H-SMIL-Net: A Hierarchical Petri Net Model for SMIL Documents

Abstract

We propose in this paper a hierarchical and temporal extension of Petri Nets for the incremental authoring of SMIL multimedia documents. The complexity of these documents can lead authors, in some cases, to specify synchronization relations which could not be satisfied during the presentation of the document, what characterizes the occurrence of inconsistencies; a consistency checking mechanism is then necessary. This new model, named H-SMIL-Net (Hierarchical SMIL-Petri Net) proposes a technique for the incremental verification of temporal consistency. The originality of the solution resides in the modular aspect of the modelling, and the local approach of verification, what optimizes the verification time after each editing operation. This formal approach has been integrated in an incremental authoring tool for SMIL presentations.

Automatic Multimedia Creation Enriched with Dynamic Conceptual Data

“…There are several authoring tools for developing multimedia presentations in SMIL. Some of the research solutions like H-SMIL-Net [8], LimSee2 [9] and SMILAuthor2 [10] provide SMIL authoring interface for multimedia objects. They are designed to interpret the temporal behavior of a multimedia presentation, associate hyperlinks with media objects, enable interactivity, and describe the layout of the presentation on a screen.…”

Analysis and verification of SMIL documents

“…Moreover, the approach suffers from the explosion problem: the computation time increases exponentially with the document size. More recently, Bouyakoub et al [2,5] treat also some spatial elements (the area element) with Petri Nets. Despite the implementation of an authoring tool for correct SMIL documents, the set of behaviors that can be produced is still limited, since they do not consider significant SMIL features, like the excl element.…”

“…2.1, non-interactive events are recorded differently in the state of the player, since they are not traced by the function r s but by function r d . As an example, consider the elements in case (1), the whole par statement ends when media item au ends; in case (2) media item m begins 5 s after the beginning of n. Table 9 Proof rule for multiple executions of the same element 5 We consider only positive offsets since the rule deals only with interactive events. 6 We suppose that the attribute restart assumes the default value always.…”

A Hierarchical Petri Net Model for SMIL Documents

“…So, we have proposed a hierarchical extension of the SMIL-Net model for the incremental and structured edition. The enhanced model, named H-SMIL-Net (Bouyakoub & Belkhir, 2008), offers structured modelling possibilities permitting, on the one hand, to facilitate the modifications and on the other hand to support an incremental specification of the document. The model is mapped on the SMIL hierarchical temporal structure to better fit with the modelling needs of this language.…”

“…Yet, it is clear that the temporal consistency of a document has a direct impact on the quality of the presentation and consequently on the client satisfaction (consider the case of a presentation that stops playing before its end, a part of its semantic is lost). In order to address the lack in SMIL modelling and verification solutions, we have defined a hierarchical temporal extension of Petri Nets, named H-SMIL-Net (Hierarchical SMIL-Petri Net) (Bouyakoub & Belkhir, 2008), for the incremental authoring of SMIL multimedia documents. The H-SMIL-Net model is mapped on the SMIL hierarchical temporal structure to better fit with the modelling needs of this language.…”