Brightness fluctuation problems - capt from VHS thru ADVC110

[ChrisMtl]

Hello, I am converting analog video from VHS to an iMac OSX 10.4.8 via
firewire using a Canopus ADVC110 video converter. This unit has no TBC or DNR functions. The capturing software is iMovie HD ver 6.03.
The ADVC is also powered by the firewire bus, though there is an input for a DC adapter if need be. I am not using a DC adapter.

When viewing the converted video on the computer, the video
image constantly and cyclically dims and brightens. There is NO
copyguard on the VHS tapes, it occurs using BOTH composite and S-video
video cables and it also occurs no matter what video recorder I use as
the source (I tried two different ones, including an SVHS with built in TBC and DNR). Granted, it occurs less often on the SVHS with TBC and different VHS players produce varying degrees of the effect which is somewhat similar to viewing a copyguarded cassette yet less intense.
However, when I play this same video straight to a TV, the picture is just fine. Also, the brightness-drops tend to occur roughly in the same places on the tape. If I rewind the tape, it will dim in more-or-less the same spots over and over again.

Again, these are home-recorded tapes from television, there is no copyguard on them. The dip switches seem to be in the correct positions and changing them doesn't help.
Would anyone know what is causing the image fluctuation from dim to bright when using the
ADVC110 and if this can be remedied?

Thank you in advance.

[Rawit]

I'm experiencing something similar. I also use a Canopus ADVC110, to capture directly from the tuner of my TV (PAL territory).

Some captures from certain channels display some dimming here and there, it's also noticeable in the WinDV preview. The dimming isn't visible on the TV however.

I'm using the Canopus ADVC110 in combination with a stabilized DC adapter. The dimming occurs only with certain channels. The channels that dim look perfect on my TV, and show no signs of interference or weak signal strength.

I capture through the SCART socket of my TV, with a good quality composite video cable. When capturing from other sources (game consoles) I do not experience any problems.

Is the Canopus unit sensitive for certain interference? I also would like to hear if it can be solved, and why it is happening.

Thanks

[ChrisMtl]

Yes, that appears to be the same problem.

Oddly, switching to yet another VCR solved the problem temporarily, but now using this same VCR the problem seems to have returned. I'm thinking something along the lines of power problems or interference from some yet undetected source?

Does anyone know about such things?

[Rawit]

I also thought of power problems. Right now i use a stabilized DC adapter, because I'm using a laptop with a mini firewire connection. I will try to capture with my desktop (power by firewire), as soon as i get a longer firewire cable.

I'm going to get the VCR from the attic, and see if I get the same results with that tuner.

Although it seems like a power problem, it doesn't explain the effects only being on certain channels (in my case).

I'm going to test some things to find out what the problem is.

Edit: Tested with my VCR, the problem is still there, on the same channels.

[hip_school_preppie]

I'm so glad you guys posted this, as I too am having the same issue. I'm using a JVC SVHS > Canopus 110 (S-Video Connection) > Firewire > Dell Pentium 4. Using Sony Vegas 7.0 for capturing. The firewire is powering the Canopus. The thing that is weird for me is that the "random dimming" pretty much occurs at the exact same spot on the tape everytime. Also, I'm pretty sure it's capturing that way, as when I burn it to DVD and playback on my TV I can see the dimming. I have tried (I think) every setting on the Canopus and my vhs to curb the issue to no avail - what the heck is going on? It almost seems like there's some sort of auto brightness feature kicking in. We gots to figure this out. So annoying.

[Rawit]

We ruled out the power supply so far. I've tried power by firewire, and a stabilized adapter, but that doesn't make a difference.
Also, it appears when you capture tapes, the dimming occurs on the spots on the tape. That would mean the problem is signal related.
I captured from tv directly, by using the composite out on my tv, and on my vcr. Both sources display the dimming on exactly the same channels.
When I capture footage from a gaming console, I have no problems whatsoever. Also capturing a 20 year old VHS tape that has lot's of tear and wear, captures perfectly without dimming.
My guess is that the Canopus box is sensitive for a certain interference in the signal.

Question: Do you guys have any electronics around that may cause interference? I have a Onkyo Digital Amplifier, the manual states it can interfere when auto tuning radio stations. I use a different power outlet for my tv/amp and computer btw.

[edDV]

I've never seen these issues with the ADVC-100. My bet is the problem is in the incoming video. That is easily determined by monitoring with a non AGC monitor path or compare to a capture with a DV camcorder.

[hip_school_preppie]

I only have my pc, speakers, vcr and wireless antenna near by. I tried moving the canopus box like 4 feet away from everything, turned off the speakers, unplugged the wireless and still have the same issues.

I'm wondering if we've uncovered some sort of bug with the advc-110. Has anyone tried asking Canopus support, or ever dealt with them before?

[thecoalman]

I have a 110 too and can't say I've ever experienced this. The st robing affect you mention and everything else is practically identical to the trouble I had with a ATI AIW. The macrovision detection would kick in but not quite as bad as it would on a tape that had the real thing, however this very same tape captured flawlessly on the ADVC.

I do have a suggestion though, there's a button hack where you hold the input selection switch down for 10 seconds when you power the ADVC on. Don't know if it works with the 110 but a poster here states it does: https://forum.videohelp.com/viewtopic.php?p=1700812#1700812

What I would first suggest is trying it with commercial tape that you know has macrovision, this way you can determine if the button hack works on your model. If it does try it on your tapes. May or may not help but it won't cost you anything.

[Rawit]

Thanks! I will look into this. Have to find a commercial tape first. Do DVD's output macrovision enabled signals? It's easier for me to try that.

[hip_school_preppie]

That didn't help my situation. I put in a commercial tape, the macrovision light came on, I held down the button and it overrode the macrovision for that tape successfully. I put back in a tape that was giving me grief and it still had the same issues. Tried resetting the Macrovision override and that didn't resolve the issue.

One of the weird things is, it always happens in the same spot of the tape until I eject the tape and put it back in - then it will start happening in a different spot but over and over again in that same spot.

[Rawit]

One of the weird things is, it always happens in the same spot of the tape until I eject the tape and put it back in - then it will start happening in a different spot but over and over again in that same spot.

That's quite weird. I have the dimming issues with recording directly from tv, so not something i can test here instantly... I think I'm going to tape one of the channels that give me trouble, to see what results I get then.

[hip_school_preppie]

Just to rule out the VCR, I tried with an old school Sanyo using a composite connection and the same issue occurs. I hooked up both VCR's to my plasma tv and there's no "dimming" whatsoever.

If it were a Macrovision issue, wouldn't the 110's red light indicator turn on? Also, I would think if it were Macrovision, the issues would always occur in the same spot(s) or all the time, not just here and there. I wonder if the 110 has some sensitivity issues with tape playback - like, if the tape or signal being passed to it has some sort of degradation it tries to compensate for it, or just starts to "flutter" the contrast. I definitely don't think there's a connection issue.

[captaincanadapirate]

Thanks! I will look into this. Have to find a commercial tape first. Do DVD's output macrovision enabled signals? It's easier for me to try that.

in a way dvd's that are copyprotected will emit the analogue copy-protection. However dvd copy protection is different from VHS copy protection.
DVD copy protection is not encoded in the video signal like VHS. Infact The DVD has a serialcode that matches to the Copy Protection device that is inside your DVD player. This little microchip picks up on DVD's that are encoded with this serial number and then turns macrovison on. Now DVD macrovision has what is called color stripping. You can stabelize the copy protection with some old vhs stabelizers but among playback on vhs tapes you will see blue or red lines horzontally down the picture.
Some DVD players may have macrovision disabled. Other DVD players may have a manufactures hidden codes that will access hidden menus such as Region Code and or Macrovision on or off settings. You can find some of those on this site.

[hip_school_preppie]

Anyone have more information on this? I know my issue definitely is not related to Macrovision/copy protection. I tested with store bought TDK tapes - recorded TV shows to them and played them back on my TV w/o any issues whatsoever. I then try to play/capture the vhs tape through my advc-110 and the "dimming" randomly occurs.

So the question is - do all ADVC-110's have some sort of sensitivity issue, or does mine just have a bug?

[Rawit]

Hey guys... I finally got some time to do a test. I recorded a commercial from TV, with the Canopus ADVC110, a JVC VCR, and the DVR. The recordings of the VCR and DVR I also captured with the Canopus ADVC110.

These are the results (XVID, interlaced encoding):

EDIT: - Samples removed -

As you can see, the capture directly from tv is the one who fluctuates. The capture from the vcr (although noisy) and the capture from the dvr are fine. I recorded the footage with the vcr on another TV set then the one that gives me the fluctuation. I will test the vcr on that tv/cable outlet when I have more time.

Let me know what you think of this.

[JohnA22]

The macrovision detection would kick in ....What I would first suggest is trying it with commercial tape that you know has macrovision, ....

Pls, what is this microvision all about?

Thx- JohnA22

[JohnA22]

...by monitoring with a non AGC monitor path.... .

Pls, what did u refer to as non AGC monitor path?

Cheers
JohnA22

[edDV]

...by monitoring with a non AGC monitor path.... .

Pls, what did u refer to as non AGC monitor path?

Cheers
JohnA22

That means a monitor that doesn't self adjust to level variations.