view dsp/rateconversion/Decimator.cpp @ 209:ccd2019190bf msvc

Some MSVC fixes, including (temporarily, probably) renaming the FFT source file to avoid getting it mixed up with the Vamp SDK one in our object dir
author Chris Cannam
date Thu, 01 Feb 2018 16:34:08 +0000
parents 4f092806782b
children fdaa63607c15
line wrap: on
line source
/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    QM DSP Library

    Centre for Digital Music, Queen Mary, University of London.
    This file 2005-2006 Christian Landone.

    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.
*/

#include "Decimator.h"

#include <iostream>

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

Decimator::Decimator( unsigned int inLength, unsigned int decFactor )
{

    m_inputLength = 0;
    m_outputLength = 0;
    m_decFactor = 1;

    initialise( inLength, decFactor );
}

Decimator::~Decimator()
{
    deInitialise();
}

void Decimator::initialise( unsigned int inLength, unsigned int decFactor)
{
    m_inputLength = inLength;
    m_decFactor = decFactor;
    m_outputLength = m_inputLength / m_decFactor;

    decBuffer = new double[ m_inputLength ];

    // If adding new factors here, add them to
    // getHighestSupportedFactor in the header as well

    if(m_decFactor == 8)
    {
        //////////////////////////////////////////////////
        b[0] = 0.060111378492136;
        b[1] = -0.257323420830598;
        b[2] = 0.420583503165928;
        b[3] = -0.222750785197418;
        b[4] = -0.222750785197418;
        b[5] = 0.420583503165928;
        b[6] = -0.257323420830598;
        b[7] = 0.060111378492136;

        a[0] = 1;
        a[1] = -5.667654878577432;
        a[2] = 14.062452278088417;
        a[3] = -19.737303840697738;
        a[4] = 16.889698874608641;
        a[5] = -8.796600612325928;
        a[6] = 2.577553446979888;
        a[7] = -0.326903916815751;
        //////////////////////////////////////////////////
    }
    else if( m_decFactor == 4 )
    {
	//////////////////////////////////////////////////
	b[ 0 ] = 0.10133306904918619;
	b[ 1 ] = -0.2447523353702363;
	b[ 2 ] = 0.33622528590120965;
	b[ 3 ] = -0.13936581560633518;
	b[ 4 ] = -0.13936581560633382;
	b[ 5 ] = 0.3362252859012087;
	b[ 6 ] = -0.2447523353702358;
	b[ 7 ] = 0.10133306904918594;

	a[ 0 ] = 1;
	a[ 1 ] = -3.9035590278139427;
	a[ 2 ] = 7.5299379980621133;
	a[ 3 ] = -8.6890803793177511;
	a[ 4 ] = 6.4578667096099176;
	a[ 5 ] = -3.0242979431223631;
	a[ 6 ] = 0.83043385136748382;
	a[ 7 ] = -0.094420800837809335;
	//////////////////////////////////////////////////
    }
    else if( m_decFactor == 2 )
    {
	//////////////////////////////////////////////////
	b[ 0 ] = 0.20898944260075727;
	b[ 1 ] = 0.40011234879814367;
	b[ 2 ] = 0.819741973072733;
	b[ 3 ] = 1.0087419911682323;
	b[ 4 ] = 1.0087419911682325;
	b[ 5 ] = 0.81974197307273156;
	b[ 6 ] = 0.40011234879814295;
	b[ 7 ] = 0.20898944260075661;

	a[ 0 ] = 1;
	a[ 1 ] = 0.0077331184208358217;
	a[ 2 ] = 1.9853971155964376;
	a[ 3 ] = 0.19296739275341004;
	a[ 4 ] = 1.2330748872852182;
	a[ 5 ] = 0.18705341389316466;
	a[ 6 ] = 0.23659265908013868;
	a[ 7 ] = 0.032352924250533946;
    }
    else
    {
        if ( m_decFactor != 1 ) {
            std::cerr << "WARNING: Decimator::initialise: unsupported decimation factor " << m_decFactor << ", no antialiasing filter will be used" << std::endl;
        }

	//////////////////////////////////////////////////
	b[ 0 ] = 1;
	b[ 1 ] = 0;
	b[ 2 ] = 0;
	b[ 3 ] = 0;
	b[ 4 ] = 0;
	b[ 5 ] = 0;
	b[ 6 ] = 0;
	b[ 7 ] = 0;

	a[ 0 ] = 1;
	a[ 1 ] = 0;
	a[ 2 ] = 0;
	a[ 3 ] = 0;
	a[ 4 ] = 0;
	a[ 5 ] = 0;
	a[ 6 ] = 0;
	a[ 7 ] = 0;
    }

    resetFilter();
}

void Decimator::deInitialise()
{
    delete [] decBuffer;
}

void Decimator::resetFilter()
{
    Input = Output = 0;

    o1=o2=o3=o4=o5=o6=o7=0;
}

void Decimator::doAntiAlias(const double *src, double *dst, unsigned int length)
{

    for( unsigned int i = 0; i < length; i++ )
    {
	Input = (double)src[ i ];

	Output = Input * b[ 0 ] + o1;

	o1 = Input * b[ 1 ] - Output * a[ 1 ] + o2;
	o2 = Input * b[ 2 ] - Output * a[ 2 ] + o3;
	o3 = Input * b[ 3 ] - Output * a[ 3 ] + o4;
	o4 = Input * b[ 4 ] - Output * a[ 4 ] + o5;
	o5 = Input * b[ 5 ] - Output * a[ 5 ] + o6;
	o6 = Input * b[ 6 ] - Output * a[ 6 ] + o7;
	o7 = Input * b[ 7 ] - Output * a[ 7 ] ;

	dst[ i ] = Output;
    }

}

void Decimator::doAntiAlias(const float *src, double *dst, unsigned int length)
{

    for( unsigned int i = 0; i < length; i++ )
    {
	Input = (double)src[ i ];

	Output = Input * b[ 0 ] + o1;

	o1 = Input * b[ 1 ] - Output * a[ 1 ] + o2;
	o2 = Input * b[ 2 ] - Output * a[ 2 ] + o3;
	o3 = Input * b[ 3 ] - Output * a[ 3 ] + o4;
	o4 = Input * b[ 4 ] - Output * a[ 4 ] + o5;
	o5 = Input * b[ 5 ] - Output * a[ 5 ] + o6;
	o6 = Input * b[ 6 ] - Output * a[ 6 ] + o7;
	o7 = Input * b[ 7 ] - Output * a[ 7 ] ;

	dst[ i ] = Output;
    }

}

void Decimator::process(const double *src, double *dst)
{
    if (m_decFactor == 1) {
        for( unsigned int i = 0; i < m_outputLength; i++ ) {
            dst[i] = src[i];
        }
        return;
    }
        
    doAntiAlias( src, decBuffer, m_inputLength );

    unsigned idx = 0;

    for( unsigned int i = 0; i < m_outputLength; i++ )
    {
	dst[ idx++ ] = decBuffer[ m_decFactor * i ];
    }
}

void Decimator::process(const float *src, float *dst)
{
    if (m_decFactor == 1) {
        for( unsigned int i = 0; i < m_outputLength; i++ ) {
            dst[i] = src[i];
        }
        return;
    }

    doAntiAlias( src, decBuffer, m_inputLength );

    unsigned idx = 0;

    for( unsigned int i = 0; i < m_outputLength; i++ )
    {
	dst[ idx++ ] = decBuffer[ m_decFactor * i ];
    }
}