@ Q-W-Y: Mpeg isn't obsolete, it simply is sharper than H.263. It preserves more detail. Since noise usually comes in the form of fine but unwanted detail, Mpeg QM will retain more of it than H.263 and the resulting file will be bigger. If you just want to remove the noise and don't necessarily want to retain the detail, stick to H.263 and use an avisynth filter like Unfilter() to soften the picture. That's bound to take care of the noise. If you want to do it more intelligently there are many avisynth filters that filter noise out.