On Tue Mar 18 18:32:59 2025 +0000, Connor McAdams wrote:
changed this line in [version 2 of the diff](/wine/wine/-/merge_requests/7577/diffs?diff_id=164932&start_sha=c592af0c989d202ae74fb9b140acef84db7e99be#00fcd0e0df705d939078be032416805331b596d0_567_580)
I probably spent way longer investigating this than I should have, but basically what I found was:
Native had a max diff of 5, we had a max diff of 40. Even setting the libjpeg encoder to the maximum quality didn't get us within the same max diff as native. I then also enabled smoothing, the best I could get was a max diff of 10.
For some reason I thought JPG blocks were 4x4, they're 8x8. I've updated the tests now to have the quadrants as 8x8 and now we're within a max diff of 1, which is the same as native. I feel like that "resolves" things, although it does seem like our JPEG encoding is inferior to native and I've only masked the issue. Not sure if anything would rely upon this, or if I should make a note of it somewhere.