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 list comprising a plurality of candidates is configured for the target block,
the prediction is performed using the list,
the plurality of candidates are generated by adding prediction information of a plurality of neighbor blocks which are adjacent to the target block to the list according to a specific order,
according to the specific order, prediction information of a first neighbor block is added to the list first, prediction information of a second neighbor block is added to the list second,
the first neighbor block is a block comprising a first neighbor pixel,
the first neighbor pixel is a pixel which is vertically adjacent to an upper-side of an uppermost-rightmost pixel in the target block,
an x-coordinate of the first neighbor pixel is equal to an x-coordinate of the uppermost-rightmost pixel in the target block,
the second neighbor block is a block comprising a second neighbor pixel,
the second neighbor pixel is a pixel which is horizontally adjacent to a left-side of a lowermost-leftmost pixel in the target block, and
an y-coordinate of the second neighbor pixel is equal to an y-coordinate of the lowermost-leftmost pixel in the target block.
2 . The video decoding method of claim 1 , wherein:
one candidate of the list is generated based on prediction information of a plurality of neighbor blocks which are adjacent to the target block.
3 . The video decoding method of claim 2 , wherein the one candidate is an average of two prediction information of two neighbor blocks.
4 . The video decoding method of claim 2 , wherein the one candidate is generated based on prediction information of three neighbor blocks.
5 . 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.
6 . The video decoding method of claim 5 , wherein the refinement is performed using a Sum of Absolute Differences (SAD) between two reference blocks.
7 . A video encoding method, comprising:
deriving inter prediction information for a target block;
performing prediction for the target block using the inter prediction information; and
generating an indicator indicating a method to derive the inter prediction information,
wherein:
a list comprising a plurality of candidates is configured for the target block,
the prediction is performed using the list,
the plurality of candidates are generated by adding prediction information of a plurality of neighbor blocks which are adjacent to the target block to the list according to a specific order,
according to the specific order, prediction information of a first neighbor block is added to the list first, prediction information of a second neighbor block is added to the list second,
the first neighbor block is a block comprising a first neighbor pixel,
the first neighbor pixel is a pixel which is vertically adjacent to an upper-side of an uppermost-rightmost pixel in the target block,
an x-coordinate of the first neighbor pixel is equal to an x-coordinate of the uppermost-rightmost pixel in the target block,
the second neighbor block is a block comprising a second neighbor pixel,
the second neighbor pixel is a pixel which is horizontally adjacent to a left-side of a lowermost-leftmost pixel in the target block, and
an y-coordinate of the second neighbor pixel is equal to an y-coordinate of the lowermost-leftmost pixel in the target block.
8 . The video encoding method of claim 7 , wherein
a list comprising a plurality of candidates is configured for the target block, and a prediction is performed using the list for a decoding for the target block using the indicator,
the plurality of the candidates are generated based on a plurality of neighbor blocks which are adjacent to the target block, and
the plurality of the neighbor blocks includes 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.
9 . The video encoding method of claim 7 , wherein the one candidate is an average of two prediction information of two neighbor blocks.
10 . The video encoding method of claim 7 , wherein the one candidate is generated based on prediction information of three neighbor blocks.
11 . The video encoding method of claim 7 , 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.
12 . The video encoding method of claim 11 , wherein the refinement is performed using a Sum of Absolute Differences (SAD) between two reference blocks.
13 . A non-transitory computer-readable medium storing a bitstream generated by the video encoding method of claim 7 .
14 . A non-transitory computer-readable medium storing a bitstream generated by a processor performing an encoding method, the bitstream comprising:
inter prediction information for a target block,
the inter prediction information is used to perform prediction for the target block,
a list comprising a plurality of candidates is configured for the target block,
the list is used to perform the prediction,
the plurality of candidates are generated by adding prediction information of a plurality of neighbor blocks which are adjacent to the target block to the list according to a specific order,
according to the specific order, prediction information of a first neighbor block is added to the list first, prediction information of a second neighbor block is added to the list second,
the first neighbor block is a block comprising a first neighbor pixel,
the first neighbor pixel is a pixel which is vertically adjacent to an upper-side of an uppermost-rightmost pixel in the target block,
an x-coordinate of the first neighbor pixel is equal to an x-coordinate of the uppermost-rightmost pixel in the target block,
the second neighbor block is a block comprising a second neighbor pixel,
the second neighbor pixel is a pixel which is horizontally adjacent to a left-side of a lowermost-leftmost pixel in the target block, and
a y-coordinate of the second neighbor pixel is equal to a y-coordinate of the lowermost-leftmost pixel in the target block.
15 . A non-transitory computer-readable recording medium storing a bitstream generated by a video encoding apparatus performing a video encoding method, the video encoding method comprising:
deriving inter prediction information for a target block;
performing prediction for the target block using the inter prediction information; and
generating an indicator indicating a method to derive the inter prediction information, wherein
a list comprising a plurality of candidates is configured for the target block,
the prediction is performed using the list,
the plurality of candidates are generated by adding prediction information of a plurality of neighbor blocks which are adjacent to the target block to the list according to a specific order,
according to the specific order, prediction information of a first neighbor block is added to the list first, prediction information of a second neighbor block is added to the list second,
the first neighbor block is a block comprising a first neighbor pixel,
the first neighbor pixel is a pixel which is vertically adjacent to an upper-side of an uppermost-rightmost pixel in the target block,
an x-coordinate of the first neighbor pixel is equal to an x-coordinate of the uppermost-rightmost pixel in the target block,
the second neighbor block is a block comprising a second neighbor pixel,
the second neighbor pixel is a pixel which is horizontally adjacent to a left-side of a lowermost-leftmost pixel in the target block, and
a y-coordinate of the second neighbor pixel is equal to a y-coordinate of the lowermost-leftmost pixel in the target block.