Design and implementation of a synchronization scheduler in a distributed multimedia presentation system

A distributed multimedia document presentation involves retrieval of objects from one or more servers and their presentations at a client system. The retrieval and presentation of media objects have to be carried out in accordance with some temporal specification, i.e. temporal synchronization. In this thesis, we design and implement a synchronization scheduler in a distributed multimedia presentation system. First, we develop an interval constraint graph model to describe the temporal relationships among media objects. Second, based on the model, we give a way to produce an optimal schedule from a set of constraints using a linear programming solver. Third, we develop a run time rescheduling strategy to correct dynamic synchronization errors by means of a retiming method. Finally, we implement the scheduler in a simulated distributed environment to demonstrate its usefulness and effectiveness. The interval constraint graph model we developed takes into account the QoS of temporal constraints of a multimedia document. Our flexible temporal model can help to derive an optimal schedule and carry out run time rescheduling. Then, a multimedia document can be presented with better qualities of temporal constraints, or leading to a better presentation

Perceived synchronization of olfactory multimedia

This is the post-print version of this Article. The official published version can be accessed from the link below - Copyright @ 2010 IEEEThe concept of synchronization is of fundamental importance in multimedia systems and applications. The focus of this this paper is on olfaction-enhanced multimedia, which concerns itself with associating computer-generated smell with other media. However, the lingering nature of smell, as opposed to the transitory nature of other media objects that multimedia applications are accustomed to, such as video and audio, means that specific attention needs to be given when synchronizing other media content with olfactory data. Consequently, this paper presents the results of an experimental study carried out to explore and investigate the temporal boundaries within which olfactory-data output in an olfaction-enhanced multimedia application can be successfully synchronized with other media objects from an end-user perspective. Results show the presence of two main synchronization regions, and that olfaction ahead of audiovisual content is more tolerable than olfaction behind content

Quality of perception: User quality of service in multimedia presentations

We define quality of perception (QoP) as representing the user side of the more technical and traditional quality of service. QoP encompasses not only a user’s satisfaction with the quality of multimedia presentations, but also his/her ability to analyze, synthesise and assimilate the informational content of multimedia displays.We found that significant reductions in frame rate and color depth does not result in a significant QoP degradation

Synchronization of Olfaction-enhanced multimedia

This paper presents the results of an experimental study carried out to explore, from an end user perspective, the temporal boundaries within which olfactory data can be used to enhance multimedia applications. Results show the presence of two main synchronization regions, and that olfaction ahead of audiovisual content is more tolerable than olfaction behind content

User quality of experience of mulsemedia applications

User Quality of Experience (QoE) is of fundamental importance in multimedia applications and has been extensively studied for decades. However, user QoE in the context of the emerging multiple-sensorial media (mulsemedia) services, which involve different media components than the traditional multimedia applications, have not been comprehensively studied. This article presents the results of subjective tests which have investigated user perception of mulsemedia content. In particular, the impact of intensity of certain mulsemedia components including haptic and airflow on user-perceived experience are studied. Results demonstrate that by making use of mulsemedia the overall user enjoyment levels increased by up to 77%

An Export Architecture for a Multimedia Authoring Environment

In this paper, we propose an export architecture that provides a clear separation of authoring services from publication services. We illustrate this architecture with the LimSee3 authoring tool and several standard publication formats: Timesheets, SMIL, and XHTML

The perceptual and attentive impact of delay and jitter in multimedia delivery

In this paper we present the results of a study that examines the user’s perception—understood as both information assimilation and subjective satisfaction—of multimedia quality, when impacted by varying network-level parameters (delay and jitter). In addition, we integrate eye-tracking assessment to provide a more complete understanding of user perception of multimedia quality. Results show that delay and jitter significantly affect user satisfaction; variation in video eye path when either no single/obvious point of focus exists or when the point of attention changes dramatically. Lastly, results showed that content variation significantly affected user satisfaction, as well as user information assimilation

Self-modifiable color petri nets for modeling user manipulation and network event handling

A Self-Modifiable Color Petri Net (SMCPN) which has multimedia synchronization capability and the ability to model user manipulation and network event (i.e. network congestion, etc.) handling is proposed in this paper. In SMCPN, there are two types of tokens: resource tokens representing resources to be presented and color tokens with two sub-types: one associated with some commands to modify the net mechanism in operation, another associated with a number to decide iteration times. Also introduced is a new type of resource token named reverse token that moves to the opposite direction of arcs. When user manipulation/network event occurs, color tokens associated with the corresponding interrupt handling commands will be injected into places that contain resource tokens. These commands are then executed to handle the user manipulation/network event. SMCPN has the desired general programmability in the following sense: 1) It allows handling of user manipulations or pre-specified events at any time while keeping the Petri net design simple and easy. 2) It allows the user to customize event handling beforehand. This means the system being modeled can handle not only commonly seen user interrupts (e.g. skip, reverse, freeze), the user is free to define new operations including network event handling. 3) It has the power to simulate self-modifying protocols. A simulator has been built to demonstrate the feasibility of SMCPN

Synote: development of a Web-based tool for synchronized annotations

This paper discusses the development of a Web-based media annotation application named Synote, which addresses the important issue that while the whole of a multimedia resource on the Web can be easily bookmarked, searched, linked to and tagged, it is still difficult to search or associate notes or other resources with a certain part of a resource. Synote supports the creation of synchronized notes, bookmarks, tags, links, images and text captions. It is a freely available application that enables any user to make annotations in and search annotations to any fragment of a continuous multimedia resource in the most used browsers and operating systems. In the implementation, Synote categorized different media resources and synchronized them via time line. The presentation of synchronized resources makes full use of Web 2.0 AJAX technology to enrich interoperability for the user experience. Positive evaluation results about the performance, efficiency and effectiveness of Synote were returned when using it with students and teachers for a number of undergraduate courses