Actually this would mean to have a field like '(file) container' - which in case for DVD / (S-)VCD / videotapes either would be empty or just get copied from 'media' since it does not seem to be a useful information to know that VOB / DAT etc. are used here.
The Icon View in the grid could look like
Media Icon | Container Icon | Video Codec Icon
and in cases where no Container Icon shall get displayed and a question mark is not the wanted outcome an empty / transparent icon could get used.
Since I can imagine a lot of different usage scenarios this may need some discussion first. It's just that the current intepretation of what belongs into the 'media' field looks kinda messy to me.