Avisynth: Interlaced sources guide? [See pg2]
 

I find this topic a very confusing one! When it comes to interlaced sources and MA scripts, it just seems like there are too many suggestions floating around. I hope by asking these questions someone could make a "definitive" sticky for dealing with interlaced sources.

- Boulder has a thread MA script for interlaced sources, but for the life of me I just can't get it to work. I guess I am too used to Moviestacker. He mentions stuff like mod4, mod2, and height/2, and despite my best efforts to try that out I can't for the life of me get his script to work.
- Incredible has the thread Interlaced / Progressive ... and what it means: which deals with deinterlacing sources.
- So does Kwag in the stickyConverts 60fps Video into 24fps, but then Incredible makes some suggestions
- and finally, what about Kwag's latest MA optimal script?

My problem with Boulder's MA script for interlaced sources is I simply cannot get it to work as it is. So I combined Incredible's deinterlacing with Kwag's MA script but the encoding right now is sllllloooowwwww.

I'm sorry if I have asked similar questions in the past, but I still feel in the dark on this! I hope someone can shed some light on this issue for me. Thanks

I think the same. And maybe a taslation to spanish language.
:D

I really hope someone can help me. I'm trying to encode a DVD of the movie "Camp". DVD2AVI reports that it is NTSC and interlaced, I do see combing during high action scenes when I preview with DVD2AVI. But I'm so confused by

a) which script should I be using? Kwag's MA optimal?
b) How should I treat this interlaced material? Telicide/Decimate? Bob? Smoothdeinterlace? convert60ito24p? or the multitude of OTHER deinterlacing means?

Despite all the guides out there I still have no way of telling whether my source is "true" interlaced or not, and what the implications of that are. And what about IVTC? Basically if my source isn't Film I am 100% confused about what to do!

Well, if your source is 29.970fps interlaced you have some alternatives:

1- Encode it as Interlaced and keep the 29.970fps. In this case you can use Boulder's script

2- Deinterlace it and keep the 29.970fps. In this case you just use a deinterlacer, like TomsMoComp, FieldDeinterlace, Telecide (without Decimate) and others. You have to choose the one you prefer. After that you can use the MA script.

3- Deinterlace and change to 23.976fps. In this case you can use the convert60ito24p script and than use the MA script.

I have not tested the convert60ito24p script, so I don't know if the results are good. But if they are... I would certainly choose the third alternative.

After a long day of experimenting, here are my results. I tried using convert60ito24p on my film but the results were horrible, with either Bob or SmoothDeinterlace. During camera panning scenes I could definately see where the interlaced fields have been combined (I believe the term is ghosting?). I had the best results using telecide() and decimate(). I'm not certain why you said not to use decimate, but with it my encode was converted to 23.976fps. I then enabled 2:3 pulldown in DVD-lab as I'm making KDVDs. Oh, and I am then using the MA script.

The results so far have been fantastic. I'm encoding with CCE at Q=15, min/max = 64/4500. This compressed a 6 Gb movie down to around 2.5 Gb with really no noticeble difference. In fact the source was rather grainy with noise, and the MA script seemed to do a good job of smoothing the film out.

That's what I feared. :? :(

Because decimating a non telecined movie will lead into a slightly jerk playback. That's a fact.
I've done some movies exact like you describe. Many friends didn't notice the problem at all. But some noticed, and I almost have headaches watching a 2 hours movie like this.

convert60ito24p script must *ONLY* be used on a 100% interlaced source :!:

-kwag

Okay well I think that is where my confusion lies. How does one TELL that? DVD2AVI says it is interlaced but I find this topic so confusing, whether it truly is or not. Ack!

Hmm that's interesting. My encode looks very smooth with decimate, at least a small 2 min clip with camera panning did. I'll check the entire film to see if I notice this. But if I don't, what does that mean about the kind of interlaced film I have?

I just wish there would be a simple and easy way to figure out what to do with Interlaced material. For progressive film material, the criteria are so clear cut. Just check out doom9.org

hard way.....i never understood it completely.....

http://www.doom9.org/ivtc-tut.htm

:?

I asked this elsewhere, but didn't get a clear response.

If I use my DV cam to capture from VHS, will the new "source" be 100% interlaced regardless of the original source?

No. If the source was FILM, it's then telecined to 29.97fps on yor VHS.
You'll get your capture at 29.97fps which you should Inverse Telecine for best quality.
So you have to find out if your capture's original material is FILM or interlaced.

-kwag

I wouldn't do that cause as you already kill the smoothness advantage of 29.97 interlaced as you do deinterlace, then you can also do the next step and apply the 60iTo24p function - as this will result in a much better compresable 23.976 Stream.

So my suggestion is .... if "real" interlaced source is present:
- you can deinterlace but you also then should bring it to 23.976 (60iTo24p function)
- to keep the quality you can encode directly as interlaced but in case of even 29.97 this means a veeeery lot avg bitrate needed ;-)

Ok, you do capture from VHS, but the main question is: What does your VHS material base on??, means: IF you got a hollywoodmovie on your VHS then this has been shot on FILM in its veeery original state before it was brought to VHS. Means they did a telecine on that FILM material (23.976) to bring it to 29.976 VIDEO material (29.97).

HI J-Wo

This is no solution because i am in the same boat as you i have no idea ,i go to doom9 and search the title of the movie and sometimes you can get clues what people did to get it to work.

This version of the MA script should work well with interlaced sources:

i'm in the same boat as you 2, but outside... :oops: (glub)
can a castaway up a board?...thanks.
now we need a navy.... more will come !
:wink:

Hop a board
The more the merrier :D

Jorel your link to http://www.doom9.org/ivtc-tut.htm was extremely helpful! I suggest a sticky should be put up either linking to that article or some bold person do a summerization of it, incorporating changes as needed to suit KVCD/KDVDs.

It did a REALLY good job of explaining whether your source is 100% 29.97 interlaced or 23.976 telecined to 29.97. Turns out my source was the latter, so a simple IVTC (inverse telecine) worked.

That page provides some excellent avs samples to check your source. For example, load your source with and then open that file in Vdub. Advance frame by frame. For my source, I saw a pattern of 2 repeated frames followed by 3 progressive (non-interlaced) frames, meaning I could safely use IVTC. An alternative is to load your source with only MpegSource() with no telecine line. In that instance, you will see 2 interlaced frames followed by 3 progressive frames. If however I saw that almost every frame was interlaced, IVTC would not work and I would have to deinterlace.

I ended up making a script with the following IVTC lines:
and the results were beautiful. The Post=False option turns off the post-processing deinterlacer, which speeds up the encoding process. This is only recommended on very "clean" telecined sources, and it turns out for my sources I still saw a stray interlaced frame every now and then during high action scenes. However the result is hardly noticeable on TV.

Anyway admitadly this topic is much more complicated than I first imagined, but with the help of this forum I'm learning more day by day!

oh yes J-Wo, a long time i posted this :
http://www.kvcd.net/forum/viewtopic.php?t=5664
that have links to that page and some more.
i read it thousands.....
i know that this page is amazing but my poor english don't help me...
Boulder a few months, send me good explanations but it still confuse to me.

in the end of the tutorial is wroten:
"CONCLUSION
The subject is not an easy one if you’re just learning it for the first time.
It will take practice and experimentation to gain a better understanding
of the concepts and methods involved.
But we hope this tutorial will help some of you. "

then i'm out of the "some of you" in the phrase....
i really need a "how to" for stups....like: "do this" if.....and "do that" if don't...
:oops:

Jorel: I think I'll start working on just such a guide! It'll be really simple with straight forward steps, not getting into any complicated scenarios but hopefully will be enough for most users. I'll post a reply to this thread later, let me know what you think!

what i think?
it's very 8) J-Wo !
i'm waiting your guide.

my recomendations:
IF (only if) you have doubts...
ask Boulder, vmesquita, ink, Kwag, muaddib, Phil,
and all the wises to help you too !
send lots of pms if needed!
:lol:

Hi J-Wo

I know I would and alot of other people would appreciate a simple guide :D

NTSC Interlaced Sources
 

NTSC Interlaced Sources - A Simple Guide

The following is a very simple guide on dealing with NTSC Interlaced sources. At this time, I am not covering such topics as PAL sources, NTSC to PAL conversions (or vice versa), or hybrid interlaced sources. My goal is to provide a very basic step-by-step guide on this topic. My apologies if I "plagerize" from other people, but I'll try my best not to!

At this time this guide does not get into any heavy definitions nor does it have any screencaps. There are a number of great sites for those, and frankly the topic gets so complicated that reading too much of it can might just make you more confused! :lol: However I would like to provide two links (previously mentioned in this thread) which have provided me with a lot of insight. If you are at all confused about what I write in this guide, I strongly suggest you check out these links for your further edification:

1) Incredible's post Interlaced / Progressive ... and what it means
2) Doom9's tutorial Force Film, IVTC, and Deinterlacing

So now, onto the guide!

Step 1: Loading your source
This portion assumes your source is DVD. If you are using DV or VHS capture, I believe the steps are the same (but I can't be certain!)

1. Load your source into DVD2AVI and press [F5] to Preview source

2. Take a look at what is displayed in the Information window on the right. If it says NTSC under Video Type and Interlaced under Frame Type, then this is the guide for you! Otherwise you should probably go somewhere else :)

3. Under Video -> Field Operation, make sure Force Film is not selected but instead select None.

4. Press [F4] to save your project as a .d2v file

Step 2: Checking your source
1. Create a simple .avs file loading your .d2v file. The result should look like this:2. Load your .avs file into VirtualDub and move the trackbar at the bottom of the screen to a point in the film where there is movement. Advance frame-by-frame by using the right arrow key on your keyboard. What you are looking for are occurances of "interlaced" frames, which have a characteristic "combing" effect. For more accurate descriptions and pictures, please go to the links provided above! Depending on what you see, you should hopefully fall into one of the following categories:

1) Telecined NTSC FILM material
This type of film source was originally shot at 23.976fps, but has been "telecined" to 29.970fps. In simple terms, that means a certain number of frames have been repeated in order to stretch (or telecine) the material to fill a longer framerate. If you have this type of source, you will notice when advancing frame-by-frame a pattern of 3 progressive frames (non-interlaced) followed by 2 interlaced frames. If this is the case, you will want to reverse the telecine process to restore the original 23.976fps film material by doing what is called an Inverse Telecine, or IVTC.

To do this, we will start off with the following avs file. Please remember to place a copy of decomb.dll in your Avisynth / Plugins subfolder (if you are using Avs 2.5x) or load the decomb_legacy.dll file in your script if you are using Avs 2.0x. Both filters may be downloaded here.
The Post=fale argument turns off post-processing deinterlacer, which will speed up encoding but is only recommended on very "clean" telecined sources. To check this, load your new script into VirtualDub and move to a high action scene, again checking frame-by-frame for any interlaced frames. Here's what you might see:

• If all is good, you will see no more interlaced frames and you are good to go!
• If you see a few stray interlaced frames, then you have two options. First, you can leave things as is since a couple sparse interlaced frames will hardly be noticeable in the final encode. If however you are not satisfied with that, then change the argument to Post=true and you should see no more interlaced frames with the tradeoff of a slightly longer encoding time

2) Pure NTSC VIDEO interlaced material
This type of material is shot at 29.970fps and is 100% interlaced, which means that in our avs script of MpegSource("clip.d2v") we would see in VirtualDub that every single frame is interlaced. One of the best ways to deal with this source is a special form of deinterlacing called convert60ito24p. What this does is it converts the interlaced 29.970fps source to progressive 23.976fps, similar to an inverse telecine. However, note that we are not dealing with a telecined 29.970fps source, so what we are doing is not considered IVTC but is actually a form of deinterlacing.

The following script for convert60ito24p was created by scharfis_brain, whose site is here:
The above script uses the filter Bob which is built into Avisynth. I found it does an excellent and quick job here, but as suggested by Incredible you might want to try SmoothDeinterlace for higher quality. That filter may be downloaded here.

3) Progressive NTSC FILM material
With this type of material, you will notice no interlaced frames when using the simple script MpegSource("clip.d2v"). If this is the case, then you are in luck! What you have is actually a progressive NTSC FILM material shot at 23.976fps, but DVD2AVI has incorrectly recognized it as interlaced. Personally I've never come across this situation but all you have to do is load your VOB back up in DVD2AVI and create a new .d2v project file, but this time enable Force Film. Ta da, this will give you back your original progressive 23.976fps material!

Step 3: Encoding
Before encoding your video, make a final check of either your IVTC or deinterlacing script in Virtualdub and cofirm that your script is free of any avisynth errors and that there are no longer any more interlaced frames. If there are, then either I have made a mistake in this guide, or you have made a mistake in this guide, OR you have a more complicated source that is currently beyond the scope of this guide! :oops:

In any event, once you are ready to encode you are safe to add any resizing or motion adaptive filters you want, as long as they are after the IVTC or deinterlacing lines. I have found Kwag's MA script does an excellent job, but of course there are a multitude of others.

As said in my Guide...

to see if DVD2AVI deals with an interlaced source, you don't need to do a "dummy" avs to see if there's combing. Just use the slider below in DVD2AVI to scroll to a motion scene ..... ;-)

The problem with that is DVD2AVI does not advance frame-by-frame, so it may not be possible to distinguish between a 100% interlaced film or telecined film.

Then load your VOB into Virtualdub ;)

-kwag

Hey I never realized that was possible! However the only problem with that is a) not all versions of Virtualdub can load VOB files. It appears that only the latest versions of VirtualdubMod and VirtualDubMPEG-2 can; and b) it takes a bit for vdub to import the vob file in, whereas with an avs file it's instantaneous.

Besides, since you're likely going to be using an avs file anyway which starts with an Mpeg2Source() line, why not just use that? :)

for a and b :
load the .avs using trim(xxxx,xxxx) and it load faster!

:idea:

J-Wo my son, where are you ?

did i " tilt " the thread?
:?

J-Wo...
we all are waiting for you my friend.
the team don't know that we change some pms
and you're ending details in the guide !
well, ...now they know!
(i posted only to update the thread! )

:wink:

8O i posted 3 times...later i delete some!

This thread has been a really interesting read I also read Inc's Interlaced /Progressive what does it mean (A really interesting read btw :))

Im totally clueless when it comes to Interlaced or Progressive. Seeing as I live in the U.K and we use PAL @25fps for our DVD's I can only assume that most of our DVD's are Interlaced.

I liked your guide J-WO a really interesting read also. :)

Jorel whats your question que queda? :)

I thought everything above also was (maybe in another way explained - but the same content or to do's in the interlaced an what it means sticky).

There won't be an veery fast understanding guide which clearyfies all interlaced questions. :(
What you gonna do if you got a "raped" stream where a pal interlaced 25.000 was just "fieldblended" converted to NTSC 29.97?? ;-) That also would be recognised as a full interlaced 29.97 but a simple deinterlacer would still end up in blendings .. so that would be a case to use rePAL() or better unblendpattern()
.. just an example 8)

So IF theres something not understandable in the Interlacing sticky, let me know! Ill fix/clearify that and If J-Wo got some addings, I will apriciate! to add them to that interlacing sticky (incl. credits for shure :) )

Watch out! IVTC and 60ito24p do got totally diff. approaches! ;-)
When doing an IVTC a frame decimating will be done and a dynamical phase shift will be inversed so the frames will be restored, (the dynamical phase shift on telecined material gives you a smooth movement on TV as the offset of the fields is moved by one field but not static but rather danamically) 60ito24p doesnt perform inverse phase shifts but mixes fields (in mode2, thats why it ends up in a smooth 23.976 movement like motion blur applied).

The advantage of adding a smart bob deinterlacer instead of Bob() is cause bob is stupid and treats EVERY frame as the same in its deinterlacing, even theres no movement. Smart bobbers do got motion detections where only interlaced frames will be treated. That is also done when using fielddeinterlace(full=false) BUT as fielddeinterlace results in a 29.97 NTSC or 25 PAL deinterlaced stream therefore it cant be used to prepare the source for 60ito24p. Thats why we need for 60ito24p a FULL fieldrate deinterlacer where at NTSC 60 and at PAL 50 fps at full size will result which will be treated correctly by the following 60ito24p function .

ok ink!
part of my doubts you posted here too.

you did a great guide for smart guys.
i need that you do an

:arrow: "guide for real stups like jorel"... :!: :cluebat:

i read it all tons but still confused.
Boulder,Kwag,vmesquita, Phil,,GFR,you and more friends always help me
:arrow: but
i need to see pictures like children to do comparisons! :oops:


:imstupid: and ivtc, progressive, ffilm,etc... still :? :? :? for me!

when (and if) i understand it all,
all newbys will learn faster reading this guide !

believe, i don't feel shame to ask for what i don't know!
all that i learn is asking, listening and reading !
don't know a better way and don't have "an ugly proud"!
i'm only an asker ,you and lots friends here are teachers!
for this reason i "bore" you all every day!
... i really don't know it all.
only little parts!

:wink:

I know what you mean Jorel! Incredible, I just read your last post at the last two paragraphs just went waaaaay over my head. I think it's just too technical for me to ever understand. That's why I think we need an easy to follow guide that explains a) what to look for b) determine what type of video you have; and c) what you should do with it. IMHO, all the technical information that explains what video type A is vs. video type B confuses the matter so much more. So does an explanation on how certain filters work! I think many would be happy with a guide which simply shows what things work. Just like the MA script. I don't know what 75% of those filters is doing but because Kwag said it works and there hasn't been much dispute, I use it! Whenever there is discussion and optimization, Kwag updates it. Maybe that's how we should be treating interlaced material. Thoughts?

YEP! :)

We the interlacing Guide should be updated to a more simple understanding one .... I hope I get the time to fix that this week. :wink:

Nice thread...

I'd like to see comments on how you deal with these kind of sources, which I find the most problematic:

1) home videos shoot on a NTSC VHS camcorder.
2) NTSC TV shows or porn tapes/dvds shoot in betacam, super beta or even SVHS.

I always try to keep them interlaced (since may player only accepts mpeg2 anyway), would the 60->24 function work OK for these sources?

All these mentioned sources to me seem to be recorded "fieldbased"! Means Real interlaced where every field (not frame) at half height gots its unique movement.

So you should try the recommendation of
Smoothdeinterlacer(doublerate=true) # or any other full fieldrate deinterlacer, also dgbob(order=x) does that well ... just try spped/quality
convert60ito24p(2,0)

I think if your source comes from a standalone VHS or Camcorder you do digitize that one using for example a HuffYUV or a mjpeg codec. Both do deliver a good quality and they come in YUY2 which got better Chroma subsampling and also there won't be a colorconversation needed BEFORE the function call as convert60ito24p needs YUY2 as input.

:wink:

Even if you choose mpeg2 as encoding format, you can gain MUCH compressibility by converting that one using convert60ito24p. As interlaced encodings do need much more bitrate if the output of quality should be the same as a progressive encoding (according to blocks etc.)

BUT keep in mind .. on the one hand you will get less blocks cause of more compression, but the "smooth" movement of your NTSC VIDEO material will be changed to that typically Film Look playback! And once convert60ito24p is proceeded on the encoding you cant restore it in the future.

ink wrote:
"BUT keep in mind...."

oh, i'm trying my firend ink :screwy:
but my brain now is like "star wars",

the good and the bad are fighting and i only see stars .
:litesbr:

The very big bullshit is that one day the holy lord brought us NTSC 29.97! And thats what does give us all the confusing. :evil:
:wink:

ink, J-Wo, all...
now another reference (too confuse for me):

http://www.hometheaterhifi.com/volum...e-10-2000.html