Field Deinterlace very slow

[The Belgain]

I'm encoding from an interlaced DVD source (X Files Season 2). I've tried using Fast Deinterlace, but the output is completely messed up: the top half of the output is the whole picture squshed vertically, and the bottom half is just garble.

Using Field Deinterlace, the output is very nice, however encoding speed is very slow (i used to get 20 fps first pass, 25 fps second on all other settings identical without deinterlacing; i now get 14 fps first pass, 16 fps second), is this normal?

My machine is an Athlon T-Bird 1000 @ 1150 with 256 MB DDR memory.

[jggimi]

Yes, it is.

From Hakko504's sticky thread in the dvd2avi forum:Deinterlacing is the process of removing interlacing effects from the picture. This can usually be done in one of three ways: 1) Removing one field and resize the remains to correct size, 2) SmartDeinterlacing, Compare the fields and if they differ too much in an area blend the fields together in that area. 3) Bob, separating the fields, doubling the framerate and resizing them back to original size. The name comes from the effect that you get if you don't make a line shift when you resize, because then the picture will bob up and down between each frame.I like Decomb for de-interlacing, the Telecide() option works very well for me.

[manono]

Hi-

You can put it down below Crop for a slight speed gain. But that figure doesn't sound out of line.

And are you saying that X-Files gets 20-25fps without FieldDeinterlace, or regular wide screen movies with the same horizontal resolution? Because I don't believe you'll get that kind of speed when encoding full screen material (without FieldDeinterlace) because there are more pixels to process. But I could be wrong.

[avih]

jggimi, there's a forth way, which is probably the best one. this a combination of #2 and #3. as in: separate the fields, but resize using information from the previous field, so you get double framerate, but not 'dumb' resize, but inteligent one that takes into account the details that remains from the prev field.

i have done it, but long time ago, and i don't remember the settings. sorry. but it's doable for sure.

cheers
avi.

[jggimi]

I thought Telecide does this automagically. From Doom9's guide -- the link brings up detail:Telecide (http://www.doom9.org/decomb-params.htm#telecide) recovers progressive frames by field matching and by default it will post process every frame and deinterlace parts of a frame where combing (interlacing) effects can still be found.

[The Belgain]

@manono: I do mean that i get 20 fps first pass, 25 second on the X-Files clip (4:3 ratio, 416x304). You are correct in saying that the speed is faster on a widescreen movie for the same horizontal res since there are fewer pixels, but for a clip at the same bitrate in widescreen, you would choose a higher horizontal res to have the same number of bits.

So what is the best way of doing deinterlacing using gknot (or another tool)? I can live with the speed loss, but it is quite annoying having the speed effectively halved :(

[jggimi]

A field de-interlace is doing twice the work; hence your speed is cut in half.So what is the best way of doing deinterlacing using gknot...Install Decomb filter from Doom9's server. From within GKnot, click on the Edit button in the window that pops up where you save the .avs file. Insert "Telecide()" after the plug-ins but before other filters. Manono says you could do it after the crop; ... you can test the avs in Vdub to see how it looks before encoding, or you could mash the Preview button in the same window after completing the edit. I prefer Vdub for preview, as I can go frame by frame with the right and left arrows.

[Ivion]

Originally posted by The Belgain
So what is the best way of doing deinterlacing using gknot (or another tool)? I can live with the speed loss, but it is quite annoying having the speed effectively halved :(

Well, first of all, do not expect me to be a expert on Deinterlacing, Teleciding (or however you may spell it :)) or IVTC.

The best way to deinterlace you say? Well if you only want to deinterlace, you have 2 choices depending on your source; Telecide or Field Deinterlace. If I remember correctly Field Deinterlace is for pure interlaced movies and Telecide for (as the name already suggests) Telecided movies (I could be terribly wrong here, correct me if I'm wrong :D).
Most PAL movies are pure interlaced types, as for NTSC, I do not know, because I've never worked with them (yet :)).

Hope this helpes.

BTW - I'm terribly sorry for all my spelling or grammar mistakes, please forgive me :)

I'm talking about using Decomb here, I strongly suggest you use that one, I think you will know how to use it, if not, check Doom9's guide (http://www.doom9.org/decomb.htm).

[jggimi]

I could be terribly wrong here...You're thinking of Telecine content. Similar spelling, but means something entirely different. Telecined content is NTSC video created from 24fps film... but that is not what Telecide is for.

What confuses many people between de-interlacing and Inverse Telecining (IVTC) is that they are both related to NTSC video. Depending on the video, though, you need neither, one or the other, or both.

What makes the confusion even greater, is that the Decomb filter set includes both de-interlace and IVTC filters. Telecide is a very smart de-interlacer.

I hope I haven't confused you completely.

[jggimi]

I've just heard from Manono. He has a correction on my interpretation of the Decomb filter set. :stupid:

[jggimi]

Manono wrote to correct me via private message. I've posted a few of his comments here...

This is just another example -- of many -- where a detailed review of the documentation may be helpful. It's also a good example of where I misread the doc.

Thanks, Manono!!

--------

... Quoting from the Decomb Help File:

"Telecide(): Recovers progressive frames but does not remove resulting duplicates and does not change the frame rate or frame count. Do not use Telecide on streams that do not contain telecined progressive frames, such as pure interlaced video."

...I've even tried to Telecide (pure interlace content) before. The result is that they are slightly jerky-not as jerky as if I had decimated them, but still noticeable. Why, you might ask? As near as I can tell, because Telecide is looking for Field matches, and incorrectly sometimes thinks it finds them, when there are none to be found. Quoting again, this time from an e-mail reply from neuron2 when I asked him about this very thing-why telecide didn't seem to be working well on a pure interlace source:

"Just remember that pure nonprogressive video does not require field matching. The video is just a series of independent FIELDS. Then they are paired into frames. There is no concept of field matching because each field is from an independent temporal moment. How can you match one to anything?"

And I always put Telecide-Decimate-FieldDeinterlace after the crop. it works every time...

[hakko504]

Originally posted by avih
jggimi, there's a forth way, which is probably the best one. this a combination of #2 and #3. as in: separate the fields, but resize using information from the previous field, so you get double framerate, but not 'dumb' resize, but inteligent one that takes into account the details that remains from the prev field.

This is called smart bob. Don Graft (neuron2) has written a VD filter that does exactly this. Or you can use this AVISynth script:Function GreedyBob(clip clip)
{
LoadPlugion("Greedyhma.dll")
video1=clip.Greedy(1,0,0,0,0,0,0,0)
video2=clip.Greedy(0,0,0,0,0,0,0,0)
return Interleave(video1,video2)
}

[Forumposter]

Actually I'm German and it's hard to understand..
It's not the English itself - it's hard to imagine how this could be and how it works.
I usually rip PAL Movies with 25fps. Some movies are "interlaced" (dvd2avi tells me).
Sometimes dvd2avi says they are interlaced - but I can't see any stripes.
And sometimes there are some stripes.. looks a bit like WinCommander 4 Cut Scenes.
All adult DVDs I ripped were always interlaced and because there's a lot of action in it, they get very visible :( (also PAL).

This time I have a NTSC adult DVD with a similar effect. While the PAL sources look a bit like errors.. this is even closer than a Cutscene in WinCommander with Mark Hamill.
To make clear, what I mean I wrote a screenshot.
http://www.URL-NOT.FOUND
Look at her mouth.

So - is this deinterlaced.. ? and what should I use? Decomb, Force Film, SmartDeinterlacer, Fast Deinterlacer, Field Deinterlacer?

And what about the PAL Movies (adult and non-adult). Which deinterlacer should I use?


Sorry for all my mistakes - but I'm tired - I will correct them tomorrow :)

[Ivion]

If I look to the screenshot, I see that it is Interlaced, but because it's a NTSC source, there's also a possibility that it is Telecided.

To check this, open your .avs without any deinterlace or ivtc filters. Then open it in Vdub, then you should go to a scene where there is alot of action. Then go through that frame by frame, if all the frames are interlaced, then you've got a interlaced source. If in a pattern of 5, 3 are interlaced and 2 are progressive, then you're dealing with a Telecided Source.

If Interlaced, use a Deinterlacer - "FieldDeinterlace()"
If Telecided, use IVTC - "Telecide()
Decimate(cycle=5)"

For PAL sources you should just use "FieldDeinterlace()".

Hopes this helps, if again, I'm babling again, please someone correct me. :)

[llemor]

@ The Belgian:

You can gain a little speed by using interpolation rather than blending in FieldDeinterlace(). You may want to edit your avs file and include blend=false in FieldDeinterlace function.

Quality-wise, of course blending gives you better quality. In my expericence, I tried to examine first the stream, if interlacing is not so much I used interpolation, otherwise I didn't change the default.

[jggimi]

I'm just now starting Atlantis. This one is a hybrid of fully progressive frames and interlaced frames. It says "FILM" in dvd2avi, but constantly switches between progressive and interlaced, rapidly.

I've run a few tests by excerpting small projects, 10-20 seconds worth of content, through dvd2avi, then went frame by frame with vdub.

1) Force FILM: It eliminated the interlaced frames. The results, though, had duplicated frames.

2) Decomb's FieldDeinterlace(): deinterlaced, but looked blurred

3) Telecide(): correctly rebuilt frames, with duplicates.
4) Telecide() w/ Decimate: Looked good, no duplicated frames.

I ended up using:

telecide(post=false, guide=1)
decimate(cycle=5)

Tests with that looked perfect.

[FreierGeist]

Hi all

i'm working on a 29.970 PURE Interlaced NTSC video and...
since it can't be IVTCed (i've already tried it) i'm trying to Deinterlace it
but i ain't got good results with FieldDeinterlace()
:(
the result comes "ghosty" (at motion scenes) and some parts of the movie becomes "blurry" (such as faces), but the interlaced parts' gone

i'll try the SmartDeinterlace
and then i put the results...

if someone have an ideia about the causes of the bad results i'll be very thankfull!

[]s

[manono]

Hi FreierGeist-

That's what FieldDeinterlace() does. It blends the 2 images together. It may not look so good when you look at it frame by frame, but it should look OK when played at full speed.

[llemor]

@ FreierGeist:

You can try to set blend=false in FieldDeinterlace() function to remove some ghosting. I've tried it already and the result is perfect. I learned it from hakko504. ;)

[FreierGeist]

@manono:
thank you very much (as always you're trying to help... i owe you a beer :) )!

but the the "ghosts" are very visible at (Windos)mplayer2.exe
:(


@llemor:
manono told me to try this some days ago...
and i haven't tried yet (i'm without time theses days...)

i'll try the blend=false and (if needed) the SmartDeinterlace

THANK YOU VERY MUCH!!!

[]s