[mythtv] still getting jitter/speed pulsing

[Isaac Richards]

On Friday 31 December 2004 05:52 pm, Mark Spieth wrote:
> Interesting observations. I have also been chasing this.
> I use busywait sync as none of the others work.
> what I have found is the call to show (XSync) is effectively a flush to X
> of the currently written page.
> I assume this is aligned with sync as it happens at that rate.
> my output display (monitor) is at 60Hz.
> my input frame rate is at 25Hz (pal)
> I have found that the minimum period between XSyncs is 33ms (2 output
> frames)
> and increases at multiples of the frame period (16.66ms)
> if the desired frame rate is close or > than the output framerate/2, then
> strange things start to happen.
> try using timestretch so that input rate > outputrate/2 and you see it
> clearly.
> for me this is > 1.2 as 25*1.25 > 60/2, 1.2 seems to work ok.
> frames must be deliberately skipped to compensate for this.
> I still dont have a good solution yet.
> havent updated to latest ffmpeg sync yet so still working off 24/12
> reverting libavcodec and libavformat back to 29/11 does nothing.
> still very confused as I dont fully understand the underlying xv behaviour.

Wouldn't you get better playback if you changed your refresh rate to 50hz to 
match your video?

Isaac