[mythtv] Big audio update - suggestions and Core Audio patch

[David George]

Jeremiah Morris wrote:

> What I propose is to separate the ring buffer logic from the feeder 
> logic, and make the feeder thread an optional part of the base class.  
> I put together an implementation that adds the following:
>
> - The thread is started and stopped by virtual methods, so the thread 
> doesn't have to run in the 'pull' case.
>
> - A new method encapsulates the code to consume from the ring buffer 
> (most of the logic in the critical section of the feeder thread).
>
> - pauseaudio, audio_actually_paused, and killaudio are protected, so 
> subclasses can read these cases directly (and thus implement an 
> alternative to the first part of the feeder thread).

I finally got around to trying this patch out and I had to change the 
first arg of GetAudioData from void* to unsigned char* otherwise 
compiler complained (gcc 3.3.3).

Other than that looks and works good.

Thanks,
David