OK It's probably a bit of confusion over how it was meant to work.hoglet wrote: ↑Mon Oct 15, 2018 10:24 pm
I'll need to refresh my memory of how this was meant to work. But I think the calibration is currently done just once, immediately after the Pi boots. So if you want to re-calibrate then you need to press the reset button. It does drift after a while.
The aim was not that this be perfect. Rather that when used with double/triple buffering the rate of buffer skipping would be once every few minutes or better.
In non-interlace, 623 was best and with interlace 624 was best with the bar moving very slowly.
I had assumed you were trying to keep a lock by effectively doing a software PLL continually varying the HDMI clock to keep the vsyncs aligned.
In theory that would stop tearing and might not require any buffering at all, eliminating the lag.