PICTURE DECODER FOR PREVENTING JITTER IN FAST-PLAY MODES OF OPERATION

A picture decoder which prevents picture jitter when operating in a fast play mode. The picture decoder has a picture jitter preventing apparatus, which includes a picture coding extension region detector for detecting a picture coding extension region from picture data coded according to the MPEG2 standard, information region detector for detecting a region having top.sub.-- field.sub.-- first and repeat.sub.-- first.sub.-- field information from the detected picture coding extension region signal, and an information converter for converting values of top.sub.-- field.sub.-- first and repeat.sub.-- first.sub.-- field into 1 and 0, respectively, when in the fast play mode, and outputting the picture data free of jitter.