Discussion:
[libdvdcss-devel] Incompatible DVDs?
Whitney
2016-05-08 16:41:42 UTC
Permalink
Hi,

I recently started experiencing problems opening *some* DVDs. Take, for
instance, some of the recent DVDs that I have tried to open, such as Buffy,
Angel, and Boy Meets World season sets. These are all legit, region 1
releases and in flawless condition. Importantly, 90-95% of these discs
still do open and play just fine. Only some of them do not. For example,
all of Boy Meets World Season 1 opened, as did discs 1 and 2 of Season 2,
but Season 2 Disc 3 will not. I took it from one computer to another and
had the same problem there. The type of disc, region, and whether CSS is
present is static across both affected and un-affected discs. I can come up
with no explanation for why most discs are loading and a select few are not.

Some additional information to hopefully help narrow down the problem and
eliminate some likely causes:

- I am using Ubuntu 16.04 and, yes, I have installed the restricted formats
/ libdvdcss. About 90-95% of DVDs play with no trouble.
- I am using libdvdcss 1.4.0. I recently upgraded from Ubuntu 14.04 to
16.04 and my libdvdcss may have been upgraded with it, but I am certain
that I am currently using this version.
- I have purged and re-installed restricted formats / libdvdcss, but
continue getting the same problems for the affected discs.
- No, the DVDs are not physically unreadable or a different region; they
worked fine before the upgrade and still do on non-Linux devices that don't
rely on libdvdcss.
- This affects multiple computers (different makes and models) and DVD
drives (ditto), so it's not a hardware issue.
- I have tried deleting /.dvdcss folder and rebooting, but that solves
nothing (incidentally, the folder for the affected discs are empty, which
is what leads me to think that this is libdvdcss-related).
- The volume is loading as an unknown format according to Ubuntu's "Disks"
application, so it is recognizing that a disc is present (and it correctly
reads the size of the data on the disc).
- Wine-based programs also seem to be reading the disc label just fine, but
see no files present.
- Most damning of all that this is libdvdcss-related, the DVDs are
perfectly readable by MakeMKV, which I believe has its own decryption
codecs. Thus, software not contingent on libdvdcss can read the disc even
using the same hardware and OS.
- This only started happening after I upgraded to Ubuntu 16.04, but it's
possible that another software upgrade is the cause; I was only applying
minimal updates to the computer that I was mainly using for DVDs (it was on
14.04 before).
- The BMW discs in my example are not encrypted, but Bolt, for example, is
encrypted and reads just fine, so it is not an encryption problem.

I'm happy to provide additional information and run tests/commands as
needed.

Thanks,
Whitney
Jean-Baptiste Kempf
2016-05-19 20:39:11 UTC
Permalink
Post by Whitney
I'm happy to provide additional information and run tests/commands as
needed.
Can you share the failing logs?

With my kindest regards,
--
Jean-Baptiste Kempf
http://www.jbkempf.com/ - +33 672 704 734
Sent from my Electronic Device
Whitney
2016-05-19 22:52:38 UTC
Permalink
Hi Jean-Baptiste,

Thanks for your response. Do you mean the VLC log, or is there a higher
level log for libdvdcss?

As I tried to check the VLC log, I discovered that libdvdcss IS working for
these discs. I previously tried to get VLC to play the discs by trying to
select the disc (as opposed to the device), but because Ubuntu wasn't
recognizing the discs there was nothing to select. This time I was using a
different computer that only has one drive, so I didn't have to select a
disc and just pressed play without changing the disc device. Turns out VLC
can play the disc just fine once it's pointed to the correct device, even
though Ubuntu believes that the disc is unreadable. Because VLC is reading
the disc fine, there is no error message. After VLC opened the disc, the
css keys were dumped into the appropriate folder as normal.

Therefore, I believe that the problem is that Ubuntu 16.04 is not properly
using libdvdcss for certain discs. I still have no idea why most discs work
and select others don't, but it is consistent which ones do and don't work.
This is still an inconvenience as any program that relies of selecting a
disc or folder rather than a device will not be able to see the disc,
unfortunately.

Sorry for the confusion about the source of the problem!
Post by Jean-Baptiste Kempf
Post by Whitney
I'm happy to provide additional information and run tests/commands as
needed.
Can you share the failing logs?
With my kindest regards,
--
Jean-Baptiste Kempf
http://www.jbkempf.com/ - +33 672 704 734
Sent from my Electronic Device
_______________________________________________
libdvdcss-devel mailing list
https://mailman.videolan.org/listinfo/libdvdcss-devel
Loading...