Marsyas  0.6.0-alpha
/usr/src/RPM/BUILD/marsyas-0.6.0/src/marsyas/marsystems/LPCC.cpp
Go to the documentation of this file.
00001 /*
00002 ** Copyright (C) 1998-2006 George Tzanetakis <gtzan@cs.uvic.ca>
00003 **
00004 ** This program is free software; you can redistribute it and/or modify
00005 ** it under the terms of the GNU General Public License as published by
00006 ** the Free Software Foundation; either version 2 of the License, or
00007 ** (at your option) any later version.
00008 **
00009 ** This program is distributed in the hope that it will be useful,
00010 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
00011 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00012 ** GNU General Public License for more details.
00013 **
00014 ** You should have received a copy of the GNU General Public License
00015 ** along with this program; if not, write to the Free Software
00016 ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
00017 */
00018 
00019 #include "LPCC.h"
00020 #include "../common_source.h"
00021 
00022 using std::ostringstream;
00023 using namespace Marsyas;
00024 
00025 LPCC::LPCC(mrs_string name):MarSystem("LPCC",name)
00026 {
00027   addControls();
00028 }
00029 
00030 LPCC::LPCC(const LPCC& a) : MarSystem(a)
00031 {
00032   ctrl_order_ = getctrl("mrs_natural/order");
00033 }
00034 
00035 LPCC::~LPCC()
00036 {
00037 }
00038 
00039 MarSystem*
00040 LPCC::clone() const
00041 {
00042   return new LPCC(*this);
00043 }
00044 
00045 void
00046 LPCC::addControls()
00047 {
00048   //read-only
00049   addctrl("mrs_natural/order", 1, ctrl_order_);
00050 }
00051 
00052 void
00053 LPCC::myUpdate(MarControlPtr sender)
00054 {
00055   (void) sender;  //suppress warning of unused parameter(s)
00056   MRSDIAG("LPCC.cpp - LPCC:myUpdate");
00057 
00058   ctrl_onSamples_->setValue(ctrl_inSamples_);
00059   ctrl_osrate_->setValue(ctrl_israte_, NOUPDATE);
00060 
00061   // output nr of observations (i.e. LPCC coefficients) is equal
00062   // to the number of LPC coefs (LPC coeffs - 1 pitch coeff - 1 power)
00063   mrs_natural order = ctrl_inObservations_->to<mrs_natural>() - 2;
00064   ctrl_order_->setValue(order, NOUPDATE);
00065   ctrl_onObservations_->setValue(order, NOUPDATE);
00066 
00067   //LPCC features names
00068   ostringstream oss;
00069   for (mrs_natural i = 0; i < ctrl_order_->to<mrs_natural>(); ++i)
00070     oss << "LPCC_" << i+1 << ",";
00071   ctrl_onObsNames_->setValue(oss.str(), NOUPDATE);
00072 
00073   tmp_.create(ctrl_onObservations_->to<mrs_natural>()+1, ctrl_onSamples_->to<mrs_natural>());
00074 }
00075 
00076 void
00077 LPCC::myProcess(realvec& in, realvec& out)
00078 {
00079   mrs_real sum;
00080   mrs_natural order = ctrl_order_->to<mrs_natural>();
00081 
00082 //************************************************************************
00083 // Based on:
00084 // http://www.mathworks.com/access/helpdesk/
00085 // help/toolbox/dspblks/index.html?/access/helpdesk/help/toolbox/dspblks/
00086 // lpctofromcepstralcoefficients.html
00087 //************************************************************************
00088   tmp_.setval(0.0);
00089   tmp_(0) = -log(in(order+1)); //[!][?]
00090   for (mrs_natural m = 1; m <= order; m++)
00091   {
00092     sum = 0.0;
00093     for (mrs_natural k=1; k <= m-1; k++)
00094       sum = sum + (mrs_real)(m-k) * in(k-1) * tmp_(m-k);
00095     tmp_(m) = +in(m-1) + sum / (mrs_real)m;
00096 
00097     out(m-1) = tmp_(m);//drop c0 => output only [c1 c2 c3 ... cp]
00098   }
00099 
00100   //MATLAB_PUT(in, "LPCC_in");
00101   //MATLAB_PUT(out, "LPCC_out");
00102   //MATLAB_EVAL("LPCC_test");
00103 }