[mythtv] output mutex lock

[Brent Hills]

> 	The decoder:run() stuff holds the mutex while it's decoding, which it
> shouldn't really need to do (could just just hold when it's updating
> the ouput buffer).
>
> 	It could use a redesign, as it is actually inherited code from a
> completely different project. The problem is that it is a bit hairy to
> get into and redo, and it seems to work just about everywhere (with the
> apparent exception of some Redhat/Fedora distros).
>
> - thor

My development box is Fedora but I use a non-nptl distro for my production
myth system.  With prepackaged rpms though more people with Redhat/Fedora
are using Myth, it would be nice to resolve without the LD_ASSUME_KERNEL
work around.  NPTL is not going away for future Redhat based systems and
other areas in Myth (tv) seem fine...

I am currently cleaning up a patch to update metadata when files are
modified.  Once that is up (today or tomorrow) I will take a stab at the
mutex problem.  At least I have the OS to work with.

BTW I have yet to take a look at mfd.  Is it ultimately intended to
replace mythmusic at some point or work with it?  I have noticed the
steady stream of commits in the logs is it becoming stable/usable?

Brent.