How to prevent iMovie from changing aspect ratio on a video short in portrait mode?

Question

I shot a video in portrait mode on iphone, and its a mov file with a vertical aspect ratio (ie, when i open it in quicktime, it has no black areas on its sides).

I open that video in imovie version 10.3.5, and i cut some frames to shorten the video, i then export it as a mp4. Now when i open the mp4, quicktime has black areas on its side.

I read that i have to first preserve the original ratio by going to crop setting in imovie and select 'Fit', then edit, then export. I did that, and still it comers out with black areas on its side.

Same when I upload it to Google Video and play it, it plays in a very small window on my phone, whereas the orignal un-edited video plays on full screen veritically on my phone.

I've spent 8 hours on this and can't fix it.

How do I edit this video and still have it preserve original aspect ratio?

Answer 1

This is not a very elegant solution but it works.

Import your vertical video into iMovie.

When you have edited, rotate all the clips by 90 degrees

Export your video as a horizontal video eg "1080p" mode.

Open it in Quicktime Player

Rotate it back again:

Export it as 1080p.

The exported video will be rotated correctly: