How to cut and shorten a movie automatically - perhaps in iMovie?

[panchen]

Hi there

I have a X minute long video, I would like to edit it, so out of (for simplicity) a 1 minute long video it shows 1 second of what is in the frame every 5th second.
Thus 1 video (1 min) shortens to --> 20 sec

And then I would like to add a 1 sec black screen between the 1-sec clips.
Thus the one minute video would last --> 40 sec

Also, I need to do this 4 times on the same video, with the 5-sec interval starting at different times. Is there a way to do this automatically? Or could I develop it?

I have no experience whatsoever in video-editing. Have only played with iMovies for a few minor projects.

Regards

[smrpix]

You want to do a basic speed up. iMovie says they can do that.

https://support.apple.com/kb/PH22933?locale=en_US&viewlocale=en_US

To start at different times, just drop the source clip on the timeline with a different in-point.