Deinterlace and IVTC

[anonymous83]

I'm learnig how to use avisynth to create scripts to use in vDub to encode my movies. But i'm experiencing some problems, so i'm searching for help here.
Infos about the movie (VOBS):
Frame Rate: 29.970fps
Video Type: NTSC
Frame Type: Interlaced

Wich is the best way to IVTC it? Using the Force Film option from DVD2AVI/DGIndex or using a filter from avisynth?
And the best way to deinterlace the movie? I was trying to deinterlace it using the Weave+Bob (VDub filters) "example" shown in this site (http://www.100fps.com), but after encoding i'm getting a avi file with 59.941fps :(

Sorry for my bad english :rolleyes:
Thks

[phin]

I'd like to know about these things as well. Several of the guides mention something to the effect of "See below for more information about IVTC" but I swear there isn't another mention of it. This appears in the DVD2AVI guide and another one that I can't think of at the moment.

[stickboy]

Originally posted by anonymous83
Wich is the best way to IVTC it? Using the Force Film option from DVD2AVI/DGIndex or using a filter from avisynth?I don't think DGIndex (nee dvd2avi) does much analysis on the content of frames. If it reports the frame type to be interlaced, that means the MPEG2 video stream doesn't have the flags necessary to recover the progressive frames, and therefore the Force Film setting won't be effective.

If you need to perform an IVTC operation (are you sure you need to?), use Decomb (http://www.neuron2.net/decomb/decombnew.html).

[anonymous83]

Originally posted by stickboy

If you need to perform an IVTC operation (are you sure you need to?), use Decomb (http://www.neuron2.net/decomb/decombnew.html).

I thought that when a movie has 29.970fps we should IVTC it to 23.976. I'm right or I'm confused :confused: ?

[Boulder]

Decomb.dll includes Telecide() and Decimate() which you can use to do the IVTC. Read the docs inside the package, there's a good tutorial there.

EDIT: You might be able to use Force Film in DGIndex to recover the progressive frames. Create the d2v project file, open it to Notepad and scroll down to the very bottom. If you see it's 95% or more FILM, use Force Film, otherwise IVTC.

[Chainmax]

I second that. Decomb's readmes and tutorial are excellent and you will learn pretty much everything you need to know about IVTCing. I would rather use TDeint (http://forum.doom9.org/showthread.php?s=&threadid=82264&highlight=TDeint) for deinterlacing and TIVTC (http://forum.doom9.org/showthread.php?s=&threadid=82264&highlight=TDeint) for IVTCing.


P.S: not all 29.97 movies are telecined, some of them are just interlaced.

[actionman133]

Originally posted by anonymous83
I thought that when a movie has 29.970fps we should IVTC it to 23.976. I'm right or I'm confused :confused: ?

not all 29.97 fps material is film (which is when you use IVTC). many times it is also video, which should stay at 29.97 fps. the way to find out, is to open it up in some video player, virtualdub would be amongst the best.

scan through it frame by frame. if you see 3 whole frames, followed by 2 interlaced frames (horizontal scan lines), then it is film and use IVTC. if each frames has lines in it, then it's video, in which case, you can't ivtc. you have to bob it (producing 59.94 fps video) and select even or odd frames (reduce it down 29.97 fps again).

eg.


Bob () # or use a higher quality bobber, like dgbob, or kerneldeint
SelectEven ()


good luck!

[Boulder]

Originally posted by actionman133
if each frames has lines in it, then it's video, in which case, you can't ivtc. you have to bob it (producing 59.94 fps video) and select even or odd frames (reduce it down 29.97 fps again).

eg.


Bob () # or use a higher quality bobber, like dgbob, or kerneldeint
SelectEven ()


good luck!
No, that's not the way to deinterlace. That means you're throwing away the other field completely which means much detail is lost.

If you absolutely must deinterlace, use a specific deinterlacer such as TDeint or (Leak)KernelDeint. If you encode to MPEG2 for DVDs, encode as interlaced, do not deinterlace.

[anonymous83]

Thks for your help. I learned a lot with your posts
I'm practicing with DComb and TDeint, searching for the best config for this encode.
And, my movie was not telecined, so i don't need to IVTC it, It will stay in 29.970 ;). Thks for teaching me this :)