better way to extract dvd audio with ffmpeg

[Linux for blind general discussion]

Have a look at vobcopy. The command

vobcopy -l

will get the title with the most chapters from your default dvd device 
and pipe it out to one large .vob file in your current working 
directory, giving it a filename that is the same as the title of the 
DVD. This looks like exactly what you're trying to do using the cat 
command you included, but without the repeated headers and bad data 
caused by the concatenation that makes ffmpeg complain. The man page 
lists a lot of other options that may also be useful, including 
mirroring the entire DVD and copying out one title from an already 
mirrored DVD or a specified mount point. You can also specify that 
multiple files be created with a given size limit, default is 2GB 
without the -l option. I did notice that my test copy made the filename 
the title of the DVD plus a 1 at the end, but I think that can be 
changed in options as well, especially if you want only one file.

~Kyle