Method for constructing merge candidate motion information list, apparatus, and codec

A method for constructing a merge candidate motion information list, comprising:

• obtaining a first candidate motion information set, wherein the first candidate motion information set comprises motion information of a spatially neighboring block of a current block and/or motion information of a temporally neighboring block of the current block;
• when a quantity of pieces of motion information in the first candidate motion information set is less than a preset threshold, obtaining first motion information;
• when the first motion information is different from the motion information in the first candidate motion information set, adding the first motion information to the first candidate motion information set, to obtain a second candidate motion information set;
• when a quantity of pieces of motion information in the second candidate motion information set is less than the preset threshold, obtaining a history-based motion vector prediction (HMVP) candidate motion information list, and obtaining second motion information based on motion information in the HMVP candidate motion information list;
• when the second motion information is different from the motion information in the second candidate motion information set, adding the second motion information to the second candidate motion information set, to obtain a third candidate motion information set;
• and
• when a quantity of pieces of motion information in the third candidate motion information set is equal to the preset threshold, using the third candidate motion information set as the merge candidate motion information list.

A non-transitory computer-readable storage medium that stores a computer program, which when executed by a processor, causes the processor to perform operations of:

• obtaining a first candidate motion information set, wherein the first candidate motion information set comprises motion information of a spatially neighboring block of a current block and/or motion information of a temporally neighboring block of the current block;
• when a quantity of pieces of motion information in the first candidate motion information set is less than a preset threshold, obtaining first motion information;
• when the first motion information is different from the motion information in the first candidate motion information set, adding the first motion information to the first candidate motion information set, to obtain a second candidate motion information set;
• when a quantity of pieces of motion information in the second candidate motion information set is less than the preset threshold, obtaining a history-based motion vector prediction (HMVP) candidate motion information list, and obtaining second motion information based on motion information in the HMVP candidate motion information list;
• when the second motion information is different from the motion information in the second candidate motion information set, adding the second motion information to the second candidate motion information set, to obtain a third candidate motion information set;
• and
• when a quantity of pieces of motion information in the third candidate motion information set is equal to the preset threshold, using the third candidate motion information set as a merge candidate motion information list.