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

David Burg dburg at nero.com
Wed Mar 3 11:07:46 PST 2004

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

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

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