[mythtv] Dynamic Ringbuffer and prebuffering pauses.

Stuart Auchterlonie stuarta at squashedfrog.net
Sat Dec 2 11:52:30 UTC 2006

On Sat, Dec 02, 2006 at 11:39:56AM +0000, Stuart Auchterlonie wrote:
> One thing I have noticed while testing is that if the video is 
> lagging behind then frames are dropped to make the video catch up.
> This is what I would expect to happen.
> The problem i've noticed is that there is a delay between
> the decision to drop frames and the frames being dropped.
> This leads to NVP overshooting the targeted sync, and then
> not having enough video frames to display, thus leading to
> a prebuffer pause.

I'll clarify what I mean by overshoot.

Initially NVP is in the state where it requires frames to be
dropped to correct the sync differences between audio and video.

It drops frames until it believes the sync has been corrected,
but shortly afterwards it hits the condition that the audio
is lagging to much and thus frames have to be doubled to slow
the video down to allow the audio to catch up.

Make sense?

Now the trick will be to stop it from dropping to many video
frames when it want to resync


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