Threshold of similarity for candidate list

An electronic apparatus comprising:

• a video coder circuit configured to perform operations comprising:
• receiving data for a block of pixels to be encoded or decoded as a current block of a current picture of a video;
• generating a list of candidate prediction vectors for the current block;
• pruning the list of candidate prediction vectors by removing a first prediction vector that is within a threshold of a second prediction vector from the list, wherein the threshold has a first value when refinement is enabled and a second value when refinement is not enabled;
• selecting a candidate prediction vector from the pruned list of candidate prediction vectors;
• when refinement is enabled:
• refining the selected prediction vector;
• and
• encoding or decoding the current block by using the refined prediction vector to reconstruct the current block;
• and
• when refinement is not enabled:
• encoding or decoding the current block by using the selected prediction vector to reconstruct the current block.

A video decoding method comprising:

• receiving data for a block of pixels to be decoded as a current block of a current picture of a video;
• generating a list of candidate prediction vectors for the current block;
• pruning the list of candidate prediction vectors by removing a first prediction vector that is within a threshold of a second prediction vector from the list, wherein the threshold has a first value when refinement is enabled and a second value when refinement is not enabled;
• selecting a candidate prediction vector from the pruned list of candidate prediction vectors;
• when refinement is enabled:
• refining the selected prediction vector;
• and
• reconstructing the current block by using the refined prediction vector to generate a prediction block;
• and
• when refinement is not enabled:
• reconstructing the current block by using the selected prediction vector to generate a prediction block.

A video encoding method comprising:

• receiving data for a block of pixels to be encoded as a current block of a current picture of a video;
• generating a list of candidate prediction vectors for the current block;
• pruning the list of candidate prediction vectors by removing a first prediction vector that is within a threshold of a second prediction vector from the list, wherein the threshold has a first value when refinement is enabled and a second value when refinement is not enabled;
• selecting a candidate prediction vector from the pruned list of candidate prediction vectors;
• when refinement is enabled:
• refining the selected prediction vector;
• and
• encoding the current block by using the refined prediction vector to generate a prediction block;
• and
• when refinement is not enabled:
• encoding the current block by using the selected prediction vector to generate a prediction block.