UPD Mail Archive: Re: UPD> Re: IPP> MED - Media Standardi

UPD Mail Archive: Re: UPD> Re: IPP> MED - Media Standardi

Re: UPD> Re: IPP> MED - Media Standardized Names Draft D0.4 down-loaded

From: Michael Sweet (mike@easysw.com)
Date: Thu Mar 29 2001 - 15:09:18 EST

  • Next message: Jim Sommer: "Re: UPD> Re: IPP> MED - Media Standardized Names Draft D0.4 down-loaded"

    "Bergman, Ron" wrote:
    > ...
    > I disagee with your proposal for adding printer size restrictions
    > to the document. So far this specification has only involved
    > attributes related to media. Now you are proposing that we add
    > an attribute that is related to printers. This belongs in the
    > appropriate UPnP or IPP or other document that defines how to
    > describe a printer. If we add this then it will be necessary
    > ...

    I'm not sure I agree with this (or maybe I just not understanding
    your objection right); the purpose of this standard/spec is to
    define the names used for media sizes, types, finishes, etc. so
    that other protocols can then use those names uniformly.

    From an implementation standpoint, it may be desireable to have
    media size names that are reserved for representing 1) whether
    custom media sizes are supported, and 2) what the size limits are
    for the device being queried. This allows all protocols to use
    a common method for conveying the custom media size information,
    while the exact values used in the custom size names are determined
    by the device and not the protocols or this spec.

    IPP contains no explicit support for custom media sizes; CUPS
    works around this limitation by supporting a "custom" media size
    keyword and relies on the to know that they can request a custom
    media size using the name "custom.WWWxLLL", where "WWW" and "LLL"
    are the width and length of the media in points (works well for
    a PS-based printing system... :) This only works for CUPS, and
    I have no idea what Microsoft does, for example, with their
    media support under Windows 2000...

    So, I guess what I'm saying is this:

        1. Describe "custom-min" and "custom-max" media size names
           and the format they use. Specify that these names will
           only be present for devices that support custom sizes, and
           that both must appear if they are used at all.

        2. Explicitly state that the values used in the custom-min/max
           names are defined by the device and not the spec.

        3. Explicitly state that the units for media sizes in the
           size names are set by the media spec and not by the
           protocol spec. Units outside the size name can obviously
           be anything the protocol wants...

    #1 will make sure that any client can determine if a device supports
    custom sizes, no matter what protocol is being used.

    #2 will remove any requirement for additional info in the media spec
    on how to manage custom sizes.

    #3 will ensure that the dimensions in size names are consistent no
    matter what protocol is being used.

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

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