A graphics integrated circuit chip is used in a set-top box for
controlling a television display. The graphics chip processes analog
video input, digital video input, and graphics input. The chip includes a
single polyphase filter that preferably provides both anti-flutter
filtering and scaling of graphics. Anti-flutter filtering may help reduce
display flicker due to the interlaced nature of television displays. The
scaling of graphics may be used to convert the normally square pixel
aspect ratio of graphics to the normally rectangular pixel aspect ratio
of video.