Anime IVTC Trouble

[Taranli Maren]

I'm having trouble with the ivtc for GTO. I've tried just about everything I can think of, including several different ivtc dlls, of course including decomb. Also, I ran through just about all the decomb settings that I thought would make a difference (guidance, thresholds, field order), nothing seems to help. I get major ghosting, or heavy interlacing artifacts if post-processing is turned off. I was hoping that someone might have time to look at a source clip I made (vob) and see if they could help. Its 100% interlaced.

Since my bw is not endless, I'll give the url to anyone who has the time and will to check it out.

[neuron2]

Did you make any attempt *at all* to figure out why it is happening? For example, have you considered the scenarios described in the Decomb help file in the section called "Notes on field matching"?

I'll help you if you have ruled out blended fields and hybrid material. Otherwise, everything I have to say is in the help file, and has been described in this forum many times, and I'm getting a little tired of repeating it all the time.

And why the heck are you doing IVTC if you believe it is "100% interlaced"?

[Taranli Maren]

when I say 100% interlaced, I mean 100% ntsc (read from dvd2avi). I'm sorry if interlaced is not the right term. This is not to say that every frame is interlaced. Is it not recoverable if thats true? I'm sorry if my knowledge is not as complete as it should be. :(

And yes, I've read through the help, and have tried everything I can think of, but it always outputs combed frames (or ghosted).

[neuron2]

I'll be more direct this time. :)

Did you rule out blended fields? Yes or no?

Did you rule out hybrid material? Yes or no?

If my help file is unclear, please tell me so I can fix it. Thank you.

[Taranli Maren]

Uhm, I'm sorry. I may have wasted your time. it looks like it might be blended fields. That is, there is ghosting when I use SeperateFields. There is nothing that can be done to correct this?

Your help file is not unclear, there is just so much there that its hard to absorb and understand everything.

[neuron2]

Yes, Taranli, I confirm from your VOB that your analysis is correct and that it contains blended fields. My only addition to what the help file says (and which I will now add) is this:

Only in very rare cases is it possible to recover progressive frames for all the frames of such material. The user needs to keep things in perspective and not agonize over the fact that when single stepping, some ghosting is seen. After all, even the original material, when viewed as fields on a TV, has blends! You don't notice them. Similarly, when the clip is processed with Telecide and blend postprocessing and played at normal speed, the blends are not objectionable and unprepared viewers notice nothing wrong.

As far as wasting my time is concerned, it was not, because you have diagnosed the problem yourself and are now an expert on blended fields. You'll be able to help the next fellow that posts with this problem. :)

Best of luck for all your encodes!

[Taranli Maren]

Damn. Well, thank you so much for coming to my help :)

I guess I'll just bite the bullet and deinterlace.

[neuron2]

I hope you mean do postprocessing with Telecide! You do want Telecide because it will give the best match of the bad ones available, and thereby minimize the area of combing.

Also, I'm still undecided whether that GTO material should be decimated. What do you think?

Looks like Decimate(mode=2,threshold=1.0) might be good.

[Taranli Maren]

Yes, FieldDeinterlace(full=true)

It actually doesn't look like there are many frames close to duplicates, so I should probably leave it 30 fps. But I might try it with decimate to see how choppy it plays.

[neuron2]

You say yes and then contradict what I said!

Sometimes I wonder whether I don't speak English right. :)

You want Telecide because there *are* some progressive frames in there and even the blended fields will be given the best possible matches, even though they are not perfect. That will reduce the extent of combing. I used this:

avisource("gto.avi")
Telecide()
Decimate(mode=2,threshold=1.0)

[Taranli Maren]

What? I thought FieldDeinterlace is the same as Telecide's post-processing, and that they were both deinterlacing. The doc mentions that for sources with blended fields almost every frame, the best might be FieldDeinterlace(full=true). I think I understand now.

[neuron2]

Yup, that's it. I can't speak English. :)

[Taranli Maren]

No, its my fault. I didn't read it right.

Thanks again for the help :)

[neuron2]

I suppose there is room for reasonable doubt about it. Sorry. :)

Although surely nowhere near all the fields have blends, all the fields with motion seem to! But there are lots of duplicate clean frames with no motion because it is animated like that -- low temporal resolution. And by the way, this is a really crappy mastering, isn't it? Jumping frames, noisy as heck, stupid noisy white bars across the frame. It's just horrid. And those dumb artists don't know how to draw a nose. Still, it's a fun series to watch; I enjoyed it.

But as they say, garbage in -- garbage out, as far as the encoding is concerned.

[Taranli Maren]

lol. Thats so true, you'd think that most new releases would be mastered much better. At least, that seems to be the trend. But damn, talk about a big step backwords. If you can get past the constant panty shots, it is pretty interesting though.

[SansGrip]

neuron2: Yup, that's it. I can't speak English. :)

lol. This is the funniest exchange I've read in ages ;)

[neuron2]

@Taranli

Who wants to get past them? :)

@SansGrip

We aim to please.