Iterative joint source-channel decoding aided transmission of losslessly compressed video

Abstract

Iterative source-channel decoding (ISCD) exploits the residual redundancy of the source by iteratively exchanging extrinsic information with the channel codecs to achieve robust transmission. In this treatise we propose a video codec suitable for lossless video compression and IS CD. At the encoder the spatio-temporal redundancy is partially removed at a low complexity by simply evaluating the frame difference (FD), which is then variable-length encoded (VLC). At the receiver we invoke a three-stage concatenated IS CD scheme for exploiting the residual redundancy of the FD. A Markov Random Field (MRF) model based soft-in-soft-out (SISO) module is proposed for exploiting the spatial correlations amongst the adjacent video pixels, using intra-frame coding. More explicitly, the VLC SISO decoder operates by exchanging soft information with both the MRF module and the soft channel decoder. The convergence of the three-stage iterative decoding process is examined using 3D extrinsic information transfer (EXIT) charts. Finally, we show that our system exhibits a substantial E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">b</sub> /N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">O</sub> improvement of about 5.2 dB compared to the corresponding benchmarker schemes.