[mythtv] multicast mpeg2 as an input (iptv discussion cont.)

[Michael J. Lynch]

Unit3 wrote:
> 
> I'm not entirely as up on multicast as I should be, but from what I
> understand, you get the kernel to join the multicast group, and then
> listen on the multicast address and IP you would normally connect to,
> and packets end up just coming your way.
> 

Multicast is indeed UDP.  There is a set of IP addresses designated
to be multicast IP addresses.  All you have to do is bind the socket
to the multicast IP address (group) and then join the multicast group
via a socket option (IP_ADD_MEMBERSHIP).  The trick to it is to get
the TTL value set such that if you multicast, the packets will make
it through routers along the way.  If your only receiving, you don't
have to worry about it.  The only thing you need to know is the
multicast group (IP address) and the port number being used.



-- 
Michael J. Lynch

What if the hokey pokey IS what it's all about -- author unknown