I made a script of this sort too originally called "ffmpeg-english" last year. Interesting how people reacted to it:

https://news.ycombinator.com/item?id=40410637

I then made a more general version of it for all commands:

https://github.com/dheera/scripts/blob/master/helpme

Example usage:

    $ helpme ffmpeg assemble all the .jpg files into an .mp4 timelapse video at 8fps