Q1) I receive "Do you have libdvdread installed? I don't think so..." when I
    try to compile vobcopy.
A)  Did you install the -dev packages of libdvdread (and libdvdcss)? These
    include the header files needed for compilation.
    
Q2) When I call "vobcopy -i /dev/something" I receive strange errors.
A)  Um, you have to mount the dvd and give the mount-point to -i, so
    something like -i /cdrom, /dev files aren't allowed!
    
Q3) It takes me ages to rip something.
A)  Well, take a look into /var/log/messages. If you see something like this 
    Sep 29 04:02:03 some kernel: hdc: cdrom_decode_status: status=0x51 {
    DriveReady SeekComplete Error }
    Sep 29 04:02:03 some kernel: hdc: cdrom_decode_status: error=0x30
    Sep 29 04:02:04 some kernel: hdc: cdrom_decode_status: status=0x51 {
    DriveReady SeekComplete Error }
    Sep 29 04:02:04 some kernel: hdc: cdrom_decode_status: error=0x30
    Sep 29 04:02:04 some kernel: hdc: ATAPI reset complete
    
    you have found the reason. I cannot explain what this means, but I guess
    that the dvd is kinda broken. Explanation by someone from TAG
    (linuxgazette.com):
    HD access is assumed to be fast. So many kernel drivers lock interrupts
    for the moment of access. If the access suddenly takes seconds instead of 
    micro s the system gets temporarily hung. The access does take long because
    the drive will try several accesses, resetting head alignment, reaccessing,
    ..... then only reporting back with the error. This only allows the kernel
    to go on with normal proceedure.


Q4) Can I rip something that already sits on my harddisk, either as a iso file or
    as a directory?
    
A)  No, sorry. Libdvdread needs to figure out the title-keys. It might be able to
    also do this on stuff already on the harddisk, but I don't know how and hence
    vobcopy can't do it. If you know how, give me a hint!
    

Q5) Vobcopy stops copying in the middle. This is somewhat reproducibel.

A)  I've seen this too. It seems the movie studios implemented a new kind of copy
    protection system (mostly by going against the rules set forth in the "red book"
    standard). Vobcopy relies on libdvdread to read the dvd, and unfortunately develop-
    ment on libdvdread has mostly ceased. So, libdvdread and therefore vobcopy can't
    read it. Look into alternative-programs.txt to find a ripper that might do it.

Q5) Vobcopy spits out an error message:
"[Info] Writing files to this dir: /tmp/BASS_THE_MOVIE_SPECIAL_FEATURES/VIDEO_TS/
[Error] Hmm, weird, the dir video_ts|VIDEO_TS on the dvd couldn't be opened
[Error] The dir to be opened was: /media/BASS_THE_MOVIE_SPECIAL_FEATURE/VIDEO_TS"
Why is that?

A) User August figured out what might be the problem:

$ ls -ld /media/BASS_THE_MOVIE_SPECIAL_FEATURE^_/ | xxd
0000000: 6472 2d78 2d2d 2d2d 2d2d 2e20 3420 6175  dr-x------. 4 au
0000010: 6720 6175 6720 3133 3620 3230 3039 2d31  g aug 136 2009-1
0000020: 312d 3038 2032 303a 3338 202f 6d65 6469  1-08 20:38 /medi
0000030: 612f 4241 5353 5f54 4845 5f4d 4f56 4945  a/BASS_THE_MOVIE
0000040: 5f53 5045 4349 414c 5f46 4541 5455 5245  _SPECIAL_FEATURE
0000050: 1f2f 0a                                  ./.

See that last 0x1f char? Yep, some genius pressed this DVD with a trailing
US (unit separator) char in the name...

WORKAROUND:

Just mount the DVD somewhere else. Or move the mount:

sudo mount -M /media/BASS_THE_MOVIE_SPECIAL_FEATURE^_/ /tmp/blah
then straight "vobcopy -m" works.