Code generation for the MPEG Reconfigurable Video Coding framework: From CAL actions to C functions

The MPEG reconfigurable video coding (RVC) framework is a new standard under development by MPEG that aims at providing a unified specification of current MPEG video coding technologies. In this framework, a decoder is built as a configuration of video coding modules taken from the standard ldquoMPEG toolbox libraryrdquo. The elements of the library are specified using the CAL actor language (CAL). CAL is a dataflow based language providing computation models that are concurrent and modular. This paper describes a synthesis tool that from a CAL specification automatically generates compilable C-code. Code generators are fundamental supports for the deployment and success of the MPEG RVC framework. This paper focuses on the automatic translation of CAL actions, which is the first step to a complete actor translation. The techniques described here enable to automatically generate C-code according to a finite set of rules. This approach has been used to obtain a C implementation of the IDCT module which is one element of the RVC library. The generated code is validated against the original CAL dataflow program simulated using the open dataflow environment.