If you use OBS to stream, and most of all if you're hooking up multiple PCs to broadcast, you may have noticed "severe stuttering, lag, and choppy audio/video". According to the latest Windows release known issues, you aren't the only one.
As pointed out in the latest Windows 11 Version 24H2 update post, OS build 26100.4946 (which launched on August 12) has broken NDI use for some streamers. Over in forums like the VideoEngineering Subreddit, users have been complaining about 'sudden lag and framedrops' in NDI streams for a while now.
Effectively, NDI is an interface that allows communication between many devices and achieves low-latency video and audio transferring. In streaming, this means you can hook up a camera, computer, and any other device into a single stream easily without injecting latency.
To give a bit more production value, you can use NDI on OBS (a streaming/recording software), where you can then swap between scenes. When you may want to swap scenes on the fly for a joke, or to ease transitioning from one game to another, making sure you can do it at the right time is important.
This is before mentioning that some streamers have dedicated rigs for streaming, so they can use all the resources in their main PC to run games or programs. Stutters not only worsen the quality of the stream (and could therefore lose viewers) but can also cause the stream to drop entirely.
Latest Windows update wreaking havoc on NDI feeds from r/VIDEOENGINEERING
OBS and NDI not working with the latest Windows update means that some streamers may have had to change their setup to accommodate the problem until it is fixed. Luckily, there is a temporary fix until Microsoft gets to the bottom of it.
"To work around the issue, NDI recommends manually changing the NDI Receive Mode to use TCP or UDP instead of RUDP." To do this, you can download and install the NDI Tools pack, then launch it. From here, go to the advanced tab and swap the receive mode to TCP or UDP. If you stream from one computer to the other, you will naturally have to do this fix on both.
RUDP, or Reliable User Datagram Protocol, is faster (and therefore provides less latency) than TCP (which is the highest quality), whilst being more consistent than UDP (User Datagram Protocol). Being the best of both worlds, it's the recommended and default choice for streaming. Even though this fix should suffice, streams will likely be a bit more stable when RUDP is back for users.
Microsoft is reportedly investigating the problem, and more information is expected to arrive soon.
