Sequential Mpeg-4 solutions actually developed for single processors try to integrate the most functionalities as possible in an unique software, and are generally oversized compared with the actual service requirement. Moreover, they can hardly be projected onto multiprocessors targets, because of an extra load of source code and calculations, also to a sub-optimal use of the architecture parallelism. This paper introduces a distributed Mpeg-4 application, where the system part is hosted by a standard PC, and the video decoder is supported by a multi-DSPs board. In particular, we present our AVSynDEx methodology allowing an incremental building, an easy update on the video decoder description, and a quasi-automatic implementation onto a multi-C6x platform. We also define a global scheduler managing the parallel execution of the video and system applications.