GSTFS is a filesystem for on-demand transcoding of music files
between different formats. It utilizes the gstreamer library for
conversion so any formats supported by gstreamer should also be
supported by gstfs. The filesystem's only requirement is that the
gstreamer pipeline begin with a filesrc with the name "_source"
and end with an fdsink with the name "_dest". The filesystem will
automatically substitute the filename and fd number in these
pipelines.

WWW:	http://bobcopeland.com/gstfs/