• Journal of Aerospace System Engineering
• /
• v.13 no.2
• /
• pp.10-18
• /
• 2019

In this paper, we present the results of a developed LTE/Wi-Fi-based video transmission system which can be applied in small unmanned aerial vehicles of 25kg or less. The developed video transmission system comprised of airborne datalink terminal, ground datalink terminal, and used LTE and Wi-Fi wireless data communication technologies to transmit videos of resolution higher than HD (720p/30fps, 1080p/30fps) taken by small UAV. The airborne device is designed to efficiently transmit real-time streaming video through the incorporation of H.264 video processing board. Ground tests and evaluation indicated the possibility of the developed system to transmit real-time videos from close distance in regards to non-line-of-sight area.

• Journal of KIISE:Computer Systems and Theory
• /
• v.35 no.4
• /
• pp.150-157
• /
• 2008

This paper presents a design and implementation of realtime video player that operates on a tiled-display system consisting of multiple PCs to provide a very large and high resolution display. In the proposed system, the master process transmits a compressed video stream to multiple PCs using UDP multicast. All slaves(PC) receive the same video stream, decompress, clip their designated areas from the decompressed video frame, and display it to their displays while being synchronized with each other. A simple synchronization mechanism based on the H/W clock of each slave is proposed to avoid the skew between the tiles of the display, and a flow-control mechanism based on the bit-rate of the video stream and a pre-buffering scheme are proposed to prevent the jitter The proposed system is implemented with Microsoft DirectX filter technology in order to decouple the video/audio codec from the player.

• Journal of Digital Convergence
• /
• v.13 no.11
• /
• pp.141-148
• /
• 2015

In this paper, for developing and implementing the HLS(Http Live Streaming) transmitter based embedded linux which is operated easily and cheap and lower power, portable in all networks and client environments compared to exist video live streaming transmitters. We design the developed HLS transmitter hardware using the Arm11 core and then porting the Embedded Linux OS(Operating System) and implementing the HLS protocol using the open source FFmpeg and Segmenter. For proving the performance of developed HLS transmitter, we make the testing environment for testing the performance of HLS transmitter including the notebook, iPhone, android Phone, Notebook and then analysis the received video in the client displayer. In this paper, we suggest the developed HLS transmitter performance data values higher than the Apple company's HLS recommended specification values and the picture of developed HLS transmitter operation in the testing environment. The application field of this paper result is that the man who works in the emergency situation take HLS and transmit the live emergency situation to the head quarter using this portable HLS.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2005.11a
• /
• pp.225-228
• /
• 2005

본 논문에서 제안한 실시간 모바일 감시 시스템은 소형 화상 카메라를 이용하여 PC상에서 구현할 수 있도록 함으로써 저렴한 비용으로 시스템 구축이 이루어 졌고, 동작 검출을 위한 영상처리에서 프레임 메모리를 사용하지 않고, 기준 영상과 현재 영상의 블록별 특징 값만을 비교하기 때문에 처리 속도가 현저하게 향상되었다. 검출된 영상을 모바일 클라이언트로 전송하기 위해서 WAP 풀 기반 영상전송 방법을 사용하여 WIPI SDK로 구현함으로써 감시 영상의 변환과 전송을 실시간으로 구현할 수 있었다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2007.06a
• /
• pp.175-178
• /
• 2007

According to recently presented QoS architecture by 3GPP, a traffic conditioner may be deployed to provide conformance of the negotiated QoS. A real-time frame-layer rate control method which can be applied to the traffic conditioner is proposed. The proposed rate control method uses a non-iterative optimization method for low computational complexity, and performs bit allocation at the frame level to minimize the average distortion over an entire sequence as well as variations in distortion between frames. The proposed algorithm does not produce time delay from encoding, and is suitable for real-time low-complexity video encoder.

• Journal of Advanced Navigation Technology
• /
• v.5 no.2
• /
• pp.149-157
• /
• 2001

A high speed data link capability is one of the critical factors in determining the performance of the spaceborne SAR system with high resolution. It is due to the strict requirement for the real-time data transmission from a series of massive raw image data of spaceborne SAR to the ground station in a limited time of mission. In this paper, based on the data link model characterized by the spaceborne small SAR system, the high rate multi-channel data link module is designed including link storage, link processor, transmitter, and wide-angle antenna. The design results are presented with the performance analysis on the data link budget as well as the multi-mode data rate in association with the SAR imaging mode of operation from high resolution to the wide swath.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.1C
• /
• pp.92-101
• /
• 2004

This paper proposes a algorithm to extract the variety region (object) from video for the real-time encoding of MPEG-4 based. The previous object segmentation methods cannot used the videophone or videoconference required by real-time processing. It is difficult to transfer a video to real-time because it increased complexity for the operation of each pixel on the spatial segmentation and temporal segmentation method proposed by MPEG-4 Working Group. But algorithm proposed for this thesis not operates a pixel unit but operates a macro block unit. Thus this enables real-time transfer. But this algorithm cannot extract several object for a image using proposed algorithm as previous algorithm. On system constructed by encoder and decoder. A proposed algorithm inserted for encoder as pre-process.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2007.11a
• /
• pp.1025-1026
• /
• 2007

인공위성을 이용한 실시간 차량정보 전송장치는 정지궤도 위성을 이용하여 차량 정보 및 위치정보를 위성 영상 데이터를 이용하여 실 시간 전송 및 분석하는 시스템이다. 저궤도 관측 위성을 통하여 기 확보된 영상데이터 및 그 동안의 위성 기술 개발 과정에서 습득된 HW/SW 기술 및 GPS 처리 기술을 이용하여 개발 되었으며 향후 물류 및 관련 등 산업 전반에 많은 파급효과가 있을 것으로 기대된다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.11 no.8
• /
• pp.1582-1588
• /
• 2007

According to recently presented QoS architecture by 3GPP, a traffic conditioner may be deployed to provide conformance of the negotiated QoS. In this paper, a real-time frame-layer rate control method which can be applied to the traffic conditioner of 3GPP is proposed. The proposed rate control method uses an efficient frame skipping algorithm method for low computational complexity, and performs bit allocation at the frame level to minimize the average distortion over an entire sequence as well as variations in distortion between frames. The proposed algorithm does not produce time delay from encoding, and is suitable for real-time low-complexity video encoder.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2003.05b
• /
• pp.1477-1480
• /
• 2003

본 논문에서는 실시간 데이터 및 보안데이터, 영상데이터 통을 전송할 때 잡음으로 인해 발생되는 데이터 오류를 효과적으로 복원하기 위해 오류 정정 능력이 뛰어난 터보코드를 적응하여 신뢰성 있는 영상전송 시스템을 실현하였다. 영상처리 시스템에서는 CCTV, 비디오 카메라 등에서 나오는 NTSC(National Television System Committee) 영상 신호를 비디오 디코더를 통해 A/D 변환하여 출력하였다. 변환된 디지털 영상정보는 두 개의 영상필드로 출력되며 그중 하나의 필드가 선택되는 알고리즘을 EPLD(Erasable Programmable Logic Device) 로직회로로 구성하여 디지털 영상 데이터를 절반으로 줄이는 시스템을 구현하였다. 터보코드의 부호기, 복호기 시스템에서는 실수연산이 가능한 DSP(Digital Signal Processor)를 사용하여 터보코드를 구현하였으며, 터보코드의 성능을 좌우하는 인터리버부분은 블록 인터리버를 적용하여 설계하였다.