Method and Apparatus for decoding video stream

Decoding method according to an embodiment includes receiving the encoded (encoded) bit stream (bit stream); Extracting the transform coefficient group from a bitstream; Group and determining the maximum position (Position Max) of the block comprises one or more transform coefficients of non-zero value from among the transform coefficients; Generating a control signal for using a group up to the location to the inverse transform (inverse transform) the transform coefficients corresponding to said block; And a step of restoring the video data by inverse transform the transform coefficients corresponding to said block based on the control signal.