METHOD FOR PROTECTION OF DATA DECODING ACCORDING TO MEDIUM PROTECTION DATA AND FIRST AND SECOND APPARATUS PROTECTION DATA TO DETERMINE A RANGE OF PROTECTION FOR MAIN DATA AND WHETHER SAID MAIN DATA ARE DECODED IN THEIR ENTIRETY, PARTIALLY, OR NOT AT ALL

摘要

In a reproduction apparatus, for reproducing an original signal conveyed as main data by a data medium such as a recording disk or broadcasting system, with medium protection data which are specific to the data medium being conveyed together with the main data, the apparatus includes a section for generating apparatus protection data which are specific to the reproduction apparatus, a section for combining the apparatus protection data with the medium protection data to define a protection level, and a section for applying the protection level to restrict reproduction of the original signal, with stepwise variations in restriction occurring in accordance with changes in protection level. The medium protection data may include information for specifying restricted reproduction of portions of the original signal, such as by producing degraded resolution within specified regions of specified frames of a video signal.