Dick C. A. Bulterman

Video-conferencing is becoming an essential part in everyday life. The visual channel allows for interactions which 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 video-conferencing experience is subject to variations, dependent on network conditions. Video-conferencing systems adapt to network conditions by changing for example encoding bitrate 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 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 4 people collaboratively build a Lego® model over a video-conferencing 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 bitrate 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 which double the accuracy compared to a model based on the system factors alone. We conclude with a discussion how these factors could be applied in real world scenarios.

This chapter reports on the Ambulant Annotator, a middleware extension for Personal Digital Recorders (PDR), in the form of a lightweight authoring tool, which allows the viewer to personalize television content and share it with others. Traditionally, social interactive television research has focused on the provision of synchronous communication mechanisms between distributed peers in the form of direct communication channels (text or audio chats) or distributed control (joint television watching experience). This chapter considers a broader approach that enhances the connectedness between users by providing video sharing capabilities. The Ambulant Annotator empowers viewer-side enrichment of multimedia content in the form of video fragmentation, fragments annotation and enrichment. Once the user has created his personalized enriched version of the video content, the Ambulant Annotator provides mechanisms to share it with his social network by using asynchronous communication technologies. The video manipulation mechanisms presented in this chapter does not modify the original video material, but are encoded as separate overlays in such a way that Digital Rights Management (DRM) restrictions on content reuse are respected.

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.