Multipoint videoconferencing with scalable video coding

来源 :Journal of Zhejiang University Science A(Science in Engineer | 被引量 : 0次 | 上传用户:weiweixiao09
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
We describe a system for multipoint videoconferencing that offers extremely low end-to-end delay, low cost and complexity, and high scalability, alongside standard features associated with high-end solutions such as rate matching and per- sonal video layout. The system accommodates heterogeneous receivers and networks based on the Internet Protocol and relies on scalable video coding to provide a coded representation of a source video signal at multiple temporal and spatial resolutions as well as quality levels. These are represented by distinct bitstream components which are created at each end-user encoder. Depending on the specific conferencing environment, some or all of these components are transmitted to a Scalable Video Conferencing Server (SVCS). The SVCS redirects these components to one or more recipients depending on, e.g., the available network con- ditions and user preferences. The scalable aspect of the video coding technique allows the system to adapt to different network conditions, and also accommodates different end-user requirements (e.g., a user may elect to view another user at a high or low spatial resolution). Performance results concerning flexibility, video quality and delay of the system are presented using the Joint Scalable Video Model (JSVM) of the forthcoming SVC (H.264 Annex G) standard, demonstrating that scalable coding outper- forms existing state-of-the-art systems and offers the right platform for building next-generation multipoint videoconferencing systems. We describe a system for multipoint videoconferencing that offers extremely low end-to-end delay, low cost and complexity, and high scalability, alongside standard features associated with high-end solutions such as rate matching and per-sonal video layout. The system accommodates heterogeneous receivers and networks based on the Internet Protocol and relies on scalable video coding to provide a coded representation of a source video signal at multiple temporal and spatial resolutions as well as quality levels. These are represented by distinct bitstream components which are created at each end -user encoder. Depending on the specific conferencing environment, some or all of these components are transmitted to a Scalable Video Conferencing Server (SVCS). The SVCS redirects these components to one or more recipients depending on, eg, the available network con- ditions and user preferences. The scalable aspect of the video coding technique allows the system to adapt to different networ k conditions, and also accommodates different end-user requirements (eg, a user may elect to view another user at a high or low spatial resolution). Performance results concerning flexibility, video quality and delay of the system are presented using the Joint Scalable Video Model (JSVM) of the forthcoming SVC (H.264 Annex G) standard, demonstrating that scalable coding outperforms forms of state-of-the-art systems and offers the right platform for building next-generation multipoint videoconferencing systems.
其他文献
目的:了解唇鳞状细胞癌患者人乳头瘤病毒感染的情况.方法:对收集到的9例临床诊断唇癌病例的石蜡组织标本应用Luminex及PCR的方法对HPV感染进行基因检测,应用免疫组织化学的方
会议
目的:探讨鼠类肉瘤滤过性毒菌(V-raf)致癌同源体B1(BRAF)基因突变、钠碘同向转运体(NIS)蛋白在山东沿海地区甲状腺乳头状癌(PTC)患者癌组织和癌旁组织中的表达及意义.方法:收
会议
目的:评价NP方案诱导化疗+同步适形调强放疗治疗局部晚期鼻咽癌的毒副作用和疗效.方法:2005年1月-2009年1月62例经病理学或细胞学证实的局部晚期鼻咽癌,采用NP方案诱导化疗,N
会议
“自由”、“权利”在中国社会已经成为口头禅,成为一个人为自己的某些言行辩护的本能反应—尤其是这些言行,在道德上极有争议的时候。  比如,前段时间,上海地铁针对性骚扰增多的情况,发了一条微博提醒女士们穿着不要太暴露,以免引来“狼”的骚扰,结果惹了麻烦,引发了两位“女权行为艺术家”的抗议和很多人“怎么穿衣是人的自由、权利”的指责。  这种争议后,展现的是中国民众有了新的“权利意识”,不再总眼巴巴等着“
藜蒿(Artemisiaselengensis),又名蒌蒿、水艾、柳蒿(东北),是菊科蒿属唯一的多年生水生草本植物。地下茎粗壮色白,地上茎直立,高50-150cm,直径约4-8mm,无毛,紫红色。单叶互生抱茎,基叶羽状
会议
目的:探讨BRAF<suP>V600E</suP>突变及RET表达并存与甲状腺乳头状癌(Papillary thyroidcancer,PTC)侵袭性的关系.方法:收集50例PTC患者术后病理组织切片均由2位高年资病理医师复
会议
目的:探讨鼻咽癌患者血浆EBV-DNA含量在临床诊断中的意义.方法:收集2007年12月~2011年12月在南方医院耳鼻咽喉头颈外科住院的初诊鼻咽癌患者310例,检测治疗前血清EBV VCA/IgA
会议
研究了红掌 (A .andreanum)Kaumana品种的花 (佛焰苞、佛焰花序和花柄 )的生长和发育。在从叶腋出现之前8d ,花长约 0 .3cm ,由 2片卷缩的托叶围住位于苞叶叶柄基部。在叶柄快速伸长期 ,花 (0 .8~
目的:甲状腺球蛋白(Tg)在分化型甲状腺癌(DTC)术后及131I治疗后可以作为一个重要的肿瘤标记物,但在清除甲状腺组织(清甲)治疗前,其临床意义仍有争议.本研究旨在探讨术后或停
会议