• Title/Summary/Keyword: Video-conference

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A PRECISE AUDIO/VIDEO SYNCHRONIZATION SCHEME FOR MULTIMEDIA STREAMING

  • Chi, Won-Sup;Jung, Soon-Heung;Yoo, Jeong-Ju;Seo, Kwang-Deok
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2009.01a
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    • pp.49-54
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    • 2009
  • Synchronization between media is an important aspect in the design of multimedia streaming system. This paper proposes a precise media synchronization mechanism for digital video and audio transport over IP networks. To support synchronization between video and audio bitstreams transported over IP networks, RTP/RTCP protocol suite is usually employed. To provide a precise mechanism for media synchronization between video and audio, we suggest an efficient media synchronization algorithm based on NPT (Normal Play Time) which can be derivable from the timestamp information in the header part of RTP packet generated for the transport of video and audio streams. With the proposed method, we do not need to send and process any RTCP SR (sender report) packet which is required for conventional media synchronization scheme, and accordingly could reduce the number of required UDP ports and the amount of control traffic injected into the network.

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Playout Buffer based Rate Adaptation for Scalable Video Streaming over the Internet

  • Kang, Young-Wook;Jung, Young-H.;Choe, Yoon-Sik
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2009.01a
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    • pp.413-417
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    • 2009
  • The use of scalable video coding scheme has been regarded as a promising solution for guaranteeing the quality of service of the video streaming over the Internet because it is a capable coding scheme to perform quality adaptation depending on network conditions. In this paper, we use a streaming model that transmits base layer using TCP and enhancement layers using DCCP, which try to provide transmission reliability of the BL and TCP friendliness. Unlike pervious works, the proposed algorithm performs rate adaptation based on playout buffer status. The PoB status of the client is sent back periodically to the server and serves as a network congestion indicator. Experimental results show that our scheme improves streaming quality comparing with pervious scheme in the case of not only constant/dynamic background flows but also VBR-encoded video sequence.

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Integrated Multimedia Application Format for Active Video Browsing and Retrieval (효율적인 비디오 브라우징 및 검색을 위한 통합 멀티미디어 응용 형식)

  • Cho, Jun-Ho;Jin, Sung-Ho;Yang, Seung-Ji;Ro, Yong-Man
    • Proceedings of the Korea Information Processing Society Conference
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    • 2005.11a
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    • pp.155-158
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    • 2005
  • 본 논문에서는 MPEG 의 멀티미디어 응용 표준인 MAF(Multimedia Application Format)를 기반으로, 효율적인 비디오 콘텐츠의 검색 및 활용을 위한 통합 미디어 구조, 즉 비디오 MAF 를 제안한다. 제안하는 비디오 MAF 는 ISO 미디어 포맷을 기반으로 하고 단일의 비주얼 스트림과 다중 음성을 지원하기 위한 다수의 오디오 스트림, 내용기반의 정보를 포함하는 메타데이터, 그리고 비디오 콘텐츠의 대표 이미지를 동시에 포함하는 구조이다. 제안하는 파일포맷의 유용성을 검증하기 위해 비디오 MAF 로 생성 및 해석할 수 있는 부호기(encoder)와 복호기(decoder)를 설계하고 구현하여, 통합 미디어에 내재된 메타데이터를 이용한 효율적인 검색과 멀티트랙의 오디오 스트림을 활용한 다중 음성에 대한 지원이 가능함을 확인하였다. 또한 내재된 대표이미지는 비디오 콘텐츠에 대한 브라우징이 효과적으로 활용됨을 확인하였다.

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S/W-Based Video Codec Systems for Intranet and Internet Mulimedia Services

  • Kim, Yong-Han;Cho, Nam-Ik;Kim, Kichul
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 1997.06a
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    • pp.37-42
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    • 1997
  • This paper describes two different S/W-based video codec systems. One is a frame-based video codec with fixed structure based on ITU H.263 standard and the other an object-based video codec with flexible architecture based on ISO MPEG-4 standard currently under specification and planned to be finalized in 1998. These codes are an experimental implementations for examining the feasibility of real-time and/or flexible S/W-based video codecs operating in intra and/or internetworking environments.

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System Realization and Video Watermark with Spatial and interframe Information (공간 및 프레임간 정보를 이용한 비디오 워터마크와 시스템 구현에 관한 연구)

  • Kim, Ja-Hwan;Ryu, Kwang-Ryol
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2007.06a
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    • pp.157-160
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    • 2007
  • System realization and video watermarking using spatial and interframe information is presented in this paper. The system is constructed with DSP processor to process compression and watermark algorithm with real time. Video watermark algorithm is used the watermark insertion using the spatial and interframe. As a results, the processing time of D1 image per frame is 32.1msec in DSP.

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A Efficient Design of Naval Tactical Video Transmission (효과적인 해상 전술영상 전송에 관한 연구)

  • Hwang, Jaeryong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.10a
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    • pp.1125-1126
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    • 2015
  • A naval tactical video has utilized to implement network based remote C2 system, but it is difficult to transmit video intelligence data between tactical combat team and base-station due to the distance and sea condition. Threrfore, We first understand the naval tactical video transmission system and identify its limitations. Finally, we present an efficient method to increase transmission rate in the naval tactical video transmission system.

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A study of PES layer splicing for system layer editing on MPEG-2 based images(compare & analysis) (MPEG-2 기반영상의 시스템 영역에서의 편집을 위한 PES 영역에서의 스트림 splicing에 관한 연구(비교. 분석))

  • 김동준;최윤식
    • Proceedings of the IEEK Conference
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    • 2002.06d
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    • pp.77-80
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    • 2002
  • In this paper, We have studied for guaranteeing the clear display of MPEG-2 video sequence when conduct splicing of MPEG-2 system streams. we focus on the PES domain splicing considering video sequence. And we wish to make a base on the TS or PS domain splicing considering video sequence. For that, first, we compared and analyzed problems that is raised when different two PES streams are spliced and effects that affect the video sequence. And based on this analysis, we have searched for methods that resolve the cause of problems that can be happened in the display of video sequence directly in PES domain.

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Digital Video Camera Characterization Considering White Balance (White Balance를 고려한 디지털 비디오 카메라 Characterization)

  • 박종선;김대원;장수욱;김은수;송규익
    • Proceedings of the IEEK Conference
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    • 2002.06d
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    • pp.299-302
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    • 2002
  • Digital video camera can be a useful tool to capture images for use in colorimeter. However, the RGB signals generated by different digital video camera are not equal for the same scene. The digital video camera for use in colorimeter is characterized based on the CIE standard colorimetric observer. One method of deriving a colorimetric characterization matrix between camera RGB output signals and CIE XYZ tristimulus values is Polynomial modeling. In this paper, 3${\times}$3 linear matrix and 3${\times}$l1 polynomial matrix is used to investigate the characterization performance of the professional digital video camera. In experimental results, it is demonstrated that proposed 3${\times}$3 linear matrix has a reasonable degree of accuracy for use in colorimeter.

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Efficient Video Streaming Method over Wireless 3G Network (무선 3G 네트워크에서의 효율적인 비디오 전달 방법)

  • Dan, Byoung-Kyu;Lee, Sang-Ju;Nam, Hyeong-Min;Kim, Hye-Soo;Ko, Sung-Jea
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.51-52
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    • 2006
  • In this paper, we propose an efficient video streaming method to improve quality of service (QoS) over wireless 3G network. In the proposed method, the video stream is adopted in various available bandwidth (AB) using dynamic frame skipping (DFS). In addition, error concealment (EC)compensates the video degradation by transmitting the MVs of the skipped frame. Experimental results indicate that the proposed method provides better QoS for video stream than the conventional methods.

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2D Adjacency Matrix Generation using DCT for UWV contents

  • Li, Xiaorui;Lee, Euisang;Kang, Dongjin;Kim, Kyuheon
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2016.11a
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    • pp.39-42
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    • 2016
  • Since a display device such as TV or signage is getting larger, the types of media is getting changed into wider view one such as UHD, panoramic and jigsaw-like media. Especially, panoramic and jigsaw-like media is realized by stitching video clips, which are captured by different camera or devices. In order to stich those video clips, it is required to find out 2D Adjacency Matrix, which tells spatial relationships among those video clips. Discrete Cosine Transform (DCT), which is used as a compression transform method, can convert the each frame of video source from the spatial domain (2D) into frequency domain. Based on the aforementioned compressed features, 2D adjacency Matrix of images could be found that we can efficiently make the spatial map of the images by using DCT. This paper proposes a new method of generating 2D adjacency matrix by using DCT for producing a panoramic and jigsaw-like media through various individual video clips.

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