Twin Format and Hybrid Disc proposals

David Burg dburg at
Wed Aug 17 08:18:36 PDT 2005

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

Nero had an internal study of the Toshiba, MEI and Microsoft proposals for
Twin Format and Hybrid Disc.

We currently favor the proposals from Toshiba and MEI because we see the
following concerns with the Microsoft proposal:

- What information to return to Read Disc Information? If RDI returns one
session per format layer, then it is not possible to have multiple sessions
per format layer (for instance, CD and DVD have physical multi-session
- What current profile to report, DVD, CD, HD-DVD, BD, something new? How to
report the features specific to a format layer?
- How to interpret disc-wide commands such as close disc?
- Send/Report Key: the commands are disc-wide and do not include a format
layer field to tell the logical unit to which layer the command applies.

We are however concern by the layer selection by playback software issue
raised earlier for Toshiba and MEI proposals.

Regarding the media change issue on change of format layer we believe that
the content provider could resolve this by creation an autorun.exe on each
format layer which will stop the autoplay if a host software initiating the
format layer change is present.

Regarding the default layer selected at insertion, we think it has to be the
higher definition layer (BD or HD-DVD, not DVD or CD).

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

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