Old 10-31-2020, 04:58 AM   #1
Allybye
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Default Sever mangling! [partially solved]

Having now got video in Reaper working and looking through it there are sections in this old recording that are seriously suffering from interference.

It looks like the original playback machine had heads not locked onto the frame syncs during transfer to DVD so there is travelling noise bands.

Does anybody know if there are other resources out there that will help improve the video image/ Preferably low cost or free and standalone.

Example of frame with severe interference attached.
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Last edited by Allybye; 12-03-2020 at 03:52 PM.
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Old 11-02-2020, 02:45 PM   #2
Meo-Ada Mespotine
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Nope. To get rid of them, you can only either throw some kind of neural network onto it(complex, difficult and you probably don't have enough material to train that network to fill in the details) or to get rid of them by hand, frame by frame.
That kind of restoration cannot be done automatically via a tool. It's a very long and tedious process, where the missing details are "drawn or cloned in by hand) and therefore usually very expensive.
Some restoration projects can go to years of hard work by restorators for maybe 10 to 20 minutes of restored material, sometimes with better chances than what I see in the screen-capture.

You need to keep in mind, the distortion-lines are lost forever. You need to recreate what was there before. It's like recording a Led Zeppelin album via Telephone. The frequencies that cannot be transmitted through the telephone are lost so you would need to recreate them or get the original and make a better transfer of it in a studio and not via telephone.

Having said that: if you want to have a cheap solution: get the original source and make a better transfer, or if you have two transfers, try to intersect it with the second which hopefully has the distortions in other portions of the material.

If that's not possible you're probably out of luck....
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Old 11-03-2020, 02:54 AM   #3
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Thanks for your post.

You are right that it is not an easy task to make it virtually invisible. I do not have access to the original find of videotape copy and there is far to much to be done frame by frame by me!


I would have hoped there was some software to improve it. It would seem fairly simple for some of it as a lot of the more noticeable bits are significantly higher luminance amplitude and could be tamed (by compression) or substituted with nearby pixels. No doubt a slow process but I have yet to find any software to do that!

It used to be common in the old analogue days to use a dropout compensator to do line replacement and the like. Not perfect by any means but made things less 'in your face'.

I take my hat off to those who have the patience doing restoration work on all sorts!!
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Old 11-03-2020, 08:12 AM   #4
Meo-Ada Mespotine
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Code:
for some of it as a lot of the more noticeable bits are significantly higher luminance amplitude
This could theoretically possible via the video-processor. I'm not capable enough to code something like that but if you can somehow find these image-lines with higher luminance via code, you could alter them via the evalrect-function I think.
So in this case, some salvaging would be actually possible but it's a heck lot of trial and error-coding and probably still needs alterations, especially if the luminance-changes are "jumpy" between frames.
You can have multiple parameters in the videoprocessor, so a threshold and intensity envelope could be made into which you could influence the intensity of it.

But again, a heck lot of trial and error and probably also time-consuming.

Dunno about tools who could allow that. Maybe post-production-tools like AfterEffects or something, where you could add a mask to influence only the overluminanced parts?
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Old 11-04-2020, 02:30 PM   #5
Allybye
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Thanks again.
I think that would be beyond me too at this stage as I know nothing about the vid proc or the functions or even the language used!

Will carry on searching on the net for now!
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Old 12-03-2020, 03:50 PM   #6
Allybye
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Eventually tried Lightworks.
It has a few built in FX.
I managed to improve the "dropout" like interference a little...but far from eliminating it!!

I copied the video track to another and delayed it by one, two or three frames.

Stripping out the first frame in the original track using a luminance key from track 1 used the video of track 2.

This worked when the dropout banding was moving with a big frame to frame difference in position. Conversely "static" or slow movement fails to improve the picture.

Up to three frames delay has been used to good effect but obviously gets nasty with lots of movement. At one frame delay the movement problem still exists but is less annoying than the interference.
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