[sane-devel] Fwd: [janitorial] New backend: escl

[Brian Potkin]

---------- Forwarded message ---------
From: Brian Potkin <claremont102 at gmail.com>
Date: Sun, 15 Dec 2019 at 20:41
Subject: Re: [sane-devel] [janitorial] New backend: escl
To: Till Kamppeter <till.kamppeter at gmail.com>


On Sun, 15 Dec 2019 at 15:37, Till Kamppeter <till.kamppeter at gmail.com> wrote:

> Seeing that my HP does eSCL, I have investigated the source code of HPLIP, the
> free software HP printer/MF device driver suite, and it seems to also support
> eSCL for scanning, containing the source file
>
> scan/sane/escl.c
> scan/sane/escl.h

Looks like it.

> This could perhaps contain missing pieces for your eSCL backend, like PDF (or
> any uncompressed raster) output, USB support, ...
>
> In the list of supported models
>
> data/models/models.dat
>
> on all with "scan-type=9" sSCL is used by HPLIP (see also io/hpmud/hpmud.h), but
> there are more models, like ny DeskJet 2540 which supports eSCL according to its
> DNS-SD record.

Upstream HPLIP do not document scan-type=9 at all. They also fail to
mention that it
requires a non-free plugin. When treating a user problem with such a
device it is
downhill all the way when getting help from them. If the missing
pieces are in a plugin
we have problems.

Ordissimo and Touboul Nathane have sorted out most of  my ENVY 4520 problems.
See Issues at https://gitlab.com/sane-escl/sane-escl.

I believe SCL is an HP protocol. What about eSCL? And what does "e"
stand for? Nobody
knows. Nobody, particulary HP, says anything.

--
Brian.