A video decoder can be configured to determine first filter information for a first luma block unit of a current block; filter the first luma block unit based on the first filter information; determine second filter information for a second luma block unit of the current block; filter the second luma block unit based on the second filter information; and derive third filter information for a chroma block unit of the current block based on filter information determined for multiple luma block units, wherein the filter information determined for the multiple luma block units includes the first filter information for the first luma block unit and the second filter information for the second luma block unit; filter the chroma block unit based on the third filter information; and output a decoded version of the current block.