Method and apparatus for recording and playing back monitored video data

Abstract

A method and an apparatus for recording and playing back monitored video data for recording monitored video data generated continuously for a long time on a magnetic tape, with less S/N degradation by shortening the operation time of the VTR to suppress the degradation of the magnetic tape, recording head, and other mechanical items. Video signals from a video camera are converted to digital signals in an A/D converter, compressed and encoded in a compression encoder and decoder circuit, then transferred to a time axis compression circuit which includes a first memory, the second memory, an SCSI controller, and a hard disk unit. The digital signal is thereafter compressed on the time axis and recorded on the magnetic tape loaded in a D-VHS standard VTR via an I/F circuit. Compressing the video data from the compression encoder and decoder circuit on the time axis in the time axis compression circuit makes the recording time of the video data shorter on the magnetic tape than the actual recording time of the video camera. The VTR is only required to record video data intermittently on the magnetic tape and a general home VTR can be adopted as the above VTR, this also prevents the magnetic tape from being damaged.