To defeat pixels artifacts

[Calabuig]

Hi, I'd like to reduce the pixel artifacts that you can see in the attached photo. I use CCE to encode my SVCD. I think that I should use a filter like "Temporal Cleaner" or "Smoother". Is it right?
And the best settings?
Can you help me?
Thanks in advance!

[Kedirekin]

Actually, Temporal Smoother probably won't help much here. This is a fairly common problem with large, flat, almost-monochrome areas.

You said you're using CCE. The first thing I'd try is increasing the image quality priority. If you're using 17, try bumping it to 25. Beware though - while increasing the image quality priority should reduce this posterization effect, it also increases mosquito noise.