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/