Matteo Bruni (@Mystral) commented about dlls/d3dx9_36/tests/texture.c:
+ ok(hr == D3D_OK, "Unexpected hr %#lx.\n", hr); + + hr = D3DXLoadSurfaceFromFileInMemory(surface, NULL, NULL, ID3DXBuffer_GetBufferPointer(buffer), + ID3DXBuffer_GetBufferSize(buffer), NULL, D3DX_FILTER_NONE, 0, NULL); + ok(hr == D3D_OK, "Unexpected hr %#lx.\n", hr); + + IDirect3DSurface9_Release(surface); + ID3DXBuffer_Release(buffer); + + /* + * Wine's JPEG compression quality is worse than native. Native uses 4:2:0 + * subsampling which is the same as what we use, but whatever compression + * settings they're using results in a JPEG image that is much closer to + * the original uncompressed surface. This is most apparent in 16x16 + * blocks with multiple colors. + */ Ah, so it wasn't chroma subsampling after all? :rolling_eyes:
Did you see that from the JPEG metadata or just deduce it from the test results? -- https://gitlab.winehq.org/wine/wine/-/merge_requests/7636#note_98840