Bilateral matching for compound reference mode

A computing system, comprising:

• control circuitry;
• and
• memory storing one or more programs configured to be executed by the control circuitry, the one or more programs further comprising instructions for:
• receiving a current coding block in a current image frame from a video bitstream;
• determining that the current coding block is to be predicted in a joint motion vector difference (JMVD) mode;
• in response to the current coding block being predicted in the JMVD mode, determining that the current coding block is associated with two bi-prediction blocks including a forward prediction block and a backward prediction block;
• based on a cost criterion of a difference of the forward prediction block and the backward prediction block, refining a motion vector difference for at least the forward prediction block to determine a first refined motion vector difference;
• generating the forward prediction block based on at least the first refined motion vector difference;
• and
• determining motion compensation data of the current coding block based on the forward prediction block and the backward prediction block.

A non-transitory computer-readable storage medium storing one or more programs for execution by control circuitry of a computing system, the one or more programs comprising instructions for:

• receiving a current coding block in a current image frame from a video bitstream;
• determining that the current coding block is to be predicted in a joint motion vector difference (JMVD) mode;
• in response to the current coding block being predicted in the JMVD mode, determining that the current coding block is associated with two bi-prediction blocks including a forward prediction block and a backward prediction block;
• based on a cost criterion of a difference of the forward prediction block and the backward prediction block, refining a motion vector difference for at least the forward prediction block to determine a first refined motion vector difference;
• generating the forward prediction block based on at least the first refined motion vector difference;
• and
• determining motion compensation data of the current coding block based on the forward prediction block and the backward prediction block.