https://github.com/awawa-dev/HyperHDR/discussions/967
Probably not really useful with "normal" SDR sources, but might be useful for some weird loopback cases like outputting HDR via display port, capturing via capture card, connect it via usb 3.0 cable back to computer, get stream via v4l2 into application (I do not think cingg works with this specific format yet) .
Or replace DP video output with some game console...
Moar bits ! :)