Method and apparatus for processing a video signal
The present invention discloses a method and apparatus for encoding or decoding a video signal. The method for processing a video signal according to the present invention uses a merging mode in which prediction information on a neighbor unit is used instead of transmitting prediction information on the present unit, so as to improve coding efficiency. In this case, the number of available candidate units for merging among the units in a predetermined position is determined, and information for the merging mode is acquired on the basis of the number of the available candidate units for merging. The unit to be merged is determined using the information for the merging mode, and prediction information on the unit to be merged is acquired. The prediction value for the present unit is acquired using the prediction information on the unit to be merged, and the present unit is restored using the acquired prediction value.
1. A method for encoding a video signal comprising at least one coding block by an encoding apparatus, the method comprising:
obtaining, by the encoding apparatus, a plurality of prediction blocks being partitioned from the coding block;
obtaining, by the encoding apparatus, merge flag information indicating whether prediction information of a current prediction block of the plurality of prediction blocks is determined by prediction information of a merging candidate selected from merging candidates, the merging candidates comprising at least one neighboring prediction block adjacent to the current prediction block; and
encoding, by the encoding apparatus, the current prediction block based on the prediction information of the selected merging candidate when the merge flag information indicates that the prediction information of the current prediction block is determined by the prediction information of the selected merging candidate,
wherein, when the coding block is partitioned into two prediction blocks each of which has a horizontal size greater than a vertical size, and the current prediction block is a bottom prediction block of the two prediction blocks, a top prediction block of the two prediction blocks is not included in the merging candidates.
2. The method of claim 1 , wherein each of the prediction information comprises reference index information and motion vector information of a corresponding prediction block.
3. The method of claim 1 , wherein, when the coding block is partitioned into two prediction blocks each of which has a vertical size greater than a horizontal size, and the current prediction block is a right prediction block of the two prediction blocks, a left prediction block of the two prediction blocks is not included in the merging candidates.
4. The method of claim 1 , wherein the at least one neighboring prediction block includes at least one of a left neighboring prediction block, a top neighboring prediction block, a top-left neighboring prediction block, a top-right neighboring prediction block, or a bottom-left neighboring prediction block.
5. The method of claim 4 , wherein, when prediction information of the top neighboring prediction block is identical to prediction information of the left neighboring prediction block, the top neighboring prediction block is not included in the merging candidates.
6. The method of claim 1 , wherein merge index information is encoded when a number of the at least one neighboring prediction block included in the merging candidates is greater than one.
7. The method of claim 6 , wherein the selected merging candidate is indicated by the merge index information from among the merging candidates.
8. The method of claim 1 , wherein the merging candidates include at least one spatial merging candidate and at least one temporal merging candidate, and
wherein the spatial merging candidate corresponds to a neighboring prediction block adjacent to the current prediction block within a picture including the current prediction block, and the temporal merging candidate corresponds to a prediction block located in a different picture than the picture including the current prediction block.
9. The method of claim 8 , wherein the at least one spatial merging candidate includes up to five neighboring prediction blocks adjacent to the current prediction block.
10. The method of claim 8 , wherein a maximum number of the merging candidates is six.
11. An encoding apparatus for encoding a video signal comprising at least one coding block, the encoding apparatus comprising:
an inter prediction unit configured to:
obtain a plurality of prediction blocks being partitioned from the coding block;
obtain merge flag information indicating whether prediction information of a current prediction block of the plurality of prediction blocks is determined by prediction information of a merging candidate selected from merging candidates, the merging candidates comprising at least one neighboring prediction block adjacent to the current prediction block; and
encode the current prediction block based on the prediction information of the selected merging candidate when the merge flag information indicates that the prediction information of the current prediction block is determined by the prediction information of the selected merging candidate,
wherein, when the coding block is partitioned into two prediction blocks each of which has a horizontal size greater than a vertical size, and the current prediction block is a bottom prediction block of the two prediction blocks, a top prediction block of the two prediction blocks is not included in the merging candidates.
12. The encoding apparatus of claim 11 , wherein each of the prediction information comprises reference index information and motion vector information of a corresponding prediction block.
13. The encoding apparatus of claim 11 , wherein, when the coding block is partitioned into two prediction blocks each of which has a vertical size greater than a horizontal size, and the current prediction block is a right prediction block of the two prediction blocks, a left prediction block of the two prediction blocks is not included in the merging candidates.
14. The encoding apparatus of claim 11 , wherein the at least one neighboring prediction block includes at least one of a left neighboring prediction block, a top neighboring prediction block, a top-left neighboring prediction block, a top-right neighboring prediction block, or a bottom-left neighboring prediction block.
15. The encoding apparatus of claim 14 , wherein, when prediction information of the top neighboring prediction block is identical to prediction information of the left neighboring prediction block, the top neighboring prediction block is not included in the merging candidates.
16. The encoding apparatus of claim 11 , wherein merge index information is encoded when a number of the at least one neighboring prediction block included in the merging candidates is greater than one.
17. The encoding apparatus of claim 16 , wherein the selected merging candidate is indicated by the merge index information from among the merging candidates.
18. The encoding apparatus of claim 11 , wherein the merging candidates include at least one spatial merging candidate and at least one temporal merging candidate, and
wherein the spatial merging candidate corresponds to a neighboring prediction block adjacent to the current prediction block within a picture including the current prediction block, and the temporal merging candidate corresponds to a prediction block located in a different picture than the picture including the current prediction block.
19. The encoding apparatus of claim 18 , wherein the at least one spatial merging candidate includes up to five neighboring prediction blocks adjacent to the current prediction block.
20. The encoding apparatus of claim 18 , wherein a maximum number of the merging candidates is six.
21. A computer readable recording medium in which a bitstream generated by the method of claim 1 is stored.