@flancian someone prototyped the idea for a chinese codec. the strategy works quite well it seems.

one of the bigger problems of av1 and h265 is that there are SO MANY filter combinations. that's why they can crush the bits per pixel so low, but it takes forever to find a filter stack that works.

as far as i know most work has been on trying to speed up the underlying filters more than trying to predict the filter stack directly