Extract single frame from mpeg2

[J. K. Cliburn]

J. K. Cliburn wrote:
> Can Xine or Mplayer be paused and coaxed into extracting a single frame 
> from an mpeg2 file and saving it as, say, a jpeg (or png, or gif)?  If 
> not, can someone recommend something that can?

Sometimes all it takes is to ask a question to focus the mind toward the 
answer.

mplayer -vo jpeg /path/to/mpeg2

Doesn't do *quite* what I was looking for, but it's close enough.