電機工程學系 ; © 2005 Institute of Electrical and Electronics © 2005 Institute of Electrical and Electronics Engineers-Engineers-Video transcoding, due to its high practical values for a wide range of networked video applications, has become an active research topic. In this paper, we outline the technical issues and research results related to video transcoding. We also discuss techniques for reducing the complexity, and techniques for improving the video quality, by exploiting the information extracted from the input video bit stream