Method, device, and system for determining prediction weight for merge mode

1. A method for processing video data, the method comprising:

calculating a weight for a constructed affine merge candidate of a coding unit based on one or more weights associated with one or more control points neighboring the constructed affine merge candidate; and

bi-predicting the coding unit based on the calculated weight, wherein bi-predicting the coding unit based on the calculated weight comprises processing the video data using an affine merge mode, and the method further comprises:

determining, when constructing an affine merge candidate list, an order of a plurality of constructed affine merge candidates based on weights of control points corresponding to each of the plurality of constructed affine merge candidates, wherein

a constructed affine merge candidate having control points with less diverse weights is assigned a higher priority than a constructed affine merge candidate having control points with more diverse weights.

2. The method according to claim 1 , wherein the weight is calculated based on a weight index signaled in a bitstream.

3. The method according to claim 1 , further comprising:

in response to a plurality of control points associated with the constructed affine merge candidate having a same weight, determining the weight of the plurality of control points as a weight of the constructed affine merge candidate; or

in response to the plurality of control points having different weights, determining a default value as the weight of the constructed affine merge candidate.

4. The method according to claim 1 , further comprising:

determining, among weights of a plurality of control points corresponding to the constructed affine merge candidate, a weight used by most of the plurality of control points; and

setting the determined weight as the weight of the constructed affine merge candidate.

5. The method according to claim 1 , further comprising:

determining differences between an equal weight and weights of the one or more control points, respectively;

determining, among the one or more control points, a first control point with a weight having a smallest difference from the equal weight; and

setting the weight of the first control point as the weight of the constructed affine merge candidate.

6. The method according to claim 1 , further comprising:

calculating an average weight for a plurality of control points corresponding to the constructed affine merge candidate; and

setting the average weight as the weight of the constructed affine merge candidate.

7. The method according to claim 1 , wherein the bi-predicting the coding unit based on the calculated weight comprises processing the video data using the affine merge mode, and the method further comprises:

inserting, when constructing an affine merge candidate list, a zero motion vector with equal weight into the affine merge candidate list before inserting a zero motion vector with unequal weight.

8. The method of claim 1 , wherein the determining the order of the plurality of constructed affine merge candidates comprises:

in response to weights of control points corresponding to each of two constructed merge candidates having a same level of diversity, using a default order for the two constructed merge candidates.

9. The method of claim 1 , further comprising:

determining an availability of a first constructed affine merge candidate based on weights of control points corresponding to the first constructed affine merge candidate; and

in response to a determination that the first constructed affine merge candidate is available, adding the first constructed affine merge candidate to the affine merge candidate list.

10. The method of claim 9 , wherein the determining the availability of the first constructed affine merge candidate comprises:

determining whether weights of two control points corresponding to the first constructed affine merge candidate have different signs; and

in response to a determination that the weights of the two control points corresponding to the first constructed affine merge candidate have different signs, determining that the first constructed affine merge candidate is not available.

11. A video processing apparatus, comprising:

a memory storing instructions; and

a processor configured to execute the instructions to cause the device to:

calculating a weight for a constructed affine merge candidate of a coding unit based on one or more weights associated with one or more control points neighboring the constructed affine merge candidate;

bi-predicting the coding unit based on the calculated weight, wherein bi-predicting the coding unit based on the calculated weight comprises processing the video data using an affine merge mode; and

determining, when constructing an affine merge candidate list, an order of a plurality of constructed affine merge candidates based on weights of control points corresponding to each of the plurality of constructed affine merge candidates, wherein a constructed affine merge candidate having control points with less diverse weights is assigned a higher priority than a constructed affine merge candidate having control points with more diverse weights.

12. A non-transitory computer-readable medium storing a set of instructions that is executable by one or more processors of a video processing device to cause the device to perform a method comprising:

calculating a weight for a constructed affine merge candidate of a coding unit based on one or more weights associated with one or more control points neighboring the constructed affine merge candidate; and

bi-predicting the coding unit based on the calculated weight, wherein bi-predicting the coding unit based on the calculated weight comprises processing the video data using an affine merge mode, and the method further comprises:

determining, when constructing an affine merge candidate list, an order of a plurality of constructed affine merge candidates based on weights of control points corresponding to each of the plurality of constructed affine merge candidates, wherein

a constructed affine merge candidate having control points with less diverse weights is assigned a higher priority than a constructed affine merge candidate having control points with more diverse weights.

13. The method according to claim 1 , wherein calculating the weight for the constructed affine merge candidate further comprises:

calculating the weight for the constructed affine merge candidate based on a weight associated with a top left control point neighboring the constructed affine merge candidate or a weight associated with a top right control point neighboring the constructed affine merge candidate.