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Eq.cc

/*
      Eq.cc
      
      Copyright 2002-4 Tim Goetze <tim@quitte.de>
      
      http://quitte.de/dsp/

      10-band octave-spread equalizer.

*/
/*
      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., 59 Temple Place - Suite 330, Boston, MA
      02111-1307, USA or point your web browser to http://www.gnu.org.
*/

#include "basics.h"
#include <stdio.h>

#include "Eq.h"
#include "Descriptor.h"

void
Eq::init (double _fs)
{
      fs = _fs;
      eq.init (fs, 1.2);
      normal = NOISE_FLOOR;
}

inline static double 
adjust_gain (int i, double g)
{
      static float adjust[] = {
            0.69238604707174034, 0.67282771124180096, 
            0.67215187672467813, 0.65768648447259315, 
            0.65988083755898952, 0.66359580101701909, 
            0.66485139160960427, 0.65890297086039662, 
            0.6493229390740376, 0.82305724539749325
      };

      return g * adjust[i];
}

void
Eq::activate()
{
      for (int i = 0; i < 10; ++i)
      {
            gain[i] = *ports [1 + i];
            eq.gain[i] = adjust_gain (i, DSP::db2lin (gain[i]));
      }
}

template <sample_func_t F>
void
Eq::one_cycle (int frames)
{
      d_sample * s = ports[0];

      /* evaluate band gain changes and compute recursion factor to prevent
       * zipper noise */
      double one_over_n = 1. / frames;

      for (int i = 0; i < 10; ++i)
      {
            if (*ports [1 + i] == gain[i])
            {
                  /* no gain factoring */
                  eq.gf[i] = 1;
                  continue;
            }

            gain[i] = *ports [1 + i];

            double want = adjust_gain (i, DSP::db2lin (gain[i]));
            eq.gf[i] = pow (want / eq.gain[i], one_over_n);
      }

      d_sample * d = ports[11];

      for (int i = 0; i < frames; ++i)
            F (d, i, eq.process (s[i] + normal), adding_gain);

      normal = -normal;
}

/* //////////////////////////////////////////////////////////////////////// */

PortInfo
Eq::port_info [] =
{
      {
            "in",
            INPUT | AUDIO,
            {0, -1, 1}
      }, {
            "31 Hz",
            INPUT | CONTROL,
            {BOUNDED | DEFAULT_0, -48, 30}
      }, {
            "63 Hz",
            INPUT | CONTROL,
            {BOUNDED | DEFAULT_0, -48, 30}
      }, {
            "125 Hz",
            INPUT | CONTROL,
            {BOUNDED | DEFAULT_0, -48, 30}
      }, {
            "250 Hz",
            INPUT | CONTROL,
            {BOUNDED | DEFAULT_0, -48, 30}
      }, {
            "500 Hz",
            INPUT | CONTROL,
            {BOUNDED | DEFAULT_0, -48, 30}
      }, {
            "1 kHz",
            INPUT | CONTROL,
            {BOUNDED | DEFAULT_0, -48, 30}
      }, {
            "2 kHz",
            INPUT | CONTROL,
            {BOUNDED | DEFAULT_0, -48, 30}
      }, {
            "4 kHz",
            INPUT | CONTROL,
            {BOUNDED | DEFAULT_0, -48, 30}
      }, {
            "8 kHz",
            INPUT | CONTROL,
            {BOUNDED | DEFAULT_0, -48, 30}
      }, {
            "16 kHz",
            INPUT | CONTROL,
            {BOUNDED | DEFAULT_0, -48, 30}
      }, {
            "out",
            OUTPUT | AUDIO,
            {0}
      }
};

Descriptor<Eq>::Descriptor<Eq>()
{
      UniqueID = 1773;
      Label = "Eq";
      Properties = HARD_RT;

      Name = "10-band eq";
      Maker = "Tim Goetze <tim@quitte.de>";
      Copyright = "GPL, 2004";

      /* fill port info and vtable */
      autogen();
}


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