DCTReduce.h

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Tipic

    Centre for Digital Music, Queen Mary, University of London.

    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.  See the file
    COPYING included with this distribution for more information.
*/

#ifndef DCTREDUCE_H
#define DCTREDUCE_H

#include "dsp/transforms/DCT.h"

#include <vector>

class DCTReduce
{
public:
    DCTReduce(int size, int coefficientsToDrop) :
    m_size(size),
    m_dct(size),
    m_dctOut(size),
    m_coefficientsToDrop(coefficientsToDrop)
    { } 

    std::vector<double> process(std::vector<double> in) {
    std::vector<double> out(in.size());
    m_dct.forward(in.data(), m_dctOut.data());
    for (int i = 0; i < m_coefficientsToDrop && i < m_size; ++i) {
        m_dctOut[i] = 0.0;
    }
    m_dct.inverse(m_dctOut.data(), out.data());
    return out;
    }
    
private:
    int m_size;
    DCT m_dct;
    std::vector<double> m_dctOut;
    int m_coefficientsToDrop;
};

#endif