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

**

** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (qt-info@nokia.com)

**

** This file is part of the examples of the Qt Toolkit.

**

** $QT_BEGIN_LICENSE:BSD$

** You may use this file under the terms of the BSD license as follows:

**

**

** $QT_END_LICENSE$

**

#ifndef SPECTRUMANALYSER_H

#define SPECTRUMANALYSER_H

#include <QByteArray>

#include <QObject>

#include <QVector>

#ifdef DUMP_SPECTRUMANALYSER

#include <QDir>

#include <QFile>

#include <QTextStream>

#endif

#include "frequencyspectrum.h"

#include "spectrum.h"

#ifndef DISABLE_FFT

#include "FFTRealFixLenParam.h"

#endif

class FFTRealWrapper;

class SpectrumAnalyserThreadPrivate;

/**

 * Implementation of the spectrum analysis which can be run in a

 * separate thread.

 */

class SpectrumAnalyserThread : public QObject

{

    Q_OBJECT

public:

    SpectrumAnalyserThread(QObject *parent);

    ~SpectrumAnalyserThread();

public slots:

    void setWindowFunction(WindowFunction type);

    void calculateSpectrum(const QByteArray &buffer,

                           int inputFrequency,

                           int bytesPerSample);

signals:

    void calculationComplete(const FrequencySpectrum &spectrum);

private:

    void calculateWindow();

private:

#ifndef DISABLE_FFT

    FFTRealWrapper*                             m_fft;

#endif

    const int                                   m_numSamples;

    WindowFunction                              m_windowFunction;

#ifdef DISABLE_FFT

    typedef qreal                               DataType;

#else

    typedef FFTRealFixLenParam::DataType        DataType;

#endif

    QVector<DataType>                           m_window;

    QVector<DataType>                           m_input;

    QVector<DataType>                           m_output;

    FrequencySpectrum                           m_spectrum;

#ifdef SPECTRUM_ANALYSER_SEPARATE_THREAD

    QThread*                                    m_thread;

#endif

};

/**

 * Class which performs frequency spectrum analysis on a window of

 * audio samples, provided to it by the Engine.

 */

class SpectrumAnalyser : public QObject

{

    Q_OBJECT

public:

    SpectrumAnalyser(QObject *parent = 0);

    ~SpectrumAnalyser();

#ifdef DUMP_SPECTRUMANALYSER

    void setOutputPath(const QString &outputPath);

#endif

public:

    /*

     * Set the windowing function which is applied before calculating the FFT

     */

    void setWindowFunction(WindowFunction type);

    /*

     * Calculate a frequency spectrum

     *

     * \param buffer       Audio data

     * \param format       Format of audio data

     *

     * Frequency spectrum is calculated asynchronously.  The result is returned

     * via the spectrumChanged signal.

     *

     * An ongoing calculation can be cancelled by calling cancelCalculation().

     *

     */

    void calculate(const QByteArray &buffer, const QAudioFormat &format);

    /*

     * Check whether the object is ready to perform another calculation

     */

    bool isReady() const;

    /*

     * Cancel an ongoing calculation

     *

     * Note that cancelling is asynchronous.

     */

    void cancelCalculation();

signals:

    void spectrumChanged(const FrequencySpectrum &spectrum);

private slots:

    void calculationComplete(const FrequencySpectrum &spectrum);

private:

    void calculateWindow();

private:

    SpectrumAnalyserThread*    m_thread;

    enum State {

        Idle,

        Busy,

        Cancelled

    };

    State              m_state;

#ifdef DUMP_SPECTRUMANALYSER

    QDir                m_outputDir;

    int                 m_count;

    QFile               m_textFile;

    QTextStream         m_textStream;

#endif

};

#endif // SPECTRUMANALYSER_H