Overview of the MPEG Reconfigurable Video Coding Framework

Abstract

Video coding technology in the last 20 years has evolved producing a variety of different and complex algorithms and coding standards. So far the specification of such standards, and of the algorithms that build them, has been done case by case providing monolithic textual and reference software specifications in different forms and programming languages. However, very little attention has been given to provide a specification formalism that explicitly presents common components between standards, and the incremental modifications of such monolithic standards. The MPEG Reconfigurable Video Coding (RVC) framework is a new ISO standard currently under its final stage of standardization, aiming at providing video codec specifications at the level of library components instead of monolithic algorithms. The new concept is to be able to specify a decoder of an existing standard or a completely new configuration that may better satisfy applicationspecific constraints by selecting standard components from a library of standard coding algorithms. The possibility of dynamic configuration and reconfiguration of codecs also requires new methodologies and new tools for describing the new bitstream syntaxes and the parsers of such new codecs. The RVC framework is based on the usage of a new actor/dataflow oriented language called Cal for the specification of the standard library and instantiation of the RVC decoder model. This language has been specifically designed for modeling complex signal processing systems. Cal dataflow models expose the intrinsic concurrency of the algorithms by employing the notions of actor programming and dataflow. The paper gives an overview of the concepts and technologies building the standard RVC framework and the non standard tools supporting the RVC model from the instantiation and simulation of the Cal model to software and/or hardware code synthesis.

A unified hardware/software co-synthesis solution for signal processing systems

“…The RVC-CAL language is a subset of the CAL language and it is normalized by ISO/IEC as a part of the RVC standard. Although it has some restrictions in data types and features that are in used in CAL [4,6], is sufficient and efficient for specifying streaming and signal processing systems such as MPEG compression technology. …”

Performance benchmarking of RVC based multimedia specifications

“…Initially, the RVC framework was developed to handle the challenges incurred in the development of complicated video codecs [3,4], which can naturally be modeled as dataflow systems. But the RVC standard actually offers a general development framework and has also been used for the development of other types of media (3-D graphics [5], image [6], audio [7]) codecs and secure computing systems [8][9][10], as structurally they are all data-driven.…”

Automatic generation of synthesizable hardware implementation from high level RVC-cal description

“…In this context, CAL Actor Language [1] was introduced in the Ptolemy II project [2] as a dataflow target agnostic language. The MPEG community standardized the RVC-CAL language [3] in the MPEG-RVC (Reconfigurable Video Coding) standard [4]. This standard provides a framework to describe the different functions of a codec as a network of functional blocks developed in RVC-CAL and called actors.…”