Video auto gain control

Lajko wrote on 1/6/2003, 8:17 PM

I am talking a lot of old 3/4", Hi-8 and VHS tapes and loading them in to preserve them. Because these were shot with various consumer cameras and quality has degraded in some (some 20 years old).

To do a simple improvement, is there any auto-gain control for video? I really do not want to go scene by scene to improve family videos, but an auto gain would make them acceptable.

Also would be nice to have a drop-out removal filter. Stations use them and for those who don't know what it is, it is like a click & pop removal filer for audio. Those bright flecks from old video tape get cleaned up in one of various ways (adjacent lines, previous frame line, etc.)

Comments

seeker wrote on 1/8/2003, 12:41 AM

Patrick,

When you say auto-gain control, are you referring to the audio levels?

-- Seeker --

chary1 wrote on 1/8/2003, 1:22 AM

dear sir

please send me more details about videoauto gain

thank you

chary

pb wrote on 1/8/2003, 7:02 AM

You should be able to rent a "FOR A" frame synchronizer/TBC with a processor amp for not too much money. Even better, look on E-Bay for one. We also transfer VHS, U-Matic, 8mm/Hi8 to other formats using a routing switcher and a frame synchronizer. You can adjust chroma intensity, phase/hue, contrast and video level. Good unit to have, especially for old U-Matic shot with single tube cameras, which tends to have "blooming" reds. Only flaw is it will freeze frame a serious drop out, which means you have to keep your eye on the monitor.

BillyBoy wrote on 1/8/2003, 8:57 AM

Use the FX filters. Hardly a video goes by that I can't improve, sometmes dramatically by using Levels, HSL and Color Curves.

Summersond wrote on 1/8/2003, 12:23 PM

In addition to BillyBoys note, you could apply it to the whole track if the complete video file was incorrect, saving you from havint to go thru the complete file scene by scene correcting it.

my 2 cents worth,
dave

Lajko wrote on 1/13/2003, 7:36 PM

I am referring to the video. Basically, like your camcorder has an auto-iros/exposure setting, and your VCR's all use auto-gain on analog video input (that's why macrovision makes the picture go light & dark), I am looking for an automatic filter to do similar adjustments.

Remember that whe stuff I am transferring is not for production or professional use. It is for archiving lots of old tapes into digital, and doing some form of acceptable clean-up automatically. If I intend to use some of this old stuff for a production or even a family video, I would manually do a final adjustment of the clips used so they would all match.

I realize that handling the analog gain with an external hardware box would work better.

Drop-Outs: It would seem that someone would have a drop-out filter. That could help everyone tranferring from VHS, 8mm or beta tapes.

Hope this gives added info on what is needed and why.

Tyler.Durden wrote on 1/13/2003, 8:49 PM

Hi Patrick,

Your final recorder may have AGC... it is pretty common on JVC duplicators if you have one.

As for a standalone unit, most frame-syncs are a tweek as you go deal.

Dropout compensation is done at the vtr... it reads the RF coming off tape and fills in with black for the span where the media is missing. I don't think there is a device that can DOC a baseband signal. Pro VTRs with TBCs will have some kind of DOC.

HTH, MPH