[MPlayer-dev-eng] Performance of libdvdread/libdvdcss

[Vicente Sendra]

> It still leads the two options open:
> 1) Something is different when using read vs. ReadFile
> 2) Authenticating the drive makes it go into "break MPlayer" mode
> 
> Does the same behaviour happen on other computers/with drives from other
> manufacturers, ...?
> 
> > If, as you say, both win32k and libc do the same thing, can libc read > > the disc the same way it does win32k? , i mean, authenticating the disc, > > getting the disc key and so on.

> If the issue is 2), then exactly that will make it go slow and break.

I don't know the inner workings of dvd authentication, but even in this case (authenticating gets into slow mode), it should be possible to:

authenticate.
get title keys.
unauthenticate ¿does this exist, is it just a close?

play the disc with libc using keys we've got.


It seems we only need title key to play titles:

###### win32k #######
libdvdcss debug: initial disc key 00:00:00:00:0b
libdvdcss debug: decrypted title key c0:00:00:00:0b
libdvdcss debug: title key is c0:00:00:00:0b

###### libc  #######
...
libdvdcss debug: at block 434176, still cracking...
libdvdcss debug: successful attempts 1/3, scrambled blocks 98178/438023
libdvdcss debug: vts key initialized
libdvdcss debug: title key is c0:00:00:00:0b

both result in the same title key, just win32k with disc authentication is faster doing it.