) / (1 + b);
+    if (nsamp)
+    {
+	_dc1 = (c1 - _c1) / nsamp + 1e-30f;
+	_dc2 = (c2 - _c2) / nsamp + 1e-30f;
+	_dgg = (gg - _gg) / nsamp + 1e-30f;
+    }
+    else
+    {
+	_c1 = c1;
+	_c2 = c2;
+	_gg = gg;
+    }
+}
+
+
+void Pareq::process1 (int nsamp, int nchan, float *data[])
+{
+    int   i, j;
+    float c1, c2, gg;
+    float x, y, z1, z2;
+    float *p;
+
+    c1 = _c1;
+    c2 = _c2;
+    gg = _gg;
+    if (_state == SMOOTH)
+    {
+	for (i = 0; i < nchan; i++)
+	{
+	    p = data [i];
+            z1 = _z1 [i];
+            z2 = _z2 [i];
+            c1 = _c1;
+            c2 = _c2;
+            gg = _gg;
+            for (j = 0; j < nsamp; j++)
+            {
+                c1 += _dc1;
+                c2 += _dc2;
+                gg += _dgg;
+	        x = *p;
+	        y = x - c2 * z2;
+		*p++ = x - gg * (z2 + c2 * y - x);
+	        y -= c1 * z1;
+	        z2 = z1 + c1 * y;
+	        z1 = y + 1e-20f;
+	    }
+            _z1 [i] = z1;
+            _z2 [i] = z2;
+	}
+        _c1 = c1;
+        _c2 = c2;
+        _gg = gg;
+    }
+    else
+    {
+	for (i = 0; i < nchan; i++)
+	{
+	    p = data [i];
+            z1 = _z1 [i];
+            z2 = _z2 [i];
+            for (j = 0; j < nsamp; j++)
+            {
+	        x = *p;
+	        y = x - c2 * z2;
+		*p++ = x - gg * (z2 + c2 * y - x);
+	        y -= c1 * z1;
+	        z2 = z1 + c1 * y;
+	        z1 = y + 1e-20f;
+	    }
+            _z1 [i] = z1;
+            _z2 [i] = z2;
+	}
+    }
+}
+
diff --git a/src/pareq.h b/src/pareq.h
new file mode 100644
index 0000000..85ea7f9
--- /dev/null
+++ b/src/pareq.h
@@ -0,0 +1,75 @@
+// ----------------------------------------------------------------------
+//
+//  Copyright (C) 2010-2013 Fons Adriaensen <fons@linuxaudio.org>
+//    
+//  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 __PAREQ_H
+#define __PAREQ_H
+
+
+#include <stdint.h>
+#include <math.h>
+
+
+class Pareq
+{
+public:
+
+    Pareq (void);
+    ~Pareq (void);
+    
+    void setfsamp (float fsamp);
+    void setparam (float f, float g)
+    {
+	_f0 = f;
+	_g0 = powf (10.0f, 0.05f * g);
+	_touch0++;
+    }
+    void reset (void);
+    void prepare (int nsamp);
+    void process (int nsamp, int nchan, float *data[])
+    {
+	if (_state != BYPASS) process1 (nsamp, nchan, data);
+    }
+
+private:
+
+    enum { BYPASS, STATIC, SMOOTH, MAXCH = 4 };
+
+    void calcpar1 (int nsamp, float g, float f);
+    void process1 (int nsamp, int nchan, float *data[]);
+
+    volatile int16_t  _touch0;
+    volatile int16_t  _touch1;
+    bool              _bypass;
+    int               _state;
+    float             _fsamp;
+
+    float             _g0, _g1;
+    float             _f0, _f1;
+    float             _c1, _dc1;
+    float             _c2, _dc2;
+    float             _gg, _dgg;
+
+    float             _z1 [MAXCH];
+    float             _z2 [MAXCH];
+};
+
+
+#endif
diff --git a/src/reverbs.cc b/src/reverbs.cc
new file mode 100644
index 0000000..9e8e5af
--- /dev/null
+++ b/src/reverbs.cc
@@ -0,0 +1,125 @@
+// -----------------------------------------------------------------------
+//
+//  Copyright (C) 2003-2014 Fons Adriaensen <fons@linuxaudio.org>
+//    
+//  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 <stdio.h>
+#include <math.h>
+#include "reverbs.h"
+
+
+void Ladspa_zita_reverb::setport (PortIndex port, PortData *data)
+{
+	_port [port] = (float*)data;
+}
+
+
+void Ladspa_zita_reverb::active (bool act)
+{
+    if (! act)
+    {
+        _zreverb->reset ();
+	_nprep = 0;
+    }
+}
+
+
+void Ladspa_zita_reverb::runproc (SampleCount frames, bool add)
+{
+    unsigned long k;
+    float *inp [2] = { _port [A_INPL], _port [A_INPR] };
+    float *out [2] = { _port [A_OUTL], _port [A_OUTR] };
+
+    _zreverb->set_delay (_port [C_DELAY][0]);   
+    _zreverb->set_xover (_port [C_XOVER][0]);   
+    _zreverb->set_rtlow (_port [C_RTLOW][0]);   
+    _zreverb->set_rtmid (_port [C_RTMID][0]);   
+    _zreverb->set_fdamp (_port [C_FDAMP][0]);   
+    _zreverb->set_eq1 (_port [C_FREQ1][0], _port [C_GAIN1][0]);
+    _zreverb->set_eq2 (_port [C_FREQ2][0], _port [C_GAIN2][0]);
+    _zreverb->set_opmix (_port [C_OPMIX][0]);
+    while (frames)
+    {
+	if (!_nprep)
+	{
+	    _zreverb->prepare (FRAGM);
+	    _nprep = FRAGM;
+	}
+	k = (_nprep < frames) ? _nprep : frames;
+        _zreverb->process (k, inp, out);
+        inp [0] += k;
+        inp [1] += k;
+        out [0] += k;
+        out [1] += k;
+	frames -= k;
+	_nprep -= k;
+    }
+}
+
+
+
+void Ladspa_zita_reverb_amb::setport (PortIndex port, PortData *data)
+{
+	_port [port] = (float*)data;
+}
+
+
+void Ladspa_zita_reverb_amb::active (bool act)
+{
+    if (! act)
+    {
+        _zreverb->reset ();
+	_nprep = 0;
+    }
+}
+
+
+void Ladspa_zita_reverb_amb::runproc (SampleCount frames, bool add)
+{
+    unsigned long k;
+    float *inp [2] = { _port [A_INPL], _port [A_INPR] };
+    float *out [4] = { _port [A_OUTW], _port [A_OUTX], _port [A_OUTY], _port [A_OUTZ] };
+
+    _zreverb->set_delay (_port [C_DELAY][0]);   
+    _zreverb->set_xover (_port [C_XOVER][0]);   
+    _zreverb->set_rtlow (_port [C_RTLOW][0]);   
+    _zreverb->set_rtmid (_port [C_RTMID][0]);   
+    _zreverb->set_fdamp (_port [C_FDAMP][0]);   
+    _zreverb->set_eq1 (_port [C_FREQ1][0], _port [C_GAIN1][0]);
+    _zreverb->set_eq2 (_port [C_FREQ2][0], _port [C_GAIN2][0]);
+    _zreverb->set_rgxyz (_port [C_RGXYZ][0]);
+    while (frames)
+    {
+	if (!_nprep)
+	{
+	    _zreverb->prepare (FRAGM);
+	    _nprep = FRAGM;
+	}
+	k = (_nprep < frames) ? _nprep : frames;
+        _zreverb->process (k, inp, out);
+        inp [0] += k;
+        inp [1] += k;
+        out [0] += k;
+        out [1] += k;
+        out [2] += k;
+        out [3] += k;
+	frames -= k;
+	_nprep -= k;
+    }
+}
diff --git a/src/reverbs.h b/src/reverbs.h
new file mode 100644
index 0000000..2650856
--- /dev/null
+++ b/src/reverbs.h
@@ -0,0 +1,134 @@
+// -----------------------------------------------------------------------
+//
+//  Copyright (C) 2003-2014 Fons Adriaensen <fons@linuxaudio.org>
+//    
+//  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 __REVERBS_H
+#define __REVERBS_H
+
+#include "ladspaplugin.h"
+#include "zreverb.h"
+
+
+// -----------------------------------------------------------------------
+
+
+class Ladspa_zita_reverb : public LadspaPlugin
+{
+public:
+
+  enum
+  {
+      A_INPL,
+      A_INPR,
+      A_OUTL,
+      A_OUTR,
+      C_DELAY,
+      C_XOVER,
+      C_RTLOW,
+      C_RTMID,
+      C_FDAMP,
+      C_FREQ1,
+      C_GAIN1,
+      C_FREQ2,
+      C_GAIN2,
+      C_OPMIX,
+      NPORT
+  };
+
+  Ladspa_zita_reverb (SampleRate fsam) : LadspaPlugin (fsam)
+  {
+      _zreverb = new Zreverb ();
+      _zreverb->init (fsam, false);
+      _nprep = 0;
+  }
+  virtual void setport (PortIndex port, PortData *data);  
+  virtual void active  (bool act);  
+  virtual void runproc (SampleCount len, bool add);
+  virtual ~Ladspa_zita_reverb (void)
+  {
+      delete _zreverb;
+  }  
+
+private:
+
+  enum { FRAGM = 2048 };
+
+  float          *_port [NPORT];
+  Zreverb        *_zreverb;
+  unsigned long   _nprep;
+};
+
+
+// -----------------------------------------------------------------------
+
+
+class Ladspa_zita_reverb_amb : public LadspaPlugin
+{
+public:
+
+  enum
+  {
+      A_INPL,
+      A_INPR,
+      A_OUTW,
+      A_OUTX,
+      A_OUTY,
+      A_OUTZ,
+      C_DELAY,
+      C_XOVER,
+      C_RTLOW,
+      C_RTMID,
+      C_FDAMP,
+      C_FREQ1,
+      C_GAIN1,
+      C_FREQ2,
+      C_GAIN2,
+      C_RGXYZ,
+      NPORT
+  };
+
+  Ladspa_zita_reverb_amb (unsigned long fsam) : LadspaPlugin (fsam)
+  {
+      _zreverb = new Zreverb ();
+      _zreverb->init (fsam, true);
+      _nprep = 0;
+  }
+  virtual void setport (PortIndex port, PortData *data);  
+  virtual void active  (bool act);  
+  virtual void runproc (SampleCount len, bool add);
+  virtual ~Ladspa_zita_reverb_amb (void)
+  {
+      delete _zreverb;
+  }  
+
+private:
+
+  enum { FRAGM = 2048 };
+
+  float          *_port [NPORT];
+  Zreverb        *_zreverb;
+  unsigned long   _nprep;
+};
+
+
+// -----------------------------------------------------------------------
+
+
+#endif
diff --git a/src/reverbs_lv2.cc b/src/reverbs_lv2.cc
new file mode 100644
index 0000000..e6eb9f0
--- /dev/null
+++ b/src/reverbs_lv2.cc
@@ -0,0 +1,73 @@
+/*
+  Copyright (C) 2014 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 "reverbs.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_zita_reverb(rate);
+}
+
+static LV2_Handle
+instantiate_amb(const LV2_Descriptor*     descriptor,
+                double                    rate,
+                const char*               bundle_path,
+                const LV2_Feature* const* features)
+{
+	return new Ladspa_zita_reverb_amb(rate);
+}
+
+static const LV2_Descriptor descriptors[] = {
+	{
+		"http://drobilla.net/plugins/fomp/reverb",
+		instantiate,
+		connect_port,
+		activate,
+		run,
+		deactivate,
+		cleanup,
+		NULL
+	} , {
+		"http://drobilla.net/plugins/fomp/reverb_amb",
+		instantiate_amb,
+		connect_port,
+		activate,
+		run,
+		deactivate,
+		cleanup,
+		NULL
+	}
+};
+
+LV2_SYMBOL_EXPORT
+const LV2_Descriptor*
+lv2_descriptor(uint32_t index)
+{
+	return (index < 2) ? &descriptors[index] : NULL;
+}
+
+}  // extern "C"
diff --git a/src/zreverb.cc b/src/zreverb.cc
new file mode 100644
index 0000000..98055a2
--- /dev/null
+++ b/src/zreverb.cc
@@ -0,0 +1,425 @@
+// -----------------------------------------------------------------------
+//
+//  Copyright (C) 2003-2013 Fons Adriaensen <fons@linuxaudio.org>
+//    
+//  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 <stdio.h>
+#include <string.h>
+#include <math.h>
+#include "zreverb.h"
+
+
+// -----------------------------------------------------------------------
+
+
+Diff1::Diff1 (void) :
+    _size (0),
+    _line (0)
+{
+}    
+
+
+Diff1::~Diff1 (void)
+{
+    fini ();
+}
+
+
+void Diff1::init (int size, float c)
+{
+    _size = size;
+    _line = new float [size];
+    _c = c;
+    reset ();
+}
+
+
+void Diff1::fini (void)
+{
+    delete[] _line;
+    _size = 0;
+    _line = 0;
+}
+
+
+void Diff1::reset (void)
+{
+    memset (_line, 0, _size * sizeof (float));
+    _i = 0;
+}
+
+
+// -----------------------------------------------------------------------
+
+
+Delay::Delay (void) :
+    _size (0),
+    _line (0)
+{
+}
+
+
+Delay::~Delay (void)
+{
+    fini ();
+}
+
+
+void Delay::init (int size)
+{
+    _size = size;
+    _line = new float [size];
+    reset ();
+}
+
+
+void Delay::fini (void)
+{
+    delete[] _line;
+    _size = 0;
+    _line = 0;
+}
+
+
+void Delay::reset (void)
+{
+    memset (_line, 0, _size * sizeof (float));
+    _i = 0;
+}
+
+
+// -----------------------------------------------------------------------
+
+
+Vdelay::Vdelay (void) :
+    _size (0),
+    _line (0)
+{
+}
+
+
+Vdelay::~Vdelay (void)
+{
+    fini ();
+}
+
+
+void Vdelay::init (int size)
+{
+    _size = size;
+    _line = new float [size];
+    reset ();
+}
+
+
+void Vdelay::fini (void)
+{
+    delete[] _line;
+    _size = 0;
+    _line = 0;
+}
+
+
+void Vdelay::reset (void)
+{
+    memset (_line, 0, _size * sizeof (float));
+    _iwr = 0;
+    _ir0 = 0;
+    _ir1 = 0;
+}
+
+
+void Vdelay::set_delay (int del)
+{
+    _ir1 = _iwr - del;
+    if (_ir1 < 0) _ir1 += _size;
+}
+
+
+// -----------------------------------------------------------------------
+
+
+void Filt1::set_params (float del, float tmf, float tlo, float wlo, float thi, float chi)
+{
+    float g, t;
+
+    _gmf = powf (0.001f, del / tmf);
+    _glo = powf (0.001f, del / tlo) / _gmf - 1.0f;
+    _wlo = wlo;    
+    g = powf (0.001f, del / thi) / _gmf;
+    t = (1 - g * g) / (2 * g * g * chi);
+    _whi = (sqrtf (1 + 4 * t) - 1) / (2 * t); 
+} 
+
+ 
+// -----------------------------------------------------------------------
+
+
+float Zreverb::_tdiff1 [8] = 
+{
+    20346e-6f,
+    24421e-6f,
+    31604e-6f,
+    27333e-6f,
+    22904e-6f,
+    29291e-6f,
+    13458e-6f,
+    19123e-6f
+};
+
+
+float Zreverb::_tdelay [8] = 
+{
+   153129e-6f,
+   210389e-6f,
+   127837e-6f,
+   256891e-6f,
+   174713e-6f,
+   192303e-6f,
+   125000e-6f,
+   219991e-6f
+};
+
+
+Zreverb::Zreverb (void)
+{
+}
+
+
+Zreverb::~Zreverb (void)
+{
+    fini ();
+}
+
+
+void Zreverb::init (float fsamp, bool ambis)
+{
+    int i, k1, k2;
+
+    _fsamp = fsamp;
+    _ambis = ambis;
+    _cntA1 = 1;
+    _cntA2 = 0;
+    _cntB1 = 1;
+    _cntB2 = 0;
+    _cntC1 = 1;
+    _cntC2 = 0;
+
+    _ipdel = 0.04f;
+    _xover = 200.0f;
+    _rtlow = 3.0f;
+    _rtmid = 2.0f;
+    _fdamp = 3e3f;
+    _opmix = 1.0f;
+    _rgxyz = 0.0f;
+
+    _g0 = _d0 = 0;
+    _g1 = _d1 = 0;
+
+    _vdelay0.init ((int)(0.1f * _fsamp));
+    _vdelay1.init ((int)(0.1f * _fsamp));
+    for (i = 0; i < 8; i++)
+    {
+	k1 = (int)(floorf (_tdiff1 [i] * _fsamp + 0.5f));
+	k2 = (int)(floorf (_tdelay [i] * _fsamp + 0.5f));
+        _diff1 [i].init (k1, (i & 1) ? -0.6f : 0.6f);
+        _delay [i].init (k2 - k1);
+    }
+
+    _pareq1.setfsamp (fsamp);
+    _pareq2.setfsamp (fsamp);
+}
+
+
+void Zreverb::fini (void)
+{
+}
+
+
+void Zreverb::reset (void)
+{
+    int i;
+
+    _vdelay0.reset ();
+    _vdelay1.reset ();
+    for (i = 0; i < 8; i++)
+    {
+        _diff1 [i].reset ();
+        _filt1 [i].reset ();
+	_delay [i].reset ();
+    }
+}
+
+
+void Zreverb::prepare (int nfram)
+{
+    int    a, b, c, i, k;
+    float  t0, t1, wlo, chi;
+
+    a = _cntA1;
+    b = _cntB1;
+    c = _cntC1;
+    _d0 = _d1 = 0;
+
+    if (a != _cntA2)
+    {
+	if (_ipdel < 0.02f) _ipdel = 0.02f;
+	if (_ipdel > 0.10f) _ipdel = 0.10f;
+        k = (int)(floorf ((_ipdel - 0.02f) * _fsamp + 0.5f));
+        _vdelay0.set_delay (k);
+        _vdelay1.set_delay (k);
+        _cntA2 = a;
+    }
+
+    if (b != _cntB2)
+    {
+	if (_xover < 50.0f)  _xover = 50.0f;
+	if (_xover > 1.0e3f) _xover = 1.0e3f;
+	if (_rtlow < 1.0f) _rtlow = 1.0f;
+	if (_rtlow > 8.0f) _rtlow = 8.0f;
+	if (_rtmid < 1.0f) _rtmid = 1.0f;
+	if (_rtmid > 8.0f) _rtmid = 8.0f;
+	if (_fdamp <  1.5e3f) _fdamp =  1.5e3f;
+	if (_fdamp > 24.0e3f) _fdamp = 24.0e3f;
+         wlo = 6.2832f * _xover / _fsamp;
+	 if (_fdamp > 0.49f * _fsamp) chi = 2;
+	 else chi = 1 - cosf (6.2832f * _fdamp / _fsamp);
+         for (i = 0; i < 8; i++)
+	 {
+             _filt1 [i].set_params (_tdelay [i], _rtmid, _rtlow, wlo, 0.5f * _rtmid, chi);
+	 }
+         _cntB2 = b;
+    }
+
+    if (c != _cntC2)
+    {
+        if (_rtmid < 1.0f) _rtmid = 1.0f;
+        if (_rtmid > 8.0f) _rtmid = 8.0f;
+	if (_ambis)
+	{
+	    if (_rgxyz < -9.0f) _rgxyz = -9.0f;
+	    if (_rgxyz >  9.0f) _rgxyz =  9.0f;
+	    t0 = 1.0f / sqrtf (_rtmid);
+	    t1 = t0 * powf (10.0f, 0.05f * _rgxyz);
+	}
+	else
+	{
+	    if (_opmix < 0.0f) _opmix = 0.0f;
+	    if (_opmix > 1.0f) _opmix = 1.0f;
+	    t0 = (1 - _opmix) * (1 + _opmix);
+	    t1 = 0.7f * _opmix * (2 - _opmix) / sqrtf (_rtmid);
+	}
+        _d0 = (t0 - _g0) / nfram;
+        _d1 = (t1 - _g1) / nfram;
+        _cntC2 = c;
+    }
+
+    _pareq1.prepare (nfram);
+    _pareq2.prepare (nfram);
+}
+
+
+void Zreverb::process (int nfram, float *inp [], float *out [])
+{	
+    int   i, n;
+    float *p0, *p1;
+    float *q0, *q1, *q2, *q3;
+    float t, g, x0, x1, x2, x3, x4, x5, x6, x7;
+
+    g = sqrtf (0.125f);
+
+    p0 = inp [0];
+    p1 = inp [1];
+    q0 = out [0];
+    q1 = out [1];
+    q2 = out [2];
+    q3 = out [3];
+
+    for (i = 0; i < nfram; i++)
+    {
+	_vdelay0.write (p0 [i]);
+	_vdelay1.write (p1 [i]);
+
+ 	t = 0.3f * _vdelay0.read1 ();
+	x0 = _diff1 [0].process (_delay [0].read () + t);
+	x1 = _diff1 [1].process (_delay [1].read () + t);
+	x2 = _diff1 [2].process (_delay [2].read () - t);
+	x3 = _diff1 [3].process (_delay [3].read () - t);
+ 	t = 0.3f * _vdelay1.read1 ();
+	x4 = _diff1 [4].process (_delay [4].read () + t);
+	x5 = _diff1 [5].process (_delay [5].read () + t);
+	x6 = _diff1 [6].process (_delay [6].read () - t);
+	x7 = _diff1 [7].process (_delay [7].read () - t);
+
+        t = x0 - x1; x0 += x1;  x1 = t;
+        t = x2 - x3; x2 += x3;  x3 = t;
+        t = x4 - x5; x4 += x5;  x5 = t;
+        t = x6 - x7; x6 += x7;  x7 = t;
+        t = x0 - x2; x0 += x2;  x2 = t;
+        t = x1 - x3; x1 += x3;  x3 = t;
+        t = x4 - x6; x4 += x6;  x6 = t;
+        t = x5 - x7; x5 += x7;  x7 = t;
+        t = x0 - x4; x0 += x4;  x4 = t;
+        t = x1 - x5; x1 += x5;  x5 = t;
+        t = x2 - x6; x2 += x6;  x6 = t;
+        t = x3 - x7; x3 += x7;  x7 = t;
+
+	if (_ambis)
+	{
+            _g0 += _d0;
+            _g1 += _d1;
+	    q0 [i] = _g0 * x0;
+	    q1 [i] = _g1 * x1;
+	    q2 [i] = _g1 * x4;
+	    q3 [i] = _g1 * x2;
+	}
+	else
+	{
+            _g1 += _d1;
+	    q0 [i] = _g1 * (x1 + x2);
+	    q1 [i] = _g1 * (x1 - x2);
+	}
+
+	_delay [0].write (_filt1 [0].process (g * x0));
+	_delay [1].write (_filt1 [1].process (g * x1));
+	_delay [2].write (_filt1 [2].process (g * x2));
+        _delay [3].write (_filt1 [3].process (g * x3));
+        _delay [4].write (_filt1 [4].process (g * x4));
+        _delay [5].write (_filt1 [5].process (g * x5));
+        _delay [6].write (_filt1 [6].process (g * x6));
+        _delay [7].write (_filt1 [7].process (g * x7));
+    }
+
+    n = _ambis ? 4 : 2;
+    _pareq1.process (nfram, n, out);
+    _pareq2.process (nfram, n, out);
+    if (!_ambis)
+    {
+	for (i = 0; i < nfram; i++)
+	{
+	    _g0 += _d0;
+	    q0 [i] += _g0 * _vdelay0.read0 ();
+	    q1 [i] += _g0 * _vdelay1.read0 ();
+	}
+    }
+}
+
+
+// -----------------------------------------------------------------------
+
diff --git a/src/zreverb.h b/src/zreverb.h
new file mode 100644
index 0000000..2f9b905
--- /dev/null
+++ b/src/zreverb.h
@@ -0,0 +1,244 @@
+// -----------------------------------------------------------------------
+//
+//  Copyright (C) 2003-2013 Fons Adriaensen <fons@linuxaudio.org>
+//    
+//  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 __ZREVERB_H
+#define __ZREVERB_H
+
+#include "pareq.h"
+
+
+// -----------------------------------------------------------------------
+
+
+class Diff1
+{
+private:
+
+    friend class Zreverb;
+    
+    Diff1 (void);
+    ~Diff1 (void);
+
+    void  init (int size, float c);
+    void  fini (void);
+    void  reset (void);
+
+    float process (float x)
+    {
+	float z = _line [_i];
+	x -= _c * z;
+        _line [_i] = x;
+        if (++_i == _size) _i = 0;
+	return z + _c * x;
+    } 
+
+    int     _i;
+    float   _c;
+    int     _size;
+    float  *_line;
+};
+
+
+// -----------------------------------------------------------------------
+
+
+class Filt1
+{
+private:
+
+    friend class Zreverb;
+    
+    Filt1 (void) : _slo (0), _shi (0) {}
+    ~Filt1 (void) {}
+
+    void  set_params (float del, float tmf, float tlo, float wlo, float thi, float chi);
+
+    float process (float x)
+    {
+        _slo += _wlo * (x - _slo) + 1e-10f;
+        x += _glo * _slo;
+        _shi += _whi * (x - _shi);
+	return _gmf * _shi;
+    }
+
+    void reset (void)
+    {
+	_slo = 0;
+	_shi = 0;
+    }
+
+    float   _gmf;
+    float   _glo;
+    float   _wlo;
+    float   _whi;
+    float   _slo;
+    float   _shi;    
+};
+
+
+
+
+// -----------------------------------------------------------------------
+
+
+class Delay
+{
+private:
+
+    friend class Zreverb;
+    
+    Delay (void);
+    ~Delay (void);
+
+    void  init (int size);
+    void  fini (void);
+    void  reset (void);
+
+    float read (void)
+    {
+	return _line [_i];
+    }
+
+    void write (float x)
+    {
+	_line [_i++] = x;
+	if (_i == _size) _i = 0;
+    }
+
+    int     _i;
+    int     _size;
+    float  *_line;
+};
+
+
+// -----------------------------------------------------------------------
+
+
+class Vdelay
+{
+private:
+
+    friend class Zreverb;
+    
+    Vdelay (void);
+    ~Vdelay (void);
+
+    void  init (int size);
+    void  fini (void);
+    void  reset (void);
+    void  set_delay (int del);
+
+    void write (float x)
+    {
+	_line [_iwr++] = x;
+	if (_iwr == _size) _iwr = 0;
+    }
+
+    float read0 (void)
+    {
+	float x = _line [_ir0++];
+	if (_ir0 == _size) _ir0 = 0;
+	return x;
+    }
+
+    float read1 (void)
+    {
+	float x = _line [_ir1++];
+	if (_ir1 == _size) _ir1 = 0;
+	return x;
+    }
+
+    int     _iwr;
+    int     _ir0;
+    int     _ir1;
+    int     _size;
+    float  *_line;
+};
+
+
+// -----------------------------------------------------------------------
+
+
+class Zreverb
+{
+public:
+
+    Zreverb (void);
+    ~Zreverb (void);
+
+    void init (float fsamp, bool ambis);
+    void fini (void);
+
+    void reset (void);
+    void prepare (int n);
+    void process (int n, float *inp [], float *out []);
+
+    void set_delay (float v) { _ipdel = v; _cntA1++; }
+    void set_xover (float v) { _xover = v; _cntB1++; }
+    void set_rtlow (float v) { _rtlow = v; _cntB1++; }
+    void set_rtmid (float v) { _rtmid = v; _cntB1++; _cntC1++; }
+    void set_fdamp (float v) { _fdamp = v; _cntB1++; }
+    void set_opmix (float v) { _opmix = v; _cntC1++; }
+    void set_rgxyz (float v) { _rgxyz = v; _cntC1++; }
+    void set_eq1 (float f, float g) { _pareq1.setparam (f, g); }
+    void set_eq2 (float f, float g) { _pareq2.setparam (f, g); }
+
+private:
+
+
+    float   _fsamp;
+    bool    _ambis;
+
+    Vdelay  _vdelay0;
+    Vdelay  _vdelay1;
+    Diff1   _diff1 [8];
+    Filt1   _filt1 [8];
+    Delay   _delay [8];
+    
+    volatile int _cntA1;
+    volatile int _cntB1;
+    volatile int _cntC1;
+    int     _cntA2;
+    int     _cntB2;
+    int     _cntC2;
+    float   _ipdel;
+    float   _xover;
+    float   _rtlow;
+    float   _rtmid;
+    float   _fdamp;
+    float   _opmix;
+    float   _rgxyz;
+
+    float   _g0, _d0;
+    float   _g1, _d1;
+
+    Pareq   _pareq1;
+    Pareq   _pareq2;
+
+    static float _tdiff1 [8];
+    static float _tdelay [8];
+};
+
+
+// -----------------------------------------------------------------------
+
+
+#endif