[mythtv] Ticket #7964: Predictively skip frames to smooth out timestretch

[Mark Spieth]

> After a jump, how long it takes for the audio and video to get back in
> sync can vary a lot.  Sometimes it syncs back up almost instantly, but
> other times it can take over 5 seconds.  When it takes a while, it is
> very distracting -- especially if someone is talking and their lips
> have nothing to do with what they are saying ;-)
>
> Mark, I think this patch is the right direction, but I am hoping the
> A/V sync can be improved.
>    
can you get me a sample of the video that does it or a log with 
video,audio,timestamp and the events in question.
enable #if 0 in AVSync and also in vsync.cpp uncomment #define GLVSYNCDEBUG
unless you are using a different vsync to me.

note I also put in some stuff in avformatdecoder which should after a 
jump or start, only start accepting audio which has timestamps later 
than the video one. this could be the culprit for you. comment out block 
in this file about line 4043 which discards early audio packets and see 
if this helps. it may be that pts is the wrong one to use. dts might be 
better to use.

mark