• Journal of the Korea Computer Industry Society
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• v.5 no.2
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• pp.293-300
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• 2004

In this paper, we devise both methods supporting interactive VCR-like functions for MPEG stream and minimizing the storage space. Specifically, we proposed both methods to efficiently stripe MPEG stream into multiple disks, and an access strategy to retrieve the distributed streams over the disks. To accurately locate the streams to be referred to, we introduce a table indexing the location. When client request Fast Forward(FF)/Fast Backward(FB), VOD(Video on Demand) server refer to this index table supporting FF/FB functions. Experimental result shows that the proposed method can reduce the additional storage space needed when VOD server services FF/FB functions.

• Journal of Broadcast Engineering
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• v.7 no.4
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• pp.355-361
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• 2002

In this paper, several methods which guarantee the seamless editing when the splicing is applied to the MPEG-2 system streams are described. In the MPEG-2 system standard, it is recommended that the splicing technique is applied in the Transport Stream(TS) domain. However, in view of the video editing, the splicing at an arbitrary picture unit can not be guaranteed. The splicing in the PES domain is only considered in this paper because the PES is one of the MPEG-2 system streams and this result could be directly extended to the video splicing techniques in the TS or PS domain. Thus. the problems that might occur when different two PES streams are spliced and its effects to the video quality are compared and analyzed. Based on this analysis. several methods that can resolve these problems directly in the PES domain are proposed. Consequently, the computer simulation demonstrates that the splicing at a GOP modulo is guaranteed to have good video quality even without considering the state of the PES packet only if the PES_packet_length field of the PES packet header is used.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.6
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• pp.296-301
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• 2006

Even though the emergency telecommunication make possible that specialist offers medical care over emergency cases in moving vehicle, we still have many problems in transmitting the image or video of patient over several wireless networks. To alleviate the effect of channel errors on compressed video bit-stream, this paper analyzed the error resilient features of JPEG2000 standard and measured the quality of transmission over noisy wireless channel, CDMA2000 1xEV-DO networks, compared to the features of error resilient tool of MPEG-4. We also proposed the optimum solution of transmitting images over real 3G network using JPEG2000 error resilient tool.

• Journal of Korea Multimedia Society
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• v.3 no.5
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• pp.479-494
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• 2000

Although the proliferation of real-time multimedia services over the Internet might indicate its successfulness in dealing with heterogeneous environments, it is obvious, on the other hand, that the internet now has to cope with a flood of multimedia data which consumes most of network communication channels due to a great deal of video or audio streams. Therefore, for the purpose of an efficient and appropriate utilization of network resources, it requires to develop and deploy a new scalable transmission technique n consideration of respective network environment and individual clients computing power. Also, we can eliminate the waste effects of storage device and data transmission overhead in that the same video stream duplicated according to QoS. The purpose of this paper is to develop a technology that can adjust the amount of data transmitted as an MPEG video stream according to its given communication bandwidth, and technique that can reflect dynamic bandwidth while playing a video stream. For this purpose, we introduce a media scalable media decomposer working on server side, and a scalable media composer working o n a client side, and then propose a scalable transmission method and a media sender and a media receiver in consideration of dynamic QoS. Those methods proposed her can facilitate an effective use of network resources, and provide multimedia MPEG video services in real-time with respect to individual client computing environment.

• Journal of Broadcast Engineering
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• v.5 no.2
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• pp.176-187
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• 2000

MPEG-4 is a digital bit stream format and associated protocols for representing multimedia content consisting of natural and synthetic audio, video and object data. This paper describes an application where multiple audio/visual data stream are combined in MPEG-4 and transported via MPTG-2 transport streams(TS). Also, this paper describes how to convert MPEG-4 Over MPEG-2 TS bit streams into MP4 file which Is designed to contain the media information of an MPEG-4 presentation in a flexible, extensible format. MPEG-4 is presented in the form of audio-visual objects that are arranged into an audio-visual scene by means of a scene descriptor and is composed of the audio-visual objects by means of an object descriptor. These descriptor streams are not defined MPEG-2 TS. So. this paper focuses on handling of these descriptors and parsing TS streams to get MPEG-4 data. The MPEG-4 Over MPEG-2 TS to MP4 format converter is implemented in the demonstrated systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.6
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• pp.1526-1537
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• 1998

The split-screen function on the multipoint control unit(MCU) which is usually using processing method based on pixel domain has many problems for manipulating the video signal in real-time. Although the researches and the developements to cope ith such problems are processing, these have too complex architecture to implement and are limited to method for H.261 video signal. In this paper, we propose a new mechanism for split-screen that can actually apply to ISO/IEC MPEG video standard. The new method that is proposed in this paper do the processes in complete compression domain, thus it is suitable for the application of real-time multipoint multimedia communication service. By simple interpreting and manipulating the MPEG video element stream, the split-screen functional module can be implemented easily and the result of the procedures does not accompany image degradation at all. Finally, the complexity of implementation, the aspect for processing delay and the loss of image quality as compared to that resulting in the case of applying the previous split-screen method has been investigated. And it is confirmed that the proposed mechanism has a significant advantage as a split-screen method.

• 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.

• Journal of Broadcast Engineering
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• v.21 no.3
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• pp.436-449
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• 2016

This paper compares the transport overhead of MMT (MPEG Media Transport) with that of MPEG-2 TS (Transport Stream). MPEG-2 TS is globally used in multiplexing compressed audio and video data in digital broadcast industry, including areas of DTV (Digital Television), IPTV (Internet Protocol Television), and DMB (Digital Multimedia Broadcasting). It was the early 1990s when MPEG-2 TS standard was established. After more than two decades of years since its first establishment, many parts of MPEG-2 TS turned out to be inappropriate to today's broadcast and communication environment. Given the situations, in 2014 MPEG (ISO/IEC JTC 1 SC 29/WG 11) standardized MMT as the next-generation multimedia transport standard hopefully that can replace MPEG-2 TS. In this paper, with assumptions of broadcast service scenarios we applied both MMT and MPEG-2 TS to each scenario and we calculated their transport overheads. We used a software program that counts the transport overhead, which was developed in our laboratory for this paper. And we conducted a comparative analysis based on the calculated result of transport overhead.

• Journal of Broadcast Engineering
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• v.8 no.3
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• pp.288-296
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• 2003

ATSC (Advanced Television System Committee) has specified 18 video formats for DTV (Digital Television), e.g., scan format, size format, and frame rate format conversion. Effective MPEG-2 video transcoders should support any conversion between the above-mentioned formats. Scan format conversion Is hard to Implement because it may often induce frame rate and size format conversion together. Especially. because of picture type conversion caused by scan format conversion, the computational burden of motion estimation (ME) in transcoding becomes serious. This paper proposes a fast ME algorithm for MPEG-2 video transcoding supporting scan format conversion. Firstly, we extract and compose a set of candidate motion vectors (MVs) from the input bit-stream to comply with the re-encoding format. Secondly, the best MV is chosen among several candidate MVs by using a weighted median selector. Simulation results show that the proposed ME algorithm provides outstanding PSNR performance close to full search ME, while reducing the transcoding complexity significantly.

• Annual Conference of KIPS
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• 2004.05a
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• pp.707-710
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• 2004

In the case of terrestrial DMB(Digital Multimedia Broadcasting) system that offers mobile multimedia broadcasting services, transmission error must be considered. Although DMB transmission system provides the error protection functions of convolution coding and Reed-Solomon (204,188,t=8) coding, additional error resilience video coding methods are needed to satisfy the requirement of BER lower than $10^{-8}$. In this thesis, we propose and evaluate effective error resilience coding schemes using the MPEG-4 redundant slice for MPEG-4 video services in the DMB environment. In this scheme, we analyze the drift error caused by transmission error based on the random noise concept and the redundant slice selection algorithm that selects the most influential slice in the view of the drift error increment.