COPY PREVENTIVE METHOD OF CODED INFORMATION, ENCODIG DEVICE, DECODING DEVICE AND RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To make both the convenience of users and copyright protection compatible in the case of copying digital signals. SOLUTION: A high-quality digital signal A/D-converted by 24 bits is D/A- converted by a D/A converter 45 to output an analog signal through an output terminal 55. Dither noises are produced from a dither noise producer 57 to substantially limit 24 bits to e.g. 16 bits, added by an adder 56 and outputted through a digital output terminal 53. High-quality digital signals are added with the copyright data concerning their data to be outputted through a digital output terminal 90.