Quantcast Flickering colours on VHS tape? - Page 11 - digitalFAQ Forum
  #201  
01-10-2017, 01:00 PM
sanlyn sanlyn is offline
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You're going to have to fill in some blanks here. How does Firefox figure in this workflow? What are you exporting with AE (I assume you mean some edited/joined segments)?
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  #202  
01-10-2017, 01:26 PM
koberulz koberulz is offline
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Menu animations for an unrelated DVD.

Previously, if I was running an encode I wouldn't be able to browse the web while it was going; I'd have to pause it if I needed to do anything. That is no longer the case.

Same with MeGUI running a Blu-Ray encode at the moment, and not really impacting the performance of Firefox. The browser is irrelevant to the encoding process, it just seemed like maybe more of the processor was focused on the encoding previously? Or maybe this is a positive, and it's evidence my new one is capable of more. It's not really my area. First pass is estimated at a couple of hours, and used to be four or five at a minimum, so there's that.
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  #203  
01-10-2017, 01:29 PM
sanlyn sanlyn is offline
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What does all of this have to do with how you're matching shots? If you're running other apps and encodes and browsing the net, you can't complain about how fast or slow your basketball project is running.
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  #204  
01-10-2017, 01:37 PM
koberulz koberulz is offline
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Quote:
Originally Posted by sanlyn View Post
What does all of this have to do with how you're matching shots?
Nothing whatsoever, they're two unrelated subjects. The speed of my machine in general is relevant to actually running those MCTD scripts, and the hardware replacement is the reason I had to put this on hold, so it ties back into the broader picture of the project as a whole but doesn't relate to the color work specifically.

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If you're running other apps and encodes and browsing the net, you can't complain about how fast or slow your basketball project is running.
Right now, I have other more urgent things that have stacked up while my computer has been dead - mostly getting current-season games from my near-full PVR to Blu-Ray discs - and I need to go back over things as it's been so long I've forgotten large parts of what I'm doing. I ran the test file straight off the bat just because I was really curious as to how it would compare; I've since been doing other things while trying to get an idea of how much of a speed/performance difference there is.
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  #205  
01-10-2017, 01:50 PM
sanlyn sanlyn is offline
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You're certainly busy. I run one project at a time, if no other reason than to take a break from the tough work on the bad capture I mentioned. I'll be getting back to that one for a few hours today. But it looks as if speed and other matters have improved in all respects. It's not uncommon for that project t be interrupted for days or weeks to attend to other matters, like all of the old TV shows I'm recording and editing on a DVD recorder to watch on weekends. (Why do they have to show all the good old stuff in the middle of the night???). I just finished re-syncing an HD capture from TCM, as that HD PVR does odd things to audio when the transmission is noisy. Takes about a boring hour to demux, remux, edit a movie and transfer it to a hard drive for playing on the OPPO later.

Yes, indeed. There's plenty going on. I like to do work on one thing at a time and take breaks when I get tired. Color work is time consuming in itself. I fix color, then let it rest a day or two and come back, and it will not look the way I thought, so I'm at it again. It's a matter of prioritizing and not wearing myself out.

Speaking of priorities, I'm over two hours late for lunch.
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  #206  
01-11-2017, 12:02 AM
sanlyn sanlyn is offline
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Quote:
Originally Posted by koberulz View Post
I don't mean using Premiere for all of it, I just mean for the final color correction.
If you work in RGB, any clipping in YUV will be permanent; there is no way to retrieve data after it's clipped. You'll have to work in YUV with Premiere and you'll have to use PP's saturation controls to target specific color ranges, if that's possible in YUV -- which I don't think is available with PP unless you're in RGB. If you find a way to stop the chroma flicker in Premiere, go right ahead. I don't see that it's possible to target that kind of glitch with PP or any other NLE. But mnif you want to try and invent a new wheel, it's up to you.
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  #207  
01-12-2017, 10:51 AM
koberulz koberulz is offline
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Hardly a new wheel, lordsmurf has mentioned doing things that way a few times.

Obviously I'd need to do some work in AviSynth first, to make everything RGB-safe and whatever else Premiere can't do, but I get the impression from what lordsmurf has said in other threads that Premiere and After Effects might be the way to go for matching the colors of the different angles, etc. But I'm not sure exactly how I'd need to break it up, in terms of what needs to be done in AviSynth before it's ready for Adobe.

But regarding RGB conversion, is it necessary to add that to the end of an AviSynth script? VDub will do that conversion on its own if it needs to, and if it doesn't surely it's better to stay in YUV all the way to DVD?
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  #208  
01-12-2017, 11:26 AM
sanlyn sanlyn is offline
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The reason it's done in Avisynth is because Avisynth affords the means to do so with greater precision. If you're working in YV12 in Avisynth and you open that file as YV12 into Premiere and allow Premiere to make the conversion to RGB and back to YV12 fo encoding you're asking for trouble. Conversion between colorspaces is subject to numeric rounding and chroma placement errors, and errors based on frame structure, which Avisynth holds to a minimum. NLE's aren't as adept at that sort of thing and to a lesser neither is Virtualdub. You probably won't see a difference.

If you want to try Premiere for the color work It's up to you. Premiere isn't likely to resolve the flicker problem. If you found a way of matching colors between two videos using Adobe apps, that's OK. I have no problems doing it in Avisynth and VirtualDub and do it all the time.
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  #209  
01-13-2017, 05:40 AM
koberulz koberulz is offline
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The other thing, just having a play around with it now, is that it's kind of hard to tell what color things actually are due to all the chroma noise. So should I be doing any color correction at all in the first step?
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  #210  
01-13-2017, 09:24 PM
sanlyn sanlyn is offline
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The flickering filters, YUV levels and de-spot processing take enough time as it is. I did additional color tweaks in Virtualkdub, which is where the RGB conversion came in. In Virtualdub's output I saved the RGB color work as YV12 because the next step was joining segments and encoding.
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  #211  
01-13-2017, 11:08 PM
koberulz koberulz is offline
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Quote:
Originally Posted by sanlyn View Post
The flickering filters, YUV levels and de-spot processing take enough time as it is.
Compared to what? Not sure what this is a response to.
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  #212  
01-14-2017, 07:09 AM
sanlyn sanlyn is offline
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I think you forgot your own question. Go back to the question you asked in post #209. Fixing the chroma flicker is part of color correction, and no you don't have to do 100% of the color correction at the same time. I did part of that in VirtualDub after running the Avisynth filters. Remember that you do have some moments of illegal luma and chroma levels brighter than y=235 that have to be fixed before you convert to RGB for color work, whether you work with RGB color in Virtualdub or in Premiere, as mentioned in previous posts.
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  #213  
01-14-2017, 07:54 AM
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Quote:
Originally Posted by sanlyn View Post
Fixing the chroma flicker is part of color correction, and no you don't have to do 100% of the color correction at the same time.
I need to review this whole thread, but wanted to comment on this one tidbit.

Chroma NR/correction affects color. And color correction can affect chroma noise. It can lead to catch-22 situations, and is one reason (of many) that I always remind people that restoration is about making things better, not perfect. Yes, as perfect as possible. Keyphrase = "as possible".

Just to flesh out sanlyn's statement.

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  #214  
01-14-2017, 09:44 AM
koberulz koberulz is offline
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Quote:
Originally Posted by sanlyn View Post
I think you forgot your own question. Go back to the question you asked in post #209.
You said that a certain process took enough time 'as it is', implying a comparison with a different process. I'm not sure what that alternate process is that you had in mind.

Quote:
Fixing the chroma flicker is part of color correction
Okay, basically, I went to work with a frame and it seemed really red. And I went to the next frame and it seemed really green. Just because of the noise, it varies wildly from one frame to the next which makes it impossible to know what adjustments should be made. So is it better to attack the noise first in that instance, and everything else later?

Quote:
Remember that you do have some moments of illegal luma and chroma levels brighter than y=235 that have to be fixed before you convert to RGB for color work
Yeah, I'm across that. What I'm wondering is whether I bother to do anything other than making them legal in AviSynth, then use VDub/Adobe for the rest.



Quote:
Originally Posted by lordsmurf View Post
I need to review this whole thread, but wanted to comment on this one tidbit.
Can you elaborate on the process of using After Effects and Premiere for color work?

And while I've got you, what do I need in order to run that super-awesome top-secret script of yours? This new CPU isn't behaving with Windows 7 at all, and the i7-6700K is looking awful tempting.
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  #215  
01-14-2017, 11:39 AM
sanlyn sanlyn is offline
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Quote:
Originally Posted by koberulz View Post
You said that a certain process took enough time 'as it is', implying a comparison with a different process. I'm not sure what that alternate process is that you had in mind.
The initial processing stage included smoothing chroma flicker and luma flicker, cleaning spots and dropouts, cleaning up edges (halos, chroma bleed), and adjusting overall levels where required, not to forget cleaning up tape noise. Those are slow running processes. What remained after that is overall color balance and gamma tweaking, which I did in VirtualDub where it was needed.

Quote:
Originally Posted by koberulz View Post
So is it better to attack the noise first in that instance, and everything else later?
It's better to attack boise first and it's better to do that in YUV before moving into RGB for other filters. You wouldn't want to shuttle back and forth between colorspaces. Work in YUV, then work in RGB. YUV->RGB->YUV->RGB accumulates numeric rounding and sampling errors.

Quote:
Originally Posted by koberulz View Post
What I'm wondering is whether I bother to do anything other than making them legal in AviSynth, then use VDub/Adobe for the rest.
Illegal levels should be adjusted in YUV first. The subject of how bad levels results in clipped brights and/or crushed darks when converted to RGB has already been covered. Once these problems occur in RGB, you can't retrieve those details.
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