Yes. (Doing this really isn't necessary.)
Oh, you're asking how to do it?
It's a PNG stored in C:\Program Files (x86)\obs-studio\data\obs-plugins\win-dshow by default, placeholder.png.
I believe it has a resolution limit, a filesize limit and possibly some colorspace requirements, so make sure you just rename it to something else (rather than deleting or overwriting it) so you can refer back to the original in case your replacement image makes OBS crash.
Almost certain the built-in uses the same image in the same place, and the same type of 24-bit PNG.I dont mean the plugin
On which Path?Almost certain the built-in uses the same image in the same place, and the same type of 24-bit PNG.
and can I use gifs?On which Path?
Read up a bit in the thread. I listed the location before.On which Path?
No. 24-bit PNG, possibly with a resolution and filesize limit.and can I use gifs?