A device enabling simultaneous recording and playback allows commercials to retain their advertisement function even if the commercials are skipped over during a playback process. By digital watermarking, CM-substitute data is embedded in program data among video signals broadcasted from a broadcast station. CM-substitute data is to present information such as a particular sponsor name and commodity name on display. The video recording/playback device includes a randomly accessible storage unit and has a simultaneous recording/playback capability. If commercial video is skipped over and is not rendered by playback, the CM-substitute information is superimposed on the rendered video of the program associated with the commercial. Thus, the commercial advertisement function can be retained.