Media player (or setting) to "fill in" letterboxing?

[Asterra]

Bog help me, I'm considering picking up an OLED display for regular (PC, media, gaming) use. I've researched this decision enough to recognize that the thing will burn in if I do anything less than treat it like royalty. Well, I watch a lot of 4:3 and 2.35:1 (etc.) content, and once again—contrary to anecdotes that stress otherwise—this is a legitimate risk for burn-in. Well, one workaround for the issue that I'm actually okay with, at least for 4:3 content, is that fakey "filled in" letterboxing you often see on e.g. Youtube videos of vertical smartphone footage. Instead of giant blank areas on the sides, it gets filled in with a zoomed-and-blurred copy of the actual video content. I imagine such a solution would at least drastically reduce the disparity in pixel usage on the display.

And since I'm almost certainly not the first person to decide they don't want to burn in their OLED display, I'm thinking there's either a media player that can already do this, or a filter or setting or something I can do with one of the popular players to get it done. So I'm hoping somebody will be willing to point me in the right direction.

[jagabo]

https://forum.videohelp.com/threads/399694-Filling-black-borders-in-Fullscreen-mode

[Asterra]

https://forum.videohelp.com/threads/399694-Filling-black-borders-in-Fullscreen-mode

So there isn't a way, outside of the obvious and equally inconvenient avisynth pre-arrangement? That's really kind of surprising, given how flexible some of the best media players are nowadays.

I wonder if the barrier to this advent is the fact that avisynth is "good enough" for the handful of people who actually understand the hazards of letterboxed content on an OLED display. And I'm also wondering whether any means might be devised to automatically generate an appropriate text file (right-click context menu) for any given video, so that at least the added encumbrance of the process can be limited to just a few more clicks.