Error-Resilient H.264/AVC Video Transmission Using Two-Way Decodable Variable Length Data Block

Standard video coders utilize variable length coding (VLC) to obtain more data compression in addition to what lossy coding has achieved at the expense of making the compressed bitstream very vulnerable to channel errors. Even a 1-bit error incurred in the bitstream may cause the follow-up bitstream to be either erroneously decoded or completely undecodable, and this could further result in error propagation. To mitigate this phenomenon, a new VLC coding scheme is proposed in this paper, called the two-way decodable variable length data block (TDVLDB), which allows the compressed bitstream to be bidirectionally decodable without exploiting data partitioning. The proposed TDVLDB scheme is able to effectively recover more uncorrupted data from the corrupted packets. Furthermore, it is able to correct some, if not all, channel errors of a finite-length burst error. To effectively identify the location of the first actual error incurred within the current slice, a bitstream similarity measurement (BSM) algorithm is proposed. Note that the proposed TDVLDB scheme is generic in the sense that it can be exploited in any image or video coding framework as long as it involves the use of VLC and requires error-resilience capability. In this paper, the proposed TDVLDB is incorporated into the H.264/advanced video coding (AVC) coder to evaluate its error-resilience performance in terms of rate-distortion coding efficiency. Compared with the baseline H.264/AVC coding, the TDVLDB-incorporated H.264/AVC-based coding scheme has demonstrated significant objective and subjective video quality improvements when the bitstream is transmitted over error-prone channels.