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/* BSE - Better Sound Engine
* Copyright (C) 2006 Tim Janik
*
* This software is provided "as is"; redistribution and modification
* is permitted, provided that the following disclaimer is retained.
*
* This software 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.
* In no event shall the authors or contributors be liable for any
* direct, indirect, incidental, special, exemplary, or consequential
* damages (including, but not limited to, procurement of substitute
* goods or services; loss of use, data, or profits; or business
* interruption) however caused and on any theory of liability, whether
* in contract, strict liability, or tort (including negligence or
* otherwise) arising in any way out of the use of this software, even
* if advised of the possibility of such damage.
*/
#include "bsefilter.h"
#include <birnet/birnet.hh>
using namespace Birnet;
extern "C" {
const gchar*
bse_iir_filter_kind_string (BseIIRFilterKind fkind)
{
switch (fkind)
{
case BSE_IIR_FILTER_BUTTERWORTH: return "Butterworth";
case BSE_IIR_FILTER_BESSEL: return "Bessel";
case BSE_IIR_FILTER_CHEBYSHEV1: return "Chebyshev1";
case BSE_IIR_FILTER_CHEBYSHEV2: return "Chebyshev2";
case BSE_IIR_FILTER_ELLIPTIC: return "Elliptic";
default: return "?unknown?";
}
}
const gchar*
bse_iir_filter_type_string (BseIIRFilterType ftype)
{
switch (ftype)
{
case BSE_IIR_FILTER_LOW_PASS: return "Low-pass";
case BSE_IIR_FILTER_BAND_PASS: return "Band-pass";
case BSE_IIR_FILTER_HIGH_PASS: return "High-pass";
case BSE_IIR_FILTER_BAND_STOP: return "Band-stop";
default: return "?unknown?";
}
}
gchar*
bse_iir_filter_request_string (const BseIIRFilterRequest *ifr)
{
String s;
s += bse_iir_filter_kind_string (ifr->kind);
s += " ";
s += bse_iir_filter_type_string (ifr->type);
s += " order=" + string_from_int (ifr->order);
s += " sample-rate=" + string_from_float (ifr->sampling_frequency);
if (ifr->kind == BSE_IIR_FILTER_CHEBYSHEV1 || ifr->kind == BSE_IIR_FILTER_ELLIPTIC)
s += " passband-ripple-db=" + string_from_float (ifr->passband_ripple_db);
s += " passband-edge=" + string_from_float (ifr->passband_edge);
if (ifr->type == BSE_IIR_FILTER_BAND_PASS || ifr->type == BSE_IIR_FILTER_BAND_STOP)
s += " passband-edge2=" + string_from_float (ifr->passband_edge2);
if (ifr->kind == BSE_IIR_FILTER_ELLIPTIC && ifr->stopband_db < 0)
s += " stopband-db=" + string_from_float (ifr->stopband_db);
if (ifr->kind == BSE_IIR_FILTER_ELLIPTIC && ifr->stopband_edge > 0)
s += " stopband-edge=" + string_from_float (ifr->stopband_edge);
return g_strdup (s.c_str());
}
gchar*
bse_iir_filter_design_string (const BseIIRFilterDesign *fid)
{
String s;
s += "order=" + string_from_int (fid->order);
s += " sampling-frequency=" + string_from_float (fid->sampling_frequency);
s += " center-frequency=" + string_from_float (fid->center_frequency);
s += " gain=" + string_from_double (fid->gain);
s += " n_zeros=" + string_from_int (fid->n_zeros);
s += " n_poles=" + string_from_int (fid->n_poles);
for (uint i = 0; i < fid->n_zeros; i++)
{
String u ("Zero:");
u += " " + string_from_double (fid->zz[i].re);
u += " + " + string_from_double (fid->zz[i].im) + "*i";
s += "\n" + u;
}
for (uint i = 0; i < fid->n_poles; i++)
{
String u ("Pole:");
u += " " + string_from_double (fid->zp[i].re);
u += " + " + string_from_double (fid->zp[i].im) + "*i";
s += "\n" + u;
}
String u;
#if 0
uint o = fid->order;
u = string_from_double (fid->zn[o]);
while (o--)
u = "(" + u + ") * z + " + string_from_double (fid->zn[o]);
s += "\nNominator: " + u;
o = fid->order;
u = string_from_double (fid->zd[o]);
while (o--)
u = "(" + u + ") * z + " + string_from_double (fid->zd[o]);
s += "\nDenominator: " + u;
#endif
return g_strdup (s.c_str());
}
bool
bse_iir_filter_design (const BseIIRFilterRequest *filter_request,
BseIIRFilterDesign *filter_design)
{
if (filter_request->kind == BSE_IIR_FILTER_BUTTERWORTH ||
filter_request->kind == BSE_IIR_FILTER_CHEBYSHEV1 ||
filter_request->kind == BSE_IIR_FILTER_ELLIPTIC)
return _bse_filter_design_ellf (filter_request, filter_design);
return false;
}
} // C
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