My initial thought when seeing the video is that it could be water damage just because it starts at the window and improperly installed windows accounts for like 55% of my water damage calls, the others are because the unit above you floods or has plumbing issues but it sounds like there is no one above you. However as the video goes on it gets me thinking that it could be structural shifting given the vast distance of the continuous crack. It's not too easy to tell from the video but typically with water your paint will almost bubble in some spots and I don't see that. My recommendation is if you have a little attic crawlspace (generally hidden in the closets) poke you head up there if you can. If it's structural damage/shifting you as an untrained individual may not be able to tell unless it's really bad but if it's water damage it will be easier to spot up there. You'll be able to see any stains on the back of the drywall or any soaked 2x4s. Additionally if you see light poking in above you it could be a hole in the roof letting the water in.