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Currently, mobile technology is evolving very fast. Development of mobile devices, laptops, tablets or smartphones yield to information systems called ‘pervasive’ (i.e. make information accessible at any time, anyhow and anywhere). These systems can be used in different contextual situations depending on the user environment, his preferences and his device capabilities. Accessed information, on mobile devices, are multimedia documents composed of several media objects such as videos, audios, images, and texts. Typical examples of multimedia documents are web pages and SMIL (Synchronized Multimedia Integration Language) presentations (Bulterman et al., 2008). In fact, mobile devices have heterogeneous capabilities in terms of static features, such as screen size or dynamic hardware features such as remaining battery level and memory space. Moreover, user's mobility could prevent from playing specific multimedia documents, which leads to different contextual restrictions. For instance, the user may avoid playing video content during driving his car. Within a contextual situation, three categories of information must be managed:
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Terminal characteristics, such as screen size, battery level and available bandwidth.
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User context, such as localization and ambient noise.
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Document structure, such as preferred temporal or spatial organization.
In this paper, we are mainly interested by adapting multimedia content according to environmental constraints changes and users' needs, where each constraint corresponds to a physical handicap. The latter can be viewed as: «Reduction in a person's capacity to fulfill a social role as a consequence of impairment, inadequate training for the role, or other circumstances (Porta, 2014).
This work deals in particular with the adaptation of presentations containing Timesheet. This process requires understanding the contextual information cited above. When a contextual situation raises some constraints, multimedia documents cannot be appropriately executed on the target terminal, which requires a generic approach for modeling the context and performing a real-time adaptation of the document.
Motivation behind adopting a based handicap approach can be justified by the fact that in a multimedia adaptation process, identifying usage situations is a complex task because there are several possible situations. Therefore, it is necessary to reduce the number of adaptation possibilities. The problem concerning mobility situation is the interaction usage (e.g., Inability to: play sound, access to the screen, etc.). Consequently, a model referring to these situations must be defined. In fact, identifying physical handicaps allows referring to this kind of usages to reduce the adaptation possibilities which makes the approach by handicap more efficient than the other ones.
Adaptation operations allow transforming composed multimedia documents according to high level constraints related to:
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User environment
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Available resources
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Content description
This information is specified through a profile. The aim of the adaptation is to make the document compatible with the current context. Two adaptation types are distinguished (Kazi-Aoul, 2008): Global adaptation; where the presentation composition is adapted by transforming the temporal synchronization and the spatial position of the media. Local adaptation; where the media are adapted by applying physical transformations on them (content scaling, transcoding, etc.).