Abstract: A video data recording/reproducing apparatus is designed to effect the high density recording for low bit rate coded data, correct the error with high reliability and reproduce only the main signal. For this purpose, an error correction circuit corrects the error in a transmission path by use of a parity code added by a parity adding circuit on the transmission side. A switch selects one of outputs of the parity adding circuit and error correction circuit according to whether the parity code is contained in the transmission data or not. A recording/reproducing circuit causes an output of the switch to be recorded. At the time of reproducing operation, the error correction circuit corrects the error in the recording/reproducing operation by use of the parity code contained in the reproduced signal.

Abstract: The present invention provides an apparatus and method for sensing the contamination level in an optical storage device and for issuing a signal when the contamination exceeds a predetermined value relative to a base value. The tracking error signal gain of an optical drive is monitored and compared with a base gain. An alert signal is then generated if the actual measured gain exceeds a predetermined level relative to the base gain, whereupon a cleaning device can be mounted in the storage device and optical elements cleaned.