To discover which plugin is used for specific file run command similar to this: gst-launch -v filesrc location=filename_here ! decodebin ! autoaudiosink
that should give you (among other things) output lines similar to these:
...
/GstPipeline:pipeline0/GstDecodeBin:decodebin0/GstTypeFindElement:typefind.GstPad:src: caps = application/x-id3
/GstPipeline:pipeline0/GstDecodeBin:decodebin0/GstID3Demux:id3demux0.GstPad:sink: caps = application/x-id3
Pipeline is PREROLLING ...
For setting up X server follow instructions here. (Long story short, use nvidia driver, add glx and extmod extensions to xorg.conf, and add argb-glx-visuals to monitor.)
If you created and compiled unit tests using MonoDevelop you need to copy several dlls to the same directory before you can use nunit-console with compiled dll. Those libraries can be found /usr/local/lib/monodevelop/AddIns/NUnit directory
I don't have any idea if mono-tools is still supported package, but its build is badly broken at least on FreeBSD. Anyway, the only tool I find really useful there is monodoc, which luckily can be installed manually like this: