It is possible to write a networking application which does not respect IANA's list of reserved port numbers.
For example a malware author might deliberately use such a port.
Many applications can be configured by the end user to use any desired port.
Just because someone registered a port with IANA for multicast video doesn't mean that all uses of that port on the Intertubes are genuinely using it for the registered purpose.
Maybe it's malware sending you credit-card numbers back to a zombie at 188.8.131.52. Maybe it is something entirely innocent. Maybe it is some peer-to-peer application (torrent) uploading or downloading some video or audio data?
$ dig -x 184.108.40.206
220.127.116.11.in-addr.arpa. 86400 IN PTR 81-64-155-202.rev.numericable.fr.
Looks like the destination is a PC belonging to a customer of a French ISP?