Abstract: Video data pieces are classified into groups according to prescribed rules. A cut number assigned to each of the groups is decided on the basis of the length or lengths of a video data piece or pieces in each of the groups and the number of the video data piece or pieces in each of the groups. A cut or cuts are extracted from the video data piece or pieces in each of the groups. Regarding each of the groups, the number of the extracted cut or cuts is equal to the decided cut number. Digest data is generated from the extracted cuts for all the groups.

Abstract: A feature analysis unit acquires feature data representing the features of each scene in image information. A group classification unit classifies a group composed of plural scenes to any one of a plurality of group types based on the feature data. A cut determination unit determines cuts from the scenes based on the importance calculated from the feature data using a formula corresponding to the group type of the group. A digest reproduction unit reproduces the cuts.

Abstract: Video data pieces are classified into groups according to prescribed rules. A cut number assigned to each of the groups is decided on the basis of the length or lengths of a video data piece or pieces in each of the groups and the number of the video data piece or pieces in each of the groups. A cut or cuts are extracted from the video data piece or pieces in each of the groups. Regarding each of the groups, the number of the extracted cut or cuts is equal to the decided cut number. Digest data is generated from the extracted cuts for all the groups.

Abstract: An in-scene digest segment number determining unit allocates the total number of cuts to be extracted as digest segments to each scene of digest creation objective scenes. A feature quantity detecting unit selects a plurality of representative frames from respective frames included in a cut extraction scene where the number of digest segments to be extracted is one or more and further detects a feature quantity of each representative frame. An importance calculating unit calculates the degree of importance of each representative frame, based on the feature quantities of each representative frame. A digest segment selecting unit determines a digest segment to be selected from each cut extraction scene, based on both feature quantities and importance degrees of representative frames in each cut extraction scene.

Abstract: Executes a re-encoding after decoding data of a connection section A of a first MPEG picture data. This re-encoding is executed based on a control such that a transition of a VBV buffer occupation value starts from a VBV buffer occupation value at a position a and ends with a VBV buffer occupation value at a position d. Up to the position a of the first MPEG picture data, the first MPEG picture data is reproduced. Next, re-encoded MPEG picture data of the connection section A is reproduced. Thereafter, the data is connected to the position d of a second MPEG picture data, and the second MPEG picture data of the position d and after is reproduced.

Abstract: Executes a re-encoding after decoding data of a connection section A of a first MPEG picture data. This re-encoding is executed based on a control such that a transition of a VBV buffer occupation value starts from a VBV buffer occupation value at a position a and ends with a VBV buffer occupation value at a position d. Up to the position a of the first MPEG picture data, the first MPEG picture data is reproduced. Next, re-encoded MPEG picture data of the connection section A is reproduced. Thereafter, the data is connected to the position d of a second MPEG picture data, and the second MPEG picture data of the position d and after is reproduced.

Abstract: An image data recording apparatus includes a menu picture data managing section and a recording section. The menu picture data managing section operates for managing first menu picture data containing control information designed to allow switching from reproduction of first image data pieces to reproduction of second image data pieces or switching from reproduction of the second image data pieces to reproduction of the first image data pieces. The recording section operates for obtaining the first menu picture data from the menu picture data managing section, and for recording the obtained first menu picture data, the first image data pieces, and the second image data pieces on a recording medium.

Abstract: Video data pieces are classified into groups according to prescribed rules. A cut number assigned to each of the groups is decided on the basis of the length or lengths of a video data piece or pieces in each of the groups and the number of the video data piece or pieces in each of the groups. A cut or cuts are extracted from the video data piece or pieces in each of the groups. Regarding each of the groups, the number of the extracted cut or cuts is equal to the decided cut number. Digest data is generated from the extracted cuts for all the groups.

Abstract: Main image data pieces in a recording medium are classified into groups according to recording date and time. A digest image data piece is generated from a main image data piece or pieces in each of the groups. Each of the generated digest image data pieces represents a digest of contents of the corresponding main image data piece or pieces. Contents of the digest image data pieces are sequentially reproduced in response to user's command in an order accorded with the recording dates and times of the main image data pieces corresponding to the digest image data pieces.

Abstract: Executes a re-encoding after decoding data of a connection section A of a first MPEG picture data. This re-encoding is executed based on a control such that a transition of a VBV buffer occupation value starts from a VBV buffer occupation value at a position a and ends with a VBV buffer occupation value at a position d. Up to the position a of the first MPEG picture data, the first MPEG picture data is reproduced. Next, re-encoded MPEG picture data of the connection section A is reproduced. Thereafter, the data is connected to the position d of a second MPEG picture data, and the second MPEG picture data of the position d and after is reproduced.

Abstract: Executes a re-encoding after decoding data of a connection section A of a first MPEG picture data. This re-encoding is executed based on a control such that a transition of a VBV buffer occupation value starts from a VBV buffer occupation value at a position a and ends with a VBV buffer occupation value at a position d. Up to the position a of the first MPEG picture data, the first MPEG picture data is reproduced. Next, re-encoded MPEG picture data of the connection section A is reproduced. Thereafter, the data is connected to the position d of a second MPEG picture data, and the second MPEG picture data of the position d and after is reproduced.

Abstract: An encryption key is generated in response to a plurality of information pieces being bases for the encryption key. Original information is encrypted into encryption-resultant information in response to the generated encryption key. The encryption-resultant information is divided into units. Each of the units is loaded with encryption control information for identifying the plurality of information pieces being the bases for the encryption key.

Abstract: Executes a re-encoding after decoding data of a connection section A of a first MPEG picture data. This re-encoding is executed based on a control such that a transition of a VBV buffer occupation value starts from a VBV buffer occupation value at a position a and ends with a VBV buffer occupation value at a position d. Up to the position a of the first MPEG picture data, the first MPEG picture data is reproduced. Next, re-encoded MPEG picture data of the connection section A is reproduced. Thereafter, the data is connected to the position d of a second MPEG picture data, and the second MPEG picture data of the position d and after is reproduced.

Abstract: An encryption key is generated in response to a plurality of information pieces being bases for the encryption key. Original information is encrypted into encryption-resultant information in response to the generated encryption key. The encryption-resultant information is divided into units. Each of the units is loaded with encryption control information for identifying the plurality of information pieces being the bases for the encryption key.

Abstract: A pseudorandom number generator (1) has a first linear feedback shift register (2), a second linear feedback shift register (3), an initial value generator (4), a polynomial coefficient generator (5), and a pseudorandom number output unit (6). The initial value generator (4) generates initial values and supplies the same to the first linear feedback shift register (2) and second linear feedback shift register (3). The polynomial coefficient generator (5) generates coefficients of a characteristic polynomial and supplies the same to the second linear feedback shift register (3). The pseudorandom number output unit (6) carries out exclusive-OR operations on bits sequentially provided by the first linear feedback shift register (2) and second linear feedback shift register (3), generates a pseudorandom number sequence, and outputs the same.

Abstract: The present invention relates to an encryption method for encrypting information including a series of multiple unit blocks, one at a time, a decryption method for decrypting multiple encrypted unit blocks, one at a time, and a recording and reproducing apparatus that uses those methods. The seed of an encryption key for encrypting each unit block and the seed of an encryption key for decrypting each encrypted unit block, which are used by those methods and the recording and reproducing apparatus, are based on a unit block that is one or more unit blocks before the current unit block in a reproduction order or on information generated by encrypting one or more unit blocks before the current unit block. Alternatively, the seed of an encryption key for encrypting each unit block and the seed of an encryption key for decrypting each encrypted unit block are information based on an encryption key for encrypting a unit block before the current unit block in a reproduction order.

Abstract: A recording apparatus generates key information based at least on contents reproduction permission information, encrypts contents based on the key information, and records the encrypted contents and recording date/time information on a recording medium. A reproducing apparatus reads the encrypted contents and the recording date/time information from the recording medium, acquires reproduction date/time information on the encrypted contents and, based on the recording date/time information that was read, the reproduction date/time information, and reproduction permission limit information on the encrypted contents, generates contents reproduction permission information indicating that the encrypted contents maybe reproduced. The reproducing apparatus generates key information based at least on the contents reproduction permission information and decrypts the encrypted contents that were read.

Abstract: A first-key signal representative of a first key is generated from first-key base information being a base of the first key. Contents information is encrypted into encryption-resultant contents information in response to the first-key signal. A second-key signal representative of a second key is generated on the basis of initial-value information of a given initial value according to a predetermined key generation algorithm. The first-key base information is encrypted into encryption-resultant first-key base information in response to the second-key signal. The encryption-resultant contents information, the encryption-resultant first-key base information, the initial-value information, and algorithm identification information for identifying the predetermined key generation algorithm are transmitted or recorded.

Abstract: Bits of a first bit sequence are rearranged in a first matrix according to a predetermined arrangement rule. The first bit sequence represents information being a base of a key. Blocks are formed in the first matrix. Each of the blocks has bits, the number of which is smaller than the number of bits composing the first matrix. Logical operation is executed among bits in each of the blocks, and a bit being a result of the logical operation is generated. The logical-operation-result bits are combined into a second bit sequence. The number of bits composing the second bit sequence is smaller than the number of bits composing the first bit sequence. There is a second matrix composed of predetermined third bit sequences. The second matrix is accessed and one is read out from among the third bit sequences in response to the second bit sequence. The read-out third bit sequence is outputted as information representative of the key.

Abstract: After a user terminal executes a data usage accounting procedure for a contents provider, enciphered copyrighted digital data generated by enciphering chargeable copyrighted digital data using encryption key data, digital sample preview data generated from an outline of the copyrighted digital data at a non-chargeable level without enciphering, decryption key data for deciphering the enciphered copyrighted digital data, and additional data required for accounting are transmitted from the contents provider to the user terminal over a network.