Horrible artifacts when using xvid decoder

[vlix]

When using the decoder included with xvid for decoding, a lot of my xvid files (but not all!) don't play properly. For example, with my Family Guy rips, I get artifacts like these:

http://home.zonnet.nl/fptiele/bscap001.jpg

http://home.zonnet.nl/fptiele/bscap004.jpg

I've tried installing different versions of xvid (including the one released today, and earlier betas and alphas) but that does not make a difference at all.
The only way I can play my xvid files properly is to use the decoder included with Nero 6, which works fine. But I would like to use the 'normal' xvid decoder anyway.
What could be causing this problem? I'm guessing that some codec-pack I may have once installed (don't have any installed now) may have left some shitty file somewhere that is still being used by xvid, or something along those lines, but I have no idea where to start looking, so I could use some help...

Some extra information:
- The artifacts occur with all media players I've tried (WMP6.4, MPC, BSPlayer)
- My system is an Athlon 1600+ with Nvidia Geforce3 Ti200, latest drivers, running WinXP SP1
- I have no idea why some of my xvid files play fine with the xvid decoder, and others don't.

Thanks very much in advance for any help offered!

[atreya2011]

What version of XviD did you use to encode them?

[vlix]

Unfortunately, I don't know... I'm sure you understand...

[crusty]

This looks like the stuff I got last time I used gmc and decodec with DivX by mistake...open the file with drfanalyzer (use the search or google) and see if it says if there are S-frames. (S-frames are frames with GMC).
If the video was encoded with an old aplha build with gmc, it's likely to be b0rked.

Another try:
Uninstall all your codec packs, then install only XviD.
Try #3:
Try another pc.

[vlix]

crusty:

I have tried out drfanalyzer, and it seems you're right about GMC! My xvids with artefacts indeed use S-frames, while my working xvids don't.

So but how do I solve this little problem? I mean, if the Nero decoder (which wasn't made especially for xvid) can play these files, then surely the official xvid decoder must be able to play them as well?

I have already tried another PC, and it has exactly the same problem... but since I had installed pretty much the same stuff on that one (including codec packs), that does not surprise me. In any case, all codec packs are long gone now on both PCs, but who knows what they have left behind...

Anyway thanks for the S-frames tip, at least I know more now than i did this morning :)

[vlix]

Hmmm, I have now found this (http://forum.doom9.org/showthread.php?s=&threadid=70416&highlight=gmc+artifacts) thread, and I guess I have the same problem, since the xvids that I have problems with are all very likely to have come from interlaced sources.

I have also installed a really old Nic build of xvid, and that one does indeed play my xvids flawlessly.

The problem, then, seems to be that the recent xvid betas and RCs cannot properly decode old xvids that were encoded using interlacing combined with GMC.
Does anyone know if this problem will ever be solved?
Thanks very much!

[crusty]

Sincerely doubt it...encoding with both gmc AND interlacing was considered a major no-no and anyone with half a brain should have stayed away from it for anything even remotely resembling non-experimental stuff.

It is a well known rotten combination, and it basically means that most people will have avoided it. That means it's probably a rare issue, and rare issues are not likely to be solved soon, unless a developer stumbles upon a solution by pure accident.

That aside, try using different versions of ffdshow. Maybe one version decodes it properly.
The only way I can play my xvid files properly is to use the decoder included with Nero 6, which works fine. But I would like to use the 'normal' xvid decoder anyway. Well I guess you're out of luck here. But if using the Nero decoder works, why change a winning team?

[vlix]

It is a well known rotten combination, and it basically means that most people will have avoided it. That means it's probably a rare issue, and rare issues are not likely to be solved soon, unless a developer stumbles upon a solution by pure accident.
Yeah, I was afraid you'd say that ;)

Well I guess you're out of luck here. But if using the Nero decoder works, why change a winning team?
Because I got the idea that the Nero decoder can be a bit of a CPU/resource hog, but I never properly tested this, so I didn't mention my suspicions. In any case, I wanted to be able to use the fancy new xvid decoder with post-processing bells and whistles...

That aside, try using different versions of ffdshow. Maybe one version decodes it properly.
Yeah well waddayaknow... I was always under the impression that ffdshow was a long dead project (both the homepage and the sourceforge page haven't been updated for a long long time), so I was surprised to find this (http://forum.doom9.org/showthread.php?s=&threadid=71653) thread, with an all new version. An even bigger surprise was that it plays back my old xvids without a hitch! Hurrah!
Eind goed al goed I guess :sly:
Thanks once again for pointing me in the right direction!

[TorgoGuy]

I don't know if this the same problem as yours--

On one of my low end machines, I would get the same artifacts with XviD decoder. It turned out that it was just when my CPU hit 100% on that slower machine. GMC frames take more CPU to decode (?) so that seems consistent with what you're experiencing.

Maybe Nero is the lesser CPU hog? (I've never used Nero's decoder).

If it is because your CPU is maxing out, disable XviD post processing options or give the latest alpha FFDShow a shot.

[vlix]

The problem definitely did not have anything to do with CPU horsepower: using the xvid decoder with post-processing turned off, the xvids with artefacts never took more than about 25% CPU maximum, which is pretty normal for an Athlon 1600+ I think.
Anyway, as I mentioned in my previous post, the latest verson of FFDshow indeed solves all my problems, so I don't care anymore :D

[crusty]

vlix, can I use these pics in my FAQ as an illustration of the issue?
I'll D/L them and put them on my website then.

[vlix]

crusty, of course you can! I read your FAQ a few days ago, and learned a few new things, so I would be honoured to assist in such a small way in making your FAQ even more useful than it already is :)