How do I deinterlace PAL extras the best way?

[dogleg]

Hi!

In almost every PAL dvd the main movie is progressive and the extras are interlaced. I assume they come from a ntsc videocamera. How do I deinterlace PAL extras the best way for my dvd-backup?

I've usually just add decomb.dll's Telecide() but I get frames with ghosteffects and the motion gets jerky. Fielddeinterlace gives me worse results.

Any ideas anyone?

[scharfis_brain]

hm.. could you make a sample with high motion available? (panning cammera)

[dogleg]

do I make an avi of the the mpeg2 stream? I don't know how to cut in a m2v file

[scharfis_brain]

there exists a tool called chopper XP
http://www.digital-digest.com/dvd/downloads/chopper.html

Use it for cutting out a short sample (2 to 10 sec)

and please: do NOT reencode the Video. Doing so can destroy the interlacing and blending, which we want to analyse.

[dogleg]

I had some problems with chopper xp...but finally I extracted something, but not the part i wanted :p. The times were messed up and chopper said that i was only 3 minutes of video in the vob when i was 10.

http://w1.314.telia.com/~u31433603/images/sample.zip

it's about 6mb

[scharfis_brain]

hehe, really weird NTSC->PAL conversion....
two different Telecine-Patterns within one frame at one time....

Dogleg, it is your decision, weather to deinterlace with interpolation (kerneldeint) or blending (fielddeinterlace).

kerneldeint makes a sharper image but maybe introduces stuttering due to the NTSC-> PAL conversion.

fielddeinterlace reduces this stutter but makes more ghosting...

[dogleg]

what is kerneldeinterlace?

I got better results with Telecide() than with fielddeinterlace().
I think almost all extras on PAL dvds are encoded this way :(

Can you give me some exampels of avs-code to try and compare with eachother?

[Mole]

You should also make sure if the extras are really in PAL format and not in NTSC.

I've come across a lot of PAL DVDs where main movie was PAL but all extras was NTSC.

[scharfis_brain]

@Mole: the sample from dogleg IS PAL.
And I absolutely doubt, that a PAL-DVD has NTSC extras. This would be
1) Non-Standard
2) Incompatible with a lot of TV-Sets

But those NTSC-extras are Converted to PAL via fieldblending. And this is shown very good with dogleg's sample.

Mole, can you count up some DVDs which contain PAL and NTSC on one Disk?

[Mole]

I live in Thailand and those DVDs are more intended for the local market. They were legit movies and not pirated.

The movies are US mainstream movies and B movies. I am not sure how they converted it to PAL, but the conversion was rather bad. The main movie were PAL, but extras such as trailers and behind the scenes were NTSC. I guess they didn't bothered to convert it.

And regarding your "absolutely doubts":

1. It all depends on the definition of "standard". The DVD standard clearly allows mixing NTSC and PAL content on one disc. So, I am not sure what you mean by "non standard". Maybe you should use the word "rare", or "strange", but it is clearly within standard.

2. Most PAL TV sets has no problems supporting NTSC signals as well. The problem is more with NTSC TVs which usually does not support PAL. Since the main movie on these discs is PAL, they are clearly intended for a PAL market. They probably saved some costs by not converting the extras with the assumption that most people has a multisystem TV, or in case not, it's not a big deal to not be able to view extras.

These discs were clearly aimed at the local low end market.
All zone 3 disc released by the studios that I have seen are all in NTSC.

[scharfis_brain]

1) really? Okay...

2) which is Thailand's TV-Standard? NTSC?

IMO here in Germany I'll never see a commercial mixed PAL/NTSC DVD...

[Mole]

It should be logic that since the PAL DVDs I'm talking about was intended for the Thai market, the TV standard in Thailand should also be PAL?? Or was it that difficult to understand?

IMO, Germany is not the only country in this world......
What you have never seen does not mean it doesn't exist.

[sh0dan]

@Mole: Don't get into insults! Otherwise strikes will follow!
scharfis_brain is asking legit questions and is trying to help you!

[Mole]

Umm, I haven't asked for any help and do not need it in this case either.

In my first post, I was merely pointing out about DVDs with both NTSC and PAL content. Then scharfis_brain was kindly enough to point out that surely my experience is wrong because according to his belives, DVDs with mixed PAL and NTSC content should not exist.

I took that statement and the tone in his thread as somewhat insulting to me, this is why I am replying to him in the same manner as he started his reply with me. And I see that first thing he does is to report to a mod....

[scharfis_brain]

And I see that first thing he does is to report to a mod....
I did not report anything to anyone...

And if someone feels personally affected, I am sorry. I cannot handle the english language that well...
So it sometimes sounds unfriendly, which isn't intended that way...

[Mole]

I don't know if it's about English.

But I think it is universal.

Think about if it was you who is telling about something you have experienced yourself. Then somebody comes and tells that it can not be true, because it is not logic and that person has never experienced it himself. How would you feel about it???

[scharfis_brain]

Since I have experienced VERY often users, that stated things I could not believe, And I was right after a loooog discussion, so I am doubting a LOT of things, which sounds weird to me.

I think this is a normal human behaviour...

I don't want to do a war about discussion-rules etc.

And Okay, this time, my opinion was false and my knowledge about the DVD-Standard not correct.

[Mole]

BTW, I looked at the sample, why not simply compress it as interlaced?

You'll lose either details or smoothness or maybe both if you try to de-interlace it.

The simplest and IMO best solution would just compress as interlaced.

[scharfis_brain]

hehe, this was my 1st thought, too...

But dogleg asked for deinterlacing advices, so I tried...

[Mole]

I'm also sorry that I accused you of reporting the post.

Glad we agree on something. :)

I think many people should start thinking that compressing as interlaced is quite an OK thing to do sometimes.

If the source is 100% interlaced, it is always best to re-compress as interlaced. The only time you would need to de-interlace is when you are compressing to a format which does not support interlace such as MPEG1 or DivX 3.11.

[dogleg]

I have tried encode it interlaced, the playback gets smooth but the quality becomes not so good, when I deinterlace I get better picture quality but the playback get a bit jerky.

I'm encoding in about 2000 kbit/s, if I had more space left on the dvd I would without doubt keep it interlaced.

What I really wanted to know was if I could recreate better progressive frames using something different than Telecide().

Maybe you should start a new thread and discuss whether you can or cannot have PAL and NTSC on the same disc.

Thanks for the help scarfis_brain :)

[Inc]

I'm encoding in about 2000 kbit/s, if I had more space left on the dvd I would without doubt keep it interlaced.

Interlaced Mpeg2 encodings do need MORE bitrate, thats why your output gots worse quality. 2000kbit/s in case of interlaced encodings at full height is too low! ;-)

[dogleg]

I agree :P

[scharfis_brain]

how would interlaced 352x576 Compress?
since it is Half D1, it should be quite Okay, when doing a multipass encode with a minBr < 400kbps and a maxBr > 4000kbps with an avgBr of 2000kbps ....
I've done some interlaced SVCDs even @ 480x576 with an avgBr of 1500 kbps.

It should look better than the deinterlaced 704x576

[dogleg]

I have no experience in svcd and rezising so I don't know :(

Does anyone know what happens if you encode a progressive stream as interlaced, would you get bad quality? I was thinking using Telicide(post=false,blend=false) then the frames that weren't successfully deinterlaced stay interlaced.

In other words make a mix of progressive and interlaced frames and play them as interlaced. Then I would get the good playback and better quality because some frames are progressive

[Mole]

Yes, interlaced encoding needs more bitrate to look better.

However, I would still say you lose more quality by de-interlacing it than keeping it interlaced.

Remember that there will always be either lost of detail or smoothness when you de-interlace a 100% interlaced material. Unless of course you do a Bob+Weave deinterlace as suggested in 100fps.com. But you'll end up with a 50 fps video, which is of course non standard for DVD or SVCD. It would only be useful for MPEG4 encoding.
Besides, at 50 fps, you'll also need to get higher bitrate than a 25 fps to get comparable quality.

IMO, the quality loss when de-interlace vs quality loss compressing as interlaced than progressive, is not worth it.
You'll lose quality doing it any of ways, but IMO, de-interlace process will hurt more than just keeping it as interlaced.

[scharfis_brain]

Forget about that idea!

telecide WILL make your NTSC->PAL - converted Video jerky and jumpy.
On PC-Monitor it may look fine sometimes, but not on TV, because it displays the fields in a serial order, while a PC displays two fields at the same moment.

So don't apply any kind of field matching (telecide, pfr, etc.) on this kind of stream.

If you want to resize the interlaced Video, just place a
crop(8,0,-8,0).Lanczosresize(352,576)
after the mpegsource-command.

Then load this AVS into your encoder (preferably Procoder or TMPGenc) and do your settings.

[Mole]

I agree. It's better to keep it interlaced, then resize to 352x576 and encode than de-interlace it and encode at 720x576.

On a TV, you won't probably notice the details lost by resize to 352 instead of 720. But I think you will certainly notice the jerkiness of any attempt on de-interlace.

PS. 352x576 is not SVCD resoultion. It is a perfectly valid DVD resolution, so your DVD authoring program will have no problems accepting it.

[Wilbert]

If you want to resize the interlaced Video, just place a
crop(8,0,-8,0).Lanczosresize(352,576)
after the mpegsource-command.

I guess you mean

separatefields
crop(8,0,-8,0).Lanczosresize(352,288)
weave

[dogleg]

I did a little test on my own, and used 6 different methods to encode this. The result I got after rezising was much better than any other method. One thing I don't understand is why it's important to crop before rezising. Why is that necessary?

[scharfis_brain]

@wilbert: since I do NOT alter the vertical size, a simple resizing without separating fields will work without problems.

@dogleg: you need cropping befor resizing to retain the correct Aspect ratio.

352 represents half D1
704 represents D1
720 represents Letterboxed D1

Your clip is 720 pixels wide. the half res. would be 360. but this isn't a valid DVD-resolution.
So you have either to do a crop before resize:
crop(8,0,-8,0).Lanczosresize(352,576)

or a crop after resize:
Lanczosresize(360,576).crop(4,0,-4,0)

Both lines do exactly the same.

when doing a direct resize from 720 to 352 without cropping, you'll get a Wrong Aspect-Ratio

[Inc]

Originally posted by scharfis_brain
[B]@wilbert: since I do NOT alter the vertical size, a simple resizing without separating fields will work without problems.
But a resizing everytime treats also the pixels as a whole "frame"-image, its like in Photoshop if you resize = a little blurring or in case of lanczos a little sharpen will occur.

[scharfis_brain]

But a resizing everytime treats also the pixels as a whole "frame"-image, its like in Photoshop if you resize = a little blurring or in case of lanczos a little sharpen will occur. If you have read the AVISynth carefully, you would know, that a resizer is internally built out of a horizontal and vertical resizer.

If I change the resolution in the horizontal directon (704x576 -> 352x576), only the horizontal resizer will be used. The vertical resizer will be passed by.

This means, that NO vertical blur can ever occur, when vertical res. is unchanged.

[Inc]

ok, I checked that! Thanks for the info.

[dogleg]

What happens if I resize to 720*288 to get rid of the interlacing and then encode it as progressive. It looks pretty good in virtualdub at least

[scharfis_brain]

720x288 is no valid DVD-resolution.

btw. resizing to 288 will result in the same like if you apply fielddeinterlace() (blending)

[Mug Funky]

hmm... just to throw some more confusion into the debate, i've found spacer clips (15 frame, or 1 GOP chapter clips) in NTSC on mainstream PAL releases.

gawd, i forgot which one it is. i'll have to look through my collection again. i only noticed because my TV is multiformat but blinks a bit when it switches between NTSC and PAL, and loses colour for a second. this will happen between special features, menus, at the end of a main feature (authors often put a blank GOP at the end of a feature for strange chapter reasons i can't quite recall now. something to do with last chapter skipping?). i've encountered at least 1 disc where the spacer used is NTSC and the feature is PAL.

i'm in region 4 by the way...

after looking at the clip, i think smartbobbing and unblending is the best way to get good results, but the clip is a killer - it was encoded as progressive, so there's uglies all over it. i tried my special smart bob script (it's experimental so i don't recommend it) and got okay results, but the noise level causes my bob to include some bizarre artefacts.

i'd put this one in the "you can't polish a turd" basket, and just run tomsmocomp on it. it's my favourite deinterlacer.

[scharfis_brain]

unblend would work maybe, if there is only one TC-pattern present.
but due to composing the video, the film has a other pattern offset, than the scrolling border. This will make it nearly impossible to unblend this clip successfully....