Move Emfied on D6 to Media on D7 using migrate

I've been trying to understand this for a little while now, and would like some help. I have a D6 with a content type with an emfield that I use for video. I'm moving the site to D7 using the migrate module. I figured there would be some simple supported way to use migrate and migrate_d2d to move the content from the emfield to using the media module on the D7 site - but so far it looks like nobody has really written support for this. I would LOVE to be wrong about that, but the only migration path I can find for this involves using a traditional Drupal upgrade rather than using migrate.

Any suggestions would be really appreciated. I could well just be missing something obvious.