Re: Support for Apple raster printers now in CUPS and cups-browsed
On Sat 10 Dec 2016 at 16:01:05 -0200, Till Kamppeter wrote:
> Thank you for testing, see my further comments below.
No problem; it was fun. I love it when new techniques are devised and
refined to produce something which opens up possibilities. People
thought the sky had fallen in when IPP browsing disappeared from CUPS,
but, especially with the involvement of openprinting, we appear to be
still at the top of our game.
Thank you, too, for the ideas you have sprinkled throughout your
response. Knowing where we are and where we need to get to is important.
> On 12/10/2016 03:03 PM, Brian Potkin wrote:
> >I have an HP ENVY 4500 series inkjet machine. It comes with AirPrint,
> >which has not seen any use because I do not have an i-device. If it is
> >of interest avahi-browse shows the text record as
> >
> > txt = ["Scan=T" "Duplex=T" "Color=T"
> > "UUID=1c852a4d-b800-1f08-abcd-308d99fafac2"
> > "note=" "adminurl=http://envy4500.local."; "mac=30:8d:99:fa:fa:c2"
> > "priority=40" "usb_MDL=ENVY 4500 series" "usb_MFG=HP"
> > "product=(HP ENVY 4500 series)" "ty=ENVY 4500 series"
> > "kind=document,envelope,photo" "PaperMax=<legal-A4"
> > "pdl=application/vnd.hp-PCL,image/jpeg,application/PCLm,image/urf"
> ^^^^^^^
> > "qtotal=1" "txtvers=1"]
> >
>
> The "image/urf" under the PDLs (Page Description Languages) tells that the
> printer accepts Apple Raster, which usually means that it is an AirPrint
> printer.
>
> >A PPD is generated for an everywhere queue and for the auto-setup with
> >the CreateIPPPrinterQueues directive of cups-browsed. The PPD fails with
> >cupstestppd because of multiple occurences of a couple of options. A bug
> >in its autogeneration?
> >
>
> Most probably it is a bug in the printer firmware. As it occurs also with
> other printers (a guy from Lexmark tested one of their printers for me and
> observed the same problem) it would be better if the PPD generator handles
> this. Therefore I reported this bug to CUPS upstream:
>
> https://github.com/apple/cups/issues/4933
>
> Please attach the auto-generated PPD for your printer (HP ENVY 4500) to this
> bug report. Note that you have to rename it adding .txt to the end of the
> filename, otherwise GitHub's issue tracker does not accept it.
Yes, thanks. I saw the report not half-an-hour ago. I'll add to it by
tomorrow.
> >Anyway, printing takes place. Nothing complex was used for the test so I
> >suppose it remains to be seen how well it would stand up for something
> >serious. But at this point I'm impressed. I suppose if my printer needed
> >a non-free plugin (it doesn't) I would now have a way to dispense with
> >it.
> >
>
> HP printers using the proprietary HPLIP plug-in for a driver extension will
> not need it any more when printing driverless instead of via HPLIP. But if
> an HP printer needs the plug-in for a firmware file will still need it even
> if they could print driverless, but I think there is no such printer as
> AirPrint printers are designed to work stand-alone without any computer and
> therefore must have their firmware built-in.
>
> But even better is that you can drop things like awkward, proprietary driver
> packages for Brother and Samsung printers for example. And you will be able
> to print on many printers whose manufacturers I did not mention here.
That was my thinking too. However, I imagine we are still dependent on
the quality of urf support on the printer?
> >I've been trying to think of any disadvantages to driverless printing
> >over using a hpcups or Gutenprint PPD. Are there any?
>
> Currently driverless printing is network-only, as it requires IPP for
> querying the capabilities from the printer so that one can generate the PPD
> and it also need IPP to send option settings to the printer (as IPP
> attributes). Especially PDF and JPEG which are also valid formats on many
> driverless printers do not allow embedding option settings in the data
> files.
>
> We need to investigate and test more on IPP-over-USB to make driverless
> printing also working via USB.
>
> Driverless printing usually allows only adjustments on the printing as they
> are thought out by the printer manufacturers, whereas Gutenprint allows a
> lot of fine tuning which goes far beyond the manufacturer's possibilities.
> So photo enthusiasts will probably like more to print via Gutenprint.
>
> Another point are the scanners in multi-function devices. These still need
> (SANE) drivers and for HP the driver is in HPLIP. The hpcups of HPLIP is not
> needed any more for driverless (IPP Everywhere and AirPrint) printers
> (running on the network), and hpcups does not really add any extra
> adjustments, in contrary to Gutenprint, but note that HPLIP is from HP and
> not from a third party.
Scanners are a problem, aren't they. As far as I can see they often
require a proprietry driver for multifunctional devices. I have the ENVY
2002 working very well without HPLIP (but with SANE and hpaio) over the
network.
Regards,
Brian.
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