Package: dvdbackup Version: 0.4.2-4 Severity: normal
Hi. I made some tries with how to "best" archive some of may aging DVDs. First I found out that dd actually fails (with tons of block errors),... quite a surprise since I thought CSS was not acting on the block but rather on the file level. After some tries I've noticed, that when playing the dvd before with e.g. mplayer or something that uses libdvdcss/libdvdread dd/ddrescue etc. work just fine[0]. I also stumbled over dvdbackup, so I wanted to compare the results of dd with those of dvdbackup. The first thing I've noticed is: When I play to loopback device mounted dd image, it still does determine the CSS keys, so that image apparently still uses encryption (which makes me again not understand CSS) - any ideas? When I play the --mirror copy from dvdbackup it doesn't do deCSS again. Last but not least, the "bug" / improvement wishlisht: When I use e.g. lsdvd -x on the actual DVD drive, it gives me a: > Disc Title: LORD_OF_THE_RINGS The same on the dd created image files, but it's lost on the dvdbackup -M created files: > Disc Title: unknown I guess this is simply the from the UDF, so at least this and everything else which takes place at the UDF level is lost with how dvdbackup backups (also including file dates, owners, etc.) Another thing that's probably lost is some other title information: When you run dvdbackup -I on the actual disc it shows: > DVD-Video information of the DVD with title "Lord Of The Rings" The same when you run it on the dd created images, but this is gone when you run it on the dvdbackup -M created files: >DVD-Video information of the DVD with title "Lord Of The Rings" Not sure whether this "title" is also part of the UDF meta data,... in any case - it seems to be "lost". Another thing is, that dvdbackup "looses" any empty "AUDIO_TS" directory. All these losses may not look like a disaster (and probably they aren't ;-) ) but for those perfectionists which want to make perfect copies it's bad. My proposal would be, that one may perhaps add an --image mode, which creates and UDF image, but initialises CSS before (so that one doesn' get these block errors). Cheers, Chris. [0] When doing subsequent dumps of the disc with dd, there is still always one position with bit differences,... only a few bytes,... but I don't understand why - any idea? -- System Information: Debian Release: stretch/sid APT prefers unstable APT policy: (500, 'unstable') Architecture: amd64 (x86_64) Kernel: Linux 4.0.0-2-amd64 (SMP w/8 CPU cores) Locale: LANG=en_DE.UTF-8, LC_CTYPE=en_DE.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system) Versions of packages dvdbackup depends on: ii libc6 2.19-18 ii libdvdread4 5.0.0-1 dvdbackup recommends no packages. Versions of packages dvdbackup suggests: ii libdvdcss2 1.3.0-dmo1 -- no debconf information -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
