I'm pretty sure it is a re-broadcast by WOWOW.. since they often show concerts, plus notice that the date is not 12/31.
I would love to try to trade for one part of the concert.., but I don't know Japanese. I think I have enough files, but usually with rare files, you have to haggle out a deal.
It would be easier to get the concert from somebody else, efva has like everything!
Opennap is a network, you use Utatane to connect to it, there are tons of nice rare files there.
Btw, the full concert size is 16gb..