Improved error resilience in mobile audio-visual communications

Low bit rate audio-visual coding algorithms are now being actively standardized in ITU and ISO/IEC. Their application to mobile multi-media communication systems is being considered. One of the most important features in this application is robustness against the transmission errors experienced in mobile radio channels. In this paper, the speech and video quality degradations due to errors are analyzed through computer simulations. ACELP and H.263 are used as representative low bit rate coding algorithms. After summarizing major causes of degradation such as variable length codes and hierarchical data structures, some techniques to improve the error resiliency of speech and video coding schemes are proposed.