Duplicate partitioning prevention

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 to enable a first partitioning scheme for a current video unit according to a rule;
• and
• perform a conversion between a video comprising the current video unit and a bitstream based on the determination;
• wherein the rule is based on a relationship between the current video unit and one or more ancestor video units from which the current video unit is split directly or indirectly;
• wherein the rule specifies that the one or more ancestor video units are checked iteratively,
• wherein a video unit B is set to be the current video unit, k is an integer and is set to be 0, a process comprising following steps A)˜D) is executed iteratively,
• step A):
• in a case that the video unit B is not a root block, checking a parent video unit P of the video unit B,
• step B):
• finding the parent video unit P of the video unit B, and setting the video unit B to be the parent video unit P,
• step C):
• setting k to be k+1, and
• step D):
• returning to step A),
• wherein the process is terminated when one or more conditions are satisfied, wherein the one or more conditions comprise at least one of:
• a width and/or a height of the video unit B being larger than and/or smaller than a threshold,
• a size of the video unit B being larger than and/or smaller than a first threshold,
• a ratio between the width and the height of the video unit B being larger than and/or smaller than a second threshold,
• a depth of the video unit B being larger than and/or smaller than a third threshold, and
• k being larger than or equal to a fourth threshold.

A method for storing bitstream of a video, comprising:

• determining whether to enable a first partitioning scheme for a current video unit of the video according to a rule;
• and
• generating the bitstream based on the determining;
• storing the bitstream in a non-transitory computer-readable recording medium;
• wherein the rule is based on a relationship between the current video unit and one or more ancestor video units from which the current video unit is split directly or indirectly;
• wherein the rule specifies that the one or more ancestor video units are checked iteratively,
• wherein a video unit B is set to be the current video unit, k is an integer and is set to be 0, a process comprising following steps A)˜D) is executed iteratively,
• step A):
• in a case that the video unit B is not a root block, checking a parent video unit P of the video unit B,
• step B):
• finding the parent video unit P of the video unit B, and setting the video unit B to be the parent video unit P,
• step C):
• setting k to be k+1, and
• step D):
• returning to step A),
• wherein the process is terminated when one or more conditions are satisfied, wherein the one or more conditions comprise at least one of:
• a width and/or a height of the video unit B being larger than and/or smaller than a threshold,
• a size of the video unit B being larger than and/or smaller than a first threshold,
• a ratio between the width and the height of the video unit B being larger than and/or smaller than a second threshold,
• a depth of the video unit B being larger than and/or smaller than a third threshold, and
• k being larger than or equal to a fourth threshold.