A method and apparatus for encoding video signals of a main layer using motion vectors of predictive image frames of an auxiliary layer and decoding such encoded video data is provided. In the encoding method, a video signal is encoded in a scalable MCTF scheme to output an enhanced layer (EL) bitstream and encoded in another specified scheme to output a base layer (BL) bitstream. During MCTF encoding, information regarding a motion vector of an image block in an arbitrary frame in a frame sequence of the video signal is recorded using a motion vector of a block, which is present, at a position corresponding to the image block, in an auxiliary frame present in the BL bitstream and temporally separated from the arbitrary frame. Using the correlation between motion vectors of temporally adjacent frames in different layers reduces the amount of coded motion vector data.