For video adaptation in universal multimedia access systems, video contents have to be transcoded according to the requirements of network bandwidth and the performance of clients. However, the transcoded video streams are vulnerable to channel disturbances when they are transmitted over the wireless channels. In this paper, we present an error resilient transcoding system using the residulal motion coding method for wireless visual communications networks. The residual motion coding method interleaves into the bitstream the residual motion vector that is auxiliary motion information to be used at the decoder to recover the lost motion vector. With the residual motion vector, the decoder can precisely reproduce the motion vector of the corrupted macroblock and reconstruct the lost macroblock by using error concealment based on temporal prediction. Experimental results show that the proposed method can not only achieve the error robustness of the motion vector, but also improve the performance of error concealment at the decoder.