Video player performance under different DE's

I’m on a quest to get the best performance on a RPI4 playing video from the mythfrontend player application that is the frontend to the MythTV DVR open source software.

I’ve recently found EOS ARM and I’ve been playing with MythTV on EOS for the last week or so. If I build the software from source it performs great on EOS-Plasma(X11, no compositor) and EOS LXDE but not as good on EOS XFCE. Since the mythfrontend is a QT app and it runs full screen I’m surprised at the difference in performance. Besides visually comparing I use the jitter in FPS. On Plasma I’m seeing less than 0.1 but as high as 0.7 on XFCE, which is noticeable.

What really has me puzzled is I originally was working this in Raspberry PI OS 64 bit where the graphic driver work really stared improving last year. However it was never good enough to run on top of the RPI DE which I think is LXDE based.

In RPI OS 64 bit we had to boot to the console and run mythfrontend using:
QT_QPA_PLATFORM=eglfs mythfrontend
However when I first tried to run this command on EOS ARM without a DE running, it started mythfrontend but I had no use of the keyboard to select options, so I couldn’t compare video player performance.

So as you can see I have a number of questions. I’m very glad that under EOS-KDE Plasma (X11,no compositor) it runs so well. Having to run from the console all the time limits the use of the RPI4 when not playing videos.


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I am not sure if I am following what all your questions actually are.

As for having to start it from the terminal, you can copy the .desktop file for mythfrontend to ~/.local/share/applications/. and then add QT_QPA_PLATFORM=eglfs to the EXEC line if that option helps you.

I actually only need to use QT_QPA_PLATFORM=eglfs mythfrontend if I
sudo systemctl disable --now sddm (or whatever WM is running)
and run from the console without any DE.

In lxterminal or konsole using a DE I just type mythfrontend

At this level of performance in EOS Plasma, I’d just keep running it that way or add mythfrontend as an application to the Multimedia group in the application menu.

The case for not using a DE is when you are making a MythTV appliance out of the RPI4 with a USB SATA SSD for a full OTA TV DVR. The RPI4 is very close to being the perfect device to do this at a cheap price. Using Network Tuners like the HDHomerun complete the package.

Maybe you could try to modify this to work with mythTV:

Disable the compositor.

Thanks, that did fix it for XFCE4.