The following post formats got a specific type of content part that should get displayed:
A) What is the exact content (element) that is meant to get displayed for video & audio?
B) How would you get the relevant part of the post content that represents the post format?
C) What would you do with the rest of the content?
D) How would you know which format a audio/video player needs as there's nothin built in?
Note (ad C): How would a user know that she/he should only post eg. a "link" (post format) and not a link inside a text?
Note (ad D): As already asked by @bueltge there's no player.