Context-aware adaptation of multimedia documents for consistent presentations
We propose in this paper a context-aware adaptation technique for SMIL encoded multimedia documents. Our approach is mainly dedicated to run in compile-time but we discuss also how it can be used in runtime. Our algorithm aims at improving the execution of a multimedia presentation. This is achieved by scheduling object pre-fetchings in the presentation while monitoring bandwidth and memory space availabilities. For this effect, a request pattern computed from the temporal graph of the SMIL specification is exploited in order to apply an optimal policy to select which objects should be pre-fetched, real time delivered or discarded, even. The algorithm can be used as a tool to evaluate and to monitor the QoS of a presentation. At compile time, it makes it possible to assess whether the QoS of a presentation can be guaranteed after enforcing specific context-oriented adaptations. At authoring stage, this algorithm can be used, for instance, to produce different alternative sub-codes, such that each one is adapted to run in a specific context. In runtime, the algorithm can provide a mechanism to monitor the elastic time computation in case of a mismatch occurrence. In order to advocate our proposal, some experimentation results performed on a simulation platform are reported.
consistency smil multimedia presentation scheduling bandwidth memory qos prefetching compile time adaptation