Inconsistent Playback Artifacting

[Taranli Maren]

I'm trying to play back a clip of a divx5 movie that a friend encoded, an anime. The playback on his machine looks flawless, but on mine, looks like shit. (Compare the examples) It seems to be an issue with motion, when it pans, it leaves almost all of itself behind. Making it often look terribly aliased and streaky. I've reinstalled with every divx5 package, so it I can only assume that it is installed properly. The output looks the same in the playa, wmp, and nandub. I've fiddled with the decoder settings, and uninstalled a variety of my other directshow filters, hoping something would be interfering, but nothing works. I have directx 8.0, win2k and a geforce2 gts (dunno if it could have to do with video drivers)

It was encoded with no qpels, the rest of the settings default.
Bitrate 1680, 2-pass

Bad Frame
http://caeli.cjb.net/~autumnflame/examplebad.jpg

Good Frame
http://caeli.cjb.net/~autumnflame/examplegood.jpg

I have also noticed that it installes *two* Divx Decoder Filters, though both of them play the file the same.

Thanks

[hofmetzger]

i have the same problem ( www.schlachtbank.de/vergleich.jpg ), described it in this thread:

http://forum.doom9.org/showthread.php?s=&threadid=19552&perpage=20&pagenumber=1

but if u say it doesnt depend on qpel, it worries me even more.
my system: amd k6-2 450, win2k sp2, dx8.1, voodoo3

whats your processor?
(dont think someone else with k6-2 here?!)

[Mentar]

Funny. I'm fairly certain that Taranli Maren's computer displaying the very same behaviour is a K6-2 too ...

Still, could be pure coincidence. We need some more voices.

[hofmetzger]

on a friends pc i saw the same terribble artifacts.

amd k6-2 400, win98, tnt1, dx7a

im really getting worried. hope they (divX) fix it

[Mentar]

Well, I can say that I could _partly_ reproduce the problem on a notebook p3-650. It plays back the movie well and smoothly on the playa2.0 (normal and fullscreen) and wmp on normal size, but once I switch to wmp full screen, the same errors surface - playback gets choppy as hell and blocky with fat pixels.

So I believe there must be a misconfiguration somewhere, some silly bug. I hope they'll find it, it's very annoying.

[jace112]

I did notice that the divx 5 playback isn't the best part of the codec. With Qpel, it even crashes my PC and it's really slow...
If I desactivate the Qpel, things become almost fine. The visual quality is rather good (no artifact...), but the speed isn't !!!
Does anyone have the same configuration and good playback with divx 5, or is it very power consuming ? :scared:
My machine:
Duron 750
MSI K7T Turbo
512 Mo
ATI Radeon VE
with Win XP
tested with Fight Club, 1300 Mo, 1180 kbits/s

[Mentar]

No ideas yet? So we have a confirmed error, but no solution for it, right?

[hofmetzger]

i' still testing. i hope that it works without any of the new options...

[Olleman]

I have the same problem as you guys. My video looks fine on my friends computer but terrible on mine :(

P2 450 mhz

,olle

[hofmetzger]

im sure now with not using qpel and gmc you dont have to expect problems.
b-frames are ok.

but i hope someone at divxnetworks finds a solution or makes a fix, cause you could dramatically increase quality if qpel worked correct (as far as i seen on other pcs)

[the oil]

my problem is very similar - the artifacts are not as bad as in most of the samples but still most of the diagonal lines have those artifacts.

my system:
athlon 1.2 GHz (C-stepping)
WinXP
directX 8
geforce 2 MX 400

could it be an AMD/DivX 5 problem ???
anyone having those problems with intel ?

[Mentar]

Do you happen to use Ogg, and in particular their subtitler? If so, I have found a solution which might solve your problems too.

Anyway, a 1.2 gig Athlon is way enough to play back any divx5 content.

[the oil]

what is "Ogg" ?

i'm encoding movies using DVDx 1.8 (it also happened with 1.7) using b-frames, no qpel or gmc (but tried with and without any of these). when watching i tried that with media player and the alpha 2 player from divx.

[Mentar]

This "artifacted" playback happens when during playback the CPU load hits 100%. This can happen especially if you're doing something in the background at the same time, like encoding video or audio or so.

Once DivX5 sees "CPU Load 100%" it panics and goes back to "crap mode" with the mentioned artifacting. Then you have to close the player, end all other applications and start again.

I mentioned ogg because on some systems, because a little problem at fullscreen-playback with the subtitler could force these conditions. Since you don't use it, please nevermind :)

[the oil]

there is usually no other application running when i watch a movie. so the cpu load should never reach 100%. besides, the artifacted playback starts right away when starting the movie.

i will check tonight what my cpu load is when watching a movie.

if there are any other ideas out there...

[the oil]

i checked the processor load yesterday. it's usually around 70% (85% max) but i still see artifacts.

[the oil]

i checked last night again !
when playing movies without qpel the cpu load is around 75%; when playing movies with qpel the cpu load goes up to 100% (almost constantly) !

[Aridyme]

Okay, I've done a bit of research on my computer as I have the same problem.

The artifacting occurs (on my computer) even when the CPU load is not 100%. In fact, it still occurs even when CPU load is less than 50%. Furthermore, I discussed this problem with someone else on a newsgroup. He tested a certain DivX5 encode I was having artifacting problems with: he viewed it on multiple computers, and he said that although the computers were too slow to play the file at full speed, the artifacting did not occur. I don't think CPU load is a factor here.

The problem occurs in VirtualDub/Nandub as well. Going frame by frame, the artifacting appears.

I did some encoding with DivX5, mixing and matching encoding options. The following settings were the only ones that I changed; everything else was at their default:

BFrames, GMC, QPel.

I encoded a 30 second video clip. Video dimensions (both height and width) were divisible by 32. Bitrate was constant for all clips. CPU load on playback of all clips were well under 100%. Here are my results:

BFrames+GMC+QPel: Artifacting.
BFrames+GMC: Artifacting.
GMC+QPel: Artifacting.
GMC: Artifacting.
QPel: Normal.
BFrames: Normal.
BFrames+QPel: Normal.
Nothing: Normal.

As you can see, the problem arises only with GMC encoded videos. Well, for me at least.

I have a P2-350, 32MB Radeon DDR, 384MB RAM running on Win2K SP2 w/ DirectX 8.1.
Nothing is overclocked.

The artifacting still occurs:
...in Win98SE.
...after (multiple) video card driver updates.
...after reinstalling DivX5.
...under both DivX5 lite and DivX5 pro (legitimate, not cracked).
...under DivX 5.01.
...with Sasami2K v757, WMP v6.4, and the bundled DivX player (windowed and fullscreen).
...with *any* postprocessing setting.

Hmm...that's all I have to contribute. Anyone have any ideas?

[Taranli Maren]

I recently upgraded from my k6-2 500 to an amd mp 1900, replacing only the motherboard, processor and ram, reinstalling directx I believe and the artifacting was gone. so I do think the problem is hardware based. It seems to happen with every k6-2 processor its tested with. I did not get a chance to test 5.01 though.

[hofmetzger]

Thx for your work aridyme! so we now for sure that bframes are not dangerous.

qpel seems to be secure too, but:
the question for me is now if qpel is worth it, if the need so much cpu-power... and not to forget: there were other problems with qpel as well...but thats another topic so:

thx again for your work

[the oil]

all my artifacts are gone if i use the divx 5.0.1 pro codec to encode the movie and for play back. :D

when using the divx 5 pro codec it doesn't matter what kind of options i choose (qpel, bframes...) i always see the artifacts.

by the way - are there also certain play back options for the codecs and how can i manipulate those ?