Letterbox 16:10 video *upscaling to 16:9* instead of stretching?

[Classy_Car]

Preamble / background

Hey everyone. I currently have a 1680x1050 monitor. The aspect ratio is 16:10. Currently if i try to record in my native resolution and then upload to youtube, the video downscales to 720p and looks terrible. To overcome this, I started recording at a base and output of 1080p. I stretched or letterboxed my video depending on the content. That resulted in decent looking footage and i have been using it up until now. However...

Main issue

I have realized that setting my base resolution to 1680x1050 (native res) and setting the output resolution to 1080p would result in much better quality. The only issue is that it stretches the output, resulting in a video that feels wrong.

Summary / What i really want to accomplish / TLDR

So basically, I'm wondering if there's a way that I can change the default behavior that is stretching the base 16:10 to the output 16:9 and instead letterbox it while keeping the upscaling

I want to have a 16:10 video letterboxed inside of a 16:9 video while still keeping the benefits of OBS's upscaling.

 

[phil1]

I think it might help to clarify better what it is you want. Are you trying to preserve the aspect ratio? Are you trying to avoid scaling? If you have a 16:10 source, then you will need to downscale and "pillarbox" it if you want to see all of it in a 16:9 video. Is this what you want?