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.

Multimedia coding technology, after about 20 years of active research, has delivered a rich variety of different and complex coding algorithms. Selecting an appropriate subset of these algorithms would, in principle, enable a designer to produce the codec supporting any desired functionality as well as any desired trade-off between compression performance and implementation complexity. Currently, interoperability demands that this selection process be hard-wired into the normative descriptions of the codec, or at a lower level, into a predefined number of choices, known as profiles, codified within each standard specification. This paper presents an alternative paradigm for codec deployment that is currently under development by MPEG, known as Reconfigurable Media Coding (RMC). Using the RMC framework, arbitrary combinations of fundamental algorithms may be assembled, without predefined standardization, because everything necessary for specifying the decoding process is delivered alongside the content itself. This side-information consists of a description of the bitstream syntax, as well as a description of the decoder configuration. Decoder configuration information is provided as a description of the interconnections between algorithmic blocks. The approach has been validated by development of an RMC format that matches MPEG-4 Video, and then extending the format by adding new chroma-subsampling patterns. ABSTRACT Multimedia coding technology, after about 20 years of active research, has delivered a rich variety of different and complex coding algorithms. Selecting an appropriate subset of these algorithms would, in principle, enable a designer to produce the codec supporting any desired functionality as well as any desired trade-off between compression performance and implementation complexity. Currently, interoperability demands that this selection process be hard-wired into the normative descriptions of the codec, or at a lower level, into a predefined number of choices, known as profiles, codified within each standard specification. Disciplines Physical Sciences and MathematicsThis paper presents an alternative paradigm for codec deployment that is currently under development by MPEG, known as Reconfigurable Media Coding (RMC). Using the RMC framework, arbitrary combinations of fundamental algorithms may be assembled, without predefined standardization, because everything necessary for specifying the decoding process is delivered alongside the content itself. This sideinformation consists of a description of the bitstream syntax, as well as a description of the decoder configuration. Decoder configuration information is provided as a description of the interconnections between algorithmic blocks. The approach has been validated by development of an RMC format that matches MPEG-4 Video, and then extending the format by adding new chroma-subsampling patterns.

Reconfigurable Video Coding on Multicore T he current monolithic and lengthy scheme behind the standardization and the design of new video coding standards is becoming inappropriate to satisfy the dynamism and changing needs of the video coding community. Such scheme and specification formalism does not allow the clear commonalities between the different codecs to be shown, at the level of the specification nor at the level of the implementation. Such a problem is one of the main reasons for the typically long interval elapsing between the time a new idea is validated until it is implemented in consumer products as part of a worldwide standard. The analysis of this problem originated a new standard initiative within the International Organization for Standardization (ISO)/ International Electrotechnical Commission (IEC) Moving Pictures Experts Group (MPEG) committee, namely Reconfigurable Video Coding (RVC). The main idea is to develop a video coding standard that overcomes many shortcomings of the current standardization and specification process by updating and progressively incrementing a modular library of components. As the name implies, flexibility and reconfigurability are new attractive features of the RVC standard. Besides allowing for the definition of new codec algorithms, such features, as well as the dataflow-based specification formalism, open the way to define video coding standards that expressly target implementations on platforms with multiple cores. This article provides an overview of the main objectives of the new RVC standard, with an emphasis on the features that enable efficient implementation on platforms with multiple cores. A brief introduction to the methodologies that efficiently map RVC codec specifications to multicore platforms is accompanied with an example of the possible breakthroughs that are expected to occur in the design and deployment of multimedia services on multicore platforms.

The upcoming Reconfigurable Video Coding (RVC) standard from MPEG (ISO / IEC SC29WG11) defines a library of coding tools to specify existing or new compressed video formats and decoders. The coding tool library has been written in a dataflow/actororiented language named CAL. Each coding tool (actor) can be represented with an extended finite state machine and the data communication between the tools are described as dataflow graphs. This paper proposes an approach to model the CAL actor network with Parameterized Synchronous Data Flow and to derive a quasi-static multiprocessor execution schedule for the system. In addition to proposing a scheduling approach for RVC, an extension to the well-known permutation flow shop scheduling problem that enables rapid runtime scheduling of RVC tasks, is introduced.

The upcoming Reconfigurable Video Coding (RVC) standard from MPEG (ISO/IEC SC29WG11) defines a library of coding tools to specify existing or new compressed video formats and decoders. The coding tool library has been written in a dataflow/actor-oriented language named CAL. Each coding tool can be represented with an extended finite state machine and the dependencies between the tools are described as dataflow graphs. This paper proposes an approach to derive a multiprocessor execution schedule for RVC systems that are comprised of CAL actors. In addition to proposing a scheduling approach for RVC, an extension to the well-known permutation flow shop scheduling problem that enables rapid run-time scheduling of RVC tasks is introduced.

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Video coding technology has evolved in the past years into a variety of different and complex algorithms. So far the specification of such standard algorithms has been done case by case providing monolithic textual and reference SW specifications, but without any attention on commonalities and the possibility of incremental improvements or modifications of such monolithic standards. The MPEG Reconfigurable Video Coding (RVC) framework is a new ISO standard, currently under development aiming at providing video codec specifications at the level of library functions instead of monolithic algorithms. The possibility to select a subset of standard coding algorithms to specify a decoder that satisfies application specific constraints is very attractive. However, such possibility to reconfigure codecs requires systematic procedures and tools capable of describing the new bitstream syntaxes of such new codecs. Moreover, it is also necessary to generate the associated parsers which are capable to parse the new bitstreams because they are not available "a priori" in the RVC library. This paper further explains the problem and describes the technologies used to describe new bitstream syntaxes within RVC. In addition, the paper describes the methodology and the tools for the validation of bitstream syntaxes descriptions as well as an example of systematic procedures for the direct synthesis of parsers in the same data flow formalism in which the RVC library component are implemented.

Nowadays, the design flow of complex signal processing embedded systems starts with a specification of the application by means of a large and sequential program (usually in C/C++). As we are entering in the multicore era, sequential programs are no longer the most appropriate way to specify algorithms targeted to run on several processing units. The new ISO/MPEG Reconfigurable Video Coding (RVC) standard is proposing a new paradigm for specifying and designing complex signal processing systems. The RVC standard enables specifying new codecs by assembling blocks, or so called Functional Units (FUs) from a standard Video Tool Library (VTL). Flexibility, reusability, and modularity are the key features of RVC. This new way of specifying algorithms clearly simplifies the task of designing future video coding applications by allowing software and hardware reuse across multiple video coding standards. Specifications are provided in the form of an actor and dataflow-based language called CAL. Although the RVC standard does not imply any specific implementation design flow, it is an appropriate starting point for targeting multiple processing units platforms. This paper describes a new model-driven design flow which considers both algorithm and architecture to map RVC codec specifications onto heterogeneous and multi-core systems.