Re: [tlug] Audio CD Issues

["Dmytro Koval'ov" <dmytro.kovalov@example.com>]

On Sun, 20 Mar 2005 13:27:20 +0900, Lyle (Hiroshi) Saxon
<ronfaxon@example.com> wrote:
> with current digital video formats) and it seemed apparent that the
> method of video tape "copy-guard" was simply to damage the video signal
> so that it was just barely within what the corrective circuitry of
> televisions could correct.  Thus, when you copied the tape, the signal
> fell below the threshold of correctable errors and you got a heavily
> damaged signal.  In the case of originally made tapes out of my cameras
> (four of them, all of which burned out with distressing speed and
> regularity), the picture went from looking great to crummy in just one
> generation (unavoidable with analogue editing).

Your impression about analog copy protection is wrong. There isn't any
correcting circuitry in television. On the opposite, there's a
"damaging" circuitry in any produced recently analog video device
(tape recorder, analog to digital converter etc.) It's licenced by
MacroVision and it's purpose is exactly this -- to damage video signal
when it detects some "special frequency", how they call it (I don't
know what kind of frequency or signal it is -- never went on to
finding details of it). That "special frequency" is added to all
commercial tapes (also licensed from MacroVision on a per-tape base).
That's why you can't copy them. You won't be able to copy DVD's on
analog device exactly for the same reason -- they have MacroVision
protection.

But you can copy your own tapes, because that frequency is not added
to them. Of course quality degrades with each copy of a tape (and also
ith each viewing), but that's different issue.

--Dmytro