Multiple lists for block based weighting factors

A computing system comprising:

• control circuitry;
• and
• memory coupled to the control circuitry, the memory storing one or more sets of instructions configured to be executed by the control circuitry, the one or more sets of instructions including instructions for:
• obtaining video data comprising a plurality of frames of video data including a current block of a current frame;
• when the current block is to be predicted using compound inter prediction with a first reference frame and a second reference frame, determining whether the first reference frame and the second reference frame are on a same side of the current frame in display order;
• selecting a weighting factor list from among a plurality of weighting factor lists based on whether the first reference frame and the second reference frame are on the same side, wherein:
• a first weighting factor list of the plurality of weighting factor lists is associated with the first reference frame and the second reference frame being on the same side,
• a second weighting factor list of the plurality of weighting factor lists is associated with the first reference frame and the second reference frame being on different sides, and
• the first weighting factor list includes at least one weighting factor that is different from any weighting factor in the second weighting factor list;
• identifying a weighting factor from the selected weighting factor list;
• and
• encoding the current block by combining a first prediction block from the first reference frame and a second prediction block from the second reference frame using the identified weighting factor.

A non-transitory computer-readable storage medium storing one or more instructions that, when executed by a processor, cause a computing system to perform a video bitstream method comprising:

• when a current block of video data is to be predicted using compound inter prediction with a first reference frame and a second reference frame, determining whether the first reference frame and the second reference frame are on a same side of the current frame in display order;
• selecting a weighting factor list from among a plurality of weighting factor lists based on whether the first reference frame and the second reference frame are on the same side, wherein:
• a first weighting factor list of the plurality of weighting factor lists is associated with the first reference frame and the second reference frame being on the same side,
• a second weighting factor list of the plurality of weighting factor lists is associated with the first reference frame and the second reference frame being on different sides, and
• the first weighting factor list includes at least one weighting factor that is different from any weighting factor in the second weighting factor list;
• identifying a weighting factor from the selected weighting factor list;
• encoding the current block by combining a first prediction block from the first reference frame and a second prediction block from the second reference frame using the identified weighting factor;
• and
• transmitting a video bitstream that includes encoded information for the encoded current block.