Guest Editorial
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| Title | Guest Editorial |
| Authors | |
| Abstract | Since the turn of this century, we have witnessed the growing deployment of broadband networks and the growing convergence of voice, image, video, and data. We have also seen that the rising demand for quality service by consumers has expedited the advance of multimedia computing and communication technologies, ranging from video coding, communication infrastructure, content distribution protocols, quality of service (QoS) and quality of experience (QoE) management, visual content analysis, post-processing, to interactive models. Novel video source and channel coding techniques such as scalable video coding, multiple description codes, transcoding, and network coding help improve the efficiency of video transmission, whereas innovative communication architectures such as overlay networks, content delivery networks (CDN), and peer-to-peer (P2P) distributed networks greatly enhance the efficacy of video distribution. All these developments have created unprecedented benefits for the user. For example, IPTV over managed IP networks not only holds the promise for high quality video viewing experience that is at least as good as what is offered by todays cable/satellite TV, but also introduces new service functionalities such as time-shift viewing and interactivity. The IP multimedia subsystem (IMS) provides a unified framework for multimedia service creation and deployment and supports interoperability and network convergence. Last but not the least, new wireless network technologies and video delivery mechanisms such as IEEE 802.11 (Wi-Fi) and the 3G and 4G cellular systems are becoming strong alternatives to their wired counterparts, allowing users to access and produce video at any time and from anywhere.In view of these advances in modern multimedia applications and services, this special issue is dedicated to multimedia computing and communications, in particular, to technologies addressing the challenges arising out of the limited computational power of client devices, the explosive growth of rich media, the complexity of content analysis and understanding, and the heterogeneity of the transport networks. In the following, we briefly summarize the papers included in this special issue. IPTV: An End to End Perspective. Marie-Jośe Montpetit, Thomas Mirlacher, and Michael Ketcham provide an end-to-end overview of IPTV. IP video has taken two forms: Internet Protocol Television (IPTV), which emulates broadcast Television and is delivered over a managed IP network, and Internet video, where video selections are accessed across the best effort Internet. IPTV has witnessed a rapid evolution in its short history. The focus of this survey paper is the argument that IPTV and other IP video services are in a co-evolutionary feedback loop, where commercial IPTV standardizes and supports new technologies for marketing and delivering IP media, while complementary IP services bring about “anywhere” Internet access and Web-based interactivity to IPTV. This paper gives a tutorial-level overview of how IPTV content is managed and delivered today, and discusses the impacts of transformations in IPTV that are enhanced by Internet and Web capabilities on the IPTV architecture and media value chain.Media-Oriented Service Composition with Service Overlay Networks: Challenges, Approaches and Future Trends. In this paper, JongWon Kim, Sang Woo Han, Dong-Hoon Yi, Namgon Kim, and C.-C. Jay Kuo provide a survey on the challenges, approaches, and future trends of media-oriented service composition with service overlay networks. This topic is very important in light of the gradually-increasing demand for the fused interaction of media-oriented service composition and overlay-based network support, which interaction enables many new types of customized media services based on the diverse demand of end users. The resulting effective and differentiated networking support will become one of the most important requirements of the network infrastructure in the future. In this paper, the authors first present the emerging trend on the interaction of media-oriented service composition and overlay-based networks by introducing related technical issues. They then describe the top-down and the bottom-up approaches that coordinate service mapping using the service overlay networks (SONs) and provisioning resources for them, respectively. Finally, they examine latest research on futuristic overlay networks for service realization.Performance Evaluation of Rate-Control Strategies for Real-Time Systems Over a Rate-Varying Channel. Ajmal Muhammad, Peter Johansson, and Robert Forchheimer look into the issue of the buffer position and its impacts on two real-time systems for video/audio communication over rate-varying channels. A buffer is placed before the rate-controlled encoder in one system, and after the encoder in the other system. They evaluate the system performance in terms of SNR versus end-to-end delay for both deterministic rate-varying channels and stochastic rate-varying channels. They find that, contrary to intuition, one of the systems performs better than the other. In addition to the use of analytic analysis for the system performance comparison, the authors also validate the comparison through simulations.A Parallel-Layered Belief-Propagation Decoder for Non-layered LDPC Codes. Kun Guo, Shushan Qiao and Yong Hei propose a Parallel-Layered Belief-Propagation (PLBP) algorithm which makes use of a layered decoding algorithm on the “non-layered” quasi-cyclic (QC) LDPC codes, whose column weights are higher than one within layers. The authors show that not only their algorithm achieves a better performance to cope with errors, but also requires significantly smaller number of iterations when compared to state of the art. The paper then details a low-power partial parallel decoder architecture based on the proposed algorithm, resulting in better energy efficiency. In a case study, a multi-rate 9216-bit LDPC decoder is implemented dissipating an average power of 87mW with 10 iterations at a 2 clock frequency of 83.3 MHz.A Framework for Robust Audio Fingerprinting. Carlo Bellettini and Gianluca Mazzini investigate how to reliably and efficiently recognize audio in vast digital music archive. They tackle this problem by using audio fingerprinting. In this paper they present a framework for audio fingerprinting with a focus on broadcast monitoring applications. They have implemented a robust fingerprinting algorithm and a suitable retrieval method and proposed a number of effective strategies to improve both the reliability and the speed of the overall system. The experiments are carried out based on a database of 100,000 songs. The discussions provided in this paper can help readers to get a better understanding of not only the topic, but also the practical design issues of such systems.The area of multimedia computing and communications being so broad, we can only cover a limited number of papers in this special issue. However, these papers have addressed a good range of topics from IPTV architecture to media oriented service composition, from the study of video/audio communication system to audio recognition. We hope the two survey papers can give readers a high-level overview of the state-of-the-art technologies, challenges, and trends concerning IPTV and media oriented service composition. We also hope the other three research papers can sparkle further research in both theoretical and practical aspects of the relevant topics.We would like to send our sincere thanks to the reviewers who provided the authors with critically important, timely and highly constructive feedbacks. We also thank the staff at the JCM Academy Publisher for their efficient job in handling the manuscripts. Last but not the least, our genuine gratitude goes to the Associate Editor-in-Chief of the JCM Journal of Communications, Dr. Haohong Wang, for his assistance with this special issue. |
| Publisher | ACADEMY PUBLISHER |
| Date | 2010-05-01 |
| Source | Journal of Communications Vol 5, No 5 (2010): Special Issue: Multimedia Computing and Communications |
| Rights | Copyright © ACADEMY PUBLISHER - All Rights Reserved.To request permission, please check out URL: http://www.academypublisher.com/copyrightpermission.html. |