Abstract: Provided is a Simple Aggregation Format (SAF) synchronization packet structure including a SAF synchronization packet header and a SAF synchronization packet payload and multiplexing diverse element streams which include a scene description elementary stream. The SAF synchronization packet header includes time information related to an access unit included in the SAF synchronization packet payload, and the SAF synchronization packet payload includes header information on the access unit and payload information indicating the access unit. Since the present invention can multiplex diverse elementary streams effectively and simply into one data stream, synchronized data transmission is possible. Since the present invention accommodates a synchronization layer packet of the MPEG-4 system, it can be easily integrated with the MPEG-4 system and utilize the advantage of the MPEG-4 synchronization layer packet such as the concept of an access unit or a degradation priority.

Abstract: Provided are a method and apparatus for enabling a main stream to refer to an elementary stream existing in another simple aggregation format (SAF) session by using a global ID during provision of a light application scene representation (LASeR) service, and a LASeR service providing apparatus. In order for a main stream to refer to an elementary stream included in an SAF session different from an SAF session in which the main stream is included without a change of existing LASeR and SAF stream structures, the main stream for a LASeR service uses a global stream ID of the elementary stream as a reference value. Accordingly, the elementary stream included in the SAF session different from the SAF session of the main stream can be effectively referred to without need to create a separate apparatus or change an existing apparatus even when a global ID included in a LASeR scene description is used as in the conventional art.

Abstract: Provided are an extended Simple Aggregation Format (SAF) packet to support voluminous media data and a method of generating the extended SAF packet. The extended SAF packet includes an SAF access unit including an SAF fragment unit obtained by dividing the voluminous media data into a data size suitable for transmission through an SAF packet and a field that provides information about the type of the SAF fragment unit, and an SAF packet header including a field that provides information about whether the SAF access unit carries the SAF fragment unit. Thus, it is indicated that the SAF packet carries the SAF fragment unit from information of the SAF packet header, and the type of the SAF fragment unit, a sequence number of the SAF fragment unit and a total access unit length from information of the SAF access unit.

Abstract: Provided are a method and an apparatus for selectively encoding/decoding point sequences to maximize bit efficiency of a lightweight application scene representation (LASeR) binary stream. The point sequence encoding method includes the steps of: for each point sequence, (a) selecting one of exponential-Golomb (EG) encoding and fixed length (FL) encoding schemes; (b) when the FL encoding scheme is selected, encoding the point sequence using the FL encoding scheme to generate a binary stream; and (c) when the EG encoding scheme is selected, encoding the point sequence using the EG encoding scheme to generate a binary stream. The binary stream includes a flag indicating which encoding scheme is selected and a parameter k, with which the EG encoding can be most effectively performed, when the EG encoding scheme is selected. According to the encoding method, LASeR point sequences can be efficiently encoded and, during a decoding process, a large overhead is not incurred to a decoder (terminal).

Abstract: Provided are an apparatus and method for describing and processing digital items using a scene representation language. The apparatus includes a digital item method engine (DIME) unit for executing components based on component information included in the digital item; and a scene representation unit for expressing scenes of a plural number of media data included in the digital item in a form of defining spatio-temporal relations and allowing the media data to interact with each other. The digital item includes scene representation having representation information of the scene, and calling information for the digital item express unit to execute the scene representation unit in order to represent the scene based on the scene representation information at the scene representation unit.

Abstract: Provided are a method and apparatus for displaying lightweight applications scene representation (LASeR) content. A LASeR markup language (ML) that is based on a LASeR binary stream or a LASeR extensible markup language (XML) is parsed so as to generate a LASeR document object model (DOM). A LASeR application program interface (API) is used to generate a LASeR DOM object tree. A LASeR player accesses the LASeR DOM to display LASeR DOM scene information.

Abstract: Provided is a Simple Aggregation Format (SAF) synchronization packet structure including a SAF synchronization packet header and a SAF synchronization packet payload and multiplexing diverse element streams which include a scene description elementary stream. The SAF synchronization packet header includes time information related to an access unit included in the SAF synchronization packet payload, and the SAF synchronization packet payload includes header information on the access unit and payload information indicating the access unit. Since the present invention can multiplex diverse elementary streams effectively and simply into one data stream, synchronized data transmission is possible. Since the present invention accommodates a synchronization layer packet of the MPEG-4 system, it can be easily integrated with the MPEG-4 system and utilize the advantage of the MPEG-4 synchronization layer packet such as the concept of an access unit or a degradation priority.

Abstract: Provided is an apparatus and method for converting contents. The apparatus includes: a contents input unit for receiving contents for digital television (DTV) broadcasting; a decompiling unit for analyzing a class file of the contents for DTV broadcasting transmitted from the contents input unit and creating common contents conversion information and contents conversion information; a contents converting unit for converting the contents for DTV broadcasting transmitted from the contents input unit based on the created common contents conversion information; and an eXtensible MPEG-4 Textual format (XMT) creating unit for applying the contents conversion information to a template file from outside and creating XMT.

Abstract: In a device for editing and authoring object-based AV (audio and visual) contents using the MPEG-4 method, an object-based MPEG-4 (moving picture experts group 4) contents editing and authoring device comprises: an extensible description generator for receiving either of an MPEG-4 textual format or internal data structure information of object-based MPEG-4 contents, and MPEG-7 (moving picture experts group 7) descriptions of the MPEG-4 contents, and generating an XML (extensible markup language) based textual format file including the MPEG-7 descriptions; an extensible description/binary converter for receiving the XML based textual format file including the MPEG-7 descriptions generated by the extensible description generator, and generating them as a binary file; and an XML based contents storage unit for storing the XML based textual format file generated by the extensible description generator and the binary file generated by the extensible description/binary converter.

Abstract: A system and method for providing a karaoke service using an object-oriented audio/video karaoke contents through a digital TV using a set-top box connected to a cable network or internet is disclosed. The system for providing a karaoke service using the set-top box, the system includes: a user management server for authenticating and managing a user accessing the karaoke service system to use object-oriented audio/video karaoke contents through a cable network or internet; and a contents service server for providing an object-oriented audio/video karaoke contents list to an authenticated user and karaoke contents selected by the authenticated user to a set-top box.