I was using my HTPC with a wired connection and was able to watch IPTV from my ISP via igmpproxy. That works like a charm. Now i tried to get rid of that wire from my HTPC to the router (about 20m) and thought, i'll go with wifi. But i am somehow not able to get IPTV working now...
I have seen that i should use udpxy. But here Using udpxy to proxy multicast from LAN to WAN? it states that i should go with port bridging. Now i am absolutely lost - can someone tell me what the "correct" way is to get that working (without wire 
) and maybe with a bit of documentation - thanks!