IMovie for OsX: vertical videos

Since iMovie for Mac at the time of writing alwayds creates landscape videos (1920x1080) regardless of the first video being portrait (540x1080), the only way to fix this was exporting at full resolution at the best quality, then run this command with ffmpeg

ffmpeg -i input_video_1920_1080.mp4 -filter_complex “[0:v]crop=540:1080:690:0” -c:a aac output_540x1080.mp4

That created a video of 540x1080 pixel in mp4 format.

Input

Output