如何使用gstreamer＆smpte将2个视频文件与gst-launch连接起来？

I have 2 video files (vid1.mov and vid2.mov), both have the same frame size and frame rate. I want to have 1 final video with shows vid1.mov and then vid2.mov, one after the other. I also want there to be a transition from one video to another (rather than an abrupt change of video), and have discovered the I have 2 video files (vid1.mov and vid2.mov), b