DVD2AVI, Force Film, IVTC and Deinterlacing

[manono]

Hi-

jggimi, hakko504 and I have written a tutorial on the subjects mentioned in the title. One of the main points is that you can't always trust what DVD2AVI tells you. For most Hollywood type movies, there's no problem deciding how to handle them. But for other kinds, all kinds of screwy things can happen. If you are reasonably new to the wonderful world of GKnot and DVD conversions there might be some useful information in it for you. You can find it Here.

We do request that if you have any questions or comments that you do it in a different thread. Thanks

[maf]

That's very useful, thanks

[techz]

1] We use force film when ...

- The Video Type is FILM 95%+
- What about the frame rate, can it be either 23.976 or 29.97?

2] We use Deinterlace when ...

- The Frame Type says Interlaced
- But do we only set to Deinterlace in the GKNOT settings or
even in the divx codec properties?

3] Is there a difference between FILM and NTSC in the Video type?

4] Also when u preview a vob, the frame rate differs when ff is on and off? Isnt there an unbiased preview mode?

P.S. Us newbies always get told to read the guides before we post anything, so dont worry i've read all i can including your guide

I believe you've written the excellent Auto-GK tutorial, manono. It is very well-written, literate, and, most importantly, not condescending. Thanks.

I do so wish there were a similar tutorial for GK. I had suggested that some time back, and was promptly snubbed that what is, is, and is enough. I do want to learn, for example, more about the many deinterlacing options that GK provides. How to use them, and what the situations are where use of one is better than the others.

And your paper on IVTC, DeInterlacing is superb. Maybe you can add a 2 x 2 table summarizing what stats-combinations DVD2AVI shows on the left column, and what one should do for a given combination on the right ?

Thanks again.

[manono]

Thanks, ukb007, for the kind words about the AutoGK Guide. As I was reading along, I kept waiting for the, "but it's too damn long."

About the DVD2AVI/IVTC tutorial; it was truly a joint effort between the three of us. But it's due for an update, and if I can figure out to make a table, I might just implement your suggestion. It's a good one.

Your request for an explanation of the deinterlacing suggestions in GKnot can also be handled through the tutorial. And that section, especially, needs an update. Some very good deinterlacers have come out since it was written last April.

manono, this is to let you know that I am already eager for the update you mention of your IVTC tutorial. I may be safe in saying that thousands of others will be waiting, like me. You take your time, but hurry up. Regards.

[techz]

As usual i went and read all the newbie guides and got all mixzed up,
The dvd is NTSC and Interlaced, so in DVD2AVI is dont select the Force Film and create the d2v file, then in gordian knot i do all the settings and save the avs using bilinear filtering and FIeld Deinterlace, here is where my question is, should i Deinterlace here, or select IVTC later on? And not to start another thread, are we supposed to do a comp check every time we change the values, becasue

i did a comp check
got 61%
changed the res (w/o doing a comp check)
it showed 66%
did a comp check
now shows 63%, which means to me that everytime i change something i have to do a comp check.

FOR AR (thread is closed) how come even if the dvd's are 2,35:1, 1.85:1, 2.40:1 i a lways get a correct AR only is set to 16:9(1.82:1)

DVD2AVI should tell you in mist cases the aspect ratio that you should use; but I have seen DVD2AVI give erroneous info if the source happens to be erroneously authored (as frequently happens in case of pirated DVDs from some East Asian countries, and these you must assiduously avoid). You apply the AR that DVD2AVI gives you' unless you feel that it's definitely wrong.

A CompCheck result of 61% is acceptable. You can accept values between 60 and 70. And no, you shouldn't need to do CompCheck more than once.

Search and read the article with the same name as this thread in Doom9's guides pages a few times till you feel you get the hang of it. Also read Nicky Pages' article on Interlace. There are many more articles to read. It's not an easy issue to grapple with.

If you consider yourself to be a newbie, then please, at least for the time being, use AutoGordianKnot. One thing about AutoGK is that it truly takes the headache away from the job. It does have some programming breakthroughs not found, as yet, anywhere else. One of them is its handling of this interlace-teleceine issue. You get excellent picture quality, and the interface is truly intuitive. Manono's tutorial is included in the help.

Use Gordian Knot for the sake of learning the works; use AutoGK for immediate finished result. I use XviD, and the quality is unbelievable.

Regards.

[techz]

just mentioning, its an original dvd, i wasnt going against any of the doom9 rules

[Maxim Maximov]

There are some problems if IVTC and Deinterlacing are matched together in GK: the frame rate is still the same (29.970) in the final avi in spite of the IVTC value.

[jggimi]

Our recommendation is to not select both. (I think GK should work properly no matter the combination of settings, and I will try to replicate GK's misbehavior.)

Inverse Telecining -- IVTC -- will reassemble progressive frames, and if using the default DeComb filter set, includes field deinterlacing as necessary for individual frames after reassembly.

In most cases, additional deinterlacing is not required. One can speed up the filter by eliminating the comb test. Merely add "post=false" to the Telecide() filter parameters.

[jggimi]

You can't select both, unless you are manually editing the .avs file. I started with 0.28.7.2 and then upgraded to 0.28.8, and the results are the same.

Only one selection can be made from the "Field Operations" section:

• None
• Kernel Deinterlace
• Field Deinterlace
• Field Deinterlace (no blend)
• Smart Bob
• TomsMoComp
• Inverse Telecine

Can you please read these guides by Mr Nicky Pages ? They are very well written, and are simple, easy to understand.

You can always update the knowledge you acquire from those guides by browsing the excellent doom9 guides. They are frequently updated (excvept the one with the same name as this thread - because programmers are gods and you can see Bruce Almighty to find out how busy God can be). Not that they are always too busy to write tutorials - see the one manono continues to write for AutoGK.

AutoGK has stormed in this cosily maddening atmosphere of Telecine-DeInterlace like a bull in a china shop. There's now a deathly stillness in the battleground - with AutoGK providing an overhead expressway from ripped vobs to finished avi.

Regards.

[techz]

thanks

[TheSeeker]

Techz. A few things i have noticed about GK. I dont know how accurate these things i have noticed are but they always work and i have been using gknot for quite a while. First off i use force film on pretty much everything in dvd2avi. The only exception is anything that was made originally for the tv... the most commonly known example would be Band of Brothers. this was a made for tv special and so then you would not do force film. you would do nothing then save the project file. then in gknot. (not in the codec properties) you would select Field deinterlace only. oh and by the way i would suggest you stay far away from the bilinear resize filter when the source video is very good (like dvd) instead use the neutral bicubic. maybe lanczos sharp. but i suggest the former. so really just remember this: if it was made for the theaters use force film. otherwise use no force film then choose field deinterlace later on in gk. also use neutral bicubic if the source is good and other that i tend like to have a higher resolution than a higher bits/pixel frame or whatever that is. but dont ever go below .22 or so

I dont know how accurate all this is but for me i have always gotten excellant encodes using these general rules.

[jggimi]

When you merely deinterlace telecined content, you "waste" 6 frames every second that could otherwise be removed, making your chosen bitrate less effective.

That stated, TheSeeker, your methodology is one of the workable solutions for hybrid content. I've used it, but never with Telecined-only content.

[Shinigami-Sama]

ok...
I have;nt found many guides onthis and this may help...
I have an anime called "kai doh maru" anf it's ntsc 78% progresive
and I was wondering if I should ivtc or what
this is very confusing...

and this is a farly low motion movie with a few section of high motion about 1min each tops
and ther realy wasn't an anime encoding section so....

[manono]

If you read the guide, then you know how to tell if it's IVTCable. Quite a lot of anime has figures of 60-75% film and can still be IVTC'd. Quite a lot of it has 0% film and can be IVTC'd. However, sometimes you'll find things like interlaced end credits, or 30fps progressive opening songs and other parts. I still IVTC that stuff, since there's so little of it. Anime can be very hard, but have a good close look at it first to help you decide how to treat it. Don't just say it's 78% film, because by itself that doesn't mean a whole lot. Has the whole thing been telecined? That's what you need to know.

[Shinigami-Sama]

ok...
I re-read the guide
so film95%=ntsc5%
ok that makes sense
but I still quite know if I should or not.....
parts of it look interlaced when i ff through section but they only last about 30sec-1.5min
and it says "progresssive" and thats why I'm getting confused about this...

[manono]

Fast forwarding where? In DGIndex? Bad move. Make a .d2v with no Force FILM (since you shouldn't Force FILM it anyway), open it in GKnot, find a passage with movement, and then advance a frame at a time. If you see the telltale 3 progressive frames followed by 2 interlaced frames (which you may not see properly, since there are so many duplicated frames in anime-panning shots may be better to try and find), then you can IVTC it. Repeat that a dozen times throughout the episode, making sure you check the opening song, the end credits, and the preview for the next episode, and if you see that same 3/2 pattern, then IVTC it. However, you may have to tweak the Decomb settings anyway, to get it to IVTC properly. So, if you do use Telecide/Decimate, check the 23.976fps output before encoding, and the finished AVI afterwards and make sure it worked OK. And be sure to read the Decomb manual. It has lots of tips, some of them particular to IVTCing anime.