This is the live stream...
Code:
rtmpdump -r "rtmp://194.219.221.195:80/vod/" -a "vod/" -f "WIN 19,0,0,226" -W "http://static.adman.gr/jwplayer.flash.swf" -p "http://www.alphatv.gr/webtv/live" -y "mp4:/2014-2015/preroll/MEGABLOCK.mp4" -o "2015-10-31_10-03-18_MEGABLOCK.flv"
The link you had posted does not play anything and I don't know Greek LOL