Abstract: During recording of a television signal on a VCR, data are accumulated with respect to the time of occurrence and duration of detectable events, such as blank frames, in the television signal, and such data are stored. Timing reference data are written onto the tape as it is recorded. At a time subsequent to the recording process, the stored data are analyzed to classify the content of the television signal between the detectable events and a playback map is constructed for the recorded signal. During playback, the stored playback map is retrieved and stored timing data are compared to the timing reference data read from the tape. The VCR is automatically commanded into a fast scan mode when the tape reaches the beginning time of a portion of the video signal that has been classified for elimination during playback. The VCR is then automatically commanded to return to the normal "play" mode when the tape reaches the ending time of that portion of the video signal.

Abstract: A time code or other digital code is inserted into a video signal by modulating the video signal itself or the signal's radio frequency (RF) carrier. This allows the code to be recorded concurrently with recording of the video signal, thereby obviating the need for a specially adapted recording apparatus. Furthermore, since the code is embedded in the recorded video signal, the encoded information may be retrieved from the video signal in a unit that is external to the playback apparatus. In combination with a conventional video cassette recorder (VCR), the video signal that is tuned to by the VCR is processed to extract raster synchronization signals. A modulator inserted ahead of the RF input to the VCR modulates the RF carrier in response to the digital code. Feedback of the tuned video signal insures proper synchronization of the broadband RF modulation so that the digital code is inserted into a non-viewable portion of the recorded video signal.