I have had success using Mediatomb running on my Buffalo Linkstaion Live V2 NAS with my Samsung BD-C5500.
Mediatomb is a small media server that runs on Linux and Macs (I think).
I had to add a few lines to Mediatomb's config.xml file to get things to work. I can now play MKV, M4V, MPG and WAV files. No luck on AVI files.
I found the information over on CNET Forums and looking at Serviio's configuration files (as I recall). I posted my config.xml file at CNET as well.
The changes are highlighted below (I hope). There are path errors in my config.xml file as shown below and probably would not work as is. Forget the path errors and concentrate on the added lines that are highlighted with comments so you can see what is being changed and why. There are probably improvements that could be made.
Mediatomb's confix.xml file as modified to enable M4V, MKV, MPG and WAV file playback on Samsung BD-C5500. Also the STOP, PAUSE and PLAY buttons work (on remote) plus the <> buttons let you fast forward about 10 seconds at at time (pretty useless). On a side note, whoever posted the thing about using TOOLS (on remote) and then entering the time to jump forward or backward, Thank you. That solves a lot of problems for me.
<b><ui enabled="yes"><br />
<!-- Mediatomb UI asks for username and password --><br />
<accounts enabled="yes" session-timeout="15"><br />
<account user="yourusername" password="yourpassword"/><br />
<sqlite3 enabled="yes"><br />
<b><!-- Following line set to 'yes' hides PC Directory to Rendering Device --><br />
<pc-directory upnp-hide="no"/><br />
<!-- Following line set to 'yes' enables STOP,PAUSE,<> on Samsung --><br />
<protocolInfo extend="yes"/><br />
<!-- Samsung Custom Headers which make .m4v and .wmv file play --><br />
<add header="transferMode.dlna.org: Streaming"/><br />
<add header="contentFeatures.dlna.org: DLNA.ORG_OP=01;DLNA.ORG_CI=0;DLNA.ORG_FLAGS=0170000000000000 0000000000000000"/> <br />
<\/manufacturerURL --> <br />
<!-- modelName>BD-C5500/<modelName --><br />
<!-- Uncomment the line below if you have a Telegent TG100 --><br />