DATA PROCESSING APPARATUS AND METHOD

An encoding data processing apparatus configured to parse a compression encoded bit stream to identify frames of a video image, and to determine for image frame areas of the compression encoded bit stream providing spare data capacity as a result of the fixed data portion not being completely filled with macroblocks; to first check within the macroblocks whether an additional amount of data required to represent the entire visible watermark can be accommodated in a memory space formed by the spare data capacity of the image frame; and after it has been determined that the additional data for representing the entire visible watermark can be accommodated within the spare data capacity, to change selected macroblocks of the image frame to represent the visible watermark; to generate a bit pattern representing the macroblocks in the original image frame which have changed to represent the visible watermark; and to insert all the additional data into the areas providing the spare data capacity of the fixed data portions of the image frame.