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

David Burg daviburg at windows.microsoft.com
Thu Oct 19 10:19:52 PDT 2006 

* From the T10 Reflector (t10 at t10.org), posted by:
* David Burg <daviburg at windows.microsoft.com>
*
Ouch indeed,
So you mean that a DVD-ROM drive shall never report the DVD+R/RW profiles?
Because we at Microsoft have a failure in our tests precisely because of such
DVD-ROM drives.
Best regards,
David Burg.
-----Original Message-----
From: Bill McFerrin [mailto:billmc37 at ctesc.net] 
Sent: Thursday, October 19, 2006 7:05 AM
To: David Burg
Cc: mtfuji5 at avc-pioneer.com; t10 at t10.org
Subject: Re: MMC/Mt Fuji: Clarification about R and RW/Rewritable profiles
Ouch,
It gets worse. The paragraph below the DVD+RW Profile states that the
Write bit must be set to one. I will be posting rev 4 this weekend with
fixes based upon the ANSI editor's comments. The clarification here is
to remove the footnotes that cause confusion.
Kind Regards,
Bill
David Burg wrote:
> * From the T10 Reflector (t10 at t10.org), posted by:
> * David Burg <daviburg at windows.microsoft.com>
> *
> Hi Bill,
>
> You said: "Each DVD+ profile requires the ability to record."
>
> But the spec says in a note for the write features of the + profiles: "1
This feature is mandatory only when the Write bit of the DVD+RW Feature is
set to one."
>
> Does DVD+ profile really require the ability to record?
>
> Best regards,
>
> David Burg.
>
> -----Original Message-----
> From: Bill McFerrin [mailto:billmc37 at ctesc.net] 
> Sent: Wednesday, October 18, 2006 4:16 PM
> To: David Burg
> Cc: mtfuji5 at avc-pioneer.com; t10 at t10.org
> Subject: Re: MMC/Mt Fuji: Clarification about R and RW/Rewritable profiles
>
> Hi David,
> There is less to this than you think.
>
> In the beginning (sort of), there was DVD-ROM and no writables. Some
> DVD-ROM drives rejected recorded DVD+RW discs (and sometimes others as
> well). We wanted a simple way for a DVD-ROM Drive to claim the ability
> to read recorded DVD+ discs. Each DVD+ feature followed that idea for
> consistency.
>
> Each DVD+ profile requires the ability to record.
>
> That's it.
>
> Kind Regards,
> Bill McFerrin
>
> David Burg wrote:
>   
>> * 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
>>>> * 'info t10' (no quotes) in the message body to majordomo at t10.org
>>>>
>>>>	   
>>>>	     
>>>	
>>>	  
>> *
>> * For T10 Reflector information, send a message with
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>>
>>   
>>     
>
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