4,705 research outputs found
Towards SVC-based adaptive streaming in information centric networks
HTTP Adaptive Streaming (HAS) is becoming the de-facto standard for video streaming services. In HAS, each video is segmented and stored in different qualities. The client can dynamically select the most appropriate quality level to download, allowing it to adapt to varying network conditions. As the Internet was not designed to deliver such applications, optimal support for multimedia delivery is still missing. Information Centric Networking (ICN) is a recently proposed disruptive architecture that could solve this issue, where the focus is given to the content rather than to end-to-end connectivity. Due to the bandwidth unpredictability typical of ICN, standard AVC-based HAS performs quality selection sub-optimally, thus leading to a poor Quality of Experience (QoE). In this article, we propose to overcome this inefficiency by using Scalable Video Coding (SVC) instead. We individuate the main advantages of SVC-based HAS over ICN and outline, both theoretically and via simulation, the research challenges to be addressed to optimize the delivered QoE
Minimizing the impact of delay on live SVC-based HTTP adaptive streaming services
HTTP Adaptive Streaming (HAS) is becoming the de-facto standard for Over-The-Top video streaming services. Video content is temporally split into segments which are offered at multiple qualities to the clients. These clients autonomously select the quality layer matching the current state of the network through a quality selection heuristic. Recently, academia and industry have begun evaluating the feasibility of adopting layered video coding for HAS. Instead of downloading one file for a certain quality level, scalable video streaming requires downloading several interdependent layers to obtain the same quality. This implies that the base layer is always downloaded and is available for playout, even when throughput fluctuates and enhancement layers can not be downloaded in time. This layered video approach can help in providing better service quality assurance for video streaming. However, adopting scalable video coding for HAS also leads to other issues, since requesting multiple files over HTTP leads to an increased impact of the end-to-end delay and thus on the service provided to the client. This is even worse in a Live TV scenario where the drift on the live signal should be minimized, requiring smaller segment and buffer sizes. In this paper, we characterize the impact of delay on several measurement-based heuristics. Furthermore, we propose several ways to overcome the end-to-end delay issues, such as parallel and pipelined downloading of segment layers, to provide a higher quality for the video service
An Efficient Transport Protocol for delivery of Multimedia An Efficient Transport Protocol for delivery of Multimedia Content in Wireless Grids
A grid computing system is designed for solving complicated scientific and
commercial problems effectively,whereas mobile computing is a traditional
distributed system having computing capability with mobility and adopting
wireless communications. Media and Entertainment fields can take advantage from
both paradigms by applying its usage in gaming applications and multimedia data
management. Multimedia data has to be stored and retrieved in an efficient and
effective manner to put it in use. In this paper, we proposed an application
layer protocol for delivery of multimedia data in wireless girds i.e.
multimedia grid protocol (MMGP). To make streaming efficient a new video
compression algorithm called dWave is designed and embedded in the proposed
protocol. This protocol will provide faster, reliable access and render an
imperceptible QoS in delivering multimedia in wireless grid environment and
tackles the challenging issues such as i) intermittent connectivity, ii) device
heterogeneity, iii) weak security and iv) device mobility.Comment: 20 pages, 15 figures, Peer Reviewed Journa
Saving Energy in Mobile Devices for On-Demand Multimedia Streaming -- A Cross-Layer Approach
This paper proposes a novel energy-efficient multimedia delivery system
called EStreamer. First, we study the relationship between buffer size at the
client, burst-shaped TCP-based multimedia traffic, and energy consumption of
wireless network interfaces in smartphones. Based on the study, we design and
implement EStreamer for constant bit rate and rate-adaptive streaming.
EStreamer can improve battery lifetime by 3x, 1.5x and 2x while streaming over
Wi-Fi, 3G and 4G respectively.Comment: Accepted in ACM Transactions on Multimedia Computing, Communications
and Applications (ACM TOMCCAP), November 201
Architecture for Cooperative Prefetching in P2P Video-on- Demand System
Most P2P VoD schemes focused on service architectures and overlays
optimization without considering segments rarity and the performance of
prefetching strategies. As a result, they cannot better support VCRoriented
service in heterogeneous environment having clients using free VCR controls.
Despite the remarkable popularity in VoD systems, there exist no prior work
that studies the performance gap between different prefetching strategies. In
this paper, we analyze and understand the performance of different prefetching
strategies. Our analytical characterization brings us not only a better
understanding of several fundamental tradeoffs in prefetching strategies, but
also important insights on the design of P2P VoD system. On the basis of this
analysis, we finally proposed a cooperative prefetching strategy called
"cooching". In this strategy, the requested segments in VCR interactivities are
prefetched into session beforehand using the information collected through
gossips. We evaluate our strategy through extensive simulations. The results
indicate that the proposed strategy outperforms the existing prefetching
mechanisms.Comment: 13 Pages, IJCN
The effectiveness of the creativity trigger module in achieving higher levels of creative thinking among prospective teachers
The unoptimised level of creative thinking is seen as an issue among Semester 8 prospective teachers in Malaysian Teacher-Education Institutes (IPG). This could impede their teaching of creative thinking as one of the four components of 21st century skills in schools. In relation to this, this study sets out to investigate prior creativity levels of IPG prospective teachers and develop the Creativity Trigger Module (CTM) as a training module for enhancing their creativity. The Torrance Tests of Creative Thinking (TTCT) was used to compare the prior creativity levels of four respondent groups and test the effectiveness of the CTM on five dimensions of figural creativity, namely fluency, originality, elaboration, resistance to premature closure, abstractness of titles, and their overall creativity. A two-stage cluster sampling technique identified two IPGs with 68 respondents in the state of Johor namely, IPG-Kampus Tun Hussein Onn, Batu Pahat (IPGKTHO) as the control group site (34 respondents), and IPG- Kampus Temenggong Ibrahim, Johor Bahru (IPGKTI) as the treatment group site (34 respondents). Mathematics (MT) and Design and Technology (RBT) are the only two specialist subject combinations that provided enough sample size at both test sites. A quasi-experimental research design was used and this involved intact classes. Data analysis was carried out as follows: ANOVA, ANCOVA, and Wilcoxon Signed Rank Test analysis for TTCT scores while data analysis based on the NVivo software was used for the focus group interviews. Findings on prior creativity levels showed average or low creativity levels among all 4 test groups with IPGKTHO and RBT options having significantly higher posttest marks as compared to IPGKTI and MT option respectively. The CTM was found to improve significantly respondents’ posttest marks for the treatment group in all the five dimensions of figural creativity and, their overall creativity. Feedback from respondents revealed positive support for the CTM. In conclusion, the prior creativity of IPG prospective teachers was at an unoptimised level before treatment but the CTM has been successfully developed as an effective resource for enhancing the creative thinking levels among IPG prospective teachers
- …