This paper presents a comparison between the scalable extension of H.264/AVC (SVC) and transcoding, in terms of Rate-Distortion(RD) performance and computational complexity. Both bitrate and spatial resolution reduction cases are included. Simulation results show that, in the aspect of RD performance, SVC performs significantly better in bitrate reduction and slightly better in spatial resolution reduction. Meanwhile, SVC adaptation through bitstream extraction has negligible complexity compared with transcoding1.