Out of sync in OBS, but not for main stream

[oooshbro]

Hi all,

I have just switched over to OBS from Vmix due to using Mac's for work. So far everything is a lot easier having native software (we were using a virtual machine for vmix) but there is a non-constant delay between the audio and video in my program window in OBS. Non-constant meaning the delay changes throughout our streams.

The main stream which goes from OBS into Brightcove is fine, and totally in-sync, which is great, but it's still difficult to monitor/cut livestreams when the program window is out of sync.

More of an annoyance than anything, cause the main stream is fine.

Anyone experienced this and has a solution?

 

[AaronD]

You mean the audio Monitor specifically, is out of sync? Does it start good and get farther behind as the show goes on?

That's been a known issue for a long time. It's written not as a real-time low-latency thing, but as a network thing. If it hiccups, expand the buffer. Move on to the next part of the project.

If you send the Monitor to a sound card that uses a different clock than the rest of OBS does (some sound cards have their own dedicated, independent clock), then the same nominal setting will still be a slightly different speed. Maybe 47.9999kHz compared to 48.0001kHz, or something like that. That's a hiccup, and that'll expand the buffer...again...and again...until it's completely unusable but it's still dutifully expanding the buffer!

The stream and recording all use the same clock as the rest of OBS, so they don't have this problem.

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The solution is either to not use the Monitor, or to send it to something that uses the same clock, like a virtual device. Then you can send it from that virtual device to the real destination, and give something *else* a chance to get it right. Some sound cards also use the host's clock instead of their own, so they're okay too.

Or, you could disrupt the flow of audio to the Monitor, but that's a constant-maintenance thing. Change the Monitor device and change it back again, or change the routing settings, or blink the mute button, etc. All of that will reset the buffer, but it'll continue to grow and need resetting again.

 

[oooshbro]

Thanks for your detailed reply.

Yeah, just the audio monitor, and it isn't a constant delay, it changes throughout the stream.

I'll try some of your suggestions and see how I go.