An update on NDI: there was an open-source clean room implementation published 2 months ago and is still worked on.
NewTek or their lawyers have not contacted the author yet. He's bitterly disappointed, as half his reason for writing this was to piss them off. But he is the president of Videolan, and I guess that carries some weight.
A Mastodon instance for people interested in multimedia, codecs, assembly, SIMD, and the occasional weeb stuff.