Method and device using inter prediction information
Disclosed herein are a video decoding method and apparatus and a video encoding method and apparatus. In video encoding and decoding, inter-prediction information for a target block may be derived, and inter prediction for a target block may be performed using the derived inter-prediction information. Combined inter-prediction information may be performed by combining multiple pieces of inter-prediction information, and the combined inter-prediction information may be added as a candidate to a list used for inter prediction. One of candidates in the list may be selected for inter prediction for the target block, and inter prediction using the selected candidate may be performed.
1. A video decoding method, comprising:
deriving inter prediction information for a target block; and
performing prediction for the target block using the inter prediction information, wherein:
a first list comprising a plurality of first candidates is configured for the target block,
the prediction is performed using the first list,
a candidate of a second list comprising a plurality of second candidates is used to add a candidate to the first list, and
the inter prediction information for the target block is added to the second list.
2. The video decoding method of claim 1 , wherein
the plurality of first candidates are generated based on a plurality of neighbor blocks which are adjacent to the target block, and
the plurality of neighbor blocks include a left-most block among blocks adjacent to an upper side of the target block and an upper-most block among blocks adjacent to a left side of the target block.
3. The video decoding method of claim 1 , wherein
the plurality of first candidates are generated by adding prediction information of a plurality of neighbor blocks which are adjacent to the target block to the first list according to a specific order,
according to the specific order, prediction information of an above neighbor block is added to the first list first, prediction information of a left neighbor block is added to the first list second,
the above neighbor block is a right-most block among blocks which are adjacent to an upper side of the target block, and
the left neighbor block is a lower-most block among block which are adjacent to a left side of the target block.
4. The video decoding method of claim 1 , wherein
one candidate of the first list is generated based on prediction information of a plurality of neighbor blocks which are adjacent to the target block.
5. The video decoding method of claim 4 , wherein
the one candidate is an average of two prediction information of two neighbor blocks.
6. The video decoding method of claim 4 , wherein
the one candidate is generated based on prediction information of three neighbor blocks.
7. The video decoding method of claim 1 , wherein
the inter prediction information comprises a motion vector, and
the motion vector is generated by a refinement for an initial motion vector.
8. The video decoding method of claim 7 , wherein
the refinement is performed using a Sum of Absolute Differences (SAD) between two reference blocks.
9. A video encoding method, comprising:
deriving inter prediction information for a target block; and
generating an indicator indicating a method to derive the inter prediction information, wherein:
a first list comprising a plurality of first candidates is configured for the target block,
prediction is performed using the inter prediction information corresponding one of the plurality of first candidates,
a candidate of a second list comprising a plurality of second candidates is used to add a candidate to the first list, and
the inter prediction information for the target block is added to the second list.
10. The video encoding method of claim 9 , wherein
the plurality of first candidates are generated based on a plurality of neighbor blocks which are adjacent to the target block, and
the plurality of neighbor blocks include a left-most block among blocks adjacent to an upper side of the target block and an upper-most block among blocks adjacent to a left side of the target block.
11. The video encoding method of claim 9 , wherein
the plurality of first candidates are generated by adding prediction information of a plurality of neighbor blocks which are adjacent to the target block to the first list according to a specific order,
according to the specific order, prediction information of an above neighbor block is added to the first list first, prediction information of a left neighbor block is added to the list first second,
the above neighbor block is a right-most block among blocks which are adjacent to an upper side of the target block, and
the left neighbor block is a lower-most block among block which are adjacent to a left side of the target block.
12. The video encoding method of claim 9 , wherein
one candidate of the first list is generated based on prediction information of a plurality of neighbor blocks which are adjacent to the target block.
13. The video encoding method of claim 12 , wherein
the one candidate is an average of two prediction information of two neighbor blocks.
14. The video encoding method of claim 12 , wherein
the one candidate is generated based on prediction information of three neighbor blocks.
15. The video encoding method of claim 9 , wherein
a prediction is performed using the inter prediction information for a decoding for the target block using the indicator,
the inter prediction information comprises a motion vector, and
the motion vector is generated by a refinement for an initial motion vector.
16. The video encoding method of claim 15 , wherein
the refinement is performed using a Sum of Absolute Differences (SAD) between two reference blocks.
17. A non-transitory computer-readable medium storing a bitstream generated by the video encoding method of claim 9 .
18. A non-transitory computer-readable medium storing a bitstream, the bitstream comprising:
merge index;
wherein inter prediction information for a target block is derived,
prediction for the target block is performed using the merge index and the inter prediction information,
a first list comprising a plurality of first candidates is configured for the target block,
the merge index indicates one of the plurality of first candidates to be used for the prediction,
the prediction is performed using the first list,
a candidate of a second list comprising a plurality of second candidates is used to add a candidate to the first list, and
the inter prediction information for the target block is added to the second list.