Welcome to Doom9's Forum, THE in-place to be for everyone interested in DVD conversion.

Before you start posting please read the forum rules. By posting to this forum you agree to abide by the rules.

 

Go Back   Doom9's Forum > General > Newbies

Reply
 
Thread Tools Search this Thread Display Modes
Old 26th May 2018, 05:57   #1  |  Link
Logan9778
Registered User
 
Join Date: Mar 2017
Posts: 112
Any way to remove this dot crawl?

Hi guys.

Got some help from some people with the Batman TAS ghosting problem, and it turned out that it was a blended chroma. So with their help, I got some code that de-telcined the luma and unblended the chroma, then put it all back together again.

Now I'm left with a dot crawl? problem. Pretty sure it's dot crawl. Rainbow looking bleed on the black lines making up the figure of the character, etc.



Any suggestions?

I've tried a couple, including tcomb(), but nothing seems to touch it. Probably because of the blended chroma.

Last edited by Logan9778; 26th May 2018 at 06:05.
Logan9778 is offline   Reply With Quote
Old 26th May 2018, 07:29   #2  |  Link
Sharc
Registered User
 
Join Date: May 2006
Posts: 3,591
If your source is NTSC mpeg2 720x480 try
http://home.earthlink.net/~tacosalad.../dotcrawl.html
It proved to be effective for some cases here. See also the Usage Notes.

It's a Vdub plugin but you can import it in avisynth.

Last edited by Sharc; 26th May 2018 at 07:34.
Sharc is offline   Reply With Quote
Old 26th May 2018, 07:36   #3  |  Link
foxyshadis
ангел смерти
 
foxyshadis's Avatar
 
Join Date: Nov 2004
Location: Lost
Posts: 9,462
Stubborn rainbowing that doesn't respond to the normal restricted tests of dedicated filters are best smacked with fft3dfilter.

Code:
fft3dfilter(sigma=2,bt=3,plane=1)
fft3dfilter(sigma=2,bt=3,plane=2)
Play with sigma, sigma2, sigma3, and sigma4 as necessary. As a side effect, flat areas will get flatter; good for anime, bad for live-action.

BTW, Dot Crawl is the mirror image of Rainbowing; it's a checkerboard pattern in the luma arising from the same crosstalk that causes rainbowing in analog transmission. (Your capture looks more like digital-induced rainbowing, which is probably why it doesn't respond to rainbow-specific plugins.)

__________________
There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order.
foxyshadis is offline   Reply With Quote
Old 26th May 2018, 20:52   #4  |  Link
Logan9778
Registered User
 
Join Date: Mar 2017
Posts: 112
Thanks guys!

The fft3dfilter helps a little when I up the sigma to 10, but I'm still getting some minor rainbowing on the pic of the security guard and some other scenes. One fat black line on a blimp was also REALLY rainbowing, but sigma=10 tones it down a lot. sigma=2 has little effect.

Here's the code I'm using so far

Code:
LoadPlugin("C:\DGDecNV2053\DGDecodeNV.dll")
loadplugin("c:\program files (x86)\avisynth\plugins\fft3dfilter.dll")
SetWorkingDir("C:\Program Files (x86)\AviSynth\plugins")
SetMTMode(5,6)
DGSource("F:\Test Space\batman\title01.dgi") #source
SetMTMode(2)
y=tfm(mchroma=false).tdecimate(cycle=5) #ivtc and decimate original luma
blank=utoy().spline36resize(720,480) #fake luma (overwrite the y with u) So, uuv, u is now luma.  v is untouched.  No weight option.
mergeluma(last,blank) #fake blended yuv (last is the original clip) default weight is 1 (100% lumu from clip2, i.e. blank) now we have blank's luma, and source chroma.  So luma is still just u. v is untouched.
srestore(omode="pp3").tdecimate(cycle=5) #fix chroma blend and decimate
mergeluma(last,y) #merge back original luma
fft3dfilter(sigma=10, bt=3,plane=1)
fft3dfilter(sigma=10, bt=3,plane=2)
Some guy told me all the shows like this were mastered in S. Korea back in the 80's and 90's on really crummy equipment, so that's probably the bulk of the problems. Looks like they had crazy ideas on how to do things as well.

Here's a clip of the security guard .m2v if anyone wants to look at it.

https://mega.nz/#!SfpxxC5A!QrPZufKo7...DjwCoC5gyxRudY

So, I've seen a definition of dot crawl, but can't find one for rainbowing. Is it the chroma leaking into the luma channel (not that I understand how that works)

Last edited by Logan9778; 27th May 2018 at 04:10.
Logan9778 is offline   Reply With Quote
Old 29th May 2018, 06:09   #5  |  Link
foxyshadis
ангел смерти
 
foxyshadis's Avatar
 
Join Date: Nov 2004
Location: Lost
Posts: 9,462
I guess I shouldn't make that much of a distinction; if you UToY or VToY a rainbowed'd clip it would look just like dot crawl. The main difference is that you can use much harsher blurring to make it look good than for dot crawl, since a little chroma bleed is more tolerable than edges disappearing.

The whole problem comes from luma and chroma being mixed together in composite video and then unmixed. Not only is the process lossy at certain high frequencies, there's an enormous amount of RF interference that tends to get picked up by the unshielded cables that act as an antenna; channel 3 or 4 is normally used, but usually someone is transmitting on them in the vicinity, making noise even worse.
__________________
There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order.
foxyshadis is offline   Reply With Quote
Old 3rd June 2018, 04:48   #6  |  Link
Logan9778
Registered User
 
Join Date: Mar 2017
Posts: 112
Thanks. Sorry for the late reply. My computer finally crashed on me.

I'll try and mull all this over.

Last edited by Logan9778; 3rd June 2018 at 08:00.
Logan9778 is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 00:03.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.