I have been asked to assist a friend who has a 2021 iMac without HDMI input to display an incoming video feed from a work laptop's HDMI output. I have a generic HDMI->USB adaptor that (on Windows & Linux) acts like a webcam and lets me see any incoming HDMI signal on the monitor. See below:
I've seen people on YouTube doing the same with Mac computers, but Ifound no explanation how this is actually done and what software is used.
Can any iMac owner point me to resources that help me do this on an Apple computer, and what software to use? In the YouTube videos they mentioned using QuickTime for it but I'm open to anything else that doesn't cost anything while we test is this is possible at all.
To clear up things: I am not looking to capture the image, just display the live image from the HDMI input with as little lag as possible.
Specific video capture cards like those from Elgado usually introduce a lag that's over a second which makes it unusualbe.