[sane-devel] sane-airprint

[Till Kamppeter]

On 24/12/2019 14:47, Alexander Pevzner wrote:
> Hi, everybody,
> 
> Merry Christmas and happy New Year!
> 
> I want to announce the sane-airpring backend, which implements scanning over 
> eSCL protocol:
> 
> https://github.com/alexpevzner/sane-airscan
> 
> Well, I'm aware about the sane-escl backend. Actually, the sane-escl was 
> published when my backend was half-implemented, so I decided to continue. So 
> after years of waiting, now we have two eSCL backends to choose from, sorry for 
> confusion :-)
> 
> The key differences between my backend (sane-airprint) and sane-escl are:
> 1) sane-escl uses CURL, while my backend uses libsoup. CURL's initialization 
> requirements are nearly impossible to implement in a loadable plugin, so if 
> frontend (or some of its components) also use CURL, sporadic crashes are possible
> 2) My backend implements full support of ADF, including simplex, duplex and 
> multipage scan
> 3) Early cancel. sane-airscan allows to cancel a job far before its completion, 
> leaving scanner in a correct state (my Kyocera ECOSYS is very sensitive to this 
> matter).
> 4) sane-airscan keeps and decodes images in memory, and doesn't use temporary 
> files. Memory footprint is reasonable low: images are decoded line-by-line as 
> soon as sane_read consumes the data
> 5) sane_cancel() is safe to be called from signal handler, as required by SANE 
> standard
> 6) sane_get_select_fd() and sane_set_io_mode() are fully implemented
> 7) sane_airprint correctly supports IPv6 addresses
> 
> Looking forward for some feedback.
> 

Great, so we have 3 eSCL backends now: sane-escl, AirSane, and sane-airscan. 
Thanks to all of you to support this big group of scanners, probably all in 
printer/scanner-multi-function devices which do AirPrint.

Alexander, could you also try to scan on a USB-connected device via ippusbxd 
(https://github.com/OpenPrinting/ippusbxd)? Note that you need to supply the URI 
manually (should be "http://localhost:60000/eSCL/...") as ippusbxd does not 
support yet DNS-SD registration for multi-function devices 
(https://github.com/OpenPrinting/ippusbxd/issues/11).

Do not try to build USB support directly into your backend, as this could block 
printing and device administration (and it would probably also be duplication of 
ippusbxd's functionality).

    Till