I did more digging and testing.
First off, I found out that VLC is now a UPNP player. VLC -> View-> Playlist, select UPNP and the sources show up. This is very helpful as it confirmed that gstreamer is actually streaming the files and they can be played by VLC. At least most of the embedded formats anyway. So the problem isn't gstreamer, per say. It works.
Second, I figured out that rygel is using gstreamer1. I figured this out by viewing the dependencies. rygel is dependent on gstremer1 and not on gstreamer.
I also found out I was missing a couple run time dependencies. Be sure to check the README in the source for the complete list. Here is what it currently is:
Requirements
============
* Build-time:
* Core:
* gupnp
* gupnp-av
* gstreamer
* gio (part of glib source package)
* libgee
* libsoup
* libmediaart
* vala (not if building from release tarballs)
* Preferences UI:
* gtk+
* MediaExport:
* sqlite3
* gupnp-dlna
* Run-time:
* Definitely needed:
* gst-plugins-base
* shared-mime-info
* Might be needed (depending on your usage and media collection):
* gst-plugins-good
* gst-libav
* gst-plugins-bad
* gst-plugins-ugly
I am pretty sure that my issue is related to the file mime type. It appears as though my Samsung TV (55JU7100) scans the files in the source directories and assigns a file extension to them.
When I am streaming test.mkv via the rygel media engine, it appears as test.mkv.mkv in the Samsung file directory. The first extension appears to be from rygel and the second extension appears to be added by the TV.
When I am streaming test.mkv via gstlaunch, the file appears as test.mkv in the Samsung file directory. If I change the gstlaunch mime type, the file extension changes. It doesn't appear that Samsung is adding the second file extension to the gstlaunch files.
So something about the way the file and its meta data is presented to the TV by gstlaunch causes the TV to interpret the file differently when it is sent via gstlaunch.
