Sorry if this is a bad place to ask, kind of out of ideas where else.
We're developing some VR hardware and using a monitor as the output display device during prototyping of our code. CRU has been a very valuable tool for this job by allowing to use non-standard refresh rates such as 90 (common in VR).
Occasionally I have a frame in a DisplayPort (DP) video stream being skipped at the monitor, and monitor displaying previous frame again. Tried with few monitors, the issue is present on 3, not present on 2 laptops with the builtin MIPI connected monitors but present on a 3rd one, and not present on a DisplayPort-connected consumer VR headset display but which has a closed-source PC runtime and PCB we can't analyze and learn from.
Happens at 60-240Hz.
Initially I thought something is wrong with out graphics code, but after trying many modes and settings in the code I'm starting to suspect the issue is the signal integrity at the cables or at the monitors causing a frame to sometimes be degraded enough to not be display-able. Once we present the frames to the graphics API, we can't ask the GPU to tell us what's going on with the frame and whether it reached the DP port successfully and on time or not. So I can't tell if it's the GPU skipping the current frame and sending the previous one for some reason, or if it's the Monitor displaying the previous frame from its own PCB framebuffer for some reason.
I could get some more monitors or better shielded DP cables or a DP booster device and run more tests, but I think a more valuable and reliable data right now would be one from a DP signal analyzer or tester either connected instead of the monitor, or sitting between the PC and the monitor, to be sure if the issue is caused by the PC motherboard or the cable used or not.
I don't need much functionality from the DP analyzer device other than detecing dropped/degraded frames and logging it to preferrably be accessible from the PC. Need it to handle up to 1080p at 240Hz, or at least 1080p at 180Hz.
Does anyone here have any experience with such devices? Which would you recommend for our specific requirement?
Finally, do you think a video created by a video capture card will be good enough for such tests? My fear is they may resample the frames so 1 frame IN does not always mean 1 frame OUT, even when input and output fps remains the same.
Thanks
We're developing some VR hardware and using a monitor as the output display device during prototyping of our code. CRU has been a very valuable tool for this job by allowing to use non-standard refresh rates such as 90 (common in VR).
Occasionally I have a frame in a DisplayPort (DP) video stream being skipped at the monitor, and monitor displaying previous frame again. Tried with few monitors, the issue is present on 3, not present on 2 laptops with the builtin MIPI connected monitors but present on a 3rd one, and not present on a DisplayPort-connected consumer VR headset display but which has a closed-source PC runtime and PCB we can't analyze and learn from.
Happens at 60-240Hz.
Initially I thought something is wrong with out graphics code, but after trying many modes and settings in the code I'm starting to suspect the issue is the signal integrity at the cables or at the monitors causing a frame to sometimes be degraded enough to not be display-able. Once we present the frames to the graphics API, we can't ask the GPU to tell us what's going on with the frame and whether it reached the DP port successfully and on time or not. So I can't tell if it's the GPU skipping the current frame and sending the previous one for some reason, or if it's the Monitor displaying the previous frame from its own PCB framebuffer for some reason.
I could get some more monitors or better shielded DP cables or a DP booster device and run more tests, but I think a more valuable and reliable data right now would be one from a DP signal analyzer or tester either connected instead of the monitor, or sitting between the PC and the monitor, to be sure if the issue is caused by the PC motherboard or the cable used or not.
I don't need much functionality from the DP analyzer device other than detecing dropped/degraded frames and logging it to preferrably be accessible from the PC. Need it to handle up to 1080p at 240Hz, or at least 1080p at 180Hz.
Does anyone here have any experience with such devices? Which would you recommend for our specific requirement?
Finally, do you think a video created by a video capture card will be good enough for such tests? My fear is they may resample the frames so 1 frame IN does not always mean 1 frame OUT, even when input and output fps remains the same.
Thanks
