• 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.

• Journal of Multimedia Information System
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• 제2권1호
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• pp.153-162
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• 2015

In today's pervasive computing environments, multimedia content should be adapted to meet various conditions of network connections, terminals, and user characteristics. Scalable Video Coding (SVC) is a key solution for video communication over heterogeneous networks, where user terminals have different capabilities. This paper presents a standard-compliant approach that adapts an SVC bitstream to support multiple users. The adaptation problem is formulated as an optimization problem, focusing on the tradeoff between qualities of different spatial layers of an SVC video. Then the adaptation process is represented by standard metadata of MPEG-21, which can be solved by universal processing to enable interoperable and automatic operation. Our approach provides the users with optimal quality, a wide flexibility, and seamless adaptation. To the best of our knowledge, this is the first study that shows the adaptation tradeoff between spatial layers of a conforming SVC bitstream.

• Journal of information and communication convergence engineering
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• 제8권1호
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• pp.71-76
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• 2010

Scalable video coding (SVC) has been standardized as an extension of the H.264/AVC standard. SVC allows straightforward adaptation of video streams by providing layered bit streams. In this paper, we propose a SVC video-based multicasting system preserving scalable security which is able to provide a SVC video service while maintaining information security. In order to maintain information security between a server and a client during all transmission time, the proposed system immediately performs a packet filtering process without decoding with respect to encrypted data received in a routing device, thereby reducing an amount of calculations and latency.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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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.

• 한국통신학회논문지
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• 제34권5B호
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• pp.517-525
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• 2009

인터넷을 통하여 다른 서비스에 비해 상대적으로 많은 대역폭을 필요로 하는 비디오 스트리밍 서비스를 제공할 경우, 다른 플로우들과의 형평성을 제공하면서 비디오 서비스의 품질을 보장해야한다. 이를 위하여 본 논문에서는 스케일러블 비디오 압축 스트림에 대한 멀티채널 TCP-friendly 스트리밍 기법을 제안하였다. 제안 구조는 스케일러블 비디오 코딩으로 압축된 비디오 정보를 기본계층(baseline layer)은 TCP를 이용하여 손실 없이 전송하고 상위계층(enhancement layer)는 TFRC (TCP friendly rate control)을 이용하여 전송하도록 하였다. 이때, TFRC로 전송되는 상위계층 레이어에 대한 전송률은 수신측 재생버퍼의 상태와 전송 미디어의 계층별 부호화율을 고려하여 적응적으로 결정되도록 제안하였다. 시뮬레이션 결과를 통하여, 이러한 적응적 전송률 제어를 통하여 제안 스트리밍 방식이 기존 방식에 비해 네트워크 상황변화에 신속히 적응하고 혼잡상황에서도 일정수준의 서비스 품질을 보장함을 확인 할 수 있다.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제16권10호
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• pp.975-979
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• 2010

기존의 스트리밍 품질 적용 기법들은 네트워크의 혼잡상황에서 네트워크의 안정성을 향상시키는데 반해 스트리밍 서비스의 빈번한 재생품질 변화로 인해 사용자에게 제공되는 스트리밍 서비스의 체감품질을 보장하지 못한다. 본 논문에서는 SVC(스케일러블 비디오 코딩) 비디오 스트리밍 서비스의 체감품질을 보장하기 위해, 네트워크 상태 변화를 고려한 스트리밍 품질 적응 기법을 제안한다. 제안하는 기법은 미디어 특성을 고려한 가용대역폭 측정 기법을 이용하여 네트워크의 가용대역폭을 측정하고, 측정된 가용대역폭을 기반으로 전송되는 SVC 비디오 스트림의 품질 변화를 부드럽게 조절한다. 실험을 통해 제안하는 기법이 재생품질의 변화를 최소화하여 스트리밍 서비스의 체감품질을 보장할 수 있음을 확인하였다.

• 방송공학회논문지
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• 제16권3호
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• pp.520-529
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• 2011

본 논문에서는 SVC(Scalable Video Coding) 및 MVC(Multiview Video Coding) 등의 다계층(miulti-layer) 비디오의 효율적인 적응 HTTP 스트리밍을 위한 MPEG-2 TS(Transport Stream) 헤더의 확장을 제안한다. 먼저 TS로 다중화한 SVC/MVC를 HTTP를 통하여 스트리밍할 경우 계층별 적응 스트리밍을 지원하기 위한 기존 TS의 한계점을 분석하고, TS 헤더의 확장을 통하여 TS 레벨에서 효율적인 적응을 제공하는 시그널링(signaling) 기법을 제시한다. 본 논문의 헤더 확장은 TS의 적응 헤더(adaptation header)의 사적 데이터 필드(private data field)를 이용하여 스케일러빌리티 및 뷰 정보를 기술함으로써 TS와의 호환성을 유지하면서 TS 레벨에서의 다양한 스케일러블 계층 단위로 적응(adaptation)을 가능하게 한다. 제안한 기법과 기존의 PID(packet ID)를 사용한 방법에 대하여 적응의 유연성 및 복잡도 등을 비교 분석한다. 또한 제안한 기법의 TS 오버헤드 증가를 분석하고 이를 최소화하기 위한 헤더 확장 기법을 제안한다.

• 한국멀티미디어학회논문지
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• 제9권12호
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• pp.1560-1571
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• 2006

In order to transmit multimedia streams over the network with a timely changing channel bandwidth such as Internet, scalable video coding schemes have been studied to represent video in flexible bitstream. Much research has been made on how to represent encoded media(such as video) bitstream in scalable ways. In this paper, rte propose an optimal selection of the objects for MPEG-4 bitstream adaptation to meet a given constraint. We adopt a multiple choice knapsack problem with multi-step selection for the MPEG-4 objects with different bit-rate scaling levels in the MPEG-4 bitstream. The bitstream adaptation based on the optimal selection result is then to fetch the necessary parts of the MPEG-4 bitstream to constitute an adapted version of the original MPEG-4 binary resource. The experiment results show that the optimal selection of MPEG-4 objects for a given constraint can promisingly be made which meets the given constraint.

• 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.

• 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.