Video encoding/decoding apparatus and method capable of minimizing random access delay

A video decoding apparatus, comprising:

• a first base layer decoding unit which decodes a base layer bitstream and enlarges the decoded base layer bitstream to the size of a corresponding original image;
• an enhancement layer decoding unit which decodes an enhancement layer image which is temporally different from the base layer bitstream by referring to the enlarged result;
• and
• a decoding control unit which controls the enlarged result to be reproduced until an I frame of the decoded enhancement layer image is reproduced and controls the decoded enhancement layer image to be displayed when the I frame of the decoded enhancement layer image is reproduced.

A video encoding method, comprising:

• setting an I-frame interval of a base layer shorter than an I-frame interval of an enhancement layer;
• generating a base layer bitstream by reducing and encoding an original image according to the I-frame intervals of the base layer and the enhancement layer;
• and
• generating an enhancement layer bitstream by decoding an enhancement layer image which is temporally different from the base layer bitstream and referring to a predetermined image obtained by decoding the base layer bitstream and enlarging the decoded result.

A video decoding method, comprising:

• decoding a base layer bitstream and enlarging the decoded base layer bitstream to the size of a corresponding original image;
• decoding an enhancement layer image which is temporally different from the base layer bitstream by referring to the enlarged result;
• and
• controlling the enlarged result to be reproduced until an I frame of the decoded enhancement layer image is reproduced and controlling the decoded enhancement layer image to be displayed when the I frame of the decoded enhancement layer image is reproduced.