code: def OnAdjustVolume(self, event):
          
  
          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)
docs: Changes video volume