taking still frames out of video via terminal

[dramadeur]

/Applications/VLC.app/Contents/MacOS/VLC /Users/User/Desktop/test.mp4 --video-filter=scene --scene-prefix=movie --scene-ratio=1 --scene-path=/Users/Admin/Desktop/VLC --start-time=10 --stop-time=20 --no-skip-frames vlc://quit


Assume profile/account name is User.
Anyway, there is another problem with VLC that I've encountered, is changes to the option "repeat all" don't get saved in OS X Yosemite. And after this code opens up VLC, VLC doesn't get closed. It just keeps on repeating..., most likely because option "repeat all" is always checked.

Anyway, is there a way to take still frames, but without displaying the video or with a slower playback speed? I feel like it would be a smarter way to take still frames.