Gutenprint Printer Application

INTRODUCTION

This repository contains a Printer Application for printing with the Gutenprint printer driver. This allows high-quality printing on a wide range of inkjet, lasre, and dye-sublimation printers, especially inkjets from Epson and Canon, PCL laser printers (both monochrome and color), and dye-sublimation photo printers. This driver is especially recommended for photos and fine-art printing. It is also an alternative to the Ghostscript Printer Application for PCL 4/5c/e laser printers.

It uses PAPPL to support IPP printing from multiple operating systems. In addition, it uses the resources of cups-filters 2.x (filter functions in libcupsfilters, libppd) and pappl-retrofit (encapsulating classic CUPS drivers in Printer Applications). The code of pappl-retrofit is derived from the hp-printer-app.

The printer driver itself and the software to communicate with the printer hardware is taken from the Gutenprint project, also the Information about supported printer models and their capabilities.

Your contributions are welcome. Please post issues and pull requests.

Note: Gutenprint is an actively maintained project, therefore it would also be the correct way if Gutenprint gets turned into a Printer Application by its maintainers, or at least this be offered as an alternative to the classic CUPS driver. Especially they should create a native Printer Application, meaning that it does not use PPDs, CUPS filters, and CUPS backends internally. As soon as the Gutenprint project provides a native Printer Application, this Printer Application retro-fitting the CUPS driver will get discontinued.

Please check whether your printer is a driverless IPP printer (AirPrint, Mopria, IPP Everywhere, Wi-Fi Direct Print, prints from phones) as in this case you do not need any Printer Application at all. Most modern printers, even the cheapest models, are driverless IPP printers. Even USB-only printers can be driverless IPP, and you can generally use driverless IPP via USB, try ipp-usb for these cases first.

Properties

• A Printer Application providing the Gutenprint CUPS Raster printer driver and all printer's PPDs of Gutenprint. This allows easy printing in high quality, including photos on photo paper. The specialized CUPSbackend for dye sublimation printers with proprietary USB communication protocols is also included.

• The Printer Application checks the supported number of vendor-specific options/attributes of the installed PAPPL library, PAPPL_MAX_VENDOR and uses the expert PPDs only if 256 or more vendor-specific options are supported, otherwise the simplified PPDs are used. By default, the number is 32 and in the Snap we modify it to be 256, meaning that the Gutenprint Printer Application Snap in the Snap Store uses expert PPDs, while a quick build with make, using an installed standard PAPPL library uses the simplified PPD files.

• Available printer devices are discovered (and used) with CUPS' backends and with Gutenprint's dye-sublimation printer backend in addition and not with PAPPL's own backends. This way dye-sublimation printers are discovered with the correct backend for their totally proprietary communication protocol. Also quirk workarounds for USB printers with compatibility problems are used (and are editable) and Gutenprint output can get send to the printer via IPP, IPPS (encrypted!), and LPD in addition to socket (usually port 9100). The SNMP backend can get configured (community, address scope).

• If you have an unusual system configuration or a personal firewall your printer will perhaps not get discovered. In this situation the fully manual "Network Printer" entry in combination with the hostname/IP field can be helpful.

• PWG Raster, Apple Raster or image input data does not get converted to PostScript or PDF, it is only converted/scaled to the required color space and resolution and then fed into the Gutenprint CUPS Raster driver.

• PDF and PostScript input data is rendered into raster data using Ghostscript.

• The information about which printer models are supported and which are their capabilities is based on the PPD files which get auto-generated by Gutenprint when using it with CUPS. The PPD generator is included in the Snap.

• Standard job IPP attributes are mapped to the driver's option settings best fitting to them so that users can print from any type of client (like for example a phone or IoT device) which only supports standard IPP attributes and cannot retrive the PPD options. Trays, media sizes, media types, and duplex can get mapped easily, but when it comes to color and quality it gets more complex, as relevant options differ a lot in the PPD files. Here we use an algorithm which automatically (who wants hand-edit ~3000 PPD files for the assignments) finds the right set of option settings for each combination of print-color-mode (color/monochrome), print-quality (draft/normal/high), and print-content-optimize (auto/photo/graphics/text/text-and-graphics) in the PPD of the current printer. So you have easy access to the full quality or speed of your printer without needing to deal with printer-specific option settings (the original options are still accessible via web admin interface).

To Do

• PDF test page, for example generated with the bannertopdf filter, or perhaps even a Raster test page.

• Human-readable strings for vendor options (Needs support by PAPPL: Issue #58: Localization support)

• Internationalization/Localization (Needs support by PAPPL: Issue #58: Localization support)

• SNMP Ink level check via ps_status() function (Needs support by PAPPL: Issue #83: CUPS does IPP and SNMP ink level polls via backends, PAPPL should have functions for this)

THE SNAP

Installing and building

To just run and use this Printer Application, simply install it from the Snap Store:

sudo snap install --edge gutenprint-printer-app

Then follow the instructions below for setting it up.

To build the Snap by yourself, in the main directory of this repository run

snapcraft snap

This will download all needed packages and build the Gutenprint Printer Application. Note that PAPPL and cups-filters (upcoming 2.0) are pulled directly from their GIT repositories, as there are no appropriate releases yet. This can also lead to the fact that this Printer Application will suddenly not build any more.

To install the resulting Snap run

sudo snap install --dangerous gutenprint-printer-app_1.0_amd64.snap

Setting up

The Printer Application will automatically be started as a server daemon.

Enter the web interface

http://localhost:8000/

Use the web interface to add a printer. Supply a name, select the discovered printer, then select make and model. Also set the installed accessories, loaded media and the option defaults. Accessory configuration and option defaults can also offen get polled from the printer.

Then print PDF, PostScript, JPEG, Apple Raster, or PWG Raster files with

gutenprint-printer-app FILE

or print with CUPS, CUPS (and also cups-browsed) discover and treat the printers set up with this Printer Application as driverless IPP printers (IPP Everywhere and AirPrint).

See

gutenprint-printer-app --help

for more options.

Use the "-o log-level=debug" argument for verbose logging in your terminal window.

You can add files to /var/snap/gutenprint-printer-app/common/usb/ for additional USB quirk rules. Edit the existing files only for quick tests, as they get replaced at every update of the Snap (to introduce new rules).

You can edit the /var/snap/gutenprint-printer-app/common/cups/snmp.conf file for configuring SNMP network printer discovery.

BUILDING WITHOUT SNAP

You can also do a "quick-and-dirty" build without snapping and without needing to install PAPPL, cups-filters 2.x, and pappl-retrofit into your system. You need a directory with the latest GIT snapshot of PAPPL, the latest GIT snapshot of cups-filters, and the latest GIT snapshot of pappl-retrofit (master branches of each). They all need to be compiled (./autogen.sh; ./configure; make), installing not needed. Also install the header files of all needed libraries (installing "libcups2-dev" should do it).

In the directory with gutenprint-printer-app.c run the command line

gcc -o gutenprint-printer-app gutenprint-printer-app.c $PAPPL_SRC/pappl/libpappl.a $CUPS_FILTERS_SRC/.libs/libppd.a $CUPS_FILTERS_SRC/.libs/libcupsfilters.a $PAPPL_RETROFIT_SRC/.libs/libpappl-retrofit.a -ldl -lpthread  -lppd -lcups -lavahi-common -lavahi-client -lgnutls -ljpeg -lpng16 -ltiff -lz -lm -lusb-1.0 -lpam -lqpdf -lstdc++ -I. -I$PAPPL_SRC/pappl -I$CUPS_FILTERS_SRC/ppd -I$CUPS_FILTERS_SRC/cupsfilters -I$PAPPL_RETROFIT_SRC/pappl/retrofit -L$CUPS_FILTERS_SRC/.libs/ -L$PAPPL_RETROFIT_SRC/.libs/

There is also a Makefile, but this needs PAPPL, cups-filters 2.x, and pappl-retrofit to be installed into your system.

Run

./gutenprint-printer-app --help

When running the non-snapped version, by default, PPD files are searched for in

/usr/share/ppd/
/usr/lib/cups/driver/
/var/lib/gutenprint-printer-app/ppd/

You can set the PPD_PATHS environment variable to search other places instead:

PPD_PATHS=/path/to/my/ppds:/my/second/place ./gutenprint-printer-app server

Simply put a colon-separated list of any amount of paths into the variable. Creating a wrapper script is recommended.

Note that with a standard PAPPL installation only the simplified PPD files of Gutenprint are considered, other PPD files are ignored. If you want to use the expert PPDs of Gutenprint instead, you need to do a simple modification on the PAPPL source code, setting PAPPL_MAX_VENDOR in the pappl/printer.h to 256 instead of 32.

Printers are discovered via CUPS' backends plus Gutenprint's backend for dye-sublimation printers using a proprietary USB communication protocols. Printers are accepted if the model is explicitly supported, but for some printers with common languages (especially PCL 4/5c/e) there is also generic support.

USB Quirk rules in /usr/share/cups/usb and the /etc/cups/snmp.conf file can get edited if needed.

Make sure you have Gutenprint and CUPS (at least its backends) installed.

You also need Ghostscript to print PDF or PostScript jobs.

For access to the test page testpage.ps use the TESTPAGE_DIR environment variable:

TESTPAGE_DIR=`pwd` PPD_PATHS=/path/to/my/ppds:/my/second/place ./gutenprint-printer-app server

or for your own creation of a test page (PostScript, PDF, PNG, JPEG, Apple Raster, PWG Raster):

TESTPAGE=/path/to/my/testpage/my_testpage.ps PPD_PATHS=/path/to/my/ppds:/my/second/place ./gutenprint-printer-app server

LEGAL STUFF

The Gutenprint Printer Application is Copyright © 2020 by Till Kamppeter.

It is derived from the HP PCL Printer Application, a first working model of a raster Printer Application using PAPPL. It is available here:

https://github.com/michaelrsweet/hp-printer-app

The HP PCL Printer Application is Copyright © 2019-2020 by Michael R Sweet.

This software is licensed under the Apache License Version 2.0 with an exception to allow linking against GPL2/LGPL2 software (like older versions of CUPS). See the files "LICENSE" and "NOTICE" for more information.