Prediction weighted table-based image/video coding method and apparatus

A video encoding method performed by a video encoding apparatus, the method comprising:

• deriving motion information of a current block;
• generating prediction samples by performing weighted prediction on the current block based on the motion information;
• encoding image information comprising a flag related to the weighted prediction and a prediction weighted table syntax;
• and
• generating a bitstream by encoding the image information,
• wherein the prediction weighted table syntax is related to luma and chroma weighting factors for the weighted prediction,
• wherein the flag related to the weighted prediction is signaled in a picture header or a picture parameter set level, and the flag related to the weighted prediction represents whether the prediction weighted table syntax is present in the picture header or a slice header,
• wherein a value of the flag is determined as 1 based on the prediction weighted table syntax being comprised in the picture header of the image information, and
• wherein the value of the flag is determined as 0 based on the prediction weighted table syntax being comprised in the slice header of the image information.

A transmission method of data for a video, the method comprising:

• obtaining a bitstream for the video, wherein the bitstream is generated based on deriving motion information of a current block, generating prediction samples by performing weighted prediction on the current block based on the motion information, encoding image information comprising a flag related to the weighted prediction and a prediction weighted table syntax, and generating the bitstream by encoding the image information;
• and
• transmitting the data comprising the bitstream,
• wherein the prediction weighted table syntax is related to luma and chroma weighting factors for the weighted prediction,
• wherein the flag related to the weighted prediction is signaled in a picture header or a picture parameter set level, and the flag related to the weighted prediction represents whether the prediction weighted table syntax is present in the picture header or a slice header,
• wherein a value of the flag is determined as 1 based on the prediction weighted table syntax being comprised in the picture header of the image information, and
• wherein the value of the flag is determined as 0 based on the prediction weighted table syntax being comprised in the slice header of the image information.