Twin Format layer to play selection issue for PC software player

David Burg dburg at nero.com
Fri Aug 12 02:58:10 PDT 2005


* From the T10 Reflector (t10 at t10.org), posted by:
* "David Burg" <dburg at nero.com>
*
Hello Katata-san,

Questions are always welcome! :-)

4. " So the file system on the last session has file system information of
all files in all sessions."

I think the idea is precisely *not* to reference the previous session in
this multi-format multi-session. The second session does not reference the
files of the first session. If you want to access the files of the first
session, you will have to 'unmount' the second session and mount the first
session. Or more easily, if the file system driver mount the second session,
the playback software once it finds out it needs to access the first session
content (either to play the CD audio sound track or because it does not have
suitable codecs for the second session) parse the file system itself through
block access

.5. Assumed demerit of this scenario is that when HD playback software is
crashed, OS file system cannot recover data reading from the DVD layer.

Sorry, I could not understand your problem scenario / could not match with
this today's playback-OS file system functionalities.

Best regards,

David Burg,
Nero AG.

-----Original Message-----
From: owner-mtfuji5 at avc-pioneer.com [mailto:owner-mtfuji5 at avc-pioneer.com]
On Behalf Of keiji_katata at post.pioneer.co.jp
Sent: Friday, August 12, 2005 3:34 AM
To: mtfuji5 at avc-pioneer.com
Cc: t10 at t10.org
Subject: RE: Twin Format layer to play selection issue for PC software
player


Hi David,

May I ask questions?

3. Regarding the autoplay disc content scanning

I may misunderstand this. So the file system on the last session has file
system information of all files in all sessions. Explorer shows ICONs of
files. Where is the ICON data of EXE file stored? Where is the allocation
information stored?
If same file name are used in 1st session and in 2nd session, what happens?


5. "Anyway UDF

If a PC system that does not have UDF 2.5/2.6, the PC manufacturer may
select DVD-ROM format layer as the default mount layer. Then user can see
the files in the disc. After such HD playback software runs, HD layer is
mounted, then HD contents will be played back.
Assumed demerit of this scenario is that when HD playback software is
crashed, OS file system cannot recover data reading from the DVD layer.

Assumed demerit of the multi-session scenario is that the hybrid disc is
not visible on such PC system. Then how the autorun works?

Best regards,

Keiji Katata
PIONEER CORP.





"David Burg" <dburg at nero.com>@avc-pioneer.com on 2005/08/12 01:33:45

mtfuji5 at avc-pioneer.com$B$KJV?.$7$F$/$@$5$$(J

$BAw?.<T(J:     owner-mtfuji5 at avc-pioneer.com




$B08 at h(J:  <mtfuji5 at avc-pioneer.com>
cc:    <t10 at t10.org>
bcc:
$B7oL>(J:  RE: Twin Format layer to play selection issue for PC software player

Hello Katata-san,

I have as well not decided anything yet, but I'll jump in regarding the
file
system. ;-)

3. Regarding the autoplay disc content scanning at insertion, this is done
|from a user mode component doing regular file system access. Henry
mentioned
in a later e-mail he propose to minimize the reference from high definition
layer to low definition layer. Accordingly, assuming that the file system
will mount the highest session like Windows does today, the content
scanning
will generate only if not mostly access to a single layer.

5. "Anyway UDF
2.5/2.6 is necessary for Blue media. So we may not need to talk about such
old OS. Because the system cannot mount the disc."

Sorry this is not correct for Video disc. Video playback software are used
to perform block access and parse the filesystem themselves. Hence they are
not bind to the OS for the reading of the file system. For instance, Nero
ShowTime is able to read Temp_VMGI video discs although the OS does not
understand its file system. The same is likely to apply to UDF 2.50/2.60.

Best regards,

David Burg,
Nero AG
.





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