[MPlayer-users] Re: how does mplayer circumvent region protected (RPC-2) DVD drives?

[Diego Biurrun]

Jonas Jermann writes:
 > I searched and found the place I got the idea from. It's 
 > www.videolan.org/libdvdcss/doc/
 >
 > I started to add a dvd authentication description to 
 > cd-dvd.html. Unfortunately I'm a bit confused now to put the 3 
 > description into one. Also I'm still unsure in which cases it 
 > will work and in which not (e.g. is it possible to watch dvds 
 > with a rpc2 drive that has changed the code 5 times?).
 > The page also speaks about raw devices could someone explain 
 > this to me in short (general and libdvdcss related)?

There was a thread about this on dev-eng a while back, it starts here:

http://www.mplayerhq.hu/pipermail/mplayer-dev-eng/2002-August/010065.html

Arpi explains quite a few details here:

http://www.mplayerhq.hu/pipermail/mplayer-dev-eng/2002-August/010069.html

This is more about mounting vs raw devices, but related and it should
also be documented at some point (It's on my evergrowing ToDo, but not
up front.), so while you're at it you might as well have a go at this
as well ;-)

 > A attached a patch but most probably it contains wrong 
 > information, so I'd be glad to get a bit help (if you want a 
 > proper documentation ;). Comments are welcome...

Looks nice.  Please make it more clear that dvdnav support is
currently abandoned.  I did not find any factual mistakes, but I'm not
familiar with the topic since I do not have a DVD drive..

While I'm at it I might as well add some spelling/wording
nitpicks (the rest of you can ignore the rest of this).

Diego


 > +  it was never finished properly and is therefor not recommended.</P>

s/therefor/therefore/

 > +<P>The authentication and decryption method of the new-style DVD support are done

is done

 > +  using a patched libdvdcss (libmpdvdkit2). The method can be specified over the

libdvdcss named libmpdvdkit2, specified by

 > +  <LI><B>cached key:</B> <B>MPlayer</B> looks for eventually already cracked

leave eventually out

 > +    keys to try and get the disc key, then it access and request the title key

accesses, requests

 > +    to read and decrypt and play the files. This is the most common method.

read, decrypt and play

 > +    data. This methode should always work (very slow).</LI>

method

 > +  <LI><B>title:</B> This method does not rely on a key exchange with the DVD
 > +    drive, but rather uses a crypto attack to guess the title key by knowing
 > +    the decrypted VOB content (vob has very strict file format, so it can be

VOB has a very
 > +    predicted well). On rare cases this may fail because there is not enough

I'd use either "in rare cases" or "on rare occasions".

 > +    encrypted data on the disc to perform a statistical attack, but in the
 > +    other hand it is the only way to decrypt a DVD stored on a hard disc,

on the other hand, disk