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Old 5th December 2011, 02:26   #1001  |  Link
ihhm
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Can anyone please help me find a way to eliminate the vertical shimmers in this clip?

Sample clip:
http://www.mediafire.com/?zc2egghbal2vb11

The shimmers are most visible on the vertical lines of the window blind and cabinets. I even tried the preset "Placebo", but the shimmers are still there. Please pardon my ignorance if these are not called shimmers as I just started learning about encoding. I am still finding my way around MeGUI, QTGMC and Srestore.
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Old 5th December 2011, 10:11   #1002  |  Link
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I get these weird vertical lines (clearly visible in the clouds). Anybody have any recommendations for getting rid of 'em?
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Old 5th December 2011, 23:43   #1003  |  Link
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thanks for your great work on this awesome script.
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Last edited by bluered1; 7th December 2011 at 21:40.
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Old 6th December 2011, 00:21   #1004  |  Link
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ihhm: QTGMC can deal with horizontal shimmering effects, but not really the vertical problems that clip is showing. It's not even a shimmer really, being rather occasional...?
Mr Alpha: Similarly, that doesn't initially look like anything to do with QTGMC, but I can't tell without seeing a short clip of the affected source.
bluered1: You're welcome.
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Old 6th December 2011, 03:04   #1005  |  Link
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Vit, thank you for your reply. I will start a new thread outside of QTGMC to see if other filters can help.
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Old 6th December 2011, 10:43   #1006  |  Link
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Quote:
Originally Posted by -Vit- View Post
Mr Alpha: Similarly, that doesn't initially look like anything to do with QTGMC, but I can't tell without seeing a short clip of the affected source.
There is definatly a hint of the same pattern in the noise in the source, but it looks to me like rather than removing the noise QTGMC stabilizes it. Here is a 10sec piece of the source.
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Old 6th December 2011, 21:46   #1007  |  Link
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That's a messed up source. The last shot is progressive and needs no deinterlacing. The first shot looks interlaced, and the top fields are fine, but the bottom fields are just a blend of the current and next frames (i.e. they do not contain a new temporal frame). I think the middle shot (from which your screen cap is taken) is the same. Then there's that fairly strong noise, over a detailed image.

You're not going to get double rate out of this, so QTGMC may not be the correct approach, although it does even out the differences in the fields - you'll want a SelectEven afterwards.

The frame blending means the noise has a temporal echo, which may fool any temporal denoising into thinking it's not noise, meaning you need a stronger denoise that you would expect. A spatial denoise of sufficient strength will destroy the detail. Also the temporal processing of QTGMC is reinforcing the issue, leaving you with that fairly stable grain. Really this needs a more customized repair job, beyond the scope of QTGMC. Within the QTGMC settings you might want to set TR1=1 and TR2=0 (or 1), to reduce the temporal processing of QTGMC and stop the grain from being stabilized. That will leave you with more noise to get rid of though...

Last edited by -Vit-; 6th December 2011 at 22:01.
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Old 7th December 2011, 12:40   #1008  |  Link
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Quote:
Originally Posted by -Vit- View Post
That's a messed up source. The last shot is progressive and needs no deinterlacing. The first shot looks interlaced, and the top fields are fine, but the bottom fields are just a blend of the current and next frames (i.e. they do not contain a new temporal frame). I think the middle shot (from which your screen cap is taken) is the same. Then there's that fairly strong noise, over a detailed image.

You're not going to get double rate out of this, so QTGMC may not be the correct approach, although it does even out the differences in the fields - you'll want a SelectEven afterwards.

The frame blending means the noise has a temporal echo, which may fool any temporal denoising into thinking it's not noise, meaning you need a stronger denoise that you would expect. A spatial denoise of sufficient strength will destroy the detail. Also the temporal processing of QTGMC is reinforcing the issue, leaving you with that fairly stable grain. Really this needs a more customized repair job, beyond the scope of QTGMC. Within the QTGMC settings you might want to set TR1=1 and TR2=0 (or 1), to reduce the temporal processing of QTGMC and stop the grain from being stabilized. That will leave you with more noise to get rid of though...
If the frame blending is what is causing the issue, would it make sense to do it like this:
  1. First run QTGMC with TR1=1 and TR2=0, but without any denoising at all,
  2. then run SelectEven to get rid of the blended frames,
  3. And lastly run a separate denoiser on the remaining even fields, thus hopefully avoiding the temporal echo?

A side question: What about crop? Would it make more sense to move crop to before QTGMC and thus save me some pixels to process, or would that interfere with QTGMC?

Last edited by Mr Alpha; 7th December 2011 at 12:43.
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Old 7th December 2011, 14:02   #1009  |  Link
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Quote:
Originally Posted by Mr Alpha View Post
If the frame blending is what is causing the issue, would it make sense to do it like this:
  1. First run QTGMC with TR1=1 and TR2=0, but without any denoising at all,
  2. then run SelectEven to get rid of the blended frames,
  3. And lastly run a separate denoiser on the remaining even fields, thus hopefully avoiding the temporal echo?
Yes that seems reasonable. There will still be a little blending in the result since QTGMC fundamentally relies on some temporal processing. Still it's better than completely discarding the blended frames, since they contain genuinely new spatial data, even if it is blended.

Quote:
Originally Posted by Mr Alpha View Post
A side question: What about crop? Would it make more sense to move crop to before QTGMC and thus save me some pixels to process, or would that interfere with QTGMC?
Yes, that's fine.
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Old 10th December 2011, 05:30   #1010  |  Link
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Quote:
Originally Posted by -Vit- View Post
Adding resizing at all is rather pushing the feature envelope of QTGMC and gamma-aware resizing has never really caught my interest, but I'll make a note to have a look...
I'm starting to look into upscaling with NNEDI3, as highlighted in this thread.

e.g.
Code:
#720x576 interlaced source
QTGMC()
NNEDI3_rpow2(rfactor=2, cshift="spline36resize", fwidth=1280, fheight=720)
Is this sensible, or is there a smarter way to integrate this type of resizing with the deinterlacing, since QTGMC uses NNEDI3 anyway?

-Vit-, if you are considering including resizing in a future version of QTGMC, is this something you could look at instead of, or in addition to the more basic resizers?
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Old 10th December 2011, 14:56   #1011  |  Link
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Quote:
Originally Posted by nhope View Post
Code:
#720x576 interlaced source
QTGMC()
NNEDI3_rpow2(rfactor=2, cshift="spline36resize", fwidth=1280, fheight=720)
Is this sensible, or is there a smarter way to integrate this type of resizing with the deinterlacing, since QTGMC uses NNEDI3 anyway? ... if you are considering including resizing in a future version of QTGMC, is this something you could look at instead of, or in addition to the more basic resizers?
That is my preferred method of upscaling by far. If upscaling makes it into QTGMC it will be via some NNEDI3-related method.

Last edited by -Vit-; 10th December 2011 at 15:00.
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Old 13th December 2011, 09:51   #1012  |  Link
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Is it possible to use it to convert from 50i to 25p interpolating adiacent frames?
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Old 13th December 2011, 11:39   #1013  |  Link
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Quote:
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Is it possible to use it to convert from 50i to 25p interpolating adiacent frames?
Yes of course, it's the main purpose of this awesome script!
Please read the first post and included documentation for details.
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Old 13th December 2011, 14:04   #1014  |  Link
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Quote:
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Yes of course, it's the main purpose of this awesome script!
I have to disagree, the main purpose is to bob-deinterlace interlaced content which means the result has double the frame rate of the source.

There are no "adjacent frames" that need to be interpolated. It's actually the other way around, if you want to stay with the source frame rate, then you are throwing away 50% of the available temporal information (every other bob-deinterlaced frame is discarded). As a consequence, with most videos, especially ones with fast and/or shaky motion, this will lead to a stroby looking video. QTGMC offers the option to add motion blur to aid this but still it's naturally very recommendable to go with the double rate output if there's no particular reason not to (like YouTube).

Last edited by TheSkiller; 13th December 2011 at 16:07.
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Old 14th December 2011, 19:17   #1015  |  Link
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Quote:
Originally Posted by TheSkiller View Post
I have to disagree, the main purpose is to bob-deinterlace interlaced content which means the result has double the frame rate of the source.
No, I want to go from 50i to 25p (with same speed, obviously). I did hope in something to use both fields, not only one.
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Old 14th December 2011, 20:54   #1016  |  Link
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tormetno, 1st example in 1st post of this thread:

Code:
YourSource("yourfile")    
QTGMC( Preset="Slow" )
SelectEven()
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Old 14th December 2011, 23:52   #1017  |  Link
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Quote:
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tormetno, 1st example in 1st post of this thread[/CODE]
Does it take two fields in consideration or only one?
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Old 15th December 2011, 00:03   #1018  |  Link
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At max settings, up to fourteen fields for each output frame.

Don't compare QTGMC (its workflow) with that of other deinterlacers. it works different, it IS different.

Usual deinterlacers go "to weave, or not to weave, that's the question".

QTGMC basically is a motioncompensated temporal superresolution filter.
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Old 15th December 2011, 00:17   #1019  |  Link
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tormento sorry you don't seem to understand how this whole deinterlace thingy of interlaced video works.
If you deinterlace an interlaced video using QTGMC("slower") naturally both fields will be taken into account for deinterlacing and that is why the output has double the frame rate of the input.
It converts 50 fields per second (wrapped in 25 interlaced frames per second) to 50 frames per second. If you then try to end up with 25 progressive frames per second you are throwing away what originally was in every other field. So to take "both fields into account" you have to stick with double rate output, as simple as that. You cannot keep the motion of 50p or 25i (50i) with just 25p. The speed of the video stays the same of course, speed is not even involved at all.

Last edited by TheSkiller; 15th December 2011 at 00:23.
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Old 15th December 2011, 01:32   #1020  |  Link
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Quote:
Originally Posted by Didée View Post
QTGMC basically is a motioncompensated temporal superresolution filter.


I love how you get to the heart of the issue without dumbing it down much. Thanks Didée.

I have noticed that QTGMC does take both fields into account even if you output 25p, by this I mean there are more details on the output frame than exist on one field. I will have to leave how this is accomplished to others.
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