It's been 3 weeks since updating to Windows 11 and I have had no further problems. The stream has been perfect every week on our 4G connection. I understand what Christian is saying about the undesirability of using 4G but unfortunately we have no option and it seems to work OK for us in our particular location, except for this problem which I suspect is probably not linked to the 4G connection as we've run this setup for 2 years without previous issues.

So I can see 2 possibilities -
1-There was something in a Windows 10 update which caused issues with RTMP streaming to youtube. Windows 11 doesn't have the problem.
2-Youtube found and fixed a problem.

I would be very interested to hear from others who were having this, as to whether their problems continue or not.
@bulent-atlas
@STATORADIO
are you still having the problems?

I was still having the same problem yesterday. I have the same problem not only on 1 computer but also on 3 computers. Tomorrow I will install Windows 11 on a computer and try it. I completed 5 days of broadcasts without any problems with 13 mbit upload with web presenter. But I cannot stream via vmix.
https://www.youtube.com/...xaP0?si=JBuHrJHZFJIU1mzr

I am having the same issue. I have confirmed that it is VMix. I have OBS running and VMix. I can stream 4k at 30mbps on OBS everytime i try to stream but on vmix it will rarely work. If i restart the computer sometimes i will get the full 30mbps with Vmix. Im verifying it through task manager. 90% of the time though i get orange buttons and it crashes to 3mbps with VMix. I have 2 monitors....i can put OBS on 1 and Vmix on the other....start streaming on OBS to YouTube 30mbps...works flawlessly. Stop stream on OBS....start stream on Vmix...orange buttons....only sending 3mbps of the 30.

Video evidence that Vmix is the issue. Using Vmix Version 28.0.0.36 x64
youtube video

Whats crazy is that if i change a random setting like go from hvec to h264....it will work. But if i stop stream and restart it with what worked...it wont work again.

Windows 10?
I was having this problem every stream (I started the thread). Since updating to Windows 11 (no change in hardware or network connections) every stream is perfect. I can't explain why, but if you are on W10 and able to update to W11 it would be worth a try.
Of course there are many things could cause this problem so your issue may not be the same as mine.

The problem was solved for me without making any changes. I have been broadcasting at 7 Mbit speed with av1 codec for 3 days, no problems occurred.
https://www.youtube.com/...SAZY?si=hiKWhPcWkqgvi8vl

Hansi,

interesting information. From what I understand, the higher the compression profile, the higher the stream bandwitdh (see here for a good explanation).

What is your ping time to Youtube? Unfortunately I can only emphasize learnings from our tests:

If you get into higher bitrates with RTMP (around 8 Mbit/s) AND if you are leaving the continent/ping times are too high, than you are asking for trouble.
If you use mobile networks than you can have the same issues because of the ping times/latency there.

Did you stream vom South Africa? If yes, and this map of Google Datacenters is correct, than your stream was leaving the continent, was using RTMP and had a high bitrate. :-(

Reverting the H.264 setting to baseline might just brought you outside the critical range. A quick check with the Baseline/Main/High profile at a target rate of 8 Mbit/s showed slightly less bandwith with Baseline compared to Main and significant (around 1 Mbit/s) from Main to High. Test were not representative, just a first impression. Video material was the favourite "DJ in front of a seaside with lots of water, sky and drone shots". Lots of mishmash pictures for the compressor.

Did you do a cross test with OBS or Multistreamer? I would highly recommend this to find out if the problem is in the network or the application.

Thanks to all the people for doing the cross-tests with OBS. Both OBS and vMix AFAIK use FFMPEG or the GPUs encoder for H.264 encoding. After a bit of research in the "Advanced Setting" of OBS I get the impression, that OBS streaming uses Constant Bitrate (CBR) as default. vMix however seems to use variable bitrate as default. Depending on the network infrastructure you are on, not using CBR can create all sorts of problems when hitting the traffic shaping algorithms at the providers systems. This seems to be espacially true if you are connected to copper DSL, mobile networks or domestic fiber links. So, if OBS is fine and vMix is acting up, activate the CBR setting in the advanced H.264 dialog and give it a try.

In H.264 encoding the output bitrate is quite variable. So, if you are streaming the intro slide with no motion, you are at 500 kbit/s. If you cut to the crowd cheering at show start, you can peak at 10 Mbit/s. If the providers traffic shaper adjusted for (lets guess) 1,5 Mbit/s, it will take some time and frame drops to come up to speed again in the providers routers. If you are on RTMP, the TCP tries to catch up and will damage the transmission. Typically traffic shaping in networks means dropping packets. TCP tries to catch this up, but if there is not enough bandwith, it won't succeed and slow things down. Bad for video.. :-( If you are on SRT, this is UDP. Packets will be dropped, frames at the receiver will drop. However, the receiver will stay in sync. With RTMP, this will not work properly.

So for your next tests please check this:

• Ping time from your site to a.rtmp.youtube.com
  
• If you know the IP adress of a.rtmp.youtube.com, check its location with a GEO-IP service
  
• Do a cress-check with a speed-test server near the YouTube location, using LibreSpeed
  
• See how things work with CBR in vMix, in OBS and Multistreamer. Multistreamer gives you a lot of details, although it takes some training to read this correctly.
  

Please let us know about your findings. If the problems persist, we can do some more tests together.

Good luck,

Christian

I have been having these same issues for the last few months, but streaming to something other than Youtube, but same exact problem. Is the best approach to upgrade from Win10 to 11? I read the posts from others that this appears to have resolved the issues for them, getting off Win 10.

Has anyone from vMix support been able to validate this? Seems like too many people are having the same issues and there must be a clear fix that can be communicated to the community.