In version 4 it was no problem getting the metadata, and the meta event was listed among the events in the web guide. But now I'm having problems reading the metadata in the 5.1 version.
I have added a listener to this event: MediaEvent.JWPLAYER_MEDIA_META
It seem to work but I'm unable to get the variables. What is the new syntax here?
There is no "new syntax".
You are confusing the plugin API with the JavaScript API.
The JavaScript API documentation for the v4 & v5 players is here:
http://developer.longtailvideo.com/trac/wiki/Player4Api
and here:
http://developer.longtailvideo.com/trac/wiki/Player4Events