I’ve finally given up on my DVD drive. For a long time, VLC has been the only thing that would countenance even trying to play DVDs on it, and even that occasionally claimed that there was an audio CD in the drive until it was removed and put in again.
Now, after upgrading libdvdcss and unplugging a harddrive from the IDE channel my DVD drive is on, trying to play dvds gets me:
export DVDCSS_VERBOSE=2 && vlc /dev/dvd
libdvdnav: Using dvdnav version 0.1.10 from http://dvd.sf.net
libdvdread: Using libdvdcss version 1.2.9 for DVD access
libdvdcss debug: opening target `/dev/dvd'
libdvdcss debug: using libc for access
libdvdcss debug: disc is scrambled
libdvdcss debug: requesting AGID
libdvdcss error: drive would not authenticate
libdvdread: Could not open /dev/dvd with libdvdcss.
libdvdread: Can't open /dev/dvd for reading
libdvdnav: vm: faild to open/read the DVD
Epic fail. Other people have had this problem with AOpen drives, so I think it’s high time I got a new DVD rewriter. Preferably one that can write double-layer DVDs (which mine currently can’t).
The main reason I’m posting this is because, after I googled for problems with DVD playback, I discovered that almost no-one knows about the DVDCSS_VERBOSE environment variable. There’s a corresponding one (DVDREAD_VERBOSE) for libdvdread, although I couldn’t get that to do anything. I only found out about these debug variables by looking through the source code trying to debug the problem (after libdvdread claimed it couldn’t open /dev/dvd, but dd if=/dev/dvd of=/dev/null count=200 had no problems).
Oh, and strace is really cool. That was one of my debug steps, and one I’d never have thought of until I saw someone’s blog about it a few weeks ago.
Maybe I’ll finally be able to use Dragon player (which has a cool icon) when I get my new drive.
 At Spanner‘s suggestion, I fixed it by setting the region with regionset. Now Dragon Player works too! [/edit]