Resource reservations are a very popular choice to schedule multimedia tasks. However, the high variability of the resource requirements hinders a static choice of the scheduling parameters. In this paper we address this problem by a combination of two strategies: adaptive reservations and resource reclaiming. The first one operates "locally" (using the information of a single task), the second one operates "globally" distributing unused bandwidth between the tasks. In this paper, we show by analytical results and by extensive simulations that the two techniques can be safely and usefully combined.