which made me wonder … if you use something like vlc, there is likely no way to play back regionally css encrypted DVDs since the vlc snap can not include this lib for legal reasons.
could the optical-drives interface perhaps allow access to an existing dvdcss setup on the host ? (paging @jdstrand)
My understanding of the decss scripts is they download and install things in /usr. /usr from the host is not available to strict mode snaps. Even if it were, I think the more snap-approved solution is for vlc to be a content provider for a read/write area, and then the user/another snap could drop files in the right location for vlc to pick up.