Determining the certified write speeds of DVD-R/-RW discs byinterpreting pre-recorded lead-in information.

keiji_katata at post.pioneer.co.jp keiji_katata at post.pioneer.co.jp
Tue Oct 14 23:31:34 PDT 2003


* From the T10 Reflector (t10 at t10.org), posted by:
* keiji_katata at post.pioneer.co.jp
*

Kris, you should refer to DVD-R book. Or you can check Mt.Fuji5 Rev 1.5
page 134 table Table 44 - Copy of Pre-recorded Information.

About Pioneer DVD-R 2X writing speed, it is vender unique function. Like
CD-R, some Pioneer writers support 2X writing on some 1X DVD-R disc. It is
not true for all drives and all DVD-R discs.

Best regards,

Keiji Katata
PIONEER CORP.





Kris.Schoofs at pimc.be@t10.org on 2003/10/14 18:35:05

$BAw?.<T(J:     owner-t10 at t10.org




$B08 at h(J:  t10 at t10.org
cc:
bcc:
$B7oL>(J:  Determining the certified write speeds of DVD-R/-RW discs by
       interpreting pre-recorded lead-in information.

* From the T10 Reflector (t10 at t10.org), posted by:
* Kris.Schoofs at pimc.be
*
I am attempting to determine the certified write speeds of DVD-R/-RW media
by interpreting the pre-recorded information in the lead-in (by using READ
DVD STRUCTURE : Format code 0x0Eh (Pre-recorded information in Lead-in)).
My goal is that even on older writers it will be possible to identify all
of the disc's certified write speeds (albeit they will be unable to write
the higher speed discs).

I've already done this successfully for DVD+R/+RW (by interpreting the
ADIP) but I'm struggling with DVD-R/-RW.

My current approach is counting the FIELD IDs in the 'pre-recorded
information of the lead-in'-structure (as returned by READ DVD STRUCTURE).

So :
Field ID=5 present (located at offset 32, excluding the
ReadDVDStructure-header)
=> only 1X write supported by the disc

Field ID=7 present
=> also 2X write supported by the disc

Field ID=9 present
=> also 4X write supported by the disc

Field ID=11 present
=> also 6X write supported by the disc

Field ID=13 present
=> also 8X write supported by the disc


But after analysing a few discs I noticed that this approach doesn't work.
Example#1 :
=> A Pioneer DVD-R labeled as 2x disc only reports up to FieldID=5 (the
same as a 1x disc does)
Example#2 :
=> A Pioneer DVD-R labeled as 4x disc reports up to FieldID=13. Which,
according to my (obviously wrong) assumptions would lead to the concluision
that this disc also supports 8X write (which it clearly doesn't).

Is it at all possible to establish a disc's certified write speeds by
interpreting returndata from MMC commands ?

If so, can somebody help me out by clarifying which fields need to be
examined in order to obtain the information I need.

Thanks,

Kris


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