A New Fast Transcoder for Resizing Coded Video Sequences

Recently, many advanced video application services over the mobile wireless networks have required a transcoder which can efficiently reduce the size of compressed video bitstreams. The transcoder can be worked in either the spatial domain or the DCT domain. In this paper, we propose a new fast hybrid-type transcoder which can efficiently reduce the frame size with keeping the visual quality. The proposed scheme consists of two major processes: a transform domain process and a spatial domain process. We also propose a scheme for coding mode selection and motion vector refinement. Experimental results show that our approach can reduce the computational complexity more than any other conventional spatial-domain transcoder with keeping the visual quality.