Deezer bucket supplying Deezer Ids of :30s and regulars?

I am performing the following query:

http://developer.echonest.com/api/v4/song/search?api_key=&format=json&results=15&style=rock&bucket=id:deezer&bucket=tracks&limit=true&artist_min_familiarity=0.6&sort=tempo-desc&rank_type=familiarity

I get back Deezer tracks with foreign_ids that I parse down to the Deezer Ids. Some of them stream in the Deezer SDK - full songs... some are Ids for 30s previews. I am authenticated using the Deezer SDK as a premium user. Is there a way to find out which type the Id is before playing it? Is there something I need to do to tell EchoNest to ONLY give me Ids for full streaming tracks?