Decoding bug in Divx 5.1.1!!!!!!

[Fr4nz]

Hello folks! I've encoded the 25th hour, but I've noticed this strange bug in the video:

http://users.libero.it/i3ltt/Cazzate%20varie/Image1.jpg

Another image is this:

http://users.libero.it/i3ltt/Cazzate%20varie/Image1.jpg

EDIT: I've uploaded also a small clip:

http://users.libero.it/i3ltt/Cazzate%20varie/Sample.avi

As you can see there are some macroblocking on vertical lines (these strange effect occurs only sometimes and generally when these vertical lines are bright, dunno why).

When you see the film in motion, you can clearly observe that these squares goes up and down the vertical lines, and this is very annoying.

The overall quality of the film is excellent if we don't consider this strange effect.


The options I've used are: 2-passes, bitrate 1330kbps, bitrate modulation 0.02, update log file, profiles disabled, b-frames, max keyframe interval 300 (maybe I have to change this to 250 because the film is PAL??).

I used XMPEG 5 final version.

Thanks for any help!

EDIT: Dimzon told me that this is a decoder 5.1.1 bug and so he's suggested me to try playing the film with FFDShow. I've tried to play the movie on my Kiss-450 and in fact there's not this macroblocking bug. So it's a decoder bug.

Thanks for any reply Gej!

[Tuning]

Hi Fr4nz,

This is definitely a decoder bug (or artifacts). I checked your uploaded clip with FFDShow and could not reproduce it. This has been happening since the final DivX 5.1.1 decoder. The first beta decoder hasn't this kind of artifacts. I bet you could not see this if you'r using beta decoder or FFDShow. The same thing happens when decoding XviD content. Beta was fine.

To DivX developers :
These are threads related to same problem( DivX and XviD ), please look:
MPEG4 artefacts (http://forum.doom9.org/showthread.php?s=&threadid=65833)

DivX5.1.1b decoder and its advantage over XviD files! (http://forum.doom9.org/showthread.php?s=&threadid=64075)

[Fr4nz]

You're right, it's a decoder bug. let's hope divx team fix this bug soon.

fr4nz

[DigitAl56K]

Hi guys,
We've known about this issue for quite some time, its caused by the de-blocking where there are high contrast vertical edges in a block (e.g. along the edges of anime characters etc.). Turning of de-blocking (or partial PP) will prevent it until the decoder is officially updated.

[Fr4nz]

Do you know if there are other issues with the decoder?

I suggest to put this thread as "sticky", so the people stop asking other questions regarding this bug ;)

[jggimi]

Stuck.

[Josip Tosic]

Originally posted by DigitAl56K
Hi guys,
We've known about this issue for quite some time, its caused by the de-blocking where there are high contrast vertical edges in a block (e.g. along the edges of anime characters etc.). Turning of de-blocking (or partial PP) will prevent it until the decoder is officially updated.
I thought it was the decoder as well but then I noticed the same artefacts in VirtualDubMod's preview. And VirtualDubMod doesn't use DirectShow decoding filter - "DIVX.DLL" doesn't have deblocking, right?

[DigitAl56K]

Yes, DivX.dll (the VFW decoder) will do some deblocking also. If thats a problem for you then its possible to disable it by changing the post-processing value in the registry. I think you just set it to 0 but I'd need to check with Gej to confirm that (you can always test this yourself).

[Fr4nz]

Digital do you think we'll have a new de-bugged version of divx decoder soon?

[ChAoS Overlord]

Originally posted by Fr4nz
max keyframe interval 300 (maybe I have to change this to 250 because the film is PAL??).

Kinda off topic, but I've been wondering about the same thing. Should it be 300 or 250 for PAL?

[DigitAl56K]

The recommended value is around 10 seconds, so probably 250 frames - however its fairly unlikely for most content that the encoder will run this long without a keyframe anyway.

I certainly haven't had any problems using a 300 frame interval and all my videos are PAL.

[Fr4nz]

2 months are passed since the "discover" of macroblocks on vertical lines produced by the DivX 5.1.1 decoder...when will be corrected this bug?

[jggimi]

@ Fr4nz: I've merged your complaint thread into the original bug discussion, for clarity.

[Gej]

Hi,

We release a new installer bundle that contains a new player build and a fix for the deblocking bug.

http://www.divx.com/divx/

What's new in DivX 5.1.1 - Build 1031-NipTuck
------------------------

No changes in the Encoder

Decoder fixes:
- Resolved a annoying deblocking bug


We are currently working hard on the next version that'll have substantial encoder improvements...

[Fr4nz]

Great Gej! Thanks for the bugfix! DivX team is great! :D

[bond]

Originally posted by Gej
We are currently working hard on the next version that'll have substantial encoder improvements...great!
now someone again should say open standards (aka strong competition) dont influence quality improvements

btw would be great if we could have .mp4 output support back :)

[SeeMoreDigital]

Blimey,

Your new DivX5.1.1 and DrDivX1.0.4 installers are considerably smaller than the previous versions.

I also echo bonds comment about MP4 container support. Also, anamorphic signalling in the Mpeg4 stream would be nice too, especially if your player could handle such encodes 'automatically'.

Cheers

[DigitAl56K]

Hi guys, we have a fix for this issue, please see:
http://forum.doom9.org/showthread.php?s=&postid=450955#post450955