What kind of noise is this?

[Raere]

I'm trying to encode End of Evangelion, and I'm getting this annoying sort of noise that keeps popping up randomly. I've never encountered it before, so I don't know what would get rid of it.

Here's one sample:

http://i3.photobucket.com/albums/y98/Raere/evagrab1.jpg

http://i3.photobucket.com/albums/y98/Raere/evagrab2.jpg

And my script:



DGDecode_mpeg2source("D:\End of Eva\movie.d2v", idct=5, info=3, cpu=6)

ColorMatrix(hints=true)

Telecide(guide=1).Decimate(mode=3,threshold=2.0)

Bifrost(interlaced=false, conservativemask=true, variation=6)

crop( 20, 70, -24, -68)

Spline36Resize(720,400)

toon(strength=0.3)

tweak(sat=1.2)

msharpen(threshold=10,strength=30,mask=false,highq=true)

deen("a3d",4,11,13)


Thanks!

[Terranigma]

fft3d, sigma2 should be able to get rid of it. :P
give it a try.

[MadRat]

I'm afraid Raere that you've encountered the dreaded "dot crawl". :scared: Dot crawl is caused by cross-chrominance noise, usually by a weak video signal, around areas that are digital (like subtitles or graphics on the local even news, digital broadcasts, etc.) Like a lot of people I've tried just about everything to get rid of dot crawl and I'm afraid you'll never be able to get rid of it completely. What works the best is tritical's tcomb (http://web.missouri.edu/~kes25c/) but before you get too excited there are some restrictions.

It will ONLY work with NTSC material, and WILL NOT work with telecined material where the rainbowing/dotcrawl was introduced prior to the telecine process! It must be used before ivtc or deinterlace in order to work.
...
TComb currently supports YV12 and YUY2 colorspaces.

I could be wrong about all of that, maybe things have changed since I last tried to remove dot crawl or maybe my facts are off and someone is going to scold me for it. But at least the documentation for tcomb is pretty good. You'll have to tweak two of the settings but the documentation gives you a simple explanation.

This article is outdated but will give you some dot crawl information.
http://www.doom9.org/index.html?/capture/chroma_artefacts.html

[Terranigma]

No, you're correct. I know that sigma2's able to remove it too at the expense of detail. It's been so long though since i've came acrosss it, that I forgot what it was called.
This's what I used to use to remove dotcrawl:
tcomb(mode=0,fthreshL=3,othreshL=4)

filters the artifact successfully without too much damage to detail.

[Raere]

Thanks to you both! TComb reduced the most of the noise with the parameters you gave me, Terranigma.

[Adub]

You can probably reduce all of it with just a little tweaking of those parameters. Read the filter's readme for a description on how to do this.