Usage of LUTs

An apparatus for processing video data comprising a processor and a non-transitory memory with instructions thereon, wherein the instructions upon execution by the processor, cause the processor to:

• maintain one or more tables of motion candidates during a conversion between a current video block and a bitstream of a video including the current video block, wherein each table comprises one or more motion candidates derived from one or more previous blocks;
• determine a coding mode of the current video block;
• construct a candidate list, wherein whether to use the one or more tables during constructing the candidate list is based on the coding mode of the current video block;
• and
• perform, based on the candidate list, the conversion between the current video block of and the bitstream,
• wherein the processor is configured to construct the candidate list:
• using the one or more tables based on the coding mode belonging to at least one first coding mode, and wherein the at least one first coding mode comprises a non-affine mode;
• or
• without using the one or more tables based on the coding mode belonging to at least one second coding mode, wherein the at least one second coding mode comprises an affine mode, and
• whether to update the one or more tables based on motion information derived from the candidate list is based on the coding mode of the current video block;
• wherein the one or more tables are updated based on the coding mode being the non-affine mode and the one or more tables are not updated based on the coding mode being the affine mode.

A non-transitory computer-readable storage medium storing instructions that cause a processor to:

• maintain one or more tables of motion candidates during a conversion between a current video block and a bitstream of a video including the current video block, wherein each table comprises one or more motion candidates derived from one or more previous blocks;
• determine a coding mode of the current video block;
• construct a candidate list, wherein whether to use the one or more tables during constructing the candidate list is based on the coding mode of the current video block;
• and
• perform, based on the candidate list, the conversion between the current video block of and the bitstream,
• wherein the candidate list is constructed by:
• using the one or more tables based on the coding mode belonging to at least one first coding mode, and wherein the at least one first coding mode comprises a non-affine mode;
• or
• without using the one or more tables based on the coding mode belonging to at least one second coding mode, wherein the at least one second coding mode comprises an affine mode, and
• whether to update the one or more tables based on motion information derived from the candidate list is based on the coding mode of the current video block;
• wherein the one or more tables are updated based on the coding mode being the non-affine mode and the one or more tables are not updated based on the coding mode being the affine mode.

A method for storing a bitstream, comprising:

• maintaining one or more tables of motion candidates during a conversion between a current video block and a bitstream of a video including the current video block, wherein each table comprises one or more motion candidates derived from one or more previous blocks;
• determining a coding mode of the current video block;
• constructing a candidate list, wherein whether to use the one or more tables during constructing the candidate list is based on the coding mode of the current video block;
• generating, based on the candidate list, the bitstream from the current video block;
• and
• storing the generated bitstream in a non-transitory computer-readable recording medium, wherein the candidate list is constructed by:
• using the one or more tables based on the coding mode belonging to at least one first coding mode, and wherein the at least one first coding mode comprises a non-affine mode;
• or
• without using the one or more tables based on the coding mode belonging to at least one second coding mode, wherein the at least one second coding mode comprises an affine mode, and
• whether to update the one or more tables based on motion information derived from the candidate list is based on the coding mode of the current video block;
• wherein the one or more tables are updated based on the coding mode being the non-affine mode and the one or more tables are not updated based on the coding mode being the affine mode.