rygel no plugin found

[Soho Soho123 <soho123 2012 gmail com>]

Dears,

I am new in Rygel.
I have problem about:
I have install
librygel-playbin.so
librygel-gst-launch.so to /etc/rygel-1.0/Rygel


But when I start rygel by "rygel" command in terminal
I got the message :
Rygel-WARNING **: No plugins found in 5 seconds; giving up..

Does anyone have idea about this message?
I see the short faq, that describes "shared-mime-info" should be
install well such that plugin detect will work fine.
But I donot know how to install "shared-mime-info",
My platform is an embedded platform for media render application.

Does anyone have idea about install shared-mime-info?

Thanks!