Graphics display system with anti-flutter filtering and vertical scaling feature

Abstract

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.

1 - 14 . (canceled) 
   
   
       15 . A method of performing anti-flutter filtering and graphics scaling comprising the steps of:
 providing a plurality of display lines to a graphics filter; and   performing graphics scaling and anti-flutter filtering simultaneously using the graphics filter.