An end-to-end robust approach for scalable video over the internet

With the growth of the Internet and abundant network resources, video streaming is becoming one of the increasingly important Internet applications. However, the current IP-based network provides only a single class best effort service. Video packet can be regarded as a packet loss by the video decoder either due to network congestion or due to exceeding the maximum delay threshold. It remains an open challenging task as to how to cope with the packet loss in the video streaming over the Int…     

Unequal error protection under bitrate constraint for video streaming over internet

This article describes a simple packet-level FEC system suitable for unequal error protection of layered video streams, that we called TAPIOCA (in French, Transport Audiovisuel avec Protection Inégale des Objets et Contrôle d’Admission). It is designed in a way that the FEC overhead induced by redundant packets is perfectly controlled by the sender. In order to achieve that, TAPIOCA calculates on-the-fly the optimal erasure code to be used, video data unit by video data unit, under a given bitrate constraint. In addition, and contrary to the well-known PET (Priority Encoding Transmission) system, the video data units of each layer are encoded separately. This is especially useful when all layers are not output from the video coder at the same time. Simulation results for MPEG-4 video streaming show that the proposed FEC system can be very efficient even if packet losses are due to network congestion. Moreover, comparison with PET system shows that TAPIOCA exhibits better performance, considering criteria including the decodable frame rate, protection system efficiency and computational cost.     

Network-status aware quality adaptation algorithm for improving real-time video streaming over the internet

Multimedia Tools and Applications - Video streaming over Internet has been gaining momentum and several quality adaptation schemes have been reported to improve quality of the streamed videos. Most...     

User interface design for older adults

The percentage of older adults is expected to increase to unprecedented levels within the next decade. Little attention has been devoted to understanding, organizing, and accommodating the needs of older adults with respect to interaction with computers. Indeed, most usability studies have focused on the needs of younger adults, to the neglect of the elderly. As computerized products increasingly appeal to broader audiences, the needs of older adults will become a concern for designers. This review focuses on the organization and presentation of characteristics of older adult learners, along with recommendations based on those characteristics, with the hope that their accessibility will enhance designer intuition and provide suitable information to guide user testing.     

Adaptive interface selection over cloud-based split-layer video streaming via multi-wireless networks

As mobile devices such as tablet PCs and smartphones proliferate, the online video consumption over a wireless network has been accelerated. From this phenomenon, there are several challenges to provide the video streaming service more efficiently and stably in the heterogeneous mobile environment. In order to guarantee the QoS of real-time HD video services, the steady and reliable wireless mesh is necessary. Furthermore, the video service providers have to maintain the QoS by provisioning streaming servers to respond the clients’ request of different video resolution. In this paper, we propose a reliable cloud-based video delivery scheme with the split-layer SVC encoding and real-time adaptive multi-interface selection over LTE and WiFi links. A split-layer video streaming can effectively scale to manage the required channels on each layer of various client connections. Moreover, split-layer SVC model brings streaming service providers a remarkable opportunity to stream video over multiple interfaces (e.g. WiFi, LTE, etc.) with a separate controlling based on their network status. Through the adaptive interface selection, the proposed system aims to ensure the maximizing video quality which the bandwidth of LTE/WiFi accommodates. In addition, the system offers cost-effective streaming to mobile clients by saving the LTE data consumption. In our system, an adaptive interface selection is developed with two different algorithms, such as INSTANT and EWMA methods. We implemented a prototype of mobile client based on iOS particularly by using iPhone5S. Moreover, we also employ the split-layer SVC encodes in streaming server-side as the add-on module to SVC reference encoding tool in a virtualized environment of KVM hypervisor. We evaluated the proposed system in an emulated and a real-world heterogeneous wireless network environments. The results show that the proposed system not only achieves to guarantee the highest quality of video frames via WiFi and LTE simultaneous connection, but also efficiently saves LTE bandwidth consumption for cost-effectiveness to client-side. Our proposed method provides the highest video quality without deadline misses, while it consumes 50.6% LTE bandwidth of ‘LTE-only’ method and 72.8% of the conventional (non-split) SVC streaming over a real-world mobile environment.     

User interface design for military AR applications

Designing a user interface for military situation awareness presents challenges for managing information in a useful and usable manner. We present an integrated set of functions for the presentation of and interaction with information for a mobile augmented reality application for military applications. Our research has concentrated on four areas. We filter information based on relevance to the user (in turn based on location), evaluate methods for presenting information that represents entities occluded from the user??s view, enable interaction through a top-down map view metaphor akin to current techniques used in the military, and facilitate collaboration with other mobile users and/or a command center. In addition, we refined the user interface architecture to conform to requirements from subject matter experts. We discuss the lessons learned in our work and directions for future research.     

足球视频搜索引擎中的用户偏好挖掘

目的：互联网信息量的急速增长使得人们需要花费大量时间从搜索引擎召回的结果中浏览自身感兴趣的内容,结合用户的搜索日志信息和社交平台信息,提出一种分层的实时偏好挖掘模型,为用户提供个性化搜索服务。方法：在系统分析偏好挖掘的国内外研究现状的基础上,针对足球视频,提出一种分层权重无向图（Hierarchical Weighted Undirected Graph,HWUG）用户偏好模型,充分考虑了用户偏好之间的关联信息,通过获取用户足球领域的显式和隐式反馈信息,提取反馈信息中的偏好标签和偏好动作,并引入时间衰减因子,实现了用户足球偏好的实时计算。结果：算法已经应用在在搜球网（www.findball.net）的个性化检索结果排序和视频推荐上,并已经取得了很好的效果。结论：实验结果表明,结合特定领域的知识,基于分层无向权重图模型的偏好挖掘算法能更准确和实时反映用户的足球偏好。     

Private-to-private communications over the internet

The meet-in-the-middle network provides a simple way to restore end-to-end connectivity between distant hosts located behind network address translators, and does so without reconfiguring the NAT devices that lie on the path between the hosts. The article proposes an internetworking method as part of a broader research project involving remote access to various IP-ready sensors, computers, cameras, and microphones installed in the home environment to monitor the health and safety of bedridden quadriplegic patients. This system configures all its IP devices with private IP addresses.     

User interface and interactivity display for converging PC,IPTV, and mobile device in a video sharing service

This paper proposes a user interface and interactivity adaptor for PCs, Internet protocol televisions (IPTVs), and mobile devices. The adaptor accounts for the screen limitations for display of mobile devices and the remote control limitations for the interactivity of IPTVs. A framework for convergence of these client‐side devices is also proposed as a basis for a video sharing service. In‐depth verification and evaluation demonstrate the robustness of the proposed adaptor.     

基于用户界面模型的界面模板

界面模板是一种崭新的界面设计模式，提出了基于界面模型的界面模板概念，在支持界面自动生成的界面开发方法中实现从抽象界面到具体界面的转化。讨论了界面模板的构成与表达、界面模板的分类以及界面模板库体系结构，说明了界面模板的用法。     

User interface design assistance for large-scale software development

The User Interface Design Assistant (UIDA) addresses the specific design problems of style and integration consistency throughout the user interface development process and aids in the automated feedback and evaluation of a system's graphical user interface according to knowledge-based rules and project-specific design examples. The UIDA system is able to quickly identify inconsistent style guide interpretations and UI design decisions resulting from distributed development of multiple UI sub-systems. This case arises when each sub-system conforms to the general style guide rules, but when integrated together, may appear inconsistent.This work was conducted jointly at the University of Southern California's Center for Software Engineering, and the Arcadia Project, University of California Irvine.     

User interface modeling in UMLi

Although user interfaces represent an essential part of software systems, the Unified Modeling Language )UML) seems to have been developed with little specific attention given to user interface issues. Several researchers have investigated integrating interface modeling techniques with UML. In UML, one models tasks using extended activity diagrams rather than by incorporating a completely new notation into UML. UMLi also addresses the relationships between use cases, tasks, and views, and thoroughly addresses the relationship between tasks and the data on which they act. UMLi is probably the most technically mature proposal for interface development in UML.     

User perception of adapting video quality

In general, video quality adaptation and video quality evaluation are distinct activities. Most adaptive delivery mechanisms for streaming multimedia content do not explicitly consider user-perceived quality when making adaptation decisions. Equally, video quality evaluation techniques are not designed to evaluate instantaneous quality where the quality is changing over time. We propose that an Optimal Adaptation Trajectory (OAT) through the set of possible encoding exists, and that it indicates how to adapt encoding quality in response to changes in network conditions in order to maximize user-perceived quality. The subjective and objective tests carried out to find such trajectories for a number of different MPEG-4 video clips are described. Experimental subjective testing results are presented that demonstrate the dynamic nature of user perception with adapting multimedia. The results demonstrate that adaptation using the OAT out-performs conventional adaptation strategies in which only a single aspect of the video quality is adapted. In contrast, the OAT provides a mechanism to adapt multiple aspects of the video quality thereby giving better user-perceived quality in both the short and long term.     

Robust wireless sharing of internet video streams

The gateways are the performance bottleneck of wireless mesh access networks and thus alleviating stress on them is essential to making such wireless networks robust and scalable. Using proxy servers or wireless peer-to-peer streaming techniques can help reduce the gateway load. However, these techniques, because they are data caching methods, do not save wireless resources. We instead consider a communication-sharing approach in this paper. Traditional stream sharing solutions depend on cooperation with the video server. However, in the wireless access network it is difficult to cooperate with online video sites. To address this problem in wireless mesh access networks, we propose a distributed video sharing technique called Dynamic Stream Merging (DSM). DSM is able to improve the robustness of the access network without cooperation from the online video site or the users and has the intelligence to handle sudden spikes in demand for certain videos due to specific events, thereby preventing adverse effects to other daily wireless traffic. The technique can also leverage the 80:20 data access pattern, common for many video applications, to substantially increase the service throughput. We explain the DSM technique, present the system prototype, and discuss the experimental results.     

User interface analysis for groupware applications in the TOUCHE process model

Groupware applications require a special attention during the first development stages since, in addition to interactions of the users with the system, interactions among the users through the system should be considered. The methodological approach we present in this paper is part of a complete process model called TOUCHE. The proposal is based on several models to perform the analysis of CSCW systems. The methodology presented to address the analysis stage provides the mechanisms to specify the organization of the participants of a system, the roles they play, the interaction of the users within the system and the interaction among the different participants through the system, i.e., person–computer–person interaction. The integration within the process model is also slightly depicted. The artefacts of the whole process are robustly connected, what facilitates the inter and the intra-stage traceability. Finally, a case study is presented to demonstrate the applicability of the proposal.     

User interface for a better eye contact in videoconferencing

When people talk to each other, eye contact is very important for a trustful and efficient communication. Video-conferencing systems were invented to enable such communication over large distances, recently using mostly Internet and personal computers. Despite low cost of such solutions, a broader acceptance and use of these communication means has not happened yet. One of the most important reasons for this situation is that it is almost impossible to establish eye contact between distant parties on the most common hardware configurations of such videoconferencing systems, where the camera for face capture is usually mounted above the computer monitor, where the face of the correspondent is observed. Different hardware and software solutions to this problem of missing eye contact have been proposed over the years. In this article we propose a simple solution that can improve the subjective feeling of eye contact, which is based on how people perceive 3D scenes displayed on slanted surfaces, and offer some experiments in support of the hypothesis.