Screensaver takes too much time to fade-out...

[Marko Vojinovic]

On Thursday 15 December 2011 16:36:43 Patrick O'Callaghan wrote:
> On Thu, 2011-12-15 at 12:29 -0800, Joe Zeff wrote:
> > I was under the impression that codecs were executables and as such, OS
> > specific.  I presume that a Windows codec/trojan could run under wine if
> > you have it installed, but would it be able to do any damage?  Enquiring
> > minds want to *KNOW!*
> 
> They're usually libraries and may be cross-platform, e.g. the mplayer
> non-free codecs are designed for Windows but work in Linux as well.

That's not quite precisely true, those codecs do *not* work in Linux. Rather, 
the mplayer devs have reverse-engineered the various library calls in the 
codec DLL's, and are able to provide a simulated environment to make the 
number-crunching routines of various codecs work as in Windows (think virtual 
machine environment).

So the Windows codec DLL's used by mplayer are executed in a sandboxed 
environment and mplayer is just reading off the results of the calculations. 
There are no system calls available, no filesystem access, no network 
availability, no nothing. A real coding/decoding routine shouldn't need any of 
those, so mplayer doesn't even try to provide them. It's just using those 
"executables" as closed-source library routines, in contrast to the executable 
processes. Or put more simply --- there is a difference between an executable 
and an executable... ;-)

Those DLL's don't even work under Windows, without the support of an external 
parent process calling them, like mplayer. So those are perfectly safe, as 
long as the parent process is using them for the intended purpose only.

Now, using a Windows NIC driver under ndiswrapper (or something similar) is an 
entirely different ballgame... ;-)

HTH, :-)
Marko