Do you think that rpi 4 would recognize hdmi to usb cable? It is compatible with Linux
maybe, i don't have PI4 so can't say. Most USB capturing devices are detected and recognized by Hyperion.NG
its HDMI to USB so chance is that it'll work.
when u have it, stick it in the PI and give a command in terminal,
if the device is in there you'll see it, probably will be recogized also then by Hyperion.NG