• 방송공학회논문지
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• 제20권6호
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• pp.921-927
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• 2015

본 논문에서는 효율적인 스케일러블 다시점 비디오 부호화를 수행하기 위해 필요한 참조화면 재순서화, 마킹 프로세스, 참조픽처 리스트 구성을 포함하는 DPB (Decoded Picture Buffer) 작동을 위한 새로운 설계 방법을 제안한다. 다양한 실험 결과를 통해서 제안된 방법에 의해 스케일러블 다시점 비디오 부호화에 있어서 개선된 압축효율을 얻을 수 있고 BD-Rate 및 BD-PSNR 측면에서 향상된 비디오 화질을 얻을 수 있음을 확인한다.

• Journal of information and communication convergence engineering
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• 제14권4호
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• pp.240-245
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• 2016

Scalable video streaming over wireless networks has many challenges. The most significant challenge is related to packet loss. To overcome this problem, in this paper, we propose an unequal loss protection (ULP) method using a new forward error correction (FEC) mechanism for robust scalable video streaming over wireless networks. For an efficient FEC assignment considering video quality, we first introduce a simple and efficient performance metric, the layer-based recovery rate (LRR), for quantifying the unequal error propagation effects of the temporal and quality layers on the basis of packet losses. LRR is based on the unequal importance in both the temporal and the quality layers of a hierarchical scalable video coding structure. Then, the proposed ULP-LRR method assigns an appropriate number of FEC packets on the basis of the LRR to protect the video layers against packet lossy network environments. Compared with conventional ULP algorithms, the proposed ULP-LRR algorithm demonstrates a higher performance for various error-prone wireless channel statuses.

• 방송공학회논문지
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• 제13권1호
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• pp.119-127
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• 2008

Transmission of video over Internet or wireless network requires coded stream capable of adapting to dynamic network conditions instantly. To meet this requirement, various scalable video coding schemes have been developed, among which the Scalable Video Coding (SVC) extension of the H.264/AVC is the most recent one. In comparison with the scalable profiles of previous video coding standards, the SVC achieves significant improvement on coding efficiency performance. For adapting to dynamic network bandwidth, the SVC employs inter-layer switching between different temporal, spatial or/and fidelity layers, which is currently supported with instantaneous decoding refresh (IDR) access unit. However, for real-time adaptability, the SVC has to frequently employ the IDR picture, which dramatically decreases the coding efficiency. Therefore, an extension of SP picture from the AVC to the SVC for an efficient inter-layer switching is investigated and presented in this paper. Simulations regarding the adaptability to dynamic network bandwidth are implemented. Results of experiment show that the SP picture added SVC provides an average 1.2 dB PSNR enhancement over the current SVC while providing similar adaptive functionality.

• ETRI Journal
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• 제35권6호
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• pp.990-1000
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• 2013

This paper describes the scalable extension of High Efficiency Video Coding (HEVC) to provide flexible high-quality digital video content services. The proposed scalable codec is designed on multi-loop decoding architecture to support inter-layer sample prediction and inter-layer motion parameter prediction. Inter-layer sample prediction is enabled by inserting the reconstructed picture of the reference layer (RL) into the decoded picture buffer of the enhancement layer (EL). To reduce the motion parameter redundancies between layers, the motion parameter of the RL is used as one of the candidates in merge mode and motion vector prediction in the EL. The proposed scalable extension can support scalabilities with minimum changes to the HEVC and provide average Bj${\o}$ntegaard delta bitrate gains of about 24% for spatial scalability and of about 21% for SNR scalability compared to simulcast coding with HEVC.

• 대한임베디드공학회논문지
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• 제3권4호
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• pp.175-181
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• 2008

This paper describes the SVC-based media adaptation system which can adapt video contents optimally to various consumption environments in an IP-based transmission scenario. As key technologies, we will present scalable video coding, SVC-based adaptive media transmission, and SVC-based adaptation signaling technology.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.352-354
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• 2005

As further Studies on 4th generation mobile telecommunication are progressed, the importance of a Cross-Layer is being increased. However, it has focused on coordination model only between MAC layer and PHY layer. It is necessary to expand into II' layer and upper layers. In this paper, we introduce a Cross-layer optimization which can be used to transmit video data with effect by managing resources among layers. It can gives further more adaptive method to solve QoS model problem than single layer.

• 방송공학회논문지
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• 제20권4호
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• pp.497-508
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• 2015

최근 HD(High Definition)화질 및 UHD(Ultra High Definition)화질과 같은 고품질 방송 서비스가 등장하고, 무선 네트워크 기술의 발달로 스마트폰, 태블릿 PC 등과 같은 휴대용 멀티미디어 기기들이 보편화됨에 따라, 비디오 콘텐츠의 전달 및 소비 환경이 다양화되고 있다. 따라서 스케일러빌러티(Scalability)의 현실적 필요성이 점점 절실해 졌으며, 시간, 공간, 화질 등의 확장성을 제공하는 Scalable Video Coding(SVC)이 등장하였다. 최근 ISO/IEC의 MPEG(Moving Picture Experts Group)와 ITU-T의 VCEG(Video Coding Experts Group)이 공동으로 결성한 Joint Collaborative Team on Video Coding(JCT-VC)에 의해 Scalable High Efficiency Video Coding(SHVC) 표준이 제정되었다. 본 논문은 공간적, 시간적, 화질적 스케일러빌러티를 제공하기 위하여 SHVC의 표준에 포함된 툴 뿐만 아니라 SHVC 표준화 과정에서 논의되었던 다양한 스케일러블 부호화 툴들을 소개하고, 기존 단일 계층 부호화 방식으로 부호화한 결과와 비교하여 SHVC의 부호화 효율에 대한 성능을 분석하였다. 이러한 성능 분석은 향후 부호화 성능 향상을 위한 알고리즘 개발 및 고속 부호화기 개발을 위한 부호화 툴의 선별 및 조정에 유용할 것으로 판단된다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.50-53
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• 2002

There are increasing needs to deliver the multimedia streaming over heterogeneous networks. When considering network environments and equipment accessed by user, delivery of video streaming must be scalable. There are many kinds of scalable video coding: spatial, temporal, SNR, and hybrid. The SNR scalable and spatial resolution, but different SNR quality with respect to layers. The 1-layer SNR scalable encoder produces SNR scalable video streams with ease. But, there is drift problem. Modified 1-layer approach does not have this problem but coding inefficiency, and is not MPEG-compliant. The present MPEG-compliant 2-layer encoder comes out to reduce coding rate. But it still use only base layer to encode whole layer. In this paper, we propose adaptive MPEG-compliant 2-layer encoder. Using linear combination algorithm, encoder use 1 motion vector to encode the sequences efficiently. By dong this, we can achieve the coding efficiency of SNR scalable coding.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.192-194
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• 2005

Acceptance of the international standards for video compression, such as H.261, MPEG-1 and MPEG-2, along with the developments in video codec hardware, has created an explosion of application. Among these, the long time quest for long-distance digital video transmission causes an increasing interest in transporting compressed video over networks which are nontraditional for this purpose, including asynchronous transfer mode networks, the Internet, and cellular and wireless channels. Transmission of compression video over packet network is improved for error resilience. And layered video coding techniques improves error resilience. We present a efficient method of scalable video coding for low bandwidth.

• 대한임베디드공학회논문지
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• 제4권1호
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• pp.35-41
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• 2009

The H.264/SVC enables network-adaptive video transmission to smart device which uses wireless network. But, quality scalability of H.264/SVC does not consider personal subjective image quality. In addition, its network efficiency also does not optimized because it uses MGS(Medium Grained Scalability) and CGS(Coarse Grained Scalability). Thus, this paper proposed a new scalable ROI algorithm for not only subjective image quality improvement but also network adaptation. To experiment our proposed a scheme, we added designed algorithm to JSVM(Joint Scalable Video Model) open source video codec of H.264/SVC. Experiment was performed according to the pre-defined scenario for simulating various network conditions. Finally, experimental result showed our proposed scalable ROI scheme. It is better than traditional non-selective scheme in subjective video quality.