Time in documents - The SMIL language

For over 25 years, electronic documents have been the subject of studies that have led to the identification of characteristics attached to documents and classified according to different dimensions . The major result of this work has been the definition of standards such as XML (eXtended Markup Language), which have made it possible to represent the logical dimension of documents independently of their content and spatial dimension (form), thus facilitating document portability and processing by a variety of applications. Web technologies have largely built on these concepts, with the definition of HTML on the one hand and CSS on the other. With the integration of timed data such as video, sound or moving objects on the screen, electronic documents now have a temporal dimension in addition to the spatial, logical and hypertext dimensions . This evolution is the result of the new technological capabilities of computers and mobile terminals (CPU, memory, multimedia peripherals, CD-ROM supports, disks, etc.), networks (data rates, protocols) and digital processing techniques for non-textual information: sounds, static and dynamic images (coding, compression/decompression). As a result, access to documentary information is becoming increasingly widespread, in multimedia form and via a wide variety of terminals, the main medium being the Web. Finally, it is the Web languages that have gradually integrated multimedia properties, whether to express content synchronization (HTML5, SMIL), temporal navigation (Xlink), user interaction or spatio-temporal animation (SVG).

In this article, we present the concepts and requirements involved in introducing the temporal dimension into electronic documents, hereafter referred to as multimedia documents, as well as current solutions in this field: existing tools, standards, research...