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Posted by Martin Heffels on 10/01/85 11:53
On Tue, 11 Jul 2006 05:39:33 GMT, "PTravel" <ptravel@travelersvideo.com>
wrote:
>Actually, I did miss it but I've looked at it now. And, of course, it's not
>an answer to my question, which is "how often does an uncorrectable error
>occur"? You say, it's likely 99.99% of the time it's correctable. I say,
>I haven't seen the statistic anywhere, so it might be 9% or it might be
>99.99999999%.
You can answer that question based on your own experience of course. What
these numbers tell you is that there is a lot happenening that you don't
even notice, repaired unnoticeable to you, but noticeable to the player.
>Sorry, but that's a cop out. Again, the context of this discussion is
>whether DV experiences generational loss. All your (and Martin's)
>discussion has been theoretical and unquantified.
Yes, for an end-user, this seems to be a perfect world, where nothing
happens, but for an engineer who is designing tapes, and players, it is a
nightmare and they will tell you different.
Think about it: 100 drop-outs per minute. They won't all be correcteable,
so repair will take place by copying/interpolating data. Seeing the amoun,
I really start to believe that every copy you make, you loose data and thus
you loose a generation.
>This is no different than
>Martin's mpeg2 rants, when he claims that mpeg is "capable" of better video
>performance than DV-codec.
Ha! You haven't forgotten that one. Still haven't delved into this deeper?
Many more articles written about this with the arrival of HDV which tells
you I am right.
>Of course, since the discussion is always in the
>context of whether a consumer DVD camcorder will produce better video than a
>comparable miniDV camcorder, his answer, while technically correct, is
>misleading and inapplicable to the question. Similarly, here, the question
>was whether DV experiences generational loss in the context of making dubs
>and as compared to analog video. Without quantifying the uncorrectable data
>rate, claiming that "mitigated" data correction (for lack of a better term)
>equates to generational loss is, while technically accurate, misleading and
>inapplicable to the question.
Typical lawyer answer: not guilty until proved ;-)
>If the uncorrectable data rate is sufficiently high, then describing the
>effect as generational loss is accurate. If the rate is miniscule, then it
>is not. Unless I know the rate, I can't tell which it is.
I will keep looking for some more data. But maybe I am wasting my time,
because you haven't even bothered to follow the links I posted in my
previous message. So whatever I find, I will keep for myself, and maybe
share it with mr Crowley, and Craig the Tapeguy, and let you live in your
perfect world, so you don't have to worry too much. It might distract you
from shooting your nice city-footage ;-)
>That means that 99.99999975% of the time, the data is accurate, i.e. a
>bit-for-bit copy.
That is not a bit-for-bit copy, because that would be 100%!
cheers
-martin-
--
"If he can he'll smile 'cos he's a Royal Crocodile."
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