Model-based design is widely accepted in developing complex embedded system under intense time-to-market pressure. While it promises improved design productivity, the main bottleneck lies not in the design methodology but in constructing the initial algorithm representation in the specified model. It is particularly true if a complicated multimedia application is given in the form of a sequential reference C code. In this paper we propose a systematic procedure for converting a sequential C code to a dataflow specification that has been widely used in many design environments for DSP systems. The proposed technique is successfully applied to H.264 encoder algorithm as a case study.