VIDEO SIGNAL PROCESSING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a video signal processing apparatus capable of obtaining stable display without causing a cost increase even when the video signal processing apparatus receives a nonstandard input video signal. SOLUTION: The video signal processing apparatus includes: an A-D converter 1 for receiving the input video signal, applying A-D conversion to the video signal and providing an output of video data; a synchronizing separator circuit 7 for separating a vertical synchronizing signal and a horizontal synchronizing signal included in the video data; a clock generating circuit 10 for generating a write clock synchronously with the horizontal synchronizing signal and a read clock synchronously with or asynchronously with the horizontal synchronizing signal; a nonstandard discrimination circuit 13 for discriminating the standard and nonstandard of the input video signal providing the vertical synchronizing signal and the horizontal synchronizing signal so as to discriminate the standard and nonstandard of the input video signal; a memory 4 from and to which the video data are read and written; a write control circuit 8 for generating a write start signal synchronously with the vertical synchronizing signal and controlling the timing of a write start of the video data; and a read control circuit 9 that controls the timing of read start of the video data signal according to the read start signal synchronously with the vertical synchronizing signal when the input video signal is the standard signal or controls the timing according to the read start signal asynchronously with the vertical synchronizing signal when the input video signal is the nonstandard signal. COPYRIGHT: (C)2006,JPO&NCIPI