Dynamic overlay multicast in 3D video collaborative systems
Proceedings of the 18th international workshop on Network and operating systems support for digital audio and video
MM '09 Proceedings of the 17th ACM international conference on Multimedia
Virtual director technology for social video communication and live event broadcast production
Proceedings of the 21st ACM international conference on Multimedia
| Hi-index | 0.00 |
Recent years witnessed the emergence of more "multi-stream" Multimedia applications, such as multi-site distributed video conferencing, multi-perspective IPTV, and virtual touring of 3D digital worlds from multiple view points, etc.In this work, we study the problem of visual space management in such applications. The key observation is that there are multiple visual streams that need to be presented to the users, while the visual space is limited both by availability of physical display devices and by user's visual attention space. We argue that the visual space is a type of critical resource that requires careful management in similar way as other resources (such as CPU cycles and memory slots). Specifically, the unique challenges are how to model the visual streams and the viewers' preference among them, how to determine which of these visual streams should be presented to the viewer, and how the output windows of these selected streams should be arranged on the display devices.Many existing systems have explored the solution space from different perspectives, but none of them provide a solution that is customized to user interest, automatic to avoid unnecessary user input, and yields high visual quality screen output. In this work, we introduce a 3-phase visual space management framework called MyView that makes the following three key contributions. First, a generic shot-based visual stream model and a score-based viewer interest model are designed to represent user interest, which lays the foundation for automatic visual space management decisions. Second, an automatic stream selection algorithm is developed that maintains a timed automaton to calculate which visual streams should be selected for display. Third, a screen layout calculation algorithm is designed to compute the screen layout for presenting the selected visual stream(s) on one or multiple display devices in a visual pleasing way that maximizes screen space utilization.We have built a lecture recording and broadcasting system on top of the ConferenceXP platform to evaluate our solution. Results from both simulation experiments and user study have confirmed the functional correctness and usability of the MyView framework.