We are currently running Fedora Core 17 with gstreamer plugins: good, bad, ugly and the associated extras pages installed. We need a pipeline that will produce AUDIO & VIDEO output via Black Magic's Decklink SDI output using the decklinksink plugin. However, we have success outputting only video via decklinksink and we need audio too.
In the event that the existing decklinksink does not work, we would need a plugin for gstreamer that will. The sources for gstreamer and decklinksink are all available from http://gstreamer.freedesktop.org/src/