mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QTimer>
#include <QDebug>

#include <QAudioOutput>
#include <QByteArray>
#include <QIODevice>

class AudioManager : public QObject
{
    Q_OBJECT
    public:
        explicit AudioManager(QObject *parent = 0);

    public slots:
        /// plays data (as PCM)
        void playAudio(QByteArray data);

        void start();
        void stop();

    private:
        QIODevice* m_audioOutputDevice;

        // audio format, initialized with PCM values
        QAudioFormat m_pcmFormat;

        QAudioOutput* m_audioOutput;
};

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
        Q_OBJECT

    public:
        explicit MainWindow(QWidget *parent = 0);
        ~MainWindow();

    protected slots:
        void timer()
        {
            if (!m_playing)
            {
                m_audio.start();
                m_audio.playAudio(QByteArray(16*20, ' '));

                m_timer.start(22);
                m_playing = true;
            }
            else
            {
                m_audio.stop();
                 m_timer.start(200);
                //m_timer.start(10);
                m_playing = false;
            }
        }
    private:
        Ui::MainWindow *ui;
        AudioManager m_audio;
        QTimer m_timer;
        bool m_playing;
};

#endif // MAINWINDOW_H