Interaction between lut and shared merge list

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:

• determine whether a sharing of merge list information is enabled for a merge sharing node that corresponds to an ancestor node in a coding unit split tree to allow leaf coding units of the ancestor node in the coding unit split tree to use the merge list information;
• and
• perform a conversion between a current video block of a video and a bitstream of the video based on the determining,
• wherein updating a motion candidate table is selectively enabled or disabled during the conversion, and wherein a single representative coded block is selected to update the motion candidate table:
• wherein the single representative coded block is selected as a last coded block that satisfies a first condition for updating the motion candidate table, wherein the first condition for updating the motion candidate table requires that the last coded block is coded with a non-affine and non-ATMVP (alternative temporal motion vector prediction) inter mode, wherein an ATMVP mode modifies motion vectors temporal motion vector prediction (TMVP) by fetching multiple sets of motion information from blocks smaller than a current coding unit including the current video block, or
• wherein the single representative coded block is selected as a first coded block that satisfies a second condition for updating the motion candidate table, wherein the second condition for updating the motion candidate table requires that the first coded block is coded with a non-affine and non-ATMVP inter mode.

A non-transitory computer-readable recording medium storing a bitstream which is generated by a method performed by a video processing apparatus, wherein the method comprises:

• determining whether a sharing of merge list information is enabled for a merge sharing node that corresponds to an ancestor node in a coding unit split tree to allow leaf coding units of the ancestor node in the coding unit split tree to use the merge list information;
• and
• generating the bitstream based on the determining,
• wherein updating a motion candidate table is selectively enabled or disabled during the generating, and wherein a single representative coded block is selected to update the motion candidate table:
• wherein the single representative coded block is selected as a last coded block that satisfies a first condition for updating the motion candidate table, wherein the first condition for updating the motion candidate table requires that the last coded block is coded with a non-affine and non-ATMVP (alternative temporal motion vector prediction) inter mode, wherein an ATMVP mode modifies motion vectors temporal motion vector prediction (TMVP) by fetching multiple sets of motion information from blocks smaller than a current coding unit including the current video block, or
• wherein the single representative coded block is selected as a first coded block that satisfies a second condition for updating the motion candidate table, wherein the second condition for updating the motion candidate table requires that the first coded block is coded with a non-affine and non-ATMVP inter mode.