Canopus advc-100 giving weird colors

[mohamed]

Hi,

I came across a Canopus advc-100 device that has some color issues. At first it only happened occasionally and restarting the device several times would fix it, but now it happens very frequently.

I have attached a short sample while the colors are changing, once the colors go bad, they remain like this for a while and just occasionally come back to normal for few seconds.

Tried with several different S-VHS VCRs, issue still happens. Also it's worth noting the issue only happens if the tape is a VHS tape. if it an S-VHS tape, the issue goes away.

Any ideas on what might be causing the issue?

Thanks in advance for any help

[DB83]

Also it's worth noting the issue only happens if the tape is a VHS tape. if it an S-VHS tape, the issue goes away.

That throw-away line could be the clue to the answer.


Are these VHS tapes, by any chance, commercial ones ? S-VHS tapes , AFAIK, were never used for commercial releases.


The 'fault' to my eyes is copy-protection (macrovision) signals on the tape - but maybe just weak signals that create a false type of macrovision

[mohamed]

Are these VHS tapes, by any chance, commercial ones ?

The VHS tapes I have are all indeed commercial. The S-VHS is is probably some home recoding, I don't know the origin of the tape but it contain some news, something that would never be officially released on tapes, so yeah probably an issue with macrovision as you mentioned...

[jagabo]

It won't look great with some material but it's not completely hopeless if you don't mind putting in the work:

AviSource("output-sample.avi") 

a = Trim(0,111)
b = Trim(113,0).SmoothTweak(contrast=8.5, brightness=-290) # alternate fix: ColorYUV(gain_y=1900, off_y=-406)

a+b

[mohamed]

Hmmm, good workaround, thanks for sharing!

Still curious to figure what the actual solution (device-side) might be...

Also I guess even if I fix the video with avisynth it will be inferior to if I get with right colors since the beginning, right? (don't mind the fact that I might have to re-encode as a lossless codec could be used)

[jagabo]

Still curious to figure what the actual solution (device-side) might be...

A Macrovision stripper may work. A professional full frame TBC will work but will run US$1000+.

Also I guess even if I fix the video with avisynth it will be inferior to if I get with right colors since the beginning, right?

Yes. Smooth gradients will be posterized. And there's a loss of low contrast detail. You can see the difference between frames 111 and 112 in the sample I uploaded.

[mohamed]

A Macrovision stripper may work. A professional full frame TBC will work but will run US$1000+.

Thanks for the tip.

Actually the "2000" you wrote before the edit seems to be more accurate checked digitalfaq marketplace but they were selling for 1.5k+

I happen to have some device that will do the job for macrovision, but haven't used it since a while, I will give it a try.

But I think this might be the time I ditch the Canopus and get something else. I was just curious to know if it fixable, because this Canopus was able to bypass macrovision until just recently, but it suddenly broke without any reason...

[Eric-jan]

This ADVC100 hasn't the Macrovision option ? pushing (and hold) the silver button, will defeat Macrovision.
https://forums.afterdawn.com/threads/mini-faq-macrovision-cheat-for-the-canopus-advc100.290888/
https://forum.videohelp.com/threads/233261-Canopus-ADVC-100-vs-Canopus-ADVC-110

[lordsmurf]

Unfortunately, none of those "Macrovision removers" ever work well. Those items mess with luma especially, and the picture usually randomly brightens or darkens. It's badly responding to the anti-copy pulses. Yes, it's at least viewable now, but the quality is still crappy. For example, Grex is really crappy with videotapes (but good for digital protection, such as anti-copy from cable boxes).

Nobody likes buying TBCs. Same goes for lawnmowers (unless you're a redneck like Hank Hill). But it's a tool we need for this video conversion task. So we suck it up, get it, and then do the task we set out to do. Remember: buy it, use it, resell it. The gear holds value. If you're a short-term user, just some projects to get through, do that. If you try to go cheap, and use half-ass hardware, you're just making yourself miserable, and it'll result in lower quality. With the right gear, these conversion projects are easier, quicker.

Certain ADVC-100 models, or even cards that "ignore" MV, are still susceptible to anti-copy signals. Those are artificial video errors that mess with the signal in many way. So, for example, the wrong exposure (too dark, too bright) is still possible on the converted tape. Because again, no frame TBC. (Some tapes are so nasty that even TBCs have a hard time, but thankfully those are less common. It's mostly due to sloppy anti-copy injection, not anything intentional. Those same tapes would even have issues playing from VCR to CRT TV way back when.)

Avisynth won't do much here. Avisynth is ideally for fixing problems after a good capture. Not trying to fix a bad capture.

[mohamed]

@Eric-jan, thanks, it is exactly the link you sent that solved the issue.

@lordsmurf, I perfectly understand what you're saying, but I was not talking about doing a good capture, I know the Canopus is not the best and it is not my main capture device, it is not even mine, this one is a unit I borrowed. I was mainly asking, why did the Canopus, that used to work, suddenly act up on the same tapes, and the answer was simply because I probably messed up the buttons and I needed to do this trick again