Importing iTunes Videos to Rekordbox Video

Hi, I'm finally working with rekordbox DJ and everything works fine. Now I would like to purchase the video package (which is quite expensive...) and therefore downloaded firstly the trial version. But here I can't import videos from iTunes which I purchased officially. Only ripped youtube-videos (which were imported to iTunes) can be transferred to rekordbox.

All videos are mpeg4-videos. Where is the trick?

Please help- thanks!