Vocoder.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 "Vocoder.hxx"
#include "ProcessingFactory.hxx"

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

bool Vocoder::Do(const Spectrum& in, Spectrum& out)
{
        if ( !mConfig.GetPreserveOuts() )
        {
                out = in; //TODO big cludge for streaming
        }
        
        int nBands = mNumBandsCtl.GetLastValue(); 
        int nGainBands = 5; //it is one more than the actual gains
        int firstBand = 5;
        TData fFirstBand = 100;
        
        DataArray gains(4);
        gains[0] = log2lin(mBand0GainCtl.GetLastValue());
        gains[1] = log2lin(mBand1GainCtl.GetLastValue());
        gains[2] = log2lin(mBand2GainCtl.GetLastValue());
        gains[3] = log2lin(mBand3GainCtl.GetLastValue());
        
        int spectrumSize = in.GetSize();
        TData spectralRange = in.GetSpectralRange();
        TData spectralResolution = spectrumSize/spectralRange;
        
        mMagBuffer.Resize(0);// make sure all bins are set to zero
        mMagBuffer.Resize(spectrumSize);
        mMagBuffer.SetSize(spectrumSize);
        
        TData bandFactor = pow(TData(spectrumSize),1./nBands);
        TData fBandFactor = pow(TData(spectralRange),1./nBands);
        
        TData fCurrentBandLimit = fFirstBand;
        int currentBandLimit = Round(fFirstBand*spectralResolution);
        int lastBandLimit = 0;
        TData fLastBandLimit = 0.;
        
        int freqShift = Round(mFreqShiftCtl.GetLastValue()*spectralResolution); 
        
        int currentOscBin = int(spectrumSize/nBands) + freqShift;
        TData fCurrentOsc = spectralRange/nBands;
        
        int currentGainIndex = 0;
        TData fCurrentGainBandLimit = fCurrentBandLimit*2;
        int currentGainBandLimit = Round(fCurrentGainBandLimit*spectralResolution);
        
        TData gainBandFactor = pow(TData(spectrumSize/currentBandLimit),1./nGainBands);
        TData fGainBandFactor = pow(TData(spectralRange/fCurrentGainBandLimit),1./nGainBands);
        
        TData bandEnergy =0;
        DataArray& inMag = in.GetMagBuffer();
        int currentBand = 0;
        for(int i = 0; i<spectrumSize; i++)
        {
                if(i>currentBandLimit)
                {
                        bandEnergy = sqrt(bandEnergy);
                        mMagBuffer[currentOscBin] = bandEnergy*gains[currentGainIndex];
                        lastBandLimit = currentBandLimit;
                        fCurrentBandLimit*=fBandFactor;
                        currentBandLimit = Round(fCurrentBandLimit*spectralResolution);
                        if(currentBandLimit>spectrumSize) currentBandLimit = spectrumSize;
                        currentOscBin =  int ((currentBandLimit-lastBandLimit)*0.5 + lastBandLimit) + freqShift;
                        bandEnergy = 0;
                        currentBand++;
                        if(currentBand>nBands) break;
                }
                if (i>currentGainBandLimit)
                { 
                        if(currentGainIndex<3)
                                currentGainIndex++;
                        fCurrentGainBandLimit*=fGainBandFactor;
                        currentGainBandLimit = Round(fCurrentGainBandLimit*spectralResolution);
                }
                bandEnergy += inMag[i];
                
        }
        out.SetMagBuffer(mMagBuffer);
        return true;
}


}