I tried the latest patch:
1) with the unmodified patch the banding is fixed, however there are some areas (where there is the colour transition) where the colour is not uniform (like if there were some random noise overlapped);
2) with the uncommented
//lvtma_bit_depth_control &= ~AVIVO_LVTMA_BIT_DEPTH_CONTROL_SPATIAL_DITHER_EN;
the problem is also greatly fixed (I can see very little visible banding looking closer, but I think this is how the image is really) without the noise overlap. Trying to look the same image on an intel graphic card I get the same behaviour.
I think the second one (with the uncommented line) should be preferred as it is similar to the intel card and also looks subjectively better.
I tried the latest patch: bit_depth_ control &= ~AVIVO_ LVTMA_BIT_ DEPTH_CONTROL_ SPATIAL_ DITHER_ EN;
1) with the unmodified patch the banding is fixed, however there are some areas (where there is the colour transition) where the colour is not uniform (like if there were some random noise overlapped);
2) with the uncommented
//lvtma_
the problem is also greatly fixed (I can see very little visible banding looking closer, but I think this is how the image is really) without the noise overlap. Trying to look the same image on an intel graphic card I get the same behaviour.
I think the second one (with the uncommented line) should be preferred as it is similar to the intel card and also looks subjectively better.
Thanks for all your work on fixing this problem.