video flicker in OpenLP only

j_tizzle

I'm running openSUSE Tumbleweed with OpenLP 3.1. It's a dual-Xeon box with AMD Radeon RX 580 graphics.

All videos that are played from within OpenLP flicker terribly. The whole screen (the display screen) flashes white. This happens with any video. When playing the same videos from vlc directly (with the output fullscreen on the display monitor) there is no flashing. The problem seems to be in OpenLP. I've looked through all the settings and cannot find one that might help. What am I missing?

revncele

I see several threads that appear somewhat related for example:
https://discuss.openlp.org/d/6860-video-displays-bank-screen-while-playing-sound/9

There is something about starting the video on the AMD GPU.

j_tizzle

Oh, very interesting! Thank you. I'll try swapping with an NVIDIA card to see if the problem goes away.

It is strange, though, the problem only exists when calling vlc through OpenLP; running a video full screen through vlc directly does not exhibit this flashing. I'll try it with NVIDIA, though.

Thanks.

j_tizzle

Switching to an NVIDIA card did not help. I still get the flashing throughout the video. On a whim I turned off KDE's compositor and the flashing stopped, but I ended up with a black screen rather than video. I installed the LXQt desktop and was getting the same thing: a blank screen when video was playing. (Bear in mind the same videos play fullscreen when opened directly in VLC.) I enabled LXQt's compositor and videos now play—with a single white flash in the upper left corner of the screen when pressing play.

In my experience OpenLP is not usable in GNOME (my preferred environment) because GNOME devs won't allow disabling the overview on secondary monitors, which means any other activities that require opening apps, etc., interfere with the display of OpenLP. Now KDE seems to be unusable with OpenLP. Am I missing something? Surely others use KDE with this app. What am i missing?