Hi guys!!! So after like a year of trying to find a media server program that would play everything on the Panasonic, I finally got ahold of one of the serviio forum dudes, and we went over exactly what was needed for the 2012 GT50. I've tested, and it works very well. The issue was always that there wasn't a good profile for the Panasonic, because it doesn't support divx or xvid, and also, mkv files, when not transcoded, don't give the correct aspect ratio.
Anyways, I know most of you wouldn't mind being able to view all your stuff on your pc, so here's what I did. I got one of the Netgear WNCE2001 adapters, basically it's a standalone wifi adapter that you setup on a computer, then you just plug it into literally anything with an ethernet port, and it connects to whatever you told it to connect to. Great for this TV. And it's like $35. Anyways, you get that, then download serviio (it's free). Also go google the latest version of ffdshow. Install those 2, then you'll need to setup serviio. Basically you're just telling it to always give the best video quality, point it to wherever your media files are stored on your PC, and that's pretty much it. Oh, and also point it to a large space for transcoding. I think it deletes the transcoding files after it uses them, but still, you want to point it to a hard drive that will always have more than 10GB free, I'd say. More if you have super big video files.
Now is the only tricky part, but really it's not that tricky. You need to find your install of serviio (c drive, program files, serviio for me), then go to config folder, and right click/edit the profiles.xml file. At the very bottom, right before you see */Profiles* (*=< or > from now on, forum issues with those 2) you want to copy and paste the below. Afterwards, you just make sure that everything is in order. Each of these things that starts with *profile ID=whatever, and ends with */profile* is a separate profile, and you're just adding another one in. Make sure you're leaving everything alone in the rest of them. You're literally copy/pasting a profile right before the final line in the xml file. Now press save, but don't close the xml editor. Go to task manager, go to processes, end the process tree for serviio and the console (it will be 3 executables), then restart serviio, and watch for it in task manager. You'll see a CPU spike, then it will go back down to 0. If it ends itself in the first few seconds, you know something is wrong with what you copy/pasted, so try again, and follow directions better!
But really, that shouldn't be necessary.
After that, all you need to do is find your tv in serviio device list, and tell it to use this profile (panasonic viera (201x) by DenyAll. DenyAll is the awesome dude who created this by the way. He was extremely helpful.
Anyways, this should work with most Panasonic tvs, not just the 2012 GT50. It transcodes most things, though alot of other tvs don't actually need it. If your computer is slower, you might not be able to watch all your stuff stutter-free, but I've got a first generation i5 processor, and it runs it all pretty much fine.
Hope this helps. I read this thread a while back, and people were always having issues with tversity, serviio, even the stuff you pay for. This should fix all your problems, and it should take you about 10 minutes to setup.
edit: I'll recopy/paste the code later...... I seem to have messed something up. Give me a short while. Hm, maybe a little longer than a short while, but I'll figure it out, then update later. I'm very interested in finally getting this thing working.