Handbrake and interlaced question

[ultraman36]

Hey I wanted to know if when im converting my dvds to mp4 using Handbrake if I were to always set handbrake to deinterlace would that mess up dvds that are progressive? I have usually convert the movie first then check if it was interlaced by playing it back. Would my quality be effected any way if I always have deinterlaced on?

[manono]

Hey I wanted to know if when im converting my dvds to mp4 using Handbrake if I were to always set handbrake to deinterlace would that mess up dvds that are progressive? I have usually convert the movie first then check if it was interlaced by playing it back. Would my quality be effected any way if I always have deinterlaced on?

Yes, never deinterlace unless you're sure it's interlaced. And since movies aren't interlaced, never deinterlace movies, period. They might be hard telecined, so you IVTC. They might be field-blended, so you unblend. But don't deinterlace. Some deinterlacers can be set to deinterlace only if interlacing is found and to leave clean frames alone, but it's still a stupid idea to use a deinterlacer on a movie.

[usta]

I use MediaInfo to see if the files are interlaced. Only then I go ahead and check the deinterlace option.
To make things easy and fast, you can check the "Decomb" option and be done with it (this filter only deinterlaces frames that are visibly interlaced).

[manono]

I use MediaInfo to see if the files are interlaced.

Also a bad idea, especially for PAL movies on DVD, as they might have been encoded as interlaced but usually come from a progressive source. The best way to tell if something is interlaced is with your eyes. I repeat, deinterlacing something unnecessarily damages it.

To make things easy and fast, you can check the "Decomb" option and be done with it (this filter only deinterlaces frames that are visibly interlaced).

Decomb is an IVTC suite (Telecide/Decimate), or is it just being used here as a field matcher (Telecide alone)? If it's only matching fields (which might already be matched), it'll slow the encoding considerably, but won't do much damage to progressive frames. However, if deinterlacing is needed (like for interlaced video, and not for movies), there are much better deinterlacers than the FieldDeinterlace component of Decomb.

If Decomb is being used as an IVTC, the encoding will be much slower than necessary if the source is soft telecine (encoded as progressive with 3:2 pulldown applied), and you also take the chance of incorrect matches. Also, if the source is PAL you don't perform an IVTC.

[Smithcraft]

I agree with just turning on the decomb filter.

Here's the wikipage for Handbrake's deinterlace and decomb filters which can explain what all each option does and how, better than just cut and paste will.

http://trac.handbrake.fr/wiki/Decomb

SC

[manono]

I agree with just turning on the decomb filter.

I sure don't. But now I see what it is, so thanks for that. He stole the "Decomb" name from Donald Graft's Decomb IVTC, and is using techniques borrowed from Decomb, TIVTC and Yadif to deinterlace frames selectively. Still a very bad idea. If the source is hard telecined, or is a mix of hard and soft telecine, you run a full IVTC. Deinterlacing it in that fashion keeps it at 29.97fps (when it should be 23.976fps), and makes it play jerky. If the source is blended, you unblend it to the proper framerate (often 24.975fps, less commonly 23.976fps), and don't deinterlace it to 29.97fps which, again, makes it play jerky, as well as making it blurry. Only if the source is shot on video and is pure interlaced 29.97fps do you apply a deinterlacer. And then you deinterlace everything (pretty much, although I suppose you could then use its "Decomb" technique, resulting in much slower encoding). No, the only way to tell what you have is to examine it with your eyes and then apply the correct filter. One filter definitely does not fit all.

AutoGK can do a much better job than Handbrake does using this "Decomb" filter, although AutoGK can't handle blended sources properly. Is this Handbrake guy from a PAL country? Does he not know what an IVTC is? Or are there other ways to implement an IVTC within this program?

[jagabo]

And deinterlacers that claim to only deinterlace combed frames often make mistakes. They will occasionally deinterlace progressive frames, and occasionally let combed frames through untouched.

[Smithcraft]

I prefer to use it as it's a one stop shop for conversion. Plus when you come across content that jumps from progressive to interlaced and back, it can be less than satisfying to have an encode that is deinterlaced, rather than selectively deinterlaced.

AutoGK may work great for you, but it won't work for me.

SC

[manono]

I prefer to use it as it's a one stop shop for conversion.

Sure, if you like inferior results. Maybe you just didn't understand what jagabo and I were saying. Is it even possible to get 23.976fps results from NTSC movies when using this program? Or are all of your encodes 29.97fps? If a movie and 29.97fps, open one of them in something where you can advance a frame at a time (VDub(Mod), Media Player Classic (Home Cinema), etc.) go to a place with movement and start advancing a frame at a time. Do you get a duplicate frame in every 5 frames?

AutoGK may work great for you, but it won't work for me.

I don't use AutoGK. I first inspect the source and then do what has to be done in my own AviSynth scripts. I was just saying that for all-in-one apps, it does a much better job than does Handbrake at dealing with different sources (soft telecine, hard telecine, interlaced video). Because AutoGK is for conversions to AVI, and Handbrake does all kinds of conversions, then you're right that Handbrake is more of a one-stop-shop. As far as that goes, though, XviD4PSP can do anything Handbrake can do and more. Except that you actually have to know something for optimum results.

[nymph4444]

I was going to also use Decomb in Handbrake and leave it ON all the time. Because it only does it if it sees interlace.

So then I was going to set the De Interlace dropdown box to OFF.

But Handbrakes forum told me that even if De Interlace is OFF it will still have Interlace artifacs.
And then they told me that it still will De Interlace or something like that?

[Smithcraft]

In theory, if you use Decomb, Handbrake will only do the de-interlacing when it sees interlacing.

If you turn on the Deinterlacing, it will deinterlace everything, whether it is interlaced or not.

SC

[edDV]

Is this Handbrake guy from a PAL country? Does he not know what an IVTC is? Or are there other ways to implement an IVTC within this program?

The core of the team is French.

Handbrake does have a "Detelecine" filter explained here.
https://trac.handbrake.fr/wiki/Telecine

Quote manual...

HandBrake uses a detelecine filter called pullup (because it's the opposite of
pulldown). It's a very advanced inverse telecine filter from the MPlayer
project.

With all filters off, it does a weave for interlace source*. Interlace source can have "Detelecine", "Deinterlace" (Yadif) or "Decomb" filters applied.

One needs to examine the source for telecine pattern. There is no autodetection.


* Handbrake does not offer an x264 interlace (MBAFF) option.

[edDV]

And then they told me that it still will De Interlace or something like that?

If the source is interlace and all filters are set to off, it will do a simple weave.

Bottom line you need to examine the source before applying the appropriate filter.

[nymph4444]

What would happen if I set De Interlace to OFF in the dropdown list and then turned Decomb to OFF??

[edDV]

What would happen if I set De Interlace to OFF in the dropdown list and then turned Decomb to OFF??

see my response in your other thread.
https://forum.videohelp.com/threads/334839-interlace-help/page8?p=2084384