Robust Video Decoding through Simultaneous Usage of Residual Source Information and MAC Layer CRC Redundancy

This paper presents a MAP estimation method of CAVLC (Context Adaptive Variable Length Coding) encoded sequences for robust decoding of H.264/AVC video stream. A sequential decoding algorithm jointly exploiting the residual source information (related to VLC codes and source characteristics) along with the MAC layer CRC redundancy in the transmission scheme is proposed. The branch selection metric in the decoding trellis incorporates the usually considered APP weighted by a CRC dependent factor. We also introduce a sub-optimal but hardware realizable version of the proposed algorithm. Significant link budget improvement results have been demonstrated for transmission schemes using BPSK modulated signals sent over AWGN channels.