Actually, more than this post, want to show that VLC has this setting Video->Crop-><options> e.g. 5:4, 4:3, etc. that can be used to display a region of video only
S. Janzen, W. Maass, und T. Kowatsch. Proceedings of 54th Annual Meeting of the Association for Computational Linguistics (ACL 2016), Seite 547--557. The Association for Computer Linguistics, (August 2016)