Abstract: An apparatus for a flexible and common IPMP System (Intellectual Property Management and Protection) offers flexibility and interoperability by incorporating a complete IPMP Tool List stored in the content stream or downloaded from a URL location. The IPMP Tool Manager of a compliant IPMP terminal functioning as a preprocessor module is provided, the IPMP Tool List is parsed, and an IPMP Tool is acquired based on the IPMP Tool ID, related location identifier, and IPMP Tool Format ID. The IPMP Tool can be precompiled to a binary format and sent or downloaded to the IPMP terminal, and different binary formats are prepared by the content provider for use on different IPMP terminal platforms.

Abstract: A method for appropriately defining standards for implementing an MPEG-n intellectual property management and protection (IPMP) system introduces IPMP Tool Information located at the beginning of the content stream, and an IPMP Tool management function as a pre-processing module located at the start of the content decoder, and retrieves IPMP Tools based on the IPMP Tool Information. To improve security and enable interoperability between terminals in different IPMP systems, a two-layer security structure and user authentication output format are further defined. Implementation on terminals of different complexity is enabled by further defining different profiles for IPMP Tool retrieval.

Abstract: An apparatus for a flexible and common IPMP System (Intellectual Property Management and Protection) offers flexibility and interoperability by incorporating a complete IPMP Tool List stored in the content stream or downloaded from a URL location. The IPMP Tool Manager of a compliant IPMP terminal functioning as a preprocessor module is provided, the IPMP Tool List is parsed, and an IPMP Tool is acquired based on the IPMP Tool ID, related location identifier, and IPMP Tool Format ID. The IPMP Tool can be precompiled to a binary format and sent or downloaded to the IPMP terminal, and different binary formats are prepared by the content provider for use on different IPMP terminal platforms.

Abstract: The contents distribution apparatus has a conversion section 9, composite key generation section 8, and adder 10. The conversion section 9 converts contents C to generate converted contents C/Nc using a contents identification number Nc previously allocated to the contents. The composite key generation section 8 generates a composite key from the contents identification number Nc, a storage identification number Ns, and a terminal key &agr; corresponding to the terminal. The adder 10 adds the composite key K generated by the composite key generation section 8 to the converted contents C/Nc generated by the conversion section 9 so as to generate added conversion contents C′.

Abstract: A method for appropriately defining standards for implementing an MPEG-n intellectual property management and protection (IPMP) system introduces IPMP Tool Information located at the beginning of the content stream, and an IPMP Tool management function as a pre-processing module located at the start of the content decoder, and retrieves IPMP Tools based on the IPMP Tool Information. To improve security and enable interoperability between terminals in different IPMP systems, a two-layer security structure and user authentication output format are further defined. Implementation on terminals of different complexity is enabled by further defining different profiles for IPMP Tool retrieval.

Abstract: In order to prevent distribution of an illegal copy of the content in the electronic distribution system, the method for controlling the distribution of content over the telecommunication network comprises steps of: adding apparatus identification information for identifying an apparatus by which the content is recorded and content identification information containing an identification code for identifying the content, to the content; transmitting the content to the telecommunication network; receiving at least one part of the content containing the apparatus identification information and the identification code over the telecommunication network; extracting the apparatus identification information and the identification code from the received at least one part of the content; judging whether the content is a legal copy or an illegal copy based on the apparatus identification information and the identification code extracted; and stopping reception and playback of the content when the content is judged an i

Abstract: A magnetic recording and reproducing apparatus for recording a signal on and reproducing it from a magnetic tape comprises an automatic A.C. bias adjusting device for increasing an A.C. bias current to be superimposed during recording of the signal at a predetermined rate and differentiating the reproduced signal by time to automatically establish an optimum A.C. bias, and a record compensation device for recording and reproducing an adjusting square wave, separating a fundamental frequency component of the square wave from a harmonic component, comprising both components to determine a ratio of them and adjusting a record compensation frequency characteristic in accordance with the ratio.

Abstract: A magnetic recording and reproducing apparatus for recording a signal on and reproducing it from a magnetic tape comprises an automatic A.C. bias adjusting device for increasing an A.C. bias current to be superimposed during recording of the signal at a predetermined rate and differentiating the reproduced signal by time to automatically establish an optimum A.C. bias, and a record compensation device for recording and reproducing an adjusting square wave, separating a fundamental frequency component of the square wave from a harmonic component, comprising both components to determine a ratio of them and adjusting a record compensation frequency characteristic in accordance with the ratio.

Abstract: A sound reproducing system for reproducing sounds from two loudspeakers located in front of a listener comprises a difference creating network for causing a ratio of sound pressures applied to left and right ears of the listener and causing a time difference between sound waves thereat by a sound radiated from a sound source located at any point around the listener, and a front and back recognizing network provided in common with both ears for cancelling information which causes the listener to feel that said loudspeakers are located in front of the listener and enabling the listener to localize a sound image at any point, whereby the listener can localize the sound image at any point around the listener while he is listening the sounds radiated from the two loudspeakers located in front of him.