IPP Mail Archive: RE: IPP> Document-format attribute.. [ipp-

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

From: McDonald, Ira (imcdonald@sharplabs.com)
Date: Thu Mar 30 2000 - 12:23:26 EST

  • Next message: Manros, Carl-Uno B: "RE: IPP> Document-format attribute.. [ipp-mod] clarification"

    Hi Michael,

    Point taken about the SHOULD and SHOULD not.

    Print data streams that are not MIME registered are a serious
    problem for interworking - the vendors should be registering
    them.

    Lastly, I think that a Printer object CANNOT only support
    'application/octet-stream' - because the formats actually
    decoded for 'application/octet-stream' PDL detection are
    supposed to be a (subset of) the explicit formats listed
    in 'document-format-supported' attribute. If a Printer
    object lists only 'application/octet-stream' then interworking
    is guaranteed never to work.

    Cheers,
    - Ira McDonald

    -----Original Message-----
    From: Michael Sweet [mailto:mike@easysw.com]
    Sent: Thursday, March 30, 2000 8:07 AM
    To: McDonald, Ira
    Cc: 'harryl@us.ibm.com'; Hastings, Tom N; anthony.porter@computer.org;
    ipp@pwg.org; venky@teil.soft.net
    Subject: Re: IPP> Document-format attribute.. [ipp-mod] clarification

    "McDonald, Ira" wrote:
    >
    > Hi folks,
    >
    > I agree with Harry that we should further revise this paragraph
    > to indicate that a client MUST specify a particular document
    > format when known and MUST NOT use 'application/octet-stream'
    > instead.

    Um, that probably won't work too well, since many printer-specific
    data streams do not have registered MIME types (e.g. Canon, ALPS,
    EPSON, Lexmark, etc.), and a generic print server (e.g. JetDirect,
    Axis print server, etc.) probably won't know enough to be able to
    enumerate the supported MIME types for the actual device.

    SHOULD and SHOULD NOT are probably more appropriate if we are
    trying to "encourage" rather than "enforce".

    Also, the application/octet-stream information should probably be
    updated to reflect a special case for printer objects that list
    only application/octet-stream for document-format-supported.
    That is, if a client knows the MIME type but the printer object
    only supports application/octet-stream, then the printer object
    is just acting as a "dumb" printer buffer and the client must
    only use the default document format or pass
    application/octet-stream.

    -- 
    ______________________________________________________________________
    Michael Sweet, Easy Software Products                  mike@easysw.com
    Printing Software for UNIX                       http://www.easysw.com
    



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