QMediaPlayer using problem

[iso0]

Hi, I use Xcode 4.6 on Mac OS X 10.8 and Qt 5.1. I want to use QMediaPlayer class in my application. Here is my code:
@
#include <QApplication>
#include <QMediaPlayer>

int main(int argc, char argv[])
{
QApplication a(argc, argv);
QMediaPlayer pl = new QMediaPlayer();
pl->setMedia(QUrl::fromLocalFile("Crashday.wav"));
pl->play();
a.exec();
}
@

But it doesn't work and in console I see:

objc[97058]: Class AVFCaptureFramesDelegate is implemented in both /Users/liri/Qt/5.1.1/clang_64/plugins/mediaservice/libqavfcamera.dylib and /Users/liri/Qt/5.1.1/clang_64/plugins/mediaservice/libqavfcamera_debug.dylib. One of the two will be used. Which one is undefined.
objc[97058]: Class AVFMediaRecorderDelegate is implemented in both /Users/liri/Qt/5.1.1/clang_64/plugins/mediaservice/libqavfcamera.dylib and /Users/liri/Qt/5.1.1/clang_64/plugins/mediaservice/libqavfcamera_debug.dylib. One of the two will be used. Which one is undefined.
objc[97058]: Class AVFCameraSessionObserver is implemented in both /Users/liri/Qt/5.1.1/clang_64/plugins/mediaservice/libqavfcamera.dylib and /Users/liri/Qt/5.1.1/clang_64/plugins/mediaservice/libqavfcamera_debug.dylib. One of the two will be used. Which one is undefined.
objc[97058]: Class AVFMediaPlayerSessionObserver is implemented in both /Users/liri/Qt/5.1.1/clang_64/plugins/mediaservice/libqavfmediaplayer.dylib and /Users/liri/Qt/5.1.1/clang_64/plugins/mediaservice/libqavfmediaplayer_debug.dylib. One of the two will be used. Which one is undefined.
objc[97058]: Class TransparentQTMovieView is implemented in both /Users/liri/Qt/5.1.1/clang_64/plugins/mediaservice/libqqt7engine.dylib and /Users/liri/Qt/5.1.1/clang_64/plugins/mediaservice/libqqt7engine_debug.dylib. One of the two will be used. Which one is undefined.
objc[97058]: Class HiddenQTMovieView is implemented in both /Users/liri/Qt/5.1.1/clang_64/plugins/mediaservice/libqqt7engine.dylib and /Users/liri/Qt/5.1.1/clang_64/plugins/mediaservice/libqqt7engine_debug.dylib. One of the two will be used. Which one is undefined.
objc[97058]: Class QTMovieObserver is implemented in both /Users/liri/Qt/5.1.1/clang_64/plugins/mediaservice/libqqt7engine.dylib and /Users/liri/Qt/5.1.1/clang_64/plugins/mediaservice/libqqt7engine_debug.dylib. One of the two will be used. Which one is undefined.

Please help me anybody