Jan-Eric Duden jdu at
Fri Sep 24 04:24:37 PDT 2004

* From the T10 Reflector (t10 at, posted by:
* Jan-Eric Duden <jdu at>

I have a question regarding the specifications of the GET PERFORMANCE 
and READ CAPACITY commands (MMC4r03b).
If write speed descriptors (type 3h) are requested through the GET 
PERFORMANCE command the specification states in :

"The End LBA field shall indicate the medium capacity if a medium is 
mounted. The value shall be
same as the value reported by READ CAPACITY command. If no medium is 
mounted, the Logical
Unit shall report the maximum capacity of the most appropriate media. "

The READ CAPACITY specification states in 6.23.1 :
"This capacity is reported with respect to reading operations." and in 
table 357
"DVD, non MRW-format: The last addressable user data block (= Last 
Recorded Address) in the last track of
the last complete session"

This means that the End LBA in both cases is the Last Recorded Address, 
which is not necessarily the medium capacity.
Setting the End LBA field of a write speed descriptor to the Last 
Recorded Address doesn't seem to be correct.
Am I missing something?

MfG / Regards
Jan-Eric Duden
ashampoo Technology GmbH & Co. KG

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