Upgrade to 30.1.2 Unable to stream QSV encoder error / rtmp-output failed to start

B

Bedford VA Church

New Member
New user here. Upgraded when received the notice of a new version on 4/4/24. It advised me to update the NDI plug-in, which I did. Today, the stream failed to start. I changed the encoding to software and was able to stream. But that created about a 1 second echo to the the audio, making the YoutTube Livestream unwatchable. https://www.youtube.com/live/vB_KtQsC5LA?si=Jmw7gAnjgUYDN-vc

I moved back to hardware encoding: Hardware(QSV.H.264), the only hardware option available to reverify the error and create the current log. Reviewing this error in the forum posts, I see that there are many possible causes. I installed the Intel Driver and Install Assistant and it said my drivers were up to date already. In reviewing my current log I see that there is a "

/sync point not found. (MFX_ERR_NOT_FOUND)" and later "Stream output type 'rtmp_output' failed to start!".

The current log file is here: https://obsproject.com/logs/8FUpLZhG67eaBRzv

The analysis of the file warns that the Intel GPU is not powerful enough to game and stream. The application here is a one camera (USB connected) operation which has worked fine in previous versions.

Thanks for any advice or counsel you all may have.
 
B

Bedford VA Church

New Member
Thanks for the quick reply. Will learn how to roll back, and put in a request for a new computer. Any advice on specs for this application?
 
L

Lawrence_SoCal

Active Member
That CPU is 11 generations old. And Windows 11 won't run on it, and Win10 will lose OS updates next year (ish).
So, make sure leadership knows to start planning for an updated computer (with NVENC capable [nVidia] GPU as mentioned. personally I'd go for GTX 1660 Super or newer for H.264 streaming. If future proofing, and want AV1, then you need a very recent GPU].
Our church tower PC is running on a i7-10700K, and the GTX 1660 Super (Streaming at 1080p30 7k bitrate, and with separate encoder settings, Recording at around 3X that bitrate) and that system has LOTS of headroom, with our specific setup (single camera 1080p60 NDI feed) . ymmv

As for observations [outside going back to v27.1.2 as alluded to above]:
- Why 60fps? As noted above, our camera is sending NDI feed to PC at 60fps, but OBS Studio is set for only 30fps, as we have no need/use for SloMo, and prefer bandwidth be used for better video quality than extra frames
- you have audio devices at 2 different sampling rates... never a good idea, and especially bad on under-powered hardware
- And 8GB RAM is on the low side, but whether impacting you are not I can't say with real-time hardware resource utilization monitoring data
- beware mixing NDI camera and USB webcam video feeds as they are likely to have a latency difference (made much worse by ancient for real-time video work CPU)

You are creating extra CPU, RAM, etc load by getting NDI feed for PowerPoint. I run our Service Bulletin in a Windowed PowerPoint Slide show on OBS PC. It does mean OBS Studio operator has to advance slides, but is a simple Windows Capture. If that is too much for you/your staff, you could consider something like a SteamDeck to give another person an input on OBS Studio PC without having to share keyboard. There are other approaches as well. In my case, I only have a portion of the PPTx Slide Show visible (largely covered by 'Digital Usher' browser monitor of livestream and comments)... I only need to mouse over a visible portion of slide show, and scroll mouse wheel.. no need to make Slide Show an active window, and I can advance slide easily... works fine for us

Presuming budget is tight, and no plans to support AV1 streaming in next 4-5 years, I'd be inclined to get a refurbished business class PC that is certified to run Windows 11 (as much as I'm avoiding Win11 for as long as I can .. ie, next year).. that should give the system a decent usable life. Avoid lower-end CPUs (ex i5/i3s), under 16GB RAM, etc.
 
Last edited:
B

Bedford VA Church

New Member
Tried installing just the obs-qsv11.dll from, first, 28.1.2, and then 27.2.4. Neither fixed the issue. Installing a full 27.2.4, which was our previous release before the upgrade, did solve the problem. I did not do an uninstall, I just installed over it, hoping to keep configurations. That worked for me. Back in business. Thanks for all the help. Now to move on getting funds to upgrade this dinosaur to something more recent.
 
You must log in or register to reply here.
Top