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

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

Michael Sweet mike at easysw.com
Thu Mar 29 15:09:18 EST 2001


"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 at easysw.com
Printing Software for UNIX                       http://www.easysw.com



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