when to IVTC

[AdeptEnc]

I have serisouly read about ten guides in the last month - all Xvid to .avi encoding - and I have one question that NO ONE talks about... IVTC and Deinterlacing. I have read the IN-DEPTH IVTC INFO here on doom9 and I understand it fine, but none of the guides explain HOW to use them. This is what I have gathered... in DGIndex, if it reports Film 95% or higher - use force film = IVTC and Deinterlacing are COMPLETELY unnecessary.

I have figured out that I always need to use a deinterlace filter when DGIndex reports NTSC Interlaced. I use the smart filter for Vdub found here (http://neuron2.net/ ) -it seems to work very well, although I don't have much to compare it with and when you use it there are all these settings which I just leave alone because I don't know what they do (...any better suggestions for deninterlacing?).

I thought if it was NTSC Interlaced, that I would ALWAYS need to IVTC my project - this is not true. I encoded some skateboarding dvd's - when I used IVTC (TmpgEnc) they came out choppy - the frames should NOT have been removed... when I simply deinterlaced them with that filter in Vdub in my final pass - they came out fine. Also, I encoded some 25 minute episodes that were NTSC Interlaced - same thing - they came out choppy, but less noticeable because less action - but sometimes when the camera would pan, you can see the choppiness that resulted from IVTC. So, I don't think I should have IVTC'ed them either (I know for sure not to IVTC the skate vids).

So, I think I have 3 questions for you:

*If you analyze your vob's in DGIndex and they are film > 95% - force film. If they are NTSC Interlaced - when do you know if you need to IVTC them??

*If you don't need to IVTC those files - when DO you EVER use IVTC??

*IF you do IVTC, what program/method do you recommend??

Thanks SOOO much for any help

[malkion]

1) If interlaced and 29.970fps IVTC

2) See 1

3) VDud(Mod) and AviSynth. Decomb and KernelDeint filters. :D

[AdeptEnc]

Thanks for the reply. I don't mean at all for this to sound rude, but I don't think you understood my email...

I know if it is interlaced and 29.970fps that you SHOULD IVTC, but ALL my efforts (MANY) so far have pointed to the contrary - these are two examples of why:

1. Skate dvd = interlaced and 29.970fps = IVTC = VERY VERY CHOPPY (looks horrible). RE-encode with NO IVTC = nice encode.

2. Curb Your... (25 minutes episodes) dvdrip = interlaced and 29.970fps = IVTC = good looking, BUT I can still see choppiness where frames were taken out (especially when the camera pans) - making it seem like I should not even IVTC with these episodes.

The skate dvd definitely cannot be IVTC'ed - I don't know why - maybe because it was shot with video and transfered straight as video, so you shouldn't take any frames out??

The episodes I don't know about - I will try Decomb and KernelDeint filters - I was previously using Tmpgenc for IVTC.

THANKS SO MUCH for the help!

[manono]

Hi-

and I have one question that NO ONE talks about

Well, that's exactly what the DVD2AVI/IVTC/Deinterlacing Tutorial (http://www.doom9.org/ivtc-tut.htm) talks about. I'm assuming that's one of the 10 guides you've read.

I have figured out that I always need to use a deinterlace filter when DGIndex reports NTSC Interlaced.

Sometimes you IVTC, and sometimes all you can do is to deinterlace, so what you said is incorrect. DGIndex is only reporting how it was encoded, and not what it truly is. Both truly interlaced material, like your skateboard vids, and film telecined prior to encoding, will be reported as Interlaced. But the telecined material can be successfully IVTC'd. How can you tell the difference? One way is to put on a Smart Bobber (double-rate deinterlacer) such as KernelBob(Order=1), from Leak's improvement on neuron2's KernelDeint, or TDeint(order=1,Mode=1) from tritical's Tdeint, to make the framerate 59.94fps, instead of 29.97fps. Open it in VDubMod. If there's movement in every frame, it's truly interlaced material. If it's been telecined, and can be IVTC'd, then you'll see 2 identical frames in a row, followed by 3 identical frames in a row, evidence of 3:2 pulldown (telecine) having been applied. Another way is to open a non-Force FILM (29.97fps) Movie.d2v from DGIndex in GKnot, and if every frame is interlaced, then it can only be deinterlaced. If you see a pattern of, out of every 5 frames, 3 are clean progressive frames, and 2 are interlaced frames, then it can be IVTC'd.

*If you analyze your vob's in DGIndex and they are film > 95% - force film. If they are NTSC Interlaced - when do you know if you need to IVTC them??

If DGIndex reports it as greater than 95% FILM, then it's not interlaced, it's film. Ordinarily you can use Force FILM, and be done with it. No IVTC or deinterlacing needed.

*If you don't need to IVTC those files - when DO you EVER use IVTC??

Exaplained above. You have to first determine if telecine has been applied and you can use IVTC, or if it's been shot using video cameras and has to be deinterlaced.

*IF you do IVTC, what program/method do you recommend??

I recommend either Decomb or SmartDecimate for IVTC. I recommend either KernelDeint or Tdeint (better, but slower) for deinterlacing.

I recommend that you NOT use the IVTC in TMPGEnc. It's obsolete and very slow. Use an AviSynth script and encode in VDubMod instead.

[AdeptEnc]

this quote here I can understand:

"Another way is to open a non-Force FILM (29.97fps) Movie.d2v from DGIndex in GKnot, and if every frame is interlaced, then it can only be deinterlaced. If you see a pattern of, out of every 5 frames, 3 are clean progressive frames, and 2 are interlaced frames, then it can be IVTC'd."

Thank you, this is the first place/wording I've been able to understand. The first option that you wrote above it is WAY over my head - I only know BASIC script writing in avisynth.

thanks again

[AdeptEnc]

about that same quote - is there any other program (simple style like the quote) that I could do this in besides GKnot?? I only ask because I don't use GKnot.

Thanks!!

[PiXuS]

@AdeptEnc

Sorry to sound rude AdeptEnc, but you created the "Xvid vs Divx" thread where you start with a similar "I read all the guides in the entire universe in the last 10 years" and yet ask whether you should use MEDIA or H.263 quantization type, etc.

Now, you ask about IVTC... manono already pointed you to a guide that explains everything in great detail. The documentation in the Decomb package also helps a lot.

Conclusion: I can't believe you did read all these guides. If so and you STILL don't get it.. maybe you should stick to AutoGK and be done with it.

Sorry if I am being rude.. I am no moderator but... anyway.. I found it odd.

[manono]

Hi-

is there any other program that I could do this in besides GKnot??

Most people learning to encode go through a GKnot stage at some point, and have it on their computer. Some people (including myself) continue to use it for some of the pre-encoding chores even after they become competent encoders. Even today I still use it for getting some of the information I need for the .avs, such as the mpeg2source line, the cropping and resizing, getting the bitrate, and for helping to determine what kind of source material I have (Interlaced, IVTCable, PAL to NTSC, field blended 24->30fps, silent film framerate, etc). But since you're so well versed in the ins and outs of AviSynth, then set up some variation of this script:

LoadPlugin("C:\Path\To\DGDecode.dll")
Mpeg2Source("C:\Path\To\Movie.d2v")

and open it in VDubMod.

PiXuS-Yeah, I almost recommended in my first response that he start with AutoGK, at least until he learns his way around encoding. But I decided not to. It's like jumping into the deep end of the pool, without knowing how to swim. If he doesn't drown first, it's a good way to learn to swim. So, if he doesn't give up out of sheer frustration, it's a good way to learn how to encode. Don't you have to admire someone brave enough (or stupid enough) to go about it that way? In addition, anyone that doesn't read the wealth of guides around here for encoders, experienced and inexperienced, kind of deserves what he gets. But this IVTC-Deinterlace-DGIndex stuff isn't exactly easy to understand. And I do think you were a bit rude. :) No harm done. AdeptEnc is thick-skinned. :)

[AdeptEnc]

[QUOTE][i]Originally posted by PiXuS

Sorry to sound rude AdeptEnc, but you created the "Xvid vs Divx" thread where you start with a similar "I read all the guides in the entire universe in the last 10 years" and yet ask whether you should use MEDIA or H.263 quantization type, etc.

...

First, yes I said I read a lot of guides - I have and it is very frustrating. Second, yah I started some threads - because I have read a lot guides and they do not explain some of these topics. Third, I NEVER asked whether I should "use MEDIA or H.263 quantization type". Fourth, I started all 3 threads at the same time.

Finally, as far as your 'entire universe in the last 10 years' comment... people like you should just die.

[manono]

Hmmm... not so thick-skinned after all. Take it easy, guys. If I fanned any flames, then I apologize. And you, PiXuS, if you respond, be careful how you do it as, from my point of view, you started it. Maybe a review of Rule 4 (http://forum.doom9.org/forum-rules.htm) might be in order.