How to extract still frame as image file from a video on macOS?

- I want to capture some still frames from a video on macOS. - I can of course pause the video at desired frame and "grab screenshot to the selected part of screen" using ⌘ Command ⇧ Shift 4, but I'm looking for a more automated, accurate and easier way that doesn't require me to manually select the screen area of each frame. Is there a better way?