Witsenhausen–Wyner Video Coding

Inspired by Witsenhausen and Wyner´s 1980 (now expired) patent on “interframe coder for video signals,” this paper presents a Witsenhausen-Wyner video codec, where the motion-compensated previously decoded video frame is used at the decoder as side information for joint decoding. Specifically, we replace predictive Inter coding in H.264/AVC by the syndrome-based coding scheme of Witsenhausen and Wyner, while keeping the Intra and Skip modes of H.264/AVC unchanged. We employ forward motion estimation at the encoder and send the motion vectors to help generate side information at the decoder, since our focus is not on low-complexity encoding. We also examine the tradeoff between the motion vector resolution and coding efficiency. Within the Witsenhausen-Wyner coding mode, we optimize the decision between syndrome coding and entropy coding among different discrete cosine transform (DCT) bands and among different bit-planes within each DCT coefficient. Extensive simulations of video transmission over wireless networks show that Witsenhausen-Wyner video coding is more robust against channel errors than H.264/AVC. The price paid for enhanced error-resilience with Witsenhausen-Wyner coding is a small loss in compression efficiency.