OPTIMIZATION-BASED MULTIMEDIA ADAPTATION DECISION-TAKING

Synonym: Finding parameters for multimedia content adaptation utilizing optimization techniques. Definition: Optimization-based multimedia adaptation decision-taking is referred to as the process of finding the optimal selection of parameter settings for the actual multimedia content adaptation engines that satisfy given constraints while maximizing Quality of Service (QoS). Problem Description Multimedia content adaptation is regarded as a key technology to enable the vision of Universal Multimedia Access (UMA) [1]. UMA refers to the idea that multimedia content can be consumed anytime and anywhere, regardless of the end device and the delivery networks. Since the adaptation of a multimedia content can be performed along different dimensions, e.g., a video can be reduced in either spatial or temporal resolution or a combination of both, a variety of adaptation possibilities arise. The task of adaptation decision-taking is to determine which adaptation operations should finally be performed on the multimedia content in order to close the mismatch between the initial content and the final content variation that suits, e.g., device and network capabilities while maximizing Quality of Service (QoS). The outcome of this decision-taking process can be seen as a set of adaptation parameters that steer the actual multimedia content adaptation engines. The high-level architecture of a multimedia content delivery framework is depicted in Figure 1. A central module of this framework is the adaptation decision-taking engine (ADTE) which is the main topic of this article. Its task is to perform adaptation decision-taking as defined above, i.e., to provide the optimal parameter settings for the actual multimedia content adaptation engine that satisfy the given constraints while maximizing QoS. The input to the ADTE is a set of constraints which can be divided into two categories. The first category comprises constraints that emanate from the content consumer and are transmitted to the multimedia service provider; these are generally A