Multimedia Quality of Experience

This chapter introduces the overall concept of multimedia Quality of Experience (QoE) over the Internet. It presents all the elements of multimedia QoE ecosystem and emphasizes their roles in determining the user satisfaction. The chapter also presents different multimedia transmission components and how these components contribute to successful transmission of the media content. In addition, some key performance indicators relevant to the multimedia QoE are presented with more emphasis on network and application level indicators. Furthermore, different QoE estimation methods and techniques along with QoS/QoE learning algorithms are presented. Finally, the chapter includes some of the future challenges and issues related to multimedia QoE.

Multimedia Transmission in Wireless Sensor Networks

Wireless sensor networks are an emerging technology that can provide valuable information for a large series of monitoring and control applications. Comprising many monitoring scenarios with different particularities, as industrial management, weather forecasting, home automation, traffic management and rescue operations, just to cite a few, wireless sensor networks bring many possibilities for innovative applications that cannot be addressed by conventional wireless network technologies. When sensors are equipped with cameras or microphones, multimedia data can be retrieved from the monitored field, enriching the perception of the target area. However, the constrained nature of wireless sensor networks imposes many challenges to multimedia transmission, fostering development of optimized protocols. In this chapter, we present the state of the art of multimedia transmission in wireless sensor networks, covering topics as routing, error control, congestion avoidance, real-time delivery, compression and QoS, potentially supporting in the development of wireless multimedia sensor networks.

A Review of the Digital Cinema Chain

This chapter deals with digital cinema chain as digital cinema (DC) offers an enhanced viewing experience for audiences, content flexibility, and distribution cost savings. Taking into account that the transition from physical media to electronic one represents a paradigm shift in video compression techniques and applications, archival requirements have been analyzed. A brief overview of the DC specification has been provided as was also discussed how JPEG 2000 was utilized within this specification. The current status of digital cinema was surveyed with a focus on the compression part of the DC system. To make the system practical and economic, various coding techniques have been applied to compress DC data for archive and distribution purposes. Standardization process for archival applications is considered. Features used for shot cut detection that are robust against the artifacts in film material have also been presented.

Multiple Description Coding for Multipath Video Streaming

This Chapter addresses robust video coding and adaptation of compressed streams in multipath communications environments, using Multiple Description Coding (MDC). A review of Multiple Description (MD) video coding is presented, covering different video coding approaches. Different path diversity topologies and MDC networking applications are described, including MD video adaptation schemes to operate at network edges, for robust video streaming. A multi-loop architecture for Advanced Video Coding (AVC) to prevent drift distortion accumulation is also described. A simulation study of MDC for AVC is presented to evaluate the coding efficiency, the effects of distortion propagation and streaming performance in lossy networks. These research findings extend the current state-of-the-art MDC methods by developing new networking capabilities in different application scenarios maintaining coding efficiency, and increasing error robustness, when subject to transmission losses.

QoE Measurements and Analysis for VoIP Services

Quality of Service (QoS) and Quality of Experience (QoE) are two different approaches that evaluate the quality level of a given service. In general, QoS models analyze objective network parameters, while QoE techniques focus on what the user actually perceives when consuming the service (subjective perspective). In this chapter, it is presented a comparative study of two voice codecs employed by two well-known VoIP applications, namely Skype and Jitsi, analyzing the provided quality from two perspectives: objective and subjective evaluations. To this end, several network metrics have been taken into account; in addition, the participants in this study completed different quality surveys in order to obtain their opinion about the evaluated services. Concretely, 60 quality tests with 60 subjects have been performed in a controlled wired scenario. The obtained results suggest a clear relationship between QoS and QoE. This chapter aims to present a detailed description about the process to perform comparative quality evaluations of multimedia services from both QoS and QoE perspectives.

Quality of Experience Factors for Mobile TV Users

This chapter helps the professionals involved in the Mobile TV industry to methodically engineer the Quality of Experience (QoE) of Mobile TV users. Its objective is to investigate the factors that influence the QoE of Mobile TV users. It also discusses the issues for strategic implications for the Mobile TV industry. We retrieved and categorized the majority of the critical works focusing on QoE for Mobile TV users. Then, we considered them and proposed a comprehensive road-map for improving the QoE of Mobile TV users. We present an approach to produce improvements to the Mobile TV customer experiences. This chapter proposes a seven-stage “road-map” to improvement, which develops the existing models. This study remains to be seen how the presented QoE factors– both amongst technologies and Mobile TV actors – will affect the potential for Mobile TV amongst various types of users. The proposed road-map can help to bridge gaps between other studies that have either focused on QoE for mobile TV or have addressed frameworks for mobile TV.

Video Broadcasting Protocol for Streaming Applications with Cooperative Clients

Video broadcasting is one of the efficient methods in implementing large-scale video-on-demand (VoD) systems. Managing large number of concurrent channels in a video server is the main barrier to implement Harmonic Broadcast (HB) in VoD applications. In this chapter, we propose a new transmission protocol denoted as Harmonic-Based Peer-to-Peer Broadcasting (HPB) to release the burden of HB by dispersing a large portion of workload over a number of clients denoted peer servers. As the bandwidth requirement of each segment in HB is different, we first develop a segment placement algorithm to balance the workload among peer servers. We then study the dynamic nature of peer-to-peer (P2P) paradigm on the design of the system. An analytical model is developed to determine the optimal number of peer servers required for the system under certain level of availability such that the workload of the central server can reach a target level. The results show that the workload of central server can be significantly reduced.

Media Synchronization Control in Multimedia Communication

In this chapter, first, we explain media synchronization control. Next, we make a survey of media synchronization control techniques and classify the techniques. Also, we compare group synchronization control schemes. Then, we propose new control called the dynamic local lag control in joint musical performance which has severe requirements on high quality of media synchronization and high interactivity. In the performance, multiple users play their respective same or different types of musical instruments together. However, the media synchronization quality and interactivity may seriously be deteriorated owing to the network delay. By Quality of Experience (QoE) assessment, we demonstrate that the new control can achieve high quality of media synchronization and keep the interactivity high. Finally, we discuss the future directions of media synchronization control.

Next Steps in Multimedia Networking

This chapter presents in brief background knowledge on multimedia communication: multimedia applications and services, network and user QoS requirements, bandwidth on demand, multicasting, media synchronization, adaptive media coding, multimedia streaming, and end-system support for multimedia communication. In the second part, it deals with content delivery networks (CDNs). In the third part, it concentrates on issues for achieving multimedia optimization over heterogeneous wireless and wired networks. In the fourth part, it presents the main approaches for QoS guarantees over the Internet. This part tries to include the important aspects that have significantly impacted the enhancements to the basic Internet architecture and its associated protocols. In the fifth part, the chapter presents future Internet architectures. This is followed by some future research directions in multimedia networking.

Facilitating Open Source Software and Standards to Assembly a Platform for Networked Music Performance

This chapter presents our efforts towards developing a Networked Music Performance (NMP) system by tailoring and re-using open source software components. The chapter builds on the assumption that NMP and videoconferencing systems share common properties for real-time bidirectional media interaction. It is acknowledged that although NMP is a form of videoconferencing, it is a lot more demanding with respect to efficient distribution of network resources allowing fast and reliable communication of audio and video streams. Initially, an overview of NMP research is provided and the design criteria of NMP system development are clearly delineated. Following, the chapter describes the network protocols involved in videoconferencing. Then, a number of relevant open source software initiatives implementing these protocols are presented and compared for their suitability for NMP system development. Finally, the chapter describes a baseline NMP platform that can serve as a testbed for further research on distributed ensemble performance and remote musical interactions.