Device and method for coding video data

An electronic device for decoding a bitstream, the electronic device comprising:

• at least one processor;
• and
• a storage device coupled to the at least one processor and storing a plurality of instructions which, when executed by the at least one processor, causes the at least one processor to:
• receive an image frame of the bitstream;
• determine a block unit from the received image frame;
• receive first motion information and second motion information from a candidate list to reconstruct the block unit, wherein the first motion information includes a first list flag for selecting a first reference frame and the second motion information includes a second list flag for selecting a second reference frame;
• determine a sub-block in the block unit;
• compare the first list flag with the second list flag;
• store a predefined one of the first motion information and the second motion information as the stored motion information for the sub-block without checking whether the first reference frame and the second reference frame are included in a specific one of a plurality of reference lists indicated by a specific one of a plurality of flag values different from the first list flag and the second list flag when the first list flag is identical to the second list flag;
• and
• reconstruct a following block based on the stored motion information when the following block is reconstructed based on the sub-block.

A method of decoding a bitstream by an electronic device, the method comprising:

• receiving an image frame of the bitstream;
• determining a block unit from the received image frame;
• determining a split line of the block unit;
• receiving first motion information and second motion information from a candidate list to reconstruct the block unit, wherein the first motion information includes a first list flag and the second motion information includes a second list flag;
• determining a sub-block in the block unit;
• determining whether the sub-block is included in a specific one of a plurality of block regions separated based on the split line, wherein the specific one of the plurality of block regions covers the split line;
• determining, based only on a comparison between the first list flag and the second list flag, whether the first motion information and the second motion information are stored together as the stored motion information for the sub-block, when the sub-block is included in the specific one of the plurality of block regions;
• and
• reconstructing a following block based on the stored motion information when the following block is reconstructed based on the sub-block.