• Journal of KIISE:Computing Practices and Letters
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• v.16 no.6
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• pp.737-741
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• 2010

When implementing Enhanced TV services, the time synchronization between the video stream that forms the background and the data contents overlaid on audio/video is an important issue. Currently, however, the basic method of synchronizing the data in the MPEG-4 environment is based on absolute time values. For more efficient synchronization when developing Enhanced TV content, this paper proposes a content-based synchronization in which the data content varies depending on the video content. The proposed content-based synchronization method is implemented by defining BIFS nodes more widely, based on scene keywords, and then using the metadata of MPEG7.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10b
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• pp.211-213
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• 2001

본 논문에서는 서버와 클라이언트로 구성되는 분산환경에서 MPEG-4 데이터의 동기화를 제어하기 위한 방법과 그러한 방법으로 실제 구현이 된 MPEG-4 재생기를 소개한다. 데이터를 전송할 때 멀티 채널을 사용할 경우 얻을 수 있는 장점을 이용하기 위해서 서버측에서 MPEG-4 데이터를 디먹싱하여 비디오 부분과 오디오 부분을 분리해서 두 개의 채널로 클라이언트로 전송하며. 클라이언트는 이 데이터를 디코딩 타임 스템프(DTS)를 이용해서 화면상에 동기화를 구현하게 된다. MPEG 표준에서는 디코딩 타임 스템프(DTS)와 프리젠테이션 타임 스템프(PTS)를 정의하고 있는데, 본 논문에서는 DTS만으로 동기화를 구현을 한으로써 사용자 인터페이스 상의 재생 효율을 보장을 하면서 동시에 자원의 사용을 줄여 시스템 오버헤드를 줄일 수 있다. 이러한 방식은 무선환경에서의 멀티미디어 재생에 응용할 수 있을 것이다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.1B
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• pp.117-124
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• 2004

With MPEG-4 3D mesh coding(3DMC), the problem of the need of a wide bandwidth can be solved to store and transmit 3D information because of its high compression rate. And to realize the 3D information service with broadcasting or internet, one needs to transmit not only the 3D contents but also the 3D player. Therefore, in this paper we implement a 3D player based on MPEG-4 using a java language. A well-known java language employed in this paper provides the player with a wider range of applications, for example, when the O/S or the platform are different, due to its properties of scalability and universality. The implemented player which has functions (translation, rotation, etc) that can manipulate contents decodes the 3D contents and displays them. In addition, the player has a network function that receives a 3D content from the server. This paper explains the architecture and characteristics of the player and shows its simulation results.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.595-598
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• 2005

MPEG-4 Visual is, and international standard for the object-based video compression, designed for supporting a wide range of applications from multimedia communication to HDTV. To control the minimum decoding complexity required at the decoder, the MPEG-4 Visual standard defines the co-called video buffering mechanism, which includes three video buffer models. Among them, the VCV(Video Complexity Verifier) defines the control of the processing speed for decoding of a macroblock, there are two models: VCV and B-VCV distinguishing the boundary and non-boundary MB. This paper presents the evaluation results of decoding complexity by measuring decoding time of a MB for rectangular, arbitrarily shaped video objects and the various types of objects supporting the resolution of HDTV using the optimized MPEG-4 Reference Software. The experimental results shows that decoding complexity varies depending on the coding type and more effective usage of decoding resources may be possible.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.6C
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• pp.624-633
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• 2003

We propose a novel method of selecting key VOPs from MPEG-4 compressed domain without fully decoding the compressed data. Approximated shapes of VOPs are obtained from the shape coding mode and then VOPs are clustered by shape similarity to generate key VOPs. The proposed method reduces the computation time of shape approximation, compared with Erol's method. Nevertheless, the resulting VOPs have a good summarizing capability of a video sequence. NMHD (normalized mean Hausdorff distance) values are 2-means clustered to generate key VOPs. In the video search, the MHD of a query VOP from key VOPs are computed and the VOP with the lowest distance is returned. Tests on standard MPEG-4 test sequences show that the computational complexity is very low. Recursive clustering proved to be very effective for generating suitable key VOPs.

• Journal of Korea Society of Industrial Information Systems
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• v.11 no.3
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• pp.69-81
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• 2006

In this paper, an adaptive algorithm is proposed in streaming MPEG-4 contents with fluctuating resource amount such as throughput of network conditions. In the area of adaptive streaming issue, a lot of researches have been made on how to represent encoded media(such as video) bitstream in scalable way. By contrast, MPEG-4 supports object-based multimedia content which is composed of various types of media streams such as audio, video, image and other graphical elements. Thus, it can be more effective to provide individual media streams in scalable way for streaming object-based content to heterogeneous environment. The proposed method provides the multiple media streams corresponding to an object with different qualities and bit rate in order to support object based scalability to the MPEG-4 content. In addition, an optimal selection of the multiple streams for each object to meet a given constraint is proposed. The selection process is adopted a multiple choice knapsack problem with multi-step selection for the MPEG-4 objects with different scalability levels. The proposed algorithm enforces the optimal selection process to maintain the perceptual qualities of more important objects at the best effort. The experimental results show that the set of selected media stream for presenting objects meets a current transmission condition with more high perceptual quality.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.9C
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• pp.697-703
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• 2008

The H.264/AVC video coding standard provides higher coding efnciency compared to the conventional MPEG-2 standard. Since a lot of videos have been encoded using MPEG-2, the format conversion from MPEG-2 to H.264 is essential. In this paper, we propose an efficient method for the conversion of DCT coefficients to H.264/AVC transform coefficients. This conversion is essential, since $8{\times}8$ DCT and $4{\times}4$ integer transform are used in MPEG-2 and H.264/AVC, respectively. The mathematical analysis and computer simulation show that the computational complexity of the proposed algorithm is reduced compared to the conventional algorithm, while the loss caused by the conversion is negligible.

• Electronics and Telecommunications Trends
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• v.19 no.4 s.88
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• pp.63-73
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• 2004

최근 디지털 콘텐츠 산업에서의 저작권 보호 시스템에 대한 중요성이 강조되면서 상호 연동 가능한 DRM에 대한 연구가 활발히 진행되고 있다. MPEG-2/4 IPMPX는 이러한 요구조건을 만족시키기 위하여 시작된 대표적인 국제표준으로 현재 그 규격이 완성단계에 있다. 본 고에서는 기존의 폐쇄 프레임워크형 DRM 시스템 구조에서 탈피하여 개방 프레임워크형 기반의 DRM 플랫폼을 제시한 MPEG-2/4 IPMPX의 기술내용과 구현사례에 대하여 살펴보고 앞으로 해결해야 할 문제점을 제시하였다. 또한 관련 기술동향에 대하여도 간단히 언급하였다.

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.851-854
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• 2003

The low power motion estimation for MPEG-4 is a soft-core for hardwired motion estimation block in MPEG-4. This motion estimation is modified by 10 difference mode. So, this motion estimation decrease a power consumption compare conventional step search. This modified 4SS Low power Motion Estimation has been tested and verified to be valid for implementation of FPGA. The average PSNR between the original image and the motion-compensated image is 28.25dB. And Power consumption is 26mW.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.564-568
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• 1999

In this paper, we will show the brief technical specification of HPEG-4 International Standard that is reached at the final stage and the movement of multimedia industry according to it. As a result of MPEG-4 standardization activities, we would like to give you our opinion on the use of the MPEG-4 technologies for the coming information society in near future.