Method for selecting motion vector predictor and device using same

A method of decoding video using motion vector of a block neighboring to a current block by decoding apparatus, the method comprising:

• deriving neighboring blocks for selecting a motion vector predictor of the current block;
• determining whether any one of the neighboring blocks satisfies a first condition that a block has a reference picture identical to that of the current block and a reference picture list identical to that of the current block;
• determining whether any one of the neighboring blocks satisfies a second condition that a block has a reference picture identical to that of the current block and a reference picture list different from that of the current block;
• setting a block out of neighboring blocks of the current block satisfied the first condition or the second condition as one of available candidate blocks;
• configuring motion vectors of the candidate blocks as motion vector predictor candidates for the current block;
• selecting a motion vector predictor of the current block out of the motion vector predictor candidates;
• generating a prediction block of the current block using a motion vector of the current block derived based on the motion vector predictor;
• and
• reconstructing the current block based on the prediction block,
• wherein a first block group consists of two neighboring blocks among the neighboring blocks, the two neighboring blocks includes a lower left neighboring block and a left neighboring block,
• wherein a second block group consists of three neighboring blocks among the neighboring blocks, the three neighboring blocks includes an upper right neighboring block, an upper neighboring block, and an upper left neighboring block,
• wherein in the first block group, whether the first condition or the second condition is satisfied or not is checked from the lower left neighboring block to the left neighboring block,
• wherein in the second block group, whether the first condition or the second condition is satisfied or not is checked from the upper right neighboring block to the upper neighboring block to the upper left neighboring block.