#Multi-Volume CD's?
8 messages in this thread
Has anyone ever heard of Multi volume CD's where there are several
different data areas on one CD? I know about Kodak Multi-session CD's but I
had someone who said this was a different standard. Any input would be
appreciated.
Thank you
Kelly:
There are products that have distinct "databases" or "data areas," often
for the purpose of combining multiple info products on the same disc.
Usually the customer is charged for each "key" to unlock each section. The
most common of these products are type libraries from companies like Adobe,
Agfa, Linotype, Etc.
There are also a few products that have multiple databases on a disc
because the databases are different structures, or cover different types of
info. Usually these are "covered" by an umbrella menu that enables the
customer to move from source to source without leaving the application.
I'm not remembering many names in this category, but one that pops up is a
high-end product called OneSource from Lotus that delivers a variety of
financial news, stock quotes, and investment analysis data source from a
single app.
Hope this helps!
Rich Bowers
Rich,
What about the lower level than that? Like at the ISO-9660 filesystem
level. If you have a primary volume descriptor that gives that start of a
specific volume you could have another volume descriptor that defines
another volume. Is this what they are talking about with regards to
multi-volume on one disc?
Albert:
No, I don't think that's what I'm talking about. I think I'm referring
more to the situation where there is more than one file (in technical
terms) tied together with a s/w interface.
Rich
Thats great information Rich, thanks for taking the time to explain that. I
gather that you have not really heard of these being referred to as
"Multi-Volume" but the description seems to fit.
Thanks again,
Kelly
I have heard multi volume used in the context of appending information to a
CD at different times. The retrieval software and/or CDROM driver would
have to be aware that there may be two or more ToC's on the disk. My
CD-ROM recorder, a Sony CDW-900E, is a single session machine and so once I
write to a disk I can not write to it again. There are CD recorders that
can append information to a disk (I think JVC offers one) but I understand
that most drivers do not support this yet.
The Philips CD-WO specification uses the terms "volume" and "multivolume"
to mean the same thing that the Kodak PhotoCD and the Bridge disc spec.
call "session" and "multisession". ISO 9660 uses the term "volume" to mean
a physical CD-ROM, and "multivolume" to mean a directory heirarchy that
spans more than one physical disc. \/exit
Hi Matt,
as I think I haven't explained it correctly to Kelly Fraser, here is a new
try:
Let's assume two "multi-session" CD-ROMs: the Kodak Photo-CD and the one
written on a CDD521 with a normal ISO-Formatter like Philips' CDWRITE or
WIN-On-CD (which I'd like to call "multi-partition" as I found out that
"multi-volume" is alredy used for something different). Both are written on
the same machines (PCD-200 = CDD521).
Kodak:
First session is ISO9660. If a session is appended the directory is written
for ALL previous sessions. This makes the CD-ROM look like one big CD. As
the naming convention for the PCD-Files is IMAGE.xxx (where xxx is a
number) there are only unique filenames! Trying to read a multi-session
Photo-CD on a single-session drive you'll see probably only 5 images while
the multi-session drive shows more. The drive must only search the last
session and gets the latest directory for all sessions. This speeds up the
access but you can't use identical filenames in several sessions. This is
not important for the imgaes right now, but how if there'll be the
possibility to add sound and data and…
PHILIPS:
First session is ISO9660. The next session is written as a CD-WO (Orange
Book Part II). The directory contains only the files in this session.
That's why you can write a couple of adjacent sessions containing exactly
the same files with the same filenames!!! A session on the CDD521 has to
be selected by a program and the session appears as it would be a sole
CD-ROM. It's a kind of "window" within the whole CD-ROM.
As both formats differ in how they handle the file structure of additional
sessions the question is:
Does KODAK's format or PHILIPS' format comply to Orange Book Part II ?
Any ideas ?
I hope this time it's understandable <G>.
Bye, Torsten