Most of the work happened in the libdatachannel! You can check out my PR here[0]
OBS already has everything around AV1, so I just needed to handle packetization :)
The `is_av1` is already going away. Bad code on my part <_< [1]
[0] https://github.com/paullouisageneau/libdatachannel/commit/a6...