An apparatus configured to decode video data, including a memory configured to store a block of a current picture of the video data, and one or more processors in communication with the memory. The one or more processors may be configured to reconstruct the block of the current picture of the video data, determine a classification, from among a plurality of classifications, of the block according to a rule, wherein the rule is adaptively determined based on characteristics of coded sequences of the video data, and apply an adaptive loop filter (ALF) to the block based on the classification of the block.