Newsgroups: comp.multimedia
Path: utzoo!utgpu!cunews!dgbt!rick.doc.ca!calvin.doc.ca!andrew
From: andrew@calvin.doc.ca (Andrew Patrick)
Subject: Re: DVI questions
Message-ID: <1991Feb27.222824.6451@rick.doc.ca>
Sender: news@rick.doc.ca
Nntp-Posting-Host: calvin.doc.ca
Organization: Communications Research Centre, Ottawa
References: <1252@prlhp1.prl.philips.co.uk> <1991Feb20.203009.27357@mozart.amd.com> <6938@ecs.soton.ac.uk>
Date: Wed, 27 Feb 1991 22:28:24 GMT

In article <6938@ecs.soton.ac.uk> gjh@ecs.soton.ac.uk (Gary Hill) writes:
>It is possible to perform compression on the i750 if you also have the
>capture board.  This gives you edit level video.  The info from
>Thorn-EMI who are marketing DVI in the UK say it will do full motion
>video at 10-30 fps.  Thew compression is not as good as the off line
>compression which is called presentation level video, this is because
>elv does not use delta frame compression, but compresses each frame
>separately, as a result, the resolution is not so good for full screen
>video.

That sounds about right.

We just got the new ActionMedia boards in (Capture & Playback) and are
beginning to experiment with capture quality.  It looks like the 30 fps
capture will be usable if you use a smaller playback window (say 1/4
screen), but it is pretty ugly at full screen.  However, our testing
has been limited at this point.

We have also found that with this new 2-board set that if your video
source is anything other than a directly-connected camera, you are
going to need a time-base corrector.

Now a question:  

When you install both the capture and delivery boards, you actually
plug your VGA monitor into the Capture board, and link the VGA board,
Capture board, & Delivery boards together using ribbon cables.  This
works fine if you want the DVI playback to be on the VGA screen (you
can even overlay your DOS text on the DVI images).

But, how are you supposed to connect a standard NTSC screen and use it
for playback of the DVI images?

All you have left is the VGA connector on the Delivery Board and the
VGA connector on your VGA card (which is terminated).



-- 
Andrew Patrick, Ph.D.       Department of Communications, Ottawa, CANADA
andrew@calvin.doc.CA
                    "The interface IS the program."