/***************************************************************************
     PitchShiftFilter.h  -  filter for modifying the "pitch_shift"
                             -------------------
    begin                : Wed Nov 28 2007
    copyright            : (C) 2007 by Thomas Eschenbacher
    email                : Thomas.Eschenbacher@gmx.de

    based on synth_pitch_shift_impl.cc from the aRts project

    copyright (C) 2000 Jeff Tranter <tranter@pobox.com>
              (C) 1999 Stefan Westerfeld <stefan@space.twc.de>
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/

#ifndef PITCH_SHIFT_FILTER_H
#define PITCH_SHIFT_FILTER_H

#include "config.h"

#include <QObject>
#include <QVariant>
#include <QVector>

#include "libkwave/SampleArray.h"
#include "libkwave/SampleSource.h"

namespace Kwave
{

    class PitchShiftFilter: public Kwave::SampleSource
    {
	Q_OBJECT
    public:

	/** Constructor */
	PitchShiftFilter();

	/** Destructor */
	virtual ~PitchShiftFilter();

	/** does the calculation */
	virtual void goOn();

    signals:

	/** emits a block with the filtered data */
	void output(Kwave::SampleArray data);

    public slots:

	/** receives input data */
	void input(Kwave::SampleArray data);

	/**
	 * Sets the speed factor
	 * @param speed factor as a double
	 */
	void setSpeed(const QVariant speed);

	/**
	 * Sets the frequency parameter
	 * @param freq the normed frequency
	 */
	void setFrequency(const QVariant freq);

    private:

	/** reset/initialize the filter and buffer */
	void initFilter();

    private:

	/** buffer for input */
	Kwave::SampleArray m_buffer;

	/** speed factor */
	float m_speed;

	/** base frequency */
	float m_frequency;

	enum { MAXDELAY = 1000000 };

	QVector<float> m_dbuffer;
	float m_lfopos;
	float m_b1pos;
	float m_b2pos;
	float m_b1inc;
	float m_b2inc;
	bool m_b1reset;
	bool m_b2reset;
	int m_dbpos;
    };
}

#endif /* PITCH_SHIFT_FILTER_H */

//***************************************************************************
//***************************************************************************
