This　paper　presents　an　efficient　mode　decision　scheme　for　down-sizing　video　transcoding　in　H.264　using　support　vector　machines　(SVMs).　In　order　to　reduce　the　high　computational　complexity　of　using　conventional　mode　decision　in　the　H.264　re-encoder,　the　proposed　scheme　uses　SVMs　to　exploit　the　correlation　between　coding　information　extracted　from　the　input　high-resolution　bit-stream　and　the　coding　modes　of　macroblocks　in　down-sized　video　frames.　After　the　SVMs　classifier,　improbable　modes　are　eliminated　and　only　a　small　number　of　candidate　modes　are　carried　out　using　the　RDO　operations.　Hence,　remarkable　computing　time　can　be　saved,　while　maintaining　nearly　the　same　quality　of　the　transcoded　pictures.