Q1: Importing .m4v to Imovie
I have some old 8mm tapes I wanted to import. I have a DVD burner, so I burnt the tapes to DVD. Imovie wouldn't import that. So, I downloaded Handbrake and converted the DVDs to .m4v and .mkv. Imovie wouldn't import either of those either.
What formats does imovie import and are there any free converters to convert my unencrypted DVDs, .m4v files to it?

Q2: How to import a .m4v file (made in handbrake) into iMovie?
I was told that if I wanted to edit my DVD I had to convert it first with Handbrake, so I used Handbrake to convert my DVD and it became an .m4v file. But in Imovie I can't import that file, nor can I drag it from my deskboard into iMovie.
Any suggestion what to do?

Q3: Strange pillar box on left side only when importing .m4v to iMovie HD
I have some 853x480 widescreen .m4v video files I import into a widescreen (not high def) iMovie HD 6 project. For some reason, a black pillarbox is added to the left of each of these videos. The video is squished slightly horizontally to make room for this unwanted pillar, and no pillar is added to the right side.
Any ideas?

Recently, I found many questions about how to convert M4V to iMovie for importing and editing M4V with iMovie. Luckily, a friend of mine recommended me a M4V to iMovie Converter for Mac which he tried very great. I download the free trial and found it's very easy to use, and can convert M4V to iMovie formats MPEG-4, MOV, DV, HDV, etc for Mac OS. Then I bought it without any hesitating. If you have the same problem with me, maybe you can try it. Learn the details about how to convert M4V on iMovie! Hope to help you.