I think I started a topic on this a good year or two ago but it was never a clear cut answer. I remember I got it working somehow (by installing DIVX and somehow a combination of Shark007 codecs). Now I cant for the life of me get it working, uninstalled everything, reinstalled just DIVX, still don't see them. Gave up on that then moved to Plex Media.
Now the problem is im not entirely happy with how it works. On some of my DLNA devices like my LG Plasma 60", Plex doesn't show thumbnails, sometimes it shows the wrong ones. Tried to talk those guys there and no real answer. Seems like there is no way for it to auto generate a thumbnail for ones that done have coverart embedded in the files (many of my MP4s have the coverart embedded).
At least the original built in Windows Media server would show thumbnails for MKVs and other files where I didn't have any embedded coverart images.
Id like to just go back to the Windows version but would like to know if someone has a clear cut way to know how to get MKVs and other types of files (like from my camcorder MT2S, MOV, etc) to show up.
Thanks
Dixit