IVTC or Yadif?

[pooksahib]

I've started work on a PAL DVD with mouseteeth. "Bob" reveals movement every second frame and my notes say "...IVTC using TFM". Being curious, I ran the 'Analyse' function in MeGUI and it pointed me to Yadif. I did some googling on 'IVTC vs Yadif' and ended up reading about TempGauss. Said manono in 2009: "If quality and not encoding time is your main concern, then nothing beats TempGaussMC."

I installed TempGaussMC_beta2.avsi and the required plugins but couldn't get the script to run.

My questions then: Do I definitely NOT need QTGMC where movement is every two frames? Which to use: IVTC, Yadif or something else?

Many thanks.

[Alwyn]

Attach a sample.

TempGaussMC

That is (Q)TGMC. (Q for Quick).

[pooksahib]

Thanks, Alwyn. One lives, one learns... I did edits using Yadif and tfm (TIVTC) but can't tell the difference. I'll stick with Yadif solely based on another manono uttering: "Yadif is, in my opinion, the fastest good deinterlacer."

[manono]

Maybe the fastest, but far from the best. That must have been a long time ago I wrote that. I use a different fast bobber now.

And you don't IVTC a PAL video. TFM, maybe. And if TFM is the way to go, that produces better quality than any deinterlacer or bobber.

[pooksahib]

That was back in 2009, manono. Hello, by the way.
When I first used Bob() on this DVD it was a quite distinct 'movement every 2nd frame'. But I've done it again and don't really know what I'm seeing - it's kind of one step forward one step back but still moving forward (if that makes sense). Perhaps someone would be kind enough to look at this sample, explain HOW they analysed it and what's best to do with it when doing an avisynth edit. My grateful thanks.

[Sharc]

The video content is progressive, just flagged as interlaced, TFF, and phase shifted. Not unusual for PAL. Don't deinterlace but rather field-match it using TFM() and you will get the 25fps progressive frames.

LWLibavVideoSource("sample.MPG")
TFM()

[pooksahib]

Thank you, Sharc. I think I've been doing this wrong all along. I'd open the VOB's with MeGUI and look at the preview for combing thinking that no combing=progressive and combing=interlaced. This DVD does have combing so what is it you did to establish that it's "progressive, just flagged as interlaced, TFF, and field shifted"? Thanks again.

[Sharc]

Thank you, Sharc. I think I've been doing this wrong all along. I'd open the VOB's with MeGUI and look at the preview for combing thinking that no combing=progressive and combing=interlaced. This DVD does have combing so what is it you did to establish that it's "progressive, just flagged as interlaced, TFF, and field shifted"? Thanks again.

Separate the fields and step through the fields in 2 tests, using AviSynth:

AssumeTFF()
SeparateFields()

you will see motion with every 2nd field advancement only but motion is smooth, means it is actually progressive video

then using

AssumeBFF()
SeparateFields()

you will get your jerky forward-backward jitter motion. Means it is phase shifted.

[Alwyn]

Can be analysed easily in VDub; simply apply the Bob Doubler+TFF/BFF or Deinterlace filter (Yadif+Double Rate BFF/TFF), then step through.