Modeling Media Synchronization with Semiotic Agents

Multimedia synchronization has been a research topic since the early days of the computer, especially in the areas of operating systems and programming. Synchronization features are available in most modern day languages in the form of wait and notify, block and resume, or event and event handler. However, this type of fundamental synchronization usually doesn´t involve event timing. As multimedia has become widely used in today´s applications, fueled by the popularity of the Internet, proper multimedia timing demands more sophisticated features than current languages provide. Current synchronization techniques consist of everything from the very theoretical to the very practical. The dilemma in this area is that theories or formal methods are not likely to be adopted by industry practitioners because there aren´t many tools to map theoretical models to implementation. On the other hand, commercial languages are sometimes only applicable to a specific problem domain or technology platform and usually work at a low level of abstraction. The dilemma here is the main motivation for the research presented in this article. The authors worked on a modeling technique that is based on a sound theoretical framework but at the same time can be easily understood and translated into implementations for different real-world applications. While different methods have different strengths and limitations, specifying a media-synchronization problem should at least cover a basic set of attributes, namely relationships between media objects and the timeline on which intervals, reference points, and events can be identified. This article presents a model, based on the concept of a semiotic agent, that is capable of expressing and manipulating these attributes.