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Re: digitizing - WARNING , TECHNICAL POSTING!!



Well I will take a crack at the second and third questions.............
 >What is the standard  frame size for digitizing bestasp?
I presume we are talking about Betacam SP which is an ANALOG component video
format. There are standard frame sizes in terms of the TIMING of individual
lines and frames in the NTSC and PAL video formats. As a video recorder
BetaSp will record video that meet these standards - so it is not the
machine that determines the frame rate - it is the signal that goes INTO the
machine. The recorder just records what is fed to it. If a non-standard
signal is fed to it, it will record a non-standard signal (and then have
great trouble trying to play it back).

The frame sizes are defined by the amount of lines in a picture in the
vertical domain and the length of each line (time) in the horizontal
domain - so the first thing to consider is that we are in the analog world
here - not the digital one - so the standards are in the analog domain.
Having said that there are both fields and frames in video - a frame is two
interlaced fields (so the frame is not the smallest unit - the field is) -
and the frame rate for NTSC is actually a bit less then 30 frames per second
and  PAL is 24. There is no frame "size" per se - if you watched television
on a projection television it would be much bigger then on a 17" television
or on the 6" ones on the back of the seats of airplanes these days. Shooting
from the hip and not looking it up there are around 485.5 visible lines in
the video frame in NTSC (top to bottom) and in PAL the entire raster is
composed of 625 lines. In the horizontal domain you can digitize the signal
at what ever resolution you wish - but for broadcast quality the number is
usually 768 points across. Color space is an entirely different discussion.

> What are the sound & image decompression standards for digitized betasp?

Betasp is NOT a digital format and further it is not compressed since it is
analog. I could get VERY technical and mention that indeed luminance and
chrominance channels are compressed in the analog domain as a result of the
NTSC or PAL specification but I don't believe that this is what you are
asking. As far as digitization of video there are multiple standards
depending on which way you are compressing the information. Currently there
are two main groups of standards that are used. MJPEG is one - and there are
multiple resolutions and aspects of that standard, and MPEG is the other -
and there are MANY of those also.

Having said all this - and no doubt being far more technical then you wanted
to hear (sorry but you asked technical questions which require a technical
answer) - it is important to understand a few things about video compression
and digitization. For one - most video compression formats are lossy formats
in that the process of compression intentionally loses or throws out
information. The second major factor is that most digital video formats are
NOT frame by frame digitization formats in which you have a given resolution
in x and y - rather the analog waveform itself is digitized at a given
sampling rate and bit depth - and there are differences for the luminance
and chrominance channels.

For an easy to read explanation of how television works check out:
http://www.howstuffworks.com/tv.htm

hope this helps.
jim

Jim Lindner
VidiPax - The Magnetic Media Restoration Company

Minister of Preservation and Access
VP General Manager VidiPax Division -
Loudeye Technologies
450 West 31 Street
New York, N.Y.  10001
212-563-1999 ext. 102

www.vidipax.com
Moderator: AV Media Matters Listserve
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> -----Original Message-----
> From: Archives & Archivists [mailto:ARCHIVES@LISTSERV.MUOHIO.EDU]On
> Behalf Of heidi
> Sent: Friday, October 27, 2000 3:19 PM
> To: ARCHIVES@LISTSERV.MUOHIO.EDU
> Subject: digitizing
>
>
> I have three questions:
>
> What is the standard cost for digitizing an 8-1/2" x 11" b&w image & a 5
> x 7" image?
>
> What is the standard  frame size for digitizing bestasp?
>

>
>
>
> Thank you for your attention to my questions.
>
> Heidi Connor
>
> A posting from the Archives & Archivists LISTSERV List!
>
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>
> Problems?  Send e-mail to Robert F Schmidt <rschmidt@lib.muohio.edu>
>

A posting from the Archives & Archivists LISTSERV List!

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Problems?  Send e-mail to Robert F Schmidt <rschmidt@lib.muohio.edu>