Quantcast Flickering colours on VHS tape? - Page 10 - digitalFAQ Forum
  #181  
11-21-2016, 02:47 PM
sanlyn sanlyn is offline
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ChromaWarpSharpener is a more complicated way of sharpening chroma and tightening color around edges. I threw it in to see how long it would take for VDub to get tired and run out of memory reloading scripts again and again.

My stupid typo "The Scriot ! and Script 2 images have cleaner whites and blacks" should read "The Script1 and Script 2 images have cleaner whites and blacks". Apparently the first two coffees at that hour in the A.M. are not enough.

You can use as many "#" marks as you want, but there must be at least one to make a comment of the text following it.

Last edited by sanlyn; 11-21-2016 at 02:58 PM.
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  #182  
11-21-2016, 10:38 PM
koberulz koberulz is offline
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Quote:
Originally Posted by sanlyn View Post
My stupid typo "The Scriot ! and Script 2 images have cleaner whites and blacks" should read "The Script1 and Script 2 images have cleaner whites and blacks".
Right, I figured that. I was asking what caused the difference in the whites/blacks.

I still don't understand your suggestion about three copies of the unprocessed avi, etc.
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  #183  
11-22-2016, 03:01 AM
sanlyn sanlyn is offline
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I'm not certain about the white/black tint cause, but it can be more easily corrected in Virtualdub. I believe moving some hues toward another hue location might have fixed one problem (I think you referred to a magenta tint) but caused another. Moving magenta toward another hue location would reduce magenta everywhere, which would cause its opposite color (green) to appear more prominent in other areas. Getting a clean white balance in YUV is a chore.

Three copies of something, six copies, whatever, I'm not sure what you're doing to match up camera shots. Go with what works for you.
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  #184  
11-22-2016, 06:58 AM
koberulz koberulz is offline
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I don't understand what your suggestion was, though. And I mean, if it's causing color issues, it's obviously going to defeat the purpose...
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  #185  
11-22-2016, 07:17 AM
sanlyn sanlyn is offline
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I'll reply soon with an example of what I'm working on now. Stay tuned.

[EDIT]
My current pproject is an old family tape photo'd by my sister in 1992. There was a luncheon in her house with 40 people attending. She is walking around the interior and out into the rear patio, continuously shooting. She had a cheap camera with autogain
turned on, so The light levels change drastically when a lamp or bright window enters the frame. Add to this, some shots were made in what you'd call "available darkness."

Correcting gamma and contrast for underexposed segments reveals horrible low-level noise from the camera's sensor. Second, when the light levels return to near-normal it's a continuous, unbroken scene. It's not possible to make a single capture with levels set up to properly handle every segment, as the light changes are too drastic. So I made 3 captures, one at raised black levels for the darkest scenes, one at normal levels, and one at lowered black levels for overexposed shots. From those three I have to pull off the required segment, normalize it with filters, then join the segments with dissolves to compensate for the fast level changes. Sometijmes an autogain plugin like AutoLevels or HDRagc is used on a shot to help make it match the next segment. I determine the frame numbers involved by looking at two captures in two copies of VirtualDub. As each segment is completed, it's joined to the master project.

In your case you have one capture. Each camera shot has different problems. So I'm not sure how you're handling the problem of joining the scenes from three camera shots or determining what filters to apply to each segment. If you're not using filters to customize each set of camera shots, then I have no idea how you're compensating for different problems, or even if you're using different filters for each segment, or how you're dertermining frame numbers for those segments that require different treatment.

Examples of different exposure and filtering problems with that home video were posted a while back. The corrections themselves were rather crude and quick and have since been improved. But the post illustrates the problems I encountered and a couple of ways they were solved. These examples were both from the same capture.
Encoding from Huffyuv?

Last edited by sanlyn; 11-22-2016 at 08:06 AM.
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  #186  
11-22-2016, 08:43 AM
sanlyn sanlyn is offline
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Quote:
Originally Posted by koberulz View Post
I don't understand what your suggestion was, though. And I mean, if it's causing color issues, it's obviously going to defeat the purpose...
My suggestion was to avoid changing a hue to another hue. It affects the entire image wherever that color appears. Changing magenta in black and white areas will make blacks and whites tend toward green because part of the magenta spectrum that was in those colors has been changed.

The colors black and white and every shade of black and white in between (grays) consist of three RGB colors: Red, Green, Blue.
Black = Red 0, Green 0, Blue 0, or RGB 0 0 0.
y=16 "black" = RGB 16 16 16.
Very dark Gray = RGB 32 32 32.
Dark Gray = RGB 64 64 64.
Middle Gray = RGB 128 128 128.
Light Gray = RGB 192 192 192.
Video white = RGB 235 235 235.
Super white = RGB 255 255 255

If you change the hue of magenta in any of those shades of Black, Gray, or White, you reduce blue and red (magenta) components, making the hues look more green.

Magenta is called a secondary color because it's composed of two primary colors, Red and Blue. The "pure" 100% RGB values for primary and secondary colors are:

primary:
RED = RGB 255 0 0
GREEN = RGB 0 255 0
BLUE = RGB 0 0 255

secondary:
YELLOW = (Red + Green) = RGB 255 255 0
CYAN = (Green + Blue) = 0 255 255
MAGENTA = (Red + Blue) = RGB 255 0 255

That's known as the basic color wheel in all color correction for all graphics. The color wheel for printing uses a different system. If you can identify those pure hues or something close to them, you can identify a specific color cast imbalance if one exists.

Many color problems can't be fixed in YUV very well, others can't be fixed in RGB, which is why so many advanced NLE's allow sophisticated color, levels, and saturation corrections in both YUV and RGB. Note that changing the saturation of a color doesn't change its hue. Intense blue and less saturated blue are still blue. Changing saturation changes a color's contrast level, not its hue.

Last edited by sanlyn; 11-22-2016 at 09:08 AM.
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  #187  
11-22-2016, 08:50 AM
koberulz koberulz is offline
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I have three scripts, one for each camera angle. Each open in AvsPmod and VDub.

Each instance in VDub is set to a frame where the relevant camera is being used. I'm then fiddling with the color settings in each script until they all look roughly right, flicking between them to make sure they match (or at least go close).

I'll then output each script as an AVI, and use Premiere to cobble it all together. If I notice during this step that there are individual shots that need further, or different, work, I'll get to them then.

EDIT: You posted while I was posting; I meant the suggestion about the matching process. You said earlier the multiple instances of VDub might be causing the random color changes.
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  #188  
11-22-2016, 10:19 AM
sanlyn sanlyn is offline
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I can't answer completely for any effect AvsPmod might have on VirtualDub.

The differences between camera shots would each require a different script or different filter settings, true. In my case I would be cutting the process into segment sets for each camera, come up with a segment numbering system (Such as A01, A02, etc., B01, B02, etc., C01, C02, and so forth), then join them later. At least the same filters would be common to each set individually. Once you have settings for set "A", almost all of them would use the same settings for "A" segments. Same for set B, and so on. Running three scripts at the same time would drive me bananas. But you're free to arrange it any way you feel is best for you.

After the project is joined and encoded, you wouldn't have to save every work file. But I'd save the scripts and notes. I usually do that with a big Excel spreadsheet and have had to do it on several occasions. A few years ago I did a 3-hour opera tape that used 4 cameras and intermission and intro segments, with color problems on two cameras. It was damaged, discolored, telecined tape with problems worse than yours. I more or less cut my Avisynth teeth on that one, with lordsmurf and several others to drag me kicking and screaming all the way. So I've been there. Try a single 2-minute aria with 3 camera angles and over 200 bad frames. If you saw a starting sample of that one you'd cry. Altogether there were some 2500 bad frames in 3 hours.

Beautiful classic opera, by the way. Mignon, in French, and no reprints of the original tape anywhere. The tape was issued only to subscribers of the opera society in 1995 in France.
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  #189  
11-22-2016, 10:30 AM
koberulz koberulz is offline
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Quote:
Originally Posted by sanlyn View Post
Running three scripts at the same time would drive me bananas.
I've only got them open at the same time to adjust the colors so they're similar, and I can compare by alt+tabbing. Once I'm happy with the results, I'll pick a script, create the AVI from it, then do the same for the second script, then the third. Not even sure what you had in mind re: running three scripts at the same time?

Quote:
After the project is joined and encoded, you wouldn't have to save every work file. But I'd save the scripts and notes.
Was already my plan. I'll keep the capture, the restorations, and anything needed to get from one to the other(s). Plus I was thinking a deinterlaced MP4 of everything all put together, for easy creation of YouTube videos, etc.

What sorts of notes would you keep, and how does it become an Excel spreadsheet? I was thinking just a subfolder for each camera, with numbered scripts, would be enough.
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  #190  
11-22-2016, 10:37 AM
sanlyn sanlyn is offline
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I kept an Excel spreadsheet of segment numbers and how they were related. The spreadsheet is rows and rows of indented text notes and segment names, with script names, and spreadsheet pages for each Act of the 4-act live performance. And I recall keeping lists there of bad frames in many segments. Notes were there, and in small text files and in comment blocks in the scripts. I have them somewhere on s DVD data disk.
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  #191  
11-23-2016, 12:38 AM
koberulz koberulz is offline
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Rebooted and only ran the right-hand script, and it displays the same as yours regardless of how many times I press F2.
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  #192  
11-23-2016, 07:46 AM
sanlyn sanlyn is offline
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Rebooting and freeing up some memoery for the system and VirtualDub, as well as running one script at a time on the same master file, can work wonders. I reboot 3 or 4 times a day on all-day projects.
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  #193  
11-24-2016, 12:28 AM
koberulz koberulz is offline
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...and as soon as I opened up the other two and started working on them together - Notepad instead of AvsPmod - it all went haywire again.
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  #194  
11-29-2016, 01:31 AM
koberulz koberulz is offline
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Just tried to work with some HD video, which locked up my entire computer and I had to reboot.

It took 5:48 to get to the login screen, 2:25 of which was the black screen with the underscore, prior to the intel splash screen and the BIOS Settings/Boot Options prompts. I stopped timing at that point but it was another 15-20 minutes after logging in before I could actually open and use any programs.
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  #195  
11-29-2016, 04:11 AM
sanlyn sanlyn is offline
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So, when are you going to have someone check your system and components? The blinking cursor means BIOS startup is waiting for Windows to load an operating system from the hard drive. That's a hardware problem, likely a hard drive, hopefully not a motherboard controller chip. Or could be registry corruption. Or could be a rootkit infection taking its time to make a copy of your login screen and desktop so it can control your computer. Usually it's a hard drive going through its death throes ("thrashing", which you can sometimes hear as hard drive activity and a constant drive activity LED indicator. Do you ever look at those LED activity lights?).

You can cruise the 'net all week and find a ton of explanations, none of which will work until someone gets their hands on your PC. Because RAM has been discounted, I would suspect the hard drive first, system corruption second. A new hard drive and a software cloning package that runs from a bootable CD is the cure for a failing drive (or install Vista on a new drive). A Vista reinstall is the cure for the second case. If the guy(s) who looked at your system earlier found "nothing wrong", they're idiots. Find another tech who'll run some diagnostics instead of scratching his head and shrugging.
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  #196  
11-29-2016, 09:14 AM
koberulz koberulz is offline
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Quote:
Originally Posted by sanlyn View Post
A new hard drive and a software cloning package that runs from a bootable CD
Could you expand on this? CrystalDiskInfo does have C: listed as 'Caution'. I've backed up and replaced my data drives before, but never the drive with the OS on it.
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  #197  
11-29-2016, 02:55 PM
sanlyn sanlyn is offline
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Well, it depends on what you to do with that C: drive. If a drive test is giving warnings, you likely wouldn't want to reinstall the OS onto it. There is disk imaging software (a compressed, complete version of a drive with its boot partition intact, etc.), the one I use is Paragon Disk Manager from three or four years back. Other brands are available. A disk image is made to another drive or to a USB hard drive, then it's copied and uncompressed onto another drive. The problem with Vista might be its licensing and re-use terms (do you have a Vista disk, or did you get only what was installed on your PC)? New PC's come with a hidden partition that has a restoral version of the original install. That's why you have to have a tech advise -- no one can't tell without a look into the file system and the PC.
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  #198  
01-10-2017, 09:32 AM
koberulz koberulz is offline
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Got rid of my motherboard and CPU, replaced them with a Gigabyte GA-H170-Gaming 3 and an intel Core i5-7400. Also upgraded my heatsink.

That file that took 5:23 to run on my old machine now runs in around 2:50. Which is nice, but given you said you ran it in 2:20, I struggle to be too pleased with that.

More specifically about this project, how much effort should I really be putting in at this point, color-wise? There are obviously advantages to working with the original YUV, but things like Premiere would do a better job of fixing things up.
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  #199  
01-10-2017, 11:52 AM
sanlyn sanlyn is offline
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If you can find a way to reduce the chroma flareup in Premiere Pro, it's up to you. NLE's are far more limited when it comes to this kind of repair. PP can work in YUV, but NLE's are not designed as repair apps like Avisynth. They're editors.And you still have to contend with different shots and different nosie problems along the way. I don't see where PP would be better or faster. Color isn't the only problem.

You've cut that run time about in half, which is great progress. Times will depend on what else is running, how much memory backup you've accumulated, and other factors. One time it might be a little slower, next time it could be faster. The mobo and CPU I'm using are a newer generation than the socket models and mobo you were using. My i3750 was specifically recommended in its day as the fastest MPEG encoder and video processor of the time short of the highest-end model. Newer models are even faster, but who has $1000 for the best of the new Intel CPU's? I don't see that a few seconds difference in run time is such a setback.

To compare efforts, I just spent 3 days to clean up 21 seconds of movie clip from a bad 1991 VHS recording, a mere 515 frames in the first half that I had to copy twice with two VCR's just to get enough good frames for the full camera shot of 876 frames, not to mention grungy color, rainbows, and funcky borders to fix. Now and then you run into disasters and it just takes time, patience, and the right tools. An NLE isn't the right tool for problems like the one you're faced with or the one I decribed. And I'm sill working with mine as well.

It took a full day's work to concoct the following frame repair and replace script to fill one clip with frames from three different clips. Try to guess what you could do in Pemiere Pro with the attached 2 caps to get the almost-final version:

Code:
# ####################################################################
# BaseVid: Video whose frames will be either replaced or kept as-is.
#          Ultimately this will be the output file.     
#
# Source_B1B: A different capture of the IVTC'd BaseVid. The file
#             has similar frames to BaseVid, some frames are cleaner.
#
# Source_B1AQ: A "deinterlaced" version of an IVTC'd file, with
#              different image coming off each video head.
#
# Source_B1BQ: Similar to Source_B1AQ, but a different capture.
#
# All Input videos are YUY2
# ####################################################################

BaseClip=AviSource(vidpath+"B1A_Liv10B1_ivtc.avi")
Source_B1B=AviSource(vidpath+"B1B_Liv11_ivtc.avi")
Source_B1AQ=AviSource(vidpath+"B1A_Liv10B1_ivtc_WorkQ.avi")
Source_B1BQ=AviSource(vidpath+"B1B_Liv11_ivtc_WorkQ.avi")

BaseClip=BaseClip.RemapFrames(mappings="
0 2
1 3
2 5
3 8
4 9
5 12
6 12
7 15
8 16
9 19
10 21
12 24 
13 26
14 28
15 29
17 35
", SourceClip=Source_B1AQ)

BaseClip=BaseClip.RemapFrames(mappings="11 22
 16 32
 20 40
 21 41", SourceClip=Source_B1BQ)

BaseClip=BaseClip.RemapFrames(mappings="[22 31] [22 31]
 [44 84] [44 84]", SourceClip=Source_B1B)

### ----sync to the audio from clip B1B --- ###
vid=BaseClip
aud=WavSource(vidpath+"B1B_Liv11_ivtc.wav")
AudioDub(vid, aud)
AssumeFPS("ntsc_film",sync_audio=true)
return last
And you thought you have problems.

Lordsmurf can use this unfinished sample if he wants for his fix-up thread. I'm not 100% satisfied myself. Attached: 2 original lossless telecined captures as mp4 and the (un)finished "final" with frames formatted for a later DVD.


Attached Files
File Type: mp4 capture1_Living10_B1.mp4 (24.85 MB, 18 downloads)
File Type: mp4 capture2_Living11_B1A.mp4 (14.45 MB, 14 downloads)
File Type: mp4 B1A_Liv10B1_ivtc_map_MVa-Final.mp4 (24.55 MB, 18 downloads)
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  #200  
01-10-2017, 12:33 PM
koberulz koberulz is offline
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I don't mean using Premiere for all of it, I just mean for the final color correction. Obviously spot removal, noise removal, and whatever else is going on in the AVS script (it's been way too long since I've looked it over, really; I'm probably going to have to take some time just to re-learn things) would be handled in AviSynth. But I'm guessing at some point the colors would be handed off to Premiere. The question is really just about how much needs to be done in AviSynth before they're Premiere-ready. Or After Effects, or whatever.

As it stands, I was trying to get all three angles to match, and look right, in AviSynth. From browsing around here I get the impression there are better ways of going about things.

Regarding speed: I'm exporting from AE right now, and browsing with Firefox just fine. Previously Firefox was almost impossible to use while exporting. But the export doesn't seem very fast, so I'm not sure if there's some sort of tradeoff that was being made before that isn't being made now.
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