Video encoding method and apparatus, and video decoding method and apparatus for preventing small-sized intra block

A video decoding apparatus comprising:

• a luma block decoder configured to:
• obtain a width of a picture based on information about the width of the picture that is obtained from a bitstream;
• obtain a height of the picture based on information about the height of the picture that is obtained from the bitstream;
• and decode the luma block, when an x coordinate according to a luma width of a current block generated from the picture is not greater than the width of the picture, a y coordinate according to a luma height of the current block is not greater than the height of the picture, and a split mode of a luma block of the current block is a non-split mode;
• and
• a chroma block decoder configured to decode a chroma block corresponding to the luma block,
• wherein the information about the width of the picture indicates a number of luma samples arranged in a width direction of the picture, the number of luma samples arranged in the width direction is an integer multiple of 8, the information about the height of the picture indicates a number of luma samples arranged in a height direction of the picture, and the number of luma samples arranged in the height direction is an integer multiple of 8.

A video encoding method comprising:

• generating information about a width of a picture indicating a number of luma samples arranged in a width direction of the picture and information about a height of the picture indicating a number of luma samples arranged in a height direction of the picture;
• when an x coordinate according to a luma width of a current block generated from the picture is not greater than the width of the picture, a y coordinate according to a luma height of the current block is not greater than the height of the picture, and a split mode of a luma block of the current block is a non-split mode, encoding the luma block;
• and
• determining a chroma block corresponding to the luma block and encoding the chroma block,
• wherein the number of luma samples arranged in the width direction of the picture is an integer multiple of 8, and
• the number of luma samples arranged in the height direction of the picture is an integer multiple of 8.