I found a faded post-it note from a friend who gave me the following
incantation to convert a set of still images into an MPEG animation using
ffmpeg. This note is a crumb for later investigation.
ffmpeg -r1 -f image2 -i <input> -vcodec mpg2video \ -r 30000/1001 -b 25000k <outMovie.mpg>
If memory serves, the 30000/1001 may need to be changed to the decimal value, but I'll see if ffmpeg will parse and calculate on its own ;-)