That just mean you don't have enough VRAM to process it
Usually only affected by resolution, and with the current version the only workaround would be to downscale it
I'm wondering if there should be an option to have any high-scale videos split into separate pieces so then after rendering a frame it stitches back together to compensate for lost VRAM?
I would guess it is totally possible. I will ask the developer about it
definitely, dainapp is developed by grisk too and i'm pretty certain it uses tiles for the "out of vram" option. cupscale and flowframes do too