RPi4 and constant screen tearing (no VSync)

#1

Hi! Another day, another problem :slight_smile:
It seams like vertical synchronization is not working for me at all. My ofApp::setup() starts with:

  ofSetVerticalSync(true);
  ofSetFrameRate(60);

As a test I’m running a simple project that is drawing 4 bars moving from side to side. It keeps stable 60fps but tearing is visible at all times. Mostly by the screens edge, but can also jump to the middle.

IMG_2058
IMG_20581024×1365 189 KB

No temperature or voltage warnings. CPU at 20%.

Hardware: RPi4B+ 8GB RAM; 16GB microSD; FullHD 60Hz display.

Software: RaspberryOS Lite (Debian Buster), openFrameworks 0.11.0, GL fake KMS driver enabled, compositor disabled, forced turbo in config.txt.
Most of my setup described here: RPi4 + Buster Lite + oF 0.11.0

Mentioned it another thread (here: Arm video tearing), but no response and I’m still struggling finding solution.

#2

Hi

I dont have experience on last oF and rpi4 but i worked a lot on rpi3b+ and prev oF (dont remember if 10 or 9.8) and did not see that behaviour.

Seems like last oF use same window system as other platforms using the opengl raspberry driver…

Maybe you can try disabling opengl driver and use previous oF version that will use ofAppEGLWindow

#3

Hi,
thank for the tip. Tomorrow I’ll try to make my app run with Legacy graphic drivers. Maybe this will work.

I have some experience with oF10 on RPi3B+. I was really excited with RPi4, hoping to create something with oF that will use the extra computing power. But the VSync issue is making me nuts!

Anyway, today I’ve installed experimental kernel and VideoCore with rpi-update - still no luck.

#4

I think the point is also to use previous window system not a GLFW one, legacy mode and EGL window, i think im not confusing the names