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, -- Loïc Minier