Encoder and decoder and methods thereof

A method, performed by a decoder, for adaptive loop filtering, the method comprising:

• determining a first activity value for a first block in a picture frame, wherein the first block comprises a first plurality of pixels;
• determining a first quantization parameter (QP) value for the first block;
• calculating a weighted activity value using the first activity value and the first QP value as inputs to the calculation;
• selecting a filter from a plurality of filters based on the weighted activity value;
• and
• applying the selected filters to the first block.

An encoder for adaptive loop filtering, the encoder comprising:

• a processor, configured to:
• determine a first activity value for a first block in a frame or a slice, wherein the first block comprises a first plurality of pixels;
• determine a first quantization parameter (QP) value for the first block;
• calculate a weighted activity value using the first activity value and the first QP value as inputs to the calculation;
• select a filter from a plurality of filters based on the weighted activity value;
• and
• apply the selected filter to the first block.

A decoder for adaptive loop filtering, the decoder comprising:

• a processor, configured to:
• determine a first activity value for a first block in a picture frame, wherein the first block comprises a first plurality of pixels;
• determine a first quantization parameter (QP) value for the first block;
• calculating a weighted activity value using the first activity value and the first QP value as inputs to the calculation;
• select a filter from a plurality of filters based on the weighted activity value;
• and
• apply the selected filter to the first block.