What is claimed is:
1. A digital contents distribution system comprising:
a digital contents distribution center that distributes digital contents;
at least one user terminal that receives said digital contents; and
an information transmission medium that interconnects said digital contents distribution center and said user terminal,
wherein said digital contents distribution center comprises:
link means for generating a first execution verify logic that carries out verification and execution control of said digital contents, and for linking said first execution verify logic with said digital contents; and
execution verify logic conversion software generating means for generating a second execution verify logic that carries out verification and execution control of said digital contents, and for generating execution verify logic conversion software for replacing said first execution verify logic linked to said digital contents with said second execution verify logic to form a new linkage of said digital contents and said second execution verify logic,
wherein said digital contents distribution center provides said user terminal with at least part of said execution verify logic conversion software and said digital contents linked with said first execution verify logic, via said information transmission medium.
2. The digital contents distribution system as claimed in claim 1, wherein said second execution verify logic has less severe execution restrictions than said first execution verify logic.
3. The digital contents distribution system as claimed in claim 1, wherein said digital contents distribution center provides said user terminal with all of said execution verify logic conversion software and said digital contents linked with said first execution verify logic, via a communication channel.
4. The digital contents distribution system as claimed in claim 1, wherein said link means comprises:
contents key generating means for generating a contents key for encrypting at least part of said digital contents;
contents encrypting means for encrypting at least part of said digital contents using said contents key generated by said contents key generating means;
digital watermarking means for inseparably incorporating predetermined information into said digital contents using digital watermarking;
digital signature generating means for generating a digital signature of said digital contents;
first identifier generating means for generating a hash value of said first execution verify logic as a first message identifier; and
contents link means for linking said digital signature, said first execution verify logic and said first message identifier with said digital contents which have been encrypted at least in part by said contents encrypting means, and undergone digital watermarking by said digital watermarking means.
5. The digital contents distribution system as claimed in claim 4, wherein said execution verify logic conversion software generating means comprises:
encrypted contents management means for managing, in connection with said contents key, said first message identifier of said digital contents encrypted by said contents encrypting means;
second identifier generating means for generating a hash value of said second execution verify logic as a second message identifier;
second execution verify logic generating means for generating said second execution verify logic in accordance with its specifications transmitted from said digital contents distribution center; and
conversion software generating means for generating execution verify logic conversion software for replacing said first execution verify logic with said second execution verify logic generated by said second execution verify logic generating means.
6. The digital contents distribution system as claimed in claim 5, wherein said second execution verify logic comprises:
digital signature verify means for verifying digital signature of said digital contents;
identifier verify means for verifying said second message identifier;
contents key storage means for storing said contents key;
contents key storage decision means for making a decision whether said contents key is stored in said contents key storage means; and
decrypting means for decrypting, using said contents key, said digital contents which have been encrypted, when said contents key is stored in said contents key storage means.
7. The digital contents distribution system as claimed in claim 6, wherein said contents key storage means stores said contents key which has been encrypted using a public key of a user to whom said digital contents are to be distributed.
8. The digital contents distribution system as claimed in claim 7, wherein said second execution verify logic comprises private key acquisition means for acquiring a private key of said user, and wherein said decrypting means decrypts, using said private key of said user, said contents key stored in said contents key storage means, and decrypts, using said contents key decrypted, said digital contents encrypted by said contents encrypting means.
9. The digital contents distribution system as claimed in claim 1, wherein said execution verify logic conversion software comprises user information embedding means for embedding user information into said digital contents using digital watermarking.
10. The digital contents distribution system as claimed in claim 1, wherein said execution verify logic conversion software comprises charge information providing means for transmitting charge information to said digital contents distribution center via said information transmission medium, when said first execution verify logic is changed to said second execution verify logic.
11. A digital contents distribution system comprising:
an author terminal of an author who creates digital contents;
a copyright management agency, serving as a deputy of the author, for carrying out copyright management of said digital contents said author creates;
a digital contents distribution center that distributes said digital contents;
at least one user terminal that receives said digital contents; and
an information transmission medium that interconnects said author terminal, said copyright management agency, said digital contents distribution center and said user terminal,
wherein said author terminal comprises link means for generating first execution verify logic that carries out verification and execution control of said digital contents, and for linking said first execution verify logic with said digital contents,
wherein said copyright management agency comprises execution verify logic conversion software generating means for generating a second execution verify logic in accordance with specifications of said second execution verify logic transmitted from said digital contents distribution center, and for generating execution verify logic conversion software for replacing said first execution verify logic with said second execution verify logic, and
wherein said digital contents distribution center comprises specifications generating means for generating said specifications of said second execution verify logic, and compare and verify means for comparing said second execution verify logic, which is included in said execution verify logic conversion software transmitted from said copyright management agency, with said specifications of said second execution verify logic, which are generated in said digital contents distribution center, to verify said second execution verify logic, and wherein said digital contents distribution center provides said user terminal with at least part of said execution verify logic conversion software and said digital contents linked with said first execution verify logic, via said information transmission medium.
12. The digital contents distribution system as claimed in claim 11, wherein said second execution verify logic has less severe execution restrictions than said first execution verify logic.
13. The digital contents distribution system as claimed in claim 11, wherein said digital contents distribution center provides said user terminal with said execution verify logic conversion software and said digital contents linked with said first execution verify logic, via a communication channel.
14. The digital contents distribution system as claimed in claim 11, wherein said link means comprises:
contents key generating means for generating a contents key for encrypting at least part of said digital contents;
contents encrypting means for encrypting at least part of said digital contents using said contents key generated by said contents key generating means;
digital watermarking means for inseparably incorporating predetermined information into said digital contents using digital watermarking;
digital signature generating means for generating a digital signature of said digital contents;
first identifier generating means for generating a hash value of said first execution verify logic as a first message identifier; and
contents link means for linking said digital signature, said first execution verify logic and said first message identifier with said digital contents which have been encrypted at least in part by said contents encrypting means, and undergone digital watermarking by said digital watermarking means.
15. The digital contents distribution system as claimed in claim 14, wherein said execution verify logic conversion software generating means comprises:
encrypted contents management means for managing, in connection with said contents key, said first message identifier of said digital contents encrypted by said contents encrypting means;
second identifier generating means for generating a hash value of said second execution verify logic as a second message identifier; and
second execution verify logic generating means for generating said second execution verify logic in accordance with its specifications transmitted from said digital contents distribution center; and
conversion software generating means for generating execution verify logic conversion software for replacing said first execution verify logic with said second execution verify logic generated by said second execution verify logic generating means.
16. The digital contents distribution system as claimed in claim 15, wherein said second execution verify logic comprises:
digital signature verify means for verifying digital signature of said digital contents;
identifier verify means for verifying said second message identifier;
contents key storage means for storing said contents key;
contents key storage decision means for making a decision whether said contents key is stored in said contents key storage means; and
decrypting means for decrypting, using said contents key, said digital contents which have been encrypted, when said contents key is stored in said contents key storage means.
17. The digital contents distribution system as claimed in claim 16, wherein said contents key storage means stores said contents key which has been encrypted using a public key of a user to whom said digital contents are to be distributed.
18. The digital contents distribution system as claimed in claim 17, wherein said second execution verify logic comprises private key acquisition means for acquiring a private key of said user, and wherein said decrypting means decrypts, using said private key of said user, said contents key stored in said contents key storage means, and decrypts, using said contents key decrypted, said digital contents encrypted by said contents encrypting means.
19. The digital contents distribution system as claimed in claim 11, wherein said execution verify logic conversion software comprises user information embedding means for embedding user information into said digital contents using digital watermarking.
20. The digital contents distribution system as claimed in claim 11, wherein said execution verify logic conversion software comprises charge information providing means for transmitting charge information to said digital contents distribution center via said information transmission medium, when said first execution verify logic is changed to said second execution verify logic.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for fast forwarding digital video processed by a digital video player, comprising:
receiving an encoded digital video stream comprising at least one I frame, at least one P frame, and at least one B frame;
determining a set of frames for displaying on a display unit of the digital video player based on a data size of each frame present in the encoded digital video stream;
decoding each one of the at least one I frame and the at least one P frame;
decoding each one of the at least one B frame only if the each one of the at least one B frame belongs to the set of frames; and
forwarding decoded frames of the set of frames for the displaying on the display unit.
2. The method of claim 1, wherein the receiving the encoded digital video stream further comprises identifying a frame type of the each frame present in the encoded digital video stream.
3. The method of claim 1, wherein the determining the set of frames further comprises sorting the at least one I frame, the at least one P frame, and the at least one B frame based on the data size of the each frame present in the encoded digital video stream.
4. The method of claim 3, wherein a number of the set of frames for the displaying is configured based on a command signal.
5. The method of claim 1, wherein the data size of the each frame present in the encoded digital video stream is determined based on a number of bits in the each frame.
6. The method of claim 5, wherein the number of bits in the each frame of the at least one P frame and the at least one B frame indicates a degree of content change in the each frame of the at least one P frame and the at least one B frame from a respective reference frame.
7. The method of claim 1, wherein the encoded digital video stream is based on a video coding experts group (VCEG) standard.
8. The method of claim 1, wherein the encoded digital video stream is based on a moving picture experts group (MPEG) standard.
9. The method of claim 8, wherein the encoded digital video stream according to the MPEG standard comprises a group of pictures in a sequence of I frame, B frame, B frame, P frame, B frame, B frame, P frame, B frame, B frame, P frame, B frame, B frame, P frame, B frame, B frame, P frame.
10. The method of claim 1, wherein the set of frames for the displaying comprises the at least one I frame and a combination of the at least one P frame and the at least one B frame.
11. The method of claim 1, wherein the set of frames for the displaying comprises the at least one I frame and a subset of the at least one P frame.
12. The method of claim 1, wherein the set of frames for the displaying comprises the at least one I frame and a subset of the at least one B frame.
13. The method of claim 1, wherein the decoded frames of the set of frames for the displaying are reconstructed based on their respective orders in the encoded digital video stream.
14. A method for fast forwarding digital video processed by a digital video player, comprising:
receiving an encoded digital video stream comprising at least one I frame, at least one P frame, and at least one B frame;
identifying a group of frames for displaying on a display unit coupled to the digital video player from the at least one P frame and the at least one B frame based on a data size of each frame of the at least one P frame and the at least one B frame;
decoding each one of the at least one I frame and the at least one P frame;
decoding each one of the at least one B frame only if the each one of the at least one B frame belongs to the group of frames for the displaying; and
forwarding decoded frames of the at least one I frame and the group of frames for the displaying on the display unit.
15. The method of claim 14, wherein the data size of the each frame of the at least one P frame and the at least one B frame is determined based on a number of bits in the each frame.
16. The method of claim 15, wherein the number of bits in the each frame of the at least one P frame and the at least one B frame indicates a degree of content change in the each frame of the at least one P frame and the at least one B frame from a respective reference frame.
17. The method of claim 14, wherein the determining the group of frames further comprises sorting the at least one I frame, the at least one P frame, and the at least one B frame based on the data size of the each frame.
18. The method of claim 14, wherein the decoded frames of the at least one I frame and the group of frames for the displaying are reconstructed based on their respective orders in the encoded digital video stream.
19. A digital video player, comprising:
a fast forward module, comprising:
a decoder module;
a processor; and
a memory comprising a set of instructions, when executed by the processor and the decoder module, executes a method comprising:
receiving an encoded digital video stream comprising at least one I frame, at least one P frame, and at least one B frame;
determining a set of frames for displaying on a display unit of the digital video player based on a data size of each frame present in the encoded digital video stream;
decoding each one of the at least one I frame and the at least one P frame;
decoding each one of the at least one B frame only if the each one of the at least one B frame belongs to the set of frames; and
forwarding decoded frames of the set of frames for the displaying on the display unit.
20. The digital video player of claim 19, wherein the display unit comprises a television screen and a computer screen.