Rectangular Video Boxes Instead of Squares

Is there any way to change the shape of the video box? I have a player who has bad internet and roll20 works best because he can not show whatever he needs to improve speed and stability. However, in OBS I can easily bring in each video frame, no problem, but they're still square.  We previously used disc where everything is rectangular.  So, instead of completely redoing my background layout, is there a way to make the video frame rectangular in proportion/shape?

Although you can't change the size in Roll20 (to my knowledge), you could crop them to rectangular in OBS. Just make sure your players don't sit too close to their cameras.