[Pyqt] Videoplayer no funciona en windows 8

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'videoPlayer.ui'
#
# Created: Wed Mar 11 23:20:54 2015
#      by: PyQt4 UI code generator 4.11.3
#
# WARNING! All changes made in this file will be lost!

from PyQt4 import QtCore, QtGui

try:
    _fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
    def _fromUtf8(s):
        return s

try:
    _encoding = QtGui.QApplication.UnicodeUTF8
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig, _encoding)
except AttributeError:
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig)

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName(_fromUtf8("MainWindow"))
        MainWindow.resize(343, 336)
        self.centralwidget = QtGui.QWidget(MainWindow)
        self.centralwidget.setObjectName(_fromUtf8("centralwidget"))
        self.gridLayout = QtGui.QGridLayout(self.centralwidget)
        self.gridLayout.setObjectName(_fromUtf8("gridLayout"))
        self.videoPlayer = phonon.Phonon.VideoPlayer(phonon.Phonon.VideoCategory,self.centralwidget)
        self.videoPlayer.setObjectName(_fromUtf8("videoPlayer"))
        self.gridLayout.addWidget(self.videoPlayer, 0, 0, 1, 1)
        MainWindow.setCentralWidget(self.centralwidget)

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)
        self.new()

    def retranslateUi(self, MainWindow):
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow", None))

    def new(self):
        media_source = phonon.Phonon.MediaSource("video.mp4")
        self.videoPlayer.load(media_source)
        self.videoPlayer.play()
        print self.videoPlayer.isPlaying()

from PyQt4 import phonon
import sys

if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)
    widged = QtGui.QMainWindow()
    mainWindow = Ui_MainWindow()
    mainWindow.setupUi(widged)
    widged.show()
    sys.exit(app.exec_())