DVD+MRW support report issue

David Burg dburg at nero.com
Mon Oct 24 06:49:15 PDT 2005

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

I apologize for reporting a problem so near from MMC-5 completion but...

One pain with MRW feature is that it does not tell whether its support is
for CD+RW only or also for DVD+RW. My guess is that the engineers who
designed it originally wanted to give an abstraction layer where the host
software wouldn't have to care about the disc anymore once the MRW was
there. Unfortunately, the market reality is that many if not all MRW capable
DVD recorders actually support MRW only on CD. But the command set can't
report that to the host, except with evil tricks such as hiding the MRW
feature when a DVD+RW disc is inserted. Hence, Nero would like to propose to
add a 'DVD+RW' bit to the feature descriptor to indicate whether DVD+RW are
supported or not. This is required for us both to properly report DVD+MRW
capability in diagnostic tools such as Nero InfoTool, but also to offer
proper format option in our packet writing solution InCD.

Question: Does someone has released devices capable to read DVD+MRW,
read/write CD-MRW but not write DVD+MRW? If so, we would even need to split
in 3 bits, CD-MRW write (current write bit), DVD+MRW read, DVD+MRW write.

Btw, is it right to report 0h as version for MRW feature for coming MMC-5? I
thought corrections to the MRW physical format had being done - shouldn't
device report new revision to claim compliance with new physical format
specification? :-?

Best regards,

David Burg

David Burg
Senior Engineer
Standardization and Research

Nero AG               phone: +49 (0)7248 928 327
Im Stoeckmaedle 18    fax:   +49 (0)7248 928 299
76307 Karlsbad        email: dburg at nero.com
Germany               http://www.nero.com

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