Video encoding/decoding method and apparatus in temporal direct mode in hierarchical structure

A video encoder for performing encoding in a temporal direct mode in order to predict a high-pass frame in a multilayer video signal, the video encoder comprising:

• a motion vector extraction unit which obtains at least one of a temporal position of a forward reference frame and a backward reference frame of the high-pass frame, and searches for at least one frame existing at the temporal position and having motion vector information,
• wherein, the motion vector extraction unit finds a plurality of frames for at least one high pass frame and the motion vector extraction unit selects as a co-located frame a frame, among the plurality of frames, having a motion vector of which an interval is closest to a difference in interval between the forward reference frame and the backward reference frame of the high-pass frame, and extracts the motion vector of the selected frame;
• and
• a temporal direct-mode encoding unit which encodes information on the selected frame,
• wherein the interval of the motion vector is a difference between a picture order count (POC) of a frame which has the motion vector and a POC of a frame which is referred to by the motion vector, and
• wherein the difference in interval between the forward reference frame and the backward reference frame of the high-pass frame is a difference of a POC of the forward reference frame of the high-pass frame and a POC of the backward reference frame of the high-pass frame,
• wherein the selecting of the co-located frame comprises determining which frame among the plural frames has the motion vector, the interval of which has a POC difference that is closest to the difference of the POC of the forward reference frame of the high-pass frame and the POC of the backward reference frame of the high-pass frame.