Method for performing local motion vector derivation during video coding of a coding unit, and associated apparatus

An apparatus for performing local motion vector derivation during video coding of a coding unit, the apparatus comprising:

• a processing circuit arranged to perform video coding on the coding unit, wherein the processing circuit comprises:
• a preprocessing module arranged to process a plurality of sub-coding units in the coding unit and perform motion vector prediction of each sub-coding unit of the coding unit, wherein the preprocessing module derives a motion vector of a specific sub-coding unit of the sub-coding units by utilizing at least one motion vector of at least one other sub-coding/coding unit and performs motion compensation on the specific sub-coding unit according to the motion vector of the specific sub-coding unit, wherein the preprocessing module derives a motion vector of another sub-coding unit in the coding unit by utilizing at least one motion vector that is different from the motion vector utilized for deriving the motion vector of the specific sub-coding unit;
• and
• at least one coding module arranged to perform video coding on the coding unit based on the motion compensation performed by the preprocessing module.

A method for performing local motion vector derivation during video coding of a coding unit, the method comprising:

• receiving the coding unit comprising a plurality of sub-coding units;
• parsing data of the coding unit;
• and
• designating a reference motion vector of a specific sub-coding unit of the coding unit according to a predetermined rule, wherein the reference motion vector is utilized for reference by at least one other sub-coding unit/coding unit, and is not utilized for motion vector prediction of the specific sub-coding unit.