[Question] Read compatibility on DVD-RW DL drive
ai.takaharu at jp.panasonic.com
Mon Feb 26 17:42:34 PST 2007
* From the T10 Reflector (t10 at t10.org), posted by:
* Takaharu Ai <ai.takaharu at jp.panasonic.com>
Hello Mt.Fuji people,
Mt.Fuji group is discussing the command set for DVD-RW DL logical unit
and we need to hear the member's opinion about the read compatibility.
We have decided that the conventional restricted overwrite mode is the
mandatory recording function and the new layer jump restricted overwrite
mode is optional for the DVD-RW DL logical units. So, two types of
products may be shipped in the market. Type1 drive is a drive which
supports only the restricted overwrite mode and Type2 drive is a drive
which supports both recording modes.
The question is whether Type1 drive shall be able to read the
Intermediate state disc recorded in layer jump recording mode or is not
necessary to read.
Currently, two different opinions exist for this situation.
One opinion is that Type1 drive shall be able to read such a disc.
The reason is that an user may write a valuable data in layer jump
recording mode by Type2 drive and may eject the disc without closing the
disc. The user may insert the disc into Type1 drive later. If the drive
does not read the disc, the user cannot recognize such a valuable data
is recorded, and the user may physically format the disc. This is a very
dangerous situation and to avoid this kind of the possible trouble in
the market, Type1 drive shall read the layer jump recorded disc.
Another opinion is that Type1 drive does not need to be able to read
such a disc.
The reason is that typical recording software which uses layer jump
recording mode, does not eject the disc without closing. If the ejected
layer jump recorded disc is always Complete state, Type1 drive does not
need to read Intermediate disc. Since Type1 drive can read the Complete
disc recorded in layer jump recording mode, no trouble will happen.
Both opinions are understandable, and if we can decide the latter
opinion is appropriate, the command set for DVD-RW DL becomes simple and
all the drive manufacturer may be grad. :-)
Could you post your opinion by the next Mt.Fuji meeting?
Thanks in advance.
Panasonic AVC Networks Company
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