mono sound in imovie
I'm using a Mac mini, late 2014, OS X 10.11.6, El Capitan, and iMovie 10.1.4.
I'm having a problem with an MP4 file that has audio in the left channel only. I'm trying to find a way to make iMovie export the file in mono, so that the sound will be in both channels. I can't find a way to make that happen. Can anybody help me?