Method and apparatus for Adaptive Loop Filter with tap constraints for video coding

Method and apparatus for video coding using. According to one method, a current filtered output is derived from an ALF for a current sample in the current block. The current filtered output is derived from an ALF for a current sample, where the ALF comprises an input term associated with one or more neighbouring fixed-filtered samples, and the neighbouring fixed-filtered samples are from a restricted area with respect to the current sample. According to another method, the ALF comprises an input term associated with a modification term corresponding to an output by filtering clipped neighbouring difference values using filter coefficients of fixed filter sets, where the neighbouring difference values are determined between neighbouring samples and a to-be-processed sample.