Changes video volume

def OnAdjustVolume(self, event):
        """Changes video volume"""

        self.volume = self.player.audio_get_volume()

        if event.GetWheelRotation() < 0:
            self.volume = max(0, self.volume-10)
        elif event.GetWheelRotation() > 0:
            self.volume = min(200, self.volume+10)

        self.player.audio_set_volume(self.volume)