%vlc -vvv --ipv6 udp:@[ff08::1]
Under Unix/Linux, you may have to protect the square brackets around the IPv6 address :
%vlc -vvv --ipv6 udp:@\[ff08::1\]
You may have to specify the output network interface :
%vlc -vvv video1.xyz --ipv6 --sout udp:[ff08::1%eth0] --ttl 12
where eth0 is the name of the network interface (under Linux the network interfaces are named ethX, under Mac OS X it's enX and under Windows it's X, where X is the appropriate number) .