DVD lack?

Trent Nicholas (Tnicholas@vmfa.state.va.us)
Mon, 16 Oct 2000 10:37:29 -0700 (PDT)

Re: Pip Chodorov's DVD insights:
Does this mean the 12" Laserdiscs do not use compression technology and are
definitely superior to DVD? If so, perhaps the Laserdisc fans are still in
luck.
Thanks.
Trent Nicholas
Statewide Media Resource Coordinator
Virginia Museum of Fine Arts

-----Original Message-----
From: PipNY@aol.com [SMTP:PipNY@aol.com]
Sent: Sunday, October 15, 2000 1:44 PM
To: Multiple recipients of list
Subject: Re: Future DVD?

I'd just like to remind you all in light of this discussion what
I've already
tried to say before:
A DVD holds some 6GB of information. At 5 MB per second of
DigiBeta-quality video*, that means a disk can hold about 20 minutes
of true
video. Disks that contain 2 hours or more do so through MPEG
compression.
MPEG compression is a sytem by which elements that remain the same
in
consecutive frames are encoded. This means that the consumer is
receiving far
less raw information from the original film in DVD than in VHS. The
digital
resolution may be superior to magnetic VHS tape but the compression
removes
much more information. Try doing a freeze frame on a DVD of any
feature-length film and I think you will see that the grains are
replaced by
pixels.
I release video reproductions of experimental and avant-garde
films on
VHS. These films cannot be compressed, because often the consecutive
frames
are completely different from each other (Brakhage's hand-painted
films for
example). With DVD you are seeing at least 30% less of the film than
in VHS.
Why should any consumer accept this poor quality, regardless of
whether it's
Brakhage or Hitchcock? Until the technology gets better, DVD for me
as a
publisher is unacceptable, and by technology I don't mean better
compression,
but a format that brings you 24 frames per second of full screen
video with
no compression.
The industry hype about DVD being better is only a ploy to get
consumers to
spend more money on the films they have already bought.
VHS may seem poor quality, but it is a more faithful frame-by-frame
reproduction of the original film, and as a reproduction should in
any case
not be considered a replacement for Film. A black and white art book
can
still convey the power and genius of the original paintings - and
one should
still go to museums.
-Pip Chodorov

*DigiBeta is already compressed. One frame of video is 720x576x3
pixels (3
for RGB) in PAL and 720x486x3 pixels in NTSC. This means each frame
requires
about 1.25MB so full speed video would need 30MB per second. A DVD
at this
rate would hold 3 1/2 minutes. DigiBeta is compressed about 1:6
which is
almost unnoticeable, but this is intra-frame compression like JPEG,
not
inter-frame compression like MPEG. But in a perfect world, we could
have
formats equal in quality to film (each film frame holding about 12MB
of info,
288 MB per second.) At current DVD rates (2 hours on 6GB) there is
room for
only 35K per frame, 1/6th of Digibeta quality. So stick with film.

(ps If I am wrong about any of the numbers, math or current
technology here,
I certainly hope to be corrected - I have asked many technicians and
they all
confirm this info. They do however speak of a
double-sided-double-density-DVD
which holds 18 GB, or an hour of uncompressed video, but they all
say that
DVD is based on compression technology and must be compressed.)