Kivy VideoPlayer无法正常工作

Question

问题是Kivy VideoPlayer不想加载。当我只使用视频时，它会显示但没有声音，这不是我的目标。任何关于它为什么不能正常工作的建议。

Builder.load_string("""
<Calc>:
    BoxLayout:
        BoxLayout:
            orientation: 'vertical'
            Button:
                background_normal: '/Users/hm/Desktop/enter_button.gif'
                background_down: 'bitmap.jpeg'
            Button:
                background_normal: '/Users/hm/Desktop/enter_button.gif'
                background_down: 'bitmap.jpeg'

            Button:
                background_normal: '/Users/hm/Desktop/enter_button.gif'
                background_down: 'bitmap.jpeg'

        BoxLayout:

            VideoPlayer:
                source: '/Users/hm/Desktop/kivy/Lexus ISF.avi'
                    """)


class Calc(BoxLayout):
    # define the multiplication of a function
    def product(self, instance):
        # self.result, self.a and self.b where defined explicitely in the kv
        print("ss")

class TestApp(App):
    def build(self):
        return Calc()

if __name__ == '__main__':
    TestApp().run()

点击播放后，这是控制台的位：

[INFO              ] [GL          ] NPOT texture support is available
[DEBUG             ] [ImageImageIO] Load </Users/hm/Desktop/enter_button.gif>
[DEBUG             ] [ImageImageIO] Load </Applications/Kivy.app/Contents/Resources/kivy/kivy/data/../data/images/image-loading.gif>