You can take stills with Cyberlink Power DVD (the free trial is for 30 days, I think) and hold down C to get frame by frame captures. (Then you have to go through it frame by frame to delete duplicates.)
That's how this:
is possible.
You can also try using VirtualDub to automatically do it for you. It doesn't work for many formats though.
You can just pause the video and take screen captures, OSX will grab whatever is playing on the screen. Hitting shift-command-4 will allow you to select just the video player area and then it will save the files on the desktop.