I'm trying to play a few of the rock riffs on this video but I can't seem to get them, the tuning i'm in is DADADD, cause that's what I thought it was, but something tells me its not.

What tuning is it and how is the riff played?
thanks in advance guys.

+78848739576647634 e-cookies to anyone who gets it right.
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Open G is what I'd guess... DGDGBD
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But the first 4 chords seem to be in DAD


But the couple of double stops/chords he strikes next I cant seem to get.
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