#Multisession ?
23 messages in this thread
Can anybody tell me what multisession means ?
Joe:
Every CDROM is at least single session: that is, the data is recorded, and the
appropriate entries are made in the table-of-contents of the disc to show where
are the data is.
Some CDROMs are now recorded one at a time – notably Kodak's Photo-CD and the
so-called CD-Recordable discs. These discs can have more than one "session"
recorded on them as data is recorded at different times. Thus the need for
"multi-session" drives.
The capabilityto read multisession is part of the firmware of the drive, so old
drives must be upgraded, or new drives must carry this capability as a feature
(increasing numbers do).
A more complete explanation can be found in the CDFAQ.TXT file in Lib #1 if you
need more info.
Best – Rich
Can I jump in here? Last time I checked, there was an international standard
waitin to be approved for appendable (multisession) or Orange Book media. It
was proposed by the Frankfurt Group, and is the equivalent of the High Sierra
Standard that was later approved by ISO as ISO 9660. Also, lat time I checked,
this standard was to include suport for all character sets in the world, UNIX,
and was expandable for future file systems. Am I so out of it that nobody told
me about this standard being abandoned? Is Photo CD now the de facto standard,
or might the new ISO standard make Photo CD as useful as a Beta VCR?
Dana (not Bob, I'm using his account)
They generally refer to it as Kodak Multisession, if that helps, and, yes,
it's a different "standard." But right now it's the only game in town for the
Kodak CD photo format and is likely to be the one used by others when they come
along because it's in the firmware of the Phillips CD recorders and is also in
the code hard-coded into the XA chips in the "Kodak multisession" CD ROMs.
It's one thing to proclaim a standard; it's another to make it THE
standard. Also, remember, standards really do well on the PC side if they
remain standards for more than 6 months. We've gone from proprietary SCSI to
SCSI-1 to SCSI-2 to FastSCSI-2 and soon SCSI-3.
I believe that Kodak's system is popular because it doesn't care if it's in
a Mac or PC–if the software is Kodak compatible and the CD ROM is as well, it
works, period. One recorder, one file structure. That's a standard. Maybe not
THE standard, but it's the one Photo CD is using and it's catching on rather
quickly. A number of graphics programs, in fact, now accept the Kodak Photo CD
as a legitimate import/export object, too.
Jack,
>> ….. hard-coded into the XA chips in the "Kodak multisession" CD ROMs.
Kodak doesn't make or sell CD-ROM drives. Are you refering to our home Photo
CD players, that play Photo CD discs to TV and audio CDs to stereo systems?
>> They generally refer to it as Kodak Multisession …
I'm not sure who "they" are, but we (Kodak) refer to it as CD-ROM XA Mode 2,
Form 1, multisession. So do the computer and software companies that we talk
to.
>> It's one thing to proclaim a standard; it's another to make it THE standard.
Not sure we did either.
We asked Philips and Sony to modify the CD-ROM XA standard to include
multisession.
>> I believe that Kodak's system is popular because it doesn't care if it's in
a Mac or PC …
Agree. To that I would add "… or a UNIX system, or a Photo CD or CD-I, or
Atari, Acorn, or 3DO player."
>> A number of graphics programs, in fact, now accept the Kodak Photo CD as a
legitimate import/export object, too.
This is true for import, but not yet for export (we are working on that side
right now).
On the import side, we have encouraged this by offering Photo CD Software
Developer Toolkits for DOS, Windows, Mac, and UNIX systems, and holding
discussions with other operating system developers, such as Apple, Atari, and
Acorn, who all have ported Photo CD compatibility to their own systems.
Regards … Paul
You'll agree that multisession XA is really best in firmware; current MPC
CD ROM drives now include support for it within their chip set, and a few offer
firmware upgrades from single-session to multisession capability. However, I
don't know of any way to play and use multisession XA disks using strictly
software. Do you? Since that's what I said, what's the quibble?
Jack,
>> You'll agree that multisession XA is really best in firmware …
Yes.
>> However, I don't know of any way to play and use multisession XA disks using
strictly software.
I don't think so. Joel White, in our technical service area (71333,727) might
have a more definite answer to this.
Regards … Paul
Dana:
Frankfurt is still alive, but struggling to stay viable. There are some
corporate forces within the group who apparently have vested interests in
keeping the situation in some chaos for a while – the company, which I suppose
must remain nameless – has become one of the most cynical, insidious forces in
our business, and seem dedicated to halting all progress until they can figure
out how to recoup the dollars lost on other misadventures.
It's my further understanding that there is nothing in the Photo-CD approach
that is fatal to Frankfurt. On the contrary, Kodak has tried to stay in that
mainstream, doing only what was necessary to get their product on the market.
In my view, there remain two major problems to resolve. One involves the
inter-session gap which is apparently on the order of 30MB currently. The
other is that each session currently appears as a separate partition, so it is
difficult to move smoothly from data in session 1 to data in session 2.
The resolution of these issues for non Photo-CD applications (eg., corporate
archiving in CD-R) is critical, but first the group must get free of its own
mini-hostage crisis.
Best – Rich Bowers
Thanks for the clarification, I think I can guess who the hold-out is. It's
nice to hear an objective opinion from someone who isn't frothing at the mouth
over Photo CD. I personally have serious misgivings about a "proprietary
standard", which is an oxymoron of the most moronic order. I would like to go
on the record to report, as the owner of a CD-I, that Photo CD will display on
that platform, but is severely crippled. My bias against Photo CD is shared, by
the way, by many Photo CD developers, who have gripes about the closed
architecture. (I learned this in the course of research for THE BOOK)
Dana
Dana:
I have no quarrel whatsoever with what Kodak has done with Photo-CD, in fact I
think they have probably achieved the best of both worlds in creating a
standard for storage and presentation that meets critical technical
requirements (and builds a business for themselves), while at the same time
spreading the word and the technology among all the major players who can make
it accessible. I would venture to guess (out of the bliss of pure ignorance, I
hasten to point out!) that if you are having a problem with Photo-CD on your
CD-I, it ain't the disc that's the problem. The corporate culprit I referred
to earlier does not begin with a "K."
Best – Rich
I gathered that. Still, should Kodak claim that Photo CD works on CD-I when in
fact it works marginally, at best?
The heretofore unmentioned company (and by now we all know who it is) is, after
all, the one that Kodak chose to help it gain entry to the compact disc
technology. From their side (and remember, I don't work for them, it's just
that they've been very helpful and forthcoming with me in the course of my
research) wouldn't it be in all of our best interests to advance the WHOLE of
compact disc standards and technology?
Dana
Bob,
>> Still, should Kodak claim that Photo CD works on CD-I when in fact it works
marginally, at best?
Philips owns the software (and its development) that makes a Photo CD disc play
on a CD-I player.
Shouldn't you address this question to Philips?
Regards … Paul
Well, I got my CD-I player, whish stanadard was announced in 1987 or
therabouts, BEFORE Photo CD came out. Seems to me, if they wanted to that they
were compatible, they (Kodak) would have made more of an effort to be
compatible with the hardware and software that existed. I know that Kodak and
Philips are having a tiff (not the graphics format) over this. It's likely that
Kodak will boot Philips, who helped them gain entry to this market, as soon as
they can.
Dana
Dana:
>>I got my CD-I player, whish stanadard was announced in 1987 or therabouts,
BEFORE Photo CD came out.<<
Not to be overly picky, but when the CD-I format (_not_ standard, but
proprietary format) was intro'd in 1986, I don't think anyone expected it would
take over 5 years for a product to be for sale. Just like everyone else, if
Kodak was looking for CD-I compatibility, they were shooting at a moving
target. The rest of the world moved on while Philips tried to make their old
technology work. Seems to me it's their responsibility to see their players
work as advertised.
Best – Rich
Rich,
>> The rest of the world moved on while Philips tried to make their old
technology work. Seems to me it's their responsibility to see their players
work as advertised.
Thank you for bringing some sanity to this conversation.
Regards … Paul
Bob,
>> It's likely that Kodak will boot Philips, who helped them gain entry to
this market, as soon as they can.
No, it is not. Philips and Kodak share much of the technology and the patents
are intermingled.
However, each member of the team has responsibilities. Phililps decided to use
software to display Photo CD images, and they design that software. Kodak
decided to use an ASIC.
When people ask what to buy, a Philips CD-I player or a Photo CD player, my
answer always has been to decide what is more important.
If the increased multimedia functionality of a CD-I player is more important,
then the CD-I player if the choice, but Photo CD capability will suffer.
If Photo CD is more important, and the absence of motion and FMV (which the
CD-I player have) is acceptable, then the Photo CD player is the best choice.
I am sorry that you are not happy with the CD-I player's playback of Photo CD
images. Still, Philips can adjust the software to make it work better. They
have upgraded it once that I know of, since the first introduction of Photo CD,
and they can upgrade it again.
It still would be wisest to deliver your message to Philips, to encourage them
to upgrade their software. Philips is active in the Multimedia forum, where
there is a CD-I section. Andy Davidson is one of the Philips employees.
Perhaps you should contact him. Andy has always been very helpful and friendly
to me. I am sure he will accept your suggestions gracefully.
Regards … Paul
Bob,
>> I would like to go on the record to report, as the owner of a CD-I, that
Photo CD will display on that platform, but is severely crippled.
Unfortunately, Philips chooses to display Photo CD images using software,
instead of the ASIC used in Photo CD players. The software is less efficient,
but Philips does upgrade it to try to improve performance.
>> "proprietary standard"
Since we license Photo CD compatibility, either from the toolkit, or directly
to operating system developers (Apple, Atari, and Acorn so far), I am not sure
what you mean. Could you explain please?
Regards … Paul
Funny–I got the impression that Kodak's Photo CD was introduced so that
Kodak could sell it as a service and make a lot of money. I doubt with their
patents and copyrights that they would be too thrilled to see competing photo
companies offering it without paying royalties. Kodak is, after all, a
photography company, not a software or computer hardware company, so computer
stuff is just another product.
On the other hand, I've been around computers long enough to wonder just
how long it'll take entrepeneurs to legally clone it.
Jack,
>> Funny–I got the impression that Kodak's Photo CD was introduced so that
Kodak could sell it as a service and make a lot of money. I doubt with their
patents and copyrights that they would be too thrilled to see competing photo
companies offering it without paying royalties. <<
The cost to an ISV to include Photo CD read and discplay capability in their
software is $695 for the Kodak Photo CD Software Developer Toolkit. That is
it.
The ISV owns the application it created, and can sell it or give it away. No
more money is involved. So when Adobe put Photo CD directly into the "File
Open" menu, their payment to Kodak was $695 once and for all.
Photo CD Software Developer Toolkits are available for Mac, Windows, DOS, and
Sun UNIX. For other operating systems, we work with the developer to port the
toolkit. This already has happened for Atari and Acorn, and will be happening
for several other platforms.
On Macs, QuickTime 1.5 reads Photo CD images directly. No other software is
required to open the image. Our strategy is to get all other major operating
systems to include direct access to Photo CD images at least as well as Apple
did with QuickTime 1.5.
When we introduce Photo CD Portfolio authoring software this summer, we will
make an API available FOR FREE to ISVs who want to introduce Photo CD Portfolio
scripting into their applications, letting them *output* to fully compatible
Photo CD Portfolio discs (with full image packs, in all resolutions).
Photo CD Portfolio authoring software includes a feature called "image packer"
that lets the user convert TIFF files (later PICT and other files) to fully
compatible Photo CD format.
This means that any digital still image can be written to Photo CD, including
digital cameras, output from image editing programs, and presentation or
multimedia programs. This software will be available for Sun, Mac, and Windows
initially.
Regards … Paul
You miss my point. If you could make a camera that would only accept Kodak
film you could almost afford to give away the camera, and, in any case, it
would be a one-time charge. On the other hand, Kodak processing companies who
do Photo CD charge for the service using Kodak systems the same way they might
use Kodak developer and paper and so on. You are talking hardware and software;
I am talking product.
Jack,
>> Kodak processing companies who do Photo CD …
In the U.S., there are no "Kodak" processing companies. Photo CD transfers are
done by independent photo labs or service bureaus who purchased Photo CD
Imaging Workstations.
By this summer, even the Photo CD Imaging Workstation won't be necessary, as it
will be possible to create Photo CD discs using an out-of-the-box Sun Sparc
Station. This will be true with Macs by this fall, and Windows systems by
early next year.
Since Fuji and Konica have licensed the technology, at some point they also can
be expected to sell workstations to transfer images to Photo CD discs.
Anyone can make Photo CD compatible software with a very low investment ($695).
Anyone with a license, such as Fuji or Konica, can make Photo CD Imaging
Workstations (or even Photo CD discs).
Beyond that, you are right. I don't get your point.
Regards … Paul
Bob,
>> … or might the new ISO standard make Photo CD as useful as a Beta VCR?
The new ISO standard will include Photo CD capability (which is actually ISO
9660 with multisession added) as a subset. It will actually make Photo CD even
a stronger cross platform format.
Regards … Paul
Bob,
>> Is Photo CD now the de facto standard …
No.
Photo CD will be included in the Orange Book standard.
Regards … Paul