Method for storing motion information and method for inducing temporal motion vector predictor using same
A motion information storing method and a TMVP deriving method using the motion information storing method are provided. The motion information storing method includes a step of determining a representative block out of blocks of a motion data storage unit in a co-located picture with a current picture and a step of storing motion information of the representative block as motion information of the motion data storage unit, wherein the motion information of the representative block is used as motion information of the blocks included in the motion data storage unit.
1. A method for decoding a video signal comprising:
setting motion information of a co-located prediction block as a temporal motion vector predictor of a current block, wherein the co-located prediction block is a block corresponding to the current block, and the co-located prediction block is located in a co-located picture of a current picture;
deriving motion vector of the current block based on the temporal motion vector predictor and a motion vector difference;
performing inter prediction on the current block using the motion vector of the current block; and
reconstructing samples of the current picture based on the inter prediction,
wherein the co-located prediction block is a prediction block covering the top-left corner in a motion data storage unit area including a positioning pixel for the co-located prediction block, and the positioning pixel is a pixel adjacent to the right-bottom corner of a co-located block of the current block in the co-located picture.
2. The method according to claim 1 , wherein when the pixel adjacent to the right-bottom corner of the co-located block is a pixel which is not available for the inter prediction, a pixel at the right-bottom pixel out of four pixels located at the center of the co-located block is selected as the positioning pixel.
3. The method according to claim 2 , wherein a size of the motion data storage unit area is 16×16 samples.
4. The method according to claim 1 , wherein the co-located prediction block is any one of a prediction unit located at the center of the motion data storage unit area and a prediction unit adjacent to the right-bottom corner of the motion data storage unit area.
5. The method according to claim 1 , wherein the right-bottom pixel out of four pixels located at the center of the co-located block is selected as the positioning pixel when a bottom of the co-located block is a boundary of the largest coding unit.
6. The method according to claim 1 , wherein the right-bottom pixel out of four pixels located at the center of the co-located block is selected as the positioning pixel when the pixel adjacent to the right-bottom corner of the co-located block is a boundary of the largest coding unit.
7. The method according to claim 1 , wherein the motion information of the co-located prediction block at the top-left corner in the motion data storage unit is used as a motion vector of a prediction block in the motion data storage unit area.
8. The method according to claim 1 , wherein availability information is signaled, the availability information indicating whether the temporal motion vector predictor can be used for the current picture, and
wherein the temporal motion vector predictor is derived when the availability information does not indicate that temporal motion vector predictor is not used for the current picture.