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So, on this batch of DVD-R's I'm cleaning up, the levels are just...way too dark. Like, max IRE of 200 type dark on first, maybe second, gen NTSC tapes. A simple levels readjustment just looks overblown, and a brightness adjustment looks crummy. I know you can't reclaim what's already been thrown out by a bad VCR and DVD-recorder, but there's gotta be a way to make it, well, watchable.
On a different note, on some disks, there's a strange, almost tearing/slurping sound in the upper-midrange. I really don't know how to describe it. It's almost like bad noise-reduction or a really compressed MP3 file. It seems to come and go on different recordings. The source is pretty junky, being fairly well-loved SLP mono VHS tapes recorded in 1992 (8/5/92 to be exact: the transferring VCR, and presumably the recording VCR, shows the date of the recording-this was a Panny feature, right?). Taking off anything above 4k seems to reduce it, but it takes off a bit too much audio for my taste. Is this the tape, the deck, the DVD machine, or just my speakers?
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RE: dark levels
You need to work in YUV, and lift the Y values up or offset, and then perferentially boost shadows
If you work in RGB, you will clip values Y <16 . You have to be careful about what software you are using
The problem with making it "brighter" or boosting shadows, is it will reveal a lot of crap and compression noise - I'll leave that up to you to decide what to do with it
This was done in avisynth . You still need to make some adjustments to color and noise but it will get you started
(is that an upskirt shotCode:levels(0,1,255,16,255,false) hdragc(max_gain=2, coef_sat=0.80)
from the 80's ? )
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For the audio tearing / slurping, can you point out the time at which it occurs in that clip ? You said it comes and goes
I hear some clicking and other artifacts that might be what you are referring to, but just want to be sure -
It would appear to be. Too damned dark for me to tell :POriginally Posted by poisondeathray
RE: dark levels
(is that an upskirt shot from the 80's ? )
And yeah, boosting up the levels you can just see the noise (Beta is better my *ss!). I usually do my color work AFTER cleaning out the noise, so it shouldn't be that much of a problem.
It comes and goes throughout that one episode (the rest are just plain ol' muddy), and especially in the intro. It's most prominent when you listen to the vocals, especially around 's' sounds (but it's not the staticy burst you get with regular essing). Maybe there's some industry standard term for all this that I don't know, but I call it slurping/tearing because that's what it sounds like. Maybe icy or hard is a better way to describe it? I've got another tape that has the same sorta problem, if it helps illustrate it any better.Originally Posted by poisondeathray
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Pretty bad source, almost fubar if you want my opinion.
Brightening the shadows and blacks will just open Pandora's jar. -
Do you still have the original tape? This looks like it might have resulted from a bad analog signal chain. You might get better results using a different VCR, cables, capture card, or capture settings.
As for adjustment, like all dark videos, adjusting using "brightness" or "contrast" will create a mess. You need to adjust each part of the histogram separately. I use Sony Vegas, and it has a "Color Curves" adjustment that lets you create a histogram curve which gains or suppresses each brightness level in the original by a different amount. Thus, you can hold the blackest part of the image at the same level, so that you get good looking contrast, but then gain those pixels that are dark, but not completely black, but a substantial amount. Doing this should let you get something that looks like the really good result posted in #2 above. You will then need to apply some sort of denoiser (I usually use MDegrain2) because the resulting video will contain a lot of noise. -
^Yes, curves are great and allow you to make non linear changes. Vegas gets around the clipping problem by doing a studio RGB conversion, which is very similar to a full range conversion. Moreover, doing it in a NLE or dedicated program allows you to more easily make adjustments per scene by adjusting/keyframing values over time.
If you don't have a NLE, a free way to use curves would be gradation curves in vdub, or gimpcurves in avisynth with gicocu, but you would have to convert to RGB using a full range matrix first (eg. in avisynth), or you'll run into the same clipping problem . (Newer versions of vdub have control over matrices for yuv<=>rgb conversions in the color depth settings, but they don't work properly yet), and still more difficult to make adjustments over time
There is a free version of davinci resolve available as well. It's the "gold standard" for color correction. The free version is limited to 2 nodes, but still very powerful -
I've got Premiere CC and Vdub, so I'm no stranger to NLE's. The curves work pretty well, except I'm having a bit of a hard time trying to find a sweet-spot between proper levels and not blowing the hell out of everything else :{
Neither of these tapes are in my possession. The Spacecats thing comes from a bootleg DVD I'm cleaning for a friend of mine who collects that rare stuff, and the MTV comes from a Betamax tape that my cousin transferred over the summer (the original tape is currently in Oyster Bay, NY, quite a ways away). I was there to help him with the transfer, and it didn't look that bad on the TV (the chain was just a Sony Super-Beta deck plugged into a Toshiba DVD-Recorder, pretty similar to my own setup really-no maladjusted Proc Amps or TBC's). How it went from decent to murky just confuzzles me. His TV must have been really screwy!Originally Posted by johnmeyer
Last edited by John97; 18th Nov 2014 at 11:13.
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Crap, that spacecats is a catchy jingle. Can't get it out of my head now
I downloaded a youtube version to see what sorts of sounds were supposed to be there, and it has similar artifacts. Might have even been the same guy uploading it
You probably already know this but be careful about using "RGB curves" in premiere, because you will clip the shadows as well, before even using it. You need to use a YUV filter to bring the range to "normal" before using any RGB filters -
The '80s/'90s had a knack for catchy themes for terrible shows, that's for sure! :P As far as cartoons go, it's like as if that guy we all know who cracks jokes about everything and anything made his own show with no editing beforehand >_>
If we're looking at the same YT version, it does sound the same. Heck, the VCR time thingy looks the exact same. Only thing missing is the TOTALLY RAD TO THE MAX presenter thing at the beginning. He's probably the guy who made the DVD-R.
https://www.youtube.com/watch?v=BvPHsYlj6MI
What's a good YUV filter, for Premiere or Virtualdub?Last edited by John97; 18th Nov 2014 at 19:54.
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Premiere supports YUV, if you look at video effects there is a column to mark if an effect supports YUV.Originally Posted by John97
But there is really not much you can do with this source. Also the published MPEG-2 versions (VH1 collection and Absolutely ABC) are rather dark as well.
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Yes I think that was the same one, it was the 1st hit on google. There aren't too many versions floating around on YT
What's a good YUV filter, for Premiere or Virtualdub?
Basically anything that's labelled "YUV" in premiere. Like fast color corrector . "RGB Curves" is obviously "RGB"
The concept here is YUV to RGB conversions . IF you try to adjust the screenshot in your 1st post, it will be "impossible" to improve much, because the shadow detail has already been clipped (loss of data) from the YUV to RGB conversion for the screenshot . The screenshot is in RGB, our displays/monitors work in RGB
The original MPEG, in YUV contains all the data that was originally recorded. What happens with a standard Rec601 conversion to RGB, is Y' 16-235 gets "mapped" to RGB 0,0,0 -255,255,255. Notice 0-15 , and 235-255 get cut off. Well that 0-15 happens to contain usable details in your mpg . You can illustrate this by looking at a Y waveform, or YC waveform in premiere . That area in bright yellow in the brown zone is 0-15 getting clipped. All values in that brown zone will get clipped (on both ends). Vegas gets around that by using "studio RGB". Essentially Y' 0-255 gets "mapped" to 0,0,0-255,255,255 , so that head and tail room are preserved, not clipped.
The avisnyth code might be hard to understand, but it's analogous to levels in photoshop, or after effects, or premiere
That 0,1,255,16,255 => that "16" is the output black level, so that would bring that clipped zone back up to "zero" or legal range. Then you can do whatever you want in RGB . If you look at say fast color corrector in premiere, you'll notice those numbers as well . So if you adjust output black by 16 with fast color corrector, you'll get the same effect in YUV
So all you are doing is bringing that "illegal range" data, back in to "legal range" . You're shifting the values up. Here is the levels adjustment alone
After that, you want to use some non linear changes like curves to preferentially give the shadows some better contrast. You want to spread out the value and boost it a bit. Another way you can do this in Adobe products is the "Shadow/ highlight" filter . Or in curves, if you have difficulty with higher values and blowing out, just set a knot in the mid to upper range to lock those values down -
No good, because it does not work in YUV.Originally Posted by poisondeathray
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Originally Posted by newpball
No good, because it does not work in YUV.Originally Posted by poisondeathray
You use it after adjusting and legalizing values in YUV first. That was the purpose of the last few posts. Maybe you should read it again
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So I tried it out in Vdub, and whaddya know there's something in the dark!
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You are not correct, that does not happen in Premiere Pro.Originally Posted by poisondeathray
Mapping 16-235 YUV onto 0-255 RGB is not the same as clipping values. In fact in 32 bit RGB there is no loss of information when you map 16-235, but there is loss in 8 and 16 bit. The loss is not due to clipping but due of rounding since obviously 16-235 does not expand to 0-255 with only integer values.
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Originally Posted by newpball
You are not correct, that does not happen in Premiere Pro.Originally Posted by poisondeathray
Mapping 16-235 YUV onto 0-255 RGB is not the same as clipping values. In fact in 32 bit RGB there is no loss of information when you map 16-235, but there is loss in 8 and 16 bit. The loss is not due to clipping but due of rounding since obviously 16-235 does not expand to 0-255 with only integer values.
By DEFINTION, an ITU Rec 601 or 709 conversion clips values
Mapping 16-235 to RGB 0-255 means you clip values . If I were to map 0-255 to 0-255, there would be 1:1 mapping and no clipping
There is loss in all 8,16, and 32 bit modes. ALWAYS. Why ? Because YUV <=> RGB transforms are lossy by definition. YUV is a larger colorspace model than RGB, and can hold more values than can be expressed by RGB color model. There are out of range and out of gamut colors that cannot be expressed in RGB . All RGB values can be expressed in YUV, but the reverse is NOT true. You can minimize the rounding losses when working at higher bit depths , but you still incur losses that are out of gamut.
However, you are partially correct - In 32bit mode in premiere and AE is a special mode that does not clip right away , because it actually acceses YUV values before the RGB conversion . But strictly speaking, this is NOT an ITU Rec 601 /709 conversion in this mode . However - not all filters in PP/AE work in 32bit ! If you legalize in YUV first, you will never go wrong, in any mode.
RE: vdub
Yes you can do it in vdub, because the "levels" filter can work in YUV. If you checkmark "show pixel formats" in the filter menu, it will show what filters are working in which color space.Last edited by poisondeathray; 18th Nov 2014 at 20:22.
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Point is that what you wrote is not correct for Premiere Pro (and other NLE's as well).
If you stick to YUV and 32 bit filters you won't clip values. And no, RGB curves does not clip values it works just fine in Premiere Pro. However the shadow/highlight filter you mention DOES clip. -
Originally Posted by newpball
If you legalized values as suggested, you won't clip with any mode, any bit depth, or any filter (including shadow/highlight), in any software
You are right about CC, but RGB curves does clip in earlier versions of PP (CS4 and below didn't have a YUV timeline, although they had YUV unlabelled filters), and other NLE's that use ITU Rec conversions. What I said about vegas is correct
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