Subject: Error in free block computation in mmc5r03a
Date: Wed, 26 Jul 2006 13:06:19 -0700
From: "David Burg" <daviburg@windows.microsoft.com>
To: <t10@t10.org>
X-Message-Number: 7099
Formatted message: HTML-formatted message

Hello,
A technical error (or at least an inconsistency) was introduced in the
read track information description of free block by partially removing
DDCD text.
The text in mmc3 was:
"For CD media, this field shall be computed as follows: First, the
Available Track Space (ATS)
shall be computed.
For the invisible track, ATS = (StartTimeofLastPossibleLead-out) - NWA +
5.
For a reserved track, ATS = (PMAStopTime) - NWA + 5.
[empty line separating 2 paragraphs]
For DDCD media, this field shall be computed as follows: First, the
Available Track Space (ATS) shall be
computed.
For the invisible/incomplete track, ATS =
(StartTimeofLastPossibleLead-out) - NWA + 4.
For a reserved track, ATS = (PMAStopTime) - NWA + 4.
[empty line separating 2 paragraphs]
"
The MMC5 text is currently:
"6.26.3.15.1 CD
For CD media, this field shall be computed as follows: First, the
Available Track Space (ATS) shall be
computed. In the cases that follow StartTimeofLastPossibleLead-out is as
defined in 6.22.3.1.17.
For the invisible track, ATS = (StartTimeofLastPossibleLead-out) - NWA +
5.
For a reserved track, ATS = (PMAStopTime) - NWA + 5.
For the invisible/incomplete track, ATS =
(StartTimeofLastPossibleLead-out) - NWA + 4.
For a reserved track, ATS = (PMAStopTime) - NWA + 4.
"
So these two lines:
"For the invisible/incomplete track, ATS =
(StartTimeofLastPossibleLead-out) - NWA + 4.
For a reserved track, ATS = (PMAStopTime) - NWA + 4.
"
Are confusing left-over from DDCD that shall be removed. Otherwise CD
computations could be wrong or one block (I just saw a wrong code,
discussed with the author of the code who pointed me to the error in the
spec, which he could not know was an error).
Best regards,
David Burg
Research Software Engineering Lead
Tel.: +1 425 707 8769