I would use "Dimensions". That's the resolution of the video. For instance 1280 x 720, which would be HD, and 1920 x 1024 would be full HD. Dimensions could be added to the info panes, so you easily see what quality it's in. The resolution is also written in the tags "Width" and "Hights" tags. The Hight tag could be used to more quickly separate between 1024, 720 or below.
You can even add this to the caption in theater view, so you can see the resolution on all the movies with one glance. Or you can use an expression to fill out a tag that gives you tags like Full HD, 1024, 720, SD and so on, depending on the resolution.