Well, VHS capturing Mostly cartoons, having some questions:)

[juhok]

Heh I fixed this problem by getting rid of bt878 card. No regrets but a lot of bad memories.

[zerowalker]

Well i don´t have Bt878, but cx2388x, though i can´t say it´s better or worse;S

But what card do you have now?
You sure it doesn´t have White Crush (or similar sync AGC thing)?

[juhok]

Blackmagic Decklink Studio. No AGC. Altho I'm just upgrading to Ensemble Designs BE75.

[zerowalker]

Okay i think the "Ensemble Designs BE75" is a Bit, out of my league, but it seems like some neat high end stuff, with TBC and 12bit etc

the Blackmagic is a bit to expensive as well, but it seemed High End itself as well.

But what is the difference in reality?
Except for being High End and all that, how come it doesn´t need White Crush and stuff?

I haven´t heard anyone else using those, everyone seem to go after c2388x or ATI Wonder.

[juhok]

I don't understand your question fully. Why would it need "White Crush". That's not even a standard term except for an one old card. I don't have any players (or material for that matter) than really goes over 255. It's never been an issue. With BT878 I had difficulties with proc amp etc and they were problems of the BT878 card, not problems of the VCR or Blackmagic etc. Why "everyone" here uses something else, ask them. If I had to guess: a) money b) go with the flow.

[zerowalker]

I though that White Crush was needed to "Control" The analogue signal well, especially VCR and stuff which aren´t the most stable signal.

But i don´t get why some card don´t need it, what happens to them?
Does it look better, more Luma or what?

[juhok]

Luma can be low if it's recorded like that, but it rarely if ever will overshoot the legal boundaries. It's not a jungle, the specs are there and VCRs follow them pretty well. Usually highest I get is 252 which then will be converted to legal 235 in post. If you want to "see" it, send me a tape and I'll give you a sample.

[zerowalker]

So you mean that my card "over use" the Luma, and isn´t really showing it in it´s Original state, and it needs the White Crush to "make it right"?

I think i understand enough, and well, don´t really want to send any of my old tapes, if you got some old cartoon movie/serie VHS, please say, maybe i also got it here, though another dub, but probably "same" image quality.

[sanlyn]

Ah, phooey! Getting that "Reported Attack PAge" message again for videohelp! Pain bthe . . . .
Message I was going to post is: working with the frames with White Crush turned "on", I used some Avisynth plugins to make them look fairly good. Would take some tweaking, but it seems to work with White Thingie "on". With the video as-is (no corrections during capture), the clip is petty useless. Maybe you could five it us a capture with White Guy on and the settings you used last time, but leave it on and see what we get. Can try working from there.

[zerowalker]

Ehm, didn´t really get what you meant there, do you want me to give you a sample with my "tweaked" settings, from that scene?

Cause i have the "tweaked" setting on the Cartoon samples i gave before, i can give it off there aswell if that would help us anything.

But i don´t really like using something that´s seems like it shouldn´t be there, i get the feeling that it messes around to much just to get the Luma right.

[sanlyn]

So you mean that my card "over use" the Luma, and isn´t really showing it in it´s Original state, and it needs the White Crush to "make it right"? .

We're saying that we need to see the video with no corrections. We have no idea what you're doing. You now say you used white crush control, but a lume setting as well? We need to go back to the beginning. Can you show us a cap of that clip with all the auto stuff turned off? If it's too dark,w e can advise. If it's too bright, we can advise. If you're using 2 or 3 auto filters and changing it, we have no idea what to tell you.

[zerowalker]

Okay, will give you a sample, i have been a bit to Uninformative, sorry for that!
I think i am used to seeing all these weird settings, and i just tell you some fast stuff, and you have no idea what i am doing, but i Think you do;P

But do you want, the Beach clip?

Just to say, that was Composite and from a Camcorder Video-8 (I don´t think that does any real difference, i think that Video-8 is a bit better than VHS, atleast with Chroma Leaking).

Or do you want the Cartoon (or anything else, Realistic, movement etc?) from a VHS?

[sanlyn]

Let's stick with the beach clip. If you would, turn everything off, have no "auto" controls running at all. Working with a filtered or modified source is impossible with problem clips. We'd like to see what the beach clip looks like with no modification. That's the only we way anyone can help.

[zerowalker]

Okay, here it is, it´s the start of the band (as you can see, it´s blue in the beginning, then it messes around).

And then it´s on, and the sand is to white.

The White Crush is OFF, and no other AGC (Chroma,Luma) is On either.

The Brightness and Contrast is exactly like i had in the previous clip, it shouldn´t clip at White, maybe at Black, but that´t the borders i think.

EDIT: as you can see, this clip has some Sick oversharpening, it´s really really bad.
And i don´t know if it´s the camcorder, the tape or the capture device.

[juhok]

So you mean that my card "over use" the Luma, and isn´t really showing it in it´s Original state, and it needs the White Crush to "make it right"?

I think i understand enough, and well, don´t really want to send any of my old tapes, if you got some old cartoon movie/serie VHS, please say, maybe i also got it here, though another dub, but probably "same" image quality.

I'm not a video engineer so this explanation could be nonsense. Your card is trying to do all sorts of automated gimmicks and there - in my experience - really isn't an "unity gain" option with it. It's always wrong one way or the another. For example my card was either too sharp, or too soft. There was nothing you could select inbetween. It had yellow color cast with default settings. Proc-amp gave weird results no matter what. <- And this was tested with different test charts, not just by random VHS. Blackmagic and other "broadcast spec" cards are set more to the "unity gain" and give as-is picture or like you say "Original State". It won't make your crappy VHS looks spectacular, it will just give you more accurate crap. If the VHS is recorded badly, blacks crushed and max luma 100, it will give you that. And like I said earlier usually these things don't overshoot.

I don't have animation or much anything else which wouldn't breach client confidentiality but here's an UTVideo compressed clip from one of my test tapes, Finding Neverland, finnish subs: http://siluriformes.net/videohelp/neverland_uly0.avi - pretty average commercial VHS quality.

[zerowalker]

If what you say it true, juhok, that it´s as i thought of it.
The White Crush is some stuff that just tries to Make it "Right",
and what i want (and all else probably) is just accurate capture, i don´t want Over sharpened, over saturated, to soft etc, i just want what my device gives me.

Then i want to Filter, tweak or encode it directly or whatever i wana do.

And a Capture Device can´t do anything better than software (Not always true of course, but in this "world" it´s very often true), Except Comb Filter and TBC as it is currently.

So we will see, if i just can find more trustworthy explanation of White Crush (not saying i don´t trust you, but as you said yourself, it´s more of a guess than on the papper).


But will see your commercial for the heck of it and see if it tells me something

EDIT:

Watched it, and well, i think it looks good, stable and the colors look good.

Now i am typicly blind to seeing bad colors and wrong luma except if it´s severe, so this doesn´t really say anything;S

But what i can say is, you got less over sharpening than me, i got over sharpening all the time, and i first thought it was the VCR, but now i am beginning to think it´s my card;S

[juhok]

^
Heh that VCR which was used is always on the border of being oversharpened. If I did JVC 9000 series capture it would be a lot softer. And I forgot to say, Blackmagic, BrightEye and other will give you proc-amp controls. But for example with Blackmagic it's better to use avisynth because their own filters suck - unity gain ftw. With BrightEyes proc-amp I'm not yet sure, in theory it could be better because of the higher bit-depth used. We will see.

[zerowalker]

Really?

Well eitehr i am blind, or well, i don´t know, cause i got some Sick over sharpening pretty much on everything;S

Though i do currently have Panasonic, which is famous for trying to get the "Best" picture, and will often sharp a bit much, but i did have the same problem with my old Sharp, so i am starting to blame my Capture card, but i can´t prove it yet;S

Wait, what did you mean with Unity Gain??

Hmm, interesting, Higher bit-depth can help, or well, it will help, many avisynth filters work at 16 bit, and get dithered to 8 bit, and even then it´s good.

[juhok]

By unity gain I meant "as-is". If you have a DVD player, get something like http://www.tvblink.com/i_down.html and compare the digital source to your capture card version (but keep in mind that DVD player may introduce artifacts of it's own).

[zerowalker]

Ah, i see, and yeah i understand it can´t be identical by any means, but it should be Identical- the analogue transfer (if the DVD does it job good).

But sadly, the PAL edition can´t be download, so i can´t test it for fun;S

[zerowalker]

Btw, here is an interesting site:

http://midimaker.narod.ru/eng/cx88/cx88prg.html

I myself am trying to get this modifying tool to work, but i can´t get it to do anything really.

But what´s interesting here are these:

WhiteCrushOff - allows to disable adaptive AGC (this allows to avoid slow brightness increasing and then fast returning to original brightness and in the case of too dark or too bright image)

CompClamp - this parameter allows in some situations to reduce "ringing" on sharp edges. Below is an example for 27 MHz videodecoder decoding rate (image is enlarged by nearest neiborhood method).

From my understanding, it seems like he says WhiteCrushOff is a good thing, that disabling it solves problems?

And CompClamp is something i would like to try, though i don´t really understand what it does, is there a side effect or what?

Comparator Clamp is the long word i think*

[sanlyn]

ds000.avi: There are no level changes in this clip. The color's good, but it's your player pumping up contrast that's causing the problems. Luma control just makes it worse, not better. And if the camera had AGC and level changes, the White Crush will make that worse, too. You control the over-hot whites by reducing contrast. Try lowering contrast about 20 to 30%, just until you see the bright (right-hand side) part of the line in the histogram draw inward within the borders (Ignore the black borders of the image itself, they will always be a black spike at the left-hand side).

I'll repeat the old rule: brightness controls black levels, contrast controls white levels. Just find a safe range inside the histogram, as well as you can, with contrast and brightness. Look at the histogram to see what those two controls are doing. Don't expect everything in between to be perfect; that part will never be perfect during analog capture, there is too much variation with tape.

Below is frame 80 of ds000. I made all the corrections in Avisynth with ColorYUV and SmoothLevels. Can clean edges and overshap later.

[Attachment 13674 - Click to enlarge]

[zerowalker]

ANd if the camkera had AGC and changed levels, the White Crush will make that worse, too.

Do you mean, when recorded or on playback?

Try lowering contrast about 20 to 30%, just until you see the bright (right-hand side) part of the line in the histogram draw inward within the borders )Ignore the black borders of the image itself, they will always be a black spike at the left-hand side).

I am pretty sure it´s withing the border (no clipping), but will lower it a bit more, but pretty certain that it won´t reveal any more details at all, just making the white "gray".

here is a sample with the same scene with lowered Contrast and Histogram attached.

[sanlyn]

ANd if the camkera had AGC and changed levels, the White Crush will make that worse, too.

Do you mean, when recorded or on playback.

I don't know if your camera has AGC or not. If so, it works when it records the original video. Doesn't usually work during camera playback.

[zerowalker]

I don't know if your camera has AGC or not. If so, it works when it records the original video. Doesn't usually work during camera playback.
Still Lookin'

Okay so you mean that the AGC is often Active when recording?

I can´t test it, as it isn´t left, but i would believe it had something, cause, the Whiteness on this tape is extremely bad, and i can´t believe my capture settings to be all the blame for it.

[sanlyn]

Either your player or your capture card (at its defaults) is burning up everything above RGB 180 or so, and keeping gamma too low below that range (upper midtones just don't show up in ds001. Look at details in the sand, many midrange details like footprints just don't show up in either ds001 or the earlier captures. Some of that detail is at about RGB 170 or 180. In ds001 everything abiove that point is burned away, so there's very littel fine detail in the sand. all you can see there are the darker rocks.

In ds002, the white crush control is smoothing gamma and apparently retrieving some bright detail around RGB 180 that is being lost in ds000 and ds001 (either by the player or by the capture device's defaults). I don't know if White Crush is changing any levels or colors, at least in ds002. But I wouldn't couple that control with any other auto features, it's doing well enough by itself. There is still a clipping point at aroiund RGB 200, but I think that's in the video itself. I wouldn't dare touch that Luma control, it looked disastrous on the earlier capture and made life very difficult.

ds002 looks much better. It can be tweaked, cleaned up a bit, and made to look more vibrant with any of a number of filters in VirtualDub or Avisynth. As long as the capture has everything intact, you can post-process to your heart's content.

Maybe a techy can look over that PDF and explain why white Crush retrieves high-end detail that is being burned away in the other captures.

[zerowalker]

Either your player or your capture card (at its defaults) is burning up everything above RGB 180 or so, and keeping gamma too low below that range (upper midtones just don't show up in ds001

This is the problem.

It must be the Capture Card, then it has this AGC that solves it (White Crush). But i don´t think it really solves it, just makes it look more properly, as why would it need an AGC to begin with, and why is the default settings to slow to even react, and in th end it has to be "dimmed" all the time to work good when scene changes to bright.

The problem with this is, i can´t capture intact, as White Crush is the thing controlling everything for me, and it will be hard post processing as White Crash is adaptive (even though i tweaked it to be pretty much on all the time, but i think it has some side effects).


Does anyone know anything why White Crush is needed?
I would really like to know that, if there is a real reason behind it, or is it just there because the Card doesn´t handle the Luma on it´s own.

[sanlyn]

Not being familiar with that card, I can't say. But its defaults are apparently causing problems. I have similar tapes that are horrible broadcasts to begin with, played on pretty decent Panasonics that still puimp the high end a bit. But I can control it in VirtualDub capture through my AllInWonder card by just lowering contrast a notch. There's no AGC in the player or card at all. So maybe there's another white level tweak in your card somewhere. If the AGC action is over-working, it might be possible to correct it with Avisynth or VirtualDub. It depends on how serious it is.

\Well, there's always a Hauppauge card . . . I just never get involved with any device that has AGC involved.

[zerowalker]

What card do you have?
As AllinWonder had Macrovision problems, and isn´t in PAL i think, which is why i have kept away from them a bit.

How are the controllers?
How much can you control etc, please print the menu.

And does it work with Windows 7 x64?

If the AGC action is over-working, it might be possible to correct it with Avisynth or VirtualDub. It depends on how serious it is.

Yes i know, but it shouldn´t be necessary, i mean, why should i capture with a card that makes more problems than what´s actually there?
And it can be hard to solve Adaptive stuff, and it won´t come without side effects which is making it worse.

[sanlyn]

What card do you have?
As AllinWonder had Macrovision problems, and isn´t in PAL i think, which is why i have kept away from them a bit.

How are the controllers?
How much can you control etc, please print the menu.

And does it work with Windows 7 x64?

I have two capture cards, AllInWonder 7500 and 9600XT. ATI made AIW's for NTSC and PAL. I use virtualdub for capture. If I have a macrovision tape, I feed it through a tbc or a DVD recorder pass-thru. For HD I'll soon be using a Hauppauge PVR but have to finish the PC for it. The AllInWonders don't run in 64-bit (which I don't have anyway), I built 2 XP machines for them. My new home-built PC is for higher-speed processing, AfterEffects, and the HD recordings I'll soon have with the Hauppage PVR. It's a home-built XP 32-bit machine -- no way I'm throwing away 10 years of software and hardware just to say I have 64-bits around. And two old, rebuilt DVD recorders.

If the AGC action is over-working, it might be possible to correct it with Avisynth or VirtualDub. It depends on how serious it is.

Yes i know, but it shouldn´t be necessary, i mean, why should i capture with a card that makes more problems than what´s actually there?
And it can be hard to solve Adaptive stuff, and it won´t come without side effects which is making it worse.

I can't say. I don't know how severe the level pumping is. Some plugins can help, Sometimes it's easy to fix, sometimes not. The need for that special White control might just be for certain tapes. I can't say. But in my own experience, I can play the same VHS tape on any of 3 VCR's and they all play differently, some better, some worse.