I have two clips taken at the same time: one taken from a camera, one taken from an iPhone. I am going to switch between the clips to change angles, so I need to create a "New Multicam Clip". 

My problem is, that the clip from an iPhone for some reason is taken vertically, so I need to rotate it by 90 degrees. While it is easy to rotate a single clip back once it is on a storyline, there seems to be no option either to rotate the clip when it is in the library nor after it was combined into a multicam clip. What I get is a combination of a horizontal footage from a camera and a vertical footage from an iPhone.

How can I:
a) either rotate the clip when it is still located in the library, so it will be horizontal when multicam clip is being created?
b) or rotate by 90 degrees only one clip (angle) of a multicam clip?