[DVDnav-discuss] Invalid IFO for title XX (VTS_XX_0.IFO)

[John Stebbins]

dd exits when it encounters an error.  So you have an incomplete ISO.  You need to use something like ddrescue with such
discs.
You are probably encountering ARccOS protection.  If so, there will be a lot of bad sectors on the disc and it will take
a long time to copy it due to the many error retries that any copying program will encounter.

On 11/22/2010 07:06 AM, Loïc Minier wrote:
>         Hey
>
>  I'm creating ISOs of my DVDs, but I'm getting errors with some of them.
>  I suspect it's a copy protection scheme.
>
>  When playing the DVD directly, e.g. "vlc /dev/dvd", things "just work".
>  With some DVDs, "dd if=/dev/dvd of=foo.iso && vlc foo.iso" works
>  equally well (I need to run "vlc /dev/dvd" to CSS-unlock the data).
>
>  But with some DVDs which don't seem particularly scratched, I'll
>  receive exactly one read error during the dd (I'm passing
>  "conv=noerror" to dd to circumvent that); the resulting .iso file is
>  then unusable and shows various errors:
>  libdvdnav: Using dvdnav version 4.1.3
>  libdvdread: Using libdvdcss version 1.2.10 for DVD access
>  libdvdnav: DVD Title: TMS0EUW1
>  libdvdnav: DVD Serial Number: 3a8e11db
>  [...]
>  libdvdread: Get key for /VIDEO_TS/VTS_15_0.VOB at 0x002f01a5
>  libdvdread: Elapsed time 0
>  libdvdread: Get key for /VIDEO_TS/VTS_15_1.VOB at 0x002f0258
>  libdvdread: Elapsed time 0
>  libdvdread: Get key for /VIDEO_TS/VTS_16_0.VOB at 0x002f8be7
>  libdvdread: Elapsed time 0
>  libdvdread: Get key for /VIDEO_TS/VTS_16_1.VOB at 0x002f8c9a
>  libdvdread: Elapsed time 0
>  libdvdread: Get key for /VIDEO_TS/VTS_17_0.VOB at 0x00344d9e
>  libdvdread: Error cracking CSS key for /VIDEO_TS/VTS_17_0.VOB
>  (0x00344d9e)
>  libdvdread: Elapsed time 0
>  libdvdread: Get key for /VIDEO_TS/VTS_17_1.VOB at 0x00344dae
>  libdvdread: Error cracking CSS key for /VIDEO_TS/VTS_17_1.VOB
>  (0x00344dae)!!
>  libdvdread: Elapsed time 0
>  libdvdread: Found 17 VTS's
>  libdvdread: Elapsed time 0
>  Warning: call to srand(309709)
>  libdvdread: Invalid IFO for title 17 (VTS_17_0.IFO).
>  libdvdnav: ifoOpenVTSI failed
>  vlc: /build/buildd/libdvdnav-4.1.3/src/vm/vm.c:1485: process_command:
>  Assertion `0' failed.
>
>  I'm using Ubuntu 10.10's libdvdnav, libdvdread, and vlc with a
>  self-built libdvdcss.  I checked that Ubuntu's libdvdnav doesn't have
>  an embedded libdvdread, and neither does vlc.
>
>  I cherry-picked SVN r1215 from svn://svn.mplayerhq.hu/dvdnav/trunk into
>  libdvdread, but this didn't help.  I also took SVN r237 from
>  svn://svn.videolan.org/libdvdcss/trunk into libdvdcss just in case it
>  was the explanation for the CSS key issues.
>
>
>  There seem to be three issues at various levels:
>  - dd fails to read some bytes from /dev/dvd.  I'm thinking that this is
>    caused by the copy-protection scheme at the disc mastering level, and
>    that it's an intentional error; maybe this triggers some fallback
>    code pathes in commercial DVD playing software which are not
>    triggered when using a .iso file which has no error
>  - libdvdcss reports that the last title's key can't be cracked when
>    using the .iso file, but it works when using /dev/dvd (almost all the
>    time, albeit there was one case where it didn't work)
>  - libdvdread/libdvdnav are extremely unhappy with ifoOpenVTSI() failing
>
>
>  The error seemed similar to the one fixed by the addition of .BUP file
>  support, unfortunately this didn't help.
>
>
>  This happens on a range of Walt Disney DVDs
>
>
>  Is there some information I can provide on the failure to help track it
>  down?  I'm afraid I'm not familiar with the DVD specs.
>
>    Cheers,