I'm a long time Linux user but new to Kdenlive in the last couple months.

I was using it on an old HP laptop I acquired from work (HP Elitebook 8460p; i5; 8 GB RAM; Intel graphics processor). I manage an IT department and have access to the equipment after it has been retired. The laptop worked surprisingly well but, we recently replaced some engineering class machines so I acquired one thinking it would be a good upgrade. It's an HP 8200 Elite orkstation class machine with an i7, 16GB RAM, and an NVidia Quadro FX 580. The laptop went to my son.

I thought it would help run Kdenlive more efficiently. That has not been the case.

My preview window flickers in and out. It's not a choppy sort of thing that proxy clips are designed to fix. I can hear the audio play smoothly but the video stays off and then flickers in and out periodically. Did I say the laptop went to my son? O well. What kind of geek would I be if I did not give my all to figuring this out?

Things I've tried after researching online for a couple of days ...
* Proxy Clips
* MLT environment changes in an attempt to use NVENC
* Latest NVidia drivers from NVidia repository
* Ubuntu studio additions (yes, grasping at straws)

I don't know where to go next.

I'm running Kubuntu 19.10 and the appimage of Kdenlive 19.12.3. I've also tried the nightly build of 20.07.70 with the same result as well as the 19.08 that is in the Snap package manager and the crusty, old version that installs alongside Ubuntu Studio.

Any help would be much appreciated.

Turn off NVidia proprietary drivers ... problem solved.