Video transcoding for reduced spatial resolution needs a lot of computation.Restricted by real-time demand

the quality of transcoded stream will decrease in variant degree.In order to improve the quality of transcoded stream

a new scheme is proposed in this paper which estimates the distortion degree of downscaled texture and motion vector according to the condition of neighbor macroblocks' texture and the cluster degree of their motion vectors

and then adaptively chooses one arithmetic to transcode.Experimental results show that this scheme can bring some improvement to the quality of transcoded stream

and at the same time avoid extensive motion search and introducing much of intra-coded macroblocks.