Ad hominem is the name of type of informal fallacy. I say that because the problem is that informal fallacies are more "rules of thumb" than hard fast strictly-defined philosophical terms. So often many different names will apply to the same fallacy or many different fallacies will occur in the same fallacious statement.
That said, this looks more to me like the genetic fallacy.
(1) I say P.
(2) You say, "you suck!"
(3) You say "I won't listen to you because no one from New Jersey is believable."
Then (2) is ad hominem
and (3) is genetic fallacy.
You might say (3) is a type of (2), but the basic rule is when a more specific fallacy is known, we use that name. The main difference is that genetic fallacy says I don't need to listen to you because you're a ... [white supremacist / homophobe / liberal / conservative / black man / non-native speaker of English] whereas ad hominem responds with the slur rather than claims it is a reason not to address the argument.
So in this case, the attack seems to be motivated in part by the use of youtube as a source. But then using the use of youtube as a source to impugn the claims made.