I bought a once bike that made a similar noise. I checked everything except the bottom bracket because I didn't have the right tool. When I finally took the bottom bracket apart, the bearings on one side were severely pitted. One bearing looked like a half-eaten apple. Luckily, there was no damage to the cups or spindle. The prior owner had stored the bike outside, leaning against a shed, so rain water had travelled down the seat tube and accumulated in the bottom bracket on one side. The stuck seat post should have been my first clue to check everything else a little closer.

Edit: I should have watched the video first before responding. That sounds like it is coming from the drivetrain and resonating through the frame. I would check the pedals, chainring bolts, and crank bolts. Does the noise occur on both chain rings, or only the large one?