MPEG Reconfigurable Video Coding: From specification to a reconfigurable implementation

International audienceThis paper demonstrates that it is possible to produce automatic, reconfigurable, and portable implementations of multimedia decoders onto platforms with the help of the MPEG Reconfigurable Video Coding (RVC) standard. MPEG RVC is a new formalism standardized by the MPEGconsortium used to specify multimedia decoders. It produces visual representations of decoder reference software, with the help of graphs that connect several coding tools from MPEG standards. The approach developed in this paper draws on Dataflow Process Networks to produce a Minimal and Canonical Representation (MCR) of \MPEG\ \RVC\ specifications. The \MCR\ makes it possible to form automatic and reconfigurable implementations of decoders which can match any actual platforms. The contribution is demonstrated on one case study where a generic decoder needs to process a multimedia content with the help of the \RVC\ specification of the decoder required to process it. The overall approach is tested on two decoders from MPEG, namely MPEG-4 part 2 Simple Profile and MPEG-4 part 10 Constrained Baseline Profile. The results validate the following benefits on the \MCR\ of decoders: compact representation, low overhead induced by its compilation, reconfiguration and multi-core abilities

A portable Video Tool Library for MPEG Reconfigurable Video Coding using LLVM representation

International audienceMPEG Reconfigurable Video Coding (RVC) represents the last answer of MPEG to overcome the lack of interoperability between codecs deployed in the market nowadays. The main goal of MPEG RVC is to provide a set of coding tools employed in all MPEG standards, the Video Tools Library (VTL), encapsulated into independent entities called Functional Units (FUs). FUs are described as dataflow actors in RVC-CAL actor language (RVC-CAL) and decoders are described as dataflow programs with the Abstract DecoderModels (ADMs). Therefore, an ADM of an MPEG decoder corresponds in MPEG RVC to a network of FUs taken from the VTL. The typical use of MPEG RVC is to translate an ADM into a hardware or software description language that target one specific platform. In [1], we propose to skip this synthesis process of ADM and to directly integrate a portable version of VTL described in the Low-Level Virtual Machine Intermediate Representation (LLVM IR) inside platforms. This portable VTL is couple with a new RVC Decoder, we called Just-In-Time Adaptive Decoder Engine (Jade), that dynamically instantiates ADM to decode any encoded video using its associated network description. In this paper, we introduce the different compiling steps required to obtain an automatically translation of a VTL described in RVC-CAL into a portable VTL described in LLVM. This translation is based on a new RVC-CAL compiler called Open RVC-CAL Compiler (Orcc)

A non-rigid registration approach for quantifying myocardial contraction in tagged MRI using generalized information measures.

International audienceWe address the problem of quantitatively assessing myocardial function from tagged MRI sequences. We develop a two-step method comprising (i) a motion estimation step using a novel variational non-rigid registration technique based on generalized information measures, and (ii) a measurement step, yielding local and segmental deformation parameters over the whole myocardium. Experiments on healthy and pathological data demonstrate that this method delivers, within a reasonable computation time and in a fully unsupervised way, reliable measurements for normal subjects and quantitative pathology-specific information. Beyond cardiac MRI, this work redefines the foundations of variational non-rigid registration for information-theoretic similarity criteria with potential interest in multimodal medical imaging

Towards a multimedia remote viewer for mobile thin clients

Be there a traditional mobile user wanting to connect to a remote multimedia server. In order to allow them to enjoy the same user experience remotely (play, interact, edit, store and share capabilities) as in a traditional fixed LAN environment, several dead-locks are to be dealt with: (1) a heavy and heterogeneous content should be sent through a bandwidth constrained network; (2) the displayed content should be of good quality; (3) user interaction should be processed in real-time and (4) the complexity of the practical solution should not exceed the features of the mobile client in terms of CPU, memory and battery. The present paper takes this challenge and presents a fully operational MPEG-4 BiFS solution

HANDLING MULTILINGUAL CONTENT IN DIGITAL MEDIA: A CRITICAL ANALYSIS

This document expresses and analyzes the need to define a generic method for representing multilingual information in multimedia data. It describes the basic requirements that would bear upon such representations and establishes the potential link with ISO committee TC 37/SC 4 (Language Resource Management) and with XMT (eXtended MPEG-4 Textual format)

3D versus 2D/3D shape descriptors: A comparative study

This paper proposes a comparative study of 3D and 2D/3D shape descriptors (SDs) for of 3D mesh model indexing and retrieval. Seven state of the art SDs are considered and compared, among which five are 3D (Optimized 3D Hough Descriptor-O3DHTD, Extended Gaussian Images- EGIs, cords length and spherical angles histograms, random triangles histogram, MPEG-7 3D shape spectrum descriptor – 3DSSD), and two 2D/3D, based on the MPEG-7 2D SDs (Contour Scale Space- CSS, and Angular Radial Transform- ART). A low complexity vector quantized (VQ) OH3DD is also proposed and considered for this comparison. Experimental results were carried out upon the categorized MPEG-7 3D test database. By computing Bull-Eye Score (BES) and First Tier (FT) criteria, it is objectively established that the O3DHTD (even in its VQ version) outperforms (BES = 81 % or 79%).all other SDs. The 2D/3D CSS-based descriptor exhibits a highly discriminant behavior (BES = 74%) outperforming the other both 3D and 2D/3D approaches. Apply to the industrial framework of the French national project SEMANTIC-3D, the O3DHTD demonstrated its relevance together with its scalability and robustness properties