Okay...I believe he's only strumming the D, G, and B strings here.
The first chords is a G 9th (12th on the D, 12 on the G, 10th on the B).
The second chord sounds like D maj ( 12th on the D, 11th on the G, 10th on the B).
The third chord is an A maj (11th on the D, 9th on the G, 10th on the B).
The fourth is an F# minor (11th on the D, 11the on the G, 10th on the B).
I'm fairly certain that is what he's playing. He's got that Alex Lifeson (Rush) clean, jangly sound from the 80s that I really dig. Hope this helps out.