High-quality Video Streaming Research Articles

Evaluation of traffic dispersion methods for synchronous distributed multimedia data transmission on multiple links for group of mobile hosts

In this paper, we propose a multimedia data transmission method, Multitrack, that achieves high-speed and efficient data transmission between multiple mobile hosts and the internet. Users of the hosts in a cluster can see a high quality streaming video by sharing the received multimedia data cooperatively with the other hosts. In Multitrack, it is important to disperse traffic according to the quality of multiple links in order to offer a stable multimedia data transmission. We also propose an effective traffic dispersion method for this environment, and evaluate this method and other basic methods by simulations.

Multidimensional transcoding for adaptive video streaming

The prominence of digital video on the Internet is rising constantly. Faster Internet connections and more powerful devices make video streaming over the Internet more and more popular. With mobile devices, however, the usability of digital videos that are streamed over a wireless network connection is still limited by the available resources. Mobile devices are often not capable of receiving and decoding high quality video streams from the Internet because of their limited resources as well as due to the limitations of a wireless network connection. The presentation, for instance, of a video stream with 1920x1080 pixels on a screen with a resolution of only 320x240 pixels is not possible without a high amount of processing power at the receiving device. The transmission of such a high quality video stream over a wireless link may additionally consume a large part of the available network capacity, which then may interfere active network connections of other devices. A limited network capacity may additionally prevent the device from decoding and displaying the video stream at all. One solution of these problems is to perform an adaptation of the video stream to the requirements of mobile devices during the transmission of the stream to the client.

Traffic cops and bottlenecks [Internet bandwidth

When we log on to the Internet, we assume we'll be able to use any service on any website, whether it is reading a Web page or watching a high-quality video stream, whenever we want, at the fastest speeds that our connections allow. With government services moving online, there's also a growing expectation that citizens will use high-quality broadband access to interact with the state. But networks and Internet service providers (ISPs) are feeling the strain of rising bandwidth demands.

Quality-Aware Cooperative Proxy Caching for Video Streaming Services

By applying a proxy mechanism widely used in WWW systems to video streaming systems, low-delay and high-quality video distribution can be accomplished without imposing extra load on the system. The video streaming system proposed in this paper consists of a video server and multiple proxy servers. In our mechanism, proxies communicate with each other and retrieve missing video data from an appropriate server by taking into account transfer delay and offerable quality. In addition, the quality of cached video data is adapted appropriately at a proxy to cope with the client-to-client heterogeneity in terms of the available bandwidth, end-system performance, and user preferences on the perceived video quality. Through simulation experiments, it is shown that our proposed mechanism can provide users with low-delay and highquality video streaming services. Furthermore, to verify our mechanism, we implement a real system for MPEG-4 video streaming services and show that our proxy caching system can provide users with a continuous video distribution under dynamically changing network conditions.

A FC/AL-Based P2P Network for Personal Archive and Sharing

Peer-to-Peer (P2P) networking technology can share a variety of contents, including the broadcast TV/Film programs. With the popularity of personal video recorders, people stores their favorite TV/film titles in the hard drive. It is clear that these recorders can easily archive and share TV/film contents over P2P networks once they are equipped with broadband connections. This is important because this emerging P2P network can provide an alternative content archive and distribution channel to the conventional unidirectional broadcasting. In other words, people can have another way to obtain TV contents that they were not able to record at the time of broadcast or purchase via the conventional DVD sale. As part of on-going research, we demonstrate that Fibre Channel -Arbitration Loop (FC-AL) technology can serve well as the storage network for personal archive and real-time content distribution. In our proposed architecture for TV content archive and sharing, the FC-AL directly connects many digital video recorders, a pool of network disks, and a content managing server.Via our integrated storage/network architecture, users can share their archives either from their own digital video recorders or the pool of networked disks. The results are the significant time-shifting for the users to watch the programs. The proposed network architecture also relieves the storage limitation of the digital video recorders, and users can help each other by archiving the “hard-to-find’ contents. In this paper, we present the technical schemes to fully utilize the performance of this emerging network. These schemes include (1) Buffering schemes to guarantee the concurrent video streams; (2) Matching schemes for communication pairs; (3) Load-balancing schemes; and (4) multiple-loop staging schemes to extend the time-shift. With the effective buffering schemes, we have demonstrated over 300 high-quality video streams can be supported by the system with less than 1display jitters.To maximally utilize the FC-AL bandwidth and full-duplex property in both directions, we have developed effective schemes to match the communication pairs between users and the pool of network disks. It is also a common situation that most playback requests are concentrated on a few popular programs. From the perspective of overall system performance, such a skewed access pattern may cause serious load-unbalancing problems because some overloaded PVRs can become performance bottlenecks even though there are still many disks having sufficient available band-width. To solve this problem, we switch playback requests as well as replicate popular program (as minimally as possible). Finally, efficient staging methods have been proposed between the networked disks in different FC-AL loops to successfully extend the time-shift from 3-day to 70 days.

Integrating high quality video streams with FTP traffic over a noisy high capacity wireless cellular channel

In this paper we propose and evaluate a Medium Access Control (MAC) protocol for the efficient integration of high quality video traffic with ftp data packet traffic over a wireless cellular channel of very high capacity. We envision a system where the mobile terminals are considered to be high performance devices with extended storage capabilities which can act like cache memories streaming multimedia material. Via an extensive simulation study we evaluate the system's performance under a variety of possible loads which consist of actual MPEG-4 streams and ftp sessions, and we show that our scheme outperforms another, well-known MAC protocol for cellular networks.

Minimum cost scheduling of stored video in dynamic bandwidth allocation networks

In this paper, a minimum cost scheduling algorithm is proposed for high-quality video streaming in dynamic bandwidth allocation networks. It targets the problem of service cost minimization in optimal smoothing algorithms. Based on the bandwidth usage and the number of bandwidth renegotiations, service cost functions are defined for each transmission segment and a group of segments. The relative cost flags are also defined for each segment, which indicate the direction in which the segment is merged with less service cost. By inspecting the relative cost flags on the boundaries of segments, it is determined whether neighboring segments should be merged, until there is no reduction in the overall service cost. From the simulation results, the proposed algorithm is shown to merge neighboring segments in the direction minimizing the service cost. Compared with the optimal smoothing algorithm, the overall service cost is greatly reduced with a similar level of network resource usage and less transmission rate variability, especially for larger renegotiation cost parameters.

A Priority Selected Cache Algorithm for Video Relay in Streaming Applications

With the popularization of Internet, many users can obtain various multimedia services through heterogeneous Internet. Among these services, video streaming application is the most challenging. Because of time constraint and variable bit rate (VBR) property of a video, the problem of streaming high quality video is insufficient external WAN bandwidth. Therefore, it is difficult to expand high quality video streaming services. To solve this problem, we proposed a novel video cache algorithm, called the Optimal Cache (OC) algorithm, for a relay video proxy. By caching portions of a video in a relay video proxy closed to clients, the video playback quality can be guaranteed and the problem of insufficient WAN bandwidth across Internet is eliminated. However, data packets are often lost while streaming video data across Internet, which downgrades video playback quality and even halts the video playback. In this paper, we refine the OC algorithm and propose a novel Priority Selected Cache (PSC) algorithm to select maximum high priority video data for caching in a relay video proxy. The PSC algorithm reduces the decoding errors caused by packet loss, improves error recovery, and provides QoS-guaranteed video playback. On the basis of experiment results with testing several benchmark videos, we show that the PSC algorithm caches at least 15% more high priority video data in a relay video proxy than conventional OC algorithm. Additionally, the PSC algorithm uses minimum storage in a relay video proxy and reduces the maximum bandwidth requirement in the WAN (as does the OC algorithm) subject to QoS-guaranteed video playback

Practical algorithms for scheduling video data in a local area network environment

Simultaneous transmission of multiple high quality video streams from a server to the clients is becoming an increasingly important class of traffic in a network of workstations or cluster environment. With a powerful symmetric multiprocessor (SMP) as the server and a high-speed network, such transmission is practicable from a hardware point of view. However, the actual construction of such a video data server system entails tackling a number of difficult problems related to the provision of strict quality of service (QoS) guarantees. Among others, the smoothing and scheduling of multiple video packet streams are two crucial issues. Smoothing is concerned with reducing the rate variability of video streams in view of the fact that video data are usually compressed in a variable bit rate fashion. Scheduling is important to guarantee the requested QoS levels while maximizing the utilization of the resources. Although much work on smoothing has been done, it is not clear which scheduling scheme is suitable for multiplexing smoothed video data to the network. In this paper we present an extensive performance study of the EDF and RM scheduling algorithms which are modified to provide QoS guarantees for smoothed video data. With a probabilistic definition of QoS, admission control conditions are incorporated into the two algorithms. Furthermore, a counter-based scheduling module is included as the core scheduling mechanism which adaptively adjusts the actual QoS levels assigned to requests. Our theoretical analysis of the two modified algorithms, called QEDF and QRM, shows that the QRM algorithm is more robust than the QEDF algorithm for different workload and utilization conditions. We also propose to use a new metric called meta-QoS to quantify the overall performance of a packet scheduler given a set of simultaneous requests. In our experiments based on an SMP-based Linux platform, we find that the QRM algorithm can sustain a rather stable level of meta-QoS even when the workload and utilization levels are increased. On the other hand, the QEDF algorithm, due to its conservative admission control policy, is found to be not suitable for a high level of utilization and a large number of requests. In view of the lower complexity of the QRM algorithm, it seems that the QRM approach is a more suitable candidate for packet scheduling in the client-server environment considered in our study.

Application-Coexistent Wire-Rate Network Monitor for 10 Gigabit-per-Second Network

To apply network monitoring functions to emerging high-quality video streaming services, we proposed an application-coexistent monitor (APCM). In APCM, a streaming server can works as an active monitor and a passive monitor. In addition, IP packets sent from the server carry monitoring information together with application's data such as video signals. To achieve APCM on a 10-Gbps network, we developed a network interface card for an application-coexistent wire-rate network monitor (AWING NIC). It provides (1) a function to append GPS-based accurate timestamps to every packet that streaming applications send and receive, which can be used for real-time monitoring of delays and inter-packet gap, and (2) functions to capture and generate 10-Gbps wire-rate traffic without depending on packets' size, achieved by our highly-efficient DMA-transfer mechanisms. Such monitoring capability are unprecedented in existing PC-based systems because of the limitation in PC system's architecture. As an evaluation of APCM in an actual network, we conducted an experiment to transmit a 6-Gbps high-quality video stream over an IP network with the system in which we installed the AWING NIC. The results revealed that the video stream became highly bursty by passing through the network, and the observed smallest inter-packet gap corresponds to the value of 10-Gbps wire-rate traffic, which supports the effectiveness of our development.

Hierarchical resource allocation for robust in-home video streaming

High quality video streaming puts high demands on network and processor resources. The bandwidth of the communication medium and the timely arrival of the frames necessitate a tight resource allocation. Given the dynamic environment where videos are started and stopped and electro-magnetic perturbations affect the bandwidth of the wireless medium, a framework is needed that reacts timely to the changes in network load and network operational conditions. This paper describes a hierarchical framework, which can handle the dynamic network resource allocation in a timely manner.

High resolution live streaming with the HYDRA architecture

Digital continuous media (CM) are now well established as an integral part of many applications. With highdefinition (HD) displays becoming increasingly common and large network bandwidth available, high-quality video streaming has become feasible, and novel, innovative applications possible. However, the majority of existing systems for HD-quality streaming are based on offline content and use elaborate buffering techniques that introduce long latencies. Therefore, these solutions are ill-equipped for interactive real-time applications. Also, due to the massive amount of data required to transmit such streams, simultaneously achieving low latency and keeping the bandwidth low are contradictory requirements. Our HYDRA project (Highperformance Data Recording Architecture) focuses on the acquisition, transmission, storage, and rendering of high-resolution media such as H-quality video and multiple channels of audio. HYDRA consists of multiple components to achieve its overall functionality. Here we elaborate on the live-streaming capabilities of HYDRA that enable media streaming across an IP-based network with commodity equipment.

Large-scale personalized video streaming with program insertion proxies

Increasingly intelligent Internet overlay networks promise to deliver streaming media and value-added media services in ways that cannot be achieved easily with conventional broadcast networks. Such an overlay would allow an individual viewer or groups of viewers to receive unique programming content (e.g., commercial advertisements, entertainment) that matches their previously specified preferences. Toward this end, we introduce a scalable overlay network architecture and signaling mechanism that permits dynamic program insertions in live high-quality video streams transmitted over IP networks. We describe the implementation of an application proxy that dynamically inserts prerecorded video programs into NTSC Dl quality motion-JPEG streams with no visible artifacts. We argue that on-demand program switching is merely a first step toward a new generation of media services; increases in computing power ultimately permits network-based proxies to manipulate and augment multimedia content as it flows through the network.

Congestion based resource sharing in multi-service networks

The internet traffic is increasingly composed of streams of packets with very diverse quality of service (QoS) requirements: from those containing standard, best-effort traffic, such as e-mail or http sessions, to internet telephony and high-quality video streaming demanding dedicated allocation of network capacity. However, while methods based on externality pricing exist to offer socially optimal prices to the groups of users demanding different grades of the best-effort service class, less attention has been devoted to the implementation of such pricing models to the improvement of network resources allocation in a multi-service setting (i.e., a network offering various grades of both guaranteed and best-effort level of service). This paper addresses the problem through an end-to-end approach that combines a congestion-based pricing model for resource sharing with a QoS network model, based on admission rules. We describe a measurement-based approach for QoS path pricing that results in improved resource allocation policies between QoS and best-effort traffic. We also present the results of a large-scale simulation study that shows how this pricing scheme increases both end user value and system throughput with low computational overhead.

Video Streaming in Nursing Education

Distance education is a standard form of instruction for many colleges of nursing. Web-based course and program content has been delivered primarily through text-based presentations such as PowerPoint slides and Web search activities. However, the rapid pace of technological innovation is making available more sophisticated forms of delivery such as video streaming. High-quality video streams, created at the instructor's desktop or in basic recording studios, can be produced that build on PowerPoint or create new media for use on the Web. The technology required to design, produce, and upload short video-streamed course content objects to the Internet is described. The preparation of materials, suggested production guidelines, and examples of information presented via desktop video methods are presented.

High-quality video streaming system for plasma diagnostics using super SINET

Smooth cooperative research requires effective remote participation. Toward this end, the National Institute for Fusion Science (NIFS) has enhanced its network among domestic institutes. The new network, called the Super Science information network (SINET), connects national universities and governmental organizations and has a 10 G bps backbone. NIFS connected Kyoto University and Nagoya University to this network at a speed of 1 G bps each way in 2002, and plans to connect other universities. In addition, a real-time video streaming system is being developed for remote participation in this network. Due to bandwidth limitations of the network, lossy motion image formats, such as Real Video or MPEG, are widely used for video streaming service. For example, the minimum transfer ratio to send a VGA-sized video image at the rate of 30 fps is 27 MB/s, or 220 M bps, which exceeds ordinal network capacities. However, lossy images cannot be used for physical analysis, because the original information is lost. NIFS can connect universities at a speed of 1 G bps by Super SINET, and this speed is fast enough to send lossless motion images. The new system uses this network, and thereby can provide high-quality durable lossless images for scientific analyses.

Internet and intranet: a new theatre for surgical practice

Despite the technological breakthrough and commercial success of the Internet over the past decade, the web presence of surgery has been marginal and disorganised. Minimal utilisation of Internet applications is apparent in the average surgical practice, although the tools to make substantial improvements in gaining and providing information are readily available and often free of charge. With the widespread availability of broadband residential Internet access, streaming video technology providing high-quality full-screen video streams offers valuable educational potentials. Telemedicine and teleconferencing over the Internet are low-cost alternatives to other means of postgraduate training. In addition, an array of devices, utilising net technologies are presented, and with judicious use of these our efficacy and patient-care may be improved.

Streaming Video and Rich Media

MANY YEARS ago, I discovered that, when I went to a high-tech conference that was not designed for educators, I often learned more, at least about technology. I am not sure whether other sectors are ahead of education, whether we're just falling behind, or whether just getting out is what's helpful. So for years I have consciously tried to attend at least one conference a year that is aimed at and attended by such people as telecommunications experts, graphic artists, those who work in the entertainment industry, corporate trainers, business executives, representatives of the military/industrial complex, chip designers, robot builders, and so on. What I have discovered from this practice of mine is that, if you hang around only with educators, you learn to think only the way they do. Your world will be too small. I do have a suspicion as to why you see more advanced technology at noneducation conferences. My suspicion is that business, industry, and the military are much bigger markets than education. I also suspect that educational institutions tend not to be early adopters of the newest technology, which is what conferences and trade shows highlight. In addition to attending what might seem like some weird high-tech conferences, I also receive and read sundry journals, such as Sound & Communication, a magazine for system integrators; DV-Digital Video, a journal about high-tech video; Teleconference, a journal devoted to enterprise-wide collaboration; Network World, whose title tells it all; and Technology Review, a journal from MIT, which I strongly recommend. Recently, I received a new journal, Streaming 4 Business.1 And it is this journal that prompted me to write this column. The phrase is a specific term that usually refers to motion video with accompanying audio that is delivered live over the Internet; that is, a user doesn't have to download a file to a personal computer and then play it back. Maybe I am a pessimist, but for years I just could not see how it would ever be possible to stream video to most users reliably and with any consistency over the clogged Internet. Obviously, if you're on a go-fast university-based LAN, as I am, streaming video over the LAN is not a problem. Most people, however, do not have such a great Internet connection. Reading Streaming 4 Business, I learned how companies like Akamai are solving the technological problems and making streaming video work well. Akamai Technologies of Cambridge, Massachusetts (http://www.akamai.com), uses to help its customers solve the problem of distributing high-quality streaming video and other rich media to users around the world. Currently, Akamai has more than 4,200 servers in 50 countries running on 225 different telecommunications networks! The reason? If the video won't go from here to there reliably, just move the video to there. This sounds straightforward, but it would be terribly redundant to move all the video to all the servers. To solve this problem, Akamai uses a sophisticated map-based algorithm to predict where and when users will need certain video, which it then moves to an edge server that is as close to the user as possible. Akamai also takes a unique approach to solving the problem of different users having Internet connections with different bandwidths. Most people who encode and stream video typically encode the video for three different Internet connection speeds, such as 28-56 kb/s, 128 kb/s (ISDN speed), and 300+ kb/s (high-speed connection). When you receive one of these video streams, if the Internet gets clogged up, the video hesitates, and the frame rate drops to a frame a second or less. Typically the video window size remains the same. Akamai takes a different approach and just reduces the size of the video window. The idea is to keep the video quality high and sacrifice window size. I have not had a chance to try out this technology, but I am eager to do so. …

IP multicast of real-time MPEG over ATM

IP and ATM multicasting are compared, and current approaches for transporting IP multicast over ATM networks are reviewed. The use of ATM backbones to carry multiple high quality video streams is noted, and the relative strengths and weaknesses of ATM Forum LAN Emulation and recent IETF proposals for carrying IP multicast over ATM are discussed. An experimental application is described for multicasting multiple MPEG-1 video streams between routers connected over a live ATM campus network, and IP multicast services are noted as increasingly important and powerful in the development of the so-called Information Superhighway.