Webcam and Blackmagic Decklink out of Sync

[Kyula]

Hey guys

I got a Blackmagic Decklink Quad today (you can plug in 4 HDMI 4K inputs there).
It works like a charm.
Anyway I am doing a lot of streams where I am having multiple video source on the screen at the same time.
I use 3 camcorders and 2 Logitech Webcams
The big problem is, that they are totally out of sync.
The Logitech webcams have nearly no delay, while the Blackmagic inputs are having .5 - 1 second delay.
So even if I sync audio with one source, it will be out of sync with the other.
I couldn't find out, how to sync all video inputs in obs

Do you have any idea?

Thanks!

Benjamin

 

[TeakKey7]

Hey, that seems like a pretty annoying issue (I have the same issue but with audio), but luckily it should be a very easy fix. You'll probably need two people to sync it, but when someone claps, make sure the one with the least latency is in sync on your audio monitor before syncing the other cameras to that. To sync it, go under each camera source and in the right-click menu, go into the Effects tab, there you will see Render Delay, just type in 0-500ms, but if you're at something higher than 500ms, like ~700ms, just add another one at ~200ms for example.

I do have one question though, how did you get it working? My decklink is running at half (maybe even quarter) resolution. I'm not sure how it got messed up, I have a Duo 2 and maybe its an SDI thing, but im curious if you have that problem as well. I'll attach a picture of what i'm referring to. It's never worked properly and looks like 480p even though im using 1080i 50fps.




OBS on the left, ProPresenter on the right

 

[Kyula]

Hey,
thanks for your answers!
The Problem was that some sources were in 4k and some not.
If it put all sources to HD, everything worked fine.
As soon as one source is 4k, the audio gets out of sync.
Since I am streaming in HD only, that's no problem, I just need to think to switch to HD with all sources every time I stream, and switch back to 4k once I record