What type of TBC will fix this type of wiggling in the video?

[jagabo]

From the waveform graph I posted earlier it looks like there was more dark detail in the area I marked in red here:



That represents the characters black hair. That solid, sharp white line just above the red indicates that there were darker pixels but something along the capture path crushed them. You might be able to adjust the capture device's brightness and contrast settings to prevent that crushing. Or it might be happening earlier in the chain, maybe in the VCR's processing (disable all filtering in the VCR if you can). If it happened before the VHS recording there is nothing you can do about it.

Regarding the meaning of contrast and brightness, different devices use those terms to mean different things. You'll just have to fiddle with them to see what you can get.

[sanlyn]

Usually -- I emphasize usually, conforming to the usual standard and considering how most video and photo apps and monitors work -- brightness is a confusing term. Most of its action controls the brightness of the darkest colors (sets the black level). Although most brightness controls will affect lighter values as well, it is used to raise or lower the darks. Contrast has most of its action at the bright part of the spectrum; it is used to raise or lower the brightest values (the white levels). In practice, brightness and contrast interact somewhat, so you have to fiddle a bit to get things right.

[jagabo]

In the analog days you had an offset (shift the waveform graph up or down) and a gain (stretch the waveform graph vertically) because that's the way the circuitry worked. What they called those functions varied. Brightness, contrast, picture, etc. With digital now there's even more confusion as you can logically do whatever you want to the signal.

[ChibiBoi]

Thanks for all the help! I've made a comparison of a tape that I captured, experimenting with the different VCR outputs.

http://www.mediafire.com/?ve5l59986hx56xx <-- This is from my Panasonic PV-VS4820, which is what my other samples were capped from. Notice how the brightness adjusts itself. I have searched and it seems that there isn't a way to disable this feature.

http://www.mediafire.com/?sma3s4avw1d95sc <-- This is from my Panasonic AG-1970, which doesn't seem to adjust the brightness, but it has its own set of problems... For whatever reason, the picture is super wiggly and its Hi-Fi audio conversion is not as good as my other VCR.

I may have to get a new VCR altogether, and I've checked on eBay, it seems like someone is selling an AG-1980, but it has this thing going:

According to the seller, the noise appears in dark scenes. And there's an uploaded sample from that VCR here http://www.youtube.com/watch?v=YobEPX-wo8w

[jagabo]

What are you capturing with? Maybe the capture device is causing the automatic gain problems.

[ChibiBoi]

What are you capturing with? Maybe the capture device is causing the automatic gain problems.

I have a StarTech SVID2USB2 and I capture on my laptop, but I'm pretty sure it's not the device that's causing the issue. If you take a look at the two samples in my previous post, they're both from the same SVHS tape, captured using the same device, but you'll notice the PV-V4820's levels fluctuate while the AG-1970's stays much more constant.

[jagabo]

Yes, but if the AG-1970 is running a time base corrector it has cleaner horizontal sync pulses (though it appears to have other problems). Horizontal sync pulses are sometimes used by the AGC circuitry to gauge how much gain the signal needs (the amplitude of the sync pulse decreases along with the amplitude of the picture signal).

I don't know if the StarTech SVID2USB2 is known for AGC problems. The ATI Theater 650/750 devices have AGC problems.

[ChibiBoi]

Yes, but if the AG-1970 is running a time base corrector it has cleaner horizontal sync pulses (though it appears to have other problems). Horizontal sync pulses are sometimes used by the AGC circuitry to gauge how much gain the signal needs (the amplitude of the sync pulse decreases along with the amplitude of the picture signal).

I don't know if the StarTech SVID2USB2 is known for AGC problems. The ATI Theater 650/750 devices have AGC problems.

It doesn't seem to have AGC problems from what I searched on Google. As far as I know, my device is pretty streamlined. I ended up getting a Pioneer ES15 to use as a passthrough, would its TBC give me cleaner horizontal sync pulses like my AG-1970? If so, I will test it out once I get it to see if the gain changes by itself like that.

Also, what could be the cause of the diagonal noise in the AG-1980 that I found on eBay? It's selling at $75 and if it's an easy fix, I'll likely buy it.

EDIT: Looks like I found the answer to my last question in this post so I guess I'll have to either look for another seller, or look for another model. I've just upgraded my drivers for my capture device as well, I read that may cause some gain issues, but we'll see...

[jagabo]

getting a Pioneer ES15 to use as a passthrough, would its TBC give me cleaner horizontal sync pulses like my AG-1970?

It should. Like and device though it's not perfect and some tapes will still have problems.

If so, I will test it out once I get it to see if the gain changes by itself like that.

The levels changes through the ES15 are very minor. Nothing to worry about.