Phoebus image frame rate

[Jure Varlec via Tech-talk <tech-talk at aps.anl.gov>]

Dear all,

I have made a Phoebus display consisting of nothing but an image widget. All axes off, interpolation disabled. A color video streamed over PVA is unpleasant to look at, I'd say it has about 5 FPS, maybe. The IOC is on the same machine, so there's plenty of "network" bandwidth. I have tried pvmonitor and c2dataviewer, both had no issues streaming at 30 FPS. I've tried Phoebus 4.7.3 and 5.0.0.

I'm aware of Phoebus' delay settings, which have been set to:

org.csstudio.display.builder.representation/image_update_delay=10
org.csstudio.display.builder.representation/update_delay=10

No effect. Actually, there is an effect: if I set the image update delay to 1000 ms, I get 1 FPS as expected. But reducing it below ~200 ms doesn't increase it beyond ~5 FPS.

I consulted both artificial and natural intelligence and, after the AI had a look at verbose Phoebus logs and results of Java async-profiler, both agreed that the culprit is probably image decoding in Phoebus. I find that hard to believe. I reduced image resolution to 640x480 (the camera I use refused to go lower than that) and frame rate stayed at about 5 FPS. That makes no sense to me. I'd rather believe that there's some setting I don't know about.

Is there? Please?

Thanks,
Jure