Scalable video encoding and decoding method using switching pictures and apparatus thereof

A conventional new video coding technology can provide a bitstream switching picture by encoding the bitstream switching picture into an I picture. However, an encoding efficiency is greatly reduced. As such, the new video coding technology does not provide an efficient bitstream switching function. Also, other advantages provided by a switching picture technology such as a random access, error durability, and a bitstream splicing are not provided. Provided is an apparatus for encoding a video bitstream including a base layer bitstream and an enhancement layer bitstream by encoding an enhancement layer picture of the enhancement layer bitstream, which is reproduced immediately after a base layer picture of the base layer bitstream is reproduced, into a non-switching pictures by interlayer prediction using a reference image generated by decoding a pre-encoded base layer picture or by motion prediction using another reference image generated by decoding a pre-encoded enhancement layer picture, and into a switching picture, which is decoded into the same image as the non-switching picture, by an interlayer prediction using the non-switching picture and a reference image generated by decoding a pre-encoded base layer picture, while the base layer picture is being reproduced.