I’ve been gradually converting our VHS tapes to DVD, using a Canopus card to digitize the output.
Std Disclaimer: I am not pirating anything. We own the VHS tapes. We could keep them forever. But they take up a lot more room than DVDs and you have to rewind them and some of the home-recorded ones have commercials we want to omit. The resulting DVDs are for our own use only. & etc.
So there’s a pretty decent handful of VHS tapes that will not digitize properly. They all exhibit the exact same behavior: The iMovie input window will show it playing along for a few frames that look normal and then the video goes much darker. Plays for a few frames that way then pops back to normal. Oscillates between the two. Digitized results are unwatchable.
Not all commercial VHS tapes do this but all the tape that do this happen to be commercial VHS tapes.
I can see why, in the general spirit and tone of the board, it might be deemed a bad idea to have a protected conversation about how one might circumvent copy protection on a VHS tape if such exists, so let’s be clear up front that I’m not asking that. It’s a more fundamental question: is there, in fact, copy protection on a VHS tape that could be doing this?
Anyway, yes, it’s a form of analog copy protection called Macrovision which is embedded in the sync signal. It makes the resulting copy essentially unwatchable by spoofing the automatic gain control circuitry into thinking the brightness level is fluctuating wildly. The false brightness changes faster than the circuit can keep upso the image goes from way to bright to way too dark over and over. It was originally designed to prevent VCR-to-VCR copying; modern DVD recorders don’t need an AGC but in order to honor the Macrovision protection, nearly all machines include circuitry to mimic it.
Yes, it’s called Macrovision. It inserts pulses into signal lines that are normally outside of the viewing area. When you try to copy it through a VCR, the automatic gain control will overcompensate for the changing level of brightness and you’ll get the familiar patches of dark image/bright image.
This is not intended as a hijack, but what’s the advantage of copying a commercial VHS film to DVD rather than simply buying the film on DVD? I guess there’s a cost issue, but only if you discount your own time. Besides, the image on a new DVD will be significantly better quality that a VHS transfer. On a moderate-sized flat screen, I’d think it would be close to unwatchable.
Not everything that was ever issued on VHS is available on DVD. I have a commercial set of VHS tapes of the BBC series “Poldark,” which I would love to replace with DVD. However, it was never released on Region 1 DVDS, just Region 2 (presumably because the series is better remembered in the UK than it is in the US).
Oh, I’m well aware of that. As a film buff, I can report that there are still three films that won the Best Picture Oscar hat haven’t been released on DVD. But I guess my question in this case was why transfer them to DVD rather than simply continuing to watch them on the original VHS? The transfer process is going to degrade both the image and the sound quality. if your goal is simply to get rid of your VCR, his would seem to be an argument against it.
Well, I can’t speak for the OP, and while I will grant that some image and sound quality loss will occur, my rationales for “ripping” a VHS to a DVD would include the following:
[ul]
[li]Ability to insert chapter stops for instant scene access[/li][li]Decreased wear-and-tear on an inherently more wear-and-tear-sensitive media[/li][li]Eliminating the risk of the VCR eating the tape[/li][/ul]
And, as answered above, there is Macrovision protection (or at least MIMICED protection on VCR->DVD recorders).
There are admittedly ways of questionable legality via the internet to get the movies in file format and then burn them from there, but that would probably fall under the category of copyright circumvention as well so I’ll keep my trap shut.
I know what I need to know. It really is copy protection and not something I’m doing wrong. Thanks.
As to degradation, for the most part the digital file captures the quality of the performance of the analog tape at the time it’s playing (including any flickers, skips, cat hairs on the tape, etc). Most of our commercial tapes are the sort of fare you’d find on Turner Classic Movies — black and white vintage stuff from 1920-1950. As such, the quality that’s actually ON a VHS tape isn’t generally spectacular. For the ones that are important to us, and available as such, we do buy them directly as DVDs. But some are the sort that we only watch once or twice a year.
Technically speaking, I suppose there’s an inevitable loss of information when digitizing an analog stream, but it’s not such that we can notice it.
