Different resolutions from inputs, when should i scale

[TGODneilan]

Alright so i play games in 1440p. but my cam is in 1080p, and my overlays/animations are 1080p. im streaming to a res lower than 1080p.

If i use 1440p, my cam and overlays would scale up to 1440p, then be scaled back down to stream res correct? Alternatively with a canvas of 1080p my gameplay would scale down once to 1080, then again to stream res. Which of these would be the better option?
Either way in theory that would mean that using a canvas that matches my output resolution would be less overall scaling, as all sources would only scale once to the canvas resolution. However, does the benefit of having all sources alias together post composite outweigh the benefit of only scaling each source once?

 

[TGODneilan]

If i use 1440p,

If i use a canvas of 1440p

 

[koala]

If you intend to increase your output resolution some time later, or if you just vary between different output resolutions, it is probably best to use the highest output resolution as canvas size, and if you want to stream at a lower resolution, you just switch the output resolution. This way your source layout can stay the same.

Some streamers created sophisticated overlays customized for one resolution - in this case, they use the overlay resolution as canvas and fit everything else. If you want text from your overlays as sharp as possible, you need to create your overlay for the output resolution and have canvas and output (and overlay) resolution the same, so the overlay isn't rescaled.

If some video-like source is dowscaled once or twice is probably not really visible. What you should really avoid, is upscaling.

More important is probably how big game UI an overlay text will appear on the stream after all downscaling. If you play in 1440p and stream with 720p, the size of your game UI will be rather small and probably not readable by your viewers. The same can be said of your overlay. If you want your viewers able to view some text of your game UI or of your overlay, verify your stream and keep in mind the majority of viewers have rather small monitors, not bigger than 1920x1080 (standard size: 24"), some only 1366x768 (Notebooks, standard size 15"), and not everyone will view your videos fullscreen.

What people use, see: https://store.steampowered.com/hwsurvey/Steam-Hardware-Software-Survey-Welcome-to-Steam