[MPlayer-users] read mounted dvds and expected behavior (minor question, not a problem)

[Adam Nielsen]

> When I insert an encrypted DVD and do:
> 1. mount /dvd
> 2. head /dvd/VIDEO_TS/VTS_01_1.VOB
> I get an i/o error and some i/o error in /var/log/kern.log

The reason why this happens is because when you insert a video DVD, the drive 
is "locked" so that you can't access the VOB data (to prevent piracy.)  When 
you play a DVD with any media player on any platform, a command is sent to 
the drive to "unlock" it and allow the player to read off the VOB data.

So when you try to read the data yourself, the drive is still locked which is 
why you get an error - but after you've run mplayer the drive has been 
unlocked and it proceeds without problems.

Cheers,
Adam.