MMC/Mt Fuji: Clarification about R and RW/Rewritable profiles

[Peter Van Hove]

* From the T10 Reflector (t10 at t10.org), posted by:
* "Peter Van Hove" <Peter at Smart-Projects.net>
*
Dear David, All,
I hope I'm not completely missing the point but
for DVD+R/W the way I understand it is the following.
Suppose a DVD-ROM drive doesn't report any of the DVD+ (plus) profiles (and 
hence also no features), then a modern drive will likely have no issues with 
DVD+R/W discs but will not recognise them as such, only as DVD-ROM discs and 
blank media will likely not be seen as such.
Suppose a DVD-ROM drive that DOES report the DVD+ profiles then indeed a 
host must still request the relevant features to see if that drive is able 
to write also in addition to reading the media.  Since the ROM drive can't 
write, the write bit will be set to zero.
All this means is a "guarantee" that +RW media is properly recognised, 
nothing more.
MMC says:
"This feature may be present only to represent additional capability to the 
DVD-ROM Profile. If the Write bit is
set to zero, then no additional capability is claimed."
I understand "then no additional capability is claimed." as compared to the 
DVD-ROM profile.
The DVD-ROM profile's "interesting" feature is the DVD Read feature.
The DVD read feature does not include the "READ DISC INFORMATION" command.
In other words, a ROM drive that supports the DVD+ profiles and features, 
but doesn't support the write bit to one, does no more than a DVD-ROM drive 
without the DVD+ profiles and features, EXCEPT maybe that it's a guarantee 
that DVD+R/W is supported *EVEN* when the booktype is still the original 
booktype, and not the DVD-ROM booktype that is often used for compatibility.
I could be wrong, but this is how I understand it.
PS., also from MMC (for the DVD+R feature for instance)
"If a Drive reports this feature with the Write bit set to one and the 
Current bit set to one, then it shall support the
commands shown in table ..... "
So only when the write bit is set to one additonal commands are supported, 
including:
the "READ DISC INFORMATION" command
Best Regards,
Peter
-------------------------------------------------------
Peter Van Hove
www.Smart-Projects.net
www.IsoBuster.com
-------------------------------------------------------
-------------------------------------------------------
----- Original Message ----- 
From: "David Burg" <daviburg at windows.microsoft.com>
To: <mtfuji5 at avc-pioneer.com>
Cc: <t10 at t10.org>; "Bhanu Gogineni" <bhanu.gogineni at microsoft.com>; "Ahmed 
Tolba" <ahmed.tolba at microsoft.com>
Sent: Monday, October 16, 2006 8:10 PM
Subject: RE: MMC/Mt Fuji: Clarification about R and RW/Rewritable profiles
>* From the T10 Reflector (t10 at t10.org), posted by:
> * David Burg <daviburg at windows.microsoft.com>
> *
> Hello Katata-san,
>
> Thank you for your answer. Your analysis is correct, in particular for CD 
> and DVD dash where the said profile requests write features to be 
> supported. But remains the particularity of the DVD plus command set, 
> where the profile does not request write features to be supported unless 
> the write bit of the DVD+R/RW feature is one. Still, DVD Read feature is 
> always mandatory, and this one includes the same READ DISC INFORMATION you 
> mention.
>
> Best regards,
>
> David Burg.
>
> -----Original Message-----
> From: owner-mtfuji5 at avc-pioneer.com [mailto:owner-mtfuji5 at avc-pioneer.com] 
> On Behalf Of keiji_katata at post.pioneer.co.jp
> Sent: Sunday, October 15, 2006 11:47 PM
> To: mtfuji5 at avc-pioneer.com
> Cc: t10 at t10.org; Bhanu Gogineni; Ahmed Tolba
> Subject: Re: MMC/Mt Fuji: Clarification about R and RW/Rewritable profiles
>
>
> Hi David,
>
> ----- Question -----
> So the question is: Does reporting R and/or RW/Rewritable profile by a 
> drive
> mandate that it is capable of recognizing the matching blank R and/or
> RW/Rewritable profile?
> -------------------
> I think it is yes. All commands listed in the Features those are listed in 
> the
> Profile shall work correctly. So for example, CD-R profile requests 
> "Incremental
> Streaming Writable Feature" and "CD Track at Once Feature". These Features
> request READ DISC INFORMATION command and READ TRACK INFORMATION command. 
> Those
> information must be reported from any condition of the CD-R disc except 
> fatal
> error condition of the drive. I think Blank condition of CD-R is normal
> condition of the disc.
>
> On the other hand, these Feature request "This Feature identifies a Drive 
> that
> is able to write data". Therefore ROM drive shall not report the 
> supporting of
> there Features. Then ROM drive cannot report CD-R profile.
>
> Best regards,
>
> Keiji Katata
> PIONEER CORP.
>
>
>
>
>
> David Burg <daviburg at windows.microsoft.com>@avc-pioneer.com on 2006/10/14
> 14:05:28
>
> mtfuji5 at avc-pioneer.com$B$KJV?.$7$F$/$@$5$$(B
>
> $BAw?.<T(B:     owner-mtfuji5 at avc-pioneer.com
>
>
>
>
> $B08 at h(B:  <t10 at t10.org>, <mtfuji5 at avc-pioneer.com>
> cc:	 Bhanu Gogineni <bhanu.gogineni at microsoft.com>, Ahmed Tolba
>	<ahmed.tolba at microsoft.com>
> bcc:
> $B7oL>(B:  MMC/Mt Fuji: Clarification about R and RW/Rewritable profiles
>
> Hello,
>
> During validation of DVD-ROM devices conformance to the MMC command set 
> through
> the Windows Vista Logo program and MMCTest tool, we were signaled the 
> possible
> flaw in either our tool or the specification. Our tool query from the 
> drive the
> list of profiles supported by the drive, and then exercises each of the
> profiles. Some ROM drives will also report R and/or RW profiles. Thus our 
> tool
> attempts to validate these profiles, and as part of the validation 
> attempts to
> validate that the drive recognize blank media properly.
>
> Yes, blank media. I understand that hardware manufacturers may very well 
> be
> reluctant to guarantee this capability on ROM drives. The value of 
> recognizing
> blank media in a ROM drive that won$B!G(Bt be able to write it is also 
> questionable.
> However there are also positives aspects: a ROM drive able to recognize 
> the
> blank media will not spin un-definitively in attempt to find a track, it 
> will
> further be capable to report that the media is blank to the host so that 
> the
> host software may report the issue to the user and help him to correct his
> mistake.
>
> Clearly some ROM drives do not support recognizing blank recordable or
> rewritable media, even sometimes do not recognize recorded recordable or
> rewritable media.
>
> So the question is: Does reporting R and/or RW/Rewritable profile by a 
> drive
> mandate that it is capable of recognizing the matching blank R and/or
> RW/Rewritable profile?
>
> Best regards,
>
> David Burg,
> Microsoft Corporation.
>
>
>
>
>
>
>
>
>
>
> *
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