Can I import movies recorded in AVCHD format using iMovie for Mac?
It is possible if you use iMovie '08/ Mac OS X v10.6.7 or later versions.
iMovie (v10 or later) and Mac OS X v10.9 are necessary to import AVCHD movies recorded in 50p/60p mode (PS mode).
Visit iMovie Supported Cameras for information about the compatibility of the camera and iMovie.
https://help.apple.com/imovie/10/cameras/en/index.html