[mythtv] DVD playback issues, patch

[Mark Spieth]

> >It would also be worth trying to change the line to:
> >
> >avsync_avg = avsync_delay;
> >
> >... i.e get rid of the smoothing function altogether, seeing as that's
> >what might be causing the speed oscillation.

a big problem is that the initial value of avsync_avg is 0 which is not 
correct.
somehow it should be set to avsync_delay if it hasnt been set before.
with this it may be possible to increase the time constant as described 
earlier without impacting things.
also on dvd pts change, avsync_delay should be set to avsync_avg so that 
there is no discontinuity in avsync_avg
determination.

mark