The context of this work is the design of embedded systems targeting multimedia applications. More specifically we address the problem of design space exploration at high levels of abstraction, early in the design process. In this paper we present Design Trotter, a framework for guiding system designers. The main features of Design Trotter are the characterization of the application by means of metrics, the exploration of the application parallelisms by means of dynamic trade-off curves and the possibilities of performance estimations onto hardware and software targets. We present some results on a real-life application showing how the designer can benefit from our approach.