VRR Capture Issues with UGREEN 25173 and EZCOO EZ-SP12H21

[Exoruss]

Hello,

I'm using a UGREEN 25173 HDMI capture card with HyperHDR and an EZCOO EZ-SP12H21 HDMI 2.1 splitter.

My setup:

• Gaming PC with an NVIDIA RTX 4090.
• LG OLED55C1 (4K 120 Hz, VRR, HDR).
• EZCOO EZ-SP12H21 HDMI 2.1 splitter.
• UGREEN 25173 capture card connected to the splitter's second output.
• HyperHDR running on Proxmox (Debian 12 LXC) on a minipc

My main issue is that the UGREEN does not seem to handle VRR correctly.

When VRR is enabled:

• Capture works when my game set at 1080p120 (with slighty led flickering)
• Above 1080p120, the capture loses signal.
• 4K60 VRR or 4k120 VRR in game also results in no signal.
• The issue occurs in both HyperHDR and OBS Studio, so it does not seem to be HyperHDR-specific.

The EZCOO splitter itself works correctly with VRR when connected to another monitor.

I have also encountered intermittent USB errors in Linux:

uvcvideo: Non-zero status (-71) in video completion handler

I tested different USB cables, capture formats (NV12, MJPEG, P010) and resolutions and still no signal with vrr activated.

Is this a problem with my capture card?

Any help or suggestions would be greatly appreciated.

Thank you!

[awawa-dev]

Hi
It looks like you're expecting HDMI 2.1 capabilities from an HDMI 2.0 capture card (Ugreen).

[Exoruss]

I want to capture at 1080p60 or 120Hz using HyperHDR—not necessarily at 4K60Hz or 120Hz. I purchased the hardware recommended on the wiki. I’ve set the scaler on the Ezcoo device toward the Ugreen unit; however, toggling it on or off doesn’t seem to make much of a difference.

[awawa-dev]

VRR may introduces own limitation on both Ezcoo and Ugreen, not sure if the Ezcoo scaler works at all when VRR is active.

[Exoruss]

I tested without the ezcoo, just by connecting the ugreen to the PC and with obs. And as soon as I put some vrr, the capture card sends me no signal. Has anyone tested since these two combinations in game with the VRR?

[Exoruss]

ok, I tested the ugreen on its own without the ezcoo and the vrr works. The ezcoo on its own also works. It seems to be the combination of the two that is causing a problem. Can I replace the ezcoo with the ugreen for an elgato 4k x, to do directly 4k 120hz vrr hdr 10 bits and send this signal to hyperhdr via usb 3.0 5gb?