time base errors

[Morgoth]

I am experiencing what I presume are time base errors on an old vhs I am trying to capture using avi_io on win98 with a matrox g200 marvel (uk). The symptom is repeated interference that shows on the capture screen but not on the TV. I recently bought a cheap video stabilizer (cypress cp-2s from maplins) which allegedly deals with time base problems, but it doesn't seem to have made any difference. I have two questions, if anyone can answer I would be very appreciative:

First of all, is it worth having such a device in line when capturing, just to clean the signal up a little?

Secondly, if I was capturing using a dv bridge such as the advc-100, would I still get such a problem?

thanks,

morgoth

[bubu]

I am not sure whether what you are experiencing is timebase problem... because I know very little of what really it time base problem is... When I had a audio-video sync problem, someone says that it was time base problem. Due to lack of knowing any better, i believe it.

I am using digital system converter to capture in NTSC format PAL/SECAM video and it touts it has time base correction capability integrated in it. I don't know if it is a reason but the results are pretty positive.

I don't know your video stabiliser, but I know that some of such products effectively kills macrovision "fading" effects. I never copy macrovision enabled video so I don't need it but other than that, I see very little benefits.

I haven't tried external DV converter just yet... I am hoping it does because I have a video that plays normally on TV, but when captured, it has frame dropping effect (jerky movement). I want to capture it clean and nice...

[Brian Ellis]

What you are almost surely seeing is the result of copy protection. I bet you are trying to rip commercial tapes???

I believe most analogue>DV bridges will have the same effect. That having been said, I know that early ADVC-100s had a means of getting round the protection but this has not been documented. I have heard, but cannot confirm, that Canopus have since disabled the said means. If you want to try it, just keep the button pressed for 20 seconds to bypass the copy protection. No guarantee.

[Morgoth]

I know this is not a macro vision effect - this is a copy of a commercial tape - the original went up in smoke in a flat fire!
(Still at least the chinchilla got out) - but it is an old bbc video tape circa 1990 ish. Its a sci fi series called star cops the bbc did.

I don't think they had macro in those times, or even now maybe. Plus macro usually shifted the brightness or colour balance in those days, nothing else.

Wondered if it was time base because I could not see anything on the tv as a problem. Very odd. Even when I copy the tape to another tape, the copy plays fine on TV but the marvel inputs drop frames and have bad interference etc on picture - white jagged lightning flashes for want of a better description.

I know that the stabilizer knocks out macro also by the way, so I am 99.99 per cent certain its not macro.

thanks,

morgoth

[bubu]

Just a update to my previous post:

I picked up USB2DVD (ADS system) at ebay and hooked up with my VCR and PC. the MPEG2 capture with it of the video that had jitter capture problem with MarvelG400TV+Videostudio setup, went well.

This equipment is simple hardware MPEG2 capture device, max bitrate is 5Mbps, transmitted via USB1.1 to PC. Nothing extraordinary (rather old timer material) and I am sure that there are many more products that are much better than this available out there.

Color balance/ hue/ bright/ darkness control is much more precise and controllable than marvelG400TV. and Rendering time is much shorter thanks to smart rendering in Videostudio, compared to MJPEG to MPEG2 conversion. I don't have to worry about frame drops either (very few compared with G400TV+videostudio direct MPEG2 capture)

Morgoth, I am with you on your idea that you want to pick up DV converter, after having seeing a good result of hardware conversion on my side....