What do you think the problem is?

To try and answer your question as I have been in aviation for over thirty years. The aircraft in questions looks to be an experimental and has a 2-cycle or rotary engine installed just from the sound of it.

Four cycle engines don't sound like that at all even running on one or two cylilnders.

They are only a couple of things that cause engine to miss fire and not run

1. Eletrical shorts to the plugs

2. Lack of fuel

3. Lack of air

If you have air, fuel and electircal the plugs will fire the and the engine will run.

I hear birds, a car going down the road, the camera operator talking. No idea what that thrumming sound is, could be the engine, maybe not. Don't know which way the wind is blowing either and in the past pan out shot, the airplane was quite aways away from his location.

No other ID info to know if there was an accident that way, sounds like he's just trying to find a reason to close the local airport.

It is not clear to me that anything is wrong. This could be a student practicing a forced landing. The audio quality is sufficiently poor that I cannot tell if the aircraft is making the noise or something else is, and it does not appear that the pilot is in any great distress. The fact that the voice-over is saying that the engine is making strange noises is not convincing.

Sounds like the canuter valve is opening too early, causing too much pressure in the muffler bearing assembly. If he's not careful, he'll lose all of his blinker fluid.

sounds like he's lost his fuel pressure or is out of fuel.

It's a stall.