Re: Future DVD?
Sun, 15 Oct 2000 10:44:47 -0700 (PDT)
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
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
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.
*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.)