FP and Packet/Inc bits for DVD+RW in MMC-4 draft

Bill McFerrin billmc at tstar.net
Thu Mar 4 09:01:02 PST 2004


* From the T10 Reflector (t10 at t10.org), posted by:
* "Bill McFerrin" <billmc at tstar.net>
*
Mr Burg,
The DVD+RW Profile contains no Feature that requires support of the READ
TRACK INFORMATION command.  For this reason, MMC-3 did not address DVD+RW.
One of the goals for MMC-4 was to improve all descriptions and also be as
complete as possible.  With respect to this goal, we have included
descriptions for optional behaviour where we believed it to be important.

We have defined the values in the Track Information Block according to the
unique characteristics of DVD+RW.  This was done in consultation with the
original manufacturers of DVD+RW devices.  During our meetings, we often
have 2 software companies present for additional consultation.  Given all
this, we still fail to have an industry-wide consensus when we look at
acceptance through implementations.

For MMC-4 compliance, you should look at the description of the INQUIRY
command in MMC-4.  The version descriptors should be included.
Unfortunately, inclusion of version descriptors is...optional.

Regards,
Bill McFerrin

-----Original Message-----
From: owner-t10 at t10.org [mailto:owner-t10 at t10.org]On Behalf Of David
Burg
Sent: Wednesday, 03 March, 2004 1:08 PM
To: t10 at t10.org
Subject: FP and Packet/Inc bits for DVD+RW in MMC-4 draft


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

As this is my first contribution to t10 reflector, I might be asking
something that has already been asked. Although, I was not able to find an
answer in the reflector e-mail archive.

My question is about Read Track Information command (op code 52h) response,
and more precisely for the Track Status, RT and Packet/Inc bits, for DVD+RW.

In MMC-3, values were not defined for DVD+RW media. In MMC-4 they are
defined as Packet/Inc = 1 always (Table 468 of r02h draft) and FP (Fixed
Packet) = 1 always (Table 469).

Unfortunately multiple DVD+RW devices were released on the market before
MMC-4 draft were available. 6 out of 8 brands of DVD+RW device I tested
reports Packet/Inc and FP bits as 0 for DVD+RW media. My impression is that
it will not be possible for a software to use the value these bits on a
DVD+RW media without either breaking MMC-4 specification or breaking support
of existing devices.

Is it possible for a software to check if the device conforms to MMC-4
specification, thus that Packet/Inc and FP bits can be expected to 1 for
DVD+RW media?

Best regards,

David Burg

----------------------------------------------------------------
David Burg
Software Development,
InCD Project Leader

Ahead Software AG     phone: +49 (0)7248 911 862 (direct line)
Im Stoeckmaedle 18    fax:   +49 (0)7248 911 888
76307 Karlsbad        email: dburg at nero.com
Germany               http://www.nero.com
----------------------------------------------------------------

*
* For T10 Reflector information, send a message with
* 'info t10' (no quotes) in the message body to majordomo at t10.org



*
* For T10 Reflector information, send a message with
* 'info t10' (no quotes) in the message body to majordomo at t10.org




More information about the T10 mailing list