Ok, you were right guys! I installed MediaTomb per your recommendations, and
it works like a charm! Installation and configuration was easy as a pie
thanks to Gentoo's portage and MediaTomb's web UI. Moreover its DLNA is
compatible with my telly! Yay! :) Streaming of video, conversion of
unsupported formats and everything just works in five minutes of work! And
it is much better than Twonky Media Server which is the only officially
supported software by Panasonic.
Thanks for all your time guys!
Peter