SpectralExciter.cxx

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/*
 * Copyright (c) 2001-2004 MUSIC TECHNOLOGY GROUP (MTG)
 *                         UNIVERSITAT POMPEU FABRA
 *
 *
 * 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 "SpectralExciter.hxx"
#include "ProcessingFactory.hxx"

namespace CLAM
{
namespace Hidden
{
        static const char * metadata[] = {
                "key", "SpectralExciter",
        //      "category", "Spectral Transformations",
        //      "description", "SpectralExciter",
                0
        };
        static FactoryRegistrator<ProcessingFactory, SpectralExciter> reg = metadata;
}


bool SpectralExciter::Do(const Spectrum& in, Spectrum& out)
{
        out = in; //we are better off copying it no matter whether out has to be preserved or not.
                
        
        int spectrumSize = in.GetSize();
        TData spectralResolution = spectrumSize/in.GetSpectralRange();
        
        int highCutoff = Round(mHighCutoffFreqCtl.GetLastValue()* spectralResolution);

        TData threshold = log2lin(mThresholdCtl.GetLastValue());
        TData gain = log2lin(mHarmonicsGainCtl.GetLastValue());
        
        DataArray& outMag = out.GetMagBuffer();
        
        int i,n;
        
        //note: we might want to do something to the phase
        for(i = spectrumSize; i>highCutoff; i--)
        {
                if(outMag[i]>threshold) 
                {
                        for (n=i*2; n<spectrumSize; n+=i) {
                                outMag[n] += outMag[i]*gain;
                                if (outMag[n]>1.) {
                                        outMag[n]=1.;
                                }
                        }
                }
        }
        return true;
}


}