Lucent sued Microsoft a couple of years ago over their U.S. patent 5,227,878 for a method for “Adaptive coding and decoding of frames and fields of video”. The first case was thrown out in 2005 because the patent contained a typo. This was corrected and now Lucent is at it again suing Microsoft for technology contained in the Xbox 360.
The technology is beyond me, but it seems like the claim is for a coding and decoding algorithm that converts high-quality video at smaller bit rates without loss of quality. Yet another low qualityUSPTO patent? Who would have guessed?