2005 Reports

P2P Video Synchronization in a Collaborative Virtual Environment

Gupta, Suhit; Kaiser, Gail E.

We have previously developed a collaborative virtual environment (CVE) for small-group virtual classrooms, intended for distance learning by geographically dispersed students. The CVE employs a peer-to-peer approach to the frequent real-time updates to the 3D virtual worlds required by avatar movements (fellow students in the same room are depicted by avatars). This paper focuses on our extension to the P2P model to support group viewing of lecture videos, called VECTORS, for Video Enhanced Collaboration for Team Oriented Remote Synchronization. VECTORS supports synchronized viewing of lecture videos, so the students all see 'the same thing at the same time', and can pause, rewind, etc. in synchrony while discussing the lecture material via 'chat'. We are particularly concerned with the needs of the technologically disenfranchised, e.g., whose only Web/Internet access if via dialup or other relatively low-bandwidth networking. Thus VECTORS employs semantically compressed videos with meager bandwidth requirements. Further, the videos are displayed as a sequence of JPEGs on the walls of a 3D virtual room, requiring fewer local multimedia resources than full motion MPEGs.