SIGNALING USAGE OF ADAPTIVE LOOP FILTER IN VIDEO CODING

Methods, systems and devices for signaling the usage of adaptive loop filtering in image and video coding are described. An example method of video processing includes determining, for a conversion between a current region of a video and a bitstream representation of the video, whether a luma adaptive loop filter is used during the conversion and whether luma adaptive loop filter coefficients are included in the bitstream representation, wherein a single syntax element in the bitstream representation is indicative of use of the luma adaptive loop filter and signaling of the luma adaptive loop filter coefficients, and performing, based on the determining, the conversion.