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1.
An important research issue in video streaming is how to efficiently utilize the network resources to provide clients instant
access to multiple video objects. Caching strategy and transmission scheme are the two essential points inside the video streaming
framework. Recent research efforts on them are not sufficient due to their inflexible support for scalable encoded video streams
and heterogeneous requests from clients. In this paper, we propose an optimized caching strategy (OCS) and a scalable transmission
scheme (STS) for scalable coded video streaming. By exploring the characteristics of video streaming workload and system design
objectives, OCS and STS work efficiently to minimize both network bandwidth cost and user access latency. Firstly, we analyze
the caching problem for the proxy-assisted video streaming system and derive a maneuverable caching scenario. Secondly, we
develop an efficient transmission scheme for scalable coded videos. Thirdly, we formulate a multi-objective optimization model
with closed-form expressions to obtain the optimized caching strategy. Finally, with designed algorithms, an excellent compromise
between two competing objectives (minimizing the bandwidth cost and the access latency) is achieved. We start our evaluation
by studying the optimized caching strategy for a single video object. Then we apply the strategy to multiple video objects
and illustrate the tradeoff between the optimization objectives. Our evaluation results show that compared with other caching
strategies, the proposed optimized scalable caching strategy can achieve a significant reduction in bandwidth cost with even
a small proxy cache size. Meanwhile, the best performance (in terms of bandwidth cost) is obtained together with the proposed
scalable batch-patching transmission scheme.
相似文献
Kenneth OngEmail: |
2.
A video streaming proxy server needs to handle hundreds of simultaneous connections between media servers and clients. Inside,
every video arrived at the server and delivered from it follows a specific arrival and delivery schedule. While arrival schedules
compete for incoming network bandwidth, delivery schedules compete for outgoing network bandwidth. As a result, a proxy server
has to provide sufficient buffer and disk cache for storage, together with memory space, disk space and disk bandwidth. In
order to optimize the throughput, a proxy server has to govern the usage of these resources. In this paper, we first analyze
the property of a traditional smoothing algorithm and a video staging algorithm. Then we develop, based on the smoothing algorithm,
a video staging algorithm for video streaming proxy servers. This algorithm allows us to devise an arrival schedule based
on the delivery schedule. Under this arrival and delivery schedule pair, we can achieve a better resource utilization rate
gracefully between different parameter sets. It is also interesting to note that the usage of the resources such as network
bandwidth, disk bandwidth and memory space becomes interchangeable. It provides the basis for inter-resource scheduling to
further improve the throughput of a video streaming proxy server system.
相似文献
Daniel P. K. LunEmail: |
3.
Large scale video streaming over the Internet requires a large amount of resources such as server I/O bandwidth and network
bandwidth. A number of video delivery techniques can be used to lower these requirements. Periodic broadcast by a central
server combined with proxy caching offers a significant reduction of the aggregate network and server I/O bandwidth usage.
However, the resources available to a single server are still limited. In this paper we propose a system with multiple geographically distributed servers. The problem of multiple servers for periodic broadcast is quite different from the problem of object location for multiple
web servers. Multiple servers offer increased amount of resources and service availability and may potentially allow a further
reduction of network bandwidth usage. On the other hand, the benefit of periodic broadcast mostly comes from high demand videos.
With multiple servers holding a video, the demand of the video at each server is reduced. Therefore, it is a challenge to
use multiple servers efficiently. We first analyze the dependence of the resource requirements on the number and locations
of the servers. Based on the character of the function describing such a dependence, we formulate and solve the problem of
video location and delivery, in a way that minimizes resource usage. We explore a trade-off between network and I/O bandwidth
requirements. We evaluate our proposed solutions through a number of tests.
相似文献
David H. C. DuEmail: |
4.
Service replication is an effective way to address resource requirements and resource availability problem. Dynamic service
selection enables clients to choose a server offering the best performance. Proper server selection is especially important
for video streaming over the Internet due to its high bandwidth requirements. However, given the length of a typical video
transmission, the server priorly selected may no longer be an optimal one for the duration of the entire transmission. More
importantly, a server may fail during the transmission of a video. In this paper we examine the possibility of switching to
another server during an on-going transmission for Periodic Broadcast schemes. Due to the timing requirements typical for
Periodic Broadcast the server switch may cause playback disruptions. We analyze the magnitude of the problem and propose an
easy to implement solution. We define the criteria, additional to the bandwidth availability for example, according to which
a new server should be selected. The client is also required to delay its playback by the amount of time bounded by the server
transmission offset. In addition, we propose an alternative method to ensure uninterrupted playback that relies on proxy caching.
Simulation results show that our approach can significantly reduce the likelihood of playback disruptions.
相似文献
David H. C. DuEmail: |
5.
A survey on peer-to-peer video streaming systems 总被引:2,自引:1,他引:2
Video-over-IP applications have recently attracted a large number of users on the Internet. Traditional client-server based
video streaming solutions incur expensive bandwidth provision cost on the server. Peer-to-Peer (P2P) networking is a new paradigm
to build distributed network applications. Recently, several P2P streaming systems have been deployed to provide live and
on-demand video streaming services on the Internet at low server cost. In this paper, we provide a survey on the existing
P2P solutions for live and on-demand video streaming. Representative P2P streaming systems, including tree, multi-tree and
mesh based systems are introduced. We describe the challenges and solutions of providing live and on-demand video streaming
in P2P environment. Open research issues on P2P video streaming are also discussed.
相似文献
Chao LiangEmail: |
6.
Pradeep K. Atrey Wei-Qi Yan Mohan S. Kankanhalli 《Multimedia Tools and Applications》2007,34(1):107-135
This paper addresses the problem of ensuring the integrity of a digital video and presents a scalable signature scheme for
video authentication based on cryptographic secret sharing. The proposed method detects spatial cropping and temporal jittering
in a video, yet is robust against frame dropping in the streaming video scenario. In our scheme, the authentication signature
is compact and independent of the size of the video. Given a video, we identify the key frames based on differential energy
between the frames. Considering video frames as shares, we compute the corresponding secret at three hierarchical levels.
The master secret is used as digital signature to authenticate the video. The proposed signature scheme is scalable to three
hierarchical levels of signature computation based on the needs of different scenarios. We provide extensive experimental
results to show the utility of our technique in three different scenarios—streaming video, video identification and face tampering.
相似文献
Mohan S. KankanhalliEmail: |
7.
R. Venkatesh Babu Andrew Perkis Odd Inge Hillestad 《Multimedia Tools and Applications》2008,37(2):211-231
This paper deals with monitoring user perception of multimedia presentations in a Universal Multimedia Access (UMA) enabled
system using objective no-reference (NR) metrics. These NR metrics are designed for an UMA-enabled system, in a novel architecture,
for a multimedia viewer. The first metric measures block-edge impairments in a video frame at the receiver end, based on the
observation that they occur in regions with low spatial activity. The second metric evaluates the quality of the reconstructed
video frame in the event of packet loss. Here, the structure of the artifact is itself exploited for the evaluation. Both
the metrics involve low computational complexity and are feasible for real-time monitoring of streaming video in a multimedia
communication scenario. Further, in rate-adaptive streaming of video, these metrics could serve as feedback parameters to
dynamically adapt the bit rates based on network congestion.
相似文献
Odd Inge HillestadEmail: |
8.
Many overlay multicast schemes have been proposed recently at the application level to support video-on-demand service over
the Internet. With the proliferation of mobile devices and the increasing coverage of high speed wireless networks, such services
are likely to be extended to support clients connected to the Internet through a wireless last hop. However, existing application
level multicast schemes are not designed to handle the characteristics of the noisy wireless links. In this paper we propose
an overlay multicast scheme called Quick Patching which arranges additional patch streams to clients under poor link conditions
to improve their clients’ viewing quality. We demonstrate through extensive simulation experiments that Quick Patching is
not only scalable, but can also sustain the required viewing quality under different network conditions including fluctuating
error conditions as well as heterogeneous user viewing quality requirements.
相似文献
Edward ChanEmail: |
9.
P-chaining: a practical VoD service scheme autonomically handling interactive operations 总被引:1,自引:1,他引:0
Providing scalable VoD streaming services has recently become a hot issue, and many approaches have been proposed. Because
video streaming services through the Internet are widely used, the need to support VCR operations also increases. However,
there are few approaches to supporting VCR operations on the Internet. We propose a service scheme based on chaining, in which
clients as well as the server provide streaming services. In the proposed scheme, services are provided by unicast and managed
locally using node lists. In addition, our scheme can support frequent VCR operations without incurring significant overhead
in the server workload. We have evaluated our scheme through simulation with real traces from a content distribution network
(CDN) company and with various parameters. The results show that the proposed scheme reduces server workload significantly.
The results also verify that frequent VCR operations can be served smoothly without causing too much overhead.
相似文献
Heon Y. YeomEmail: |
10.
Abdulmotaleb El Saddik Abdur Rahman Souhail Abdala Bogdan Solomon 《Multimedia Tools and Applications》2008,39(3):353-377
PECOLE (Peer-to-pEer COLlaborative Environment) is a fully decentralized multimedia collaborative environment that supports
a wide range of collaborative multimedia applications, including chat, shared browsing, shared telepointer, multipoint-to-multipoint
audio/video conferencing and multilingual collaboration. PECOLE can intelligently run on very constrained resources, is highly
resilient, scalable and does not rely on dedicated servers. Instead, PECOLE is built upon a Peer-to-Peer (P2P) overlay network,
using SUN’s JXTA framework and SWT technology. In this paper, we present the architecture and implementation of PECOLE with
the performance results of the tests we conducted.
相似文献
Bogdan SolomonEmail: |
11.
Peer to peer video streaming in Bluetooth overlays 总被引:2,自引:2,他引:0
As Bluetooth is available in most personal and portable terminals (eg, cellular phone, PDA, videocamera, laptop, etc) Peer-to-peer
video streaming through Bluetooth networks is now a reality. Camera equipped Bluetooth phones capture video and broadcast
it to other Bluetooth devices and to the infrastructure. Tra ditionally, large scale Bluetooth networks were designed using
scatternet concepts. However, many Bluetooth devices do not support Scatternet connections and, even if they support it, they
provide only very limited features suitable mostly for static environments. In high mobility situations, a traditional Scatternet
design is not useful because of frequent disconnections and reconnections. To overcome these problems, we propose overlaid
Bluetooth Piconets (OBP) and simplified overlaid Bluetooth Piconets (SOBP) that interconnect Piconets forming virtual Scatternets.
In OBP, every Piconet dynamically reconfigures to collect metadata from neighboring Piconets. If metadata shows the existence
of useful data to transfer, an inter-Piconet connection is made to carry out the transfer. SOBP can be used instead of OBP
once neighbor Piconets have already discovered each other. In this paper, we compare via analysis and simulation the throughput
and efficiency of OBP, SOBP and Scatternet for video applications. We demonstrate the feasibility of video over OBP and SOBP
for a representative application.
相似文献
Mario GerlaEmail: |
12.
In this paper, an adaptive framework for video streaming over the Internet is presented. The framework is a joint design of
packet scheduling and rate control with optimal bandwidth resource allocation. The transmission rate is dynamically adjusted
to obtain maximal utilization of the client buffer and minimal allocation of the bandwidth. Under the constraint of the transmission
rate, a prioritized packet scheduling is designed to provide a better visual quality of video frames. The packet scheduling
is a refined bandwidth allocation which takes into account of varying importance of the different packets in a compressed
video stream. Moreover, the proposed approach is scalable with increasing multimedia flows in the distributed Internet environment.
Comparisons are made with the most current streaming approaches to evaluate the performance of the framework using the H.264
video codec. The extensive simulation results show that the average Peak Signal to Noise Ratio (PSNR) increases in our proposed
approach. It provides a better quality of the decoded frames, and the quality of the decoded frames changes more smoothly.
The achieved video quality among different users also has a lower fluctuation, which indicates a fair sharing of network resources.
相似文献
Shu-Ching ChenEmail: |
13.
This work investigates the modeling of aggregate available bandwidth in multi-sender network applications. Unlike the well-established
client–server model, where there is only one server sending the requested data, the available bandwidth of multiple senders
when combined together does exhibit consistent properties and thus can be modeled and estimated. Through extensive experiments
conducted in the Internet this work proposed to model the aggregate available bandwidth using a normal distribution and then
illustrates its application through a hybrid download-streaming algorithm and a playback-adaptive streaming algorithm for
video delivery under different bandwidth availability scenarios. This new multi-source bandwidth model opens a new way to
provide probabilistic performance guarantee in best-effort networks such as the Internet, and is particularly suitable for
the emerging peer-to-peer applications, where having multiple sources is the norm rather than the exception.
相似文献
Jack Y. B. LeeEmail: |
14.
Meng-Yen Hsieh Yueh-Min Huang Tzu-Chinag Chiang 《Multimedia Tools and Applications》2007,34(2):155-177
Mobile ad hoc networks without centralized infrastructure change their topology rapidly because of node mobility, making multimedia
applications difficult to run across wireless networks. Moreover, video transmission over ad hoc networks causes frequent
transmission loss of video packets owing to end-to-end transmission with a number of wireless links, and requires essential
bandwidth and restricted delay to provide quality-guaranteed display. This paper presents an architecture supporting transmission
of multiple video streams in ad hoc networks by establishing multiple routing paths to provide extra video coding and transport
schemes. This study also proposes an on-demand multicast routing protocol to transport layered video streams. The multicast
routing protocol transmits layered video streaming based on a weight criterion, which is derived according to the number of
receivers, delay and expiration time of a route. A simulation is performed herein to indicate the viability and performance
of the proposed approach. The simulation results demonstrate that the proposed transport scheme is more effective than other
video transport schemes with single or multiple paths.
相似文献
Tzu-Chinag ChiangEmail: |
15.
Streaming of scalable h.264 videos over the Internet 总被引:1,自引:0,他引:1
Aylin Kantarcı 《Multimedia Tools and Applications》2008,36(3):303-324
To investigate the benefits of scalable codecs in the case of rate adaptation problem, a streaming system for scalable H.264
videos has been implemented. The system considers congestion level in the network and buffer status at the client during adaptation
process. The rate adaptation algorithm is content adaptive. It selects an appropriate substream from the video file by taking
into account the motion dynamics of video. The performance of the system has been tested under congestion-free and congestion
scenarios. The performance results indicate that the system reacts to congestion properly and can be used for Internet video
streaming where losses occur unpredictably.
相似文献
Aylin KantarcıEmail: |
16.
P2P Object-based adaptivE Multimedia Streaming (POEMS) 总被引:1,自引:0,他引:1
Peer-to-peer (P2P) paradigm has recently gained tremendous attraction and is widely used for content distribution and sharing.
The future multimedia communication applications have to support the user’s needs, the terminal capabilities, the content
specification and the underlying networking technologies. They should be network-aware, topology-aware, and end-user-centric.
Thus, in this paper, we use the characteristics of the object-based encoding scheme and P2P network topology to propose adaptive
content delivery architecture for P2P networks. We propose an efficient mechanism for transmission of real-time content over
P2P networks, called POEMS (P2P Object-based adaptivE Multimedia Streaming). This object-based audio-visual quality adaptive
mechanism over P2P networks is media-aware, network-aware, and user-centric that is carried-out through (1) selection of appropriate
sending peers willing to participate in the streaming mechanism, (2) organization of sending peers by constructing an overlay
network to facilitate content delivery and adaptation, (3) dynamicity management of peers when some peer enters or leaves
the system to maintain an acceptable level of perceived video quality, and (4) ensuring the end-to-end QoS (Quality of Services)
by orchestrating the overall streaming mechanism. The obtained results demonstrate that combining content adaptation using
object-based encoding and advance network-aware peers selection based on peer monitoring leads to intelligent, efficient,
and large-scale support of multimedia services over complex network architectures.
相似文献
Mubashar MushtaqEmail: |
17.
Combining the advantages of Peer-to-Peer (P2P) content distribution concept and metadata driven adaptation of videos in compressed
domain, in this paper, we propose a simple but scalable design of distributed adaptation and overlay streaming using MPEG-21
gBSD, called DAg-stream. The objective is not only to shift the bandwidth burden to end participating peers, but also to move
the computation load for adapting video contents away from dedicated media-streaming/adaptation servers. It is an initiative
to merge the adaptation operations and the P2P streaming basics to support the expansion of context-aware mobile P2P systems.
DAg-stream organizes mobile and heterogeneous peers into overlays. For each video, a separate overlay is formed. No control
message is exchanged among peers for overlay maintenance. We present a combination of infrastructure-centric and application
end-point architecture. The infrastructure-centric architecture refers to a tree controller, named DAg-master, which is responsible
for tree/overlay administering and maintenance. The application end-point architecture refers to video sharing, streaming
and adaptation by the participating resourceful peers. The motivation for this work is based on the experiences and lessons
learned so far about developing a video adaptation system for heterogeneous devices. In this article, we present our architecture
and some experimental evaluations supporting the design concept for overlay video streaming and online adaptation.
Razib Iqbal is pursuing his Ph.D. degree in Computer Science at the University of Ottawa (uOttawa), Canada. His current research interests include — Distributed and online video adaptation, and video watermaking. Mr. Iqbal received his Masters and Bachelors degree, both in Computer Science, from uOttawa in 2006 and North South University, Bangladesh in 2003 respectively. He is a recipient of the uOttawa International Admission Scholarship for both his Masters and Ph.D. studies. Shervin Shirmohammadi Associate Professor at the School of Information Technology and Engineering, University of Ottawa, Canada, joined the University as an Assistant Professor in 2004, after 4 years of industry experience as a Senior Software Architect and Project Manager that followed his Ph.D. degree in Electrical Engineering from the same University in 2000. His current research interests include Massively Multiuser Online Gaming (MMOG) and Virtual Environments, Application Layer Multicasting and Overlay Networks, Adaptive P2P Audio/Video Streaming, and Multimedia Assisted Rehabilitation Engineering. In addition to his academic publications, which include two Best Paper Awards, he has over a dozen technology transfers to the private sector. He is Editor-in-Chief of the International Journal of Advanced Media and Communications, Associate Editor of ACM Transactions on Multimedia Computing, Communications, and Applications, Associate Editor of Springer's Journal of Multimedia Tools and Applications, and also chairs or serves on the program committee of a number of conferences in multimedia, virtual environments and games, and medical applications. Dr. Shirmohammadi is a University of Ottawa Gold Medalist, a licensed Professional Engineer in Ontario, a Senior Member of the IEEE, and a Professional Member of the ACM. 相似文献
Shervin ShirmohammadiEmail: |
Razib Iqbal is pursuing his Ph.D. degree in Computer Science at the University of Ottawa (uOttawa), Canada. His current research interests include — Distributed and online video adaptation, and video watermaking. Mr. Iqbal received his Masters and Bachelors degree, both in Computer Science, from uOttawa in 2006 and North South University, Bangladesh in 2003 respectively. He is a recipient of the uOttawa International Admission Scholarship for both his Masters and Ph.D. studies. Shervin Shirmohammadi Associate Professor at the School of Information Technology and Engineering, University of Ottawa, Canada, joined the University as an Assistant Professor in 2004, after 4 years of industry experience as a Senior Software Architect and Project Manager that followed his Ph.D. degree in Electrical Engineering from the same University in 2000. His current research interests include Massively Multiuser Online Gaming (MMOG) and Virtual Environments, Application Layer Multicasting and Overlay Networks, Adaptive P2P Audio/Video Streaming, and Multimedia Assisted Rehabilitation Engineering. In addition to his academic publications, which include two Best Paper Awards, he has over a dozen technology transfers to the private sector. He is Editor-in-Chief of the International Journal of Advanced Media and Communications, Associate Editor of ACM Transactions on Multimedia Computing, Communications, and Applications, Associate Editor of Springer's Journal of Multimedia Tools and Applications, and also chairs or serves on the program committee of a number of conferences in multimedia, virtual environments and games, and medical applications. Dr. Shirmohammadi is a University of Ottawa Gold Medalist, a licensed Professional Engineer in Ontario, a Senior Member of the IEEE, and a Professional Member of the ACM. 相似文献
18.
The MPEG-4 fine granularity scalability (FGS) video coding standard offers flexible adaptation to varying network bandwidths
and different application needs. This paper presents a MPEG-4 FGS video CODEC based watermarking scheme to embed watermark
during encoding. Watermark is embedded into base layer, and can be extracted from both base layer and enhanced video through
eliminating the influence of enhancement layer on watermark. This scheme eliminates error propagation caused by watermark
for normal video, and utilizes error propagation caused by watermark adjustment to protect the video content. This scheme
provides dual protection for intellectual property rights (IPR): watermark and video content protection utilizing error propagation
in temporal motion compensation prediction. Watermark is embedded into I-VOP, and is adjusted before I-VOP is reconstructed
as reference VOP. Only customers with authorization can adjust the watermark correctly during decoding to get good video quality.
Illegal customers can also access the video, but with bad quality. This scheme has the virtue of providing dual protection
with a little expense. Theoretical bounds of watermark embedding strength to keep watermark invisibility and of watermark
adjustment strength to get enough protective effect are calculated. Some experimental results are given and analyzed.
相似文献
Xingbin BianEmail: |
19.
Marco Tomassini Leslie Luthi Mario Giacobini William B. Langdon 《Genetic Programming and Evolvable Machines》2007,8(1):97-103
The genetic programming bibliography aims to be the most complete reference of papers on genetic programming. In addition
to locating publications, it contains coauthor and coeditor relationships which have not previously been studied. These reveal
some similarities and differences between our field and collaborative social networks in other scientific fields.
相似文献
Marco TomassiniEmail: |
20.
Television daily produces massive amounts of videos. Digital video is unfortunately an unstructured document in which it is
very difficult to find any information. Television streams have however a strong and stable but hidden structure that we want
to discover by detecting repeating objects in the video stream. This paper shows that television streams are actually highly
redundant and that detecting repeats can be an effective way to detect the underlying structure of the video. A method for
detecting these repetitions is presented here with an emphasis on the efficiency of the search in a large video corpus. Very
good results are obtained both in terms of effectiveness (98% in recall and precision) as well as efficiency since one day
of video is queried against a 3 weeks dataset in only 1 s.
相似文献
Patrick GrosEmail: |