Patent ID: 6810388
Filing Date: 2004-10-26
Classification: G06F,G11B

Abstract:
A digital contents copying-inhibition apparatus comprising:a guard data storage section which stores guard data, the guard data being appendable to audio or video digital data, the audio or video digital data being expressable as an amplitude of a frequency component, and wherein a presence of the guard data becomes audibly apparent to a user only when the audio or video digital data is reproduced after the audio or video digital data with the guard data appended thereto has been compressed; a peak detection section which identifies a position of a digital value having a prespecified increase rate and a prespecified amplitude among a plurality of digital values each constituting a portion of the digital data; a data analysis section which sets a flag for a digital value located at a position away from the peak position by a prespecified number and also sets a plurality of digital values within a prespecified range centering on the digital value for which the flag has been set as a data pattern; and a guard data appending section which identifies positions where the data pattern is located from the digital data and varies the digital data by appending the guard data to the identified positions, wherein the guard data is expressed as digital audio data with a small sound volume change rate and a high frequency, and the guard data is appended to a section of the digital data with a small sound volume immediately behind a portion with a large sound volume.