how do I convert mp4 movies into photo app

Hi cfianpron,

It's unclear if your primary concern is adding videos to Photos or converting the file format. If you're wishing to add your videos to Photos check out Add photos and videos from the Photos app to your iMovie project.

For the conversion of file types, you may be able to use Export movies to other file formats and resolutions using QuickTime Player on Mac or a third-party application to accomplish this.

Regards.