5,227,878 pertains to MPEG-2 video decoding, used with DVDs.

In 2002, Lucent sued Dell and Gateway over several patents, including '878. Because Microsoft had indemnity agreements with those companies Lucent was going after, as the dispute was really over Windows software, Microsoft filed a countersuit against Lucent.

Although Microsoft got several patent infringement claims tossed on summary judgment in the first round, the fight over '878 was dismissed without prejudice because of a typographical error in '878: "compressed video bit stream" should have read "compressed digital video bit stream and fields of compressed video bit stream." "Dismissed without prejudice" means "live to fight another day." Having got a Certification of Correction from the patent office, Lucent sallies forth again with '878, this time directly at Microsoft.

Lucent sent Microsoft a heads-up nastygram before filing suit, as if that ever does any good. Going for a jury trial in sunny San Diego, Lucent seeks an injunction (who doesn't), and unspecified damages.