Support of multiple chroma format in VVC

A method for encoding a video sequence, the method comprising:

• encoding the video sequence using one of a 4:4:4 chroma format and a 4:2:2 chroma format;
• when the video sequence is being encoded using the 4:4:4 chroma format, copying an affine motion vector of one 4×4 luma block using an operation other than an averaging operation and associating the affine motion vector to a co-located 4×4 chroma block, and
• when the video sequence is being encoded using the 4:2:2 chroma format;
• associating each 4×4 chroma block with two 4×4 co-located luma blocks such that an affine motion vector of one 4×4 chroma block is an average of the motion vectors of the two co-located luma blocks, wherein a maximum vertical transform size is the same among different color components, and wherein a maximum horizontal transform size for color components is half of a maximum horizontal transform size for luma components.

A method of processing visual media data, comprising:

• obtaining a visual media file;
• and
• performing a conversion between the visual media file and a bitstream of a visual media data, wherein the bitstream comprises an encoded video sequence with a 4:4:4 chroma format and a 4:2:2 chroma format, and wherein performing the conversion comprises:
• using, in the 4:4:4 chroma format, an affine motion vector copied from a 4×4 luma block via an operation other than an averaging operation for a co-located 4×4 chroma block, and
• using, in the 4:2:2 chroma format, an affine motion vector for a 4×4 chroma block that is an average of motion vectors of two co-located luma blocks, wherein a maximum vertical transform size is the same among different color components, and wherein a maximum horizontal transform size for color components is half of a maximum horizontal transform size for luma components.