Question / Help OBS Load when Projecting a Different (but similar) Scene than Recording

[powdered_water]

Hey all,

Question:
So let's say I have Scene A and Scene B.
Scene A has a bunch of sources setup with a lot of filters.
Scene B is a duplicate, but has an added Text+ source (OBS Advanced Timer).

If I record Scene A and do a Full Screen Projector of Scene B to another monitor, is my computer having the process all of those sources and filters twice, or just the one time?

Scenario:
I am planning on setting up my studio so that I can have a confidence monitor that displays runtime. I'm using the OBS Advanced Timer to start a count-up after recording has started. I'm thinking about putting the Text source for that timer on a duplicate of the scene that I'm recording so I have a confidence monitor of what is being recorded.


tldr, if I full screen project source a scene with almost all the same sources at the scene that I'm actually recording, am I doubling the processing OBS has to do, or just adding in the processing for any additional sources in the scene?

 

[Narcogen]

If the sources are References, they should not double resource requirements. Having a duplicate scene with just text added is very usual.

 

[koala]

If you created Scene B with the "duplicate" function, every source in Scene B is created as reference. This way your computer still processes all corresponding sources only once. You can see this by changing some filter in one of these sources. You will observe that the change can be seen on the other source as well.

 

[powdered_water]

Fantastic! This is what I expected, but I just wanted to double check with the community before I started universally applying it to my client's recording sessions.

 

[koala]

By the way, duplicating scenes to have some kind of same overlay, branding or corporate identity in all scenes is not the best way to do. If you add or remove sources from the original scene, these changes do not carry over to duplicated scenes.

Instead of duplicating scenes, create a group that contains all sources you want to appear in multiple scenes. Call this group "branding" or something like this. Add it to every new scene you want your branding appear. If you change something within the group, add or remove sources, this will be carried over to every scene that contains that group.

Sources in a group are still all references, so the computer will process them only once (globally), not individually for every scene. So groups improve performance as well.

 

[Narcogen]

I think the point is to have certain items (lower third, other overlays) available as an option, and to be able to use a transition between them instead of just hiding a source.

I have a scene that includes all my usual content. (A)

Then I have a scene that contains all the overlays. (B)

And I have a third scene (C) that is a duplicate of (A) with (B) as a source on top.

Now I can cross-fade between (A) and (C) to turn the lower thirds on and off. For this I can use any transition I want, and I can use Transition Override Matrix to change the default transition used between different scenes if I choose.

Is there a way to achieve this with source groups instead of a scene? Without the "pop" of a quick cut that occurs when you enable a hidden source or group?

 

[koala]

As far as I see it, there exist no transitions for activating/deactivating a source or group. Transitions exist only for scenes. So what you do is the only way possible.
An optimization would be that you group all sources in scene A (into group A) and group all overlay sources in scene B (into group B). You create scene C empty instead of as a duplicate, and you add group A and group B. Now you switch between scene A and C for your stream. In this case, scene B has become obsolete and can be deleted, because group B still lives on in scene C, so in the end you only have scenes you will really use - which is one benefit of using groups.
If you need to redesign your overlays, you deactivate group A in scene C, so you only have the stuff visible that once was scene B, and change the sources in group B. Still no additional scene required you will never actually use for broadcast.

 

[Narcogen]

Thanks, I'll try that!