3BandCompressor.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 "3BandCompressor.hxx"
#include "ProcessingFactory.hxx"

namespace CLAM
{

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

bool ThreeBandCompressor::Do(const Spectrum& in, Spectrum& out)
{
        out = in; //even if out needs to be preserved, we need to copy content
        
        DataArray& oMag = out.GetMagBuffer();
        const DataArray& iMag = in.GetMagBuffer();
        
        int spectrumSize = in.GetSize();
        
        TData spectralResolution = spectrumSize/in.GetSpectralRange();
        
        int lowCutoff = Round(mLowCutoffFreqCtl.GetLastValue()* spectralResolution);
        int highCutoff =        Round(mHighCutoffFreqCtl.GetLastValue()* spectralResolution);

        //note: control is supposed to be sent as dB's
        TData lowThreshold =    log2lin(mLowThresholdCtl.GetLastValue());
        TData midThreshold =    log2lin(mMidThresholdCtl.GetLastValue());
        TData highThreshold =   log2lin(mHighThresholdCtl.GetLastValue());
        
        TData currentThreshold = lowThreshold;
        for(int i = 0; i<lowCutoff; i++)
        {
                if(iMag[i]>lowThreshold)
                        oMag[i] = lowThreshold;
        }
        for(int i = lowCutoff; i<highCutoff; i++)
        {
                if(iMag[i]>midThreshold)
                        oMag[i] = midThreshold;
        }
        for(int i = highCutoff; i<spectrumSize; i++)
        {
                if(iMag[i]>highThreshold)
                        oMag[i] = highThreshold;
        }
        return true;
}


}