Deinterlacing in 2024...

[wcndave2]

I started a few weeks ago capturing video to OBS, then got into the PAR/DAR, cropping and upscaling etc realm, and ended up looking into interlacing and found myself on digitalfaq, where on a guide to video capturing I read about interlacing, which ended with:

There are only a few situations where deinterlacing is even necessary

From what I can understand, the logic went like this...

• A TV will deinterlace very nicely, using dedicated processing.
• If you manually deinterlace, there will be some noise and you won't do as good a job.
• So don't do it, because you're going to be playing this on a TV...

I feel that this article must be out of date now, as anything I digitise will almost certainly be consumed on mobile/laptop/tablet/computer/online etc, or on a TV that is built for progressive images.

Certainly playing anything interlaced on every TV, computer, phone and device in my house displays obvious and very unsightly combing...

Is the general consensus now that deinterlacing during digitisation is necessary, and the reasons to avoid deinterlacing (everything is viewed on an old TV) no longer apply?

[dellsam34]

Yes slightly outdated, nowadays most videos endup in social media or modern devices including smart TVs, the de-interlacing task is poorly implemented/managed in them, they are all geared towards progressive videos including OBS, Capturing analog videos from tapes in the other hand hasn't changed, it has been and will always be as follows: Capture lossless and save these master files if important, de-interlace, crop or mask, resize, encode and share. Only the need to de-interlace has changed not how it's done.

There are automated methods where everything is done on the fly using software or hardware but the results are mediocre, good for a quick view but no at the archival standards, you wouldn't want to do that to your family videos.

[Bwaak]

All TV sets can handle interlaced video no matter whether they have a CRT or a progressive-scan panel. In the latter case, a TV will deinterlace. There are different deinterlacing schemes depending on the actual structure of the incoming signal, and some deinterlacers are better and smarter than other. Faroudja, DVDO, HQV were the buzzwords twenty years ago, when plasma TVs began replacing CRTs. The need for a good deinterlacer has not disappeared, as interlacing is still valid in broadcast TV.

On many DVDs, you get mixed content, with frame/field structure changing. This often happens when a film source was edited on video, and video effects and titles were added. A good TV set would switch modes fast enough for you not to see interlacing artifacts.

The catch is, a TV will not deinterlace a video if it thinks it is not needed. In my setup, interlaced video is marked as progressive, and it will not look good on TV. OTOH, my TV cannot play Cineform files anyway.

Modern computer video players either deinterlace automatically or have settings where you can switch deinterlacing on and choose deinterlacing scheme. For Windows, I like Splash, it is fast and high quality.

Youtube accepts interlaced content, but does not care to deinterlace it correctly, and treats it as progressive, weaving every pair of fields into one frame. For Youtube you must deinterlace, and you must upscale to at least 720p if you want 60p or 50p to kick in.

[wcndave2]

All TV sets can handle interlaced video

Except the vast majority of digital content is not viewed on a TV...

The catch is, a TV will not deinterlace a video if it thinks it is not needed

Out of the video creators hands...

Modern computer video players either deinterlace automatically or have settings where you can switch deinterlacing on

Out of the video creators hands...

Youtube accepts interlaced content, but does not care to deinterlace it correctly, and treats it as progressive

Out of the video creators hands...

So, I guess my point was, I feel that given how digital media works, is viewed, the devices, and the distribution.... that whereas that article says:

"you should never have to deinterlace, it's not needed", the modern take is
"you should always deinterlace, it's definitely needed".....

And I wanted to check if this feeling was a valid reflection of video capture and digitisation in 2024... I feel your answer is affirmative, whether you meant it or not

[wcndave2]

it has been and will always be as follows: Capture lossless and save these master files if important, de-interlace, crop or mask, resize, encode and share. Only the need to de-interlace has changed not how it's done.

Thanks, at the moment I have gone from OBS capture as mkv....
to
AmaRecTV with Huffy to "lossless" AVI, AvsPmod scripting, and still deciding between using the UI of VDub2 or copy/paste command line of ffmpeg to apply and render...

[dellsam34]

AvsPmod is more automated, you can QTGMC de-interlace, crop, resize and output with vdub2, When vdub2 pops up you can add your codec output, When you set everything up and satisfied hit the final processing button and go do other things, This is the way I do it, I get to use the best filters out there with high quality processing while doing it all at once.

The advantage of this method over ffmpeg script is that you get to visualize the video of every setting you apply of every step of the whole process, de-interlace, crop, resize, encode, each step can be previewed in real time with two video windows, before and after the setting is applied, it can't be any better than this.

[Sharc]

"you should never have to deinterlace, it's not needed", the modern take is
"you should always deinterlace, it's definitely needed".....

It's a personal decision eventually. Keep in mind that a deinterlacer synthesizes the missing field, means it creates something which is not in the original video. Even the 'best' filters are 'best' for the time being only. The quality depends entirely on the deinterlacer. When done poorly the damage is there, irreversible. For archiving keep the original interlaced capture. When file size matters you may want to go for a 'visually lossless' intermediate.
I kept my interlaced videos usually as interlaced. Noone has ever complained when watching these on a modern TV. Deinterlacing is however a must when one wants to resize vertically, like converting the SD interlaced video to 4:3 1440x1080 square pixel for example. Resizing vertically without deinterlacing damages the video irreversibly.
Also, many filters are designed for progressive video. Using these on interlaced footage is a bit more complicated.
Pro's and cons. Choose your poison.

[Bwaak]

So, I guess my point was, I feel that given how digital media works, is viewed, the devices, and the distribution.... that whereas that article says:

"you should never have to deinterlace, it's not needed", the modern take is
"you should always deinterlace, it's definitely needed"

FWIW, 12 years ago I converted my DV recordings from 480i30 into 720p60 H.264 using the then state of the art commercial software. I meant these files to be my new masters for whatever I would want to do with the videos. I still have the tapes. In all these years I have never watched these videos once. They could as well not exist. I have not yet delivered the final edit for the video I shot in 2008. Sure, everyone's situation is different. If you are going to watch them, then convert them into something that is watchable. Most people will not care for imperfect deinterlacing or a skipped frame. Should you keep the source footage? Most members of this forum would say "yes", I would have said the same five years ago. Today, I might say "dunno, maybe not". As Sharc said, it is a personal decision. Storage is cheap nowadays.

[Sharc]

So, I guess my point was, I feel that given how digital media works, is viewed, the devices, and the distribution.... that whereas that article says:

"you should never have to deinterlace, it's not needed", the modern take is
"you should always deinterlace, it's definitely needed"

FWIW, 12 years ago I converted my DV recordings from 480i30 into 720p60 H.264 using the then state of the art commercial software. I meant these files to be my new masters for whatever I would want to do with the videos. I still have the tapes. In all these years I have never watched these videos once. They could as well not exist. .....

Hehe. Quoting johnmeyer:
https://forum.videohelp.com/threads/413279-Which-of-these-two-different-ways-of-captur...e2#post2722370

[dellsam34]

It really depends on the culture, Usually in the west they don't care about their ancestors memories more than they care about what they will inherit. In my family we do watch old memories every now and then in social gatherings and I could see the impression on them about such good quality videos I produced, Some burst in tears when they see our old grandma, some would laugh about my passing father's jokes ...etc, So I don't let someone else's opinion on the internet dictates what I do with my family's memories.

[lordsmurf]

I started a few weeks ago capturing video to OBS,

That basically ruined it from the start.

[lollo]

About deinterlacing, the answer is always the same.

Today, a video watched on TV or on a Monitor must be deinterlaced by the TV or by the player. Or you can deinterlace in software, creating a progressive video, for example with AviSynth and QTGMC.

The choice between the 2 approaches is determined by who is doing a better job. And, unless you own a high end TV such as Sony A90J 4K OLED or similar that can match the software approach, the second is generally better.

[dellsam34]

I bought LG OLED 4k when they came out 5 years ago and supposedly geared towards videophiles with all that video processing power, guess what, they suck at de-interlacing, they suck even more when fed composite from a VCR, S-Video over HDMI is okay but not perfect.

[lollo]

My Sony A90J does not. Othh I still prefere QTGMC

[wcndave2]

"you should never have to deinterlace, it's not needed", the modern take is
"you should always deinterlace, it's definitely needed".....

For archiving keep the original interlaced capture.

Yes, I'll adjust my proposal to:

- For archiving keep interlaced
- For consumption, deinterlace

I started a few weeks ago capturing video to OBS,

That basically ruined it from the start.

I use OBS for it's intended purpose, and when I inherited a VHS player, figured it was an easy way to capture.

The main challenge was the AR/PAR etc... a lot of people were using HDMI converters, which does everything for you, and then re-squashing in OBS.

I found the capture device was giving me 720x576, so I cropped it to 704x576 and then stretched it to 768x576 which means it comes out as intended, and isn't doing anything more than the TV would have done anyway... (I don't get the resizing, you're only introducing more noise, which may be done better in 10 years, so keep it undistorted...)

In any case, the result from OBS was pretty good.

The installation and scripting for AVS is quite technical, and it takes a long time to render, and my WAF couldn't tell the difference unless it was pointed out... For many purposes, something like OBS is quick and easy, and may mean media is saved that would otherwise have been lost.

As a few people said, spending too much time on it, is just a waste of living time!

Thanks all!

[VHSvideocapture]

I didn't want want to start a new topic I do have some newbie questions please help as much as you can.
What is the best way to de-interlace? The most popular de-interlacer is QTGMC followed by Yadif.
For VHS capture upperfield first, lower field first, bob doube frame rate, other options included are blend fields, interpolate field.
Software for de interlacing for QTGMC Hybrid is a very good software and for Yadif Virtualdub has a bulit in filter.

Other ways to de-interlace are using your video editors like Sony Vegas, Adobe PP, BM Resolve
but from reading this very useful fourm, the experts on here advice against deinterlacing in video editors I think because thr video editor
Removes 1 field entirely?

I have tried de-interlacing in Yadif it works but its not clean if you guys can understand what I'm saying?
Hybrid with Avisynth does a very good because I use 2 video editors I don't know to export interlaced probably in Sony Vegas
when I render in Sony Vegas and import it to say Hybrid for QTGMC it does deinterlace but it plays with jagged lined or ghosting sorry I don't know the technical name for it, but if I capture in virtualdub dub, skip Vegas and take it straight to Hybird and use QTGMC with the same settings I get no issues, this means I'm doing something wrong in Vegas or Vegas is doing something to it?

[davexnet]

when I render in Sony Vegas and import it to say Hybrid for QTGMC it does deinterlace but it plays with jagged lined or ghosting sorry I don't know the technical name for it, but if I capture in virtualdub dub, skip Vegas and take it straight to Hybird and use QTGMC with the same settings I get no issues, this means I'm doing something wrong in Vegas or Vegas is doing something to it?

This is probably because either Hybrid didn't realize the file was interlaced, or Vegas didn't, resulting in improper handling.
You can use mediainfo to check the interlacing status of the file(s) as you go along

[VHSvideocapture]

This is probably because either Hybrid didn't realize the file was interlaced, or Vegas didn't, resulting in improper handling.
You can use mediainfo to check the interlacing status of the file(s) as you go along

Hybird uses media info the issue is lossless codecs don't flag interlacing correctly
This confuses the software, with hybrid you have the option to override input scan.

Does anyone know how to export interlaced in vegas? I keep the interlace settings
to 'none' normally upperfield first for lagrith and Huffyuv bottomfield first because it shows bottomfield first in hybrid media info.

If export it progressive then Hybrid does not de-interlace.

I tried both upperfield first and lowerfield first same results.

[JN-]

Does anyone know how to export interlaced in vegas?

In the Mainconcept MPEG-2 Render template you can select from the “Field order box.

[Alwyn]

Disclaimer: I don't use Vegas (or Hybrid). I deinterlace first, staying in AVI, then edit the progressive file in my editor. I suspect that workflow would get around the Vegas issues.

If you want to use QTGMC in Hybrid (I agree, easier than in AVISynth), the issue would be whether Hybrid outputs an AVI format that Vegas accepts.

[_Al_]

If you load progressive video to Hybrid and video is actually interlaced, you should tell Hybrid it is interlaced - Overwrite scan type

[Alwyn]

If you load progressive video to Hybrid and video is actually interlaced

That doesn't make sense.

[_Al_]

Apparently VHSvideocapture obtained video like that, so I post how to conform it in Hybrid.

[cibo]

If you load progressive video to Hybrid and video is actually interlaced

That doesn't make sense.

Welcome the world of media files, where mistagging, tools spitting out non-compliant files, lack of standardization, and poorly engineered programs is common place. I am not blaming the developers, datastream, especially video, is extremely complex and error-prone.
A progressive video can absolutely be, in fact, interlaced. Whatever it is through coding means (MBAFF, PAFF), or by wrong tagging in the datastream. Whenever you import a video in Hybrid, always check the scan type and override it as necessary. You can only trust your eyes.


Anyhow back on topic:
1. Always keep the original interlaced file
2. Deinterlace only for web distribution, or when you must conform a file to given requirements

[VHSvideocapture]

Does anyone know how to export interlaced in vegas?

In the Mainconcept MPEG-2 Render template you can select from the “Field order box.

But im exporting from lossless not the main concept template, im using the video for windows.avi windows in the vegas moviestudio templates lagrith shows as progressive. and Huffyuv shows as bottomfield first, so if I want to export it interlaced should I select upperfield for lagrith and lower field or HuffYuy? Would that not de-interlace it?

Also it has another option - de-interlace method options are : blendfields, interpolate fields, none I usually set it to none thinking its going to be interlaced, what confuses the day lights out me is what does ', reduce interlace flicker ' do?
Does it blend the fields or de-interlace because after selecting this I don't get jagged lines in Hybrid after de interlacing with Avisynth in hybrid, I just wanted ro ask the experts, is this the right thing to do?

[JN-]

But im exporting from lossless not the main concept template.

Ok, fair enough, I guess I didn't pay enough attention to all posts. Anyway I'm only familiar with Vegas Pro not Vegas Movie Studio that u are using.

[VHSvideocapture]

Disclaimer: I don't use Vegas (or Hybrid). I deinterlace first, staying in AVI, then edit the progressive file in my editor. I suspect that workflow would get around the Vegas issues.

If you want to use QTGMC in Hybrid (I agree, easier than in AVISynth), the issue would be whether Hybrid outputs an AVI format that Vegas accepts.

I do it the other way
Virtuldub lossless capture
Goes into Vegas clean up de-noise neat video save as lossless Lagrith file.

Then open that new lossless file in Hybrid de-interlace QTGMC resize if needed, then ask Hybird to output.h264 at my desired bitrate, this works very well only Vegas issue pops up because lagrith is not flagging interlaced its wrongly flagging progressive.

[rgr]

I do it the other way
Virtuldub lossless capture
Goes into Vegas clean up de-noise neat video save as lossless Lagrith file.

Then open that new lossless file in Hybrid de-interlace QTGMC resize if needed, then ask Hybird to output.h264 at my desired bitrate, this works very well only Vegas issue pops up because lagrith is not flagging interlaced its wrongly flagging progressive.

You can do all this in VDub -- Neat is also available there.

[lollo]

I do it the other way
Virtuldub lossless capture
Goes into Vegas clean up de-noise neat video save as lossless Lagrith file.

Then open that new lossless file in Hybrid de-interlace QTGMC resize if needed, then ask Hybird to output.h264 at my desired bitrate, this works very well only Vegas issue pops up because lagrith is not flagging interlaced its wrongly flagging progressive.

Wrong order of operations. Deinterlace first, filter after.

[rgr]

I do it the other way
Virtuldub lossless capture
Goes into Vegas clean up de-noise neat video save as lossless Lagrith file.

Then open that new lossless file in Hybrid de-interlace QTGMC resize if needed, then ask Hybird to output.h264 at my desired bitrate, this works very well only Vegas issue pops up because lagrith is not flagging interlaced its wrongly flagging progressive.

Wrong order of operations. Deinterlace first, filter after.

Neat can also filter interlaced video.