why won't the sky smooth out properly?

[Amateur]

http://i55.tinypic.com/11jowbc.png

when viewing the source, the sky (above homers head in this shot) looks fine but when i open it up in both MeGUI or AVSPMod it starts to look goofy and it doesn't smooth completely out with such smoothers as removegrain(mode=1)+edeen+dfttest. i even tried gradfun2dbmod or whatever it is but that didn't seem to do anything

this is from the blu-ray source so i am unsure how to provide a sample for others to test out. my usual method of DGIndex and getting a 15 second sample doesn't seem to work.

[CWR03]

You'll never get it to "smooth out" completely using DivX, Xvid or x264. It has nothing to do with filters - it's simply an effect introduced by the way these codecs compress.

[Blue_MiSfit]

Try turning on the "deband" filter in ffdshow during playback. This will apply some simple dithering which helps hide this kind of problem without adding too much visible noise to the picture.

Derek

[Amateur]

wow really? this is a common issue even with blu-ray? what causes it?

[CWR03]

It has nothing to do with the source, and I already explained what causes it. Part of the compression is to reduce the number of colors, so instead of a smooth gradient you get bands of color where it fades. You can make it less noticeable but you can't get rid of it.