Abstract: A system is disclosed for detecting the recording data of a video tape recorder, which is enabled to detect data concerning the time and channel a program played back was recorded at and through, by adding both calendar data such as the date and time and channel data indicating a channel to be recorded in the recording operation of the video tape recorder and by extracting the above-specified data in the playback operation.

Abstract: A system which detects the operation of a video tape recorder to obtain data related to the operation of the video tape recorder. The system is also capable of determining the dubbing condition of the video tape recorder over the recording of an ordinary broadcast. The system further determines the receiving channel of the video tape recorder or the television set by directly comparing video signals.

Abstract: The invention relates to an audience rating measuring system for a television and a video tape recorder and provides an audience rating measuring system which can give accurate audience data under various conditions, such as when a television and a video tape recorder are used in combination, that can not be measured by the conventional audience rating measuring systems in general use. The audience rating measuring system of the invention comprises means for video tape recorder channel discrimination, video tape recorder operation mode discrimination, and television channel discrimination.