Challenges Streaming From Mac Pro 7,1 to YouTube

JasonVP

Member
Hey folks -

Log file attached.

I've recently started an experiment to see how well I can get an NDI source (my Windows box) to send its goods to my 2019 Mac Pro 7,1, which would then punt it to YouTube in all its 4K/60 glory. The NDI aspect works fine: I'm using their Screen Cap HX app which the OBS process on the Mac sees. I'm also sending audio over via my mixer through my Sound Blaster X7 (USB DAC/ADC) to the Mac as well. You'll note from the log files that the NDI audio is "lagged". I have it muted and am not using it at all.

The issue is that YouTube is barking warnings at me every so often. Almost seems like it's every 60 seconds, but I'm not positive. It will either tell me it's receiving NO DATA from me, or it'll warn me that the bitrate of stream it's receiving is too high (~93Mbit/sec). As you can see from the logs, I have it set to 50 Mbit/sec with a limit of 50 Mbit/sec. But I do see OBS telling me that it's sometimes sending more than 50. YouTube's 4K/60 limit is 51Mbit/sec, so that may be the cause of this.

The results for the viewers is a brief buffering every so often. Even though OBS itself is saying "Everything's cool here", YouTube is claiming otherwise. I'm certain it's not the actual network connection because I've a business class 1G symmetric fiber connection to the house.

Finally, and repeatedly, OBS seizes on me. It goes "Not Responding" with the beach ball of doom. I've read all the suggestions about deleting scenes, and did that. In fact, I even completely nuked EVERYTHING related to OBS: profiles, settings, directories, etc. Didn't matter. I still get the beach ball of doom repeatedly. I'm guessing that's 100% the cause of my buffering/losing data on YT.

For an encoder, I notice OBS on the Mac Pro has 2 "VT Hardware Encoder" selections. I'm not sure why or what the difference is between them. I'm using the second one.

Any suggestions or ideas? Or any other data I can provide? Lemme know. Thanks!
 

Attachments

  • obs-log.txt
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JasonVP

Member
For an encoder, I notice OBS on the Mac Pro has 2 "VT Hardware Encoder" selections. I'm not sure why or what the difference is between them. I'm using the second one.
Here's what I meant by that:

obs-vt.png
 

JasonVP

Member
Interesting: I downgraded OBS to 26.1.2 and noticed a couple of things:
  • There's only one VT H264 Hardware Encoder listed
  • OBS doesn't beach-ball of doom on me
I haven't tried streaming anything yet (still at work). But will do so later. Thus far, it appears to be positive.
 

JasonVP

Member
Latest:

I started another 4K/60 stream and YouTube did, at one point, complain I was sending > 90Mbit/sec even though I have both bitrate numbers set to 50000 Kbps. A while after that, I received another log message from YT saying "NO DATA" and then a moment later "STREAM HEALTHY".

It really seems like the "NO DATA" lines are lining up with OBS going into the beach ball of doom. The funny thing is the back-end streaming engine is still running. It's just the front end UI that's completely borked and unusable. Totally locked up. I have to use MacOS to kill the OBS process.

I was hoping verbose logging would help provide more interesting data, but: it just didn't. I started OBS from a bash prompt like:

./obs --verbose > ~/Desktop/obs-log3.txt 2>&1

The log file is attached. You'll see at the end it just... stops. That's when I killed OBS because its UI had locked up again.
 

Attachments

  • obs-log3.txt
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JasonVP

Member
Final follow-up: With help from the community on the OBS Discord, I learned of a work-around to this by hiding the Mixer/Volume control panel. Apparently the UI thread was working overtime trying to redraw that entire thing (~ 60 times/second) because of my 4K display and locking that thread up. It seems to be a bug/issue specific to Qt on Macs. Hiding the mixer panel drops the UI thread use/load right back to nearly nothing, thereby preventing OBS from locking up.
 
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