• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.8
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• pp.1575-1580
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• 2012

In this paper, a DVB-T2(Digital Video Broadcasting-the 2nd Generation Terrestrial) receiver is designed under a USB-type windows environment, and the baseband frames for MPEG2-TS stream(File or Ethernet Modes) are analyzed for verifying the receiver. In addition, the performance of the BICM(Bit Interleaved Coding & Modulation) module in the receiver is analyzed in terms of PLP(Physical Layer Pipe) and L1(Layer 1) signals.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.9
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• pp.977-982
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• 2014

In this paper, we propose a system which can detect the flame in real time from the high-quality IP camera. First, open directly the RTSP streams transmitted from the IP camera using the library FFmpeg as opening a video file. The second thing is to extract the background images from video signal using Gaussian mixture model. Then the foreground images are obtained through subtracting operation between the input image and the background image. Separated foreground image through a mathematical morphology operation are considered as candidate area. By analysing colour information and dynamic characteristics of the candidate area, flame is determined finally. Through the experiments with input videos from IP camera, the proposed algorithms were useful to detect flames.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.376-380
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• 2009

Peer-to-Peer content delivery technology recently begins to be used not only for file sharing applications such as eDonkey but also for every kind of content services. KBS, a broadcasting company in Korea, is aggressively driving to apply Peer-to-Peer technology to KBS's commercial internet video service but we found that there are two big huddles. First, end users may refuse to share their own resources for KBS's cost reduction using Peer-to-Peer content delivery technology. Second, it may cause that the number of free-riders increases and the efficiency of the overall system would fall. From commercial service provider's perspective, we have to avoid that end users have unfavorable impressions on the service and the usefulness of Peer-to-Peer technology decreases. In order to overcome these problems, we studied how to offer incentive to end users and how much incentive would be reasonable, and then applied the result to real service for verification.

• The Journal of the Korea Contents Association
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• v.5 no.1
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• pp.217-227
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• 2005

In this paper, we present the result of an efficient implementation of DirectX-based multichannel visual monitoring system and the performance analysis of it. Our proposed system mainly consists of three subsystems: display, storage, and retrieval/playback. The display subsystem is designed to utilize efficiently H/W acceleration, overlay and flip of DirectX for faster real-time display, display synchronization among channels, and improvement of tearing artifact. For the performance improvement of storage speed, the storage subsystem is designed and implemented in DirectShow Filter-based multithreading architecture so that it can store multichannel video streams efficiently in each channel with minimizing data bottleneck among channels. In the retrieval and playback subsystem, efficient index file architecture and video data storage architecture, efficient playback architecture which can make playback be processed parallel among channels are designed and implemented for faster retrieval and playback,. Through experiments, our proposed system is shown to be maximally 2 times as fast in storaging speed and maximally 3.5 times as fast in retrieval and playback speed as the previous system.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.2
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• pp.29-38
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• 2010

Network Video Recorder becomes popular as a next generation surveillance system connecting all cameras and video server in network environment because it can provide ease of installation and efficient management and maintenance. But in case of data damage, the storage device in traditional NVR has no recovery scheme and it is disabled in processing real-time requests. In this paper, we propose an Reliable Storage using Parity and Mirroring scheme for improving reliability on storage device and maintaining system on realtime. RSPM uses a Liberation coding to recover damaged multimedia data and dynamic mirroring to repair corrupted system data and to maintain real-time operation. RSPM using the Liberation code is 11.29% lesser than traditional file system and 5.21% less than RSPM using parity code in terms of loss rate of damaged multimedia data.

• Journal of Korea Multimedia Society
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• v.13 no.1
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• pp.102-110
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• 2010

H.264 SVC(Scalable Video Coding) provides the advantages of low disk storage requirement and high scalability. However, a streaming server or a user terminal has to extract a bit stream from SVC file. This paper proposes a bit stream extraction method which can get the maximum PSNR value while date bit rate does not exceed the available network bandwidth. To do this, this paper obtains the information about extraction points which can get the maximum PSNR value offline and decides the spatial/temporal resolution of a bit stream at run-time. This resolution information along with available network bandwidth is used as the parameters to a bit stream extractor. Through experiment with JSVM reference software, we proved that proposed bit stream extraction method can get a higher PSNR value.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.4
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• pp.893-901
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• 2013

This paper suggests a method of developing live media streaming service through Linux server system on android system environment. The android application constructed in the experiment is able to record media while sending it to Linux server. Generated real time media data is send to linux server through Multipart Request class of Apache Tomcat server constructed on Linux system. Also in this research, by utilizing Android video player and media player class, development of android application structures was accomplished, which has methods of; playing live media stream data on video server, or playing live media stream data while saving stream data in cache. The structure and function of suggested system and application is confirmed by series of experiments.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.5
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• pp.925-938
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• 2010

Depending on network conditions, a communication network could be overloaded when media are transmitted. Research has been carried out to lessen network overloading, such as by filtering, load distribution, frame dropping, and other methods. Among these methods, one of the most effective is frame dropping, which reduces specified video frames for bandwidth diminution. In frame dropping, B-frames are dropped and then I- and P-frames are dropped, based on the dependency among the frames. This paper proposes a scheme for protecting copyrights by encryption, when frame dropping is applied to reduce the bandwidth of media based on the MPEG-4 file format. We designed two kinds of frame dropping: the first stores and then sends the dropped files and the other drops frames in real time when transmitting. We designed three kinds of encryption methods using the DES algorithm to encrypt MPEG-4 data: macro block encryption in I-VOP, macro block and motion vector encryption in P-VOP, and macro block and motion vector encryption in I-, P-VOP. Based on these three methods, we implemented a digital rights management solution for MPEG-4 data streaming. We compared the results of dropping, encryption, decryption, and the quality of the video sequences to select an optimal method, and found that there was no noticeable difference between the video sequences recovered after frame dropping and the ones recovered without frame dropping. The best performance in the encryption and decryption of frames was obtained when we applied the macro block and motion vector encryption in I-, P-VOP.

• Journal of Digital Contents Society
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• v.16 no.6
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• pp.917-925
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• 2015

WebRTC is one of the most recent technologies that supports browser-to-browser for voice calling, video chat, and P2P file sharing without the need of either internal or external plugins. However, there has some limitation which lets our development deal with many problems. This research will focus just on a small field of that problem which is bandwidth. While the bandwidth for downloading and uploading is fixed by service providers, but the number of users in a certain area is increasing largely by the time. In this paper, we propose a model to overcome the limitation of the bandwidth based on fuzzy control to adjust utilized bandwidth by changing frame rate and resolution of streaming video in the client itself.

• The KIPS Transactions:PartC
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• v.9C no.2
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• pp.297-306
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• 2002

Continuous multimedia applications require a guaranteed retricval and transfer rate of streaming data, which conventional file server mechanism generally does not provide. In this paper we describe a dynamic negotiated admission control and dick bandwidth scheduling framework for Continuous Media (CM : e.g., video) servers. The framework consists of two parts. One is a reserve-based admission control mechanism and the other part is a scheduler for continuous media streams with dynamic resource allocation to achieve higher utilization than non-dynamic scheduler by effectively sharing available resources among contending streams to improve overall QoS. Using our policy, we could increase the number of simultaneously running: clients that coo]d be supported and cot]d ensure a good response ratio and better resource utilization under heavy traffic requirements.