I want to record on OBS a short section of a course lecture in mp4 that plays nicely full screen in Windows Movies & TV app. I can't figure out how to configure or what capture device to use to be able to do that. My default playback app for mp4s is VLC. It plays movies fine in full screen, but when I try to play the course lecture, VLC plays it in a small screen that crops out much of the view. I haven't been able to find how to set that not to happen in VLC. Since Movies & TV is not my default app, I have to select the file and then Open with, and select the app. It plays full screen without any cropping, but now I can't get OBS to show it as a video source. I see a VLC source and I tried that. Adding the file it opens full screen nicely without the cropping, but I get no sound at all and can't figure out how to configure that so it will work. Can someone help me with this please?