Background music

i am beginner for qt
i want to play background music in my app.i have used phonon api.when i tried to run no error and no music.
Mainwindow.cpp
Phonon::MediaObject *mediaObject=new Phonon::MediaObject(this);
Phonon::AudioOutput *audioOutput=new Phonon::AudioOutput(Phonon::MusicCategory,this);
Phonon::createPath(mediaObject,audioOutput);
QString fileName("Kalimba.mp3");
mediaObject->setCurrentSource(fileName);
mediaObject->play();
main.cpp
QApplication a(argc, argv);
Q_INIT_RESOURCE(BmiRc);
MainWindow w;
w.show();
return a.exec();
help me in correction of my app.

Please post the full files, using code tags.

mainwindow.cpp

Code:

---

#include "mainwindow.h"
#include <Phonon/MediaObject>
#include <Phonon/AudioOutput>
#include <Phonon/MediaSource>
#include <Phonon/BackendCapabilities>
 
MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
{
    qDebug()<<"sample program";
    qDebug() << Phonon::BackendCapabilities::availableAudioOutputDevices();
 
    Phonon::MediaObject *mediaObject=new Phonon::MediaObject(this);
    Phonon::AudioOutput *audioOutput=new Phonon::AudioOutput(Phonon::MusicCategory,this);
    Phonon::createPath(mediaObject,audioOutput);
    qDebug()<<"playing";
    QString fileName("/Kalimba.mp3");
    mediaObject->setCurrentSource(fileName);
 
    qDebug()<<"played";
    connect(mediaObject,SIGNAL(aboutToFinish()),SLOT(close()));
    mediaObject->play();
}
void close()
{
    qDebug()<<"closed";
}
 
MainWindow::~MainWindow()
{
 
}

---

main.cpp

Code:

---

#include <QtGui/QApplication>
#include "mainwindow.h"
 
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Q_INIT_RESOURCE(rsc3);
    a.setApplicationName("Sample Program");
    a.setQuitOnLastWindowClosed(true);
 
    MainWindow w;
    w.show();
 
    return a.exec();
}

---

output


sample program
("Default DirectSound Device", "DirectSound: Speakers / Headphones (IDT High Definition Audio CODEC)", "Speakers / Headphones (IDT High", "{4672319F-A9E7-4557-B6D3-D375388A529B}", "Default WaveOut Device")
playing
played