Method and apparatus for scalable encoding and decoding

The invention circle to minimize quantization error in the decoding stage by considering the distribution characteristics after performing the binarization in that, based on the tree structure relates to a method and apparatus for encoding or decoding an audio signal or a video signal in a hierarchical signal and to restore the signal, reducing the relatively maintaining a wide frequency bandwidth while the quantization noise because the encoded without reducing the bandwidth to restore the upper layer a significant frequency components perceptually human hearing to a higher layer than the sound quality It can be improved, and may also not degrade compression performance.