Low latency local illumination compensation

An apparatus, comprising a processing circuitry configured to:

• decode prediction information for a plurality of first blocks in a current coded picture that is a part of a coded video sequence, the prediction information indicating that the plurality of first blocks are coded in a local illumination compensation (LIC) mode;
• select a neighboring region for each of the plurality of first blocks;
• determine a plurality of second blocks, each of the second blocks including one of the first blocks and the selected neighboring region of the one of the first blocks;
• for each of the plurality of second blocks, read a reference block corresponding to the one of the first blocks and a reference neighboring region of the reference block corresponding to the selected neighboring region of the one of the first blocks in a single access of a memory;
• perform an inter prediction for each of the plurality of second blocks in parallel with each other based on the read reference block and read reference neighboring region from the single access;
• determine a set of LIC parameters for each of the plurality of first blocks based on the read reference neighboring region from the single access;
• and
• reconstruct the plurality of first blocks based on the sets of LIC parameters.

A non-transitory computer-readable storage medium storing a program executable by at least one processor to perform:

• decoding prediction information for a plurality of first blocks in a current coded picture that is a part of a coded video sequence, the prediction information indicating that the plurality of first blocks are coded in a local illumination compensation (LIC) mode;
• selecting a neighboring region for each of the plurality of first blocks;
• determining a plurality of second blocks, each of the second blocks including one of the first blocks and the selected neighboring region of the one of the first blocks;
• for each of the plurality of second blocks, reading a reference block corresponding to the one of the first blocks and a reference neighboring region of the reference block corresponding to the selected neighboring region of the one of the first blocks in a single access of a memory;
• performing an inter prediction for each of the plurality of second blocks in parallel with each other based on the read reference block and read reference neighboring region from the single access;
• determining a set of LIC parameters for each of the plurality of first blocks based on the read reference neighboring region from the single access;
• and
• reconstructing the plurality of first blocks based on the sets of LIC parameters.