/home/marsyas/marsyas/src/marsyas/LPC.h

/*
** Copyright (C) 1998-2005 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.
*/


#ifndef MARSYAS_LPC_H
#define MARSYAS_LPC_H

#include "MarSystem.h"

namespace Marsyas
{
class LPC: public MarSystem
{
private: 
    void addControls();
    void myUpdate(MarControlPtr sender);

    MarControlPtr ctrl_coeffs_;
  MarControlPtr ctrl_power_;
  MarControlPtr ctrl_pitch_;
    mrs_natural order_;
    mrs_natural featureMode_;

    realvec Zs_;
    realvec temp_;
    
    void autocorrelationWarped(const realvec& in, realvec& r, mrs_real& pitch, mrs_real lambda);

    void LevinsonDurbin(const realvec& r, realvec& a, realvec& k, mrs_real& e);

    mrs_real predictionError(const realvec& data, const realvec& coeffs);

    /*implementation from peter Kabal
     *http://www-mmsp.ece.mcgill.ca/Documents/Software/index.html
     *
     * Returns the dot product of two vectors x1 and x2 of size N
     */
    mrs_real VRfDotProd (mrs_real * x1, mrs_real * x2, mrs_natural N);

     /* Computes the Nt (order+1) reflection coefficients cor from a time serie x of size Nx
     */
    void SPautoc (mrs_real * x, mrs_natural Nx, mrs_real * cor, mrs_natural Nt);

    /* Computes the Np autocorrelation coefficients pc [a(1) ... a(order)] from the reflections coefficients rxx
       and return the prediction error
     */
    mrs_real SPcorXpc (mrs_real * rxx, mrs_real * pc, mrs_natural Np);

public:
    LPC(std::string name);
    LPC(const LPC&);
    ~LPC();

    MarSystem* clone() const;  

    void myProcess(realvec& in, realvec& out);
};

}//namespace Marsyas

#endif

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