What's with XviD and the vertical banding?

[suspiciousBob]

In all XviD encode that I have done or seen, there is always present many fine (but visible) vertical bands. They're not so obvious on my 17" crappy monitor, but on the 21" trinitron they're very blatant.

I've tried encoding using different settings, and using different playback filters to no avail.

Example:
http://www.rubadub37.freeserve.co.uk/EminemXviD.jpg
This image is from an 8-Mile XviD encode. It's been enlarged x3 to show the lines off more obviously.

Is there any reason why they're present (and yet DivX doesn't have such obvious lines) and what can be done to remove them (either at encode time or at playback time)

I would have assumed that if no horizontal banding occurs, then it would also be possible to get rid of this vertical banding.

Any words appreciated.

[Calculon]

I have noticed this with the 7-16 build by Nic. I just change the fourCC of my avis(before i mux them into Matroska) so the DivX decoder will take over and the problem goes away. Your problem is probably the decoder as well. You could change the fourCC(to "DIVX" or "DX50") or just use ffdshow to decode xvid. It works for me, but results may vary. ;)

[suspiciousBob]

Thnx for the suggestion. I have done that, but now the XviD's play back jerkily (may be an audio muxing problem, i'll have a look) but with the May 23 2003 ffdshow DS filter, the lines do indeed go away, but the picture quality doesn't look as sharp; this may just be an illusion or something tho, with the vertical bands splitting up 'smearing' in low bitrate scenes.

BTW i forgot to mention, I didn't do that 8-Mile encode, but when I do my own XviD encodes using Nic's 16/07/03 build I still get this vertical band problem on playback.

[chilledinsanity]

I've just started getting this problem too, your post saved me some time, since your picture illustrates exactly what I've been seeing. It's definitely related to the decoder since I encoded my movies with Koepi's build and they look fine in Virtualdub, but I get this crappy vertical banding when I play it back using Nic's decoder. This is weird because his was working really well for me earlier. You can try using somebody else's (Koepi's, UManiac's, ffdshow) and that should take care of the banding, but the picture doesn't look quite as good to me (compared to Nic's before this banding started).

Let me know if you find out anything else.

Oh, if you didn't know, the decoder file is located in \WINDOWS\SYSTEM32\xvid.ax

[chilledinsanity]

I just did a system restore and that solved the vertical banding problem, so that now Nic's filter looks the best (to me) like it used to. Unfortunately I've made a ton of changes (including an installation of SP1) between my last restore checkpoint, so it's going to be a pain to get back to where I was. I'll post here if I find out what caused this.

[PowerMacG4]

Different IDCTs? Walken vs Simple?

[Koepi]

PowerMacG$:

most likely that's an issue here.

Chilled:

Unfortunately you did that system restore - you could've tried to set the IDCT in ffdshow so that we can check if it were realted to that - then the solution would've been simple, too.

@all:
if someone still has that problem please try different IDCTs in ffdshow (after that configuration completely close the player and restart it "from scratch" to make the changes takes effect) and report back that would be nice.

Regards
Koepi

[chilledinsanity]

I actually tested it with multiple decoders including ffdshow. It was not present in ffdshow, Umaniac's, nor your decoder. I simply prefer the way Nic's looks to those, especially to ffdshow, since it will cause bleeding (even with error corrections enabled and multiple IDTC's tested) occasionally with some clips. Actually I think I'll make a seperate post on this issue. Thanks for the interest, suspiciousbob, you have any luck yet?

[jrhan1]

I seem to also have the same problem...only worse. I downloaded the XxiD codec and all. Installed it. Restarted my computer. Did everything imaginable and I'm still not able to watch any of my XviD movies on Windows Media Player. I tried another program called "Vidomi". That program played the XviD files, but it would suddenly close itself at around 5-7 minutes into the movie. I've tried BS Player also, but that gave me the same results as Windows Media Player. Now I have no idea what else to do to solve this problem! :confused: :confused: :confused:

[sysKin]

Originally posted by jrhan1
Now I have no idea what else to do to solve this problem! :confused: :confused: :confused: Hi, welcome to the forum jrhan1.
If you don't know how to solve a problem, I suggest to read and search. Ffdshow was mentioned several times in this thread alone....

I'll just give you a straight answer this time: you DO NOT NEED xvid codec to play xvid movies. There are several decoders available, and ffdshow might be the best of them. If you don't like it, check 3vix. If you're trying your luck, check divx5.1. There is more. Unfortunately, xvid's internal decoder is pretty bad (but some people like it, mainly due to Nic's great work with dshow filter).

Radek

[Joe Fenton]

ffdshow is possibly best on fast systems. ffdshow is arguably the slowest decoder out; on slow systems, even turning off the post-processing doesn't help play videos through ffdshow without serious skipping. All other decoders are much faster with the DivX decoder leading the pack for speed on slow systems. It's one reason most encodes on the net have the fourcc set to DX50.

My experience on a 350 MHz PII is fastest to slowest: DivX, 3ivX, XviD, ffdshow. On a hi-quality encode of Cowboy Bebop, DivX was easily three times the speed of ffdshow (both set to no post-processing).

Fortunately, very few people use systems this slow anymore. :D

[PowerMacG4]

After a bunch of testing (I found the same problem in Signs), I realized the problem is probably with mpeg2dec3.