• Journal of KIISE:Software and Applications
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• v.31 no.12
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• pp.1611-1620
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• 2004

MPEG-4 supports dynamic scene composition through add/delete/replace of object or change of object's properties. Other existing MPEG-4 players focus on transmitting and playing the multimedia data according to MPEG-4 standard. It is insufficient for MPEG-4's characteristic such as playback of various objects and playback of dynamic scene composition. In this paper, we propose an effective scene compositor which is the core component of MPEG-4 player The scene compositor is an optimized processor that searches efficiently the scene graph, creates the data structure for independent management of object information and improves processing ability of user interaction. The scene compositor supports sufficiently scene description information, and is managed independently in player for component extension and application of mobile environment.

• Journal of KIISE:Computing Practices and Letters
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• v.11 no.2
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• pp.124-132
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• 2005

We propose a method using a transformation of an object and a scene tree in order to author MPEG-4 contents for mobile devices in this paper. The method transforms media objects in the scene into geometry objects in order to reduce initial loading time of the contents, and reduces an external form of each object in a scene of the content for presenting it efficiently on the small interface of mobile devices. Therefore, the contents for mobile devices are reconstructed by the method. An original object in the scene is presented on a mobile device when a user clicks a related geometry object. The method was applied to a conventional authoring tool, so we could find that the method showed an efficient presentation of MPEG-4 contents on mobile devices.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.2
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• pp.182-190
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• 2003

For temporal relations of interactive media such as MPEG-4, it is necessary for a temporal model that can update dynamically presentation time and temporal relations among objects by user events occurring during playback. Also, 811hough the temporal attributes are changed by user events, the validity of scene must be maintained. In this paper, we propose a temporal model that supports user interaction and developed an MPES-4 contents authoring system applying this model. We define the temporal relations of MPEG-4 that tan be authored and user interactions that can change the temporal properties. This authoring system defines the constraints on temporal relations and events and can generate the scene without error by checking the constraints. Also it provides the authoring environment to author visual]y temporal relations and events in MPEG-4 scene and generates the MPEG-4 stream by encoding the authored scene.

• Proceedings of the Korea Multimedia Society Conference
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• 2001.06a
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• pp.192-195
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• 2001

MPEG-4 content is streaming media that are composed of different types of media objects, organized in a hierarchical fashion. This paper proposes scene composition model for authoring MPEG-4 contents which can support object based interactions. And we have developed MPEG-4 contents authoring tool applied the proposed scene composition model as intermediate data structure. Particularly, for supporting interoperability between multimedia contents, the scene composition model should be used independent of file format. So visual scene composed of media objects on the from of scene composition tree can be transformed variable data format including BIFS, scene description from proposed by MPEG-4 standard and also support the extension of capability.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.1
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• pp.54-60
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• 2007

The Digital Multimedia Broadcasting(DMB) system is developed to offer high quality multimedia content to the mobile environment. The system adopts the MPEG-4 standard for the main video, audio and other media format. For providing interactive contents, it also adopts the MPEG-4 scene description that refers to the spatio-temporal specifications and behaviors of individual objects. With more interactive contents, the scene description also needs higher bitrate. However, the bandwidth for allocating meta data, such as scene description is restrictive in the mobile environment. On one hand, the DMB terminal renders each media stream according to the scene description. Thus the binary format for scene(BIFS) stream corresponding to the scene description should be decoded and parsed in advance when presenting media data. With this reasoning, the transmission delay of the BIFS stream would cause the delay in transmitting whole audio-visual scene presentations, although the audio or video streams are encoded in very low bitrate. This paper presents the effective optimization technique in adapting the BIFS stream into the expected bitrate without any waste in bandwidth and avoiding transmission delays inthe initial scene description for interactive DMB content.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.966-969
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• 2006

Interactive DMB contents are provided by MPEG-4 scene description. The abundant interactions of the user bring on the high bit rate of MPEG-4 scene description. But DMB system has low bandwidth and limited bit rate. So we need new authoring method for MPEG-4 scene description. In this paper, we proposed a seamless authoring method for the DMB environment. It can generate BIFS information tinily and dynamically. The research result can be used by DMB system for a seamless MPEG-4 contents transmission.

• The Transactions of the Korea Information Processing Society
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• v.6 no.4
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• pp.868-876
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• 1999

In this paper, an efficient automatic video parsing technique on MPEG-compressed video that is fundamental for content-based indexing is described. The proposed method detects scene changes, regardless of IPB picture composition. To detect abrupt changes, the difference measure based on the dc coefficient in I picture and the macroblock reference feature in P and B pictures are utilized. For gradual scene changes, we use the macroblock reference information in P and B pictures. the process of scene change detection can be efficiently handled by extracting necessary data without full decoding of MPEG sequence. The performance of the proposed algorithm is analyzed based on precision and recall. the experimental results verified the effectiveness of the method for detecting scene changes of various MPEG sequences.

• Journal of the Korea Society of Computer and Information
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• v.4 no.3
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• pp.28-34
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• 1999

In this paper. we propose the method of Scene Change Detection for video sequence using the DC components and the moving vectors in the Macro Blocks in the DCT blocks. The proposed method detects the Scene Change which would not be related with the specific sequences in the compressed MPEG domain. To do this. we define new metrics for Scene Change Detection using the features of picture component and detect the exact Scene Change point of B-pictures using the characteristics of B-picture's sharp response for the moving vectors. In brief, we will detect the cut point using I-picture and the gradual scene changes such as dissolve, fade, wipe, etc. As a results, our proposed method shows good test results for the various MPEG sequences.

• Journal of Broadcast Engineering
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• v.11 no.3 s.32
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• pp.363-378
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• 2006

The Digital Multimedia Broadcasting(DMB) system is developed to offer high quality audio-visual multimedia contents to the mobile environment. The system adopts MPEG-4 standard for the main video, audio and other media format. It also adopts the MPEG-4 scene description for interactive multimedia contents. The animated and interactive contents can be actualized by BIFS(Binary Format for Scene), the binary format for scene description that refers to the spatio-temporal specifications and behaviors of the individual objects. As more interactive contents are, the scene description is also needed more high bitrate. However, the bandwidth for allocating meta data such as scene description is restrictive in mobile environment. On one hand, the DMB terminal starts demultiplexing content and decodes individual media by its own decoder. After decoding each media, rendering module presents each media stream according to the scene description. Thus the BIFS stream corresponding to the scene description should be decoded and parsed in advance of presenting media data. With these reason, the transmission delay of BIFS stream causes the delay of whole audio-visual scene presentation although the audio or video streams are encoded in very low bitrate. This paper presents the effective optimization technique for adapting BIFS stream into expected MPEG-2 TS bitrate without any bandwidth waste and avoiding the transmission delay of the initial scene description for interactive DMB contents.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.5
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• pp.25-33
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• 2010

Multi-media service has been changed into user based audio services, which service supports actively user's preference and interaction with the users. In the market, multi-media products which can support the highest audio-quality by using lossless audio technology have been released and object audio music which user can select the objects has been serviced. In this paper, we design user's preference information based object audio file format and audio scene description for storage and transmission media. The designed file format is designed based on MPEG-4 file format because high-quality audio codecs in MPEG-4 audio can be easily used and the track of file format can be flexibly controlled depend on the number of the instrument in music. The encoded audio data of each objects and encoded audio scene description by binary encoding that has independent track are packed in a file. The scene description for storage media is consist of full and object scene description, the scene description for transmission media has an essential description for object audio operation and a specific description for real audio sound. The designed file format based simulator is developed and it generates an object audio file with several scene descriptions. Also, the real audio sound is serviced by the interaction with user and the unpacked scene description.