Multicast security cameras

I am attempting to setup a single site LAN to allow for multicast streams from IP security cameras.

I am using pim sparse dense mode and I have it enabled on the layer 3 VLAN for the security camera network. I have ip multicast-routing issued to globally enable multicast. I have also entered a class D multicast address on the cameras to send the stream. First question, and I think I know the answer, does each camera need to have a unique multicast address?

When I checked the ip igmp groups, there is a group that is random and not defined by any of the cameras. When I try to open the stream in VLC player, it errors out.

What am I missing?

Thanks