Synchronization and storage models for multimedia objects

Abstract

Multimedia computer systems are required to store, retrieve, and communicate objects comprised of mixed data types including images, text and voice. An important aspect of multimedia systems is the integration of elements retrieved from databases distributed across a network. Integration of object components requires consideration of the temporal characteristics of multimedia elements. We propose a technique for the formal specification and modeling of multimedia composition with respect to intermedia timing. The proposed model is based on the logic of temporal intervals, and Timed Petri Nets. A strategy is evinced for constructing a database schema to facilitate data storage and retrieval of media elements based on the temporal relationships established by the proposed modeling tool. We present an algorithm which allows the retrieval of media elements from the constructed database in a manner which preserves the temporal requirements of the initial specification. Through the proposed model, the synchronization requirements of complex structures of temporally related objects can be easily specified.

Logical Mapping: An Intermedia Synchronization Model for Multimedia Distributed Systems

“…The offline mode refers to when the specification of a temporal scenario is manually made, and it preceds the media data transmision. The most representative works in this category are: the object composition Petri net model (OCPN) introduced by Little and Gafford [7], the timing and synchronization model of SMIL [2], and the time ontology model of OWL [4]. The main characteristic of the works in this category is that they require complete previous knowledge of the media data, the temporal dependencies and/or the order of actions before carrying out the temporal specification.…”

A Hierarchical Petri Net Model for SMIL Documents

“…Petri Net-based models provide a good method to specify temporal relationships (Ramchandani, 1974). A modified Petri Net model, object composition Petri Net (OCPN) (Little et al, 1990), has been proved to have the ability to specify any arbitrary temporal relationship among media elements. However, when dealing with the real time issues and the complex synchronization constraints of SMIL, this model is not powerful enough to capture all the timing and synchronization semantics of SMIL documents.…”

Adaptive Scheduling of Multimedia Documents

“…Multiple variations of Petri Net models such as OCPN [6] or TSPN [10] exist which have a strong expressive power according to the specification of synchronization aspects. However, these models do not adapt documents with regard to the resource situation.…”