Using QTGMC on Progressive causes wobble?

peridian · 23rd December 2012, 23:47

Hi,

I'm trying to encode all my DVDs to mp4. In particular I'm keen to try and keep the result as clean as possible, so that when it gets resized onto LCD screens of a higher resolution, they don't become too unsightly to watch.

To that end, I'm using Avisynth + VirtualDub. My script is QTGMC based, and works pretty well on interlaced DVDs. Some, however, are progressive to begin with.

I read somewhere that using:

QTGMC(Preset="Medium", InputType=1)

Would allow me to use QTGMC on a progressive input, but gain some of the cleaning that QTGMC does (e.g. degrain/denoise).

I tried it, and at first I thought it was doing a good job, but then I noticed (particularly on outdoor shots or where credit overlays were being shown) this strange kind of "wobble" in the image, almost like a heat haze effect.

It doesn't do this on interlaced input. Is this a property of using it on progressive?

Is there a way I can use QTGMC to do some cleaning of progressive without this wobble? Or do I need to look at doing the cleaning through alternate function calls?

I've tried using things such as dfttest (blew up), fft3dfilter (seems to have a slightly less pronounced form of the same problem), and no cleaning at all.

I just can't help but feel the output might be better and that QTGMC has the relevant settings built in to achieve this.

Any help would be appreciated.

Regards,
Rob.

aegisofrime · 24th December 2012, 01:18

Not sure what's the cause of the wobble, as it has never happened to me (although I usually use Preset "Slower"), but you coould try using

Code:

QTGMC(Preset="Medium").SelectEven()

and see if that helps.

peridian · 27th December 2012, 15:14

Quote:

Originally Posted by HolyWu

InputType is meant for dealing with badly deinterlaced progressive sources with horizontal shimmering/artefacts. If your progressive sources don't contain that problem, I think you should try some MDegrain-based scripts like SMDegrain or MCTemporalDenoise and tweak the settings.

Ah, okay, thanks for the tip about InputType. Given this is progressive from a DVD, it's not really bad quality to start with, I just wanted to try and keep it clean when I upscaled it.

Looking at SMDegrain for now, see what I can do with it.

Cheers,
Rob.

23rd December 2012, 23:47	#1 \| Link
peridian Registered User Join Date: May 2007 Posts: 10	Using QTGMC on Progressive causes wobble? Hi, I'm trying to encode all my DVDs to mp4. In particular I'm keen to try and keep the result as clean as possible, so that when it gets resized onto LCD screens of a higher resolution, they don't become too unsightly to watch. To that end, I'm using Avisynth + VirtualDub. My script is QTGMC based, and works pretty well on interlaced DVDs. Some, however, are progressive to begin with. I read somewhere that using: QTGMC(Preset="Medium", InputType=1) Would allow me to use QTGMC on a progressive input, but gain some of the cleaning that QTGMC does (e.g. degrain/denoise). I tried it, and at first I thought it was doing a good job, but then I noticed (particularly on outdoor shots or where credit overlays were being shown) this strange kind of "wobble" in the image, almost like a heat haze effect. It doesn't do this on interlaced input. Is this a property of using it on progressive? Is there a way I can use QTGMC to do some cleaning of progressive without this wobble? Or do I need to look at doing the cleaning through alternate function calls? I've tried using things such as dfttest (blew up), fft3dfilter (seems to have a slightly less pronounced form of the same problem), and no cleaning at all. I just can't help but feel the output might be better and that QTGMC has the relevant settings built in to achieve this. Any help would be appreciated. Regards, Rob.

24th December 2012, 01:18	#2 \| Link
aegisofrime Registered User Join Date: Apr 2009 Posts: 478	Not sure what's the cause of the wobble, as it has never happened to me (although I usually use Preset "Slower"), but you coould try using Code: QTGMC(Preset="Medium").SelectEven() and see if that helps.