Conditional application of refinement technique

A method for video encoding in an encoder, the method comprising:

• determining a current block in a current picture is to be encoded with an inter prediction mode with a potential usage of a refinement technique based on a first reference picture and a second reference picture;
• disabling, by a processor, the refinement technique in an encoding of a sample in the current block when a first equal weighting condition of chroma components from the first reference picture and the second reference picture is not satisfied;
• and
• encoding a first flag of a chroma weight of the first reference picture and a second flag of a chroma weight of the second reference picture in a bitstream, the first equal weighting condition being indicated as satisfied when the first flag of the chroma weight of the first reference picture is equal to a first predetermined value, and the second flag of the chroma weight of the second reference picture is equal to a second predetermined value.

A non-transitory computer-readable storage medium storing instructions which, when executed by a processor, cause the processor to perform a method of encoding a bitstream comprising:

• determining a current block in a current picture is to be encoded with an inter prediction mode with a potential usage of a refinement technique based on a first reference picture and a second reference picture;
• disabling the refinement technique in an encoding of a sample in the current block when a first equal weighting condition of chroma components from the first reference picture and the second reference picture is not satisfied;
• encoding a first flag of a chroma weight of the first reference picture and a second flag of a chroma weight of the second reference picture in the bitstream, the first equal weighting condition being indicated as satisfied when the first flag of the chroma weight of the first reference picture is equal to a first predetermined value, and the second flag of the chroma weight of the second reference picture is equal to a second predetermined value;
• and
• transmitting the encoded bitstream.