Method, device, and system for determining prediction weight for merge mode
Systems, devices, and methods for determining prediction weight for sub-block are provided. One exemplary method includes: partitioning a coding unit into a plurality of sub-blocks; determining a weight of a sub-block of the plurality of sub-blocks based on weights of control points, wherein the control points are neighboring corners of the coding unit; and bi-predicting the sub-block based on the determined weight.
1. A method for processing video data, the method comprising:
partitioning a coding unit into a plurality of sub-blocks, wherein the coding unit is associated with a first weight;
determining a second weight of a sub-block of the plurality of sub-blocks based on weights of control points, wherein the control points are neighboring corners of the coding unit; and
bi-predicting the sub-block based on the second weight.
2. The method according to claim 1 , wherein the determining the second weight of the sub-block within the coding unit comprises:
in response to the sub-block comprising one of the control points, using a weight of the one of the control points as the second weight of the sub-block, or in response to the sub-block not comprising the control points, determining the second weight of the sub-block according to a pre-defined rule.
3. The method according to claim 1 , wherein:
the coding unit is partitioned into four sub-blocks and has two control points; and
the determining the second weight of the sub-block within the coding unit comprises:
in response to the sub-block comprising one of the two control points, using a weight of the one of the two control points as the second weight of the sub-block, or
in response to the sub-block not comprising the two control points, setting the second weight of the sub-block to be one of:
a weight of one of the two control points with a shorter distance to the sub-block, or
a default value.
4. The method according to claim 1 , wherein:
the coding unit is partitioned into two sub-blocks and has three control points; and
the determining the second weight of the sub-block within the coding unit comprises:
in response to the sub-block including only one of the three control points, using a weight of the one of the control points as the second weight of the sub-block, or
in response to the sub-block comprising at least two of the three control points, using a default value or a weight of one of the two control points as the second weight of the sub-block.
5. The method according to claim 1 , wherein:
the coding unit is partitioned into four sub-blocks and has three control points, the three control points having a first control point weight, a second control point weight, and a third control point weight, respectively; and
the determining the second weight of the sub-block within the coding unit comprises:
in response to the sub-block comprising at least one of the three control points, using a weight of the one of the control points as the second weight of the sub-block, or
in response to the sub-block not comprising the three control points, setting the second weight of the sub-block to be one of:
an average value of the first control point weight, the second control point weight, and the third control point weight,
a middle value of the first control point weight, the second control point weight, and the third control point weight,
an equal weight of the coding unit,
one of the first control point weight, the second control point weight, and the third control point weight which has a smallest difference from the equal weight,
one of the first control point weight and second control point weight which has a smaller difference from the equal weight, or
a default value.
6. The method according to claim 1 , wherein the coding unit has two control points, and
the partitioning a coding unit into a plurality of sub-blocks comprises:
partitioning the coding unit into two sub-blocks, wherein each sub-block includes one control point; and
the determining the second weight of the sub-block of the plurality of sub-blocks based on weights of control points comprises:
using a weight of the control point included in the sub-block as the second weight of the sub-block.
7. The method according to claim 1 , wherein the coding unit has four control points, and
the partitioning a coding unit into a plurality of sub-blocks comprises:
partitioning the coding unit into four sub-blocks, wherein each sub-block includes one control point;
the determining the second weight of the sub-block of the plurality of sub-blocks based on weights of control points comprises:
using a weight of the control point included in the sub-block as the second weight of the sub-block.
8. A video processing apparatus, comprising:
a memory storing instructions; and
one or more processors configured to execute the instructions to cause the apparatus to perform:
partitioning a coding unit into a plurality of sub-blocks, wherein the coding unit is associated with a first weight;
determining a second weight of a sub-block of the plurality of sub-blocks based on weights of control points, respectively, wherein the control points are neighboring corners of the coding unit; and
bi-predicting the sub-block based on the second weight.
9. The apparatus according to claim 8 , wherein in determining the second weight of the sub-block within the coding unit, the one or more processors are further configured to execute the instructions to cause the apparatus to perform:
in response to the sub-block comprising one of the control points, using a weight of the one of the control points as the second weight of the sub-block, or
in response to the sub-block not comprising the control points, determining the second weight of the sub-block according to a pre-defined rule.
10. The apparatus according to claim 8 , wherein:
the coding unit is partitioned into four sub-blocks and has two control points; and
in determining the second weight of the sub-block within the coding unit, the one or more processors are further configured to execute the instructions to cause the apparatus to perform:
in response to the sub-block comprising one of the two control points, using a weight of the one of the two control points as the second weight of the sub-block, or
in response to the sub-block not comprising the two control points, setting the second weight of the sub-block to be one of:
a weight of one of the two control points with a shorter distance to the sub-block, or
a default value.
11. The apparatus according to claim 8 , wherein:
the coding unit is partitioned into two sub-blocks and has three control points; and
in determining the second weight of the sub-block within the coding unit, the one or more processors are further configured to execute the instructions to cause the apparatus to perform:
in response to the sub-block including only one of the three control points, using a weight of the one of the control points as the second weight of the sub-block, or
in response to the sub-block comprising at least two of the three control points, using a default value or a weight of one of the two control points as the second weight of the sub-block.
12. The apparatus according to claim 8 , wherein:
the coding unit is partitioned into four sub-blocks and has three control points, the three control points having a first control point weight, a second control point weight, and a third control point weight, respectively; and
in determining the second weight of the sub-block within the coding unit, the one or more processors are further configured to execute the instructions to cause the apparatus to perform:
in response to the sub-block comprising at least one of the three control points, using a weight of the one of the control points as the second weight of the sub-block, or
in response to the sub-block not comprising the three control points, setting the second weight of the sub-block to be one of:
an average value of the first control point weight, the second control point weight, and the third control point weight,
a middle value of the first control point weight, the second control point weight, and the third control point weight,
an equal weight of the coding unit,
one of the first control point weight, the second control point weight, and the third control point weight which has a smallest difference from the equal weight,
one of the first control point weight and the second control point weight which has a smaller difference from the equal weight, or
a default value.
13. The apparatus according to claim 8 , wherein:
the coding unit has two control points; and
in partitioning a coding unit into a plurality of sub-blocks, the one or more processors are further configured to execute the instructions to cause the apparatus to perform:
partitioning the coding unit into two sub-blocks, wherein each sub-block includes one control point; and
in determining the second weight of the sub-block of the plurality of sub-blocks based on weights of control points, the one or more processors are further configured to execute the instructions to cause the apparatus to perform:
using a weight of the control point included in the sub-block as the second weight of the sub-block.
14. The apparatus according to claim 8 , wherein:
the coding unit has four control points; and
in partitioning a coding unit into a plurality of sub-blocks, the one or more processors are further configured to execute the instructions to cause the apparatus to perform:
partitioning the coding unit into four sub-blocks, wherein each sub-block includes one control point; and
in determining the second weight of the sub-block of the plurality of sub-blocks based on weights of control points, the one or more processors are further configured to execute the instructions to cause the apparatus to perform:
using a weight of the control point included in the sub-block as the second weight of the sub-block.
15. A non-transitory computer readable medium storing a bitstream, wherein the bitstream comprises a flag indicating a coding unit being partitioned into a plurality of sub-blocks, wherein the flag causes a decoder to:
determine a second weight of a sub-block of the plurality of sub-blocks based on weights of control points, respectively, wherein the control points are neighboring corners of the coding unit; and
bi-predict the sub-block based on the second weight.
16. The non-transitory computer readable medium according to claim 15 , wherein the flag further indicates the coding unit being partitioned into four sub-blocks and having two control points, and the flag further causes the decoder to:
in response to the sub-block comprising one of the two control points, use a weight of the one of the two control points as the second weight of the sub-block, or
in response to the sub-block not comprising the two control points, set the second weight of the sub-block to be one of:
a weight of one of the two control points with a shorter distance to the sub-block, or
a default value.
17. The non-transitory computer readable medium according to claim 15 , wherein the flag further indicates the coding unit being partitioned into two sub-blocks and having three control points, and the flag further causes the decoder to:
in response to the sub-block including only one of the three control points, use a weight of the one of the control points as the second weight of the sub-block, or
in response to the sub-block comprising at least two of the three control points, use a default value or a weight of one of the two control points as the second weight of the sub-block.
18. The non-transitory computer readable medium according to claim 15 , wherein the flag further indicates the coding unit being partitioned into four sub-blocks and having three control points, the three control points having a first control point weight, a second control point weight, and a third control point weight, respectively, and the flag further causes the decoder to:
in response to the sub-block comprising at least one of the three control points, use a weight of the one of the control points as the second weight of the sub-block, or
in response to the sub-block not comprising the three control points, set the second weight of the sub-block to be one of:
an average value of the first control point weight, the second control point weight, and the third control point weight,
a middle value of the first control point weight, the second control point weight, and the third control point weight,
an equal weight of the coding unit,
one of the first control point weight, the second control point weight, and the third control point weight which has a smallest difference from the equal weight,
one of the first control point weight and the second control point weight which has a smaller difference from the equal weight, or
a default value.
19. The non-transitory computer readable medium according to claim 15 , wherein the flag further indicates the coding unit having two control points and the coding unit being partitioned into two sub-blocks, each sub-block including one control point, and the flag further causes the decoder to:
use a weight of the control point included in the sub-block as the second weight of the sub-block.
20. The non-transitory computer readable medium according to claim 15 , wherein the flag further indicates the coding unit having four control points and the coding unit being partitioned into four sub-blocks, each sub-block including one control point, and the flag further causes the decoder to:
use a weight of the control point included in the sub-block as the second weight of the sub-block.