A General Framework and Communication Protocol for the Real-Time Transmission of Interactive Media

In this paper we present a general framework for the real-time transmission ofinteractive media, i.e. media involving user interaction. Examples of interactive media are shared whiteboards, Java animations and VRML worlds. By identifying and supporting the common aspects of this media class the framework allows the development of generic services for network sessions involving the transmission of interactive media. Examples are mechanisms for late join and session recording. The proposed framework is based on the Real-Time Transport Protocol (RTP) which is widely used in the Internet for the real-time transmission of audio and video. Using the experience gained through the framework for audio and video, our work consists of three important parts: the definition of a protocol profile, the instantiation of this profile for specific media, and the development of generic services. The profile captures those aspects that are common to the class of interactive media. A single medium must instantiate this profile by providing media-specific information in the form of a payload type definition. Based on the profile, generic services can be developed for all interactive media. In this paper we focus on the description of the profile for the real-time transmission of interactive media. We then present the main ideas behind a generic recording service. Finally we show how multi-user VRML and distributed interactive Java animations can instantiate the profile

Service Platform for Converged Interactive Broadband Broadcast and Cellular Wireless

A converged broadcast and telecommunication service platform is presented that is able to create, deliver, and manage interactive, multimedia content and services for consumption on three different terminal types. The motivations of service providers for designing converged interactive multimedia services, which are crafted for their individual requirements, are investigated. The overall design of the system is presented with particular emphasis placed on the operational features of each of the sub-systems, the flows of media and metadata through the sub-systems and the formats and protocols required for inter-communication between them. The key features of tools required for creating converged interactive multimedia content for a range of different end-user terminal types are examined. Finally possible enhancements to this system are discussed. This study is of particular interest to those organizations currently conducting trials and commercial launches of DVB-H services because it provides them with an insight of the various additional functions required in the service provisioning platforms to provide fully interactive services to a range of different mobile terminal types

Semi-automated creation of converged iTV services: From macromedia director simulations to services ready for broadcast

While sound and video may capture viewers’ attention, interaction can captivate them. This has not been available prior to the advent of Digital Television. In fact, what lies at the heart of the Digital Television revolution is this new type of interactive content, offered in the form of interactive Television (iTV) services. On top of that, the new world of converged networks has created a demand for a new type of converged services on a range of mobile terminals (Tablet PCs, PDAs and mobile phones). This paper aims at presenting a new approach to service creation that allows for the semi-automatic translation of simulations and rapid prototypes created in the accessible desktop multimedia authoring package Macromedia Director into services ready for broadcast. This is achieved by a series of tools that de-skill and speed-up the process of creating digital TV user interfaces (UI) and applications for mobile terminals. The benefits of rapid prototyping are essential for the production of these new types of services, and are therefore discussed in the first section of this paper. In the following sections, an overview of the operation of content, service, creation and management sub-systems is presented, which illustrates why these tools compose an important and integral part of a system responsible of creating, delivering and managing converged broadcast and telecommunications services. The next section examines a number of metadata languages candidates for describing the iTV services user interface and the schema language adopted in this project. A detailed description of the operation of the two tools is provided to offer an insight of how they can be used to de-skill and speed-up the process of creating digital TV user interfaces and applications for mobile terminals. Finally, representative broadcast oriented and telecommunication oriented converged service components are also introduced, demonstrating how these tools have been used to generate different types of services

Rapid prototyping and fast user trial of multimedia broadcast and cellular services

This paper presents the results of fast user trial of multimedia services that are enabled when a mobile terminal has access to converged services over digital broadcast and mobile telecommunications networks. It first describes the motivations behind developing this system and describes the service scenarios that benefit most from it. It then provides an overview of the service components of the test case scenario. Finally, it presents the results of fast user trials on end users of the services that were developed. This work was conducted as part of the EU-funded CISMUNDUS project

Transforming Multimedia Structural Information into Semantics

In this paper a new approach to metadata production is presented. For this purpose, a new interactive tool for audiovisual content acquisition and classication has been developed. The user can decompose a given content into units and easily annotate each unit adding basic information such as time, place, etc. as well classication information such as event type, relationship type, etc. according to the MPEG 7 Standard. At the end of this production process, the tool automatically produces a structural description of the overall set of the annotated units. The new idea proposed in this work is to combine the intrinsic semantics of each annotated unit with the implicit semantic information derived from the structural description, hence reducing the needs to perform complex signal processing operations on the content. This aspect is really important since image and video processing is generally heavier than metadata processing and the content can be spread over a network and not made readily available at the processing point

Semantic multimedia remote display for mobile thin clients

Current remote display technologies for mobile thin clients convert practically all types of graphical content into sequences of images rendered by the client. Consequently, important information concerning the content semantics is lost. The present paper goes beyond this bottleneck by developing a semantic multimedia remote display. The principle consists of representing the graphical content as a real-time interactive multimedia scene graph. The underlying architecture features novel components for scene-graph creation and management, as well as for user interactivity handling. The experimental setup considers the Linux X windows system and BiFS/LASeR multimedia scene technologies on the server and client sides, respectively. The implemented solution was benchmarked against currently deployed solutions (VNC and Microsoft-RDP), by considering text editing and WWW browsing applications. The quantitative assessments demonstrate: (1) visual quality expressed by seven objective metrics, e.g., PSNR values between 30 and 42 dB or SSIM values larger than 0.9999; (2) downlink bandwidth gain factors ranging from 2 to 60; (3) real-time user event management expressed by network round-trip time reduction by factors of 4-6 and by uplink bandwidth gain factors from 3 to 10; (4) feasible CPU activity, larger than in the RDP case but reduced by a factor of 1.5 with respect to the VNC-HEXTILE

A two-way interactive broadband satellite architecture to break the digital divide barrier

September 24-26, 2007, Turin, Ital