Meeting called to order by Ira McDonald at 12pm US Eastern. Minutes taken by Ira McDonald.
Recording of this conference call will be archived at:
http://www.openprinting.org/download/meetingnotes/op-telecons/
OP-Meeting-20170606.mp3
(Recording of second half of meeting also w/ TBD filename)
Attendees
Agenda
- Till added support for the page description language PCLm in the DNS-SD record - In addition to the page description languages PDF, PWG Raster, and Apple Raster, there is also HP's PCLm used for driverless printing (Mopria and Wi-Fi Direct printing standards). - Since we have started to add support for PCLm to cups-filters, ippusbxd needs to advertise PCLm support on appropriate printers in its DNS-SD records so that CUPS and cups-filters (or any other client) can use it.
- Continued working on support for driverless printing.
- See GSoC 2017 status for more driverless printing details.
- By the end of this year, hopefully already with the Ubuntu 17.10 (Artful)
release, we will have full support for all driverless printers (see below).
- system-config-printer - Till has done several changes for driverless
printing support for Ubuntu 17.04 (Zesty) and now Till has submitted them
upstream and they got accepted within 24 hours. Till has submitted more
changes about which he has no answer yet.
- Avahi - Till is now in contact with Avahi's new upstream maintainer, Trent
Lloyd and Trent will add the support for the loopback interface ("lo",
"localhost") needed for locally advertising IPP-over-USB printers vis
DNS-SD.
* PCLm support in cups-filters (completing driverless printing)
- For driverless printing there are (AFAIK) 4 standards, all of them
(fortunately) using DNS-SD for printer discovery and IPP 2.x for
communication with the printer, including querying the printer's
capabilities and options (rather than using static PPDs).
- The difference is in the Page Description Languages (PDLs).
- Standard PDLs (AFAIK, only multi-page)
--------------------------------------------------
IPP Everywhere PWG Raster, PDF
Apple AirPrint Apple Raster, PDF
Mopria PCLm, PWG Raster (?)
Wi-Fi Direct PCLm, PWG Raster
- In free software we have implementations of all these PDLs except PCLm.
Problem was that, until this year's PWG / OpenPrinting Summit, we had no
specs for PCLm and therefore could not develop support for it.
- During the PWG / OpenPrinting Summit Till got the hint from Smith that he
could find the PCLm specs at the Wi-Fi Alliance. Till actually found the
PCLm specs there (well hidden in a ZIP file):
- https://www.wi-fi.org/file/
wi-fi-peer-to-peer-services-technical-specification-package-v12
- (requires filling out a click-thru registration form before download)
- The PCLm format has nothing to do with HP's PCL (5c/e, XL), but instead
is a raster-only, streamable subset of PDF and can even be displayed with
any PDF viewer. But, in contrast PDF, PCLm can be implemented on cheap
printers with low memory and CPU power.
- So Till's plans changed to let the rastertopdf filter of cups-filters get
a second mode with a (slightly) modified output:
- In the first mode, it outputs general PDF with the raster from the input
file embedded plus ICC color management.
- In the second mode it outputs PCLm, PDF with appropriately re-ordered
objects, raster split up in bands according to printer's PCLm IPP
attributes, and no color management.
- Unfortunately, this PCLm change in plans happened only after the student
selection period in GSoC 2017, but fortunately due to the redundancy of
the IPP print dialog backend (see below) we got a student free to put onto
this subject. Sahil is now working on this, mentored Till. Sahil will get
an HP printer for testing and debugging.
- CUPS source code and bug reports are handled on GitHub now
- https://github.com/apple/cups/
- CUPS summary (Till)
- Testing Nilanjana's work on the CUPS backend for the print dialog, Till
has found out that the code of the new concept of CUPS 2.2.x listing
DNS-SD-discovered driverless printers and creating temporary queues for
them on-the fly still had some bugs and reported them.
Mike Sweet has fixed the bugs within a few hours, so that CUPS 2.2.4
will get released with these problems fixed.
- The new functionality for CUPS is also available via the CUPS command
line utilities (List printers with "lpstat -e" and print to the queue
names listed there with "lp" or "lpr", also if CUPS queue does not yet
exist).
- As CUPS is now capable of listing DNS-SD-discovered printers (remote CUPS
queues, IPP printers) and auto-creating temporary print queues on-demand
for them cups-browsed is not necessarily needed any more for basic use
cases.
- According to Mike Sweet, the PPD support in CUPS will stay for as long as
printer-model-specific software (aka printer drivers) is still needed.
PPDs will go away when we have completely switched over to driverless
printing. So it seems that no replacement for the PPD concept will be
designed and the disappearance of PPD support depends on the success of
driverless printing.
- CUPS v2.2.3 release on 28 March 2017 (Mike)
- The IPP backend could get into an infinite loop for certain
errors, causing a hung queue (<rdar://problem/28008717>)
- The scheduler could pause responding to client requests in
order to save state changes to disk
(<rdar://problem/28690656>)
- Added support for PPD finishing keywords (Issue #4960, Issue
#4961, Issue #4962)
- The IPP backend did not send a media-col attribute for just
the source or type (Issue #4963)
- IPP Everywhere print queues did not always support all print
qualities supported by the printer (Issue #4953)
- IPP Everywhere print queues did not always support all media
types supported by the printer (Issue #4953)
- The IPP Everywhere PPD generator did not return useful error
messages (Issue #4954)
- The IPP Everywhere finishings support did not work correctly
with common UI or command-line options (Issue #4976)
- Fixed an error handling issue for the network backends (Issue
#4979)
- The default cupsd.conf file did not work on systems compiled
without Kerberos support (Issue #4947)
- The "reprint job" option was not available for some canceled
jobs (Issue #4915)
- Updated the job listing in the web interface (Issue #4978)
- Fixed some localization issues on macOS
(<rdar://problem/27245567>)
- CUPS Filters summary (Till)
- Currently released is 1.14.0.
- Principal changes:
- Workaround for IPP-over-USB printer support until localhost support
for Avahi is completed.
- Configuration option for auto-creating queues only for IPP-over-USB
printers (local IPP printers).
- cups-browsed development will continue, as an add-on for more
sophisticated configurations, especially in enterprise networks.
- cups-browsed will provide the following enhancements against a pure
CUPS/print dialog setup:
o Legacy CUPS server (1.5.x and older) interoperability
o Interoperability with old print dialogs (which do not use
cupsEnumDests() and new CUPS API)
o Load balancing of clustered remote CUPS queues
o Support for legacy (IPP 1.x) IPP network printers
o Support for new driverless printing technologies not yet supported
by CUPS (like PCLm)
o Fine-grained filtering of which remote printers are available
- cups-browsed will get configuration options to integrate with current
CUPS and to independently activate and de-activate said enhancements.
Also the use of the CUPS PPD API will get removed in cups-browsed.
- CUPS Filters v1.14.1 release work-in-progress (Till)
- libcupsfilters: Let PPD generator do case-insensitive comparisons for PWG
Raster color spaces, as some printers (Epson) do not use the standard-
conforming all-lowercase form for them (CUPS Issue #4998).
- CUPS Filters v1.14.0 release on 15 May 2017 (Till)
- cups-browsed: When a printer is discovered via DNS-SD on the
"lo" (loopback) interface the printer is not reliably
accessible through the reported host name (which is the
network host name of the local machine). Until this problem
is fixed in Avahi, we create queues for such printers with a
URI based on the IP address. This is a workaround until
Avahi fully supports the "lo" interface.
- cups-browsed: Added new setting "LocalOnly" for the
CreateIPPPrinterQueues in cups-browsed.conf. With this new
setting (which is the default from now on) only for local
printers made available as IPP printers (like IPP-over-USB
printers with ippusbxd) queues are auto-created. With this
we can follow the common standard of distributions where USB
printers are automatically set up and network printers not.
- cups-browsed: Fixes and improvements in comments and debug
messages:
1. Bonjour -> DNS-SD;
2. When a remote CUPS class is discovered, tell that it is a class;
3. Show network interface and IPv4/IPv6 when a DNS-Sd service appears or
disappears.
- cups-browsed: Added ./configure script option
"--enable-auto-setup-driverless" to let cups-browsed
automatically set up IPP network printers by default.
- It turns out that, with the new functionality of CUPS 2.2.x, the CUPS
backend (Nilanjana, mentored by Till) for print dialog also provides
the full functionality of the IPP backend, without any extra effort.
- So the IPP backend (Sahil, mentored by Danny) becomes redundant.
- Therefore Till has reassigned Sahil to add PCLm support to cups-filters,
and Till will now mentor him.
- Danny will now mentor Yash, who works on patching LibreOffice to take
the new print dialog backends. Till was Yash's mentor before.
- The new cupsEnumDests() API function not only lists the print queues
of the local CUPS daemon but also the DNS-SD-discovered IPP printers,
which are remote CUPS queues, IPP network printers (only if they do
driverless, meaning IPP 2.x plus currently one of the PDLs PWG Raster
and Apple Raster), and (after a small change in Avahi happening soon)
local IPP-over-USB printers (they all do driverless by standard).
Accessing any of these printers which do not have a CUPS queue at the
local CUPS daemon will make CUPS automatically create a temporary queue.
Formerly, the CUPS backend was supposed to only serve the printers of the
local CUPS daemon and the IPP backend the DNS-SD-advertised IPP printers
without a queue at the local CUPS daemon. This split made things
artificially awkward and Nilajana's CUPS backend work already covers all
this without special effort. Therefore we have dropped the IPP backend
project in GSoC 2017.
- Student Mentor Project
--------------------------------------------------------------------------
Nilanjana Till CUPS backend (unchanged)
Sahil Till Add PCLm support to cups-filters
Yash Danny Patch LibreOffice to support new print dialog backends
- Currently, we are working on the design for a communication protocol/API
between the print dialogs and the backends. We have settled on using D-Bus,
to avoid any dependency of a print dialog on the library of GUI toolkit B
if the dialog itself is for GUI toolkit A.
- Nilanjana and Yash are driving forward the D-Bus interface design work.
- Smith Kennedy and Aveek Basu are arranging for a PCLm-compatible printer
for Sahil so that he can test and debug his code.
- We have now 5 students on the print dialog work and 2 on cups-filters.
- GSoC 2017 Schedule
- 19 January to 9 February - Mentors submit organization applications
- 27 February - GSoC approves mentoring organizations
- 27 February to 20 March - Students discuss GSoC projects
- 20 March to 3 April - Students apply for GSoC projects
- 1 May - GSoC approves projects and Students
- 30 May - GSoC coding begins
- 26-30 June - GSoC Phase 1 evaluations
- 24-28 July - GSoC Phase 2 evaluations
- 21-29 August - GSoC "pencils down"
- Students fill out completion forms and evaluate Mentors
- 29 August to 5 September - Mentors submit Student evaluations
- 6 September - GSoC announces final results
- Late October - GSoC Mentor Summit at Google
- We will use Aveek's very successful recruitment concept of starting with finding students already in January again as we have been more effective in finding good students. - GSoC OP project ideas for 2018: - Implementation of IPP System Services - Implementation of IPP Scan (driverless scanning)
- Joint PWG/OP Summit as Virtual F2F (PWG Host via WebEx) - 2-4 May 2017
- http://www.pwg.org/chair/meeting-info/may-2017-virtual.html
- PWG as Virtual F2F (PWG Host via WebEx) - 9-10 August 2017
- http://www.pwg.org/chair/meeting-info/meetings.html
- IPP Everywhere Self-Certification - PWG 5100.20-2016 - Active
- http://ftp.pwg.org/pub/pwg/candidates/
cs-ippeveselfcert10-20160219-5100.20.pdf
- REQUIRED for PWG IPP Everywhere Logo usage
- HP has certified 89 IPP Everywhere printers!
- https://www.pwg.org/ippeveselfcert
- IPP Everywhere Self-Certification website - opened 25 March 2016
- ONLY available to PWG members (but FREE to PWG members)
- JDFMAP (Ira/Rick Yardumian) - Stable draft
- http://ftp.pwg.org/pub/pwg/sm3/wd/wd-smjdfmap10-20170504.pdf
- PWG Last Call started 05/18/17 ends 06/15/17
- Schedule - PWG Formal Vote in Q3 2017 as Best Practices
- IPP 3D Print Job Ticket (Mike) - Stable draft
- http://ftp.pwg.org/pub/pwg/ipp/wd-20170504.pdf
- PWG Last Call started 05/25/17 ends 06/16/17
- Schedule - PWG Formal Vote in Q3 2017 as Candidate Standard
- IPP WG Charter (Ira) - Stable draft
- http://ftp.pwg.org/pub/pwg/ipp/wd/wd-ipp-charter-20170519.pdf
- IPP WG and PWG SC approved in May 2017
- PWG Call for Objections started 05/25/17 ends 06/09/17
- Schedule - PWG Approval in June 2017
- IPP System Service (Mike/Ira) - Interim draft
- http://ftp.pwg.org/pub/pwg/ipp/wd/wd-ippsystem10-20170509-rev.pdf
- PWG review on 05/03/17
- Schedule - Prototype draft in Q3 2017 - prototype in "ippserver"
- IPP Get-User-Printer-Attributes (Smith) - whitepaper
- http://ftp.pwg.org/pub/pwg/ipp/whitepaper/tb-userop-20170524-rev.pdf
- Schedule - TBD
- IPP Presets (Smith) - whitepaper
- http://ftp.pwg.org/pub/pwg/ipp/whitepaper/tb-ipp-preset-20170418.pdf
- Schedule - TBD
- IPP Authentication (Smith) - whitepaper
- http://ftp.pwg.org/pub/pwg/ipp/whitepaper/ipp-authentication.pdf
- Schedule - TBD
- Trusted Computing Group in Hamburg, Germany - 12-16 June 2017 - http://www.trustedcomputinggroup.org/ - ESCAR USA 2017 - 21-22 June 2017 - https://www.escar.info/escar-usa.html - PWG as Virtual F2F (PWG Host via WebEx) - 9-10 August 2017 - http://www.pwg.org/chair/meeting-info/meetings.html
Open Action Items
Next OP US/Europe/Brazil Conference Calls
- Note - US Independence Day holiday is on 4 July 2017
- Tuesday 11 July 2017, Daytime
- US
9am in San Francisco - US PDT (Pacific Daylight Time)
10am in Colorado - US MDT (Mountain Daylight Time)
11am in Chicago - US CDT (Central Daylight Time)
12pm in New York - US EDT (Eastern Daylight Time)
- Europe
6pm in Berlin - CEST (Central Europe Summer Time)
- Brazil
1pm in Belo Horizonte - BRT (Brasilia Time)
US: +1 641-715-3814
Germany: +49 (0) 221 98203421
Brazil: +55 61 4040-4460
Japan: +81 (0) 3-5050-5070
Participant Access Code: 622393#
(note that local numbers for many other countries are available,
also cellphone apps, VOIP support, etc. - please email Till for
details)
- Note: PWG as Virtual F2F (PWG Host via WebEx) - 9-10 August 2017
- Tuesday 1 August 2017, Daytime
- US
9am in San Francisco - US PDT (Pacific Daylight Time)
10am in Colorado - US MDT (Mountain Daylight Time)
11am in Chicago - US CDT (Central Daylight Time)
12pm in New York - US EDT (Eastern Daylight Time)
- Europe
6pm in Berlin - CEST (Central Europe Summer Time)
- Brazil
1pm in Belo Horizonte - BRT (Brasilia Time)
US: +1 641-715-3814
Germany: +49 (0) 221 98203421
Brazil: +55 61 4040-4460
Japan: +81 (0) 3-5050-5070
Participant Access Code: 622393#
(note that local numbers for many other countries are available,
also cellphone apps, VOIP support, etc. - please email Till for
details)
- Note - US Labor Day holiday is on 4 September 2017 - may delay OP call
- Tuesday 5 September 2017, Daytime
- US
9am in San Francisco - US PDT (Pacific Daylight Time)
10am in Colorado - US MDT (Mountain Daylight Time)
11am in Chicago - US CDT (Central Daylight Time)
12pm in New York - US EDT (Eastern Daylight Time)
- Europe
6pm in Berlin - CEST (Central Europe Summer Time)
- Brazil
1pm in Belo Horizonte - BRT (Brasilia Time)
US: +1 641-715-3814
Germany: +49 (0) 221 98203421
Brazil: +55 61 4040-4460
Japan: +81 (0) 3-5050-5070
Participant Access Code: 622393#
(note that local numbers for many other countries are available,
also cellphone apps, VOIP support, etc. - please email Till for
details)