Likely editorial error inducing confusion in MMC-4 and MMC-5, DVD+R/RW/DL Profiles

David Burg dburg at
Thu Aug 4 08:21:30 PDT 2005

* From the T10 Reflector (t10 at, posted by:
* "David Burg" <dburg at>
Dear Bill, Dear MMC members,

James Lo from Dell brought to my attention that MMC description of
DVD+R/RW/DL Profiles "contain the requirement to support Read/Write
Streaming which as you know ROM drives cannot support".

I think the DVD+Rxxx Profiles wording induces to a confusion. The DVD-ROM
Profile contains also the Feature 107h (Real-Time Streaming), but a clear
description ("Ability to read using Initiator requested performance
parameters") while the description for the same feature in the DVD+Rxxx
Profiles ("Ability to read and write using Initiator requested performance
parameters") induces the confusion that it looks like a DVD+Rxxx capable ROM
drive would need to support (real-time) writing. I think this is really
un-intentional because you see for write-related features notes such as
"1This feature is mandatory only when the Write bit of the DVD+RW Feature is
set to one."

Reporting DVD+R/RW/DL Profiles as current by ROM drives when matching media
is inserted is desirable to best identify the media. Reporting the Features
even when no media is inserted is required to report the capability of the
device (so for instance diagnostic tools such as Nero InfoTool can provide
accurate information). Actually Profiles and Features go hand-in-hand and
should be present together, shouldn't they?

I propose to change the wording from "Ability to read and write using
Initiator requested performance parameters" to "Ability to read and
optionally write2 using Initiator requested performance parameters", with a
note "2 Real-Time Streaming Write is supported when the Write bit of the
DVD+Rxxx Feature is set to one."

Btw, is there any ISV which assimilated erroneously the presence of
DVD+R/RW/DL Profiles to the capability to write these media due to the above
reported confusion? (Nero products do not, but we wonder about other ISVs.)

Best regards,

David Burg

David Burg
Software Development

Nero AG               phone: +49 (0)7248 928 327 (room line) Internal VoIP
Im Stoeckmaedle 18    fax:   +49 (0)7248 928 299
76307 Karlsbad        email: dburg at

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