MagicFilter

magicfilter is an extensible and customizable automatic printer filter.
It selects an appropriate conversion technique for the input data by
seeking for magic numbers, and then utilizing the appropriate conversion
utility.

magicfilter is primarily intended for use as the `input filter' by the
lpd print spooler. The options accepted by magicfilter are exactly the
ones passed to the input filter by lpd (unless you build it on a LPRng
system -- in that case, magicfilter accepts no options.)

WWW: http://www.pell.portland.or.us/~orc/Code/magicfilter/