At least the patents on DVDs are expiring if not already expired. The first DVD player was sold in 1996, and patents can be good for up to 20 years from the filing date, so it would seem that by late next year, all necessary patents should have expired.
This is HORRIBLE legal advice. Patent laws were different before 1996, that's why MP3 patents are still around (and will be until 2017) despite the fact that specifications were published back in 1991!
In the United States, "patents filed prior to 8 June 1995 expire 17 years after the publication date of the patent, but application extensions make it possible for a patent to issue" quite a few years after initial filing.
MP3 patents have mostly expired, though one US patent expires later this year.
I wish that was true, but it's certainly not: