How to disable libdvdcss in smplayer?

gilpel at altern.org gilpel at altern.org
Fri Jul 31 03:02:50 UTC 2009


I believe I found what makes smplayer balk at mplayer's "-sb 25000"
option: it uses libdvdcss(1) and libdvdcss works on this section. So, I
believe -sb 25000 is just ignored. If libdvdcss doesn't work, that's it!

(1) libdvdread: Using libdvdcss version 1.2.10 for DVD access

I wouldn't mind losing a few seconds at the beginning of every movie --
even -sb 1750000 seems enough, but not 1500000 -- if this means getting
rid of css problems.

(Isn't weird that you can prevent scrambling problems just by ignoring
this section? What kind of prevention is that?)

Apparently, there is a --disable-libdvdcss-internal option but I haven't
found if that's what I need and where to use it... and I have a few things
to do before going to bed.

If you know how to prevent smplayer from using libdvdcss, it would be nice
to wake up tomorrow with a solved problem :)


Or maybe this could be an alternative method, not using the -sb option:

Setting environment variable...

DVDCSS_METHOD
              Sets the authentication and decryption method that libdvdcss
will use to read scrambled discs.  Can be one of title, key
or disc.

key
is the default method.  libdvdcss will use a set of calculated player keys
to try  and  get the disc key.  This can fail if the drive does not
recognize any of the player keys.

disc
is  a  fallback  method  when key has failed.  Instead of using player
keys, libdvdcss will crack the disc key using a brute force algorithm. 
This process is CPU  intensive  and  requires 64 MB of memory to store
temporary data.

title
is  the  fallback  when  all other methods have failed.  It does not rely
on a key exchange with the DVD drive, but rather uses a crypto attack to
guess the title key.  On rare  cases this may fail because there is not
enough 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, or a DVD with the wrong region on an RPC2 drive.

I must say the only result I got so far with this method is freezing the
system :(










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