Is this interlacing?

[boombass]

I've been reading guides and posts and doing various encodes to try to educate myself. I have been working with the same source throughout, and have managed to get good Xvid encodes using Gordian Knot and now Avisynth and VirtualDub.

But each of my encodes has the same weird effect. I have a ripped a segment from an anime disk (a Cowboy Bebop episode), and when the screen is relatively still (no action) the image seems to bob up and down, like it is slowly vibrating.

I've experimented with every method of deinterlacing used in Gordian Knot, settling on IVTC. It does the best job for this source, but the bobbing still happens. I've even used TMPGEnc to (somewhat) manually deinterlace the clip. (Small question: Is this a good way to do it?)

Is this inherent in the source video? Or is there something else I can do to get rid of it?

Thanks for your help!

[killingspree]

hi,
no i actually think your problem is hardcoded to the source and afaik there's not much you can do about it, sorry ...

anyway, i'm not 100% sure on this...
steVe

[Hiro2k]

Well I actualy know this, it's part of the actual Anime. I also encoded the whole Bebop series and a few episodes did that. It's not your fault, and there isn't anything you can do about it. Sorry for the bad news.


which episode is it?

[Awatef]

This kinda makes no sense.
If you're talking about the R1 DVDs of Cowboy Bebop, the only problem they have is cross coloration (rainbowing around lines).
I think you're doing something wrong while ripping.

1) Don't activate force film in DVD2AVI
2) in your avisynth script, IVTC only, no deinterlacing of any kind!
So your script may look basically like this:

loadplugin("...\mpeg2dec3.dll")
loadplugin("...\decomb.dll")
mpeg2source("bebop.d2v")
Telecide(post=false,guide=1)
Decimate()
crop(8,0,704,480)
BilinearResize(512,384)

[Hiro2k]

I was able to use force film on half of the episodes. And they those looked fine. The ones I couldn't Force Film, I used IVTC 2.2

[boombass]

@Hiro2K:

It's episode 5. I'm using a short segment about 8 minutes in where a couple of kids are stealing magazines from Spike's friend's store. (I can't remember her name!) There is a portion where one kid is running away that is great for testing telecining - lots of motion, with the background moving at a different rate than the kid running in the foreground.

If I can't do anything about it, then that's OK. I just wasn't sure if I was making a dumb mistake!


@Awatef:

I tried your script with a few slight variations: I used different cropping (based on what Gordion Knot's autocrop suggested), and I used Lanczos resize to 640x480. I'm going big on the resize to see if I can get nice encodes with smallish filesizes. I want to try to fit 3 episodes on a CD with two audio tracks (in .ogg) and subtitles, all in an .ogm wrapper.

Anyway, I got the same weird vibrating effect. I'm starting to feel that Hiro2K is right, and the problem is in the disc itself. Looks fine on an interlaced TV, but I guess that's the point.

Any advice on how to fix the cross coloration?


Thanks to you all!

[Hiro2k]

I just looked at the episode your mentioned. And on my rip, the only interlacing artifact I see is at this one at frame 12928.

http://hugogarza.no-ip.com/Pics/episode-5-bebop-interlacing.jpg

[boombass]

@Hiro2K:

Yep, that definitely looks like an interlacing artifact. I checked mine a the exact same frame, and I don't have the same problem. I find that kind of interesting, that two different encodes can have different results (in such a small way).

But it's not the problem I was trying to describe. It's just a slight up and down movement, which is most visible in scenes with little or no movement. I'm pretty sure it's interlacing, and what I'm seeing is the top and bottom fields, although my encode is now progressive.

I'm willing to believe that it is a problem with the source, my R1 DVD. I'll try encoding some other anime DVD's I have, and see if I get the same effect.

I'd like to ask another question, at the risk of getting off topic. I used IVTC to de-interlace the video, and in another experiment I used TMPGEnc. I used the guide on Doom9 for TMPGEnc, and it was quite involved. It was nice to see exactly which frames were being left out. But my question is, are the two methods essentially the same? The results looked very similar. IVTC is easier to set up, so I'd prefer to use it if it is just as good (or better).

Thanks again!

[Hiro2k]

Well as you found out, IVTC in TMPEG is a long process, but it's more exact as your own eyes are the judge. IVTC filters do the exact same thing, but through algorathims that detect interlacing. The parameters you set are basicly the threshold's that will detect the interlacing from one frame to the next. Well at least that's what you use in IVTC 2.2.

ivtc(44,11,95)


I'm not sure what the parameters mean in Decomb. :confused: