The scalable extension of H.264/AVC, known as scalable video coding or SVC, is currently the main focus of the Joint Video Team’s work. In its present working draft, the higher level syntax of SVC follows the design ...The scalable extension of H.264/AVC, known as scalable video coding or SVC, is currently the main focus of the Joint Video Team’s work. In its present working draft, the higher level syntax of SVC follows the design principles of H.264/AVC. Self-contained network abstraction layer units (NAL units) form natural entities for packetization. The SVC specification is by no means finalized yet, but nevertheless the work towards an optimized RTP payload format has already started. RFC 3984, the RTP payload specification for H.264/AVC has been taken as a starting point, but it became quickly clear that the scalable features of SVC require adaptation in at least the areas of capability/operation point signaling and documentation of the extended NAL unit header. This paper first gives an overview of the history of scalable video coding, and then reviews the video coding layer (VCL) and NAL of the latest SVC draft specification. Finally, it discusses different aspects of the draft SVC RTP payload format, in- cluding the design criteria, use cases, signaling and payload structure.展开更多
Mobile Ad-hoc Networks (MANETs) operate without infrastructure where nodes can move randomly. Therefore, routing in MANETs is a challenging task. In this paper we evaluate the performance of three important MANET rout...Mobile Ad-hoc Networks (MANETs) operate without infrastructure where nodes can move randomly. Therefore, routing in MANETs is a challenging task. In this paper we evaluate the performance of three important MANET routing protocols: Ad hoc On-Demand Distance Vector (AODV), Dynamic Source Routing (DSR) and Optimized Link State Routing (OLSR) when employed to forward scalable video contents. AODV and DSR are reactive protocols in that routing paths are established once needed. On the other hand, OLSR is a proactive routing protocol where routing information is exchanged and maintained continuously. The goal of the performance evaluation in this study is to assess the performance of AODV, DSR and OLSR in communicating scalable video contents. In the simulation part of this paper, a real video sequence is communicated where the characteristics and quality of the video decoded at receiver nodes are evaluated. NS2 along with extensions and other evaluation frameworks have been used to assess the performance of the MANET routing protocols when used for scalable video communication. The framework allows starting from a raw video that is encoded, packetized, transmitted through a network topology and collected at receiver to be decoded, played, and evaluated. Delay and timing constraints are taken into consideration when decoding the received video packets.展开更多
在可分级视频编码(SVC,scalable video coding)的框架下,利用分布式视频编码(DVC,distributed video coding)技术,设计了一种低编码复杂度的SVC方案。该系统具有空间可分级的特性,各分层中仅用到了传统的帧内编码技术和DVC技术,最大限...在可分级视频编码(SVC,scalable video coding)的框架下,利用分布式视频编码(DVC,distributed video coding)技术,设计了一种低编码复杂度的SVC方案。该系统具有空间可分级的特性,各分层中仅用到了传统的帧内编码技术和DVC技术,最大限度的减小了SVC系统的编码复杂度。在该系统中,充分利用分级系统的特点,在增强层(EL)的解码中提出了一种基于二次搜索和残差补偿(DSRCB)的边信息(SI)生成算法和一种基于时空域虚拟噪声模型的估计算法,并针对各分层图像的频域特性优化了量化模型。实验表明,与基于传统视频编码技术的SVC系统相比,该系统具有极低的复杂度,性能超过了非可分级的DVC系统,而且在较小的GOP(group of pictures)尺寸下获得了接近传统SVC系统的性能。展开更多
D2D用户缓存技术可以有效减轻基站(Base Station,BS)的缓存负担。为了满足用户对多种视频文件质量的需求,可以采用可伸缩视频编码(Scalable Video Coding,SVC)方法来处理文件。文中提出了一种端到端(Device-to-Device,D2D)用户缓存场景...D2D用户缓存技术可以有效减轻基站(Base Station,BS)的缓存负担。为了满足用户对多种视频文件质量的需求,可以采用可伸缩视频编码(Scalable Video Coding,SVC)方法来处理文件。文中提出了一种端到端(Device-to-Device,D2D)用户缓存场景下对SVC文件的定价和缓存策略联合优化算法。首先考虑用户和内容提供者(Content Provider,CP)的利益,结合SVC文件各层数据包间的联系,推导了缓存文件的激活概率以及请求文件通过D2D传输或BS传输的概率;在此基础上,综合考虑传输与缓存消耗,定义用户和CP的效用函数,建立以CP为领导者,用户为跟随者的斯坦伯格博弈模型;最后,分别优化文件价格与缓存策略。仿真结果表明,该算法能够合理利用网络中的传输和缓存资源,从而提高系统的总效用。展开更多
Scalable video coding (SVC) is the most promising video format for applications of collaborative communication. MPEG-21 standard has newly emerged to enable the interoperability of multimedia delivery in heterogeneous...Scalable video coding (SVC) is the most promising video format for applications of collaborative communication. MPEG-21 standard has newly emerged to enable the interoperability of multimedia delivery in heterogeneous environments. In this paper we study adaptation of SVC bitstream in the context of MPEG-21 multimedia framework. For interfacing SVC bit- stream with MPEG-21 based adaptation system, we propose three SVC specific adaptation operators. Based on our previous work with multidimensional video adaptation, we present an effective approach, using MPEG-21 DIA AdaptationQoS description tool, to model QoS control for SVC adaptation. Then we show how the operator values could be computed from that representation. For the actual adaptation at bitstream level, we propose a procedure to remove the unnecessary NAL units from an SVC bitstream. The result of this study enables QoS management of SVC streaming in an efficient and standardized manner.展开更多
文摘The scalable extension of H.264/AVC, known as scalable video coding or SVC, is currently the main focus of the Joint Video Team’s work. In its present working draft, the higher level syntax of SVC follows the design principles of H.264/AVC. Self-contained network abstraction layer units (NAL units) form natural entities for packetization. The SVC specification is by no means finalized yet, but nevertheless the work towards an optimized RTP payload format has already started. RFC 3984, the RTP payload specification for H.264/AVC has been taken as a starting point, but it became quickly clear that the scalable features of SVC require adaptation in at least the areas of capability/operation point signaling and documentation of the extended NAL unit header. This paper first gives an overview of the history of scalable video coding, and then reviews the video coding layer (VCL) and NAL of the latest SVC draft specification. Finally, it discusses different aspects of the draft SVC RTP payload format, in- cluding the design criteria, use cases, signaling and payload structure.
文摘Mobile Ad-hoc Networks (MANETs) operate without infrastructure where nodes can move randomly. Therefore, routing in MANETs is a challenging task. In this paper we evaluate the performance of three important MANET routing protocols: Ad hoc On-Demand Distance Vector (AODV), Dynamic Source Routing (DSR) and Optimized Link State Routing (OLSR) when employed to forward scalable video contents. AODV and DSR are reactive protocols in that routing paths are established once needed. On the other hand, OLSR is a proactive routing protocol where routing information is exchanged and maintained continuously. The goal of the performance evaluation in this study is to assess the performance of AODV, DSR and OLSR in communicating scalable video contents. In the simulation part of this paper, a real video sequence is communicated where the characteristics and quality of the video decoded at receiver nodes are evaluated. NS2 along with extensions and other evaluation frameworks have been used to assess the performance of the MANET routing protocols when used for scalable video communication. The framework allows starting from a raw video that is encoded, packetized, transmitted through a network topology and collected at receiver to be decoded, played, and evaluated. Delay and timing constraints are taken into consideration when decoding the received video packets.
文摘在可分级视频编码(SVC,scalable video coding)的框架下,利用分布式视频编码(DVC,distributed video coding)技术,设计了一种低编码复杂度的SVC方案。该系统具有空间可分级的特性,各分层中仅用到了传统的帧内编码技术和DVC技术,最大限度的减小了SVC系统的编码复杂度。在该系统中,充分利用分级系统的特点,在增强层(EL)的解码中提出了一种基于二次搜索和残差补偿(DSRCB)的边信息(SI)生成算法和一种基于时空域虚拟噪声模型的估计算法,并针对各分层图像的频域特性优化了量化模型。实验表明,与基于传统视频编码技术的SVC系统相比,该系统具有极低的复杂度,性能超过了非可分级的DVC系统,而且在较小的GOP(group of pictures)尺寸下获得了接近传统SVC系统的性能。
文摘D2D用户缓存技术可以有效减轻基站(Base Station,BS)的缓存负担。为了满足用户对多种视频文件质量的需求,可以采用可伸缩视频编码(Scalable Video Coding,SVC)方法来处理文件。文中提出了一种端到端(Device-to-Device,D2D)用户缓存场景下对SVC文件的定价和缓存策略联合优化算法。首先考虑用户和内容提供者(Content Provider,CP)的利益,结合SVC文件各层数据包间的联系,推导了缓存文件的激活概率以及请求文件通过D2D传输或BS传输的概率;在此基础上,综合考虑传输与缓存消耗,定义用户和CP的效用函数,建立以CP为领导者,用户为跟随者的斯坦伯格博弈模型;最后,分别优化文件价格与缓存策略。仿真结果表明,该算法能够合理利用网络中的传输和缓存资源,从而提高系统的总效用。
文摘Scalable video coding (SVC) is the most promising video format for applications of collaborative communication. MPEG-21 standard has newly emerged to enable the interoperability of multimedia delivery in heterogeneous environments. In this paper we study adaptation of SVC bitstream in the context of MPEG-21 multimedia framework. For interfacing SVC bit- stream with MPEG-21 based adaptation system, we propose three SVC specific adaptation operators. Based on our previous work with multidimensional video adaptation, we present an effective approach, using MPEG-21 DIA AdaptationQoS description tool, to model QoS control for SVC adaptation. Then we show how the operator values could be computed from that representation. For the actual adaptation at bitstream level, we propose a procedure to remove the unnecessary NAL units from an SVC bitstream. The result of this study enables QoS management of SVC streaming in an efficient and standardized manner.
