Information from website (http://live.gnome.org/Rygel):

Rygel is a collection of DLNA (UPnP AV) services (devices in UPnP
speak), implemented through a plug-in mechanism.

Important facts and features

* Specifically designed for GNOME (Mobile) and is therefore
  planned to be one of the key new features of Maemo platform in
  the Harmattan release.
* Based on GUPnP.
* written (mostly) in Vala language
* APIs to ease the implementation of AV devices (currently only
  MediaServer V2.0 specification)

* Export of on-disk media:
    o tracker plugin.
    o media-export plugin: Recursively exports folders and files specified in
      the user configuration.  This plugin supports all types of URIs that
      gio/gvfs and gstreamer can handle.
* Export of online media from 2nd German TV station.
* Export of media hierarchies provided by external applications through implementation
  of D-Bus MediaServer spec.  Applications that utilize this feature are:
    o PulseAudio: Provides streams for input/output devices on the system.
    o DVB Daemon: Provides live TV (DVB) channel streams.
    o Export of GStreamer pipelines as media items on the network, specified
      through gst-launch syntax in the user configuration.

* Audio and Video Transcoding: source format could be anything GStreamer's
  decodebin2 can handle but output formats are currently limited to: mp3, PCM
  and MPEG TS.  Fortunately the transcoding framework is flexible enough to
  easily add more transcoding targets.