Subject: Re: IPP> MOD - multiple document each with a different PDL application/octet-stream]

From: Tom Hastings <[email-masked]>
Date: Fri, 26 Sep 1997 17:10:08 PDT

I agree with the thought that the Printer shall apply its auto-sensing
mechanism for EACH document, so that each document could be of a
different document format in a single job (since the client can no longer
specify the document-format separately for each document).

So I think we need to add such a clarification to the description
of the application/octet-stream description.

I suggest adding the following sentence after the second sentence:

If the Printer object supports this value and multiple document jobs, the 
Printer SHALL re-apply its auto-sensing algorithm to each document,
independent of the value of the "ipp-attribute-fidelity" supplied by
the client in the Create-Job operation.

The current 9/26/97 text is:

One special type is 'application/octet-stream'.   If the Printer object
supports this value, the Printer SHALL be capable of auto-sensing the format
of the document data. If the Printer object's default value attribute is set
to 'application/octet-stream' the Printer object not only supports
auto-sensing of the document format, but will depend on the result of
applying its auto-sensing algorithm in the case of missing information not
supplied by the client.  If the client supplies a document format value, the
Printer SHOULD rely on the supplied attribute, rather than trust its
auto-sensing algorithm.  To summarize:

1. If the client does not supply a document format value, the Printer must
rely on its default value setting (which may be 'application/octet-stream'
indicating an auto-sensing mechanism).

2. If the client supplies a value other than 'application/octet-stream', the
client is supplying valid information about the format of the document data
and the Printer object SHOULD trust the client supplied value more than the
outcome of applying an automatic format detection mechanism.  For example,
the client may be requesting the printing of a PostScript file as an
'text/plain' document.  The Printer object SHOULD print a text
representation of the PostScript commands rather than interpret the stream
of PostScript commands and print the result.

3. If the client supplies a value of 'application/octet-stream', the client
is indicating that the Printer object SHOULD use its auto-sensing mechanism 

At 10:15 09/25/97 PDT, Scott Isaacson wrote:
>Randy and Jay and Bob were discussing the issue of how to support
>multiple-documents, each with a different PDL, and only one job level
>attribute called "document-format" (or "job-document-format") to describe
>the whole mess.  There was some concern about IPP's ability to support
>multiple documents each with a different PDL.
>
>I submit, this can be realized when the client supplies nothing or
>supplies the value  "application/octet-stream" (for auto-sensing)
>the job level "document-format".  Then each of the documents could be 
>whatever PDL they wanted. The implementations that support multiple PDLs 
>would probably do the auto-sense anyway at the beginning of each document.
>
>This does not give IPP clients the ability do control the PDL used/sensed
>for each document in Version 1.0, but this more subtle and advanced
>control can be added later.  At least in V1.0, IPP does support multiple
>documents per Job and multiple PDLs among those documents.
>
>Scott
>
>
>************************************************************
>Scott A. Isaacson
>Print Services Consulting Engineer
>Novell Inc., 122 E 1700 S, Provo, UT 84606
>V: (801) 861-7366, (800) 453-1267 x17366
>F: (801) 861-4025, E: [email-masked]
>W: http://www.novell.com
>************************************************************
> 
>
>