small white blocks flash briefly

[Striker55]

Hi there,

I've been using Gordian Knot for quite some time now and have always managed to rectify problems by searching these forums. However this one really has me stumped. Perhaps due to the fact this particular problem is so hard to define.

I've recently bought a new computer and once I had encoded my first xvid on said computer, I noticed these tiny white squares (usually interspersed with tiny black lines or dots) flash across for about half a second. They're diverse in size and appear all over the screen. After encoding several different dvd's ranging from episodes to long or short films at varying settings I realized this might not be going away on it's own. The vobs dvddecrypter produces seem to be 'white annoying box'-free.

I'm using GKnot version 0.35.0 and have tried both Koepi's latest stable as well as the latest beta of xvid. I use ffdshow to decode these files (and it does not show any of these little white squares of insanity on any other xvid file).

I've enclosed a jpg of a picture I MADE in a paint program. I wasn't able to take an actual shot of the culprit as they seem to appear between keyframes.

I'd really appreciate any help that can be given on this issue.

Thanks,
David

My current computer configuration:
Windows XP
AMD Athlon 3000+, 64bit, Socket 939
about a gig of RAM
Nvidia 6600GT

PS: To any of the guys who work on these amazing projects for FREE. You guys ROCK! I really can reiterate enough how incredibly cool these programs are!

[jggimi]

Hello, and welcome to Doom9's forum.

...I've recently bought a new computer ... I wasn't able to take an actual shot of the culprit...

It's just a guess, of course, but based on those words, I believe the problem might be your video driver.

You can check to see if this problem occurs in the .avi, or only on playback, by opening the .avi file in VdubMod (packaged with GK). Using the slider and arrow keys, step through the scene in question.

If you see the phenomena in the encoding, let us know, and we'll move this thread to the XviD forum.

If not, it is likely one of these three: your video driver your decoder if using an MPEG-4 decoder other than XviD -- such as ffdshow your .avi player.

[Striker55]

First of all thanks for the prompt reply,


check to see if this problem occurs in the .avi

I have and indeed it seems to be in the avi. I wasn't able to take a snapshot before as I was using Media Player Classic which goes to the nearest keyframe (of course!)...

I've used VDub now to take a snapshot...
so here's an actual snapshot of the problem.

So my next step would be to notify the xvid board?


Thanks again,
David

[jggimi]

I've moved the thread to the XviD forum for you.

[Koepi]

The first step would be to make the problem reproducable.

Do you have a sample which always shows this behaviour while encoding?
Is your system overclocked?

This might be bad memory as well as it just happens with your new system - and I haven't heard any other report like this for many months...

Then we might be able to find out what's happening.

Cheers
Koepi

[Striker55]

No, the system is not overclocked. I'll have to get back to you on the memory until after I've run memtest86 a couple of times (I'm using the computer quite intensively at the moment, so I haven't had the time yet).

It seems to occure pretty sporadically in every avi I create. But I think it's more prudent I get back to you after I've done the memtest.

Thanks,
David

[unskinnyboy]

Best way to ensure that XviD is not the culprit here is to burn the .avi onto a CD/DVD and playing in another PC (your friend's PC?) -or- cut an avi sample and upload to http://uploadhut.com/ and link us.

This is interesting.:)

[drcl]

I saw this kind of thing before when I used a custom quantizer matrix on an mpeg 2 file i made with mplayer/mencoder.

sorry I cant remember the matrix, it was some time ago. I noticed it while playing it back on my dvd player.

I know nothing about quantizers though so all I can say is try using a different matrix.

[Striker55]

This might be bad memory

I've let memtest run for a few passes: 0 errors.


Best way to ensure that XviD is not the culprit here is to burn the .avi onto a CD/DVD and playing in another PC (your friend's PC?)

I can use my brothers computer, however he's in there with his girlfriend at the moment so I won't be barging in there just yet :).


when I used a custom quantizer matrix

In the meanwhile I'm going to try the default settings button. I don't know why I haven't tried it before, probably because I haven't changed the setting at all and it's a relatively new installation.


Oh well,
fingers crossed

[Striker55]

I've just encoded it with 'load defaults' and setting it to "Profile @ level: AS @ L5", but to no avail... those little white boxes are still flashing... ominously.


And I've tried the produced avi at my brothers and it managed to duplicate exactly the same problem. It seems he uses the divx decoder so we can pretty conclusively write off any wrong doing attributed to the decoder.


So what exactly would be the next step?

[Striker55]

I've uploaded an extract to uploadhut.com.

See what you make of it...

http://uploadhut.com/view.php/71300.avi


Any help would really be appreciated.


-edit-
direct link: http://uploadhut.com/view.php/71300.avi

[communist]

Yep I see these blocks (white / black / color) too in the sample. Decoding with MPC / ffdshow 20052202. Did you check if these arent already in your source (avs/vob)?

[Striker55]

Did you check if these arent already in your source (avs/vob)?

Yes I did. No menacing blocks in the vobs.

[Koepi]

Bitstream version 39 means you use a recent build to encode.

I don't have the necessary tools to further investigate here at work, but since noone else is reporting this issue I _fear_ it's something with your system.

Can you take the source snippet (without the blocks) to your brother's computer, encode it there and see if this issue still is occuring?

Thanks
Cheers
Koepi