Are all encoding programs basically the same

[vorbis]

with the new codecs (xvid, divx 5) does the choice of program have an impact on quality. I know GKnot is useful for getting correct resolution and cropping values. What I mean is will a movie encoded in xmpeg with xvid be the same quality as one done with gknot vdub. Does the codec all the quality options. Thanks

[Hanty]

No, they arenot the same. Only in theory.

[theReal]

You gain or lose a lot of quality and/or compressibility with resizing filters, this is where XMpeg/Flask loses the competition with Avisynth/Virtualdub. If you need to deinterlace or ivtc in addition to resizing, you need good filters even more.
Avisynth filters are just unbeatable, even rather expensive soft like Ulead Video Editor pales in comparison!

[vorbis]

ah nice to know that. I just thought that avx was simply faster

[Hanty]

Avisynth filters are just unbeatable

Not true, there are plenty of vdub filters that have no true competition in avisynth, smoothers for example. There are now avisynth plugins for most of them but they are not more than plugins and still operate in RGB as opposed to native avisynth filters.

[theReal]

I kind of meant VDub as well, mainly because I'm always using VDub together with avisynth. But, we need to mention both, you are right, Hanty. A filter for which I don't know an equivalent in avisynth is VDub's precise bilinear resize. This one is very handy if bicubic resize doesn't produce enough compressibility and it's still way better than any other bilinear resize.