[mythtv] Refresh rate during playback

[Kevin Kuphal]

Mark Spieth wrote:
> Run the same test with timestamp on as well as playback. generates lots of 
> log but will tell you what teh timestamps (a&v) are doing relative to each 
> other. perhaps also audio.
>
>   
I'll give that a shot.  What's really weird is that my backend RH9 
system that works also has messages about Video ahead of audio but then 
it prints the "I'm running at 30fps" message between them and it looks 
fine on the screen.

Kevin