Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!Teknowledge.COM!unix!hplabs!hpfcso!hpldola!paul
From: paul@hpldola.HP.COM (Paul Bame)
Newsgroups: comp.graphics
Subject: Re: Workstations that can record/play realtime video
Message-ID: <11390024@hpldola.HP.COM>
Date: 15 Nov 89 18:06:06 GMT
References: <1593@ndmath.UUCP>
Organization: HP Elec. Design Div. -ColoSpgs
Lines: 17

> VHS quality 24 bits x 640 pixels x 480 lines x 30 Hertz x 3600 seconds
> is 100 gigabytes uncompressed.

Somewhere there is a recomendation regarding how many bits and at what
speeds to do "broadcast-quality" NTSC digital video - and it's a heck
of a lot less than 24 effective bits per pixel.  For example, remember
that limitations of NTSC prevent one from changing color too awful much
within a single scan line - I think the NTSC digital stuff had the
crominance separately recorded at a slower speed than the luminance.
Wish I had the reference - if you're really interested I know someone
who can probably find it.  I think we were calculating being able to
put 1-3 minutes of video on a 125Mbyte (HP7925) disc drive (including the
magic to get it off the disc fast enough to record - which we never
found the time to implement).


	-Paul