IPP> Document-format attribute.. [ipp-mod] clarification

IPP> Document-format attribute.. [ipp-mod] clarification

IPP> Document-format attribute.. [ipp-mod] clarification

Hastings, Tom N hastings at cp10.es.xerox.com
Mon Apr 3 20:36:22 EDT 2000


See my comments preceded by TH>

Tom

-----Original Message-----
From: harryl at us.ibm.com [mailto:harryl at us.ibm.com]
Sent: Tuesday, March 28, 2000 09:35
To: Hastings, Tom N
Cc: anthony.porter at computer.org; ipp at pwg.org; venky at teil.soft.net
Subject: RE: IPP> Document-format attribute.. [ipp-mod] clarification





I'm OK with the clarification. You are basically just adding the fact that
the sniffing method is implementation dependent... right?

TH> Yes.


More important, to me, is to encourage that no client ever use
application/octet-string when they are aware of and capable of indicating
the correct document format in mimeMediaType!

TH> I agree.  I scanned the model document and found the following:

3.2.1.1 Print-Job Response says:

If the client omits this "document-format" operation attribute, the Printer
object MUST respond as if the attribute had been supplied with the value of
the Printer object's "document-format-default" attribute.  It is RECOMMENDED
that the client always supply a value for "document-format", since the
Printer object's "document-format-default" may be
'application/octet-stream', in which case the returned attributes and values
are for the union of the document formats that the Printer can automatically
sense.  For more details, see the description of the 'mimeMediaType'
attribute syntax in section 4.1.9.


I think this is good enough.  However, the word "recommended" wasn't in
caps, so I'll change that with the RFC editor, ok?

Tom





Harry Lewis
IBM Printing Systems




"Hastings, Tom N" <hastings at cp10.es.xerox.com>
Sent by: owner-ipp at pwg.org
03/28/00 09:27 AM


        To:     anthony.porter at computer.org, "'Venkatesh'"
<venky at teil.soft.net>,
ipp at pwg.org
        cc:
        Subject:        RE: IPP> Document-format attribute.. [ipp-mod]
clarification


I searched both the Model and the Implementer's Guide and there isn't
anything that explains what "auto-sensing" is.

So, ok to add the following clarification to the [ipp-mod] document in
section 4.1.9.1:

 using an implementation-dependent method that examines some number of
octets of the document data

so that it reads:

4.1.9.1 Application/octet-stream -- Auto-Sensing the document format

One special type is 'application/octet-stream'.  If the Printer object
supports this value, the Printer object MUST be capable of auto-sensing
the
format of the document data using an implementation-dependent method that
examines some number of octets of the document data, either as part of the
create operation and/or at document processing time.

Or should we put something similar in the Implementer's Guide, instead?

Tom


-----Original Message-----
From: Anthony Porter [mailto:anthony.porter at computer.org]
Sent: Monday, September 06, 1999 03:08
To: 'Venkatesh'; ipp at pwg.org
Subject: RE: IPP> Document-format attribute..


It can usually tell from the first few bytes of the file.  For example,
PostScript files start with %!PS and PDF files start with %PDF.  Gif files
start with GIF89 and so on.

-----Original Message-----
From: owner-ipp at pwg.org [mailto:owner-ipp at pwg.org]On Behalf Of Venkatesh
Sent: 06 September 1999 08:54
To: ipp at pwg.org
Subject: IPP> Document-format attribute..


Hello Everybody..
 I have a doubt in the "document-format" attribute that the client
optionally specifies in the request..(according to IPP/1.1 draft)
The draft says that if theclient supplies this attribute and its value
is
'application/octet-stream' then the server needs to aut-sense the
document..
Can anyone explain me how does this autosensing happens.......
How actually will the Printer Object  perform this task...

Thank You







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