[mythtv-users] Re:DVD playback

[Jim Paris]

> Have you set a region on this drive?  Most DVD drives (someone correct me 
> if I'm wrong) require you to set the region the first time you use it (and 
> many allow you to change the region 5 times or so before locking it for 
> good).  So if you don't have a region set and you're trying to view a 
> region-locked DVD disc, you'll get errors.

RPC2 drives only check the region during the title-key request, which
normally happens during the CSS authentication phase.  libdvdcss
has the magical feature of being able to crack title keys directly 
via a known-plaintext attack on the VOB, which means you never have to
request the title-key from the drive, and therefore you can bypass the
region encoding entirely.  It's all automatic; it'll be used if
necessary.

-jim