ON-SCREEN DISPLAY SCROLL APPARATUS

摘要

PURPOSE: A decoder to convert encoded video signal into an output video signal is to scroll the on-screen display of closed caption information included in the encoded video signal. CONSTITUTION: An on-screen display scroll apparatus decodes a closed caption information from an encoded video signal according to the lines of the on-screen display data. An on-screen display processor(170) stores in turns the successive groups of the lines of the order of the lines on a first and a second buffer which each of successive groups is moving. A display processor displays on-screen display data from the first and the second memory buffers synchronized with the stores of the buffers, and the group the most recently stored group of the lines is displayed according thereto. Instead of the using of the first and the second buffers, the lines of the on-screen display data on the linked list of the memory storage region. The on-screen display information stored in the linked list is transmitted to a picture processor(120) in order to get the on-screen display. In order to scroll the on-screen display, a memory region is added into one end of the linked list, and a memory region is separated from other end. The added memory region stores the successive lines of the on-screen display data from the order of the lines of the on-screen display data.