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

[David Burg]

* From the T10 Reflector (t10 at t10.org), posted by:
* David Burg <daviburg at windows.microsoft.com>
*
Dear Peter, All,
I am reading mmc5r03c.pdf. This is the latest MMC 5 document on www.t10.org
Thank you Peter for the clarification. However something does not add up:
there is a delta between the DVD-ROM profile mandatory features and the
DVD+RW profile mandatory features, not only write features (20h and 23h), and
DVD+RW feature (2Ah), but also DCBs (10Ah). This is more than DVD-ROM
capabilities so I question that the spec sentence "If the Write bit is set to
zero, then no additional capability is claimed." really means not additional
capability but DVD-ROM read is claimed. I think it means instead, no
additional capability than claim until here in this feature definition.
Likely referring to the feature introduction "The presence of the DVD+RW
Feature indicates that the Drive is capable of reading a recorded DVD+RW disc
that is formatted according to [DVD+Ref2]."
Now we could approach the problem differently than splitting hairs and trying
to second-guess the meaning of the sentences, and try instead to specify what
is the actual drives on market behavior. You say that most ROM drives won't
see blank and +R/RW features and profiles don't change that. Maybe we need a
clarification sentence in the specification of the +R/RW features, rewording
the introductions sentences:
"The presence of the DVD+RW Feature indicates that the Drive is capable of
reading a recorded DVD+RW disc that is formatted according to [DVD+Ref2].
Recognition of blank DVD+RW disc is guaranteed only if the write bit of this
feature is set to one."
Btw, there is an inconsistency between the RW and the R feature specification
wording. Only the R feature says "Specifically, this includes the capability
of reading DCBs."
Best regards,
David Burg,
Microsoft.
-----Original Message-----
From: owner-mtfuji5 at avc-pioneer.com [mailto:owner-mtfuji5 at avc-pioneer.com] On
Behalf Of Peter Van Hove
Sent: Tuesday, October 17, 2006 2:19 PM
To: mtfuji5 at avc-pioneer.com; t10 at t10.org
Subject: Re: MMC/Mt Fuji: Clarification about R and RW/Rewritable profiles
Dear David, All,
> If I correctly understand your analysis, you analyzed the capabilities 
> claim from the DVD+R/W *feature(s)*.
I mentioned both, as both can only live together.  If the plus profile is 
reported the plus features will be present as well.
> "A device may report this feature only when Profile 10h (DVD-ROM) is 
> reported"
Yes, as in, a drive that can't read DVDs can also not read DVD+R/W discs.
I interpret that as, a drive must be a DVD ROM capable drive to be able to 
do DVD+R/W.
> And in the profile definition, the additional commands support is listed 
> as mandatory. ("Drives identifying Profile 001Ah as current shall support 
> the features listed in Table 221.")
I'm not using the same rev as you do, as it's table 220 in my spec :)
But I'm not sure what you mean ?
All it says is what features should be supported.
And the features that are write related have a small uppercase 1 next to 
them, indicating:
"1 This feature is mandatory only when the Write bit of the DVD+RW Feature 
is set to one."
So the presence of the plus R/W profiles does not guarantee the availability 
of features that deal with writing, only those that deal with reading.
And hence no guarantee that commands such as "Read Disc Information" are 
supported, which you need to be able to recognize blank media.
> Would it be correct then to say that a DVD-ROM that want to claim only 
> recognition of DVD+R/RW but *not* of additional commands has to list only 
> the DVD-ROM profile and the DVD+R/RW feature(s) but *not* list the 
> DVD+R/RW profile(s)?
I think that a DVD-ROM drive that either does or doesn't support the +R/W 
profiles (and features) doesn't need to support the special commands that 
you need to determine blank media.
> I still don't know actually if this would mean that blank DVD+R/RW media 
> are recognized or not.
Bet on the fact that 99% of the ROM drives won't see blank media.
And the availability of plus R/RW features and profiles is no indication nor 
guarantee that the drive can recognise blank media.
> would it be correct to claim that devices claiming DVD+R/RW support have 
> to support blank DVD+R/RW also?
No, only if they set the write bit to one.
Best Regards,
Peter
-------------------------------------------------------
Peter Van Hove, CEO Smart Projects
CD and DVD Data recovery
Peter at Smart-Projects.net
www.Smart-Projects.net
www.IsoBuster.com
-------------------------------------------------------
----- Original Message ----- 
From: "David Burg" <daviburg at windows.microsoft.com>
To: "Peter Van Hove" <Peter at Smart-Projects.net>; <mtfuji5 at avc-pioneer.com>; 
<t10 at t10.org>
Sent: Tuesday, October 17, 2006 10:30 PM
Subject: RE: MMC/Mt Fuji: Clarification about R and RW/Rewritable profiles
> Dear Peter, All,
>
> If I correctly understand your analysis, you analyzed the capabilities 
> claim from the DVD+R/W *feature(s)*. And in the paragraph which you quoted 
> for "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.", is also said eventually "A device may report this 
> feature only when Profile 10h (DVD-ROM) is reported. No additional 
> commands or mode parameters are required."
>
> I am working on drives that reports the DVD+R/RW *profile*, not only the 
> feature. And in the profile definition, the additional commands support is 
> listed as mandatory. ("Drives identifying Profile 001Ah as current shall 
> support the features listed in Table 221.")
>
> Would it be correct then to say that a DVD-ROM that want to claim only 
> recognition of DVD+R/RW but *not* of additional commands has to list only 
> the DVD-ROM profile and the DVD+R/RW feature(s) but *not* list the 
> DVD+R/RW profile(s)?
>
> I still don't know actually if this would mean that blank DVD+R/RW media 
> are recognized or not. As the MMC specification does not make a 
> distinction in the support of DVD+R/RW between blank and recorded media, 
> would it be correct to claim that devices claiming DVD+R/RW support have 
> to support blank DVD+R/RW also?
>
> Best regards,
>
> David Burg,
> Microsoft.
>
> -----Original Message-----
> From: Peter Van Hove [mailto:Peter at Smart-Projects.net]
> Sent: Monday, October 16, 2006 1:26 PM
> To: David Burg; mtfuji5 at avc-pioneer.com; t10 at t10.org
> Subject: Re: MMC/Mt Fuji: Clarification about R and RW/Rewritable profiles
>
> 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$$(J
>>
>> $BAw?.<T(J:     owner-mtfuji5 at avc-pioneer.com
>>
>>
>>
>>
>> $B08 at h(J:	<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:
>> $B7oL>(J:	MMC/Mt Fuji: Clarification about R and RW/Rewritable profiles
>>
>> Hello,
>>
>> During validation of DVD-ROM devices conformance to the MMC command set
>> through
>> the Windows Vista Logo program and MMCTest tool, we were signaled the
>> possible
>> flaw in either our tool or the specification. Our tool query from the
>> drive the
>> list of profiles supported by the drive, and then exercises each of the
>> profiles. Some ROM drives will also report R and/or RW profiles. Thus our
>> tool
>> attempts to validate these profiles, and as part of the validation
>> attempts to
>> validate that the drive recognize blank media properly.
>>
>> Yes, blank media. I understand that hardware manufacturers may very well
>> be
>> reluctant to guarantee this capability on ROM drives. The value of
>> recognizing
>> blank media in a ROM drive that won$B!G(Jt 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.
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> *
>> * For T10 Reflector information, send a message with
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>
>
> 
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