Efficient use of storage in encoding and decoding video data streams

A non-transitory machine readable medium storing a computer program for identifying a partition configuration of a pixel group in a video picture, the computer program executable by at least one processing unit, the program comprising sets of instructions for:

• receiving the pixel group comprising a set of partitions, each partition comprising a plurality of pixels, the pixel group comprising information that identifies position and dimensions for each partition of the pixel group;
• identifying a partition configuration of the pixel group based on said information, wherein the partition configuration identifies how the pixel group is partitioned into a set of partitions from a plurality of unique candidate combinations of partitions, each unique candidate combination of partitions specifying a set of partitions, wherein no candidate combination of partitions specifies a set of partitions that is identical to a set of partitions specified by another candidate combination of partitions;
• specifying a partition configuration value for the pixel group, wherein the partition configuration value uniquely identifies the partition configuration of the pixel group as comprising a particular combination of partitions from the plurality of unique candidate combinations of partitions;
• and
• using the partition configuration value in conjunction with a partition configuration look up table to decode the pixel group,
• wherein each partition in a specified set has a position and dimensions relative to the pixel group, wherein two candidate combinations of partitions are not identical to each other when one candidate combination of partitions specifies a partition with at least one of a particular position and a particular dimension that the other candidate combination of partitions does not specify.