Playing vs. copying a DVD

[Pafnoutios]

Why do the DVD players (xine, ...) play copy-protected DVDs, but copyers (like k9copy) freeze on them?
Aren't they both using the same libraries? libdvdread? libdecss?

[dkeav]

some dvd's have a sudo encryption scheme called ARccOS, basically the place bad sectors on the disc that your player will choke on, if your dvdplayer supports dvdnav it follows the menus on the dvd which route around the bad sectors, unfortunatly not many of the programs that copy dvd's make use of dvdnav, because they really dont need to

ive run into this quite a lot, and some have been forced to use a couple windows applications that can handle arccos to dump out the file

ive got a svn copy of mplayer compiled with some experimental dvdnav patches and can dump the videos with mplayer's dumpstream feature and work with it from there

mplayer dvdnav://01 -dumpstream -dumpfile somefile.mpg

[Pafnoutios]

So if k9copy were patched (properly) to use libdvdnav, it would be able to copy those disks? Or would the patching have to be at one of it's dependencies?

DVDAuthor
libdvdread
growisofs
vamps

[dkeav]

im not familiar with this program, if it were to say use mplayer as its backend, then yes i suppose it would be possible

the patched svn copy of mplayer i have is not very stable though came from a gentoo overlay, it does work for dumping though, so i copied the binaries to a safe place and downgraded back to a stable version of mplayer with dvdnav support, btw libdvdnav will not work with mplayer, its a modified version of that code

what exactly is k9copy doing? going dvd to dvd? or dvd to say an avi file?

[Sepero]

dkeav's solution does not appear to be making a 'rip' so to speak. It appears to be decoding, then re-encoding the video to mpg. I imagine that this results in a loss of quality (however small).

[dkeav]

i havnt offered any solution yet, dvd's are mpeg2 data, that just dumped the raw mpeg data to your harddrive so that you can do whatever you want with it, all i did was bypass their encryption scheme, there is no compression involved in that step

http://en.wikipedia.org/wiki/Dvd#DVD-Video

[Sepero]

wtf? dkeav, you are now officially an avatar freak. You, je_fro, and JThundley should have you're own little sick club or something.

[dkeav]

heh was watching simspsons on random last night, just struck me funny :)