Has anyone else used GMC with quarter size encodes?

[TrinitroToluene]

Hi, long time reader, first time poster.

With my Divx5 tests (2 pass) I've found that GMC causes blockiness and artifacts when encoding at quarter resolution, while QPel does help (as the guide suggests). I just want to confirm what I'm seeing with others that are having problems with GMC or encoding at quarter size.

[Acaila]

Yeah I've read quite a few posts where people describe problems with either setting. It seems B-frames is the only safe one to use atm...

[gregor7777]

I've used GMC and Bi-directional in all the movies I've encoded with D5 and they've come out looking great, a notch above my D4 movies actually.

But, I've heard a lot of conflicting stories. I just got a chance to read that article over at THG where they say it's a good idea to use quarter-pixel if you'll be outputing to a TV. If I remember correctly, doom's guide says that feature is pretty much broken ATM.

Anyone have some more info on this subject? I've yet to try quarter pixel myself, so I can't say I have anything useful here.