cups-browsed: Print queue for pwg-raster local printer is not created.

[dheeraj135]

If we have a local printer(ippeveprinter/ippserver) which supports only image/pwg-raster and application/octet-stream, then cups-browsed(default cups-browsed.conf file) is not able to create a print queue for this printer.

If we set CreateIPPPrinterQueues All then the print queue is created.
But if we use CreateIPPPrinterQueues Everywhere or CreateIPPPrinterQueues Driverless then the print queue is not created.

Attribute file of the printer: pwg.attr.txt

[dheeraj135]

To create ipp printer supporting only image/pwg-raster and application/octet-stream, simply use the attribute file as: ippserver -a pwg.attr.txt pwg_test_printer.
Alternatively, build ippsample for this source: https://github.com/dheeraj135/ippsample. Then use the ippeveprinter utility as: ./ippeveprinter pwg_test_printer

[tillkamppeter]

I have found out what the problem is.
An IPP printer which supports PWG Raster do not only have to tell this in its "document-format-supported" attribute but also provide the "pwg-raster-document-resolution-supported" to tell a client which resolutions (in dpi) the PWG Raster files need to have so that the printer is able to print them. A typical laser printer would list 300 dpi and 600 dpi here.

[tillkamppeter]

So the bug is in the printer emulator(s) of ippsample (and also CUPS). If a certain PDL is supported also the keywords for the parameters of the PDL need to be present. This is valid for Apple Raster, PWG Raster, and PCLm.
Please report bugs on the appropriate upstream projects and also take this into account in the Printer Application framework, especially for the raster-only mode,

[tillkamppeter]

The attributes AFAIR are:
Apple Raster:

• urf-supported

PWG Raster:

• pwg-raster-document-type-supported
• pwg-raster-document-resolution-supported
• pwg-raster-document-sheet-back

PCLm:

• pclm-source-resolution-supported
• pclm-source-resolution-default
• pclm-strip-height-supported
• pclm-strip-height-preferred
• pclm-raster-back-side
• pclm-compression-method-preferred

[dheeraj135]

@tillkamppeter
From the attributes file, we have the following attributes:
ATTR resolution pwg-raster-document-resolution-supported 300x300dpi,600x600dpi
ATTR keyword pwg-raster-document-type-supported "black_1","sgray_8"
ATTR mimeMediaType document-format-supported "application/octet-stream","image/pwg-raster"

pwg-raster-document-sheet-back is missing but this attribute is CONDITIONALLY REQUIRED. Reference: Pwg raster format. Page 37.

So, I don't think this bug is in the emulator.

[tillkamppeter]

I have found what went wrong, the "pwg-raster-document-resolution-supported" was checked as a keyword type but is of resolution type. I have fixed this in commit 01726b3 now.
Thanks for the bug report.