Kwave::Filter Class Reference

#include <Filter.h>

Collaboration diagram for Kwave::Filter:

Public Member Functions
	Filter (int rate)
	Filter (const QString &command)
virtual	~Filter ()
QString	command ()
unsigned int	resize (unsigned int newnum)
bool	isFIR () const
int	rate () const
unsigned int	count ()
double	coeff (unsigned int index)
void	setCoeff (unsigned int index, double newval)
unsigned int	delay (unsigned int index)
void	setDelay (unsigned int index, unsigned int newval)
void	load (const QString &filename)
void	save (const QString &filename)

Private Attributes
bool	m_fir
unsigned int	m_rate
QVector< double >	m_coeff
QVector< int >	m_delay

Detailed Description

Holds a set of parameters for a digital IIR or FIR filter.

Todo:

use KIONetAccess in the load/save methods

more error checks in load/save (current code is too optimistic)

Definition at line 36 of file Filter.h.

Constructor & Destructor Documentation

Filter() [1/2]

Kwave::Filter::Filter ( int  rate )

explicit

Constructor, creates an empty filter with a given sample rate.

Parameters

rate	number of samples per second

Definition at line 47 of file Filter.cpp.

    :m_fir(true), m_rate(rate), m_coeff(), m_delay()
{
}

Filter() [2/2]

Kwave::Filter::Filter ( const QString &  command )

explicit

Constructor, creates a filter from a Kwave command string.

Parameters

command

part of the Kwave command with parameters

Definition at line 31 of file Filter.cpp.

References _, count(), m_coeff, m_delay, m_fir, m_rate, Kwave::Parser::nextParam(), resize(), Kwave::Parser::toDouble(), and Kwave::Parser::toInt().

    :m_fir(true), m_rate(0), m_coeff(), m_delay()
{
    Kwave::Parser parse(command);

    m_rate = parse.toInt();
    m_fir = (parse.nextParam().toLower() == _("fir"));
    resize(parse.toInt());

    for (unsigned int i = 0; i < count(); i++) {
        m_delay[i] = parse.toInt();
        m_coeff[i] = parse.toDouble();
    }
}

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~Filter()

Kwave::Filter::~Filter ( )

virtual

Destructor

Definition at line 53 of file Filter.cpp.

References resize().

{
    resize(0);
}

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Member Function Documentation

coeff()

double Kwave::Filter::coeff

(

unsigned int

index

)

Returns a filter coefficient.

Parameters

index

internal index [0...count-1]

Definition at line 109 of file Filter.cpp.

References m_coeff, and Kwave::toInt().

Referenced by rate().

{
    Q_ASSERT(Kwave::toInt(index) < m_coeff.count());
    return m_coeff[index];
}

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command()

QString Kwave::Filter::command

(

)

Returns the Kwave command string from the current parameters.

Definition at line 59 of file Filter.cpp.

References _, count(), m_coeff, m_delay, m_fir, and m_rate.

{
    QString s;

    s = _("filter (");
    s += QString::number(m_rate);
    s += QLatin1Char(',');
    s += _((m_fir) ? "fir" : "iir");
    s += QLatin1Char(',') + QString::number(count());

    for (unsigned int i = 0; i < count(); i++) {
        s += QLatin1Char(',');
        s += QString::number(m_delay[i]);
        s += QLatin1Char(',');
        s += QString::number(m_coeff[i]);
    }
    return s;
}

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count()

unsigned int Kwave::Filter::count

(

)

Returns the number of coefficients and delay times (order) of the filter.

Definition at line 102 of file Filter.cpp.

References m_coeff, and m_delay.

Referenced by command(), Filter(), rate(), resize(), and save().

{
    Q_ASSERT(m_coeff.count() == m_delay.count());
    return m_coeff.count();
}

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delay()

unsigned int Kwave::Filter::delay

(

unsigned int

index

)

Returns a delay time of the filter.

Parameters

index

internal index [0...count-1]

Definition at line 123 of file Filter.cpp.

References m_delay, and Kwave::toInt().

Referenced by rate().

{
    Q_ASSERT(Kwave::toInt(index) < m_delay.count());
    return m_delay[index];
}

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isFIR()

bool Kwave::Filter::isFIR ( ) const

inline

Returns true if the filter is a FIR one, or false else

Definition at line 68 of file Filter.h.

References m_fir.

{ return m_fir; }

load()

void Kwave::Filter::load

(

const QString &

filename

)

Loads the filter parameters from a URL

Definition at line 159 of file Filter.cpp.

References _, DBG, m_coeff, m_delay, m_fir, and resize().

Referenced by rate().

{
    unsigned int i;
    bool ok;
    QString line;
    unsigned int linenr = 0;

    QFile file(filename);
    file.open(QIODevice::ReadOnly);
    QTextStream in(&file);

    // type of the filter (FIR/IIR)
    while (!in.atEnd()) {
        line = in.readLine().simplified();
        linenr++;

        if (line.isEmpty() || line.isNull()) continue;
        if ((line[0] == QLatin1Char('#')) || (line[0] == QLatin1Char('/')))
            continue;
        break;
    }
    m_fir = line.startsWith(_("FIR "));
    qDebug("Filter::load(): fir = %d", m_fir);

    // order
    unsigned int order = line.remove(0,4).toUInt(&ok);
    resize(0);
    resize(order);
    qDebug("Filter::load(): order = %d", order);

    // read delays and coefficients
    i = 0;
    while (!in.atEnd()) {
        line = in.readLine().simplified();
        linenr++;

        if (line.isEmpty() || line.isNull()) continue;
        if ((line[0] == QLatin1Char('#')) || (line[0] == QLatin1Char('/')))
            continue;

        int spacepos = line.indexOf(QLatin1Char(' '));
        ok = true;
        if (ok) m_delay[i] = line.left(spacepos).toUInt(&ok);
        line.remove(0, spacepos);
        if (ok) m_coeff[i] = line.toDouble(&ok);

        if (ok) {
            i++;
        } else {
            qDebug("Filter::load(%s): syntax error in line %d",
                   DBG(filename), linenr);
        }
    }
}

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rate()

int Kwave::Filter::rate ( ) const

inline

Returns the sample rate in samples/second

Definition at line 71 of file Filter.h.

References coeff(), count(), delay(), load(), m_rate, save(), setCoeff(), and setDelay().

{ return m_rate; }

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resize()

unsigned int Kwave::Filter::resize

(

unsigned int

newnum

)

Resizes the filter to a new number of coefficients.

Parameters

newnum

new number of coefficients [1..]

Returns

new number of coefficients or zero if failed

Definition at line 79 of file Filter.cpp.

References count(), m_coeff, m_delay, and Kwave::toInt().

Referenced by Filter(), load(), and ~Filter().

{
    unsigned int oldnum = count();
    if (newnum == oldnum) return oldnum; // nothing to do

    // resize both arrays
    m_delay.resize(newnum);
    m_coeff.resize(newnum);
    Q_ASSERT(m_delay.size() >= Kwave::toInt(newnum));
    Q_ASSERT(m_coeff.size() >= Kwave::toInt(newnum));
    Q_ASSERT(m_delay.size() == m_coeff.size());

    // initialize the new entries
    while (oldnum < newnum) {
        m_delay[oldnum] = oldnum;
        m_coeff[oldnum] = 0.0;
        oldnum++;
    }

    return newnum;
}

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save()

void Kwave::Filter::save

(

const QString &

filename

)

Saves the filter parameters to a URL

Definition at line 137 of file Filter.cpp.

References _, count(), m_coeff, m_delay, m_fir, name, and Kwave::toInt().

Referenced by rate().

{
    QString name(filename);
    Q_ASSERT(name.length());
    if (!name.length()) return;

    if (name.lastIndexOf(_(".filter")) != Kwave::toInt(name.length() - 7))
        name.append(_(".filter"));

    QFile file(name);
    file.open(QIODevice::WriteOnly);
    QTextStream out(&file);

    out << ((m_fir) ? "FIR " : "IIR ") << count() << endl;
    for (unsigned int i = 0; i < count(); i++) {
        out << m_delay[i] << ' ' << m_coeff[i] << endl;
    }

    file.close();
}

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setCoeff()

void Kwave::Filter::setCoeff	(	unsigned int	index,
		double	newval
	)

Sets a filter coefficient to a new value.

Parameters

index	internal index [0...count-1]
newval	new coefficient

Definition at line 116 of file Filter.cpp.

References m_coeff, and Kwave::toInt().

Referenced by rate().

{
    Q_ASSERT(Kwave::toInt(index) < m_coeff.count());
    m_coeff[index] = newval;
}

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setDelay()

void Kwave::Filter::setDelay	(	unsigned int	index,
		unsigned int	newval
	)

Sets a delay value to a new value.

Parameters

index	internal index [0...count-1]
newval	new delay value

Definition at line 130 of file Filter.cpp.

References m_delay, and Kwave::toInt().

Referenced by rate().

{
    Q_ASSERT(Kwave::toInt(index) < m_delay.count());
    m_delay[index] = newval;
}

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Member Data Documentation

m_coeff

QVector<double> Kwave::Filter::m_coeff

private

array of coefficients

Definition at line 120 of file Filter.h.

Referenced by coeff(), command(), count(), Filter(), load(), resize(), save(), and setCoeff().

m_delay

QVector<int> Kwave::Filter::m_delay

private

array of delay times

Definition at line 123 of file Filter.h.

Referenced by command(), count(), delay(), Filter(), load(), resize(), save(), and setDelay().

m_fir

bool Kwave::Filter::m_fir

private

boolean if filter is FIR or IIR

Definition at line 114 of file Filter.h.

Referenced by command(), Filter(), isFIR(), load(), and save().

m_rate

unsigned int Kwave::Filter::m_rate

private

sample rate in samples/second

Definition at line 117 of file Filter.h.

Referenced by command(), Filter(), and rate().

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The documentation for this class was generated from the following files:

• libkwave/Filter.h
• libkwave/Filter.cpp