Dynamic consistency checking for temporal and spatial relations in multimedia presentations

Science of Computer Programming

2015

The Nested Context Language (NCL) is a multimedia authoring language that is part of the standard for digital television in Brazil and in Latin America and the ITU standard for IPTV services. To properly support authors in the development of NCL applications, it is important to provide tools with validation capabilities. The validation of multimedia documents indicates to the author possible inconsistent points in a given document. Thus the author has the possibility of correcting those inconsistencies before making the multimedia document available for the final user. The validation approach presented in this work considers a set of desirable document properties based on related work published in the literature. Since NCL applications may be understood as finite transition systems, standard model-based validation techniques directly apply. This paper discusses a formalization of NCL semantics with rewriting theory. Two theories are given to represent (i) NCL's static semantics and (ii) NCL's dynamic semantics. In the former, NCL structural properties are validated through equational reduction, while in the latter, NCL expected behaviors are validated through searching.

“…Elias et al in [24] present an algorithm for dynamic checking spatio-temporal relations. In the paper, dynamic means that the checking is done during presentation declaration.…”

Section: Behavioral Validationmentioning

confidence: 99%

“…Both [23] and [24] perform their validation over a set of constraints representing the synchronization for a given document, reducing it until it is consistent. Our approach presents traces of document executions that fail in some behavioral property to the author.…”

Section: Behavioral Validationmentioning

confidence: 99%

A rewriting logic semantics for NCL

Science of Computer Programming

2015

“…Elias et al in [11] present an algorithm for dynamic checking spatio-temporal relations. In the paper, dynamic means that the checking is done during presentation declaration.…”

Section: Behavioral Verificationmentioning

confidence: 99%

An Executable Semantics for a Multimedia Authoring Language

Lecture Notes in Computer Science

2013

Abstract. The Nested Context Language is a multimedia authoring language which is part of the standard for digital television in Brazil and in Latin America and the ITU standard for IPTV services. The need for proper support for the development of NCL applications is growing with the increasing demand for digital TV applications. Rigorous means to assure that multimedia presentations in NCL will behave as expected is an example. Since NCL applications may be understood as finite transition systems, standard model-based verification techniques directly apply. This paper discusses a formalization of NCL semantics and its realization in a verification tool.

“…Elias et al em [12] apresentam um algoritmo para a checagem dinâmica de relações espaço-temporais. No artigo, dinâmico significa que a checagemé feita durante a declaração da apresentação.…”

Section: Análise Comportamentalunclassified

Automating the analysis of NCL documents with a model-driven approach

Proceedings of the 19th Brazilian Symposium on Multimedia and the Web

2013

This paper presents a model-driven approach for the analysis of NCL documents. Structural and behavioral properties of NCL documents are verified guaranteeing its wellformedness and conformance with respect to the NCL language semantics. Document structural properties are verified using invariant validation and document behavioral properties are verified through model checking. The modeldriven approach proposed is based on a formal and simplified model for representing the NCL document presentation behavior called Simple Hypermedia Model (SHM), used for the verification of document properties. In addition, this paper presents a prototype implementation of the proposed approach.