In article , Lawrence
Glickman wrote:




For rendering analog video into digital video, as TM suggested, I
haven't explored that yet. Not sure I have enough interest in doing
so to justify the investment in time and money.

Maybe DVD is more permanent than tape, but it isn't forever.
Delamination is a problem, along with the growth of anaerobic
organisms that attack the media. I think you will be lucky to get 5
years out of DVD even if it is stored in a controlled environment.
The stuff isn't as archival as people would lead you to believe.

I have DVDs older than this, with no delamination or "rust." I usually
put critical files onto two different brands of DVD, with the
assumption that while one may have problems, the chances of both
failing in the first N years are low (pace the Poisson distribution).

My friend makes DVDs of videos for two reasons:

1. Randomly-accessible viewing, with chapters, titles, etc. A lot
faster than fast-forwarding through a tape. (Even more so with DV, as
few people have DV decks, just DV camcorders. The wear and tear on a DV
camcorder used as a playback deck is an excellent reason to make DVDs!
And store the DV as an archival "safe" version.)

2. Mainly he does the rendering (the overnight rendering I mentioned)
so that he has the source he can quickly burn onto a DVD+R (or -R, his
does both) for a parent of one of the kids in the baseball and football
programs he makes videos of. The cost of a blank DVD+R is about 50
cents, a VHS tape is more. And even more importantly, a DVD+R can be
burned in about 15-30 minutes, depending on length and burn speed, but
a VHS tape take 1-2 hours, depending on the length of the source.\

As I said, and as the article I referenced said, rendering either
home-edited video or non-digital-sourced video into a form that can be
written to DVD is notoriously time-consuming. Many sites say "Your
15-minute home video may take hours to render, even on a fast PC."
Which was my point.

Your point that you can do 130 factorial, or whatever, faster than you
need to, is not the point. Nor is it that you now have a 2.5 GHz
Celeron. My point was to refute your claim that fast PCs are not needed
for everyday use. They are. As for my friend, he also worked at Intel,
and he has 5 or 6 PCs. That he is rendering on one of his 1 GHz
machines is beside the point. The point is that rendering is
exorbitantly CPU-intensive, whether it takes 11 hours or 5 hours or 2
hours or even 10 minutes (for some professional folks, even this is too
slow, for obvious time value of money reasons).

(And, yeah, I can do 130!, in Lisp, Scheme, Mathematica, or Haskell. In
full bignum precision, needless to say. Both tail-recursion optimizing
for a recursive version, or, of course, the brute force 130 * 120 * 128
* 127... version. Mostly I now favor Haskell. See the Net for details
on why.)

Personally, I dump my DV videos directly through a Firewire port into
my Philips standalone deck burner, whose codec is set up for real time
streaming of digital data. This means no fancy editing of titles, jump
cuts, or even deletions, but it creates an archival copy of a 1-hour DV
tape in 1 hour. No muss or fuss. It's a DVD+R and DVD+RW deck.

My iMac has a DVD-R and DVD-RW burner, which is suitable for writing
content after editing or digitizing. I never use it, as I haven't used
the (admittedly sophisticated) features of iMovie (or its pro-grade
versions like FinalCutPro) to edit my home movies, insert fancy titles,
insert soundtracks, and then burn to DVD. This would presumably require
rendering times comparable to what my friend is seeing, e.g., several
times the length of the original per gigahertz of CPU speeed, e.g.,
overnight for a 2-hour piece of source material.

As for your 2.5 GHz Celeron making a DVD bit copy at high speeds,
congratulations. Except you should realize that bit copies are
basically made at the writing speed of your DVD burner. So if your
burner writes at 12x, a 2-hour standard DVD gets copied in 20 minutes.
Whether your CPU runs at 2.5 GHz or at 1 GHz. Think about it.

Rendering is not the same thing as bit copying.


--Tim May