Generating a motion vector predictor list

A decoder apparatus, comprising:

• a processor;
• and
• memory coupled with the processor, wherein the memory comprises instructions that when executed by the processor cause the decoder apparatus to perform operations, the operations comprising:
• obtaining a current inter block and a plurality of previously decoded inter blocks, each inter block of the plurality of inter blocks including a motion vector having a resolution;
• and
• generating a list of motion vector predictor candidates that is used to predict the motion vector that is associated with the current inter block, wherein generating the list of motion vector predictor candidates comprises:
• defining a set of inter blocks that includes a number of previously decoded inter blocks;
• scanning the inter blocks in the set of inter blocks in a scanning order;
• and
• for each of the inter blocks in the set of inter blocks:
• deriving a motion vector prediction candidate using the motion vector of the inter block;
• determining whether a criterion relating to one or both of the inter block and the current inter block is satisfied, wherein the criterion is satisfied responsive to the inter block being from a different picture than a picture that includes the current inter block and a resolution of the motion vector prediction candidate exceeding a resolution threshold;
• and
• either:
• responsive to determining that the criterion is satisfied, adding the motion vector prediction candidate to the list of motion vector prediction candidates without performing a motion vector comparison operation with existing motion vector prediction candidates that are in the list of motion vector prediction candidates corresponding to the current inter block;
• or
• responsive to determining that the criterion is not satisfied, performing the motion vector comparison operation to compare the motion vector prediction candidate with the existing motion vector prediction candidates that are in the list of motion vector prediction candidates corresponding to the current inter block.

A non-transitory computer-readable medium having instructions stored therein that are executable to perform operations comprising:

• obtaining a current inter block and a plurality of previously decoded inter blocks, each inter block of the plurality of inter blocks including a motion vector having a resolution;
• and
• generating a list of motion vector predictor candidates that is used to predict the motion vector that is associated with the current inter block, wherein generating the list of motion vector predictor candidates comprises:
• defining a set of inter blocks that includes a number of previously decoded inter blocks;
• scanning the inter blocks in the set of inter blocks in a scanning order;
• and
• for each of the inter blocks in the set of inter blocks:
• deriving a motion vector prediction candidate using the motion vector of the inter block;
• determining whether a criterion relating to one or both of the inter block and the current inter block is satisfied, wherein the criterion is satisfied responsive to the motion vector prediction candidate of the inter block being included in a history based motion vector prediction (“HMVP”) table and a resolution of the motion vector prediction candidate exceeding a resolution threshold;
• and
• either:
• responsive to determining that the criterion is satisfied, adding the motion vector prediction candidate to the list of motion vector prediction candidates without performing a motion vector comparison operation with existing motion vector prediction candidates that are in the list of motion vector prediction candidates corresponding to the current inter block;
• or
• responsive to determining that the criterion is not satisfied, performing the motion vector comparison operation to compare the motion vector prediction candidate with the existing motion vector prediction candidates that are in the list of motion vector prediction candidates corresponding to the current inter block.