/home/marsyas/marsyas/src/marsyas/TimeStretch.cpp

/*
** Copyright (C) 1998-2006 George Tzanetakis <gtzan@cs.uvic.ca>
**  
** 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.
*/

#include "TimeStretch.h"

using namespace std;
using namespace Marsyas;

TimeStretch::TimeStretch(mrs_string name):MarSystem("TimeStretch",name)
{
  //type_ = "TimeStretch";
  //name_ = name;

    addControls();
}

TimeStretch::~TimeStretch()
{
}

MarSystem* 
TimeStretch::clone() const 
{
  return new TimeStretch(*this);
}

void 
TimeStretch::addControls()
{
  addctrl("mrs_real/factor", 1.0);
}

void 
TimeStretch::myProcess(realvec& in, realvec& out)
{
  //checkFlow(in,out);
  mrs_real factor = getctrl("mrs_real/factor")->to<mrs_real>();
  mrs_natural inSamples = getctrl("mrs_natural/inSamples")->to<mrs_natural>();
  
  for (mrs_natural t=0; t < inSamples; t++)
    {
      // linear interpolation 
      ni = t* factor;
      li = ((unsigned long)ni) % inSamples;
      ri = li + 1;
      
      w_ = ni - li;
      if (ri < inSamples) 
          out(0,t) = in(li) + w_ * (in(0,ri) - in(0,li));
      else 
          out(0,t) = in(li);
    }
}






    

    

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