This paper presents a tool for exploring different parallelization options for an application. It can be used to quickly find a high-quality match between an application and a multi-processor platform architecture. By specifying the parallelization at a high abstraction level, and leaving the actual source code transformations to the tool, a designer can try out many parallelizations in a short time. A parallelization may use either functional or data-level splits, or a combination of both. An accompanying high-level simulator provides rapid feedback about the expected performance of a parallelization, based on platform parameters and profiling data of the sequential application on the target processor. The use of the tool and simulator are demonstrated on an MPEG-4 video encoder application and two different platform architectures.