Strange DVD Drive Behavior
dfussell at byu.edu
Thu Apr 19 15:23:35 MDT 2012
I bought 2 surplus HP dc7700's with LG DVD burners that are acting kind
of funny. They will read CDs and data DVDs no problem, but not (most)
commercial DVD-Video discs. It complains that there is no media found
if I try to dd from it, vlc says (via the libdvdread/libdvdcss2
libraries) that it can't open the device. It does this in Windows XP as
far as I can tell, as well as each of the Debian squeeze/wheezy/sid
releases and every version of libdvdcss2 I tried from debian-multimedia,
and every debian kernel package since 2.6.32. So I don't think it's a
driver issue. There aren't any firmware updates for the drive that HP
has published, and LG has deferred any such update to the OEM.
Some internet forums suggest that the DVD laser is burned out, but that
doesn't explain why it has no problem with a data DVD (assuming it has 2
separate lasers), and I've even (while partly dissassembled) gotten it
to read a DVD-Video home movie I made with Cinelerra and DeVeDe (burned
from a different machine of course).
The really funny thing was, when I ejected that home movie, a warning
was displayed in Gnome3 to leave the disk in the drive while it finished
writing to the disk, though I had only been using it with VLC and Xine,
and I thought writing an ISO would finalize the disk. I'm a KDE user,
so I don't know if this is normal or not, nor what it might be writing
(access logs? MPAA spyware/trackers? "HP wuz here"?).
I thought it might be a DVD region code problem, but the correct code is
displayed in Windows. When I use regionset to see if resetting it will
resolve the issue, it says it can't open the device.
Yes, I'm a member of the cdrom group, but I have problems even when
trying things as root.
I'm starting to wonder if there is a DVD-Video enable DRM signal that
the bios or windows driver is supposed to send to keep all those open
source linux pirates from watching videos on purchased media, rather
than getting it from bit torrent like everyone else. Or if the this is
supposed to be an MPEG licensing scheme for enforcing periodic payments
for DVD codecs by disabling DVD-Video support at a predefined
obsolescence date, requiring a replacement purchase. I have a third
(much older) LG drive that as far as I can tell stopped working with
DVDs out of the blue one day as well (though I didn't have data DVDs to
test with at the time).
Or am I totally forgetting some obvious -enable-dvd-video kernel
parameter that I've long since forgotten about?
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