Method of Scalable Video Coding and the Codec Using the Same

摘要

Since joint scalable video coding (JSVC) adopts a scheme in which numbers are assigned to all of the pictures according to the order in which the pictures are displayed, it is difficult to detect a drop (or loss) of a key picture and thus it is difficult to effectively take action against an error caused by the loss of the key picture. The present invention provides a coding method of detecting a loss of a key picture by numbering key pictures in JSVC in which predictive (P) pictures have a closed-loop structure and of effectively taking action against an error in the case of a loss of a key picture, and a codec using the coding method. The SVC method includes performing encoding while assigning a number to a key picture of an upper layer and performing decoding with respect to the number-encoded current key picture of the upper layer using data of a decoded image of a picture of a lower layer that is temporally matched with the current key picture of the upper layer when a loss of a key picture between the number-encoded current key picture of the upper layer and a previous key picture that is number-encoded prior to the current key picture is detected. Therefore, it is possible to effectively take action against to an error caused by a loss of a key picture by detecting the loss of a key picture during decoding by encoding using numbering of key pictures in JSVC in which closed-loop coding is performed by consecutively predicting key pictures. Moreover, it is possible to minimize degradation in image quality by concealing an error caused by an incorrect reference by using data of a decoded image of a corresponding picture of a lower base layer when a key picture of an upper layer is lost in an environment where transmission of the lower base layer is guaranteed with a video stream having a multi-layered structure.