Video Distortion and Color Bars in YouTube via OBS and Blackmagic

[rocworx]

I have run over 500 live streams using OBS in conjunction with YouTube. The last two days I have had an issue I have never seen before and I cannot figure out what is causing this issue. We are pushing a stream of PowerPoint slides and audio of a person talking. The audio is unaffected. The video glitches out with weird color bars. I can't find anyone else online having these issues. Does anyone have any ideas?

These pictures are what it looks like on YouTube. It shows on the YouTube recording if you go back in time. It seems to be inconsistent but happens throughout the day during our 6-hour stream.

Here is my complete setup:

Streaming computer:
MacBook Pro running Big Sur (11.2.3)
2.6 Ghz 6-Core Intel Core i7
16 GB 2400 MHz DDR4
Radeon Pro 560X 4GB

Blackmagic ATEM Mini connected with USBc to MacBook. Running projector out of HDMI Out on Blackmagic and a second MacBook running the powerpoint presentation through HDMI 1

Running Blackmagic video feed through OBS and then to YouTube. Blackmagic and OBS are both updated to the latest versions. I do not see the issues in the OBS preview, the video distortion only shows on the Youtube preview and on the actual YouTube stream.

I am running off a dedicated ethernet internet connection that has held steady at 20 mbps upload speed. I have had network issues before and this doesn't seem to be a network problem.

In OBS there are zero (0) dropped frames and the CPU hovers around 7%, 30 fps. The connection stays right around 2670 kb/s

Nothing has changed in my setup recently and we are running 3 other streams in different locations all with the same exact equipment/setup. The other 3 streams are not having any problem.

 

[ShadowBark]

That's interesting. We are using very similar setups for our streams. What I can say is that I doubt it's anything on the ATEM's side because it looks fine in the OBS preview window. Most likely it's something happening between OBS and YouTube. My best guesses on things to try would be (in no particular order):

A.) Try reconnecting your stream key.
B.) See if it's possibly a resolution error and try different resolutions.
C.) Try a trial stream (unlisted) without the ATEM (maybe just use a webcam and or the desktop display) and see if the problem still occurs.
D.) Try other programs for the slides such as Pro Presenter or Google Slides to see if it's just PowerPoint causing issues.

Not sure if any of these would help. This is a very strange problem indeed. If you have any other streaming software, maybe try using them to see if the problem still occurs. This will determine if it is an OBS problem or if it is a problem with the setup.

Good luck! Keep us updated. Maybe someone else knows a little more about this bug and how to fix it than I do.

 

[rocworx]

Thank you ShadowBark for your comments and I did try most of the things you suggested. I believe we have finally figured it out, although it does not make complete sense to me. Because of the distance for my cables, we had to run SDI conversion. We have run SDI quite a few times with no issues, but apparently, we had a bad cable or bad conversion box. When we swapped the SDI/boxes out it worked with no problems. This was very strange to me as no issues were showing in OBS.

Here is my theory:

It is my experience that Blackmagic is very good at adjusting on the fly to different resolutions and video signals coming into the box. I could have 4 different input types with all different resolutions and even unplug one and plug in a new one, but it is very seamless with transitions. What I think was happening in this certain situation is that the bad cable was causing some inconsistencies in the video feed, but Blackmagic was absorbing the video issues. The slight video changes passed through OBS undetected, but once it hit the actual live stream, YouTube was having trouble adjusting on the fly to the different signals being pushed through. I am by no means an expert and could be totally wrong, but all I can say is that we tried everything else to no avail. I never thought it could be a cable issue as we weren't seeing any problems in OBS, but the issue was there before we swapped out the cable, and immediately following the swap it worked fine. All troubleshooting was done in steps to make sure we could narrow down the problem. The cable swap was the only thing we changed for that instance.

 

[ShadowBark]

That's so interesting! Well, I'm glad you guys were able to figure it out. Thanks for the follow-up! Happy streaming :D