Video Darkened By QTGMC

[Danette]

I have never had such a problem when editing non-anime video but, with this DVD cartoon series, whenever I apply QTGMC, the video turns out very dark. I rip with MakeMKV, demux and then apply QTGMC(InputType=1) when encoding to x264 using MeGUI.

[poisondeathray]

What do you mean very dark ? eitherway - unlikely to be QTGMC

playback settings problem ? Gpu driver ? full/limited range ?

encoding settings problem ?

source filter problem ?

Did you preview the script before encoding ? in MPCHC or Vdub2 ? If you don't apply QTGMC (comment it out) is it still "very dark"? If not, it's not QTGMC, it's something else

[Danette]

What do you mean very dark ? eitherway - unlikely to be QTGMC

playback settings problem ? Gpu driver ? full/limited range ?

encoding settings problem ?

source filter problem ?

Did you preview the script before encoding ? in MPCHC or Vdub2 ? If you don't apply QTGMC (comment it out) is it still "very dark"? If not, it's not QTGMC, it's something else

Thanks for the response. Answering your questions:

What do you mean very dark ?

You can see the difference between the source and the darkened file here:
Source: http://www.mediafire.com/file/6gy41q3ym1ja0x1/Sample_5_-_Source.m2v/file
Darkened by QTGMC: http://www.mediafire.com/file/0ioccjk3ptmlxkj/Sample_5_-_QTGMC.mkv/file

playback settings problem ? Gpu driver ? full/limited range ?

No. It plays darkened on several different computers as well as a file played through the TV.

encoding settings problem ?

I don’t think so. I've used the same x264 settings on all other video with no problem. I’ve also tried other filters, such as TFM() and smdegrain() and the video turns out normally (same as source).

source filter problem ?

If you mean: “is QTGMC working correctly?” then no, because I can run other video through with QTGMC and it works fine.

Did you preview the script before encoding ?

I hadn’t tried that, but just did so with AvsPmod. It does not have the darkened image when viewed this way.

If you don't apply QTGMC (comment it out) is it still "very dark"? If not, it's not QTGMC, it's something else

When QTGMC is not used, then the video is not darkened, as mentioned in reference to TFM() and smdegrain() use. I think you meant the reverse of “If not, it's not QTGMC, it's something else” …right?

[Cary Knoop]

First of all, that source does not need QTGMC but IVTC.

Can you show your script?

[Danette]

First of all, that source does not need QTGMC but IVTC.

Can you show your script?

Yes, I know about the IVTC. In fact, I want to precede QTGMC with TFM. I use QTGMC to clean and improve because the resulting x264 file is half the size than when I don't use QTGMC. The problem started here: https://forum.doom9.org/showthread.php?p=1876497#post1876497

The script used for just QTGMC (to try to get at the darkening issue) is QTGMC().

The intended final script is:
TFM(slow=2)
QTGMC(InputType=1)

[Cary Knoop]

Yes, I know about the IVTC. In fact, I want to precede QTGMC with TFM.
That does not make any sense, TFM expects an interlaced format.

[ChaosKing]

Check also if you're using the latest version https://pastebin.com/raw/JLGwn7mE

[lvqcl]

the resulting x264 file is half the size than when I don't use QTGMC.

Probably it's half the size just because the video is dark.

[Danette]

That does not make any sense, TFM expects an interlaced format.

From the description: "TFM is a field matching filter that recovers the original progressive frames from a telecined stream."

Check also if you're using the latest version https://pastebin.com/raw/JLGwn7mE

I'm not. I'll give that a try.

Probably it's half the size just because the video is dark.

I thought about that, but have no way to test it without removing the darkening effect. Catch 22.

[Cary Knoop]

From the description: "TFM is a field matching filter that recovers the original progressive frames from a telecined stream."

Right, so do not plug a telecined stream into QTGMC.

[Danette]

Right, so do not plug a telecined stream into QTGMC.

Oh, now I understand what you were trying to say. I find that, in progessive mode, QTGMC handles non-interlaced video as well as if it were interlaced.

[hello_hello]

The intended final script is:

TFM(slow=2)
QTGMC(InputType=1)

It's telecined, so this would give you 23.976fps and probably be better. Or is that what you meant?

TFM(slow=2).TDecimate(mode=1)
QTGMC(InputType=1)

I can't explain the QTGMC problem.

[Cary Knoop]

Oh, now I understand what you were trying to say. I find that, in progessive mode, QTGMC handles non-interlaced video as well as if it were interlaced.
But there are no residual interlacing artifacts in the source, are you using QTGMC as an alternative form of noise reduction?

It's a very simple source, have you tried blurring everything but the edges?

[Danette]

It's telecined, so this would give you 23.976fps and probably be better. Or is that what you meant?

TFM(slow=2).TDecimate(mode=1)
QTGMC(InputType=1)

I can't explain the QTGMC problem.

I was mainly speaking to the InputType=1 for handling progressive mode, but I'm not so concerned about it being 23.976fps at this point (I'll probably end up doing that, though). My main concern is eliminating that darkening effect.

But there are no residual interlacing artifacts in the source, are you using QTGMC as an alternative form of noise reduction?

It's a very simple source, have you tried blurring everything but the edges?

Yes, I use QTGMC mainly for general cleanup, sharpening, shimmering removal and whatever else it does (when not concerned about deinterlacing) in a simple package as opposed tweaking multiple filters. Not sure why or how to go about blurring the edges.

Check also if you're using the latest version https://pastebin.com/raw/JLGwn7mE

Was able to try it, but received the error message: "I don't know what 'AvsPlusVersionNumber' means" and I have SMDegrain 3.1.2d installed. Any idea how to get around that?

I'm curious: have any posters tried running the "Sample 5 - Source.m2v" file through their own QTGMC encoder to see if they get the same darkened result?

[ChaosKing]

Newest smdegrain v3.1.2.102s https://github.com/avisynth-repository/SMDegrain

[Cary Knoop]

I truly don't get why you need QTGMC after you perform a IVTC, just use a good denoiser.

For instance here is the clip after an IVTC and some denoising:
https://www.dropbox.com/s/y0h6lv9cpvhybhu/stones.mov?dl=0

[Groucho2004]

I truly don't get why you need QTGMC after you perform a IVTC, just use a good denoiser.He explained it:
Yes, I use QTGMC mainly for general cleanup, sharpening, shimmering removal and whatever else it does (when not concerned about deinterlacing) in a simple package as opposed tweaking multiple filters.
Nothing wrong with that. I just tried it on his clip and the noise stabilization works quite nicely.

[Cary Knoop]

Well, here is the comparison with QTGMC, it's less effective.
https://www.dropbox.com/s/4th1far87pjm75b/stones2.mov?dl=0

And he may explain it but that does not mean I agree with it.
I think QTGMC is quite good at deinterlacing but it does not solve everything but the kitchen sink.

[Danette]

***SOLVED***

Newest smdegrain v3.1.2.102s https://github.com/avisynth-repository/SMDegrain

The updated QTGMC did the trick. Interestingly, AnimeIVTC did not work on these files either and now it does. I suspect that it was the SMDegrain 3.1.102s update that was at the crux of the solution.

Probably it's half the size just because the video is dark.

Unfortunately, both our suspicions were right: the darkened file was much smaller because of the darkening. So, I'm back to a file that, after an x264 encode at crf 18, the file is about equal in size to the source.

just use a good denoiser.

In the interest of trying this to see if it has any effect upon the size, what denoiser do you suggest, along with your suggested settings?


Thanks to all who participated in this challenge.

[Cary Knoop]

If it is size what you are worried about denoise it to the max and use hevc. Here is a sample using CRF=18 at 3.47MB:
https://www.dropbox.com/s/nkwdzkybeuo783g/stones.hevc?dl=0

I would use BM3D in combination with KNLMeans.

The other things you might want to do is:
- stabilize the frames
- get rid of the mosquito noise.

[Groucho2004]

Well, here is the comparison with QTGMC, it's less effective.Less effective, yes. But some prefer a less drastic approach. Different strokes...
And he may explain it but that does not mean I agree with it.That's fine, you don't have to. :D

[Danette]

Less effective, yes. But some prefer a less drastic approach. Different strokes...

That, pretty much, sums it up. I took a look at both my file and the multi-filter-modified file on a big screen and, to my eyes, could not see an improvement with the more effective approach. In fact, it looked a little like it had lost some detail.