• Title/Summary/Keyword: GOP

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Minimum Variable Bandwidth Allocation over Group of Pictures for MPEG Video Transmission (MPEG 동영상 전송을 위한 GOP 단위의 최소 변경 대역폭 할당 기법)

  • Kwak, Joon-Won;Lee, Myoung-Jae;Song, Ha-Yoon;Park, Do-Soon
    • The KIPS Transactions:PartC
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    • v.9C no.5
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    • pp.679-686
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    • 2002
  • The transmission of prerecorded and compressed video data without degradation of picture quality requires video servers to cope with large fluctuations in bandwidth requirement. Bandwidth smoothing techniques can reduce the burst of a variable-bit rate stream by prefetching data at a series of fixed rates and simplifying the allocation of resources in the video servers and the network. In this paper, the proposed smoothing algorithm results in the optimal transmission plans for (1) the smallest bandwidth requirements, (2) the minimum number of changes in transmission rate, and (3) the minimum amount of the server process overhead. The advantages of the proposed smoothing algorithm have been verified through the comparison with the existing smoothing algorithms in diverse environments.

Improved Prediction Structure and Motion Estimation Method for Multi-view Video Coding (다시점 비디오 부호화를 위한 개선된 예측 구조와 움직임 추정 기법)

  • Yoon, Hyo Sun;Kim, Mi Young
    • Journal of KIISE
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    • v.41 no.11
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    • pp.900-910
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    • 2014
  • Multi-view video is obtained by capturing one three-dimensional scene with many cameras at different positions. The computational complexity of multi view video coding increases in proportion to the number of cameras. To reduce computational complexity and maintain the image quality, improved prediction structure and motion estimation method is proposed in this paper. The proposed prediction structure exploits an average distance between the current picture and its reference pictures. The proposed prediction structure divides every GOP into several groups to decide the maximum index of hierarchical B layer and the number of pictures of each B layer. And the proposed motion estimation method uses a hierarchical search strategy. This strategy method consists of modified diamond search pattern, progressive diamond search pattern and modified raster search pattern. Experiment results show that the complexity reduction of the proposed prediction structure and motion estimation method over JMVC (Joint Multiview Video Coding) reference model using hierarchical B pictures of Fraunhofer-HHI and TZ search method can be up to 40~70% while maintaining similar video quality and bit rates.

A Technique to Select Key-Frame for Identifying Harmful Video Images (동영상의 유해성 판별을 위한 대표 프레임 선정 기법)

  • Kim, Seong-Gyun;Park, Myeong-Chul;Ha, Seok-Wun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.10
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    • pp.1822-1828
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    • 2006
  • A key-frame should be efficiently selected to distinguish bad information from the videos. A previous technique selecting a key-frame mostly consists of the transformation scene-centered. In the case of harmful videos containing the quaility of continuous changes, the technique makes the total rate be reduced by an unnecessary key-frame. This thesis suggests the technique selecting a key-frame, an entry of the distinguishing system by using the quality of changes between the frames. In the experiment of this technique, it was proved that over 90% of the bad information was distinguished by the selected key frame, and also time efficiency was proved by showing 68% of decrement compared to the numbers I-frame. Therefore, This technique makes the system efficient to distinguish bad information, and efficiently can contribute to the distribution of the healthy movie information.

Fast Coding Mode Decision for Temporal Scalability in H.264/AVC Scalable Extension (시간적 계층에서의 스케일러블 부호화 고속 모드 결정 방법)

  • Jeon, Byeungwoo
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.6 no.2
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    • pp.71-75
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    • 2013
  • Recently proliferating heterogeneous multimedia service environments should be able to deal with many different transmission speeds, image sizes, or qualities of video. However, not many existing video compression standards satisfy those necessities. To satisfy the functional requirements, the standardization of the H.264/AVC Scalable Extension (SE) technique has been recently completed. It is an extension of the H.264/AVC which can encode several image sizes and qualities at the same time as a single bitstream. To perform optimum mode decision, motion estimation is performed for all MB modes, and the RD costs are compared to identify an MB mode with the smallest RD cost. This increases computational complexity of H.264/AVC SE encoding. In this paper, we propose an early skip mode detection scheme to reduce candidate modes and suggest an algorithm of fast mode decision utilizing reference modes according to the mode history.

A Study on assortment of Sim-Eui Form in Chosun Dynasty Period (조선시대 심의 유형에 관한 연구)

  • Chung Hye-Gyung;Kwon Young-Suk;Choi Eun-Joo;Moon Myeng-Ok
    • Journal of the Korean Society of Clothing and Textiles
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    • v.13 no.1 s.29
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    • pp.35-42
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    • 1989
  • The purpose of this study is to assort Sim-Eui form in Chosun Dynasty Period, so that we considered pictures of Sim-Eui in literature, portraits, and Sim-Eui. The results obtained are as follows; 1. Considering that United Sinla Period was related deeply to Tang Period, it is assumed that Sim-Eui was already transmitted in United Sinla Period. 2. Sim-Eui form was assorted roughly into two group, Straight line collar Sim-Eui (Gik-Ryeong Sim-Eui) and Sguare collar Sim-Eui (Bang-Ryeong Sim-Eui). The former was made to closs collars but not similar to carpenters sguare (Gop-Ja). The latter was made by Bek Gyum-Han at the begining, by the way it was not used widely. Then again Chun-Hu made the Sguare collar Sim-Eui in 19 c, it was used widely with Straight line collar Sim-Eui. 3. Sim-Eui in $\ulcorner$Ga-Rye-Bu-Chuei$\lrcorner$ was similar to those days Chullick, that verifies the Sim-Eui's influence on Chullick. 4. There was new simple Sim-Eui in $\ulcorner$Sa-Rye-Jip-Yo$\lrcorner$, it was similar to large sleeve's Durumagi, Heng-Eui. 5. Sim-Eui was sustituted by Gik-Ryeong Eui, Dap-Ho, Dan-Ryeong, Do-Po, Heng-Eui.

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Antioxidant Status and the Extent of Health Risks in Obese Korean Children

  • Lee WonMyo;Kim EulSang;Ha Aewha;Ximena Urrutia-Rojas
    • Nutritional Sciences
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    • v.8 no.2
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    • pp.133-139
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    • 2005
  • Objective: The purpose of this study was to determine serum antioxidant nutrients and the relationship between serum antioxidants and risks of chronic diseases in obese Korean children Methods: Normal weight Korean school children (0=170), mean age of 11.5$\pm$1.5, and obese (body fat mass > $28\%$) children (0=176), mean age of 11.0$\pm$1.8, were recruited Fat mass ($\%$) was determnined by Bioelectrical Impedance (BEI), and body mass index (BMI) was calculated Fasting blood was collected to measure serum antioxidant nutrients, vitamin A, vitamin E and zinc. Serum lipid profiles including total cholesterol (TC), high density cholesterol (HDL) and triglyceride (TG), and blood glucose, glutamic oxaloacetic transaminase (GOT), and glutamic pyruvic transaminase (GPI) were also determined. Differences in serum blood measurements between obese and normal children were assessed by independent t test. Pearson's correlation analysis was used to determine the relationship between variables. Results: Blood glucose, GPT, total cholesterol, and triglycerides concentrations were significantly higher among obese boys, compared to normal boys (p<005). Significantly lower concentrations of serum vitamin E, after adjustment for TG and TC, was shown in obese boys (0.26 mg/mg) and obese girls (0.31 mg/mg), compared to normal boys (0.36 mg/mg) and girls (0.38 mg/mg) (p<0.05). Fat mass ($\%$) was negatively con-elated with serum vitamin A and vitamin E. Conclusion: Obese Korean children showed insufficient serum vitamin E concentration and increased risk for diabetes, atherosclerosis, and liver disease. Since lower vitamin E concentration was negatively con-elated with atherogenic index, improved vitamin E status in children may decrease the risk of atherosclerosis later in life.

Semantics Aware Packet Scheduling for Optimal Quality Scalable Video Streaming (다계층 멀티미디어 스트리밍을 위한 의미기반 패킷 스케줄링)

  • Won, Yo-Jip;Jeon, Yeong-Gyun;Park, Dong-Ju;Jeong, Je-Chang
    • Journal of KIISE:Computer Systems and Theory
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    • v.33 no.10
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    • pp.722-733
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    • 2006
  • In scalable streaming application, there are two important knobs to tune to effectively exploit the underlying network resource and to maximize the user perceivable quality of service(QoS): layer selection and packet scheduling. In this work, we propose Semantics Aware Packet Scheduling (SAPS) algorithm to address these issues. Using packet dependency graph, SAPS algorithm selects a layer to maximize QoS. We aim at minimizing distortion in selecting layers. In inter-frame coded video streaming, minimizing packet loss does not imply maximizing QoS. In determining the packet transmission schedule, we exploit the fact that significance of each packet loss is different dependent upon its frame type and the position within group of picture(GOP). In SAPS algorithm, each packet is assigned a weight called QoS Impact Factor Transmission schedule is derived based upon weighted smoothing. In simulation experiment, we observed that QOS actually improves when packet loss becomes worse. The simulation results show that the SAPS not only maximizes user perceivable QoS but also minimizes resource requirements.

A Video Streaming Adaptive Packet Pre-marker in DiffServ Networks (DiffServ 네트워크에서 비디오 스트리밍을 위한 적응적 트래픽 마커 알고리듬 연구)

  • Jung, Young-H.;Kang, Young-Wook;Choe, Yoon-Sik
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.12B
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    • pp.735-742
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    • 2007
  • We propose an effective packet marking algorithm for video streaming in DiffServ network. Because legacy packet markers such as srTCM(single rate three color marker) cannot distinguish the importance of packet, these markers can cause quality degradation of streaming during the network congestion period. Recently proposed TMS (Two Marker System) [4] shows effectiveness in such scenario that video streaming service is struggling with other types of service traffic. However, if many video streaming services co-exist in DiffServ network and result in competition among themselves, then both legacy packet markers and even TMS cannot prevent drastic streaming quality degradation. To cope with this, we suggest A-TCPM (Adaptive time sliding window Three Color Marker) algorithm. In this algorithm, an A-TCPM module decides the color of a racket based upon the probability which is lead by current channel status and frame importance ratio. Simulation results show that proposed A-TCPM algorithm can enhance streaming service quality especially when overbooked video streaming sessions struggle with themselves.

A Study on Dynamic Bandwidth Allocation of Multiplexed MPEG Video Sources over ATM Network (ATM망에서 다중화된 MPEG 비디오소스의 동적 대역폭 할당)

  • 하창국;김장복
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.37 no.6
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    • pp.381-381
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    • 2000
  • In this paper, we propose a real-time bandwidth allocation scheme of multiplexed VBR MPEG video sequences over ATM network. In order to real time processing, multiplexed source is estimated by linear-prediction per measurement period. If the result CLR value were not sufficient, we proposed a overallocation method and a reallocation one to guarantee QoS. We used two kinds of sources, one is random multiplexed source made of foot different video sources, the other is the one considered the arrange of I frame in the sequence. With those sources, we analyzed the linear prediction, compared overallocation with reallocation method. As a result, in both schemes, the objected CLR value is achieved, the sufficient value COR under 10% when mp is over 1.8 sec, the utilization is over 0.9. Especially, the COR value of the reallocation scheme is better at the same condition.

A Study on Dynamic Bandwidth Allocation of Multiplexed MPEG Video Sources over ATM Network (ATM망에서 다중화된 MPEG 비디오소스의 동적 대역폭 할당)

  • Song, Jae-Yeon;Lee, Sang-Yeop;Ha, Chang-Guk;Kim, Jang-Bok
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.37 no.6
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    • pp.21-27
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    • 2000
  • In this paper, we propose a real-time bandwidth allocation scheme of multiplexed VBR MPEG video sequences over ATM network. In order to real time processing, multiplexed source is estimated by linear-prediction per measurement period. If the result CLR value were not sufficient, we proposed a overallocation method and a reallocation one to guarantee QoS. We used two kinds of sources, one is random multiplexed source made of foot different video sources, the other is the one considered the arrange of I frame in the sequence. With those sources, we analyzed the linear prediction, compared overallocation with reallocation method. As a result, in both schemes, the objected CLR value is achieved, the sufficient value COR under 10% when mp is over 1.8 sec, the utilization is over 0.9. Especially, the COR value of the reallocation scheme is better at the same condition.

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