Posted by PTravel on 01/12/14 11:52

"Richard Crowley" <richard.7.crowley@intel.com> wrote in message
news:e8u220$333$1@news01.intel.com...
> ptravel wrote ...
>> No -- drop out is obvious when it occurs.
>
> Only the gross, uncorrectable dropouts (and mis-tracking
> and interchange differences, and many other factors which
> affect ability to read/decode digital data from tape) are
> "obvious" For every "obvious" problem you see, there are
> likely 100 that are either completely reconstructed, or at
> least reconstructed good enough that they are not "obvious".

And if it's completely reconstructed, then there is no data lost and no
"generational loss."


>
>> DV cameras don't replace drop-out with anything,
>
> Technically, they do. What we see as "large pixelization"
> is actually replacing a bunch of individual pixels with some
> "average" value for that portion of the frame because the
> individual pixel values can't be recovered or reconstructed.

Okay.

>
> Back in the analog days, "replace" meant "temporal" repacement,
> where a pixel would be replaced with the same pixel from the
> previous frame, etc. With digital, a pixel is more likely to be
> replaced with the one next to it (because that is easier/faster
> in the digital circuitry)

We're still talking about apples and oranges -- data reconstructed using ECC
is accurate and bit-for-bit what was recorded (or supposed to have been
recorded). Replacing pixels (or scan lines or averaging blocks) results in
lost data.

>
>

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