Towards ubiquitous distributed multimedia: UPnP-based control and scripting

One of the most important enablers when assembling a modern ubiquitous computing system is distribution of multimedia content throughout a home and control of its playback. Additionally, ambient intelligence requirements include playback timeline programming, interaction with sensors and event-based playback triggering. Normally there is a central server dedicated to content storage and streaming to one or more spatially displaced viewing screens. In this paper we present a newly developed portable software library that provides mechanisms to control multimedia distribution and playback from one or more content servers, to multiple screens. The control is based on UPnP/DLNA protocol stack, therefore supporting integration of many off-the-shelf UPnP/DLNA compatible multimedia servers or playback devices. The primary goal is to interpret custom scripts written to achieve desired multimedia ambient. These scripts provide control over content distribution and playback based on time triggers and external, arbitrary events, such as sensor readings and user commands. The library provides faster response to a control command in comparison to traditional UPnP control points. Content providers and their physical addresses are hidden from users enforcing the concept of a media “cloud” to fetch the content from. Content can also be distributed to multiple targets at once, whereas it retains control synchronization.