Black flickering when displaying multiple 4K videos in qmlglsink
I'm using qmlglsink to display several 4K videos in an application (currently up to 4, in the future up to 8, when I'll have received some more hardware). The current hardware is the following:
- 2 4K cameras, let's call them A and B (there will be more in the future)
- 1 Blackmagic Smart VideoHub 12G
- 1 DeckLink 8K Pro (a second one will arrive in a few weeks)
- 1 Dell Precision with 2 Intel Xeon E5-2698 (40c/80t), 256GB of RAM and an Nvidia GeForce GTX 1080
When dispaying 3/4 videos, I often see a black flickering (there's a black frame and then the video is back). I reduced my code to the minimum and the problem is still there. When displaying 4 videos, the flickering is frequent enough to make the software unusable.
Say I'm displaying camera A twice and camera B twice. When a flickering occurs, it does for all the GstGLVideoItems showing that camera. So if A flickers, it will on the 2 GstGLVideoItems showing A, while B will not. An vice versa if B flickers.
If I start my app 4 times with one video in each instance, there's no problem (or maybe so rare that it's not a big deal).
I have a GStreamer development environment setup, and I can run some tests if needed.
It might be related to issue #396 , but there does not seem to be much activity there, and the op talked about artifacts, not black frames.
Thanks in advance for any help.