Robust VLC sequence decoding exploiting additional video stream properties with reduced complexity

Joint source-channel decoding of Variable Length Codes (VLC) for image and video streaming transmission over unreliable links, such as wireless networks, is a subject of increasing interest. Paper [14] shows that much more residual source redundancy can be exploited when both types of correlation: (i) the correlation between bits inside a VLC codeword as well as (ii) the correlation between VLC codewords of a VLC sequence unit (e.g. corresponding to one image block), are taken into account. Paper [15] proposes an optimum Maximum Likelihood (ML) decoder of VLC sequences which can exploit these two kinds of correlation and outperforms the existing VLC decoders. This paper proposes a reduced complexity version of this optimal VLC decoder. Simulation results show that the complexity is reduced by 5 in terms of number of possible candidates, while the performance is only slightly sub-optimal compared with the optimal version of paper [15].