1. A multi-layered video decoding method comprising: (a) extracting, by a video decoder, base layer data and enhancement layer data from an input bitstream; (b) when there is no base layer frame at a same temporal position as a first enhancement layer frame, generating, by the video decoder, a motion vector of the first enhancement layer frame by referring to the motion vector for at least one frame among base layer frames present immediately before and after the same temporal position as the first enhancement layer frame; (c) reconstructing, by the video decoder, the motion vector of the enhancement layer using the generated predicted motion vector; and (d) reconstructing, by the video decoder, a video sequence from texture data of the enhancement layer using the reconstructed motion vector of the enhancement layer.