This paper examines the document aspects of object-based broadcasting. Object-based broadcasting augments traditional video and audio broadcast content with additional (temporally-constrained) media objects. The content of these objects -- as well as their temporal validity -- are determined by the broadcast source, but the actual rendering and placement of these objects can be customized to the needs/constraints of the content viewer(s). The use of object-based broadcasting enables a more tailored end-user experience than the one-size-fits-all of traditional broadcasts: the viewer may be able to selectively turn off overlay graphics (such as statistics) during a sports game, or selectively render them on a secondary device. Object-based broadcasting also holds the potential for supporting presentation adaptivity for accessibility or for device heterogeneity.

Videoconferencing is becoming an essential part in everyday life. The visual channel allows us for interactions that were not possible over audio-only communication systems, such as the telephone. However, being a de-facto over-the-top service, the quality of the delivered videoconferencing experience is subject to variations, depending on network conditions. Videoconferencing systems adapt to network conditions by changing, for example, encoding bit rate of the video. For this adaptation not to hamper the benefits related to the presence of a video channel in the communication, it needs to be optimized according to a measure of the quality of experience (QoE) as perceived by the user. The latter is highly dependent on the ongoing interaction and individual preferences, which have hardly been investigated so far. In this paper, we focus on the impact that video quality has on conversations that revolve around objects that are presented over the video channel. To this end, we conducted an empirical study where groups of four people collaboratively build a Lego model over a videoconferencing system. We examine the requirements for such a task by showing when the interaction, measured by visual and auditory cues, changes depending on the encoding bit rate and loss. We then explore the impact that prior experience with the technology and affective state have on QoE of participants. We use these factors to construct predictive models that double the accuracy compared to a model based on the system factors alone. We conclude with a discussion of how these factors could be applied in real-world scenarios.

Understanding the emotional reactions of audiences to a wide range of content types is an important area of research. In this article, I provide a personal reflection on various approaches to modeling, quantifying and understanding audience behavior based on a broad range of evaluation techniques. Using results from a study of the Heineken Weasel television commercial as a backdrop, I provide an overview of evaluation approaches and their impact in long-term and real-time evaluation. The main contribution is a personal reflection on audience evaluation based on multi-situation affinity with the area.

Most video platforms deliver HD video in high bitrate encoding. Modern video-conferencing systems are capable of handling HD streams, but using multiparty conferencing, average internet connections in the home are on their bandwidth limit. For properly managing the encoding bitrate in videoconferencing, we must know what is the minimum bitrate requirement to provide users an acceptable experience, and what is the bitrate level after which QoE saturates?. Most available subjective studies in this area used rather dated technologies. We report on a multiparty study on video quality with HD resolution. We tested different encoding bitrates (256kbs, 1024kbs and 4096kbs) and packet loss rates (0, 0.5%) in groups of 4 participants with a scenario based on the ITU building blocks task. We discuss the influence of group interaction and individual idiosyncrasies based on different mixed models, and look at covariates engagement and enjoyment as further explanatory factors. We found that 256kbs is still sufficient to provide a fair overall experience, but video quality is noticed to be poor. On the higher bitrate end, most people will not perceive the difference between 1024kbs and 4096kbs, considering in both cases the quality to be close to excellent. Independent on bitrate, packet loss has a small but significant impact, quantifiable in, on average, less than half a point difference on a 5-point ITU scale.

Geometry based 3D Tele-Immersion is a novel emerging media application that involves on the fly reconstructed 3D mesh geometry. To enable real-time communication of such live reconstructed mesh geometry over a bandwidth limited link, fast dynamic geometry compression is needed. However, most tools and methods have been developed for compressing synthetically generated graphics content. These methods achieve good compression rates by exploiting topological and geometric properties that typically do not hold for reconstructed mesh geometry. The live reconstructed dynamic geometry is causal and often non-manifold, open, non-oriented and time-inconsistent. Based on our experience developing a prototype for 3D Teleimmersion based on live reconstructed geometry, we discuss currently available tools. We then present our approach for dynamic compression that better exploits the fact that the 3D geometry is reconstructed and achieve a state of art rate-distortion under stringent real-time constraints.

3-D tele-immersion (3DTI) enables participants in remote locations to share, in real time, an activity. It offers users interactive and immersive experiences, but it challenges current media-streaming solutions. Work in the past has mainly focused on the efficient delivery of image-based 3-D videos and on realistic rendering and reconstruction of geometry-based 3-D objects. The contribution of this paper is a real-time streaming component for 3DTI with dynamic reconstructed geometry. This component includes both a novel fast compression method and a rateless packet protection scheme specifically designed towards the requirements imposed by real time transmission of live-reconstructed mesh geometry. Tests on a large dataset show an encoding speed-up up to ten times at comparable compression ratio and quality, when compared with the high-end MPEG-4 SC3DMC mesh encoders. The implemented rateless code ensures complete packet loss protection of the triangle mesh object and a delivery delay within interactive bounds. Contrary to most linear fountain codes, the designed codec enables real-time progressive decoding allowing partial decoding each time a packet is received. This approach is compared with transmission over TCP in packet loss rates and latencies, typical in managed WAN and MAN networks, and heavily outperforms it in terms of end-to-end delay. The streaming component has been integrated into a larger 3DTI environment that includes state of the art 3-D reconstruction and rendering modules. This resulted in a prototype that can capture, compress transmit, and render triangle mesh geometry in real-time in realistic internet conditions as shown in experiments. Compared with alternative methods, lower interactive end-to-end delay and frame rates over three times higher are achieved.

Watching digital content together and commenting on it is becoming a social habit between friends and family members living apart. It is also becoming an important value-added activity for business video conferencing. In both cases, the video sharing experience can easily be spoiled if synchronization problems arise, since the context of the conversation will not be consistent across locations. In the past, research has treated the distributed synchronization problem as a technical one, mainly focusing on timestamps, frame accuracy, and protocol-dependent control messages. That approach is based on a content agnostic approach which we feel does not adequately address the higher-level constraints of individual conversations.

3D Tele-immersion enables participants in remote locations to share, in real-time, an activity. It offers users natural interactivity and immersive experiences, but it challenges current networking solutions. Work in the past has mainly focused on the efficient delivery of image-based 3D videos and on the realistic rendering and reconstruction of geometry-based 3D objects. The contribution of this paper is a complete media pipeline that allows for geometry-based 3D tele-immersion. Unlike previous approaches, that stream videos or video plus depth estimate, our streaming module can transmit the live-reconstructed 3D representations (triangle meshes). Based on a set of comparative experiments, this paper details the architecture and describes a novel component that can efficiently stream geometry in real-time. This component includes both a novel fast local compression algorithm and a rateless packet protection scheme geared towards the requirements imposed by real-time transmission of live-capture mesh geometry. Tests on a large dataset show an encoding and decoding speed-up of over 10 times at similar compression and quality rates, when compared to the high-end MPEG-4 SC3DMC mesh encoder. The implemented rateless code ensures complete packet loss protection of the triangle mesh object and avoids delay introduced by retransmissions. This approach is compared to a streaming mechanism over TCP and outperforms it at packet loss rates over 2% and/or latencies over 9 ms in terms of end-to-end transmission delay. As reported in this paper, the component has been successfully integrated into a larger tele-immersive environment that includes beyond state of the art 3D reconstruction and rendering modules. This resulted in a prototype that can capture, compress transmit and render triangle mesh geometry in real-time over the internet.

The complexities and physical constraints associated with video transmission make the introduction of video playout delays unavoidable. Tuning systems to reduce delay requires an ability to effectively and easily gather delay metrics on a potentially wide range of systems. In order to support this process, we report on a system called videoLat. VideoLat provides an innovative approach to understand glass-to-glass video delays. This paper provides a series of requirements for obtaining representative delay information, it illustrates how such measurements can provide insights into complex (and often closed) video processing systems, and it describes how user-centric testing can be supported in a more realistic manner. We also survey the present state of the art in video delay measurement. The main contribution of this work is that it provides a measuring framework that could serve as the basis for obtaining representative comparative measurements across a wide range of video processing environments.

Creating compelling multimedia productions is a nontrivial task. This is as true for creating professional content as it is for nonprofessional editors. During the past 20 years, authoring networked content has been a part of the research agenda of the multimedia community. Unfortunately, authoring has been seen as an initial enterprise that occurs before ‘real’ content processing takes place. This limits the options open to authors and to viewers of rich multimedia content for creating and receiving focused, highly personal media presentations. This article reflects on the history of multimedia authoring. We focus on the particular task of supporting socially-aware multimedia , in which the relationships within particular social groups among authors and viewers can be exploited to create highly personal media experiences. We provide an overview of the requirements and characteristics of socially-aware multimedia authoring within the context of exploiting community content. We continue with a short historical perspective on authoring support for these types of situations. We then present an overview of a current system for supporting socially-aware multimedia authoring within the community content. We conclude with a discussion of the issues that we feel can provide a fruitful basis for future multimedia authoring support. We argue that providing support for socially-aware multimedia authoring can have a profound impact on the nature and architecture of the entire multimedia information processing pipeline.

Using high-quality video cameras on mobile devices, it is relatively easy to capture a significant volume of video content for community events such as local concerts or sporting events. A more difficult problem is selecting and sequencing individual media fragments that meet the personal interests of a viewer of such content. In this paper, we consider an infrastructure that supports the just-in-time delivery of personalized content. Based on user profiles and interests, tailored video mash-ups can be created at view-time and then further tailored to user interests via simple end-user interaction. Unlike other mash-up research, our system focuses on client-side compilation based on personal (rather than aggregate) interests. This paper concentrates on a discussion of language and infrastructure issues required to support just-in-time video composition and delivery. Using a high school concert as an example, we provide a set of requirements for dynamic content delivery. We then provide an architecture and infrastructure that meets these requirements. We conclude with a technical and user analysis of the just-in-time personalized video approach.

Low-cost video conferencing systems have provided an existence proof for the value of video communication in a home setting. At the same time, current systems have a number of fundamental limitations that inhibit more general social interactions among multiple groups of participants. In our work, we describe the development, implementation and evaluation of a domestic video conferencing system that is geared to providing true 'togetherness' among conference participants. We show that such interactions require sophisticated support for high-quality audiovisual presentation, and processing support for person identification and localisation. In this paper, we describe user requirements for effective interpersonal interaction. We then report on a system that implements these requirements. We conclude with a systems and user evaluation of this work. We present results that show that participants in a video conference can be made feel as 'together' as collocated players of a board game.

The evolution in media support within W3C standards has led to the development of HMTL5. HTML5 provides extensive support for audio/video/timed-text within an interoperable browser context.

This panel extends current efforts from the ACM Multimedia 2011 Organization Committee in taking an important step towards open source projects. The panelists include speakers who are among the leading figures from the open source community. The goal is to provide a shared space for discussion and interaction among consolidated and new open source projects and multimedia researchers.

The wide availability of relatively high-quality cameras makes it easy for many users to capture video fragments of social events such as concerts, sports events or community gatherings. The wide availability of simple sharing tools makes it nearly as easy to upload individual fragments to on-line video sites. Current work on video mashups focuses on the creation of a video summary based on the characteristics of individual media fragments, but it fails to address the interpersonal relationships and time-variant social context within a community of diverse (but related) users. The aim of this paper is to reformulate the research problem of video authoring, by investigating the social relationships of the media 'authors' relative to the performers. Based on a 10-month evaluation process, we specify a set of guidelines for the design and implementation of socially-aware video editing and sharing tools. Our contributions have been realized and evaluated in a prototype software that enables community-based users to navigate through a large common content space and to generate highly personalized video compilations of targeted interest within a social circle. According to the results, a system like ours is a valid alternative for social interactions when apart. We hope that our insights can stimulate future research on socially-aware multimedia tools and applications.

In typical video mash-up systems, a group of source videos are compiled off-line into a single composite object. This improves rendering performance, but limits the possibilities for dynamic composition of personalized content. This paper discusses systems and network issues for enabling client-side dynamic composition of video mash-ups. In particular, this paper describes a novel algorithm to support accurate, low-delay seamless composition of independent clips. We report on an intelligent application-steered scheme that allows system layers to prefetch and discard predicted frames before the rendering moment of indexed content. This approach unifies application-level quality-of-experience specification with system layer quality-of-service processing. To evaluate our scheme, several experiments are conducted and substantial performance improvements are observed in terms of accuracy and low delay.

This paper describes a videoconferencing system that meets performance constraints and functional requirements for use in consumer homes. Our system improves existing home technologies (such as video chat) by providing high-quality audiovisual communication, efficient encoding mechanisms, and low end-to-end delay. Moreover, the system includes a control interface that is capable of dynamically manipulating and compositing audiovisual content streams. This innovative architectural component is required for a domestic setting, where the television acts as the main screen and multiple people gather around it. Apart from the requirements and architecture, this paper analyses the performance of our system. The results validate our architectural decisions and provide a valuable input for further research in domestic videoconferencing.

This paper introduces a multimedia document model that can structure community comments about media. In particular, we describe a set of temporal transformations for multimedia documents that allow end-users to create and share personalized timed-text comments on third party videos. The benefit over current approaches lays in the usage of a rich captioning format that is not embedded into a specific video encoding format. Using as example a Web-based video annotation tool, this paper describes the possibility of merging video clips from different video providers into a logical unit to be captioned, and tailoring the annotations to specific friends or family members. In addition, the described transformations allow for selective viewing and navigation through temporal links, based on end-users' comments. We also report on a predictive timing model for synchronizing unstructured comments with specific events within a video(s). The contributions described in this paper bring significant implications to be considered in the analysis of rich media social networking sites and the design of next generation video annotation tools.

Inclusion of content with temporal behavior in a structured document leads to such a document gaining temporal semantics. If we then allow changes to the document during its presentation, this brings with it a number of fundamental issues that are related to those temporal semantics. In this paper we study modifications of active multimedia documents and the implications of those modifications for temporal consistency. Such modifications are becoming increasingly important as multimedia documents move from being primarily a standalone presentation format to being a building block in a larger application.

This paper presents Eureka: a generic methodology of measuring the instantaneous (per second) bandwidth usage of networked games and applications in run time. Eureka starts with constructing a priority queue and sending low priority traffic through it. Then, the application under study is started with its packets marked as high priority. These packets therefore displace the previously existing low priority packets on the priority queue. We can measure this displacement and thus, the bandwidth used by the application. Unlike tcpdump this can be done while the application is running and without knowing any application specific data. In this paper we use Eureka to study the bandwidth usage of Massive Multiplayer Online Games (MMOGs), BZFlag and World of Warcraft-Trial, along with the 3D multi-site collaborative environments. A major strength of our methodology is that it provides run-time estimations of the bandwidth usage without interfering with the application, the environment, or the server/peer data. Moreover, Eureka is independent of the application and new infrastructure or tools are not required.

This paper discusses the architectural challenges of transitioning from services to experiences. In particular, it focuses on evolution from traditional IPTV services to more social scenarios, in which groups of people in different locations watch synchronized multimedia content together. In addition to the multimedia content, the shared experiences envisioned in this article provide a real-time communication channel between the participants. Based on an implemented architecture, this paper identifies a number of challenges and analyze them. The most important challenges highlighted in this article include: shared experience modeling, universal session handling, synchronization, and quality of service. This article is the first stone paving the way for a truly interoperable ecosystem, which can offer cross-domain experiences to the users.

The objective of this work is to define a document model extension that enables complex spatial and temporal interactions within multimedia documents. As an example we describe an authoring interface of a photo sharing system that can be used to capture stories in an open, declarative format. The document model extension defines visual transformations for synchronized navigation driven by dynamic associated content. Due to the open declarative format, the presentation content can be targeted to individuals, while maintaining the underlying data model. The impact of this work is reflected in its recent standardization in the W3C SMIL language. Multimedia players, as Ambulant and the RealPlayer, support the extension described in this paper.

This paper presents a new scheduling algorithm for real time network delivery of packets over Diffserv networks for delay sensitive applications. We name the networks that support this algorithm as Estimated Service (Estserv) networks. These networks, for real time packets, estimate the probability of the packet meeting its deadline and schedule it according to this estimation. This paper validates, given this estimation mechanism, the better performance of the scheduling algorithm over traditional solutions. We show that using Estserv for delay sensitive applications, we can provide out-of-band scheduling, save bandwidth on packets with expired deadlines and handle bursts without loosing the scalability of Diffserv. We show with the help of an implementation in the Linux kernel's ip-forwarding part, that, given the estimation value, Estserv performs better than Diffserv in terms of deadlines, while still saving bandwidth.

Document engineering is the computer science discipline that investigates systems for documents in any form and in all media. As with the relationship between software engineering and software, document engineering is concerned with principles, tools and processes that improve our ability to create, manage, and maintain documents ( http://www.documentengineering.org ). The ACM Symposium on Document Engineering is an annual meeting of researchers active in document engineering: it is sponsored by ACM by means of the ACM SIGWEB Special Interest Group. In this editorial, we first point to work carried out in the context of document engineering, which are directly related to multimedia tools and applications. We conclude with a summary of the papers presented in this special issue.

The migration of media consumption to personal computers retains distributed social viewing, but only via nonsocial, strictly personal interfaces. This article presents an architecture, and implementation for media sharing that allows for enhanced social interactions among users. Using a mixed-device model, our work allows targeted, personalized enrichment of content. All recipients see common content, while differentiated content is delivered to individuals via their personal secondary screens. We describe the goals, architecture, and implementation of our system in this article. In order to validate our results, we also present results from two user studies involving disjoint sets of test participants.

This working session will be an interactive discussion about multimedia content transformation. The basic assumption is that content transformation activities should be provided as non-destructive operations. The final goal of the panel is to gather researchers within the community interested in manipulating multimedia content for providing rich user experiences. The organizers of the panel will moderate and shape the discussion; nevertheless, position papers from the participants are expected.

This paper demonstrates the advantages of using structured multimedia documents for session management and media distribution in ubiquitous environments. We show how document manipulations can be used to perform powerful operations such as content to context adaptation and presentation continuity. When consuming media in ubiquitous environments, where the set of devices surrounding a user may change, dynamic media adaptation and session transfer become primary requirements. This paper presents a working system, based on a representative scenario, in which multimedia content is distributed and adapted to a movable user to best suit his/her contextual situation. The implemented scenario includes the following scenes: content selection using a personal mobile phone, content distribution to the most suitable device according to the user's context, and presentation continuity when the user moves to another location. This paper introduces the underlying document manipulations that turn the scenario into a working system.

In this paper we examine adaptive time-based web applications (or presentations). These are interactive presentations where time dictates the major structure, and that require interactivity and other dynamic adaptation. We investigate the current technologies available to create such presentations and their shortcomings, and suggest a mechanism for addressing these shortcomings. This mechanism, SMIL State, can be used to add user-defined state to declarative time-based languages such as SMIL or SVG animation, thereby enabling the author to create control flows that are difficult to realize within the temporal containment model of the host languages. In addition, SMIL State can be used as a bridging mechanism between languages, enabling easy integration of external components into the web application.

Media consumption is an inherently social activity, serving to communicate ideas and emotions across both small- and large-scale communities. The migration of the media experience to personal computers retains social viewing, but typically only via a non-social, strictly personal interface. This paper presents an architecture and implementation for media content selection, content (re)organization, and content sharing within a user community that is heterogeneous in terms of both participants and devices. In addition, our application allows the user to enrich the content as a differentiated personalization activity targeted to his/her peer-group. We describe the goals, architecture and implementation of our system in this paper. In order to validate our results, we also present results from two user studies involving disjoint sets of test participants.

This paper presents an approach for media presentation continuity in playback mode. We use the term presentation continuity over session transfer since our solution is at the presentation layer. Previous research on this topic has focused on transferring a particular stream or set of related streams at the sessions layer for live broadcasting or conferencing sessions. We argue that in the realm of service oriented architectures, such as telecom operator networks, this approach does not take full advantage of the particular case of media playback. Our mechanism presents an alternative to the traditional approach, which i) Lowers network control plane overhead, thus reducing chances of presentation consistency loss ii) Lowers network data overhead due to lesser need for transcoding iii) Delegates presentation consistency issues, such as inter-media synchronisation, to the media player iv) Dynamically adapts the presentation to the new target devices without transcoding. Finally, we present experimental results which show that our approach is implementable in acceptable time bounds.

This demo presents a new approach for media presentation continuity in playback mode. We use the term presentation continuity over session transfer since our solution is at the presentation layer. Previous research on this topic has focused on transferring a particular stream or set of related streams at the sessions layer. Our approach presents an alternative, recognising the fact that a user is connected to a media presentation, which, may be composed of multiple sessions. The advantages of our approach are i) Lower network control plane overhead, thus reducing chances of semantic presentation loss ii) Lower network data overhead due to lesser need for transcoding iii) delegating presentation semantic issues, such as inter-media synchronisation, to the player iv) dynamically adapt the presentation to the new target devices without transcoding.

The research area of interactive digital TV is in the midst of a significant revival. Unlike the first generation of digital TV, which focused on producer concerns that effectively limited (re)distribution, the current generation of research is closely linked to the role of the user in selecting, producing, and distributing content. The research field of interactive digital television is being transformed into a study of human-centered television. Our guest editorial reviews relevant aspects of this transformation in the three main stages of the content lifecycle: content production, content delivery, and content consumption. While past research on content production tools focused on full-fledged authoring tools for professional editors, current research studies lightweight, often informal end-user authoring systems. In terms of content delivery, user-oriented infrastructures such as peer-to-peer are being seen as alternatives to more traditional broadcast solutions. Moreover, end-user interaction is no longer limited to content selection, but now facilitates nonlinear participatory television productions. Finally, user-to-user communication technologies have allowed television to become a central component of an interconnected social experience. The background context given in this article provides a framework for appreciating the significance of four detailed contributions that highlight important directions in transforming interactive television research.

In spite of the high profile of media types such as video, audio and images, many multimedia presentations rely extensively on text content. Text can be used for incidental labels, or as subtitles or captions that accompany other media objects. In a multimedia document, text content is not only constrained by the need to support presentation styles and layout, it is also constrained by the temporal context of the presentation. This involves intra-text and extra text timing synchronization with other media objects. This paper describes a new timed-text representation language that is intended to be embedded in a non-text host language. Our format, which we call aText (for the Ambulant Text Format), balances the need for text styling with the requirement for an efficient representation that can be easily parsed and scheduled at runtime. aText, which can also be streamed, is defined as an embeddable text format for use within declarative XML languages. The paper presents a discussion of the requirements for the format, a description of the format and a comparison with other existing and emerging text formats. We also provide examples for aText when embedded within the SMIL and MLIF languages and discuss our implementation experiences of aText with the Ambulant Player.

This paper presents a system that exploits the benefits of modelling multimedia presentations as structured documents within the context of interactive digital television systems. Our work permits end-users to easily enrich multimedia content at viewing time (e.g., add images and delete scenes). Because the document is structured, the system can expose to the user the possible enrichment alternatives depending on the current state of the presentation (e.g., current story). Moreover, because the base content is wrapped as a structured document, the enrichments can be modelled as overlying layers that do not alter the original content. Finally, the user can share the enriched content (or parts of it) to specific peers within a P2P network.

This paper presents a set of demos that allow viewer-side enrichment of multimedia content in a home setting. The most relevant features of our system are the following: passive authoring of content in contraposition to the traditional active PC authoring, preservation of the base content, and collaborative authoring (e.g., to share the enriched material with a peer group). These requirements are met by modelling television content as structured multimedia documents using SMIL 2.1.

This paper presents a user interface model and implementation for exploiting next-generation interactive capabilities with the domain of television content. Our work studies capabilities that extend a user's potential impact over the consumption and sharing of television programs. The main capabilities of our environment include personalized viewing and navigation within a program fragment, and the ability to actively personalize content via various end-user content enrichments (such as line art, referrals and hyperlink insertions). In this paper, we present the implementation of a range of "couch-top" control and editing devices, including personal devices such as personal digital assistants and ad-hoc interactive devices. This paper also presents an architecture that decouples user actions into activators and handlers. We provide an overview of the interaction architecture and report on a series of deployment experiments on a wide range of consumer electronics devices.

Much of the work in engineering complex documents has been on building a path from a document model (or document abstraction) to one or more instances of that document during a publication phase. While many approaches exist to help create multiple instances from a single document, all of these instances share the property that the content (once created) is fixed.In this talk, we consider more flexible bindings of information packaging and publication. The main goal of this work is to allow a large degree of uncertainty to document content -- uncertainty that is motivated by incremental authoring processes (where the contents of a document are enriched over its lifetime), uncertainty that is motivated by continuous adaptation of content based on changes in the nature and architecture of the underlying rendering environment, and uncertainty that is motivated by temporal navigation through various set of interwoven, conditionally-active content layers.Several use cases will be discussed (including entertainment, accessible documents and medical applications) and a flexible, non-monolithic document reader/annotator architecture will be shown based on the Ambulant renderer.

Authoring context sensitive, interactive multimedia presentations is much more complex than authoring either purely audiovisual applications or text. Interactions among media objects need to be described as a set of spatio-temporal relationships that account for synchronous and asynchronous interactions, as well as on-demand linking behavior. This article considers the issues that need to be addressed by an authoring environment. We begin with a partitioning of concerns based on seven classes of authoring problems. We then describe a selection of multimedia authoring environments within four different authoring paradigms: structured, timeline, graph and scripting. We next provide observations and insights into the authoring process and argue that the structured paradigm provides the most useful framework for presentation authoring. We close with an example application of the structured multimedia authoring paradigm in the context of our own structure-based system GRiNS.

No abstract available.

This paper provides an overview of the Ambulant Open SMIL player. Unlike other SMIL implementations, the Ambulant Player is a reconfigureable SMIL engine that can be customized for use as an experimental media player core. The Ambulant Player is a reference SMIL engine that can be integrated in a wide variety of media player projects. This paper starts with an overview of our motivations for creating a new SMIL engine, then discusses the architecture of the Ambulant Core (including the scalability and custom integration features of the player). We close with a discussion of our implementation experiences with Ambulant instances for Windows, Mac and Linux versions for desktop and PDA devices.

This paper discusses applying facilities in SMIL 2.0 to the problem of annotating multimedia presentations. Rather than viewing annotations as collections of (abstract) meta-informa-tion for use in indexing, retrieval or semantic processing, we view annotations as a set of peer-level content with temporal and spatial relationships that are important in presenting a coherent story to a user. The composite nature of the collection of media is essential to the nature of peer-level annotations: you would typically annotate a single media item much differently than that same media item in the context of a total presentation.This paper focuses on the document engineering aspects of the annotation system. We do not consider any particular user interface for creating the annotations or any back-end storage architecture to save/search the annotations. Instead, we focus on how annotations can be represented within a common document architecture and we consider means of providing docu-ment facilities that meet the requirements of our user model. We present our work in the context of a medical patient dossier example.

The title of the panel implies a walk through on different interfaces based on human-dependent assumptions that may condition their implementation, their application and their usability. The nature of the problems encountered when designing a system that should be used by different classes of users - and therfore must satisfy and facilitate access to information to people having varied skills - is manifold. Nevertheless, by designing user-centered interfaces we are trying to improve the quality of work, reduce memory load, enable the detection and extraction of the required information for making evaluations, taking decisions and smoothly progress along a well-defined path until the project termination.The people in the panel have a wide range of experiences in the broad area of multimedia communication and, more particularly, have worked in different communication domains where the spatial view, the environment and the application determine the features of the interface, in some cases considering management and inventory problems, artistic work, data search and navigation activities, in others restoration (and relative documentation) projects with the possibility of monitoring such projects. In particular, the importance of a small scale prototype to verify some of the basic assumptions, which were established at the beginning of the interface design project, must be strongly considered. The purpose of the panel will be to review and discuss the nature of communication for a given set of environments and cultural patterns, debating the nature of some established guidelines and suggesting new ones while also focusing on the specific applications stemming from Cultural Heritage, where the nature of information is complex and multifold: numerical, textual and pictorial. Likewise, the motivation for the users of the proposed systems may differ from one time period to another, so changing goals, methods and actions to be undertaken by such users according to the present status of the activity. Restoration, classification, documentation and presentation are some of the different functions that are typical of the application we are considering and which will be analyzed by the panelists.

This paper describes document modelling constructs that support alternate content choices for generalized hypermedia presentations.While there has been much work done on adaptive hypermedia documents in the context of low-level quality-of-service adaptation, little attention has been paid to support of user-level adaptation of multimedia content.Taking examples from the domains of information accessibility for the visual/hearing impaired, multilingual information presentation, and content adaptation in distance learning, we show how simple interfaces to rich hypermedia documents can give decided benefits to the user community.We discuss our work in terms of experiments from the CWI CMIF project and indicate how these solutions have been integrated with the W3C SMIL language in the GRiNS editor and player for Web use. 1.

ACM Copyright Notice In order to facilitate adaptability of hypermedia documents a distinction is often made between the underlying conceptual structure of a document and the structure of its presentation. This distinction enables greater variety in how a presentation can be adapted to best convey these underlying concepts in a given situation. What is often confusing for those applying this distinction is that although both levels of structure often share similar components: transformation form the storage of a document to its presentation sometimes occurs directly between these similar components and sometimes does not. These similarities typically fall in the categories of space, time and relationships between document portions. This paper identifies some primary similarities between the structure of hypermedia storage and presentation. It also explores how the transformation from storage to presentation often does not follow these similarities. This discussion is illustrated with the Fiets hypermedia application, which addresses the issues of storage, presentation and transformation using public domain formats and tools. The intention is to

This paper discusses the implementation of adaptability in environments that are based on the standard reference model for intelligent multimedia presentation systems. This adaptability is explored in the context of style sheets, which are represented in such formats as DSSSL. The use of existing public standards and tools for this implementation of style sheet-based adaptability is described. The Berlage environment is presented, which integrates these standards and tools into a complete storage-to-presentation hypermedia environment. The integration of the SRM into the Berlage environment is introduced in this work. This integration illustrates the issues involved in implementing adaptability in the model.

Being able to author a hypermedia document once for presentation under a wide variety of potential circumstances requires that it be stored in a manner that is adaptable to these circumstances.Since the nature of these circumstances is not always known at authoring time, specifying how a document adapts to them must be a process that can be performed separately from its original authoring.These distinctions include the porting of the document to different platforms and formats and the adapting of the document's presentation to suit the needs of the user and of the current state of the presentation environment.In this paper we discuss extensions to our CMIF hypermedia authoring and presentation environment that provide adaptability through this distinction between authoring and presentation specification.This extension includes the use of HyTime for document representation and of DSSSL for presentation specification.We also discuss the Berlage architecture, our extension to HyTime that specifies the encoding of certain hypermedia concepts useful for presentation specification.

As the availability of digital video becomes commonplace, a shift in application focus will occur from merely accessing video as an independent data stream to embedding video with other multimedia data types into coordinated hypermedia presentations. The migration to embedded video will present new demands on application and support environments: processing of any one piece of video data will depend on how that data relates to other data streams active within the same presentation. This article describes presentation, synchronization, and interaction control issues for manipulating embedded video. First we describe the requirements for embedded video, contrasted against other forms of video use. Next we consider mechanisms for describing and implementing the behavior of embedded-video segments relative to other data items in a document; these relationships form the basis of implementing cooperative control among the events in a presentation. Finally we consider extending the possibilities for tailoring embedded video to the characteristics of the local runtime environment; this forms the basis for adaptive, application-level quality-of-service control of a presentation. In all cases, we describe a mechanism to externalize the behavior of hypermedia presentations containing resource-intensive data requirements so that effective control can be implemented by low-level system facilities based on application-specific requirements. We present our results in terms of the CMIFed authoring/presentation system.

We present the user interface to the CMIF authoring environment for constructing and playing multimedia presentations.The CMIF authoring environment supports a rich hypermedia document model allowing structure-based composition of multimedia presentations and the specification of synchronization constraints between constituent media items.An author constructs a multimedia presentation in terms of its structure and additional synchronization constraints, from which the CMIF player derives the precise timing information for the presentation.We discuss the advantages of a structured approach to authoring multimedia, and describe the facilities in the CMIF authoring environment for supporting this approach.The authoring environment presents three main views of a multimedia presentation: the hierarchy view is used for manipulating and viewing a presentation's hierarchical structure; the channel view is used for managing logical resources and specifying and viewing precise timing constraints; and the player for playing the presentation.We present the authoring environment in terms of a short example: constructing a walking tour of Amsterdam.

Article CMIFed: a presentation environment for portable hypermedia documents Share on Authors: Guido van Rossum View Profile , Jack Jansen View Profile , K. Sjoerd Mullender View Profile , Dick C. A. Bulterman View Profile Authors Info & Claims MULTIMEDIA '93: Proceedings of the first ACM international conference on MultimediaSeptember 1993 Pages 183–188https://doi.org/10.1145/166266.166287Published:01 September 1993 58citation550DownloadsMetricsTotal Citations58Total Downloads550Last 12 Months19Last 6 weeks1 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteGet Access

One use of integrated System-level Design Automation (SLDA) tools is during the development of algorithm-driven architectures. In this paper, we discuss an approach to structuring SLDA tools that provides application-area designers a flexible range of support for migrating algorithms into special-purpose computer networks. Using digital signal processing applications as an example problem domain, we discuss the motivation and current implementation of a set of design migration tools used to develop real-time distributed architectures as part of the Brown Computer-Aided System Engineering (CASE) project.