Re: CD titles with Mosaic

Chris Lilley, Computer Graphics Unit (
Thu, 7 Jul 1994 16:06:52 GMT

In message <> Murali (

> I'm helping develop a Mosaic home page for a Science Center/Museum

By this I presume you mean one of two things:

a) You are writing Web pages which are targeted to a particular browser, and
which you envisage will only be used with that browser

b) You are writing web pages, and have used Mosaic as a synonym for the Web.

If the former, you can only force people to use one browser with the CD version,
assuming you supply the browser too. Your assumption is invalid if you make the
Internet version available on a Web server.

If the latter, you should be aware that there are other browsers besides mosaic,
and other software components to the Web besides browsers.

>The Center wants to make this available to local schools on a CD-Rom also,
>specifically those that do not have access to the internet. Since some
>schools have PC's and some have Mac's, I want to store pictures/graphics
>and video clips in a format that can be viewed on these platforms.

Eminently sensible. In addition, for the Internet version you would be well
advised to use formats that can be viewed on Unix platforms too.

So, you want platform independent file formats. Those in general use that can be
viewed on Mac, PC/WinDoze and Unix/X platforms include (common usage in

Still Images

two colour images (foreground / background) Can be used inline
older PC versions of Mosaic did not handle these. Later ones do.
Check that Macs handle these, I am told they do but have no Mac
to check

general 8 bit images. Can be used inline.

8 bit images with transparency. Can be used inline.

baseline TIFF v6
24 bit images where no degredation is acceptable
note that baseline TIFF 6 excludes LZW compression due to patent
scares, though it was part of the "baseline" TIFF 5 spec.

24 bit images where some degredation is acceptable


Widely available. If you require fast frame rates (ie 25/30 frames a
second) PC and Mac require hardware assisted decoders. Some free PC
viewers, eg the Xing one, are broken.
Payware players available on PC, free players on Mac, shareware players
on Unix/X. Not all codecs can be used - check the xanim manual for
details. You must flatten the movies into the data fork.

Examples of non-platform portable formats include PCX and BMP (PC/WinDoze and
Unix/X only); PICT (Mac and Unix/X only); unflattened Quicktime movies, SGI
movies, etc.

>1. Is it possible to author a CD with Mosaic?

No. Mosaic is a viewer and has no editing capability.

However it is possible to create a Web on a CD, and use a web browser such as
Mosaic to view the CD. Either directly (using file://localhost URLS) or with a
server running on the PC with the CD drive.

>2. If so can anyone recommend formats to store these files such that
> I dont have to worry about maintaining separate formats for
> separate platforms:

See above

>3. Common viewers for these formats (xv, mpeg_play etc) and platforms.
> I dont want to maintain different viewers for PCs and Macs.

You will need to have separate viewers for PCs and Macs as they are not binary
compatible. That should not be a problem, though.

Luck with your project,

Chris Lilley
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