That's one good boi!
But seriously, it's hard to tell if the dog was really meaning to attack the kid or just wanted to play. If the dog is aggressive, in most cases, it will almost always prioritize attacking another dog or animal before a person (granted not a dog it is cool with). If the dogs are indeed aggressive, you just don't keep animals like that around. No more excuses, they can get loose (like in the video) and hurt somebody or some other animal.
Either way, it's a scary sight, playing or not. Some dog owners think just because their mutt is jumping on a stranger wanting to play, it's okay. No, a stranger doesn't know that and shouldn't have to play "will he bite me or his he playing"?